US2676618A - Mechanism for actuating thread twisting means in looms - Google Patents

Description

April 27, 1954 I E. PFARRWALLER 2,676,618

MECHANISM FOR ACTUATING THREAD TWISTING MEANS IN LOOMS Filed Aug. 5, 1950 INVENTQR ATTORNEY Patented Apr. 27, 1954 OFFICE MECHANISM FOR ACTUATING THREAD TWISTING MEANS IN LOOMS Erwin Pfarrwaller, Winterthur, Switzerland Application August 5, 1950, Serial No. 1775787 6 Claims.

The present invention relates to an improved mechanism for actuating shedding cards and more particularly thread twisting means inlooms for weaving.

The present application is a continuation-inpart of my co-pending application, Serial No. 12,948, filed March 4, 1948, which matured on July 8, 1952, into Patent No. 2,602,470.

It is an object of the invention to provide a mechanism for twisting warp threads in a loom for weaving by means of cards preferably having the configuration of rings with teeth on their circumferences which mesh with teeth of pinions which are rotated for actuating the cards. The present invention is particularly directed toward an improved driving mechanism for operating the aforesaid pinions to produce a pre-determined pattern of motions of the twisting rings.

The mechanism according to the invention comprises a shaft which is continuously rotated,

preferably by the same source of power which operates the loom, cams having a plurality of individual active surface portions and bein preferably exchangeably mounted on said shaft for producing the desired pattern of movement of the pinions and twisting rings, and operating means comprising cam. followers engaging said cams and means connected with said cam followers a-nd operatively connected with said pinions for moving the twisting rings in consecutive steps in accordance with the configuration of said cams. The aforementioned operating means preferably comprise a bellcrank leverlike member having a cam follower on each arm, said followers individually engaging the surfaces of a pair of like cams fixed on the aforementioned shaftin offset relation, andv having a toothed surface on one arm engaging a pinion which is concentrically fixed to a gear wheel having teeth meshing with those of one of said pinions. The same pair of cams may be engaged by a second bellcrank lever which operates a second card disc through a second train of gears. Instead of providing two followers and two cams, each lever may have only one follower actuated by one cam, the cam being in the form of a groove receiving the follower or the follower may be pressed to the by the action of a spring connected with the lever and a stationary part of the loom.

Such arrangements are conventional and their use no departure from the scope of the present invention.

The mechanism according to the invention does nct require means for translating the continuous rotation of a shaft, which may be rotated by the loom drive, into an intermittent rotation-of another shaft, although it may be modifled to embody such means.

The cams preferably have surface portions between motion producing portions for suspending motion of the twisting means between successive actuations during desired periods of time.

The mechanism according to the invention is primarily for the purpose of twisting adjacent warp threads for binding weft threads, for example, at the edge of a fabric for producing a border. According to the design of the cams, the direction of twist may be reversed after each or a plurality of twists and, by interposing circular cam portions concentric with the axis of rotation of the cams between motion producing cam portions, operation of the twisting means can be suspended after each twist for a pre-determined duration. By proper design of the cams, this duration may, for example, after a desired number of twisting operations, be so great as to permit several weft insertions before making the next twist. By using appropriately shaped cams, a great variety of binding patterns can be obtained.

Further and other objects of the present invention will be hereinafter set forth in the accompanying. specification and claims, and are shown in the drawings which, by way of illustration, show what I now consider to be preferred embodiments of the invention.

In the drawings:

Fig. 1 is a diagrammatic side elevation of a loom provided with a warp thread twisting mechanism according to the invention, but not showing the actuating means for the twisting mechanism.

Fig; 2 is a large scale side view, partly in section, of a, mechanism according to the invention for actuating the twisting discs or rings;

Fig. 3 is a view in axial direction of a pair of cams forming part of the mechanism according to Fig. 2;

Fig. 4 is a diagrammatic showing of warp threads twisted about weft threads in a pattern produced by the cams shown in Fig. 3;

Fig. 5 is a View in axial direction of a pair of cams shaped differently from those shown in Fig. 3 for producing the pattern illustrated in '7v is a large scale view of a portion of one cam of the pair shown in Fig. 5;

Fig. 8 is a view in axial direction of a further modification of a cam pair for producing the pattern shown in Fig. 9.

Like parts are designated by like numerals in all figures of the drawings.

As shown in Fig. l, the warp threads 1 move from warp beam 6 over a tensioning beam 20 where they separate to form an upper shed 2| and a lower shed 22, through eyes 24 of the heddles I0, and reed 25 to the apex 26 of the shed where they form the fabric 9 by interlacing with the weft threads I8. The fabric passes over a guide beam 21 and is then wound on a fabric beam 8.

