US3533451A - Tread clamping device for weaving machines - Google Patents

Description

United States Patent Inventor Johann Sting],

' l0 Bottgerstrasse, Hohenberg/an der Eger,

Germany App1.N0. 765,440 Filed Oct. 7, 1968 Patented Oct. 13, 1970 A ignee George Fischer Ltd. Brugg,

Brugg, Switzerland Priority Oct. 6, 1967 Switzerland 14033/67 TREAD CLAMPING DEVICE FOR WEAVING v 50 Field ofSearch 242/147 149:139/116,122l27P References'Cited Primary Examiner-Henry S. .Iaudon Alt0rney-Rodney C. Southworth ABSTRACT: The present invention relates to a thread clamping device for weft thread or threads for use in a weaving machine with weft thread supply cones located outside the shed which weft threads are inserted into the shed of a fabric being woven by carriers or other means for the purpose.

MACHINES 8 Claims, 7 Drawing Figs.

U.S.Cl 139/122, 139/127 Int. Cl D03d 47/18 1:1" mm '7 8 I" 17 5; J 18 Patented Oct. 13, 1970 3,533,451

Sheet 1 of 3 INVE TOR. Johann Shngl BY ha a? Patented Oct. 13, 1970 Sheet 2 of 5 INVEIQTOR. Johann Sfingl Patented Oct. 13, 1970 3,533,451

Sheet 3 of 3 'INVENTOR.

Johann Sh'ngl 1 TREAD CLAMPING DEVICE FOR WEAVING MACHINES BACKGROUND OF THE INVENTION In a weft insertion principle according to which the weft thread last inserted in the fabric extends temporarily via a thread control member and a primary brake mechanism, to the weft supply cone, that weft is supplied to a right-hand weft insertion member by means of a depresser or pull-down member, the said insertion member then passing the weft to the center of the fabric as a loop where it transfers it as a measured pick to a left-hand insertion member. The weft is then cut at the selvage where reversed. This principle requires, after transfer of the thread, actuation of a device which clamps the thread coming from the supply cone so that no thread can be obtained thence and that the cut weft end can be extended by the left-hand insertion member.

In color or other work in which a plurality of feeders with accordingly numerous threads and supply points, there arises the problem of locating a like number of thread clamping devices on the machine frame so as to save the maximum of space, or to arrange it in the space available. With known devices clamps for an eight-color loom, for example, take an inordinate space. It is an object of the present invention to provide a thread clamping device which is simple in construction and operation and does not require high precision manufacture to provide a maximum of operational reliability and which also occupies a minimum of space.

SUMMARY OF THE INVENTION The thread clamping means according to this invention is characterized in that for each thread it comprises two leaf springs that face each other and are movable to and from an open position into a clamping position and which have overlapping portions of considerable area. Weft thread guides restrain the wefts to run through the clamps only at the overlapping areas. These leaf springs are fixed in support means, one of which is movable relatively to the other so that the overlapping portions engage in the clamping position so as to provide a clamping action and lock the thread against movement, but when opened, free it to impose no drag on it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagrammatic view of the weft insertion principle, also showing the clamp as shown in plan;

FIG. 2 is a sectional view of an open thread clamping device according to this invention;

FIG. 3 is a similar view of the clamping device according to this invention in closed position;

FIG. 4 is an elevation of a thread clamping device according to this invention designed for eight weft threads in different colors;

FIG. 5 is a section of the thread clamping device according to FIG. 4 and taken at line A-A;

FIG. 6 is a view of a thread clamping device according to a modification of the invention with adjustable clamping leaves for four weft threads; and

FIG. 7 is a section of the thread clamping device according to FIG. 6, taken at line 8-3.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a diagrammatic view of a principle of weft insertion to which the invention may well be applied. The fabric .1 havinga right-hand selvage 2 which may preferably be a false selvage, is being woven in a loom with a slay 3, slay support 4 and a reed 5. Indicated generally is a driving unit 6 with a guide 7 for the weft insertion member 8. Located between the slay 3 and the guide 7 is a thread pull-down member 9 which supplies the weft thread to a carrier 11 fixed at the end of a weft insertion rapier or member 8 and feeders 12 which selectively supply the weft thread coming from the cones 13 to cone covers 14 is the thread clamping device 16. The cohstruction and operation of the basic loom parts here are shown in US. Pat. No. 2,641,285. From a weft thread 17 last iiiserted, the thread 10 passes via a loop 18 to the carrier lI,

that feeder 12 which is in feeding position, and finally, extends back to the supply cone 13. After the weft 10 has been trari'sfered by the right-hand insertion member 8 to the left-hand ihsertion member 19, the said thread is cut by a thread cutting attachment 20 at the loop 18 and preferably between the maih body of the warp and the warp at the false selvage 2. This lefthand carrier 19 extends the cut end to complete the pick in a known manner. Driving means (not shown) force mobile clamping springs 21 against stationary clamping springs 22 of the thread clamping device 16 at this time, the weft thread ll) located between being held fast so no weft is drawn from the cone after enough for a pick has been measured.

FIG. 2 is a view of an open thread clamping device whibh basically comprises a stationary clamping spring 22 and a mobile clamping spring 21 and which does not necessarily requll'e parallel relationship between the clamping springs 21, 22 owing to its manner ofoperation.

