US3057577A

US3057577A - Method and device for unwinding conical-layer yarn coils such as cops

Info

Publication number: US3057577A
Application number: US757757A
Authority: US
Inventors: Ruhl Manfred
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-08-31
Filing date: 1958-08-28
Publication date: 1962-10-09
Anticipated expiration: 1979-10-09

Description

Oct. 9, 1962 M. RUHL 3,057,577

METHOD AND DEVICE FOR UNWINDING CONICAL-LAYER YARN coILs SUCH AS coPs 2 Sheets-Sheet 1 Filed Aug. 28, 1958 Oct. 9, 1962 M. RUHL 3,057,577

METHOD AND DEVICE FOR UNWINDING CONICAL-LAYEIR YARN COILS SUCH AS COPS Filed Aug. 28, 1958 2 Sheets-Sheet 2 i 52JL United States Patent ()fiice 3,057,577 Patented Oct. 9, 1962 3,057,577 METHGD AND DEVICE FOR UNWINDING CONE- CAlL-LAYER YARN COILS SUCH AS COPS Manfred Riihl, Rheydt, Germany, assignor to Walter Reiners, M. Gladbach, Germany Filed Aug. 23, 1953, Ser. No. 757,757 Claims priority, application Germany Aug. 31, 1957 15 Claims. (Cl. 242-128) My invention relates to a method and means for removing by unwinding the yarn content of coils, for example spinning cops, Whose body or package of yarn is formed by conical layers of turns such as those schematically indicated at item 6:! in FIG. of the accompanying drawings more fully described hereinbelow.

Conical-layer coils are preferably used in cases where the yarn content is to be removed from the coil, for eye ample in a yarn re-winding machine, by pulling the yarn off in a direction generally parallel to the coil axis. Such unwinding in over-the-tip fashion has the advantage that the coil, during unwinding, need not be placed in rotation, so that when the operation is suddenly stopped, no appreciable mass need be decelerated and that, when the unwinding operation is suddenly commenced, no or only negligible masses of yarn, namely only the mass of the outgoing yarn portion, must be placed in rotation. However, appreciable limits are still imposed upon the proper unwinding speed, particularly if very thin or very sensitive yarns are being processed, due to such residual mass forces as those of acceleration and centrifugation, the Coriolis force, the force of the unwinding pull exerted upon the yarn, or the air resistance.

During the unwinding of the yarn from the coil, two forces among those mentioned are mainly effective to appreciably influence the proper take-off speed. These are the force required for accelerating the mass of the yarn, and the force exerting itself as centrifugal force due to the fact that the yarn being pulled off the stationary body of the coil rotates about the coil body. These two forces superimpose themselves upon each other and for that reason they may exert a considerable and undesired pull upon the yarn running off the coil. Due to this pulling force the amount of yarn still Wound up on the coil is subjected to a tension which causes the yarn to become strongly forced against the underlying yarn layers. This may overstress the yarn or impose an undesirable limit upon the attainable pull-off speed.

It is one of the objects of my invention to provide methods and means which compensate such undesired force at least partially for minimizing or virtually eliminating their detrimental effects.

To this end, and in accordance with a feature of my invention, I subject the yarn portion running off the conical-layer coil to an additional force which acts simultaneously with the unwinding pull exerted upon that yarn portion and which is so directed as to have the tendency to lift or throw that yarn portion off the underlying turns of the coil body. The lifting force may be narrowly limited to a preferred location of the coil, or it may be applied in a relatively large range. The magnitude of the lifting force may be varied in accordance with the direction of the running-off position of the yarn; for example the lifting force may be kept greater or smaller at the end of the yarn coil than at the beginning of the yarn content; Depending upon the particular processing involved, it may further be of advantage to make the lifting force variable in time. For example, impulse-like surges of lifting force are sufiicient in some cases. The magnitude of the force pulses, their duration and frequency of recurrence, can be varied for the purpose of controlling and varying the lifting effect. However, the lifting or throwing-off of the yarn may also be aided by a force, such as centrifugal force, that remains constant during the unwinding operation.