Binding threads 28 and 29 move from spools 30 and 3| over the tensioning beam 20, individually through eyes 33 and 34 of a twisting ring 35, through the read 25, and to the apex 2B of the shed, wherefrom they are wound, intertwined with fabric 9, on the beam 8.

The twisting rings 35 are supported in a frame 31. The rings are provided with teeth 38 and individually engage the teeth of pinions 39 and 40 which are keyed to shafts 4| and 42, respectively.

Fig. 2 illustrates a mechanism according to the invention for actuating the shafts 4| and 42 for producing the desired warp thread twisting pattern. Elbow r bellcrank levers I 50 and I each having two arms, are positively oscillated about stationary pins I54 and I55, respectively, in the direction of double arrows I55, I51 by means of substantially circular cams 200 and 20I which are eccentrically mounted on shaft I 45 and respectively engaged by rollers I65 and IE6 on lever I 50 and rollers I61 and I68 on lever I5I. The oscillating movement of levers I50 and I5I is transferred by the toothed end portions I58, and I59, respectively, of the upright arms of the levers to double tooth wheels I60, I5! and I92, I63, respectively, and therefrom to pinions I 2| and I22, respectively, on shafts 4| and 42. Shaft I45 may be driven intermittently in the direction of arrow I23 by a Geneva gear as shown in Patent No. 2,602,470. Shaft I45 may also be driven continuously, for example by the loom drive, which also drives the picking mechanism.

In the operating position shown in Fig. 2, lever I5I changes its movement from that indicated by arrow I69 to that of arrow I whereby the rotation of shaft 42 is reversed from arrow I 1| to I12. Lever I50 moves in the direction of arrow I13 and shaft 4| rotates in the direction. of arrow I14. Due to the relatively displaced positions of levers I50 and I 5| reversal of rotation of shafts 4| and 42 does not occur at the same time.

If shaft I45 is driven continuously in the same direction of rotation, cam discs 200 and must be provided with active cam surfaces composed of a plurality of individual curve portions. Figures 3, 5, 8 illustrate three differently shaped cam pairs for producing difierent twisting patterns. The individual cam portions which pro-' duce catuations of the twisting discs or rings are separated in Figures 3, 5, 'i', 8 by radial lines a to n. The mechanism is at a standstill whenever the cam followers I65, I66 and I61, I68 reach a portion of the cam surface adjacent to the in' portion, the elbow levers I50 and I5I make par tial swings, depending on the length of the cam portion between two radial lines and the gear wheels I60, I6I and I62, I63 are rotated and effect rotation of shafts 4| and 42, respectively.

With a configuration of the cam discs 200 and MI as shown in Fig. 3, the card discs 35 are rotatecl through 180 when shaft I rotates through an angle between any two consecutive radii a. to n.

Fig. 4 is a diagram indicating the twisting pattern produced by the cams shown in Fig. 3. Twisting is reversed after six actuations of a twisting ring, when an elbow lever is actuated by a cam portion of smallest radial extent, as at radius a, and by a cam portion of greatest radius, as at 9. At these points, direction of the swinging direction of the elbow levers is reversed. The surface of the cam traversing radial lines a, b, c, d, e, f 9 is symmetrical to the surface traversing lines a, n, m, k, h, g.

When using cams as shown in Fig. 3, two warp threads are twisted about one another and, if the operation of the twisting mechanism is appropriately coordinated with that of the pick ing mechanism of the loom, about a weft thread at each angular movement of shaft I 45 from one radial line to the next following radial line.

By using cam discs of a configuration illustrated in Fig. 5 and designated by numerals 202 and 203, a twisting pattern will be obtained as shown diagrammatically in Fig. 6. In this pattern, twisting is suspended while the cam shaft I 45 moves from radius 0 to radius b and from radius 2' to radius h and, since the speed of shaft I45 is coordinated with that of the picking mechanism, two weft threads I8 will be bound between two consecutive twists of the warp threads. Fig. 7 illustrates a portion of cam disc 202 on a larger scale. When roller I65 abuts the arcuate surface 206 of disc 202 at radius 1, lever I remains at rest until the roller rides up on the cam surface 208 between points 201 and 209, causing clockwise movement of lever I50. A cylindrical cam surface portion 2I0 begins at point 209 and extends to point 2 I I symmetrically to radius 9. This cylindrical surface suspends movement of lever I50 and actuation of the card disc associated therewith. A descending portion 2I2 of the cam curve begins at point 2H and continues at point 2I3 into a circular portion 2 I4 at radius h which portion ends at point 2I5 beyond radius i. This extended circular portion suspends actuation of a twisting ring during the period when shaft I45 moves through the angle enclosed by radii h and i. Thereafter roller I rides down on cam curve portion 2|6 until it reaches point 2I1 ahead at radius is thereby causing a second partial swing of the lever actuated by the cam, this second partial swing having the same direction as the first .partial swing caused by the cam portion 2I2. After a standstill along circular cam curve portion 2|8. the roller rides down further, or inward as seen in Fig. 2, along cam portion 220 between points 2I9 and 22I, causing the actuated lever to make a third partial swing in the same direction as the first two partial swings. The same happens between radii m and n and n and a, as seen in Fig. 5. The twisting rings are rotated through upon each partial swing of the respective levers. the rotation being not reversed as long as a cam follower rides on the cam portions indicated by radii ato g. The swing direction of the leveris reversed at radius g and continues, stepwise, in the reversed direction when the cam follower rides along the cam portions confined between radii 9', h, i, k, m, n, and a. At a the swing motion of the lever is again reversed.

