US3720237A - Arrangement for holding weft threads - Google Patents

Abstract

AN ARRANGEMENT TO BE USED IN A LOOM FOR HOLDING THE WEFT THREADS THAT EXTEND BETWEEN AN EDGE OF THE FABRIC AND SHUTTLES CONTAINED IN A DROP BOX OF THE LOOM, WHEREIN FIRST AND SECOND RETAINING MEMBERS ARE POSITIONED ON ONE SIDE OF THE SLEY BETWEEN THE DROP BOX AND THE EDGE OF THE FABRIC WITH THE RETAINING MEMBERS EXTENDED TRANSVERSELY OF THE WEFT THREADS AND PROVIDED WITH A RIBBED PROFILE SO THAT A STREAM OF AIR CAN BE DIRECTED TOWARDS THE WEFT THREADS FROM A BLOWER NOZZLE POSITIONED ON THE OTHER SIDE OF THE SLEY, SO AS CONTINUOUSLY TO FORCE THE WEFT THREADS AGAINST THE RETAINING MEMBERS AND TENSION THEM WHEREBY THE THREADS ARE HELD APART IN AN ORDERLY MANNER.

D R A W I N G

Description

March 13, 1973 R. KELDANY 3,720,237

ARRANGEMENT FOR HOLDING WEFT THREADS Filed June 10, 1971 2 Sheets-Sheet 1 March 13, 1973 K N 3,720,237

ARRANGEMENT FOR HOLDING WEFT THREADS Filed June 10, 1971 2 Sheets-Sheet 2 FIG 2 I 1 3O 31 I United States Patent 9 3,720,237 ARRANGEMENT FOR HOLDING WEFT THREADS Rachid Keldany, Egg, Zurich, Switzerland, assignor to Ruti Machinery Works Ltd., formerly Caspar Houegger, Zurich, Switzerland Filed June 10, 1971, Ser. No. 151,855 Claims priority, applicafitgriss/wigzerland, June 19, 1970,

9 Int. Cl. D03d 43/10 US. Cl. 139-170.3 7 Claims ABSTRACT OF THE DISCLOSURE threads from a blower nozzle positioned on the other side of the sley, so as continuously to force the weft threads against the retaining members and tension them whereby the threads are held apart in an orderly manner.

The present invention relates to an arrangement for holding apart weft threads extending from the edge of the fabric to the shuttles located in the drop box, and is for use on a loom having a drop box accommodating a plurality of shuttle boxes.

When weaving with different types of yarn which are inserted by dilferent shuttles, use is made of a drop box which comprises a separate compartment for each shuttle. The drop box is movable and can be so actuated that, for each weft thread insertion movement, it brings the shuttle with the required type of yarn into the starting position in relation to the sley, for throwing the shuttle or inserting the pick. The weft threads on the bobbins of the shuttles remain always connected to the fabric. Thus, weft threads continuously run from the bobbins contained in the drop box to the edge of the fabric adjacent the drop box. As a consequence of the movement of the drop box and of the sley, these portions of weft thread running from the shuttles to the edge of the fabric are not always tensioned but are slack. There thus arises the danger of their becoming tangled with each other so that when a weft thread of a given type of yarn is being inserted, the weft thread of a second type of yarn may be entrained and pulled into the shed with the required type of yarn. This results in strangers as they are called, which are undesired defects in the weave.

To remedy this troublesome situation, it is known to hold the portions of weft thread briefly by mechanical means at a point between the drop box and the edge of the fabric. It is also known to hold the portions of weft thread by means of suction nozzles. However, a suction method, for example, has the disadvantage that the zone affected by suction is relatively small, i.e. the suction action is effective only over a relatively small extent of the thread. Moreover, all these systems have the disadvantage that they do not work satisfactorily for all types of yarn, i.e. unrequited threads are always drawn into the sheds again which results in the undesirable defects despite the use of these known arrangements.

According to the present invention, this disadvantage is avoided by providing on one side of the sley a first weft thread retaining member or means which moves with the sley and is located between the drop box and the edge of the fabric, and a fixed second weft thread retaining memice her or means spaced from the first. These retaining members are positioned so that'they extend transversely of the weft threads and are provided with a ribbed profile on that of their sides presented to the sley, and fitted or positioned on the other side of the sley is a blower nozzle which produces a stream of air directed towards the weft threads so as to force the weft threads against the retaining members and tension them so the threads are held apart in an orderly manner.