According to another feature of my invention, the yarn coil while being unwound in over-the-tip fashion is simultaneously placed in rotation in the sense of the yarn running off the coil body. Such rotation of the yarn supply coil has the effect of imposing centrifugal force upon all of its turns of yarn. However, while the centrifugal forces cancel each other with respect to the closed turn of yarn extending fully about the coil, no such compensation is effective in the yarn portion running off the surface of the yarn body. As a result, the non-compensated component of centrifugal force either suffices to lift the yarn portion off the coil body or appreciably aids in securing the desired lifting action. Consequently, the lifting force need not, or not entirely, be supplied by the rotation of the running-off yarn portion itself, thus relieving this yarn portion of some tension and reducing the pulling force imposed upon the yarn layers of the supply coil. At the same time, the balooning tendency of the runningoif yarn portion is likewise diminished. As a result, the take-off conditions occurring at very high take-ofi speed remain as moderate as would normally correspond to a much lower take-off speed. Consequently, by virtue of the above-mentioned rotation of the supply coil being unwound over the tip, the expedients and devices normally used only for lowtake-oif speeds becomes also applicable for high take-off speeds.

The rotating speed of the supply coil is preferably so chosen that the yarn portion being pulled off need perform only a few or no rotations about the coil body. Due to the conical position of the yarn turns, a given take-off speed of the yarn does not correspond to a fixed, uniform speed of coil rotation for all yarn positions relative to the coil body. For best performance, it is rather necessary for the unwinding of a given length of yarn, to use a different speed of coil rotation at the moment when the yarn runs olf the coil body at the base of the cone, that is, at the largest coil diameter, than at a mornent when the yarn is running off the tip area of the cone. The tip diameter and the base diameter of a conical layer may have a ratio of about 1:2. A considerable improvement of the take-off conditions is obtained if the rotating speed of the supply coil is approximately adapted to the larger diameter of the coil body; but the speed may also be adjusted to a somewhat lower value, that is, it may be rated between the speeds corresponding to the respective base and tip diameters of the conical yarn layers. The difference in length resulting from the difference of the diameter is then still compensated within a few rotations of the coil, and the yarn is then hardly stressed by ballooning.

Another way of determining the proper rotating speed for the supply coil is to make it correspond to the median takeoff speed of the yarn. This median value corresponds to the total length of a conical layer of yarn in forward and reverse direction relative to the number of the turns that form the conical yarn layer. The Value thus determined may be taken as the median value for calculating the proper rotating speed of the supply coil.

It is further of advantage to stop the rotation of the supply coil in the event of yarn breakage and whenever it is necessary for other reasons to stop taking yarn from the supply coil as is the case, for example, when the yarn package on the take-up spool has reached the desired size so that the take-up winder drive must be arrested for removing the completed spool.

Aside from determining the proper rotating speed of the supply coil and setting it manually, this speed of rotation, according to another feature of my invention, may be automatically adjusted simultaneously with, or in dependence upon, the rotating speed of the yarn-guiding drum or other drive that actuates the take-up spool to which the yarn from the supply coil is being supplied. Another way of automatically controlling the rotating speed of the supply coil is to make this speed dependent upon the yarn tension at a given location between supply coil and take-up spool. For example, the rotating speed of the supply coil may thus be controlled or regulated in dependence upon the yarn tension occurring at the first yarn-guiding member following the supply coil. For obtaining particularly great take-01f speeds, it is also possible, in conjunction with the present invention, to provide auxiliary means for preventing or minimizing ballooning, as have been proposed elsewhere.

The foregoing and other objects, advantages and features of my invention will be apparent from, and will be mentioned in, the following description in conjunction with the embodiments illustrated by way of example on the drawings in which:

FIG. 1 shows schematically and in front view a portion of a multi-station winding machine for producing crosswound yarn packages, also called cheeses, from spinning cops;

FIG. 2 is a partial and schematical side view of the same machine;

FIG. 3 illustrates schematically a front view of another yarn-package winding machine provided with three yarnunwinding devices of respectively different designs;

FIG. 4 is a partial and partly sectional View of another embodiment of a yarn-unwinding device; and

FIG. 5 is a partial and sectional view of a further embodiment of such a device.

Referring to the coil-winding machine according to FIGS. 1 and 2, the shaft 2a of a number of coaxial yarn-guiding drums :2 is journalled in the machine frame structure 1. Each individual winding station of the machine is provided with a take-up spool 3 whose periphery rests upon the surface of the appertaining guiding drum 2. Each take-up spool 3 is journalled in a frame structure 3a pivoted at 3b to the machine frame 1. During rotation of the drum shaft 2a each take-up spool is entrained by friction caused by the combined weight of takeup spool 3 and journalling frame 3a. In this manner each individual take-up spool is driven at constant peripheral speed regardless of the diameter of the body of yarn that is being built up on the spool.