By exchange and use of different cam discs, any pattern of intertwining may be produced. For example, by using cams as shown in Fig. 8, two weft threads may be inserted between twists of difierent directions. This is diagrammatically illustrated in Fig. 9, where the twist is reversed not at g, as in Figs. 4 and 6, but at z. According to this pattern, two weft threads are intertwined between two consecutive twists, and there are only four twists between changes of direction of twist. If only one weft thread were bound in between two consecutive twists, the warp threads would be twisted eight times in one direction before they were twisted in the opposite direction. With the cams shown in Fig. 8, an interval is permitted between consecutive twists in the same, as well as in the opposite, direction. It will be noted that in the pattern according to Fig. 4, the direction of twist is reversed after six twists.

Though the provision of cylindrical portions at the intersections of the cam curve with the radii a to n is desirable, the device would operate also if no such portions were arranged between the active cam surface portions. The eyes 33 and 34 of the twist rings hold the shed open long enough to permit insertion of a weft thread also if no special provisions are made for extending the time during which the shed is wide open.

A considerable advantage of the present invention is that it adapts the weave construction of the twisted threads to the weave construction of the fabric. The distance of the weft thread in the small twisted selvage must be chosen in accordance with the character of the fabric, especially for loose woven patterns like tulle, in that the edge is not to be stiffer than the fabric. A further advantage is that by adapting the weave constructions of both fabric and selvage the length of the twisted warp threads is kept the same as the length of the other warp threads, so that the twisted threads do not need special bobbins but may be wound on the warp beam.

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details of method, design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. In a 100m the combination of a continuously rotating shaft, thread twisting means, operating means connecting said shaft and said twisting means for rotating the twisting means stepwise in either direction; said operating means comprising a bellcrank lever, a cam follower fixed to each arm of said lever, pairs of substantially like cam members fixed on said shaft, one cam member of each pair engaging one cam follower and the other cam member engaging the other cam follower, said cam members having a series of active cam surface portions actuating said lever in consecutive steps, and a mechanism interconnectin said lever and said twisting means for transmitting the motions of said lever to said twisting means.

2. A mechanism for actuating thread twisting means in looms comprising a plurality of rotatable twisting members, a continuously rotating shaft, a pair of cams fixed on said shaft, each cam having a series of individual consecutively effective cam surface portions, a lever for each cam, said levers being engaged by said cams and individually stepwisely actuated by said surface portions to make partial swings upon rotation of the cams through an angle substantially corresponding to one of said surface portions, and a plurality of motion transmitting means individually interconnecting said levers and said members for rotation of the latter upon each partial swing of the respective lever and reversing the direction of rotation of said members upon reversal of the swinging direction of said levers.

3. A mechanism as defined in claim 2, said levers having the configuration of bellcranks individually engaging said cams with one arm, said motion transmitting means being individually connected to the other arms of said bellcrank levers.

4. A mechanism as defined in claim 2, said cams having cylindrical surface portions concentrio with the rotation axis of the cams and individually disposed between two consecutive cam surface portions for suspending actuation of the respective levers between actuations by said cam surface portions.

5. A mechanism as defined in claim 2, said cams individually having two symmetrically shaped and diametrically opposed sides, each side having a series of consecutively acting individual surface portions.

6. A mechanism for actuating a rotatable thread guiding member in a loom, said mechanism comprising a shaft rotating continuously in one direction, substantially circular cam means fixed eccentrically on said shaft, a lever actuated by said cam means, said cam means having a series of individual active cam portions for causing said lever to make a partial swing upon rotation of said cam means through an angle substantially corresponding to one of said surface portions, and a motion transmitting means interconnecting said lever and said member for rotation of the latter upon each partial swing of said lever and reversing the direction of rotation of said member upon reversal of the swinging directing of said lever.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 639,626 Steere Dec. 19, 1899 1,757,947 Snow May 6, 1930 2,083,291 Camps June 8, 1937 2,099,729 Floyd et a1. Nov. 23, 1937 2,399,880 Moessinger May 7, 1946 2,401,452 Banyai June 4, 1946

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