* GB784968 (A)

Description: GB784968 (A) ? 1957-10-23

Improvements relating to clutches

Description of GB784968 (A)

PATENT SPECIFICATION Inventors: EMIL FUNKE and WERNER 7 PEDDINGHAUS Date of application and filing Complete Specification: Nov 7, 1955. No 31793/55. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 80 ( 2), CIA( 3 A: 4: 7 A: 13 A), PIM( 1 B: 4 B), P 4. International Classification:-FO 6 d. COMPLETE SPECIFICATION Improvements relating to Clutches We, PAUL CARL PEDDINGHAUS and WERNER PEDDINGHAUS, both German Citizens, trading as the firm of PAUL FERD PEDDINGH Aus, of Gevelsberg i/Westf Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - In industrial machines and especially machine tools, it is often necessary that, on disconnection of the power drive, the machine should stop with the main driving shaft in an accurately determined position. Such machines are, therefore, driven through controllable clutches, which disengage at the termination of a complete revolution, or of a number of complete revolutions. The present invention relates to a clutch in which the driving member comprises an annular felloe having slots or recesses disposed around its inner periphery and the driven member has a radially movable detent which is arranged to engage with any of the slots, or recesses and is movable by a control member into a position to disengage the clutch and stop the driven member in a predetermined position. According to the invention, the slots or recesses and the portion of the detent arranged to engage therein are tapered radially outwards

The connection between the two members of the clutch is, therefore, without play, and will be properly maintained even after a certain amount of wear has occurred. The clutch engages almost immediately and couples positively on actuation of its control and which, therefore, prevents initial racing of the driving member. The driving member may comprise a gear wheel having a sufficiently large diameter to enable a large number of slots to be formed on the inner periphery of the felloe On operating the clutch, therefore, the gear wheel need rotate through only a small angle before one of the slots is engaged by the detent and lPrice 3 s -6 d l 84968 the two members of the clutch are positively coupled. As the negative torques produced by an initial overrunning of the driven portion of 50 the coupling are smaller than the positive torques transmitted during drive, the clutch can advantageously be formed in such a manner that the flanks of the slots leading in the direction of rotation of the driving mem 55 ber are of less height than the trailing flanks, there being provided in front of the slots oblique or curved surfaces extending gradually towards the inner circumference of the felloe This affords the advantage that the 60 detent is guided into and engages with the first slot reaching it when the driving member is rotated even when the speed is high, and the whole surface of the leading flank of the slot is effective immediately at the be 65 ginning of the transmission of the driving torque. An example of a clutch according to the invention is shown in the accompanying drawings in which: 70 Figure 1 shows an elevation of the clutch; Figure 2 shows a cross-section taken on the line 1-1 of Figure 1; and Figure 3 shows a plan view of the clutch. An arm 2 is attached by a hub to a shaft 75 1 A detent 3 radially displaceable in a bore 4 of the arm 2, is pressed outwards by a helical spring 7 and is formed with a laterally projecting stud 5 The stud 5 projects through a slot 6 in the arm 2 A rail 8 80 pivoted on a pin 9 controls the clutch The pin 9 is carried on a bracket 10 which is attached to the body of the machine to be driven through the clutch The rail 8 is connected to a lever 12 by which it may be 85 moved from an operative position shown by broken lines in Figure 3 to an inoperative position shown in the Figure by full lines. The base of the rail 8 is formed with a controlling surface 11 and a projection 22 90 The driving member in the form of a gear wheel 16 is rotatably mounted on the hub of the arm 2 and is rotated by a drive (not shown) in the direction of the arrow in Figure 1 A closure plate 23 fixed on the shaft 1 by a screw 24 holds the arm 2 axially in posiS tion This plate also prevents axial displacement of the gear wheel 16

The felloe of the gear wheel is designated 20 In the circumference of the felloe are slots 15 which are equidistant and the cross-section of each of which viewed axially of the clutch diminishes towards its base The leading flanks 18 of the slots 15 are shallower than the trailing flanks 17 because there are provided in front of the slots inclined curved surfaces which extend gradually to the inner circumference of the felloe 20 The slot-engaging end of the detent 3 has a shape corresponding to that of the slots and is designated 13 in Figure 1. The clutch operates as follows: Initially the rail 8 is in the position shown by full lines in Figures 2 and 3 In this position, the end of the detent 3 is forced into engagement with one of the slots 15 in the fellce 20 of the gear wheel 16, by the action of the spring 7 On rotation, the gear wheel 16 carries with it the arm 2 and the shaft 1 If now the clutch is to be disengaged, the control rail 8 is brought into the position shown by broken lines in Figures 2 and 3 by means of the lever 12 As the arm 2 rotates, the stud 5 of the detent 3 contacts the control surface 11 of the rail 8 and slides along it, so that the detent 3 is pushed radially inwards against the action of the spring 7 The end 13 of the detent 3 is thereby withdrawn from the slot in the felloe 20, and so the coupling between the gear wheel 16 and the arm 2 and the shaft 1 is released The rail 8 and the controlling surface 11 are so arranged that the end 13 of the detent 3 is disengaged when the stud 5 is brought by the controlling surface 11 into the lower position, designated 21 in Figure 1 In this position, the stud 5, as shown at 21, is adjacent a projection 22 on the rail 8 The rotary movement of the parts driven through the coupling is therefore, on disconnection of the drive, stopped in a definitely fixed position determined by the position of the projection 22. In order to prevent rebound of the arrested masses, the rail 8 may be provided with a latch having an oblique end formation, which is lifted by the stud 5 (which in this case may be lengthened) and when the stud 5 engages the projection 22 on the rail 8, falls behind the stud For this purpose the arrangement is preferably such, that the detent 3 is moved back by the surface 11 on the rail 8 so far that the outer extremity of the end 13 is in alignment with the outer surface 14 of the arm 2. When it is desired to re-engage the clutch, the rail 8 is again moved by means of the lever 12 into the position shown in full lines. This frees the stud 5 of the detent 3, so that the latter is forced radially outwards by the action of the spring 7 and engages the first slot 15 in the gear wheel 16 which it meets. This engagement is facilitated by the inclined 70 or curved surfaces provided in front of the slots in the direction of rotation, so that engagement of the end 13 with a slot 15 is ensured even at high speeds

of rotation of the gear wheel 16, and the whole surface of con 75 tact between the end 13 of the detent 3 and the flank 17 of the relevant slot is immediately effective Owing to the wedge shape of the end 13 and the slots 15, the transmission is positive and free from play so that also 80 negative torques can be resisted by the coupling and an initial overrun of the driven parts is excluded. The substantial advantages of the clutch according to the invention are as follows 35 Due to the large number of slots 15 in the gear wheel 16, an extremely quick, almost immediate engagement of the clutch is possible As a result of the large diameter of the felloe 20 of the gear wheel 16, the detent 3 90 has to bear small forces only and its section can be correspondingly small By positioning the clutch in the gear wheel, the space normally required for a separately constructed clutch is saved By means of the oblique 95 surfaces provided before the slots, reliable engagement is ensured In an operating position, the two clutch members are almost immediately and positively connected with each other as a result of the wedge shaped 100 and play-free coupling surfaces.

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* GB784969 (A)

Description: GB784969 (A) ? 1957-10-23

Improvements in and relating to fountain brushes

Description of GB784969 (A)

PATENT SPECIFICATION 78 ' Date of Application and filing Complete Specification: Nov9, 1955 No Application made in United States of America on Feb 18, 1955.

Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 19, A 9, J. International Classification:-A 46 b. COMPLETE SPECIFICATION Improvements in and relating to Fountain Brushes We, DUPLI-COLOR PRODUCTS CO, INC, a Corporation organised and existing under the laws of the State of Illinois, United States of America, of 2440 South Michigan Avenue, Chicago, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to fountain brushes for use in applying paint, lacquers and other liquids to walls and the like and for covering scratches and marks on metal, wood or unfinished surfaces of other materials. The aim of the invention is to provide a removable cap for such brushes which locates the brush bristles in a sealed recess during periods of non-use, and which is so shaped that damage to the bristles cannot occur in applying or removing the cap. According to the invention, the cap comprises a tubular member closed at one end and formed with an elongated cylindrical skirt for aligning the cap on the nozzle, and is provided with a small well of reduced diameter near its closed end which snugly receives and shapes the brush bristles, the mouth of the well being outwardly-flared so as to guide the bristles smoothly into the well without bending them back and so as to form a wedge seal with the tapered end of the nozzle. Valved fountain brushes equipped with removable caps adapted to retract the valve and brush into its container are known The retraction of the brush into the container, however, frequently displaces contents of the containers to pump slugs of liquid through the nozzle into the cap When liquids such as quick-drying paints, lacquers, enamels and stains, or like fluids having highly volatile solvents, are stored in the container, this discharge may occur with some force if the vap frth ale fluids in the containers creates a super-atmospheric pressure As the valve is unseated by the cap, the interior of the cap provides a lower pressure zone or receptacle for the fluid These slugs can accumulate in the cap and a messy 50 nozzle or clogged cap may result. The present invention overcomes the disadvantage referred to above in that the cap receives the brush in its extended position beyond the nozzle in a brush-shaping recess 55 and is guided by the nozzle so that the brush cannot be damaged If desired, the valve of the fountain brush may be equipped with venting passages or the cap may partially depress the brush to join the contents of the 60 nozzle with the cap

recess No discharge of slugs of liquid into the cap can result because the brush depressing action is not sufficient to displace or pump liquid from the nozzle and does not occur until the brush 65 is seated in its small shaping recess which is just large enough to accommodate the brush and does not have a slug receiving zone of lower pressure than the fluid pressure in the nozzle 70 The caps provided in accordance with the present invention are preferably equipped with resiliently-deformable seal cups or liners which are impervious to the vapours of solvents and the like ingredients in the contents 75 of the fountain brush Suitable seal cups or liners can be formed of plastics such as Polyethylene, Nylon and the like The cup or liner material should not be softened or hardened by exposure to the contents of the 80 fountain brush and should always retain sufficient resiliency to create a back pressure seal. The seal cup equipped caps can be made to co-operate with the nozzle, the valve, and 85 the side wall of the fountain brush to provide a triple seal for the brush bristles In this arrangement, the bristles are isolated from the atmosphere as well as from the contents of the fountain brush If desired, 90 4,969 32100/55. 784,969 however, the bristles may remain in communication with the contents of the fountain brush The cap is preferably threaded on the nozzle to draw the seal up tightly against S the nozzle end The cap end does not bottom on the nozzle so the cup can always be tightly bottomed on the nozzle end. Three examples of fountain brushes incorporating the invention are shown in the accompanying drawings, in which: Fig 1 is a side elevation of a fountain brush (including cap) in accordance with the invention; Fig 2 is an enlarged longitudinal crosssection with parts in elevation and with parts broken away, taken on the line II-II in Fig. 1; Fig 3 is a view similar to Fig 2 but illustrating the manner in which the cap is guided on the nozzle; Fig 4 is a view similar to Fig 2 but illustrating a modified cap which partially depresses the brush; Fig 5 is a view similar to Fig 2 but illus-25 trating a modified valve and seat arrangement; and Fig 6 is a view taken on the line VI-VI in Fig 5. The fountain brush 10 shown in Figs 1 to 3 comprises an elongated, cylindrical barxrel 11 preferably composed of metal such as aluminium or zinc, a nozzle 12 projecting from one end of the barrel and preferably composed of a thermo-set plastic such as that -sold under the Registered Trade Mark "Bakelite," a valve and brush unit 13 arranged to slide in the nozzle, a guide washer 14, preferably composed of plastic, press fitted in the inner end of the nozzle -40 to hold the unit 13 in the nozzle, a spring 15 for urging the unit 13