The lower portion of the machine frame comprises a beam 4 which carries respective mandrels 5 on which the yarn supply coils 6 are speared up. The yarn F passes from each supply coil 6 through a yarn tensioner 7 and past a yarn guard or feeler 8 onto the yarnguiding drum 2 through whose guiding groove, during rotation, passes the yarn onto the take-up spool 3 while reciprocating the yarn back and forth along the spool to produce a cross-wound package of yarn.

The tensioners 7 are mounted on a carrier arm 9 which extends along all winding stations. Mounted on the machine frame structure 1 is a motor 10 which drives the drum shaft 2a at normally constant speed through a V-belt

transmission comprising sheaves

11, 13 and an endless belt 12. The motor 10 also drives a control shaft 14 through another V-belt transmission. Shaft 14 is journalled on the structure .1 and carries for each winding station a cam disc 29 coopeerating with a cam-follower lever 15. The yarn guard 8, pivoted at 8a, is joined with a latch arm 16. Normally the tip portion of guard 8 rests against the yarn F, and the lever 16 then occupies the illustrated inactive position. In the event of yarn breakage, however, the guard 8 turns clockwise into the dotand-dash position so that the arm 16 places itself against an angular portion 15a of the follower lever 15, as is also shown in FIG. 2 by dot-and-dash lines.

Due to the continuous rotation of cam disc 29, the right-hand end of follower lever 15 is alternately lifted and lowered; but as long as the lever portion 15a is not latched by arm 16, this merely causes the lever 15 to rotate idly about its pivot 15b mounted on a linking rod 30. When the angular portion 15a of lever 15 abuts against latch arm lever 16, which takes place when lever 16 has turned clockwise in response to yarn breakage, then the pivot 15b of lever 15 is lifted by rotation of cam 29 so that linking rod 30 is moved upwardly with the effect of lifting the journalling frame 3a with the takeup spool 3, thus disengaging the spool 3 from the rotating drum 3 whereby the spool is stopped. At the same time, the lever 15 entrains a lock 17 at the forked upper end of a lifting rod 18 whose lower end is linked to a lifting lever 19. Lever 19 is linked to a bearing sleeve 20 so that the sleeve is lifted and lowered together with red 18. The mandrel 5 for receiving the supply coil 6 is journalled in the bearing sleeve 20 by means of a man drel shaft 21 whose lower end carries a friction disc 22 which can cooperate with a driving disc 23 only when sleeve 20 and disc 22 are in the illustrated lowered position.

The driving disc 23 is adjustably seated on a shaft 25 driven from motor 10 through a V-

belt transmission

26, 27, 28. Consequently, the drive shaft 25 for the mandrels is connected with the yarn-guiding drums 2 through the

transmission

11, 12, '13 so that the revolving speed of each mandrel 5 and the rotating speed of the guiding drums 2 maintain a definite ratio.

Also mounted on shaft 25 is a double flange 31 to co operate with a control lever 32. Turning the lever 32 about its pivot 32a causes displacement of the shaft 25 toward the left or right. The lever 32 has an arm 33 which can be arrested by means of a set screw entering into a selected one of a series of holes 34 so that any ad justed setting of lever 32 in shaft 25 cannot change accidentally. The driving discs 23 are fastened on shaft 25 by respective set screws 24. During the above-mentioned displacement of shaft 25 in the axial direction, all driving discs 23 are displaced simultaneously. The available range of displacement is kept so large that by means of the same device either a rotation of the mandrels 5 in the clockwise direction or in the counterclockwise direction can be set for a given direction of rotation of the driven motor. This makes the coil-winding machine suitable for use of supply coils with right-hand twist of the yarn as well as for COils with left-hand twist.

Pivotally mounted above the top of each driven friction disc 22 is a brake lever 37 whose spacing from the disc is adjustable by means of a set screw 38 and a spring 39. If, in the event of yarn breakage or exhaustion of the supply coil, the rod 18 is raised in the manner described above, thus lifting the lever 19 and the bearing sleeve 20, then the friction disc 22 moves away from the driving disc 23 and place itself against the brake lever. As a result, the supply coil is braked to standstill together with the above described stopping of the take-up spool.