FIG. 3 is a view of a closed thread clamping device in which, thanks to the resiliency of the clamping springs 21, 22 an accurate fit of the overlapping portion 23 is possible even after the rest position according to FIG. 3 is reached. This clampitig principle enables weft threads of different counts to be clamped without any particular adjustments or preparations:

bracket being, in effect, an integral part of the plate. Attached to the base plate 24 by means of screws 27 is a segment or rlin 28 in which the clamping springs 22 are inserted, preferably by being soldered into slots in the rim. The hub supports a shaft 30 fixed by a set screw 29 on which a mobile segment hub 32 is oscillatable on needle bearings 31. It is secured against axial displacement by means of washer 33 and screw 34.

Further clamping springs 22 arerecessed in projections or sectors fixed to and projecting from hub 32. Mounted on a tenon 36 rigidly connected to the projection or sector is a ball or other bearing 37 which laterally abuts against a spacer 38 and a washer 41 attached by means of a screw having a grooved head. Guided in a bracket or holding portion 26 by guides 42 is a positioning member or plunger 43 which is moved by control units e.g. cam means (not shown) and acts. against the action of a tension spring 45 hooked into the groove 39 and about a bolt 44, on the ball bearing 37. The segment moved by this plunger and spring in the directions indicated by arrow 46 and the clamping springs 21, 22 are displaced against or away from one another. Motion is limited to only a few degrees of oscillation.

' A flat annular, segmental bar 47 is attached to the base plate 24 by means of screws 48, one at either end, and is provided with a number of eyelets 49 identical with the number of pairs of clamping springs, the weft thread 10 being passed through them between the clamping springs 21, 22 and then drawn away through eyelets 50 in the base plate'24.

FIG. 6 is a viewof a modification of the invention with a thread clamping device with adjustable clamping springs for four weft threads, and FIG. 7 is a section of the same clamping means, the same clamping spring principle being applied, in this embodiment as well except that motion is rectilinear. A slide guide 51 is provided with thread guide eyelets and bores 53, the later rotatably supporting bolts or pins 55 held axially by means of securing rings 54. Attached to the bolts are holders 56 with soldered-in clamping springs 57 and fixing pins 58.

The slide guide 51 is provided with adjusting screws 59 which actupon a right-hand and left-hand leg 60 of the holder 56 so that the clamping springs can be individually swivelled.

Normally these leaf springs are adjusted to position close to the running weft and then retained in that set position. The slide guide 51 holds the slide 61 actuated in the direction of arrow 62 by driving means (not shown), e.g. by cams. It is provided with soldered-in clamping springs 63 and secured by plates 64. Slide 61 has an easy rectilinear motion in its slide channel and is moved to bring springs 68 into pressure engagement with springs 57 with the weft between when that weft is to be locked against withdrawal. A member 66 equipped with eyelets 65 is firmly bolted to the slide guide 51. The thread 67 passes through the eyelets 52, 65 andbetween the clamping springs 57, 63, and it may pass a variety of different counts in the embodiment of the clamping unit 68. In other words, the count, type or character of the weft makes little difference.

While examples of four and eight color units are given, the device may be adapted to a single weft or to any reasonable plurality. It is to be noted that for multiweft work one simple motion opens all clamps and closes all. With the system herein involved wefts not being drawn are released along with the one that is, however, this only permits the inactive wefts to be extended slightly as the fabric to the selvage of which they are connected moves away. Actually, only the running weft is affected in normal patterns. Only the feeders 12 for two wefts are shown here, but there an equal number of these for the number of wefts in action. Pattern control governs the presentation of weft as desired.

This disclosure of a preferred embodiment of the invention is to be interpreted as illustrative of forms the invention may take and modifications will readily occur to those skilled in the art. The invention is not to be restricted except by the scope of the appended claims wherein the novel features desired to be protected by Letters Patent are set forth:

I claim:

1. A thread clamping device for weaving machines of the type in which weft is drawn from a supply positioned outside a shed of a fabric being woven and is inserted as a pick of weft by means moved into and from the shed, characterized in that, the clamping device includes two relatively movable support means, cooperating leaf springs having overlapping ends functioning as a pair, one of which is fixed in each of said support means, guide means for the weft positioned to guide it between the overlapping portions of said leaf springs, and means to move said support means to separate said leaf springs and to press them together as the weft is to be released or locked against withdrawal from the supply.

2. A thread clamping device as claimed in claim 1, wherein a plurality of pairs of leaf springs are fixed in said support means and a like number of guide means for the weft are provided.

3. A thread clamping device as claimed in claim 2, wherein the guide means are mounted in the support means.

4. A thread clamping device as claimed in claim 2, wherein the support means comprise sector-shaped members, hubs from which said members extend, one of said hubs and its sector-shaped member being fixed and the other of which is movable.

5. Mechanism as defined in claim 2, wherein the movable support means is moved in a relatively small angular oscillation to open and to close the said leaf springs.

6. Mechanism as defined in claim 2, wherein means for moving said movable support means includes a plunger pressing against a part of the support means and a spring for returning the parts to the opposite position.

7. Mechanism as defined in claim 2, wherein leaf springs in one said support are fixed therein, and means for adjusting the leaf springs in the other support which includes swivelable holders, one for each spring, and threaded means to adjust and retain said holders in a fixed position to which they have been adjusted.

8. Mechanism as defined in claim 2, wherein said support means are guided and moved in a rectilinear pathway.

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