downwards and a -heavy metal agitator ring 16 in the barrel 11 by means of which the contents of the barrel can be agitated. The nozzle 12 is closed by a relatively deep cap 17 preferably formed of thermoset plastic material such as Bakelite This cap carries an insert cup or liner 18 composed of resiliently deformable but relatively rigid material such as that sold under the Registered Trade Mark "Teflon," Nylon, or Polyethylene resins. The nozzle 12 has a cylindrical configuration with an enlarged head 12 a press-fitted into the open end of the barrel 11 A reduced diameter elongated cylindrical shank portion 12 b projects from the head 12 a beyond the end of the barrel and has a rounded tapered dispensing end 12 c Threads 12 d B O are formed externally on the nozzle shank 12 b adjacent the head 12 a A tapered valve seat 12 e is formed in the dispensing end of the nozzle and converges to a circular orifice 12 f in the centre of the nose 12 c. The head 12 a has an enlarged counterbore 12 g in which the plastic washer 14 is bottomed A cylindrical bore 12 i extends through the nozzle shank 12 b to the tapered valve seat 12 e. The brush unit 13 has a solid rod or shank 70 portion 13 a fitting freely through the aperture in the washer 14 and adapted to project into the aperture of the agitating ring 16 A head 13 b on the end of this shank or rod 13 a provides a shoulder 13 c adapted to seat on 75 the tapered valve seat 12 e A reduced diameter hollow portion 13 d projects from the shoulder 13 c freely through the orifice 12 f and carries a tuft of brush bristles to form a brush B which projects beyond the said ori 80 fice Lugs 13 e project radially at spaced intervals around the circumference of the head to form guides for the unit 13 by slidably engaging the bore 12 i whenever the unit is cocked 85 The spring 15 is bottomed on the lugs 13 e and head 13 b at one end, and at the other end Is bottomed on the washer 14 The spring surrounds the rod or shank portion 13 a and is effective to seat the valve on the 90 nozzle seat and to urge the brush beyond the end of the nozzle. Fluid from the barrel 11 is in full communication with the nozzle passage 12 i and is dispensed from this passage through the 95 orifice 12 f under the modulated control of the valve 13 c The bristles of the brush B are stiff enough to allow pressure on the end of the brush to unseat the valve and thus permit flow of liquid from the passage 12 i 100 to the brush bristles. The ring 16 is submerged in liquid, such as paint, in the barrel 11 and is adapted to be surged through the liquid to agitate it and mix the ingredients Since the ring 16 re 105 ceives the rod or shank 13 a when it reaches the end of its stroke at the head 12 a, the fluid in the barrel is subjected to a pump action which tends to force it into

the nozzle passage 12 i 110 The cap 17 comprises a tubular member closed at one enid and formed with an elongated cylindrical side wall or skirt 17 a defining a cylindrical bore 17 b of slightly larger diameter than the portion 12 b of the nozzle 115 so that the skirt freely embraces the nozzle. The open end of the cap preferably has a thickened reinforced portion 17 c which has internal screw-threads 17 d for threaded engagement with the screw-threads 12 d on the 120 nozzle The main side wall or skirt 17 a of the cap beyond the thickened portion 17 c is preferably fluted or grooved as shown at 17 e in Fig 1 to provide a hand grip for loosening or tightening the cap on the foun 125 tain brush. The closed end of the cap 17 f has a thickened side wall portion 17 o to reinforce the closed end This thickened portion 17, defines a reduced diameter bore 17 h in the 130 784,969 closed end of the cap joined with the bore 17 b by a tapered shoulder 17 i. The sealing liner 18 in the cap 17 has a cylindrical portion 18 a sized to be pressfitted in the bore 17 h together with an end head 18 b Mor bottoming on -the closed end of the cap The liner 18 has an enlarged head 18 c which is press-fitted in the bore 17 b and which bottoms on the shoulder 17 i The liner defines recess 18 d having an outwardlyfiared mouth or entrance 18 e The recess 18 d snugly receives the brush B so as to shape the brush bristles and maintain them in close associated relation to preserve a good painting end The mouth 18 e of the liner guides the brush bristles into the recess and also forms a seat for providing a wedge seal with the nose 12 c of the nozzle. As illustrated in Fig 3, when the cap 17 is applied to the nozzle 12, the skirt or wall 17 a of the cap slides over the nozzle portion 12 b to align the liner 18 with the brush B before the brush engages the liner The skirt 17 a is sufficiently long so that the cap is axially aligned on the nozzle before the brush bristles can be engaged by the liner. Thus, the distance between the open end of the cap and the top of thexecess 18 d exceeds the depth of the latter As the aligned cap is advanced to the screw-threads 12 d of the nozzle, the brush smoothly slides into the recess 18 d of the sealing cup while its bristles are gathered together by the flared mouth 18 e of the recess When the cap is threaded on to the nozzle, the brush bristles are 'surrounded by the smooth confining side wall of the recess 18 d and cannot be twisted or damaged However, if the bristles should stick to the side wall of the recess 12 d as the cap is rotated, the entire brush unit 13 can rotate with the liner so that the bristles will not be twisted. As illustrated in Fig 2, the liner head 18 c sealingly engages the rounded nose 12 c of the nozzle when the cap is tightly threaded on

the nozzle In this arrangement, the brush B is thereby isolated or sealed in the recess 18 d It is doubly sealed from communication with the atmosphere by the sealing engagement of the liner head and nozzle end and by the sealing engagement of the cap and nozzle threads In addition, the brush is sealed from the contents of the nozzle by the valve 13 c being seated on the valve seat 12 e Since the brush is not retracted into the nozzle by the cap and since the recess 18 d is just large enough to accommodate the brush and is sealed from the atmosphere, the heretofore encountered discharge of slugs of liquid accompanying the closing of fountain brushes having brushretracting caps is avoided, and the recess will not be filled with the contents of the container even if the valve is opened Any minute quantity of fluid which flows through an opened -valve is taken up by the brush to keep the liner relatively clean. In the 'modification shown in Fig A, the fountain brush -is equipped with a modified cap 1 i' ha Ving a modified seal liner 19 com 70 posed of the Qsame material as the liner 18 shown in Figs 1-3 A thick end wall 19 b is provided on the liner 19, and the recess 19 d is shallower than the recess 18 d of the liner 18 75 When the cap 17 ' is applied to the nozzle 12, it is -guided in the same manner as illustrated in Fig 3 but before the cap 171 is tightened on the nozzle, the end wall 19 b of the liner 19 abuts the end of the brush 13 to 80 retract the brush and open the valve 13-b. The valve is only slightly opened and the brush is slightly retracted when the cap is tightened on the nozzle In this arrangement, therefore, the contents of the container 85 are joined with the recess in the liner when the cap is seated on the nozzle so that the -brush is not isolated from the reservoir as in the fountain brush shown in Figs 1 to 3 This communication may sometimes be desirable 90 to keep the brush exposed to the solvents in the barrel 11 However, the partial retraction of the brush does not permit the heretofore encountered pumping action effected by complete retraction of the brush with the 95 cap. In the second modification shown in Figs. and 6, the fountain brush 101 is closed with a cap 17 which is identical to that shown in Figs 1 to 3 Although the cap 17 does not 100 retract the brush, the brush remains in communication with the contents of the nozzle when the cap seals the brush For this purpose, the tapered valve seat 12 e of the nozzle is provided with one or more grooves 20 and 105 the valve head 13 b is equipped with one or more notches 21 at spaced intervals around the periphery thereof at the valve shoulder 13 c Thus, even when the valve is closed, the passages provided by the grooves or 110 notches 20 and 21 connect the contents of the nozzle with the brush and the sealed brush in the liner 18

remain in communication with the fluids in the nozzle While the grooves 20 in the valve seat and notches 21 115 in the valve have been illustrated, it will be appreciated that either the grooves or the notches could be used alone. From the above description it will, therefore, be seen that the invention provides a 120 fountain brush having an improved cap or seal which isolates and shapes the brush and which is guided by the nozzle of the fountain brush so that the brush bristles cannot be damaged in applying the cap 125

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* GB784970 (A)

Description: GB784970 (A) ? 1957-10-23

Improvements in or relating to process for the production of a normallysolid, polymeric hydrocarbon material

Description of GB784970 (A)

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PATENT SPECIFICATION Inventors: EDMUND FIELD and MORRIS FELLER 7849970 -C Date of Application and filing Complete Specification: Dec 2, 1955. No 34578/55. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Classes 1 ( 1), A 31 81; and 2 ( 6), P 2 (A: DIA: FX: K 7), P 2 Pl(B: C: E 3), P 2 P( 3: 5: 6 A: 6 B: 6 X), P 2 T 2 (D: E), P 7 A, P 7 D(IA: 13:1 X: 2 A 1), P 7 FX, P 7 K( 2: 7: 10), P 7 P 1 (B: C: E 3), P 7 P( 3: 5: 6 A 613: 6 X), P 7 T 2 (D: E). International Classification:-B Olj CO 8 f. COMPLETE SPECIFICATION Improvements in or relating to process for the production of a Normally Solid, Polymeric Hydrocarbon Material We, STANDARID OIL COMPANY, a corporation organised under the laws of the State of Indiana, United States of America, of 910, South Michigan Avenue, Chicago, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to novel polymerization catalysts and to novel processes for their employment In a more specific aspect, this invention relates to novel catalysts and processes for the conversion of normally gaseous n-alkenes or mixtures thereof with each other or with other unsaturated materials, to produce normally solid products in the presence of certain reactive hydrogen compound and oxides of transition metals of Group 5 of the Periodic System (corresponding to oxides of metals selected from Group 5 a of the Mendeleef Periodic Table) The reactive hydrogen compounds are the hydrides of the alkali metals and/or the non-radioactive alkaline earth metals. One object of this invention is to provide novel and highly useful catalysts and catalyst promoters for the preparation of normally solid, high molecular weight polymers from gaseous feed stocks containing n-alkenes. Another object is to provide processes for the polymerization of normally gaseous n-alkenes at higher rates and in higher yields than those heretofore obtainable solely through the use of partially reduced metal oxides, specifically, partially reduced oxides of metals of Group 5 a of the Mendeleef Periodic Table An additional object is to provide novel low temperature, low pressure processes for the conversion of ethylene, propylene, 1-butene or their mixtures into high molecular weight, lPrice 3 s 6 d l waxy, resinous or rubbery