When starting the operation of the machine and while the supply coil is at first still at rest, the yarn will first rotate about the coil 6 and thus form a balloon. By displacing the disc 23 or displacing the shaft 25, such ballooning can be minimized until the removal of yarn from the coil due to rotation of the yarn is equal to the pullingcfi speed of the yarn determined by the rotating speed of the yarn-guiding drum 2. However, the device also permits adjusting a smaller speed corresponding to the outer diameter of the supply coil.

In the latter case, the balloon of rotating yarn forming itself has a considerably slower speed of rotation. Due to the fact that the supply coil participates in the rotation, there occurs a centrifugal force which can make itself felt only at the free end of the yarn with the effect that the yarn is flung away from the coil body or, at least, can be lifted away from that body more easily than when the coil is standing still. As a result, the pulling force which the yarn portion exerts upon the yarn body of the supply coil is considerably reduced and the pull with which the take-up spool is wound up is likewise reduced.

The multi-station coil-winding machine illustrated in FIG. 3 is generally similar to the one described above with reference to FIGS. 1 and 2 but is equipped with three winding stations denoted by A, B and C, of respectively different design.

In winding station A, the supply coil6 is not connected with a drive. The mandrel 5 of the coil 6, however, is journalled in anti-friction bearings so that it can readily rotate when the slightest pull is applied to the yarn. When starting the unwinding operation, a balloon of yarn is formed which imposes a force upon the supply coil as the speed of ballon rotation increases. This has the effect that the supply coil commences to participate in the rotating motion. In this case too, the shut-off device for the take-up spool drive may serve to actuate a brake in the manner described with reference to FIGS. 1 and 2. As a result, the momentum inherent in the supply coil is absorbed by braking in the event of yarn breakage or stoppage of the wind-up drive.

The design of winding station B in FIG. 3 is such that no rotation of the supply coil 6 takes place. A shell 41 of electrically conducting material, for example metal, is mounted on, and insulated from, the mandrel 5. This shell is electrically charged by applying a suitable potential, with the effect that the yarn is lifted off the body of the supply coil by the electric field in order to make the yarn more easily run off the yarn body. Instead of a metallic cylinder, the shell may also consist of dielectric material charged electrostatically. According to another modification, the cylindrical shell may besubstituted by one or several rods which cause the yarn to be lifted off the yarn body at least partially by applying a sufliciently high electric voltage between the rods and the mandrel.

In the embodiment of the unwinding device incorporated in winding station C of FIG. 3, a suction nozzle 43 has a nozzle slot extending longitudinally along the body of yarn. Instead of a single suction nozzle, several such nozzles may be mounted on a circle about the mandrel axis. By the effect of the suction current, the yarn is likewise easily lifted off the coil body, or the lifting effected by the pull exerted upon the yarn is considerably assisted, thus greatly improving the running-off conditions.

FIG. 4 shows only one of the supply-coil devices of a multi-station winding machine otherwise similar to that described with reference to FIGS. 1 and 2.. According to FIG. 4 the supply coil 6 is seated upon a stationary mandrel 45 fastened to the beam 4 of the machine frame structure. The device is provided with a ball bearing 46 mounted inconcentric relation to the mandrel 45 and carrying a fan wheel 47 which has a friction disc 48 en gaged by and driven from the driving disc 23 of shaft 25. A hood 49 takes care of passing the current of air from above along the coil 6 toward the fan wheel before the air passes through the loWer end of the hood. In this case, too, the air current has the tendency to lift the yarn away from the body of coil 6 because the yarn, under the effect of the descending air current, bulges slightly and thus moves away from the body.

In the embodiment shown in FIG. 5, the supply coil 6a. has a core or quill 6b provided with a number of longitudinal slots 53. The coil is placed upon a hollow mandrel 51 which is connected to a supply of compressed air. During operation, a current of air passes through the hollow core, as indicated by the arrow L, and passes out of those slots 53' that remain or become uncovered. The hollow core, if not closed at one end, is preferably provided with a. stopper such as 'aball-shaped handle 54. The current of air blown from below through the coil body and passing through the long slots entrains the yarn and lifts it away from the yarn body, thus producing the improved running-off conditions desired.

