US3865147A

US3865147A - Mechanism for the return movement of heald shafts of a weaving loom

Info

Publication number: US3865147A
Application number: US324531A
Authority: US
Inventors: Jaroslav Lev; Karel Kakac
Original assignee: Individual
Current assignee: Vyzkumny a Vyvojovy Ustav Zavodu Vseobecneho Strojirenstvi
Priority date: 1973-01-17
Filing date: 1973-01-17
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11

Abstract

Mechanism permitting the easy removal of faulty wovenin weft threads on weaving looms which have come to a stop. The mechanism is provided with a sliding gear wheel on a shaft interposed between the drive of the weaving loom and the gears for driving the heald shafts, said sliding gear wheel, after its disconnection from the drive of the weaving loom permitting return movement of the heald shafts by the action of a pressure air piston actuated by the loom attendant.

Description

tates atent n91 llnite Lev et al.

1 1 Feb. 111, 1975 MECHANIISM FOR THE RETURN MOVEMENT OF HEALD SHAFTS OF A WEAVING LOOM [75] inventors: .laroslav Lev; Karel Kakac, both of Brno, Czechoslovakia [73] Assignee: Vyzkumny a vyvojovy ustav Zavodu vseobecneho strojirenstvi, Brno, Czechoslovakia [22] Filed: Jan. 17, 1973 [21] Appl. No; 324,531

[52] 11.5. CI. 139/1 E, 139/56, 139/79, D03c/13/00 [51] Int. Cl. D03d 51/00, D03c 5/00 [58] Field of Search 139/1 E, l R, 55, 56, 66 R, 139/328, 336, 57, 79-81 [56} References Cited UNITED STATES PATENTS 957,724 5/1910 Wyman 139/79 1,883,743 10/1932 Maybach.. 139/1 E 2,421,539 6/1947 Clarke 139/1 E 2,639,732 5/1953 Moessinger 139/1 E 3,095,015 '6/1963 Cuiengnet 139/1 E 3,237,648 3/1966 Grisay 139/1 E FOREIGN PATENTS OR APPLICATIONS 427,915 5/1935 Great Britain 1. 139/79 1,015,605 8/1952 France 139/57 464,722 4/1937 Great Britain..... 139/336 474,669 11/1937 Great Britain 1 139/56 447,700 5/1936 Great Britain 139/66 R 386,174 1/1933 Great Britain 139/1 E Primary Examiner-lames Kee (Chi [57] ABSTRACT Mechanism permitting the easy removal of faulty wovenin weft threads on weaving looms which have come to a stop. The mechanism is provided with a sliding gear wheel on a shaft interposed between the drive of the weaving loom and the gears for driving the heald shafts, said sliding gear wheel, after its disconnection from the drive of the weaving loom permitting return movement of the heald shafts by the action of a pressure air piston actuated by the loom attendant.

3 Claims, 3 Drawing Figures PATENTED FEB] 1 i575 SHEET 2 BF 2 FIG. 3

MECHANHSM FOR THE RETURN MOVEMENT OF HEALID SHAFTS OF A WEAVIING LOOM BACKGROUND OF THE INVENTION The invention relates to a mechanism enabling a return movement of said heald shafts, required for faulty woven in weft treads; the mechanism is particularly advantageous for use with weaving looms with pressure air control.

In the course of weaving, different faults occur in the produced fabric; some of these faults cause the stopping of the weaving loom. This enables the attendant to become aware of the fault, and to care for its removal. Faults caused by a wrong weaving in of weft threads are removed by subsequent removal of weft threads form the fabric. This removal can, for instance, be executed by turning the drive of the weaving loom in the opposite direction; this. however, is not suitable for some types of looms, for instance for looms provided with arrangements for measuring the length of the weft thread.

In any case, the removal of weft threads by manually turning the loom is tedious and laborious. Different servo-mechanisms for this purpose are therefore provided, particularly with drives by electric motors, which are so made that for one impulse of its control by the attendant a movement of the harness corresponding to one revolution of the loom is accomplished.

A drawback of this solution is the relatively high complexity and possibility of a failure of the electric motor of the servomechanism due to possible overload- SUMMARY OF THE INVENTION It is an object of this invention to eliminate, or at least mitigate, these drawbacks by introducing between the drive of the weaving loom and the means for driving the shafts of healds a sliding gear, provided on both faces with clutches for alternate coupling with a shaft and with a core of a free-wheel coupling. The rim of the coupling has a gear with which a rack is in engagement, such rack being connected with the piston of an air cylinder and provided with a stop extension cooperating with resepctive end steps at the opposite ends of its reciprocation.

An advantage of the arrangement according to this invention is its simpicity with respect to known arrangements, and the easy and reliable control of such arrangement, by actuation of a two arm lever and the pressing of a control push button or pedal of a valve.

DESCRIPTION OF THE DRAWING An examplary embodiment of the object of this invention is indicated in the attached drawing, wherein,

FIG. 1 is a schematic elevation partly in section of the entire arrangement;

FIG. 2 is a schematic top view of the arrangement of FIG. 1; and

FIG. 3 is a schematic view in elevation, taken from the line 3 3 of FIG. 2 of the mechanism driving the heald shafts of the loom.