materials An additional object is to provide polymers of high density, greater stiffness and low water vapor permeability These and other objects of the invention will become apparent from the ensuing description thereof and a consideration of the annexed drawing. The present invention provides a process for the production of a normally solid hydrocarbon material, which comprises contacting a normally gaseous n-alkene under polymerization conditions with a reactive hydrogen compound from the class of alkali metal hydrides and non-radioactive alkaline earth metal hydrides, and with a solid catalyst comprising essentially an oxide or a salt of an oxyacid of a metal selected from Group Sa of the Mendeleef Periodic Table and separating the normally solid hydrocarbon material thus produced. Briefly, the inventive process comprises the conversion of a feed stock comprising essentially a normally gaseous n-alkene to high molecular weight, normally solid materials by contact with catalytic proportions of one or more of the oxides or salts of the oxyacids of metals selected from Group 5 a of the Mendeleef Periodic Table and one or more of the hydrides of the alkali metals and/or nonradioactive alkaline earth metals It is usually desirable to extend the Group 5 a metal oxide upon a support such as a difficultly reducible metal oxide and also to activate said oxide by partial reduction before use, for example, with various reducing gases such as hydrogen, dehydrogenatable hydrocarbons or carbon monoxide The selected polymerization temperature will depend upon the specific catalyst systems selected for use, namely, upon the metal oxide and reactive hydrogen compound. In general the selected polymerization temperature is usually between 75 C, and 325 "C, usually 110 C to 275 "C, and preferably 220-260 'C The polymerization can be effected even at atmospheric pressure, although usually the rate is low The polymerization pressure may extend to 15,000 or 20,000 p s i. (pounds per square inch) or even higher pressures but will usually be selected between and 5000 p s i g (pounds per square inch gauge), or, most often, at about 1000 p s i g. The normally solid materials produced by the catalystic conversion tend to accumulate upon and within the solid catalyst, so it is desirable to supply to the reaction zone a liquid medium which serves both as a reaction medium and a solvent for the solid reaction products Suitable liquid reaction media for polymerization include various hydrocarbons, particularly an aromatic hydrocarbon such as benzene, toluene or xylenes For the polymerization of propylene or 1-butene, less readily alkylatable reaction media such as cycloparaffins, e g, cyclohexane or decahydronaphthalene, or paraffins, e g, iso-octane, are preferred.

However, the conversion of the gaseous feed stock can be effected in the absence of a liquid reaction medium or solvent and the catalyst containing accumulated solid polymeric conversion products can be treated from time to time, within or outside the conversion zone, to effect removal of conversion products therefrom and, if necessary, reactivation or regeneration of the catalyst for further use. The inventive process is characterized by extreme flexibility both as regards operating conditions and as regards the products producible thereby Thus the present process can be effected over extremely broad ranges of temperature and pressure The practice of the present process can lead to grease-like homopolymers having an approximate molecular weight range of 300 to 700, wax-like homopolymers having an approximate specific viscosity ( x 105) between about 1000 and 10,000 and tough, resinous homopolymers having an approximate specific viscosity ( x 106) of 10,000 to more than 300,000 l(?i relative 1) x 10 'l By the term "tough, resinous polyethylene " as used herein, we mean polymer having a brittle point below 50 'C. (A.S T M Method D 746-51 T), impact strength greater than two foot pounds per inch of notch (A S T M Method D 256-47 T -Izod machine) and minimum elongation at room temperature ( 25 C) of 100 %. The process of the present invention can be employed to effect the copolymerization of normally gaseous n-alkenes with each other and/or with other polymerizable materials, such as iso-butylene, t-butylethylene, tetrafluoroethylene, styrene and butadiene In copolymerizations, the principal monomer is present in concentrations between about 75 % 1 O and about 95 % 1 O by weight, based on the weight of the total feed stock. The reactive metal hydrides employed in the inventive process have the general formula MH 1, wherein M represents an alkali metal or non-radioactive alkaline earth metal and N represents its valence The alkali metals are lithium, sodium, potassium, rubidium or caesium The alkaline earth metals are beryl 70 lium, magnesium, calcium, strontium and barium. The hydrides of calcium, strontium and barium are readily prepared by the interaction of hydrogen with the pure metals Thus 75 metallic calcium reacts readily with hydrogen at 200 'C to produce Ca 1- Calcium hydride can also be prepared by the reaction of Ca O with magnesium and hydrogen, which produced calcium hydride containing Mgo 80 Strontium hydride can be prepared by the reaction of a stronitum halide with lithium aluminum hydride (A E Finholt et al, J Am. Chem Soc 69, 1199-1203 ( 1947) Beryllium and magnesium hydrides can be prepared by 85 special methods known in the art The alkali metal hydrides can be prepared by the interaction of hydrogen with the pure metals and by other methods It will be understood that the specific

preparative methods involved form 90 no part of our invention and that any method which yields the desired metal hydride can be employed Usually the hydrides employed according to the present invention are prepared outside the reator, but they may be 95 prepared in situ and polymerization can then be effected in the reactor. The employment of one or more of the aforesaid hydrides in the reaction zone has numerous practical advantages, as compared 100 to processes wherein the metal oxide catalysts are employed without said hydrides Thus, when both the said hydrides and said metal oxide catalysts are employed, high yields of solid polymers can be obtained from ethylene, 105 the metal oxide-containing catalyst functions well in the presence of large proportions of liquid reaction medium, the metal oxide-containing catalyst retains strong polymerization activity for a long period of time (long cata 110 lyst life), and polymers having desirable ranges of physical and chemical properties can be readily produced by controlling the reaction variables, etc, as will appear from the detailed description and operating examples which 115 follow. The function or functions of the metal -hydrides in the process of the invention are not well understood The metal hydrides alone are not catalysts for the polymerization of 120 ethylene or propylene to yield high molecular weight, normally solid polymers under the conditions described herein Yet, the metal hydrides co-function somehow with the metal oxide catalyst to increase the productivity 125 (polymer yield) of said catalyst, sometimes prodigiously It might be assumed that the metal hydrides function merely to react with catalyst poisons which might be present in small proportions of the order of a few parts 130 784,970 are such that support is in major amount, e g. in the range of 1: 20 to 1: 1, or approximately 1: 10 We may employ conditioned aluminametal oxide catalysts composed of gammaalumina base containing about 1 to 80 %, pre 70 ferably 5 to 35 %, or approximately 10 %, of catalytic metal oxide supported thereon. Although no reducing treatment need be effected on the metal oxide catalysts when they are employed in the presence of reactive metal 75 hydrogen compounds, a reducing or conditioning treatment is preferred in commercial processing The conditioning or reducing treatment of the pentavalent Group 5 a metal oxide catalyst is preferably effected with hydrogen 80 although other reducing agents such as carbon monoxide, mixtures of hydrogen and carbon monoxide (water gas, synthesis gas, etc), sulfur dioxide, hydrogen sulfide or dehydrogenatable hydrocarbons may be employed Hydrogen can 35 be employed as a reducing agent at temperatures between about 350 'C and about 850 'C, although it is more often employed at temperatures within the range of 4500 C to 6500 C.

The hydrogen partial pressure in the reduction 90 or conditioning operation may be varied from sub-atmospheric pressures, for example even 0.1 pound (absolute), to relatively high pressures up to 3000 p s i g, or even more The simplest reducing operation may be effected 95 with hydrogen simply at about atmospheric pressure The partial reduction of the metal oxide catalyst in which the metal is present in its maximum valence state can be effected in the presence of the reactive metal hydrogen 100 compound, prior to contacting the combination of catalysts with the gaseous feed stock. Lithium aluminum hydride, an exceptionally active reducing agent, conditions and activates catalysts containing pentavalent Group 5 a 105 metal oxides even at temperatures as low as C, although in general temperatures between 100 and 300 'C are employed In practice, for example, a catalyst containing free or chemically combined V 0, or 110 (Co V 203) is treated with a suspension of Li Al H, in a hydrocarbon solvent at weight ratios of about 0 01 to about 1 Li A 1 H per weight of solid catalyst Sodium hydride (or sodium plus H) is effective in partially reduc 115 ing and conditioning Group 5 a metal oxide catalysts such as V 0, at temperatures above about 180 C and can be employed in the same proportions as Li Al H 1 Reactive metal borohydrides may likewise be employed to 120 effect partial prereduction of the Group 5 a metal oxide catalysts, employing essentially the same conditions as when Li Al H, is used. The conditioning treatment hereinabove described is useful not only for fresh catalyst, 125 but may also be desirable for catalyst which has become relatively inactive in the polymerization step As will be hereinafter described, the polymer formed in the polymerization reaction must be continuously or inter 130 per million in ethylene, propylene and/or in the liquid reaction medium; we have found, however, that even extremely pure ethylene or propylene and liquid reaction medium which have been contacted with alkali metal or with calcium hydride under reaction conditions and directly thereafter contacted in a separate zone with molybdenum oxide catalysts, do not produce solid polymer in the high yields or quality which can be attained by the process of the present invention. It was further discovered that the claimed metal hydrides so activate molybdena catalysts that solid polymers were obtained by contacting ethylene with Mo O, alone, i e, without a support which functions greatly to increase the surface area upon which Mo O, is extended. The Group 5 a metal oxides which are employed in preparing catalysts for this invention are the oxides of vanadium, niobium and tantalum The selected catalytic metal oxide or mixture thereof can be extended upon a variety of difficultly reducible metal oxides, for example upon alumina, titania or zirconia; upon silica supports such as silica gel,

kieselguhr or diatomite; upon synthetic silicaalumina preparations, upon naturally-occurring alumino-silicates, especially the montmorillonites, such as occur in various clays or bleaching earths; and even adsorptive carbon, which is however not preferred. Vanadia or other vanadium-oxygen compound, such as cobalt vanadate, may be incorporated in the catalyst base in any known manner, e g by impregnation, coprecipitation, co-gelling, and/or absorption, and the catalyst base and/or finished catalyst may be heatstabilized in the known manners heretofore employed in the preparation of hydroforming or hydrofining catalysts Cobalt, chromium, magnesium, calcium, zinc, nickel and copper salts of vanadic, niobic and tantalic acids may also be employed, with or without a support. The catalyst may be stabilized with silica or with aluminum ortho-phosphate or other known stabilizers or modifiers The catalyst may contain calcium oxide or the base may be in the form of a zinc aluminate spinel and it may contain appreciable amounts of zirconia or titania Oxides of other metals such as magnesium, nickel, zinc, vanadium, thorium and iron may be present in minor amounts, below 10 weight percent of the total catalyst. Gamma-alumina, titania and zirconia supports for our catalysts may be prepared in any known manner and the oxides of vanadium or other group 5 a metal may likewise be incorporated in, or deposited on, the base in any known manner. The relative proportions of support to the catalytic metal oxide are not critical and may be varied throughout a relatively wide range such that each component is present in amounts of at least approximately 1 weight percent The usual metal oxide-support ratios 784,970 mittently removed from the catalyst particles, preferably by means of solvents, and it is usually necessary or desirable to condition a catalyst surface which has been thus freed to some extent from polymer, before it is again employed for effecting polymerization When catalyst can no longer be rendered sufficiently active by simple removal of polymer and conditioning with a reducing gas as hereinabove described, it may be regenerated by extraction with water or dilute aqueous acids, thereafter burning combustible deposits therefrom with oxygen followed by the conditioning step. Detoxification of the catalysts by treatment with dilute aqueous solutions of per-acids such as permolybdic, pervanadic or pertungstic acids may be practiced, followed by hydrogen-conditioning of the catalysts. The proportion of alkali metal hydride may be varied between about 0 001 and about 2 parts by weight per part by weight of the metal oxide catalysts (total weight of solid catalyst), more often between 0 01 and 0 25.