In devices according to the invention, the running-0H speed of the yarn can be regulated manually. However, it is also possible to measure the yarn tension at the first yarn-guiding structure contacted by the yarn coming from the supply coil and to use the amount of tension for electrically controlling the rotating speed of the supply coil and thus the lifting force acting upon the yarn. For this purpose, a change-speed mechanism of any suitable other design may be used in lieu of the

transmission

26, 27, 28, or the displacement of the control shaft 25 can be effected by means of an electromagnet which acts upon the lever 33 and is controlled in dependence upon the yarn tension as mentioned above.

It will be obvious to those skilled in the art, upon a study of this disclosure, that the invention is not limited to the illustrated embodiments, but may be given various other modifications. The invention is applicable with individual winding stations as well as in multi-station machines and also in fully automatic coil-winding machines.

I claim:

1. The method of unwinding conical yarn-layer coils at relatively high yarn take-off speeds which comprises unwinding the yarn from the successive conical layers of the yarn body of the coil by pulling the yarn axially upward over the coil tip and simultaneously axially rotating the coil to subject said yarn portion at the surface of the yarn body to an aiding force having an upward component tending to lift said yarn portion off the underlying conical yarn layers in coaction with the lifting force component of the pull, the rotating speed of said coil being such that the peripheral speed of said surface is less than the linear take-01f speed of the yarn whereby said aiding force is smaller than required to cause by itself such lifting of said yarn portion.

2. The method of unwinding conical yarn-layer coils at relatively high take-off speeds which comprises unwinding the yarn from the successive conical layers of the yarn body of the coil by pulling the yarn axially upward over the coil tip to form a balloon of the yarn, simultaneously axially rotating the yarn coil to subject the yarn portion being pulled off to a lifting force of generally radial and upward direction tending to move said yarn portion at the surface of the yarn body away from the underlying conical yarn layers, and varying the lifting force during unwinding from a higher magnitude at the start of the unwinding operation toward a lower magnitude at the end of said operation, the rotating speed of said coil being such that the peripheral speed of said surface is less than the linear take-off speed of the yarn.

3. The method of unwinding conical yarn-layer coils at relatively high take-off speeds and simultaneously rewinding the yarn onto a take-up spool, which comprises unwinding the yarn from the successive conical layers of the yarn body of the coil by pulling the yarn axially upward over the coil tip to form a balloon of the yarn, and simultaneously imparting an axial rotating motion to the coil about the coil axis and in the direction of the running-olf movement of said yarn from said coil, imparting a constant peripheral speed to the take-up spool, and maintaining a predetermined ratio between the rotational speed of the coil and the peripheral speed of the take-up spool, whereby the yarn portion being pulled off the coil surface is subjected to a controlled centrifugal force tending to lift said portion 013? said surface without excessive stress in the yarn being caused by the balloon formation, said peripheral speed of the coil having a speed smaller than that of said running-01f movement.

4. The method of unwinding conical yarn-layer coils at relatively high take-off speeds and simultaneously rewinding the yarn onto a take-up spool, which comprises unwinding the yarn from the successive conical layers of the yarn body of the coil by pulling the yarn axially upward over the coil tip to form a balloon of the yarn, and simultaneously imparting an axial rotating motion to the coil about the coil axis and in the direction of the runningofi movement of said yarn from said coil, imparting a constant peripheral speed to the take-up spool, and maintaining a predetermined ratio between the rotational speed of the coil and the peripheral speed of the take-up spool, whereby the yarn portion being pulled off the coil surface is subjected to a controlled centrifugal force tending to lift said portion off said surface without excessive stress in the yarn being caused by the balloon formation, said peripheral speed of said coil corresponding substantially to that of said running-off movement at the largest diameter of the conical yarn layer.

5. The method of unwinding conical yarn-layer coils at relatively high take-off speeds and simultaneously rewinding the yarn onto a take-up spool, which comprises unwinding the yarn from the successive conical layers of the yarn body of the coil by pulling the yarn axially upward over the coil tip to form a balloon of the yarn, and simultaneously imparting an axial rotating motion to the coil about the coil axis and in the direction of the runningoif movement of said yarn from said coil, imparting a constant peripheral speed to the take-up spool, and maintaining a predetermined ratio between the rotational speed of the coil and the peripheral speed of the take-up spool, whereby the yarn portion being pulled off the coil surface is subjected to a controlled centrifugal force tending to lift said portion off said surface without excessive stress in the yarn being caused by the balloon formation, and varying the rotating speed of the coil in dependence upon the yarn tension of said yarn portion.

