US3488936A

US3488936A - Warp twisting apparatus

Info

Publication number: US3488936A
Application number: US683908A
Authority: US
Inventors: William K Wyatt
Original assignee: Turbo Machine Co
Current assignee: Warner and Swasey Co; Turbo Machine Co
Priority date: 1967-11-17
Filing date: 1967-11-17
Publication date: 1970-01-13
Anticipated expiration: 1987-01-13
Also published as: ES360690A1; BE723891A; DE1808994A1; GB1215038A; FR1604273A; NL6816382A; CH498215A

Description

Jan. 13, 1970 w. K. WYATT 3,488,936

WARP TWISTING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet l INVENTOR. Wi LLIAM KRK VVYATT ATTORN EYS.

Jan. 13, 197() wl K wYATT 3,488,936

WAR? TWI STING APPARATUS Filed NOV. 17, 1967 5 Sheets-Sheet 2 o o I O o o o o #ed o O o o 09160 /Q 4 FQ.' 5. u 11\IVENTOR.

WILLIAM KIRK WYATT M PFW@ ATTORNEYS.

mgm

Jan. 13, 1970 w. K. WYATT 3,488,936

wma? TwIsTING APP RATus Filed Nov. 17, 1967 5 vA j ets-Sheet 3 LD N l MPM WILL-mm KIRK WYATT BY Jan. 13, 1970 W, K, WYATT 3,488,936

WARP TWISTING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet 4 www@ /Lcl KYB ` INVENTOR.

WILLIAM KIRK WYATT ATTORNEYS.

WARP TWI STING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet f' INVENTOR.

WILLIAM KIRK VI/YATT .Y MPM ATTORNEYS.

United States Patent O U.S. Cl. 57-77.4 7 Claims ABSTRACT OF THE DISCLOSURE An apparatus is provided, for machine twisting a plurality of warp yarns simultaneously, for providing an initial twisting of yarns. After the initial twist is placed in the yarns, by false twisting pairs of yarns together, the yarns are moved longitudinally through another portion of the apparatus, in which yarns in the twist zone are heated to set the filaments in their twisted condition, the twisted yarns then being cooled by a suitable means, and then being separated by passing the yarns in a twisted pair over opposite sides of a separating pin, to yield a texturized fabric.

BACKGROUND OF THE INVENTION Prior art devices have utilized the principle of twisting together pairs of warp yarns, as in a false twistingoperation, and then separating the yarns to yield texturized, or bulked yarns. Such prior art devices, for example that disclosed in the U.S. Patent No. 3,091,908 to Carruthers, have proven excellent in their ability to provide quality yarns, particularly those of finer denier.

In general, it has heretofore been thought necessary to always accomplish the pre-twisting and separation operation as well as all other yarn handling operations, at as high a speed as possible, for effecting economy of the time required for yarn handling operations.

Such operations generally required drawing yarns from pirns, twisting the yarns together, either manually or by using a pretwister device such as that disclosed in the U.S. Patent No. 3,237,391 to Carruthers, heat-setting and separating the twisted yarns, winding the yarns on bobbins or the like, placing the bobbins in a creel, and unwinding the bobbins with the texturized yarns being wound in parallel relation onto a beam, such as oneA of the tricot type. The yarns were then fed to knitting inachines at the comparatively slow speeds required by knitting machines.

The prior art has lacked any teaching of using mechanical means for placing false twist in pluralities of pairs of yarns simultaneously, by other than a hand operation, and furthermore clearly lacks any teaching of false twisting pluralities of groups, or pairs of yarns for direct feed of the yarns to a knitting machine or the like.

SUMMARY OF THE INVENTION The present invention seeks to fulfill a need not fulfilled by the prior art, in providing an apparatus by which parallel-disposed yarns rnay be twisted together simultaneously, in pairs, such that all or a substantial nurnber of pairs of yarns across a knitting machine or the like may be twisted in a single operation, thereby eliminating the necessity for twisting yarns by hand, and furthermore insuring that substantially the same degree of twist is present in each pair of yarns, across the machine.

Additionally, the present invention provides an apparatus embodying the above-mentioned features, which may be operated at suiciently low yarn fed speeds that it can be mounted directly onto a knitting, weaving machine or the like, and which is capable of handling either fine or heavy denier yarns.