The proportion of alkaline earth metal hydride to metal oxide catalysts (by weight) may be varied from about 0 01 to about 10, usually between 0 1 and 2 The optimum proportions can readily be determined in specific instances, by simple small-scale tests with the specific feed stocks, liquid reaction medium, reaction medium: catalyst ratio, catalyst, specific reactive metal hydrogen compound, temperature, pressure and nature of the product which is desired. The catalysts can be employed in various forms and sizes, e g, as powder, granules, microspheres, broken filter cake, lumps, or shaped pellets A convenient form in which the catalysts may be employed is as granules of about 20-100 mesh/inch size range Pellets or granules containing both the metal oxide catalyst and metal hydride may be prepared and used in our process Very finely-divided catalysts can be prepared by conventional methods such as grinding, or ball-milling. The alkene or co-monomer may contain hydrogen and extraneous hydrocarbons, as in refinery gas streams, for example, methane, ethane, propane, and butanes However, it is usually preferred to employ relatively concentrated alkene charging stocks When the charging stocks contain a plurality of normally gaseous n-alkenes, all may contribute to the production of resinous high molecular weight products. It is desirable to minimize or avoid the introduction of oxygen, carbon dioxide, water or sulfur compounds into contact with the catalysts. Polymerization can be effected in the presence of Group 5 a oxide catalysts and the reactive metal hydrides at temperatures between 750 C and 3250 C, usually at 1100 C. to 2750 C or in a preferred narrower range of 220 to 260 'C The conjoint use of polymerization temperatures between 220 and 260 C and a liquid hydrocarbon reaction medium such as benzene, xylenes, decahydronaphthalene or methyl decahydronaphthalenes, is highly desirable in producing ethylene poly 70 mers having specific viscosities ( x 103) ranging on the average from about 10,000 to about 30,000 when using continuous operations with relatively long on-stream periods and clean catalysts 75 It has been found that the present process can be employed for the production of relatively high molecular weight hetero and homopolymers of normally gaseous n-alkenes at relatively low pressures The process of the 80 present invention can be effected to some extent even at atmospheric pressure The upper limit of polymerization pressure is dictated by economic considerations and equipment limitations and may be 10,000 p s i g, 20,000 85 p.s i g, or even more A generally useful and economically desirable polymerization pressure range is between 200 and 5000 p s i g, preferably between 500 and 1500 p s i g, e g about 1000 p s i g 90

The contact time or space velocity employed in the polymerization process will be selected with reference to the other process variables, catalysts, the specific type of product desired and the extent of alkene conversion desired in 95 any given run or pass over the catalyst In general, this variable is readily adjustable to obtain the desired results In operations in which the alkene feed stock is caused to flow continuously into and out of contact with the 100 solid catalyst, suitable liquid hourly space velocities are usually selected between 0 1 and volumes, preferably 0 5 to 5 or about 2 volumes of alkene solution in a liquid reaction medium, which is usually an aromatic hydro 105 carbon such as benzene, xylenes, or tetrahydronaphthalene, or an alkane or a cyclo-aliphatic hydrocarbon, such as decahydronaphthalene. The amount of alkene in such solution may be in the range of 2 to 50 % by weight, prefer 110 ably 2 to 10 weight percent or, for example, to 10 weight percent It was observed that when ethylene concentration in the liquid reaction medium was reduced below about 2 weight per cent, the molecular weight and 115 melt viscosity of the polymeric products drops sharply The rate of ethylene polymerization tends to increase with increasing concentration of the ethylene in the liquid reaction medium. However, the rate of ethylene (or other alkene) 120 polymerization to form high molecular weight, normally solid polymers is preferably not such as to yield said solid polymers in quantities which substantially exceed the solubility thereof in said liquid reaction medium under 125 the reaction conditions, usually up to about 5-7 weight percent, exclusive of the amounts of polymeric products which are selectively adsorbed by the catalyst Although ethylene, or other alkene, concentrations above 10 130 784,970 784,970 5 weight percent in the liquid reaction medium may be used, solutions of polymer above 5% in the reaction medium become very viscous and difficult to handle and severe cracking or spalling of the solid metal oxide catalyst particles or fragments may occur, resulting in catalyst carry-over as fines with the solution of polymerization products and extensive loss of catalyst from the reactor. In batch operations, operating periods of between one-half and about 10 hours, usually between 1 and 4 hours, are employed and the reaction autoclave is recharged with alkene feed stock as the pressure falls as a result of the olefin conversion reaction. The solvent: catalyst weight ratio can be varied in the range of about 5 to about 3000, or even higher for flow systems The employment of high solvent: catalyst ratios, which is rendered possible by the presence of one or more of the hydrides of an alkali metal or alkaline earth metal in the reaction zone, is very important in obtaining high

yields of polymer. Normally gaseous n-alkenes can also be polymerized in the gas phase and in the absence of a liquid-reaction medium Upon completion of the desired polymerization reaction it is then possible to treat the solid catalyst for the recovery of the solid polymerization products, for example by extraction with suitable solvents However, in the interests of obtaining increased rates of alkene conversion and of continuously removing solid conversion products from the catalyst, it is much preferred to effect the conversion of the alkene in the presence of suitable liquid reaction media The liquid reaction medium may also be employed as a means of contacting the alkene with catalyst by preparing a solution of the alkene feed stock in the liquid reaction medium and contacting the resultant solution with the polymerization catalyst. The liquid reaction medium functions as a solvent to remove some of the normally solid product from the catalyst surface. Various classes of hydrocarbons or their mixtures which are liquid and substantially inert under the polymerization conditions of the present process can be employed Members of the aromatic hydrocarbon series, particularly the mononuclear aromatic hydrocarbons, viz, benzene, toluene, xylenes, mesitylene and xylene p-cymene mixtures can be employed. Tetrahydronaphthalene can also be employed In addition, one may employ such aromatic hydrocarbons as ethylbenzene, isopropylbenzene, sec butylbenzene, t butylbenzene, ethykltoluene, ethylxylenes, hemimellitene, psuedocumene, prehnitene, isodurene, diethylbenzenes,and isoamylbenzene. Suitable aromatic hyrocarbon fractions can be obtained by the selective extraction of aromatic naphthas, from hydro-forming operations as distillates or bottoms, and from cycle stock fractions of cracking operations. One may also employ certain alkyl naphthalenes which are liquid under the polymerization reaction conditions, for example, 1methyl-naphthalene, 2 isopropylnaphthalene, 70 and 1-n-amylnaphthalene, or commercially produced fractions containing these hydrocarbons. Certain classes of aliphatic hydrocarbons can also be employed as a liquid hydrocarbon re 75 action medium in the present process Thus, one may employ various saturated hydrocarbons (alkanes and cycloalkanes) which are liquid under the polymerization reaction conditions and which do not crack substantially 80 under the reaction condition Either pure alkanes or cycloalkanes or commercially available mixtures, freed of catalyst poisons, may be employed For example, one may employ straight run naphthas or kerosenes containing

85 alkanes and cycloalkanes Specifically, we may employ liquid or liquefied alkanes such as npentane, n-hexane, 2,3-dimethylbutane, noctane, iso-octane ( 2,2,4-trimethylpentane), ndecane, n-dodecane, cyclohexane, methylcyclo 90 hexane, dimethylcyclopentane, ethylcyclohexane, decahydronaphthalene, methyl decahydronaphthalenes and dimethyl decahydronaphthalenes. One may also employ a liquid hydrocarbon 95 reaction medium comprising liquid olefins, e.g, n-hexenes, cyclohexene, octenes, and hexadecenes. The normally solid polymerization products which are retained on the catalyst surface or 100 grease-like ethylene polymers may themselves function to some extent as a liquefied hydrocarbon reaction medium, but it is highly desirable to add a viscosity-reducing hydrocarbon such as those mentioned above, thereto 105 in the reaction zone. The liquid hydrocarbon reaction medium should be freed of poisons before use in the present invention by acid treatment, e g, with anhydrous p-toluenesulfonic acid, sulfuric acid, 110 or by equivalent treatments, for example with aluminum halides, or other Friedel-Crafts catalysts, maleic anhydride, calcium, calcium hydride, sodium or other alkali metals, alkali metal hydrides, lithium aluminum hydride, 115 hydrogen and hydrogenation catalysts (hydrofining), filtration through a column of copper grains or 8th group metal, or by combinations of such treatments. C.P xylenes have been purified by refluxing 120 with a mixture of 8 w% Mo O, on A 1,0, catalyst and Li AIH 4 1 ( 50 c c xylene-1 g Mo O,ALO 0-0 2 g Li Al H 4) at atmospheric pressure, followed by distillation of the xylenes Still more effective purification of solvent can be 125 achieved by heating it to about 225 -250 C. with either sodium and hydrogen or Na H in a pressure vessel. Temperature control during the course of the alkene conversion process can be readily accom 130 784,970 plished owing to the presence in the reaction zone of a large liquid mass having relatively high heat capacity The liquid hydrocarbon reaction medium can be cooled by heat exchange inside or outside the reaction zone. When solvents such as xylenes are employed some slight alkylation thereof by ethylene can occur under the reaction conditions Propylene is a far more reactive alkylating agent than ethylene and when propylene or 1-butene is present in the feed, it is desirable to employ a relatively non-alkylatable solvent such as decahydronaphthalene The alkylate is removed with grease in the present process, can be separated therefrom by fractional distillation and can, if desired, be returned to the polymerization zone. An illustrative flow diagram indicating one method by which the process of our invention may be effected is set forth in the accompanying drawing The alkene feed stock, e g, ethylene or an