DESCRIPTION OF PREFERRED EMBODIMENT A shaft 2 is shown rotatably supported in a frame I of a weaving loom. A driving gear 3 is fixed to shaft 2, gear 3 meshing with a driving gear (not shown) connected to the drive of the weaving loom. A sliding gear 4 having teeth 5 is freely rotatably and axially shiftably supported upon the shaft 2, the sliding gear 4 having a prolonged hub 6. A circumferential groove 7 is provided on this prolonged hub 6, one end of a two-arm lever 8, supported on a pivot shaft 9, fixed on the frame 1 of the loom, being disposed in sliding arrangement in said groove 7.

The other end of the two arm lever 8 terminates in a handle 10. The sliding gear 4 has in its sides extensions 11 and 12 respectively, extension 1! being on a face of the sliding gear 4 proper, the extension 12 being on the face of the prolonged hub 6. Each of these extensions II and 12 forms one part of two respective claw clutches. The second part of one claw clutch forms a recess 13, provided in the collar 14 of the shaft 2. A recess 15 is provided in the face of the core 16 of a free-wheel coupling or over-running clutch 17; core 16, which is freely rotatably supported on the shaft 2, forms the second part of the second claw clutch. The core 16 has on its surface a set of recesses 18 housing rollers 19 for engagement with the rim 20 of the freewheel coupling 17. The rim 20 has on its external circumference a gear 21, engaging with a rack gear 22. A piston rod 23 is fixed to the rack 22, the piston 24 affixed to rod 23 being slidable in an air cylinder 25 fixed on the frame 1 of the weaving loom. A coil compression or return spring 26 is provided in cylinder 25 in order constantly to urge the piston 24 to the left (FIG. 2).

The sliding gear 4 is in constant engagement with a gear 27 which, together with another gear 28, is fixed on a shaft 29 which is rotatably supported on the frame ll of the weaving loom. The gear 28 meshes with a further gear 30, fixed on another shaft 31, which is also rotatably supported on the frame 1. A set of earns 32 for the control of the heald shaft is fixed on the shaft 31.

A stop extension or dog 33 on the rack 22 is adapted for engagement with two spaced

end stops

34 and 35 on the frame 1 to limit the length of stroke of the piston 24 in the air cylinder 25.

In FIG. 3 there are shown

heald shafts

36 and 36 which are slidingly mounted on the frame I of the loom. Pull rods are attached to the heald shaft 36 being designated 37 and 38 respectively. Such pull rods in turn rigidly connected to double-

arm levers

39 and 40, as shown. The double-arm levers 39 40 are pivotally mounted upon fixed pivot pins 4i and 42 respectively, which are connected to the frame 1 of the loom. The opposite end of the double-arm lever 39 is pivotally connected to a link 43 which is connected to a cam follower roller 44 which coacts with the cam 32. Extending from the cam follower roller 44 is a bent link 46 which extends to the second, upstanding arm of the double-arm lever 40. It will be apparent that as the shaft 31 rotates, the cam 32 rotates therewith, thereby causing the cam follower roller 44 and the

links

43 and 46 connected therewith to reciprocate and thus to oscillate the respective double-

arm levers

39 and 40. This causes the heald shaft 36, for example, to rise while the heald shaft 36' is descending, and vice versa.

The disclosed mechanism operates as follows:

In the course of weaving, the required power for the control of the heald shafts is transmitted via a driving gear (not shown) of the weaving loom to the transmission gear 3 (FIG. 2) and therfrom by the shaft 2 via a first claw clutch made up of the recess l3 and the extension ll, to the sliding gear 4 the extension ll of which engages the collar 14 of the shaft 2. The free end of the two arm lever 8 opposite the handle is thereby in the dash line position ll. The rotating motion of the sliding gear 4 is further transmitted to the counter gear 27 which rotates together with the gear 28. The rotation of the gear 28 is transmitted via a further gear 30 and the shaft 31 to a set of cams 32 which control the heald shafts (not shown).

lf due to some fault in the course of weaving-in the weft thread the weaving loom has been stopped and one or more recently woven-in weft threads have to be removed from the fabric, the attendant sets the two arm lever 8 by means of the handle 10 into the solid line position I. The second end of the two arm lever 8 engaging into the circumferential groove 7 shifts the sliding gear 4 into its second extreme position on the shaft 2, whereby the extension 11 of the claw clutch is disengaged from the recess 13 in the collar 14 and the extension 12 on the face of the hub 6 of the sliding gear 4 comes into engagement with the recess 15 in the core of the free-wheel coupling 17. The sliding gear 4 remains even after this shifting in constant driving engagement with the counter gear 27 and, by way of it, through the

further gears

28 and 30, with the set of cams 32.

