US3124168A

US3124168A - Shuttle picking mechanism for weaving machines

Info

Publication number: US3124168A
Authority: US
Publication date: 1964-03-10
Anticipated expiration: 1981-03-10

Description

March 1954 J. WOHLGEMUTH ETAL 3, 4, 8

SHUTTLE PICKING MECHANISM FOR WEAVING MACHINES 2 Sheets-Sheet 1 Filed Oct. 25, 1961 X mm m U 0 MM u 55 5% A March 10, 1 4 J. WOHLGEMUTH ETAL 8 SHUTTLE PICKING MECHANISM FOR WEAVING MACHINES Filed Oct. 25, 1961 2 Sheets-Sheet 2 l7 emors. JbsE-F MHL ss/gu -m ANS DEMU TH- K [tor/1g.

United States Patent 3,124,168 SHUTTLE PICKENG MECHANISM FOR WEAVENG MACHINES .l'osef Wohigemuth, Snla-Attikon, and Hans Demuth, Winterthur-Tess, Switzeriand, assignors to Sulzer Freres, 8A., Winterthur, Switzeriand, a corporation of Switzerland Filed Oct. 23, 196i, Ser. No. 146,924 Claims priority, application Switzerland Oct. 28, 1960 Claims. (Cl. 139-145) The present invention relates to a picking mechanism for the shuttles in a weaving machine, the picking mechanism being actuated by a resilient torsion rod which is torsionally tensioned prior to each pick, the rod having one end connected to a holding element mounted on the machine frame or forming a part thereof.

In a conventional mechanism of this type, for example, as shown in Patent Nos. 2,777,472 and 2,813,549 one end of the torsion rod is fixed.

In the mechanism according to the invention one end of a torsion spring rod is revolvably connected to a support element and an abutment is provided which acts between the first end of the torsion spring rod and the support element when the second end of the rod is revolved for tensioning the rod, the rod being rotatable at least through a predetermined angle relative to the support in the opposite direction after expansion of the rod.

The arrangement according to the invention is of particular advantage in a mechanism wherein the rotation of the expanding torsion rod is braked. The brake usually must be so adjusted that it becomes fully effective only after rotation of the picking lever actuated by the torsion spring rod through a predetermined angle to prevent the brake to unduly reduce the acceleration of the picking lever and of the shuttles by the expanding torsion spring rod. The brake is effective during the rotation of the expanding torsion rod only, i.e. acts in one direction only. If, for example, because of small breaking strength of the weft thread, the torsion must be reduced to reduce the shuttle speed, i.e. the torsion rotation of the rod prior to each pick must be reduced, the position of the expanded rod is in a zone wherein the brake is not fully effective. If, in this case, one end of the torsion rod is fixed, as in the conventional torsion rod actuated shuttle picking mechanisms, the rod is tensioned in the opposite direction after rotation through the fully expanded position whereupon it expands once more and rotates through an expanded position to be tensioned once more in the original direction, and so on. The rod is subjected to torsional oscillations which occur outside of the angle within which the brake is fully effective and which are insufficiently damped. This may cause knocking of the movable parts of the shuttle picking mechanism.

In the arrangement according to the invention inertia forces can continue to rotate the torsion rod beyond its r torsionless position without changing the direction of rotation of the expanded rod until the rotation angle extends into the angle at which the brake is fully effective. This makes it possible to reduce the initial torsion without changing or adjusting the brake.

In an embodiment of the invention at least two abutments are provided on the circumference of the torsion rod in equally spaced relation and acting in the same direction for stopping rotation of one end of the torsion rod when the second end is revolved for tensioning the rod. This symmetric arrangement of the abutments relieves the element supporting the torsion rod and avoids unsymmetric forces acting thereon.

In another embodiment of the invention equally spaced teeth are provided on the circumference of the torsion rod and in the corresponding part of the support element whereby the width of the gaps between the teeth is greater than the thickness of the teeth. For example, every other tooth may be omitted in a normal gear-tooth system wherein the space between two teeth corresponds to the thickness of a tooth so that, after expansion of the torsion rod, the rod can continue to rotate without tension through an angle corresponding to the space between two teeth of the normal gear-tooth system.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing wherein:

FIG. 1 is a perspective illustration of a torsion-rod actuated shuttle picking mechanism of a weaving machine provided with means according to the invention for supporting the torsion rod.

FIG. 2 is a longitudinal sectional view of torsion-rod support means according to the invention, the section being made along line II-II of FIG. 3.

FIG. 3 is an end view of the support means shown in FIG. 2.

FlG. 4 is a part sectional illustration of a modified portion of a support means according to the invention.

FIG. 5 is a part sectional illustration of another modification of a portion of a support means according to the invention.