ethylene-propylene mixture, is passed through compressor 10 wherein the pressure thereof is raised to a suitable value, for example, between 500 and 2000 pounds, thence into chamber 11, which is provided with a suitable deoxygenating agent such as metallic copper at 1500 C, then into chamber 12 which is provided with a dehydrating agent such as adsorptive alumina, anhydrous calcium sulfate, silica gel or equivalent drying reagent. The dried feed stock is passed from chamber 12 into chamber 13 wherein carbon dioxide is removed from the charging stock Chamber13 is provided with a suitable reagent, for example, sodium hydroxide deposited upon asbestos or with any other efficacious decarbonating reagent The feed stock thus purified usually contains less than 50 parts per million of oxygen and has a dew point below 450 C. The purified feed stock is then passed into an absorber 14, wherein it meets a counterflow of solvent Solvent or liquid reaction medium may be charged to the absorber and to the process by pump 15 through valved line 16 and heat exchanger 17, wherein it is brought to a suitable temperature for absorption, usually between 15 and 350 C although higher or lower temperatures can be used; recycle solvent from line 61 may also be charged to the absorber or may be the sole absorption medium employed In absorber 14 a solution containing between about 2 and about 30 percent alkene, e g about 7 weight percent ethylene, is produced and is withdrawn through valved line 18 into a guard chamber 19 for final purification The guard chamber may contain an active metal or metal hydride, for example, sodium or other alkali metal, an alkaline earth metal, an alkali metal hydride or an alkaline earth metal hydride The guard chamber may be filled with calcium hydride. The guard chamber may be operated at temperatures between 100 and 280 'C If the feed stock is of sufficient purity, the guard chamber may be by-passed (by lines not shown) and the feed stock introduced directly into reactor 25. From guard chamber 19 the ethylene and solvent are discharged into line 20, thence 70 through pump 21 into heater 22 wherein they are brought to the polymerization temperature, for example, between 200 and 2750 C. From heater 22 the charge is passed through line 23, thence through line 24 into the lower 75 end of reaction chamber 25 While a variety of suitable reactors can be employed, in the accompanying Figure there is illustrated an autoclave divided into upper and lower sections by baffle 26 A stirring mechanism 27 projects 80 into the lower portion of the reactor and suitable baffles 28 are provided at the walls The stirring mechanism may be operated at 20 to 1000 r p m (revolutions per minute), e g, about 650 r p m It will be apparent, there 85 fore,

that a high degree of intermixing between the catalyst, metal hydride, alkene and liquid reaction medium is achieved in the lower portion of reactor 25 Reactor 25 may be initially charged with the group 6 a metal oxide cata 90 lyst and metal hydride through lock hopper devices or equivalents, and further amounts of metal oxide catalyst and metal hydride can be added intermittently during the course of the reaction, as desired, by suitable means 95 If desired, a portion of the predried solvent can be passed through valved line 29 and heater 30, wherein it is brought to a temperature between about 150 and about 300 C, into a contacting chamber 31 provided with 100 baffle 32, stirring mechanism 33 and an inlet 34 for metal hydride An intimate dispersion of metal hydride in solvent is formed in contactor 31 and is withdrawn from the upper quiescent zone of contactor 31 (or from the 105 lower portion of contactor 31 through valved line 35 a), thence through valved line 35 into line 24, and is forced by pump 36 into reactor An alternative and very useful method of purifying the solvent in contacting chamber 11 C 31 is to treat said solvent with an alkali metal hydride, usually Na H, and a supported group 6 a metal oxide, e g 10 weight percent Mo O,gamma alumina, using about 3 to about 10 parts by weight of supported metal oxide per 115 part by weight of alkali metal hydride, at a temperature between about 135 and about 270 'C and liquid hourly space velocities between about 0 5 and about 10. In reactor 25, the polymerization of ethylene 120 or other alkene feed stock, or copolymerization of mixed alkenes, is effected at suitable temperatures and pressures The usual concentration of ethylene or other alkene in the solvent entering the reactor is about 10 weight 125 percent and the effluent from the reactor is usually a 2-5 weight percent solution of solid polymer in the solvent When the preparation of a homopolymer of ethylene having a Staudinger specific viscosity ( v 10 ') of about 130 784,970 The solution of polymer products is withdrawn from filter 42 through line 44 into cooler 45, wherein its temperature is adjusted to a value between about 90 and about 20 WC. and is then discharged through line 46 into 70 filter 47 The solid polymer product is removed from filter 47 through 48 and the solvent or reaction medium is withdrawn through line 49, whence a portion can be discharged from the system through valved line 75 50, a portion can be passed through valved line 51, pump 52 and heater 53 into separator 39, and the remainder can be passed through valved line 54 into fractionator 55. Precipitation of the polymer from the solu 80 tion from line 44 can be induced by the addition of anti-solvents such as low boiling alcohols or ketones (acetone) The polymeric product of the present process removed at 48 can be subjected to various treatments to prepare 85 it for conversion to a finished industrial product Thus, it may be

subjected to various treatments to remove the imbibed solvent, it may be shredded or extruded to form stringlike particles, or it may be dried 90 In fractionator 55, the solvent or liquid reaction medium is vaporized and passes overhead through line 56, whence a portion may be removed from the system through valved line 57, but is preferably passed through valved 95 line 58 into cooler 59, wherein its temperature is brought to a value between about 20 and about 80 C, whence it is passed into pump 60 Pump 60 forces the solvent through valved line 61 and heat exchanger 17 into 100 absorber 14 to prepare a solution of fresh alkene feed stock for the polymerization process A portion of the solvent is also forced by pump 60 through valved line 62 into the upper portion of absorber 63 Recycled gases 105 from separator 39 and line 40 are passed through valved line 64 and compressor 65 through line 66 into the lower portion of absorber 63, in which alkene is selectively absorbed in the solvent to produce a solution 110 having a concentration between about 2 and about 10 weight percent of alkene, which is discharged from absorber 63 through valved line 67 into line 20, whence it is passed to reactor 25 Unabsorbed gases are discharged 115 from absorber 63 through valved line 68. Liquid reaction products boiling above the boiling range of the solvent medium can be discharged from fractionator 55 and the process through valved line 69 but are preferably 120 passed through valved line 70 into a second fractionator 71 A by-product of the present polymerization process produced in relatively small volume when an alkylatable aromatic hydrocarbon solvent such as a xylene is em 125 ployed, is an alkylate formed by reaction of said alkylatable aromatic hydrocarbon and alkene The alkylated aromatic hydrocarbon products are vaporized and fractionated in tower 71, from which they are discharged 130 15,000 to 30,000 melt viscosity of 2 x 105 to about 5 x 106 poises is desired, the preferred temperatures are between 230 CC and 275 GC. The reaction period can be varied between about 10 and about 100 minutes. It will be understood that instead of one reactor, a number of reactors in parallel or in series can be used When reactors are employed in series, variations in temperature and pressure, alkene concentration in solvent, and catalyst concentration become possible so that more control can be exerted over the average molecular weight and molecular weight range of the product, as well as of the extent of conversion in each stage Also, through the employment of a number of manifolded reactors, suitable by-pass lines and valves, it becomes possible to cut any reactor out of the system for purposes of cleaning and repair. The upper portion of reactor 25 constitutes a quiescent settling zone

wherein fine catalyst particles and metal hydride settle from the solution of polymer product in the reaction solvent and return under the force of gravity to the lower agitated portion of the reactor. The relatively clear solution of reaction products in solvent is withdrawn from the upper portion of reactor 25 through line 37 and expansion valve 38, wherein the pressure is allowed to fall to a value between about 15 and about 250 p s i g The product mixture discharged from valve 38 tangentially into a separator, e g, a cyclone-type separator 39 wherein a temperature of at least about 150 'C. is maintained Gas comprising a substantial proportion of ethylene and/or other alkene feed stock in a poison-free condition is discharged from separator 39 through valved line Hot solvent may be introduced into separator 39 through line 51 in order to prevent separation of polymer upon the walls of the separator. In one preferred mode of operation, clear effluent from reactor 25 is bled through valve 38 down to the vapour pressure of the solvent, while maintaining the temperature in separator 39 at about 200 'C In this method of -operation, essentially all the ethylene and a substantial proportion of the benzene are removed from the effluent of reactor 25 and can be recycled (by lines and a pump not shown) to said reactor The relatively concentrated polymer solution can be treated as described hereinafter. The solution of polymer in solvent (maximum of about 5 weight percent polymer) is withdrawn from separator 39 through valved line 41, into filter 42, wherein any fine catalyst particles which may have been carried along, are separated and withdrawn through valved line 43 If desired, the polymer solution may be subjected to the action of ultrasonic vibrators, which may effect coagulation of the very fine catalyst particles so that they can be more readily filtered. 784,970 through line 72 It is usually desirable to recycle at least a portion of the alkylate through valved line 73 to line 41 for employment as a diluent and solvent in filter 42 The remainder of the alkylate may be discharged from the process through valved line 74 or may be recycled for employment as part of the liquid reaction medium in reactor 25. Relatively small proportions of low molecular weight grease-like olefin polymers are produced in the polymerization process The grease-like products are removed as a bottoms fraction from tower 71 through valved line 75. An alternative method of operation following filtration of fine catalyst particles in filter 42 involves introduction of the dilute solution of polymers in the reaction solvent, e g. benzene, into a tower containing hot water or a mixture of liquid water and steam at a temperature sufficient to flash distil the

solvent (or an azeotrope of solvent and water) from the solution and to produce a water slurry of the solid polymer containing about 1 to about S weight percent polymer The aqueous slurry of polymer can be concentrated by conventional methods to yield a slurry containing about 10 to 15 weight percent polymer, which can thereafter be centrifuged to yield a polymer containing a minor proportion of water, which can be thoroughly dried in conventional equipment The solvent passing overhead in the flash distillation operation can be condensed, separated from a lower liquid layer of water, redistilled to further dry it and finally can be thoroughly dried with desiccants, e g. silica gel or alumina gel, prior to recycle to storage or to the polymerization reaction zone. Another alternative is to spray-dry the solution of polymer in solvent from which catalyst fines have been removed. In the Examples, by the term " specific viscosity" we mean lrelative viscosity -1 l x 105 and by " relative viscosity" we mean the ratio of the time of efflux of a solution of 0 125 g polymer in 100 cc of C P xylenes at 110 'C from a viscosimeter as compared with the time of efflux of 100 cc of C P. xylenes at 1100 C The melt viscosity is-determined by the method of Dienes and Klemm, J Appl Phys 17, 458-71 ( 1946). The following are non-limitative examples of the invention and the first group ( 1 to 4) illustrate the results obtained with group 5 aalkali metal hydride catalysts The polymerization reactions were carried out in a 250 ml, vigorously agitated, bomb-type reactor. EXAMPLE 1 The reactor was charged under a blanket of hydrogen gas with 100 cc of purified toluene, 0 3 g of lithium hydride and 1 g of 10 weight percent V 0, supported upon silica gel, 30 to mesh per inch, which was prereduced before use with hydrogen at 350 'C and atmospheric pressure for 16 hours The reactor contents were heated with stirring to 230 'C. and ethylene was then pressured into the reaction mixture to an initial partial pressure of 670 p s i Ethylene was repressured into the reactor from time to time as it was consumed. Reaction was continued for 44 5 hours, result 70 ing in a total ethylene pressure drop of 620 p.s i The operation yielded 8 1 g per g of vanadia-silica catalyst of a tough, solid ethylene polymer having a density ( 24/4 C) of 0 9590, Williams plasticity of 30 2 and melt viscosity 75 of 8 x 10 ' poises (method of Dienes and Klemm, J Appl Phys 17, 458-71 ( 1946)). The reaction also yielded 3 7 g per g of catalyst of solid grease-like polyethylenes and some alkvlated toluene 80 When the vanadia-silica catalyst was employed without any promoter, no solid ethylene polymer could be obtained, as shown by the following experiment The autoclave