6. A yarn winding machine, comprising a take-up winder for producing a yarn package from the yarn of supply coils of the conical-layer type, a holder for accommodating such supply coil, said holder being spaced from said winder, yarn guiding means defining a yarn path from said holder to said winder for unwinding the supply coi'l on said holder by pulling the yarn axially upward over the tip of the supply coil due to pull exerted by said winder, and additional force means having an active range near said holder and having a force acting radially outwardly upon the yarn portion being pulled axially upward off the coil, said force having at said holder a direction tending to lift said yarn portion away from the underlying conical yarn layers during operation of said winder.

7. In a winding machine according to claim 6, said force means comprising a drive means for rotating the yarn coil, and a. pneumatic device having an airflow path near said holder for entraining said yarn portion away from said underlying conical layers.

8. A yarn winding machine, a comprising a take-up winder for producing a yarn package from the yarn of supply coils of the conical-layer type, a holder for accommodating such supply coil, said holder being spaced from said winder, yarn guiding means defining a yarn path from said holder to said winder for causing said winder to unwind the supply coil on said holder and form a balloon in the yarn by pulling the yarn over the tip of the supply coil, said holder being rotatable about its axis, and drive means connected with said holder and adapted for axially rotating said holder during unwinding operation in the direction of the running-off movement of the yarn portion being unwound and at a coil peripheral speed less than said running off movement, whereby said yarn portion is subjected to centrifugal force tending to lift it away from the underlying yarn layers.

9. A winding machine according to claim 8, comprising yarn-absence responsive feeler means, and drive control means connected with said drive means and with said feeler means for stopping rotation of said coil holder upon occurrence of yarn breakage and yarn exhaustion.

10. A winding machine according to claim 8, comprising a winder drive connected with said take-up winder for operating said winder, and transmission means conmeeting said winder drive with said drive means, whereby (the rotation of said coil holder has a given relation to the speed of said winder.

11. A winding machine according to claim 8, comprising stop means for arresting said winder, drive control means interposed between said drive means and said coil holder for stopping the rotation of said holder, yarn-absence responsive feeler means disposed along said yarn path and connected with said stop means and with said drive control means for stopping said winder as well as said coil holder upon occurrence of yarn breakage and exhaustion.

12. A winding machine according to claim 8, comprising a normally inactive brake for arresting said coil holder, yarn-absence responsive feeler means disposed along said yarn path and connected with said drive means for stopping said drive means and actuating said brake to arrest said coil holder upon occurrence of yarn breakage and exhaustion.

13. A multi-station yarn-winding machine, comprising in each of its winding stations a take-up winder for producing a yarn package from the yarn of supply coils of the conical-layer type, a holder for accommodating such supply coil, said holder being spaced from said winder, yarn guiding means defining a yarn path from said holder to said winder for unwinding the supply coil on said holder and forming a balloon in the yarn by causing said winder to pull the yarn axially upward over the tip of the supply coil, said holder in each winding station being rotatable about its axis and having a gear means for axially driving said holder; a drive shaft extending along a plurality of winding stations and having respective driving gears for driving said respective gear means, each of said stations having control means for coupling and uncoupling said gear means relative to one of said respective driving gears, and each station having yarnabsence responsive feeler means connected with said control means of the same station for uncoupling said gear means from said driving gear in the event of absence of yarn in said path.

14. A winding machine according to claim 13, comprising a winder drive having a drive shaft and a plurality of drive members coaxially mounted on said drive shaft to be driven simultaneously, said drive members being engageable with said respective take-up winders, winder control means for coupling and uncoupling said winders from said respective drive members, each of said feeler means being connected with said drive control means in the same winding station for stopping said winder of said station in response to absence of yarn, whereby said coil holder and said winder in each station are stopped by response of said feeler.

15. A winding machine according to claim 14, comprising transmission means of adjustable transmission ratio connecting said drive shaft with said control shaft for driving the latter in an adjusted speed relation to said drive shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,840,262 Simonson et al Jan. 5, 1932 2,251,311 Wylde et a1. Aug. 5, 1941 2,574,455 Abbott Nov. 13, 1951 2,603,938 Rodgers July 22, 1952 2,605,982 Miller Aug. 5, 1952 2,628,579 Sutphin Feb. 17, 1953 FOREIGN PATENTS 659,908 France Feb. 11, 1929 1,146,746 France May 27, 1957