Referring more particularly to FIG. 1 of the drawing, numeral 1 designates a torsion rod the right end of which is not visible in FIG. 1 and shown in FIGURES 2 to 5. It is supported by a support means 21, 27 which will be described later and which includes a flange 28 which is made fast on the frame of a weaving machine, not shown. The rod 1 is preferably made in one piece.

A shuttle picking lever 3 has a sleeve portion 3' which is clamped to the left end 1' of the rod 1. A shuttle picking element 4 is pivotally connected to the free end of the lever 3 for picking a shuttle 5 in the direction of arrow 72 through a shuttle guide 33 upon movement of the lever 3 in the direction of the arrow 67. The shuttle guide is composed of a plurality of guide elements mounted on a lay 34 in front of a reed 35. The lay swings as indicated by arrows 36. The shuttle 5 is placed into the position shown in FIG. 1 by means of a lifter 37 which oscillates in the direction of the arrows 41. The shuttle is provided with a thread gripper which is opened by an opener 6 swingable in the direction of arrows 38.

An arm 11 is rigidly connected to the left end portion of the rod 1 and is linked by a link 20 and a pin 30 to the end of an arm of a lever 9 which is swingable on a pivot it). The left portion of the rod 1 between the lever 3 and the arm 11 is preferably thicker and much shorter than the right portion between the arm 11 and the support 21 so that the left portion is practically not twisted, the entire torsion being effected in the right portion. The lever 9 and the link 20 form a toggle joint. The lever 9 supports a roller 17 which follows a cam 12 mounted on a shaft 3. The cam 12 supports a roller 14 following a cam surface 13 of the lever 9. The lever 9 has an arm which is pivotally connected to a piston 16 of a hydraulic brake 15. This brake becomes fully effective at the moment the end 63 of the piston 16 enters a brake chamber 64-. The torsion rod 1 can, therefore, expand and the shuttle picking lever 3 can move through a predetermined angle before the brake becomes fully effective. The shaft 8 supports a bevel gear 42 whose teeth mesh with the teeth of a bevel gear 43 mounted on the main shaft 7 of the weaving machine. The shaft 8 and the cam 12 are continuously driven by the main shaft 7.

Assuming that the right end of the torsion rod is fixed, the mechanism operates as follows:

The mechanism is moved into the position shown in FIG. 1 wherein the toggle joint 9, 20 is in extended position, upon running of the roller 17 on the elevated portion 18 of the cam 12. During this movement the left end of the torsion rod 1 is rotated in counterclockwise direction. The lever 3 is swung in the direction of the arrow 66. Upon subsequent rolling of the roller 14 on tie cam portion 13 of the lever 9 the toggle joint moves in the direction of the arrow 44 and collapses, permitting expansion of the torsion rod 1 and movement of the shuttle lever 3 in clockwise direction. The shuttle to which a weft thread is connected is thereby picked through a shed formed by warp threads, not shown. If the rod 1 is tensioned by a predetermined force, the angle through which the part of the rod 1 to which the arm 11 is connected rotates during expansion of the rod is so great that the brake 15 becomes effective during the expansion rotation of the rod 1. If, however, the initial tension is smaller, the torsionless position of the rod 1 is located within an angle wherein the brake 15 cannot be fully effective. The torsion rod will, therefore, rotate beyond the torsionless position whereby it is tensioned in the opposite direction and insufliciently braked torsion vibrations develop. This may cause knocking, for example, of the roller 17 against the cam 12 approximately at the point 45.

FIGS. 2 and 3 illustrate support means for the right end of the torsion rod 1, affording rotation of the entire torsion rod 1 through a predetermined angle after full expansion of the torsion rod. The right end of the torsion rod is rotatable in a bushing 46 inserted in a flange 26 at the end of a stationary support element 27 and in a plate 21 which is held to the flange 26 by a screw 24. Two

teeth

47 and 48 extend in diametrically opposed position from the end 2a of the rod 1. This end extends into an approximately S-shaped aperture 49 in the plate 21. The aperture 49 is provided with two

abutments

51 and 52. During torsion of the rod 1 the

radial flanks

61, 62 of the

teeth

47, 48 abut against the

surfaces

51, 52, respectively. Upon collapsing of the toggle joint 9, the torsion rod expands. If the initial tension is relatively small, the entire rod including the end 2a can rotate without torsion in counterclockwise direction, as seen in FIG. 3, until entering the angle wherein the brake becomes eflective. Rotation of the torsion rod is thereby stopped and no counter-rotation occurs. The maximal turning angle, which is determined by the

surfaces

51, 81 and 52, 82 and which amounts to about to in the example shown in FIG. 3, must be greater at smaller brake effect of the brake 15 and at smaller rotation of the rod 1, because the torsionless position in which the

teeth

47, 48 begin to leave the

surfaces

51, 52 and in which the reverse rotation begins is angularly the farther from the beginning of the full brake effect the smaller the initial torsion of the rod 1. In any case, it must be avoided that the left end of the torsion rod 1 is tensioned in the opposite position after expansion.