3,488,936 Patented Jan. 13, 1970 ICC Accordingly, it is a primary object of this invention to provide an apparatus for twisting yarns simultaneously into a plurality of generally parallel-disposed twisted groups, each group comprising two or more yarns, as desired.

It is another object of this invention to accomplish the above object, wherein means are provided, carried by the apparatus, for engaging a plurality of groups of yarns, each group comprising a pair of yarns, and applying false twist to the groups of yarns.

It is a further object of this invention to provide an apparatus for applying false twists to a plurality of grouped pairs of yarns by engaging the yarns between oppositely moving belt runs.

It is a further object of this invention to accomplish the above object, wherein the yarns are separated into groups simultaneously by transversely movable members which carry grouping pins or the like.

It is yet another object of this invention to provide a means for simultaneously applying false twists to pluralities of generally parallel-disposed pairs of yarns, wherein spacing means are provided for maintaining the yarns in each pair in spaced relation for a portion of the twist zone, to facilitate insertion of a separating member between the spaced yarns in each pair, whereby the twist may be removed from each pair of yarns, by moving the yarns past separating members resulting in a plurality of texturized yarns.

It is a further object of this invention to accomplish all of the above objects, wherein the apparatus for applying the false twist to pairs or groups of yarns is mounted directly on a knitting machine, or the like.

It is a further object of this invention to provide an apparatus for applying false twists to pairs of yarns and heat-setting the yarns in twisted condition, with the apparatus also including pin means rfor separating the yarns from their twisted condition, the pin means being Vibratory due to the transfer thereto of energy from yarns moving therepast, wherein the vibratory motion of the pin means facilitates the removal of snags and the like from the yarns moving therepast.

Other objects and advantages of this invention will be apparent to those skilled in the art from the following detailed description, drawings, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a top perspective View of a knitting Inachine which embodies the yarn twisting apparatus of this invention, means for heat-setting the twisted yarn filaments, and separating pins for separating yarn pairs conveyed longitudinally therepast.

FIGURE 2 is a top plan view of the yarn twisting belts of this invention, wherein grouping means are also illustrated for grouping the yarns into pairs, prior to applying a false twist to each pair of yarns.

FIGURE 3 is a front view of the yarn twisting means illustrated in FIGURE 2, taken generally along the line III-III of FIGURE 2, wherein means are illustrated for facilitating relative vertical movement of the upper and lower belt runs which engage and apply false twists to grouped pairs of yarns disposed therebetween.

FIGURE 4 is an enlarged fragmentary top plan view of that portion of the apparatus of this invention which facilitates the grouping of yarns into pairs.

FIGURE 5 is a view generally similar to that of FIG- URE 4, but wherein the grouping means are illustrated in their respective positions, after relative movement, such that the yarns are illustrated as having been disposed in grouped pairs, after slight transverse movement of the yarns by means of pins carried by the grouping members.

FIGURE 6 is an enlarged fragmentary top perspective view of a portion of the machine of FIGURE 1, wherein there is illustrated a lower twisting belt, yarn-grouping pin means disposed on opposite sides of the belt, a yarnsetting heater means, a taping block, and twist separating pins disposed in a retracted position between the lower twisting belt and the taping block means.

FIGURE 7 is a view generally similar to that of FIG- URE 6, after yarns have been grouped into pairs, and wherein the means facilitating the taping operation and tape cutting is clearly illustrated.

FIGURE 8 is a fragmentary top perspective view of a portion of the machine illustrated in FIGURE 1, wherein the operation of the device of this invention is illustrated in a sequence subsequent to that illustrated in FIGURE 7, and wherein the twisting belts are illustrated in operative relation, for applying a false twist to pairs of yarns disposed therebetween, the taping block not being illustrated, in that it is in a retracted position during the operational stage illustrated in FIGURE 8.

FIGURE 9 is a view generally similar to that of FIG- URE 8, but wherein the twisting belts and grouping pins are not illustrated, for the sake of clarity, such apparatus having been retracted following the operational stage illustrated in FIGURE 8, and wherein the twist separating pins are illustrated in upper, or operative positions.

FIGURE 10 is a highly enlarged view taken generally along the line X-X of FIGURE 8, looking downstream of the apparatus of this invention, during the twisting operation illustrated in FIGURE 8.