The invention will now be described in more detail by reference to the following embodiment, reference being had to the drawings, and in which:

FIG. 1 shows a perspective view of one embodiment of an arrangement according to this invention as seen from the front; and

FIG. 2 is a schematic plan view of a portion of the arrangement of FIG. 1 showing different stages in the weaving operation.

In the two figures, like parts are designated by like reference numerals.

Referring further to the drawings, the drop box 11 has four shuttle compartments or boxes 12, one for each of the shuttles 13, 14, 15, and 16. Each of the shuttles 13 to 16 is provided with a bobbin for carrying a given type of weft thread yarn. The drop box 11 is moved up and down by actuating means (not shown) in such manner that the shuttle with the required type of yarn is brought to the level of the sley 17, in which position the shuttle thus selected is ready to insert a weft thread. A reed 18 with teeth 19 is secured to the sley 17. Warp threads 20 can be seen to run between the teeth 19 of the reed, and the woven fabric 22 emerges below the temple 21 (see FIG. 1).

The beat-up zone 36 (FIG. 2.) of the fabric being woven and the portion of the edge 38 of the fabric immediately adjacent thereto are covered by the temple 21 in FIG. 1. The weft threads or weft thread portions 23, 24, 25, and 26, respectively extend from this edge portion 38 to the shuttles 13, 14, 15, and 16. Mounted on the rear side of the sley 17 and movable therewith. is an air discharge or blower nozzle 27 which produces a forwardly directed stream of air when an air blower device, not shown, that is operatively connected to the nozzle is in operation. The nozzle 27 has a flat or elongate form of outlet orifice for directing the discharge of air supplied to it by the blower device, the longitudinal edges 28 of this orifice or opening extending transversely of the weft threads 23 to 26. The nozzle 27 has its narrow sides widening towards the outlet orifice, whereas its broad sides, which terminate at the edges 28, run parallel with each other.

As best seen in FIG. 1 a first and a second weft thread retaining member or means 30 and 31 respectively are provided at the forward or front side of the sley for maintaining the weft threads spaced apart. The retaining member 30 is mounted on the sley 17 and reciprocates with it during the weaving of the fabric. Furthermore, this member 30 is mounted so as to execute up and down movements in rhythm with and in the same direction as the movement of the drop box 11. The mechanism required for producing these movements is comprised exclusively of known elements and is therefore not described in any detail here.

The first retaining member 30 consists of small round discs 32 arranged side-by-side but with a gap or recess present between each two adjacent discs 32 so as to form a series of rib-like weft thread retaining means. These gaps can be formed by distance pieces inserted between the discs 32 and consisting for example of discs of smaller diameter than that of the discs 32 so as to space discs 32 apart an amount suflicient to allow a length of weft thread to be freely received in the gaps between discs 32. The discs 32 and the distance pieces are arranged in a line along an axial shaft and are held firmly in position by means of a screwbolt 33. The retaining member 31 is fixed in position in that it is secured to a fixed part of the loom and does not execute any movements. Member 31 is of broadfaced construction and has a ribbed or comb-like configuration which comprises teeth 34 directed towards the sley 17 and which provide means by which the weft threads can be maintained spaced apart when they are guided between the teeth.

When the loom is operating, the drop box 11 is moved up and down, by mechanism not shown, so that that of the shuttles 13 and 16 carrying the thread which is required to be inserted is moved to the level of the sley 17 and on the latter is thrown through the shed and back again into its associated shuttle box 12. If it is assumed that the shuttle 16 has just entered its shuttle box 12 again from the right, the weft thread 26 inserted by it into the shed runs at this moment over a straight line from the shed to the shuttle 16 as can be seen from FIG. 1 and FIG. 2a. Thereupon, the sley 17, and with it the reed, swing towards the beat-up zone 36 and beat up the weft thread 26. At the same time, the shed is changed so that the thread 26 is woven into the fabric.

If it is assumed that the drop box 11 then descends and brings the shuttle 13, for example, to the level of the track of the sley 17, then the distance from the edge 38 of the fabric to the shuttle 16 increases. The thread 26 is firmly held in the fabric 22, so that a portion of weft thread, corresponding to the greater distance, must be withdrawn from the bobbin in the shuttle 16. Furthermore, the sley 17 executes its movement in such a manner that the distance between the shutter 16 and the edge of the fabric 38 is further increased. The position after throwing the shuttle 13 is shown in FIG. 2d. If, after the weftthread insertion movement executed by the shuttle 13, the shuttle 15 for example is then to execute a weft thread insertion movement, the drop box 11 must be raised again to an appropriate extent. The distance between the shuttle 16 and the edge 38 of the fabric thus becomes smaller again. Further diminution of this distance is also caused by the approach of the sley 17 to the beatup point or zone 36. The portion 26 of the thread present between the shuttle 16 and the edge 38 thus becomes slack. The same applies as regards the other portions 23, 24 and 25 of weft thread. Because of the movements of the sley 17 and of the drop box 11, the portions of thread 23 to 26 slacken to varying extents.