In the embodiment of the invention shown in FIGS. 2 and 3 the plate 21 is provided with a pin 53 which abuts against a screw 32 screwed into the flange 26 whereby the position of the plate 21 and of the

abutments

51, 52 relative to the flange 26 can be adjusted after loosening the bolt 24. An arcuate slot 22 is provided for this purpose in the plate 21, the bolt 24 extending through said slot. The aforesaid adjustment also determines the torsion of the rod 1 which is available for the shuttle picking operation. The rod can be tensioned the more and the shuttle can be picked at greater velocity the greater the breaking strength of the weft thread.

The flange 26 is provided with a protuberance 54 on which a scale 55 is provided which, by cooperation with a mark 56 on the plate 21, indicates the relative posi- 4 tion of the plate 21 and of the flange 26 which can be adjusted by manipulation of the screw 32.

The shuttle picking mechanism shown in FIGS. 2 and 3 is adjusted as follows: The screw 24 is loosened and the

parts

1, 20, 9 and 12 are moved into the position shown in FIG. 1 wherein the toggle joint 20, 9 is extended. The torsion rod 1 is without torsion. Thereupon the screw 32 is screwed into the flange part 26 until the screw abuts the pin 53 and moves the plate 21 around the end 2a of the torsion rod 1 in counterclockwise direction. This causes counterclockwise rotation of the end 2a of the rod 1 and movement of the mark 56 to the right and relative to the scale 55. This adjustment is continued until the

parts

26 and 21 are at a relative angle which corresponds to the desired shuttle speed and to the breaking strength of the weft thread. Thereupon the screw 24 is tightened and the shuttle picking mechanism is ready for operation. Continued rotation of the cam 12 releases the toggle joint and allows the torsion rod 1 to expand whereby the picking lever 3 with the picking element 4 picks a shuttle 5.

If it is desired to change the angular spacing of the

abutments

51, 81 and 52, 82, two adjustable plates 21 may be provided which can be tightened to the flange 26 by the screw 24, one plate forming the

abutments

51, 52 and the other plates the abutments 81, 82. In this way the maximal reverse rotation angle of the expanded torsion rod 1 can be adjusted.

In the modification shown in FIG. 4 the end 2b of the torsion rod 1 is provided with a gear-toothing 57 and the aperture in the plate 21 is provided with a corresponding toothing 58. Both toothings have spaces 60 between the teeth amounting to twice the thickness of a tooth.

The gaps between the teeth are preferably so great that after expansion of the torsion rod and after the shuttle picking operation the teeth 57 do not abut against the surfaces 81, the rod coming to rest prior to such abutment.

In the modification shown in FIG. 5 a pawl is swingable on a pivot 86 mounted on the plate 21. The pawl 85 is pressed by a spring 84 against the circumference of the end portion 20 of the torsion rod 1 which end portion is provided with a tooth 47 having a radial flank abutting against the pawl 85 when the torsion rod is tensioned. The tooth 47 has an inclined surface adapted to push the pawl 85 out of the way of the tooth upon counterclockwise rotation of the torsion rod after expansion. The system shown in FIG. 5 affords unlimited torsionless counterclockwise rotation of the torsion rod.

We claim:

1. A shuttle picking mechanism for weaving machines comprising a torsion spring rod, support means for supporting one end of said rod, means connected to said rod for revolving the second end of said rod for tensioning the rod, and means connected to said rod for picking a shuttle upon release of the tension of said rod, said support means including abutment means stopping rotation of the first end of said rod when the second end of the rod is revolved for tensioning the rod, said support means affording rotation of said rod through at least a predetermined angle in the direction of rotation of the expanding rod.

2. A shuttle picking mechanism as defined in claim 1 wherein said abutment means includes a stationary abutment and an abutment forming part of said rod and adapted to engage said stationary abutment.

3. A shuttle picking mechanism as defined in claim 1 wherein said abutment means includes at least two stationary abutments and two mating abutments connected to said rod, said abutments being equally spaced on the circumference of said rod.

4. A shuttle picking mechanism as defined in claim 1 wherein said abutment means includes a stationary gear toothing, and a gear toothing connected to said torsion rod and meshing with said stationary toothing, the width 5 of the gaps between the teeth of said toothings being greater than the thickness of the teeth.

5. A shuttle picking mechanism as defined in claim 1 wherein said support means includes a stationary part,

and a part forming part of said abutment means and being 5 adjustably connected to said stationary part for adjusting the angular position of said part of said abutment means.

References Cited in the file of this patent UNITED STATES PATENTS Kesselring Dec. 15, 1885 Pfarrwaller Aug. 16, 1955 Pfarrwaller Jan. 15, 1957 Pfarrwaller Nov. 19, 1957