FIGURE 11 is an enlarged view of a twist separating pin of this invention, mounted for angular disposition relative to a vertical plane, the View being taken from one side of the pin, illustrating the manner in which the pin facilitates the separation of a twisted yarn pair.

FIGURE l2 is a view generally similar to that of FIG- URE 11 but wherein the separating pin is mounted in vertical disposition, the pin being disposed for vibration in the direction of yarn travel, as illustrated by the phantom position of the pin in FIGURE 12.

FIGURE 13 is an enlarged fragmentary top perspective view of a portion of an apparatus generally similar to that of FIGURE 1, but wherein the twist separating pins are mounted in downward disposition, adjacent to the twistsetting heating means of this invention, in which position of the separating pins the pairs of spaced yarns must be moved rearwardly for engaging the pins, following their twisting operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail, reference is first made to FIGURE 1, wherein there is illustrated a knitting machine generally designated by the numeral 15.

The machine 15 comprises a frame 16 having a front wall 17 and

side walls

18 and 20. The

frame side walls

18 and 20 include respective side

wall mounting extensions

21 and 22.

A sley bar 23 is carried by the

mounting extensions

21 and 22 of the

frame side walls

18 and 20, at the left-most ends thereof, as viewed in FIGURE 1. The sley bar 23 includes a plurality of upstanding separator pins 24, for spacing and separating yarns passing therebetween.

A pair of

upstream nip rolls

25 and 26 are rotatably carried 'by the

frame extensions

21 and 22, peripherally adjacent to each other to provide a nip therebetween for receiving and carrying yarns therebetween, longitudinally of the machine 15. The roll 26 includes a shaft extension 27, which extends through the frame extension 21 and has a sprocket 28 keyed or otherwise secured to the shaft 27; the shaft 27 being driven by a suitable motor 30.

A heater 31 is provided, disposed transversely of the machine 15 and carried between the

frame extensions

21 and 22, the heater 31 being disposed ust below the paths of yarns extending through the nip of the

rolls

25 and 26, as viewed in FIGURE 6, and later to be described.

A belt mounting bar 32 is disposed transversely of the machine, between the

frame extensions

21 and 22, fixedly secured at opposite ends to the

frame extensions

21 and 22. A pair of

shafts

33 and 34 are carried by the bar 32, to one side thereof, as viewed in FIGURE 2, the shaft 33 carrying an idler pulley 35, and the shaft 34 carrying a drive pulley 36. The pulley 36 is driven through the shaft 34, by means of a motor 37. The motor 37 is carried by a bracket 38 which is mounted to the bar 32 by suitable bolts 40 which fasten together the bracket 38, the bar 30, and a bracket 41 disposed on the opposite side of the bar 32. A belt 42 is disposed between the

pulleys

35 and 36, being driven by the pulley 36.

An upper bar 43 is disposed between the

frame extensions

21 and 22, directly above the bar `32, the bar 43 being mounted for pivotal movement on a bolt 44 disposed between and carried in slots of the

brackets

38 and 41. The right-most end of the bar 43 is provided with a universal joint 45, in which is carried one end of a threaded member 46. The threaded member 46 is threaded into a pivotal member 47 which is pivotally carried by the right-most end of the bar 32, as viewed in FIGURE 3. The lower end of the threaded member 46 may be provided with a suitable crank turning device or the like, to facilitate the rotation of the threaded member 46 and the consequent raising or lowering of the bar 43, relative to the bar 32.

The bar 43 is provided with

shafts

48 and 50, extending therethrough, and carrying respective idler and drive

pulleys

51 and 52.

The shaft 50 is provided with a sprocket 53 which is driven through a reversing sprocket 54 by a drive sprocket 55 carried by the shaft 34. The

pulleys

51 and 52 carry a belt 56 therebetween. It will be apparent from the assembly of the device as illustrated in FIGURE 3, that the

belts

42 and 56 are driven in a same direction such that the lower run of upper belt 56 is oppositely movable relative to the upper run of the lower belt 42. Also, it will be noted that the permissible raising and lowering of the upper bar 43 upon rotation of the threaded member 46 will permit the movement of the

bars

32 and 43 relative to one another, such that the lower run of the upper belt 56 is movable into closely adjacent, or touching (if desired) relation to the upper run of the lower belt 42.