was charged with 10 g of 10 weight percent V 0, 85 supported on silica gel, about 40 to 100 mesh per inch, prereduced with hydrogen at 350 'C. and atmospheric pressure for 16 hours The reactor was also charged with 100 cc of dehydrated and decarbonated toluene The 90 charging operations were performed under a hydrogen blanket The contents of the reactor were then heated with stirring to 2320 C and ethylene was then introduced to an initial pressure of 775 p s i The reactor contents were 95 stirred for 20 5 hours This reaction yielded no solid ethylene polymer; only 4 g of a colored liquid were obtained. As a further control test, a vanadia-alumina catalyst was employed in the absence of a 100 promoter, as shown in the following experiment The reactor was charged with 10 g of weight percent V 0, supported upon a gamma-alumina, prereduced with hydrogen at 350 WC in the same manner as the aforemen 105 tioned vanadia-silica catalysts The reactor was charged with 50 cc of dehydrated and decarbonated toluene and the contents were heated with stirring to 2020 C Ethylene was then introduced into the reactor to a partial 110 pressure of -850 p s i and stirring was continued for 22 hours This reaction yielded only a trace amount of solid ethylene polymer. EXAMPLE 2 The reactor was charged under a blanket of 115 hydrogen gas with 100 cc of benzene which had been dried over sodium, 0 2 g of sodium hydride and 1 g vanadia-silica catalyst prepared as in Example 1 The contents of the reactor were heated with stirring to 230 WC 120 and ethylene was then pressured into the reactor to an initial partial pressure of 510 p s i. Reaction was continued for 57 hours, ethylene being pressured into the reactor intermittently as it was consumed The total ethylene pres 125 sure drop was 240 p s i The operation resulted in the production of 2 40 g per g of vanadiasilica catalyst of solid polyethylenes having a density ( 24/40 C) of 0 9586, Williams plasticity of about 17 and melt viscosity of about 130 784,970 spheric pressure The reactor contents were heated at 204 C under a blanket of hydrogen and ethylene was then introduced to a partial pressure of about 850 p s i Over the course of the 19 5-hour reaction period, the temperature was raised to 232 C The total yield of ethylene polymer obtained in the reaction was 2.12 grams per gram of catalyst. EXAMPLE 7 Similarly, it was noted that a solid ethylene polymer was produced by the contact of ethylene at 890 p s i for 150 minutes at 252 C with 50 cc of purified xylenes, 1 g. calcium hydride and 5 g of prereduced 10 weight percent Ta 0, supported upon gammaalumina The tantalum oxide catalyst was reduced

with hydrogen at 550 C at atmospheric pressure for 16 hours An ethylene pressure drop of 770 lbs was observed over the course of 150 minutes. EXAMPLE 8 The procedure of Example 5 was repeated but an equal weight of barium hydride was substituted for calcium hydride in the reactor charge The solid ethylene polymer was separated and worked up as before. EXAMPLE 9 The procedure of Example 6 was repeated but an equal weight of strontium hydride was substituted for calicum hydride and the solid ethylene polymer was separated and worked up as before. poises The reaction also yielded 1 5 g. per g of catalyst of solid grease-like polyethylenes and some alkylated benzene. EXAMPLE 3 The process of Example 1 was repeated but potassium hydride was substituted in onetenth part by weight for the lithium hydride of Example 1 and the vanadia-silica catalyst was replaced by an equal weight of 10 weight percent of Nbz O, supported upon an activated alumina, prereduced by the same technique as the vanadia-silica catalyst The reaction products were worked up to separate solid polyethylenes. EXAMPLE 4 The reactor was charged under a blanket of hydrogen gas with 100 cc of decahydronaphthalene which had been purified by treatment with silica gel, 0 5 g of sodium hydride and 5 g of 10 weight percent of Ta 2 O, supported upon gamma-alumina, 30 mesh per inch, which was prereduced with hydrogen at atmospheric pressure for about 16 hours at 550 C The contents of the reactor were heated with stirring in the presence of hydrogen to 299 C and ethylene was then pressured into the reactor to an initial partial pressure of 975 p s i Reaction was continued for 20 hours to yield 2 8 g per g of tantala-alumina catalyst of solid polyethylenes A decahydronaphthalene alkylate was also produced in the yield of about 0 24 g per g of catalyst. The following set of Examples ( 5 to 11) illustrate the results obtained with group 5 aalkaline earth metal hydride catalysts. EXAMPLE 5 The reactor was a 250 c c stainless steel pressure vessel provided with a magnetically-. actuated stirring device which was reciprocated within the reaction zone The catalyst was w % V O, supported upon gammaalumina, 30-100 mesh per mil, prereduced before use with hydrogen at 350 C and atmospheric pressure for 16 hours The reactor was charged with 100 c c of dehydrated and deoxygenated xylenes, 5 g of the prereduced vanadia

catalyst and 2 g of calcium hydride, while excluding air After pressure testing the reactor with hydrogen, the contents were heated to 260 C and then pressured with ethylene to 820 p s i An ethylene pressure drop of about 405 p s i was noted in 8 5 hours. The reaction yielded 91 weight percent, based on the weight of the vanadia catalyst, of a solid polymer having a specific viscosity of 16,600, melt viscosity of 1 9 x 10 ' and density of 0 9852 ( 24 C), together with 6 weight percent of grease-like ethylene polymer and 17 weight percent of xylenes alkylate. EXAMPLE 6 The 250 cc reactor was charged with 100 cc of purified toluene, 1 g of calcium hydride and 2 g of 10 % Nb O, supported on silica gel which was prereduced with molecular hydrogen for 16 hours at 400 C and atmoEXAMPLE 10 The procedure of Example 5 was repeated but an equal weight of magnesium hydride was 100 substituted for calcium hydride to produce a solid ethylene polymer. EXAMPLE 11 The procedure of Example 7 was repeated but beryllium hydride was substituted in equal 105 weight for calcium hydride to produce a solid ethylene polymer. When a group 2 metal hydride is employed alone under reaction conditions which yield solid ethylene polymers by the process of the 110 present invention, no solid polyethylene can be produced Thus no ethylene pressure drop was observed, nor any solid polyethylene produced in an attempted reaction in which the reactor was charged with 50 cc of purified toluene, 115 2 grams of calcium hydride and 300 p s i. ethylene (at 25 C) and the mixture was heated with stirring to 3550 C. The normally solid polymers produced by the process of this invention can be subjected 120 to such after-treatment as may be desired, to fit them for particular uses or to impart desired properties Thus, the polymers can be extruded, mechanically milled, filmed or cast, or converted to sponges or latics Antioxidants, 125 stabilizers, fillers, extenders, plasticizers, pigments, insecticides, fungicides, etc can be incorporated in the polyethylenes and/or in byproduct alkylates or "greases " The normally solid polymers may be employed as coating 130 784,970 materials, gas barriers, or binders. The normally solid polymers produced by the process of the present invention, especially the polymers having high specific viscosities, can be blended with the lower molecular weight polyethylenes to impart stiffness or flexibility or other desired properties thereto. The solid resinous products produced by the process of the present invention can, likewise, be blended in any desired proportions with

hydrocarbon oils, waxes such as paraffin or petrolatum waxes, with ester waxes, with high molecular weight polybutylenes, and with other organic materials Small proportions betwveen about 0 01 and about 1 percent of the various polymers produced by tile process of the present invention can be dissolved or dispersed in hydrocarbon lubricating oils to increase V I. and to decrease oil consumption when the compounded oils are employed in motors; larger amounts of the polymer products may be compounded with oils of various kinds and for various purposes. The products having a molecular weight of 50,000 or more produced by the present invention can be employed in small proportions to substantially increase the viscosity of fluent liquid hydrocarbon oils and as gelling agents for such oils The solution of about 1 gram of an ethylene polymer produced by this invention, having a specific viscosity x 105 of about 50,000 in about one liter of xylenes at a temperature close to the boiling point produced an extremely viscous solution. The normally solid polymers produced by the present process can be subjected to chemical modifying treatments, such as halogenation, halogenation followed by dehalogenation, suifohalogenation, e g, by treatment with sulfuryl chloride or mixtures of chlorine and sulfur dioxide, sulfonation, and other reactions to which hydrocarbons may be subjected.

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* GB784971 (A)

Description: GB784971 (A) ? 1957-10-23

Shaft positioning device

Description of GB784971 (A)

PATENT SPECIFICATION Inventor: HORST M SCHWEIGHOFER 7 t Date of application and filing Complete Specification: Jan 24, 1956. No 2364/156. Complete Specification Published: Oct23, 1957. Index at acceptance:-Class 80 ( 2), C 1 A( 7 C: 11 A), P(IJIA: 1 J 3 B: X). International Classification:-FO 6 d. COMPLETE SPECIFICATION Shaft Positioning Device We, COLLINS RADIO COMPANY, a Corporation of the State of Iowa, United States of America, of Cedar Rapids, Iowa, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates in general to shaft positioning mechanisms and in particular to apparatus wherein a relay controls a clutch to lock and unlock respectively, a toothedstop wheel. Many times, in the engineering field, it is desirable to control a shaft so that it will repeatedly stop at any one of a number of preset positions. It is an object of this invention, therefore to provide a shaft positioning means which will remember a plurality of preset positions. A further object of this invention is to provide a shaft positioning mechanism which is positive in operation and has great accuracy. The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 illustrates the shaft control mechanism of this apparatus with its related control circuit; Figure 2 is an exploded view of the shaft positioning mechanism of this invention; Figure 3 is a sectional view of the shaft positioning mechanism illustrating it in the engaged position; and, Figure 4 is a half-section view illustrating the clutch in the disengaged position. Figure 1 illustrates a plate 10 which has a standoff 11 mounted at each corner thereof that are attached to a second plate 12 A shaft 13 extends through the plates 10 and 12 and is rotatably supported therein One end of the shaft 13 is connected to a controlled element designated generally as 14, which might for example, comprise a condenser lPrice 3 s 6 d l which has its rotor plates 16 connected to the shaft 13 The stator plates may be suitably supported adjacent the rotor plates. As best shown in Figure 2, mounted to 50 the inner face of plate 10 is a toothed stopwheel 18 which has gaps formed in its extending portion An annular armature clutch member 19 is slidable but non-rotatably