After setting of the two arm lever 8 into position I, the attendant presses the push button or the pedal of a three-way valve (not shown) of common design interposed in the pressure air circuit of the loom. The pressure air passes via a tubing (not shown) to the left end of the air cylinder above its piston 24. A movement of the piston 24 to the right is caused by the action of this pressure air, thus compressing the return spring 26 and simultaneously shifting the piston rod 23 with the rack 22 from its left extreme position into the other right, one. The stop dog 33 of the rack 22 then rests against the end stop 35, limiting the length of the stroke of the piston 24. In the course of an axial movement of the rack 22, to the right (FIGS. 1 and 2), the rim 20 of the free-wheel coupling 12 is turned clockwise (FIG. 1). In the course of the first portion of such rotation of the rim 20, the rollers 19 are caused to leave to a certain extent the system of recesses 18 of the core 16 to be clamped between the internal circumference of the rim 20 and the core 16 of the free wheel coupling 17. The rollers 19 transmit thereafter in the following phase of such rotation of the rim 20 the torque from the rim 20 to the core 16. By way of the claw clutch formed by the recess 15 and the extension 12, the rotating motion of the core 16 is transmitted further to the sliding gear 4 and therefrom to the;'counter-gear 27 and through the

other gears

28 and 30 to the set of cams 32 controlling the heald shafts (not shown).

The drive by the rack 22 is oriented so as to cause a direction of rotation of the set ofcams 32 opposite to direction in which they rotate during normal weaving. The location and distance betweenend stops 34 and 35 must be adjusted so that the piston 24 causes a return movement of the heald shafts corresponding to one turn or cycle of the weaving loom. After the described return turning of the set of cams 32, the recently woven-in weft thread can be removed from the fabric.

The release of the above-described push button or pedal (not shown) enables thethree-way valve to release the pressure air from the air cylinder 25 by the action of the return spring 26 on the'piston rod 23 and thus a return of the rack 22 toward its original left hard terminal position until the stop dog 33 strikes the second end stop 34. The return movement of the rack 22 is transmitted solely to the rim 20, the turning of which causes a return of the rollers 19 into the system of recesses 18 in the core 16 of the free-wheel coupling 17, thus releasing the free-wheel coupling 17.

The mechanism is thus prepared for a repeated operation; after a new pressing of the push-button or pedal, another weft thread can be removed.

After the removal of the required number of weft threads had been accomplished, the attendant sets the two arm lever 8 into its original dash line position, that is into position ll according to FIG. 2, whereby the extension 12 is removed from engagement with the recess 15 of the core 16 of the freewheel coupling 17, and the second extension 11 enters the recess 13 of the collar 14 of the shaft 2. The mechanism is thus again in condition to transmit the torque from the drive of the weaving loom to the heald shafts.

The invention can be applied as part of a weaving loom if an easy removal of faulty weft threads is required. The mechanism of the invention is particularly useful in jet weaving looms, wherein the weft threads are inserted into the fabric in measured separate lengths.

Although the invention is illustrated and described with reference to one preferred embodiment thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a preferred embodiment, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

' l. A mechanism for driving the heald shafts of a weaving loom in the rearward direction, which is the reverse of their weaving direction, in order to permit the removal of woven in weft-threads, the loom having heald shafts and means for driving the heald shafts in the forward weaving direction comprising a drive shaft rotatably supported on the frame of the weaving loom, said drive shaft freely slidably and rotatably supporting a slidable gear and the means for driving the heald shafts, an over-running clutch having a driving and a driver part, and means for selectively connecting and disconnecting such driving and driver parts, second and third clutches for alternately coupling the gear with its supporting drive shaft and with the driving part of the over-running clutch, and means for selectively driving the driving part of the over running clutch in cycles in each of which the cam by which the heald shafts are turned is rotated in said rearward direction through an angle equalling the degree of turning of the cam of the heald shafts in the opposite direction in one cycle of the weaving operation of the loom.

2. A mechanims according to claim 1 wherein the means for driving the driving part of the over-running clutch comprises a rack gear, a pressure fluid receiving cylinder having a piston with a piston rod, the piston rod being connected to the rack gear, and comprising a stop dog on the piston rod and spaced end stops for the dog on the frame of the weaving loom, said, rack gear meshing with a further gear, said further gear being affixed to the driving part of the over-running clutch.

3. A mechanism according to claim 1, wherein said second and third clutches are toothed clutches each having one part thereof disposed on a respective one of the opposite sides of the slidable gear, the other part of each second and third clutch being a part which matingly engages a respective formation on the supporting shaft and drive part of the over-running clutch.

Claims

1. A mechanism for driving the heald shafts of a weaving loom in the rearward direction, which is the reverse of their weaving direction, in order to permit the removal of woven in weftthreads, the loom having heald shafts and means for driving the heald shafts in the forward weaving direction comprising a drive shaft rotatably supported on the frame of the weaving loom, said drive shaft freely slidably and rotatably supporting a slidable gear and the means for driving the heald shafts, an over-running clutch having a driving and a driver part, and means for selectively connecting and disconnecting such driving and driver parts, second and third clutches for alternately coupling the gear with its supporting drive shaft and with the driving part of the over-running clutch, and means for selectively driving the driving part of the over running clutch in cycles in each of which the cam by which the heald shafts are turned is rotated in said rearward direction through an angle equalling the degree of turning of the cam of the heald shafts in the opposite direction in one cycle of the weaving operation of the loom.