Yarn grouping means, generally designated by the numeral 57 are provided, comprising

plate members

58 and 60 disposed on an upstream side of the lower belt 42, as viewed in FIGURE 6, and a pair of plate members 61 and 62 disposed on a downstream side of the lower belt 42. The

plate members

58, 60, 61 and 62 carry upstanding grouping pins 63, spaced transversely across the machine 15, equidistant from one another along each plate member, the pins 63 being disposed in aligned relationship, as viewed in FIGURE 6, in one position of the grouping means 57. An actuation member 64 is provided, secured to the plate member 58, which, when manually or otherwise actuated, is operative to move the plate members 58 and 61 transversely of the machine 15, as viewed in FIGURE 7, in such a manner that upstanding pins 63 carried by the plate members 58 and 61 will engage yarns for movement of the yarns slightly transversely of the machine 15, to form pairs, in a manner later to be described.

A bar 65, is provided, extending transversely of the machine 15, between the

frame extension portions

21 and 22 thereof. The bar 65 is carried in slots 68 and 70, for selective vertical movement between operational and retracted positions, upon actuation of a crank handle 72 on one or both sides of the machine 15, which drives threaded members 74, which are threaded through the

frame extension portions

21 and 22, at both sides of the machine 15, and into engagement with the bar 65. A plurality of twist-separating pins 75 are carried by the bar 65 for vertical movement therewith.

A tape block 76 is provided, mounted between the

frame extension portions

21 and 22, transversely of the machine 15, for vertical movement within a pair of

slots

77 and 78 in the

frame extension portions

21 and 22, generally similar to the movement o'f ythe needle bar 65. A suitable crank 80 and threaded member 81 are provided, suitably connected at one or both ends of the bar 76, through the

frame extension portions

21 and 22. The tape block 76 is thus movable between operational and retracted positions in a vertical direction. A plurality of cutting elements 82 are disposed above the cutting block 76, for vertical movement theretoward. The cutting elements 82 are of the blade type, and facilitate the cutting of tape, for a purpose later to be decribed.

A pair of

downstream rolls

83 and 84 are provided, rotatably carried between the frame sides 18 and 20, defining therebetween a nip for engagement of and driving yarn ends therethrough. The lower roll 84 includes a shaft extension 85, on which is mounted a sprocket 86. The sprockets `86 and 28 carry a drive chain 87, whereby the lower rolls 84 and 26 of the upstream and downstream roll pairs are rotatably driven in the same direction by the motor 30.

The remaining structure of the knitting machine 15 from the roll 89 on through the machine may be conventional, or suited to specific purposes, as desired.

A beam or spool 88 may be mounted on a shaft 9'0, upstream of the machine 15, for supplying yan1 to the machine 15. In the alternative, yarn may be supplied to the machine from a plurality of spindles (not shown) disposed in a creel, if desired.

OPERATION A plurality of yarns Y are provided from a beam 88, and are threaded through the nip between the

rolls

25 and 26, over the heater 31, as viewed in FIGURE 6, over the

plate members

58 and 60, between the upper and

lower belts

56 and 42, respectively, over the plate members 61 and 62, above the separator pin bar 65, over the tape block 76, and through the nip formed between the

rolls

83 and 84, the movement of the yarn ends Y then being arrested.

The actuation portion 64 of the plate member 58 is then moved transversely of the machine, in a horizontal direction, whereby the plate members 58 and 61 are moved transversely of the machine, the grouping pins 63 carried by the plate members 58 and 61 engaging the yarns Y1 and Y2 and moving them toward the yarns Y1, and Y4, as viewed in FIGURE 7. It will be understood that alternate yarns disposed between in nips of

Arolls

25, 26 and 83, 84 across the machine 15 will be moved in a manner of the yarns Y1 and Y2.

The yarns Y1 and Y3, as well as the yarns Y2 and Y.1 are thus grouped in pairs transversely of the machine 15.

Prior to the grouping of the yarns Y1, Y2, Y3 and Y1 a piece of 'tape T1 or other adhesive element is placed adhesive side-up on the tape block 76. Subsequent to the grouping of the yarns in the aforementioned manner, another piece of tape T2 is applied across the yarns Y1, Y2, Y3, Y.1 into overlying relation to the piece of tape T1. The cutting blades 82 are then moved vertically downwardly, to cut through the tapes T1 and T2, and to separate the tapes into spacer members S1 and S2. The upstanding pins 79, carried by the tape block 76 maintain the adjacent yarn portions Y1, Y2, Ys and Y1 in` their originally spaced relation, transversely of the machine prior to the application of the tape member T2.