supported on the shaft 13, as for ex 5, ample, by inserting a key 20 into key-ways 21 and 22. A pair of projections 33 extend longitudinally from the member 19 and are of a size such that they may be received in the teeth 60 of the stop wheel 18 The opposite side of the member 19 has a clutch face 24 which might be serrated or covered with a suitable friction material. An annular coil designated generally as 65 26, is mounted between the plates 10 and 12 and is attached to the standoffs 11 by the extending tabs 27 The inner diameter of the coil 26 is such that the clutch portion 24 may move therethrough O Rotably supported on the shaft 13 between the member 19 and the plate 12 is a second clutch member 28 This member is rotatably but non-slidably supported on the shaft 13. A pair of washers 29 and 31, best shown in 75 Figure 3, prevent it from moving longitudinally of the shaft It has a clutch face 32 which may be serrated or have a friction material attached thereto and is engageable with the portion 24 of the first clutch mem 8 g ber 19 Teeth are formed about the circumference of the member 28 for a purpose to be later described A spring 34 is mounted about the shaft 13 and biases the members 19 and 28 apart 85 A driving gear 36 is mounted on a shaft 37 which is rotatably supported by the plate 12 and is geared or directly coupled to a suitable driving means, as for example, an electric motor 38 90 The plate 10 has an opening 39 formed therethrough adjacent the opening 41 34.971 through which the shaft 13 passes and a pin 42 extends therethrough One end of the pin 42 is engageable with the surface of the member 19 and the other end is engageable with a switch contact 43 which forms a part of a switch designated generally as 44. The switch 44 is attached to the plate 10 and has, as best shown in Figure 3, a second contact 46 that is engageable with contact 43 As shown in Figure 1, contact 43 is electrically connected to ground and contact 46 is connected to one terminal of the motor 38. The other terminal of the motor 38 is connected to one side of a suitable voltage source, as for example, 28 volts d c The other side of the voltage source may be connected to ground When the switch 44 is closed, the motor will run thus driving the second clutch wheel 28. The annular coil 26 comprises a "U" shaped cover member 47 which is best shown in the sectional views of Figures 3 and 4, and a plurality of turns of wire 48 mounted therein The clutch members 19 and 28 are made of a suitable magnetic material so that when current passes through the coils 48 they will be attracted together against the tension of the spring so that the clutch will be engaged Since the member 19 is slideably, but non-rotatably supported on the shaft 13, whereas the shaft 13 is rotatably connected to the member 28, the motor 38 will drive the shaft 13 when the coil is energised When the

coil is de-energised the clutch faces 24 and 32 will be disengaged and the projections 23 will drop in a slot in the stop wheel 18, thus locking the controlled shaft 13. Thus, by controlling the current supplied to the leads 49 and 50 of the coil 48, the position of shaft 13 may be controlled The lead 50 is connected to the positive side of the voltage source which supplies the motor 38 Lead 49 is connected to a contact 51 engageable with a conducting disc 52 of a wafer switch A plurality of contacts 53 are mounted about the disc 52 with a number of short wiper contacts 54 connected to each A gap 56 is formed in the disc 52 and is of a SO size such that it extends approximately the distance between adjacent contacts 54. A remote control switch designated generally as 57 has a wiper contact 58 that is engageable with a plurality of terminals 59 SS mounted about its perifery The terminals 59 are connected respectively to the terminals 53 The wiper contact 58 is grounded and is mechanically connected by shaft 61 to a control knob 62 It is to be realised, of course, that the knob 62 and the control switch 57 may be located at any remote position. The switches thus shown may be used to position the shaft 13 to any number of positions equal to the number of terminals 59. Thus, for example as shown in Figure 1, twelve positions of the shaft 13 may be obtained This number corresponds to the number of teeth in the stop-wheel 18. It is to be realised, of course, that there are 70 a number of different circuits that may be used for actuating this mechanism and reference may be made to our Patent Specification No 660,939 for other circuits. In operation let it be assumed that it is de 75 sired to move the controlled element comprising the rotor plates 16 of the condenser to a new position The knob 62 is turned, as for example, to position 3 This mechanically moves the wiper contact 58 to ter 80 minal 3 on switch 57 which closes the circuit to the relay coil 48 This may be seen by tracing the coil circuit from ground through the wiper contact 58, the terminal 3 of switch 57 to the terminal 3 of disc 52, the 85 contact 51 to the coil 48 and to the positive side of the voltage source Thus, the coil will be energised and the clutch plate 19 will be moved longitudinally of the shaft 13 moving the projections 23 out of engagement 90 with the teeth of the stop-wheel 18 The pin 42 will then move to the right with reference to Figure 2 This closes the contacts to switch 44 This causes the motor 38 to start thereby driving shaft 13 and disc 52 until 95 the gap 56 is adjacent the contact 54 connected to terminal 3 When this occurs, the circuit to the coil 48 will be opened and the spring 34 will force the clutch

plates apart so that the projections 23 fall into a groove 100 in the stop-wheel 18 This opens the switch 44 and disconnects the motor. It is seen that this invention comprises a new and novel means of controlling the position of a shaft to any one of a plurality of 105 positions. Although this invention has been described with respect to particular embodiments thereof, it is not to be so limited as changes and modifications may be made therein 110 which are within the full intended scope of the invention as defined by the appended claims.

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* GB784972 (A)

Description: GB784972 (A) ? 1957-10-23

Method and apparatus for bending glass sheets or plates

Description of GB784972 (A)

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PATENT SPECIFICATION Date of Application and filing Complete Specification: Jan 25, 1956. 784,972 No 2420156. i' 'i p j| Application made in United States of America on Feb 3, 1955. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 56, M F 3. International Classification:-CO 3 b. COMPLETE SPECIFICATION Method and Apparatus for Bending Glass Sheets or Plates We, Li BBEY-OWENS-Fo RD GLASS COMPANY, a Corporation organized under the Laws of the State of Ohio, of 608 Madison Avenue, City of Toledo, County of Lucas and State of Ohio, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention is generally concerned with the bending of glass sheets or plates, and more particularly with an improved method and apparatus for bending glass sheets of substantial length. The automobile windshields now in common use, such as the panoramic or hooktype windshields, require the use of flat glass sheets of increased length as compared to prior windshields of relatively shallow curvature This is equally true with respect to automobile back windows which now are usually of one-piece construction and have 2 extensively curved end portions The molds commonly used in bending these windshields, and back windows, have a concavely curved shaping surface, and the flat glass sheet to be bent is initially supported at its opposite ends above the shaping surface by suitable supporting means associated with the mold The mold and sheet are then passed through a furnace in which the sheet is subjected to a temperature such as to cause the glass to soften and bend downwardly into conformity with the shaping surface. During the bending of the sheet, the supporting means exerts pressure upon the opposite ends of the sheet to accelerate the bending. As the length of the flat sheet to be bent increases, this method of supporting the sheet at its opposite ends upon a concave mold and exerting pressure thereon creates a problem due to the increase in the deflection of the central portion of the sheet Such an increase in the amount of deflection is unl Ne 3 Ll desirable since the central portion of the sheet, when passed through a bending furnace, may contact the shaping surface of the mold before those portions of the sheet outwardly of the central portion are at the 50 proper temperature to conform to their respective portions of the shaping

surface. Moreover, there is always a slight deflection in the center of the flat sheet when it is initially supported on the mold due to its normal 55 tendency to act as a beam Therefore, any force applied to the ends of the sheet will increase the amount of deflection since the central portion of the sheet is eccentric to the applied force Also, as the distance be 60 tween the supports for the sheet increases, due to longer sheet lengths, the bending moment developed in the center of the sheet increases, and if the length of the sheet is such that the supports are at a distance suffi 65 cient to cause this bending moment to reach a critical value, the glass sheet may break or shatter. Bending molds which tend to eliminate some of the above-mentioned problems are 70 those of the convex type wherein the shaping surface {is convexly curved and the glass sheet is supported thereon substantially at its central portion However, the use of convex molds, in bending automobile wind 75 shields or rear windows, has produced at least one undesirable feature in the glass sheets bent thereon Namely, the sheet has a "caved-in" appearance when installed in an automobile Thins is produced during 80 bending and is caused by the portions of the sheet, inwardly of the mold shaping surface, sagging downwardly After being bent and mounted in an automobile, a sheet which is bent on a convex mold has its upper surface 85 disposed to the outside and, therefore, has the afore-mentioned undesirable visual defect. On the other hand, concave molds which produce an arched effect in the bent glass 90 Wict 46 64 784,972 sheet, when installed in an automobile, are not entirely satisfactory in bending sheets of substantial length because of the aforementioned problems involving deflection, etc. Therefore, an important object of the present invention is to provide an improved method and apparatus for bending glass sheets of substantial length and particularly those having sharply curved end portions. Another object of the invention is to provide a method and apparatus for bending glass sheets in which advantage is taken of the better features of both convex and concave bending molds. A further object of the invention is to provide a method of bending glass sheets in which the sheet is initially bent on a mold having a convex shaping surface, and then shaped to its finished curvature upon a mold having a concave shaping surface. A still further object of the invention is to provide a method of bending glass wherein the sheet is initially bent on a convex shaping surface, then has its upper surface engaged by a concave shaping surface, inverted while retained between the two shaping surfaces, and then bent to final curvature while retained on the concave shaping

surface. In the accompanying drawings:Fig 1 is a side elevation view of a convex mold having a glass sheet to be bent supported thereon; Fig 2 is a plan view of the mold shown in Fig 1; Fig 3 is a side elevation view of the convex mold after the glass sheet has been bent thereon and with a concave mold positioned above the glass sheet and engaging the upper surface thereof; Fig 4 is a side elevation of the concave mold of Fig 3 in inverted position and with the bent glass sheet supported thereon; Fig 5 is an end view of the two molds shown in Fig 3, Fig 6 is a diagrammatic plan view of a bending furnace used in the production of tempered glass sheets; Fig 7 is a diagrammatic plan view of a bending and annealing furnace; Fig 8 is a diagrammatic plan view of a bending furnace used in conjunction with a reheating and tempering furnace; and Fig 9 is a partial longitudinal section along the center line of the bending furnaces shown in Figs 6 and 7. According to the present invention there is provided a method of bending glass sheets, comprising heating a glass sheet to be bent to bending temperature and preliminary bending the same to a predetermined curvature, inverting the bent sheet and supporting it on a shaping surface having a curvature to which the sheet is to be finally bent, bending the sheet to its final curvature upon said shaping surface, and then cooling the bent sheet. The invention also contemplates the provision of apparatus for bending glass sheets, comprising a bending furnace having a heating chamber with charge and discharge open 70 ings therein, means for moving a pair of superimposed convex and concave shaping surfaces along a predetermined path within said heating chamber, and shaping surface engaging means within said heating chamber 75 between the charge and discharge openings for inverting said shaping surfaces. With reference now to the drawings, and particularly to Fig 1, a portion of the bending apparatus herein provided for carrying 80 out the method of the invention is generally designated by the numeral 10, and comprises a rack 11 upon which is supported a male or convex bending mold 12. The rack 11 comprises an open substan 85 tially rectangular framework having opposite end sections 13 rigidly connected to one another by longitudinally disposed side rails 14 As seen in Figs 1 and 5, the end sections 13 comprise spaced end bars 15 and 16 90 joined together by vertical members 17 which, at their lower ends, are joined to the side rails 14 Arranged transversely between the side rails 14 are a plurality of spaced support rods 18, and a lift bar 1995 with which, as later described, the mold may be handled. The mold 12 includes a continuous rail having a shaping surface 21 formed on the upper surface thereof and which comprises 100 a pair of