The purpose of the air discharge or blower nozzle 27 and of the retaining members 30 and 31 is to prevent these slack lengths of thread 23 to 26 from becoming entangled with each other. The movements with the arrangement occurring in connection with the elements 27, 30 and 31 are illustrated in FIG. 2. During the above-described entry movement of the shuttle 16, the portions of thread 23, 24 and 25 were slackened to varying extents and the thread portion 26 was tensioned (-FIG. 2a). The portions 23, 24 and 25 when slackened are continuously prevented from sagging by the stream of air emerging from the nozzle 27. At different vertical positions along the height of the retaining members 30 and 31, these portions are blown or deposited between the discs 32 and the teeth 34, and move up and down with the movement of the drop box 11 and of the retaining member 30. Loops 35 are thus formed by means of the stream of air, so that the thread portions 23, 24 and 25 are always held taut to some extent. The formation of the loops 35 thus offsets the extra length of the thread- portions 23, 24 and 25. (See, for example, FIGS. 2a and 2b.)

It can be seen from FIG. 2b that the portions of weft thread 23, 24 and 25 have passed out of the retaining member 30 at the moment when beat-up takes place, but are held in position spaced apart in the vertical direction by the member 31. When the sley 17 now moves back, the retaining member 30 moves with it. The still taut threadportion 26 also moves between two of the discs 32 of the retaining member 30 corresponding to its position in the vertical direction. Its position in the vertical direction is thus fixed. The other thread- portions 23, 24 and 25 are also caused to pass between discs 32 of the retaining member 30, in the manner described above, before they have left the teeth 34 of the retaining member 31. As a result of the loops 35 the weft thread portions between the edge 38 of the fabric and the shuttles in the box 11 are relatively firmly tensioned when moving into the gaps in the retaining member 30. Thus, the thread portions 23 to 26 are engaged in this retaining member 30 under conditions in which they are in a stretched or tautened and orderly state. The situation just described is illustrated in FIG. 20.

When the sley 17 is at its greatest distance from the beat-up zone 36, the situation illustrated in FIG. 2d exists. Here, it is assumed that the shuttle 13 is at the right during its insertion movement. At this stage of operations, the thread portions 24, 25 and 26 have moved from the recesses between the teeth 34 of the retaining member 31. They are in a relatively taut condition, since the distance of the shuttles 14, 15 and 16 from the edge 38 of the fabric is relatively large and, moreover, the stream of air from the nozzle 27 tensions the thread- portions 24, 25 and 26. Upon renewed forward movement of the sley 17, the thread portions 24, 25 and 26 again move between the teeth 34 of the retaining member 31. Their positions between the shuttles 14, 15 and 16 and the edge 38 of the fabric corresponds to the situation illustrated in FIG. 2a. After the shuttle 13 has again returned to its compartment 12 in the drop box 11 and the latter has again moved vertically, the thread-portion 26 is relatively more slack. It is, however, held by the retaining members 30 and 31 and i prevented from becoming involved with the other thread portions.

The arrangement described prevents the occurrence of the strangers as they are called (as above mentioned). The thread portions 23 to 26 are kept held apart in a much more reliable manner than with the known threadholding means. The portions 23 to 26 of weft thread do not remain at the same points or locations on the retaining members 30 and 31 during operation of the loom, but change their positions on these members as the drop box 11 moves. Furthermore, the two retaining elements alternately perform the weft thread holding or retaining action. It is very possible that these features contribute considerably to the advantageous mode of operation. A further advantage obtained is that the thread portions 23 to 26 are continuously held clear of the path taken by the shuttles 13 to 16, i.e. of the zone located above the sley 17. When a shuttle, e.g. the shuttle 16, enters the shed, it is of importance to the quality of the fabric produced that the thread portion 26 should form a uniform loop behind the shuttle 16. Thus, tangling of the weft threads is avoided in the immediate vicinity of the edge 38 where, of necessity, the weft threads come very close to each other. Since, when passing in front of the nozzle 27, the shuttle 16, for example, intercepts or checks the stream of air emanating from the nozzle, the above-mentioned loop of thread is located behind and in the lee of the shuttle '16. The stream of air does not interfere with the loop and it has been observed that when this stream of air has any effect at all this effect can only be of advantage.