The cutting blades 82 are then withdrawn upwardly and the tape block 76 is moved into a retracted position by engaging the crank handle 80 and rotating the threaded member 81 to lower the tape block '76 within the

slots

77 and 78. The upper belt 56 is then lowered to the position illustrated in FIGURE 8, by actuation of lthe threaded member 46.

The

belts

56 and 42 are thus brought together, such that adjacent runs are in overlying relation with the yarns Y1 through Y, confined therebetween. Upon energizing the motor 37, and rotation of the

belts

56 and 42, the lower run of the upper belt 56 moves in a direction opposite to the movement of the upper run of the lower belt 42, thereby providing a twist in each of the groups G1 and G2 of yarns. The twist applied to the groups G1 and G2 is of the false twist type, known in the art as a S-Z twist. During the application of this twist to the yarn groups G1 and G2, the respective spacer members S1 and S2 are freely rotatable, having been separated -by the cutting blades 82. The twist zone will be present from the nip of the

rolls

25 and 26 to the nip of the

rolls

83 and 84.

With reference to FIGURE 10, it will be readily apparent that the false twist applied to the yarns Y2 and Y1 is effected by frictional engagement of the yarn surfaces with the surfaces of the oppositely moving belt runs 42 and 56.

When 'the desired number of twist turns has been placed in the yarns, the motor 37 is de-actuated, the plate members 58 and 61 are returned to their normal positions illustrated in FIGURE 6, and the threaded member 46 is rotated, raising the bar 43 and consequently rai-sing the upei belt 56 out of engagement with the yarn groups G1 au 2.

The crank handle 72 is then actuated, raising the separator bar 65 in its guide slots 68 and 70 such that the separator pins 75 are raised to pass through the voids V1 and V2 between the respective yarns Y1, Y2 and Y2, Y4, which are spaced by the respective separator members S1 and S2.

The heater 31 is then operative to heat-set the yarn filaments in their twisted condition. The motor 30 is then actuated to drive the

rolls

26 and 84, to carry the twisted yarn groups G1 and G2 in a downstream direction, such that the yarns Y1 and Y3 are separated from their group G1 as they pass over one of the separator pins 75, and the yarns Y2 and Y1 are separated from their group G2 as they pass on opposite sides of their separator pln 75. All yarn groups across the machine 15 are separated in the same manner, and the tape separator members S1 and S2 may then be removed, or allowed to pass between the

rolls

83 and 84, then to be discarded.

During the continuous heat-setting of the twisted yarn groups G1 and G2, the zone of twist remains constant,

and as a given amount of twist is removed at the downstream end of the twist zone by yarns passing on opF poslte sides of the yarn separator pins 75, that same amount of twist yautomatically becomes present at the upstream side of the twist zone, for each group G1 or G2 of yarns, as yarns pass through the nip between the upstream rolls 25 and 26. This is due to the heat-setting of the twist as yarns are drawn across the heater 31, and the transfer upstream of any rotation to a twisted group G1 or G2 by a downstream untwisting of the group G1 or G2; such untwisting being eiected by passing them over separator pins 75.

With reference to FIGURE l2, it will be observed that the separator pin 75 is of a selected size, dimension, and material, such that the friction of the yarns Y1 and Ya passing thereby, on opposite sides of the pin 75 is sufficient to transfer energy to 'the pin 75, to facilitate a vibration of the pin 75, between the full line position illustrated in FIGURE 12, and the phantom line position illustrated therein. All such pins 75`across l'the machine 15 are thus vibrated. This vibration of the pins 75 is elective for eliminating snags between the yarns Y1 and Ys which would tend to retard the separation of the yarns about the pins 75, or which may 'tend to cause breakage of the yarns Y1 and Ya. The resilience of each pin 75, is therefore suicient to allow a moderate bending of each pin 75 to ease the elimination of snags and the like.

With reference to FIGURE l1, it will also be observed that the pins 75 may be mounted in a angular manner, at a slight acute angle with a vertical plane, such that the yarns Yl and Y3 may ride upwardly of the pins 75, when a snag engages a pin 75, another feature which eases the elimination of snags and prevents yarn breakage.