spaced parallel side rails 22 having a relatively shallow curvature in their central portions a and downwardly directed comparatively sharply curved end portions b. To complete the rail 20, the side rails 22 are 105 connected to one another at their opposite ends by transversely disposed end rails 23. To support the rail 20 and to impart rigidity thereto, a plurality of spaced cross rods 24 may be secured to the undersides of the side 110 rails 22 and said rods, in turn, supported at the upper ends of vertical members 25 having their lower ends seated on the support rods 18 inwardly of the rack side rails 14. In Fig 3 is illustrated another bending 115 apparatus 26 which is employed with the mold shown in Figs 1 and 2 in carrying out the method of this invention The apparatus 26 comprises a rack 27 and a female or concave bending mold 28 The rack 27 is 120 rectangular in shape and comprises end sections 29 joined to one another by longitudinal side rails 30 As seen in Fig 5. each of the end sections 29 comprises spaced transverse bars 31 and 32 terminating 125 in vertical members 33 which, at their upper ends, are joined to the side rails 30 The opposite end of each of the members 33 extends downwardly beyond the side bars 32 and is capped with an angle 34 which extends 130 784,972 beyond the end of said member. The mold 28 is similar in plan view (Fig. 21 to the mold 12 and has a continuous rail having a shaping surface 36 formed on the lower edge thereof which conforms to the curvature of the shaping surface 21 of the rail As seen in Figs 2 and 3, and as will be later described, the matching shaping surfaces 21 and 36 are substantially rectangular in plan view and coact to grip a block size glass sheet 37 therebetween to properly effect the bending of the same. The continuous rail 35 has a supporting structure similar to that of the mold 12 connecting it to the rack 27 This supporting structure comprises a plurality of rods and bars 38, 39 and 40, which correspond to the respective members 24, 25 and 18 of the mold 12 As a means of handling the mold, a lift bar 41 is provided between the side rails of the rack 27. Figs 6 to 8 show, in diagrammatic form, various types of furnaces which have been adapted to perform the invention The furnace 42 shown in Fig 6 is adapted to both bend and temper glass sheets and comprises a heating section 43 having a charge end A and a discharge end B A conveyor 44 is provided for conveying molds through the furnace and an air hood 45 is provided over the conveyor 44 outwardly of the discharge end of the heating chamber for tempering the bent sheets as they leave the furnace As will be later described, means is provided for inverting the molds while they are within the frame and when they

are in the position shown in Fig 3 This means is housed within cubicles 46 extending outwardly from the furnace adjacent the discharge end thereof. As shown in Fig 7, the furnace 47 is of the general type known as a continuous bending and annealing furnace and comprises a bending section 48 and a connected annealing section 49, -the division, point therebetween being indicated by the phantom line x-x. Outwardly extending cubicles 46 are provided in the bending section for housing the mold inverting means, and a conveyor 50 extends through the furnace for bearing molds into the charge end C and out the discharge end D. The partial longitudinal cross section shown in Fig 9 applies to each of the furnaces 42 and 47 shown in Figs 6 and 7 As there shown, a trap door arrangement 51 is provided in the furnace roof 52 immediately ahead of the cubicles 46 over the furnace conveyor, and a similar trap door arrangement 53 is provided in the roof immediately after the cubicles As will be later described, these doors permit the concave mold 28 to be lowered into the furnace on top of the mold 12, and after the molds are inverted, the mold 12 may then be removed from the furnace. The furnace system shown in Fig 8 may be used in producing pattern cut tempered glass sheets This system includes a bending furnace 54 having a charge end E and a discharge end F A conveyor 55 is provided for 70 conveying molds through the furnace A sheet handling and cutting station 56 is provided at the discharge end F of the furnace 54 and immediately adjacent thereto is a reheat furnace 57 which has a conveyor 58 75 for bearing molds into the charge end G thereof and out the discharge end H and then beneath a tempering hood 59. In describing how the method of the invention may be best performed, the male 80 mold 12 will be referred to as the convex shaping surface, and the female mold 28 will be referred to as the concave shaping surface. According to the invention, the glass sheet 85 37 to be bent is positioned upon the convex shaping surface and, as shown in Fig 1, is supported by said shaping surface substantially at its midpoint In a bending and annealing operation, the convex shaping 90 surface having the sheet 37 thereon is placed on the conveyor 50 and passed through the charge end C of the bending and annealing furnace 47 Upon passage through the furnace the glass sheet is subjected to sufficient 95 heat in the bending zone 48 so as to cause the sheet portions outwardly of the midpoint to sag downwardly and bend into conformity with said shaping surface In its passage through the furnace 47 and, as shown in Fig 9, 100 the sheet 37 is bent prior to arriving beneath the trap door arrangement 51 in the furnace roof 52 When the convex shaping

surface bearing the now bent sheet is beneath the trap doors, the doors are opened and the con 105 cave shaping surface, which may be supported by a hook 60 and preferably heated to the temperature of the bent sheet, is lowered therethrough When so lowered, and as seen in Figs 3 and 5, the angles 34 of the 110 rack 27 engage the, uprights 17 of the rack 11, and guide the concave shaping surface into contact with the bent glass sheet 37. With the concave shaping surface in place and engaging the upper surface of the bent 115 sheet, the pressure created upon the marginal portions of the sheet which is maintained at bending temperature, due to the weight of said shaping surface, causes those portions to accurately conform to the curvature of 120 the convex shaping surface The two shaping surfaces, having the sheet 37 therebetween, are then advanced forwardly in the furnace a limited distance until they arrive opposite the cubicles 46 which house the means for 125 inverting the molds. It was previously mentioned in connection with the bending of automotive windshields and back windows on a convex mold, that the sag in the bent sheet will give a "caved 130 784,972 in" effect to the sheet when installed in an automobile To avoid this objectionable feature, and in carrying out the invention, the two shaping surfaces having the glass sheet 37 therebetween are inverted while the sheet is substantially at bending temperature so that the sheet is then supported upon the concave shaping surface and receives its finished contour when supported by said It, shaping surface When supported upon the concave shaping surface, the sag in the sheet is reversed, that is, gravity acting upon the sheet, which is still preferably maintained at substantially bending temperature, causes the central portion of the sheet to deflect downwardly a limited distance Then, when the sheet is subsequently cooled and installed in an automobile, the under surface c is disposed toward the outside and will have a slightly arched appearance which is pleasing to the eye. As shown in Fig 3, in phantom lines, the means for inverting the shaping surfaces may comprise a pair of rotatable jaws 61 each of 2 which having inwardly directed beveled end portions 62 When the shaping surfaces arrive opposite the cubicles 46, the jaws are moved inwardly toward the supporting racks and the beveled end portions 62 engage the side bars 15 and 32 o'f the respective rack end sections 13 and 29 and act in such a manner as to tightly clamp said end sections to one another When so clamped, the jaws, which may be supplied with a suitable source of rotative power, are rotated 180 degrees thereby inverting the shaping surfaces so that the convex surface is now on top and the concave shaping surface is beneath and supports the bent glass sheet 37 During rotation, due to the clamping action of the jaws

on the racks, the shaping surfaces exert a continuing pressure on the marginal area of the glass sheet clamped therebetween so that there is no danger of the sheet slipping. 4 S After the shaping surfaces have been thus inverted, the convex shaping surface is no longer needed and may be immediately disengaged from the glass sheet or, as shown in Fig 9, the two surfaces having the sheet therebetween may be advanced a further limited distance in the furnace until they are beneath the second trap door arrangement 52 The doors thereof are then opened and the hook 60 may be lowered to lift the convex shaping surface from engagement with the bent sheet and remove said shaping surface from the furnace The concave shaping surface now bearing the sheet is then advanced through the remainder of the fur6 CJ nace bending zone and then through the annealing zone wherein the sheet is slowly cooled In passing through the balance of the bending zone, the sheet accurately conforms itself to the concave shaping surface if it has not already done so, and the reverse sag in the central portions, if not effected during the inverting step or shortly thereafter, then is accomplished. It will be understood, of course, that the terms bending and annealing zones are rela 70 tive and do not in most cases actually embody a physical change in the furnace but rather a change of temperature As shown in Fig 9, the inverting of the shaping surfaces takes place within the bending zone 48 75 of the furnace 47 In the method of the invention, the inverting of the shaping surfaces may take place at any time before the sheet has reached the temperature at which it will retain its final bent shape if left unsupported 80 provided, however, that the sheet is sufficiently hot to enable the reverse sag of the central portion to take place when the sheet is supported by the concave shaping surface. In tempering Alass sheets bent in accord 85 ance with the invention, the furnace 42 shown in Fig 6 may be used In this furnace, the glass sheet is placed on a convex shaping surface which is then conveyed through the furnace and through the bending zone there 90 of After the sheet is bent, the upper surface thereof is then engaged with the concave shaping surface, the two shaping surfaces inverted, and the convex shaping surface then withdrawn from contact with the bent sheet 95 since it no longer serves an essential purpose. While the sheet is still maintained at substantially bending temperature and supported by the concave shaping surface so that the central portion thereof sags down 100 wardly, it emerges from the discharge end B of the furnace and passes beneath the air hood 45 While thereunder, the sheet is subjected to a blast of air which effects the case hardening or tempering of the now bent 105 sheet. The furnace system shown in Fig 8 is used for performing the method of

the invention when it is desired to perform the inverting step outwardly of a bending furnace A 110 block size glass sheet 63 to be bent is supported upon a convex shaping surface 64 and placed on the conveyor 55 whereby it is passed through the furnace 54 and bent into conformity with said shaping surface Upon 115 emerging from the discharge end F of the furnace, the sheet 63 which need only be cool enough to be handled, is removed from the shaping surface 64 and a patterned sheet cut therefrom The pattern cut sheet is 120 then inverted into concave position and placed on a concave shaping surface 66 having a contour which matches the sheet The shaping surface 66 is passed into the reheat furnace 57 and the sheet 65 reheated to bend 125 ing temperature At such temperature the reverse sag of the central portion of the sheet takes place While being maintained at sufficient temperature for tempering, the sheet emerges from the discharge end H of 130 784,972 the furnace and passes beneath the air hood 59 which directs a blast of air at the sheet to effect the tempering of the same However, it will be understood, that the tempering hood 59 could be omitted and that the sheet could then be passed through an annealing furnace to produce an annealed bent sheet.

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