The invention is not limited to the embodiment illustrated and described. As can be seen from FIG. 2, the stream of air from the nozzle 27 is directed towards the spaced located between the edge of the fabric 38 and the retaining member 31 adjacent thereto and above the sley 17. Instead of this, the stream of air can however also be directed towards the space located between the retaining members 30 and 31.

Also, both retaining eselements can be of the same constructional configuration or design as the member 30 or the member 31. It is advantageous if the retaining members are fitted at such positions that they divide the distance between the right-hand end of the drop box 11 and the edge 38 of the web into three zones of approximately equal length. This embodiment can, however, also be modified by the provision of more than two retaining members spaced apart between the drop box 11 and the edge 38 of the fabric.

The widening or divergence of the narrow sides of the blower nozzle 27 towards the outlet orifice provides the advantage that the thread portions 23 to 26 are separated, i.e. blown apart, if the stream of air is distributed at least roughly symmetrically over the height of the outlet orifice in relation to the thread portions 23 to 26.

To adapt the arrangement for use with weft threads formed of yarns of differing conditions, e.g. finer and courser yarns, it is desirable to be able to vary or regulate the intensity of the stream of air supplied through the nozzle 27, which can be accomplished by conventional regulator means.

In the case of a not fully utilized, i.e. a relatively narrow width of fabric, the fabric does not run to the lateral end of the reed 18 shown in FIG. 1. In this case, the nozzle 27 can be fitted in such manner that the stream of air is blown between the teeth 19 of the reed to produce the tautening of the weft thread portions 23 to 26.

What is claimed is:

1. In an arrangement for holding weft threads extending in a loom from the edge of the fabric being woven to the shuttles contained in compartments in the drop box of the loom, the combination with said arrangement which provides: a movable first retaining means vertically arranged on one side of the sley between the drop box and the edge of the fabric and operatively connected to the sley and movable therewith, said first retaining means provided with a ribbed profile for receiving and holding the weft threads spaced apart; a second retaining means vertically arranged in fixed position and at said one side of the sley for receiving and holding the weft threads spaced apart, said second retaining means provided with a ribbed profile and positioned between said movable first retaining means and the edge of said fabric; each of said rfirst and second retaining means extending transversely of the weft threads and having its profile for receiving and holding the weft threads spaced apart presented to the sley; a blower nozzle operatively mounted on the sley and positioned between one of said retaining means and the edge of the fabric being woven for directing a stream of air towards said weft threads to force them into engagement with said ribbed profiles, said nozzle being positioned generally opposite said retaining means on the other side of the sley therefrom; and each of said ribbed profiles of said first and second retaining means providing a generally vertically arranged series of fixed recesses for receiving therein the weft threads blown by the air stream from said blower, the said recesses being freely open towards the sley whereby said weft threads are enabled to be periodically moved into and out of said recesses in each of said retaining means so as alternately to be held by one of the said retaining means while being free of the other when the loom is in operation.

2. The arrangement of claim 1 in which one of said retaining means is positioned adjacent an edge of said fabric and the stream of air is directed towards the space above the sley which is located between the said edge of the fabric and the said retaining means adjacent said edge.

3. The arrangement of claim 1 in which the outlet opening of the said blower nozzle is of elongate form and the long sides of the said opening are positioned transversely of the weft threads extending between the drop box and the edge of the fabric.

4. The arrangement of claim 3 in which the narrow sides of the said blower nozzle widen towards the outlet orifice of the nozzle, for producing an air stream formed by the nozzle which is distributed at least approximately symmetrically with the weft threads in a direction transverse of said threads.

5. The arrangement of claim 1 in which at least one of said retaining means is comprised of discs arranged in a row and spaced apart to provide one of said recesses between each neighboring two of said discs.

6. The arrangement of claim 1 in which at least one of said retaining means has a comb-like zone, the teeth of which are arranged to extend in a direction towards a side of the sley.

7. The arrangement of claim 1 in which one of said retaining means is positioned adjacent the drop box of the loom and moves in rhythm with and in the same directions as the movements of the drop box.

References Cited UNITED STATES PATENTS 3,507,307 4/1970 Picanol 139l70.3 2,919,723 1/1960 Brandon 139-1703 FOREIGN PATENTS 811,897 4/1959 Great Britain 139170.3 1,440,956 4/1966 France 139'-170.3 436,157 11/1967 Switzerland 139-1706 HENRY S. JAUDON, Primary Examiner

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