It will be observed that in the device illustrated, adjacent pairs of yarns have been twisted in the same direction. However, it may be advisable to twist alternate pairs of yarns in opposite directions, in order to balance forces in the yarns across the knitting machine. .Such may be accomplished by first rotating the

belts

56 and 42 in one direction across alternate pairs of yarns and then rotating the

belts

56 and 42 in another direction across intermediate pairs of yarns. Other apparatus may also be provided, such as another pair of

belts

42 and 56 which move in directions opposite to those illustrated in FIGURE 8, and are disposed either above or below those illustrated in FIGURE 8, for applying twist in an opposite direction to alternate pairs of yarns.

The yarns which pass through the

rolls

83 and 84 in a downstream direction are texturized, and have high bulk, which enables the accomplishment of the aforementioned objectives.

With reference to FIGURE 13, it will be observed that an alternative embodiment of the apparatus of this invention is present, comprising a knitting machine 90 having

frame extensions

91 and 92, between which are carried

upstream rolls

93 and 94 and

downstream rolls

95 and 96. A heater 97 is also provided between the

frame extensions

91 and 92, as are upper and lower belts 98 and 100, yarn grouping means 101, and a tape block 102 and its pin-carrying

guide bars

103 and 104, al1 similar to the apparatus of FIGURE 1 of this invention.

In the apparatus of FIGURE 13, however, yarn twist separator pins 105 are carried extending vertically downwardly from a carrier bar 106 disposed just downstream of the heater 97, but upstream of the twist belts 98 and 100 for those instances when it is desirable to separate twisted yarn groups shortly after the yarn filaments are set by the heat from the heater 97.

In the embodiment of FIGURE 13, it therefore becomes necessary after applying the false twist to the yarns, and prior to separating the yarns over the pins 105, to manually grasp the separator members S1 and S2 and move the yarns back upstream to engage the voids V1 and V2 of the groups of yarns G1 and G2, respectively, over separator pins 105. From that point on, the operation would be continuous, as with the apparatus of FIGURE 1, differing therefrom in a shorter twist zone only.

It will be apparent that various modifications may be made in the various structural details of this invention such as using a cooling zone of the forced air type, or the like just downstream of the heater, should the cooling of heat-set yarns be desirable in specific applications of this invention, without departing from the spirit and scope of the invention as defined in the appended claims.

In the description above, specific terms have been used for the sake of clarity, but it is to be understood that this description is directed to the specific forms of the invention selected for illustration in the drawings.

What I claim is:

1. An apparatus for twisting yarns comprising means for retaining a plurality of closely spaced yarns in generally parallel disposition, means for separating said yarns into groups, and transversely movable means for simultaneously engaging a plurality of said groups of yarns and applying false twists to said groups of yarns.

2. The apparatus as defined in claim 1 wherein said transversely movable means is selectively positionable into and out of engagement with a plurality of said groups of arns. y 3. The apparatus as defined in claim 1 wherein said transversely movable means comprises oppositely movable generally planar members.

4. The apparatus as defined in claim 3 wherein said members comprise belt runs.

5. The apparatus as dened in claim 1 wherein said separating means comprise guide members disposed upstream and downstream of said transversely movable means and being movable into adjacent relation in groups, with a pair of guide members being provided for each yarn to be grouped with one member of each said pair being disposed on each side of said transversely movable means.

6. The apparatus as defined in claim 1 wherein said separating means isoperative to separate yarns into groups of two yarns per group.

7. The apparatus as defined in claim 3 wherein said members comprise separate upper and lower oppositely driven belt runs, at least one said run being movable toward the other said run, to dispose said upper run into generally overlying relation to said lower run.

y References Cited UNITED STATES PATENTS 2,262,589 411/1941 Peck 57-77.4 XR 2,908,133 10/1959 Brown 57-77.4 3,045,416 7/1962 Ubbelohde 57-34 XR 3,148,520 9/ 1964 Biggers 66-l25 3,154,906 11/1964 Assendelft et al 57-34 3,434,275 3/1969 Backer et al 57--156 XR FOREIGN PATENTS 611,455 10/1960 Italy.

DONALD E. WATKINS, Primary Examiner U.S. Cl. X.R. 57-51.6; 66-125