US3434507A - Weaving shuttle - Google Patents

Description

March 25, 1969 A. FREIHOFER wmvms SHUTTLE Sheet ot2 Filed Nov. 17, 1966 March 25, 1969 A. FREIHOFER WEAVING SHUTTLE Sheet Filed Nov. 17. 1966 x Fig.3

Fig.6 E

3,434,507 WEAVING SHUTTLE Alexis Freihofer, Tann-Ruti, Zurich, Switzerland, assignor to Ruti Machinery Works Ltd., formerly Casper Honegger, Switzerland, Ruti, Zurich, Switzerland Filed Nov. 17, 1966, Ser. No. 595,128 Claims priority, application Switzerland, Dec. 23, 1965, 17,740/65 Int. Cl. D03d 47/14 US. Cl. 139-125 12 Claims ABSTRACT OF THE DISCLGSURE A shuttle for a weaving loom having a retaining arrangement which holds a weft yarn with a predetermined force for picking the yarn into the shed of the loom and from which the yarn can be drawn out after the pick has been completed. The retaining arrangement comprises at least two separate retaining means which provide different degrees of retaining force for holding the yarn and which are independently adjustable so that the retaining force provided by each can be individually varied to reliably retain the yarn during movement through the loom and to allow the yarn to be drawn out of the shuttle by a braking force without excessive springing back of the yarn.

The present invention relates to a shuttle for a weaving loom and in particular to a weft yarn picking shuttle having a retaining arrangement in which weft yarns are retained with a predetermined force to introduce them into the shed, and from which the weft yarns can be withdrawn after the pick has been completed.

A weaving shuttle is already known which has two clips for retaining the weft yarn and for introducing the yarn into the shed from one direction and then from the other. During this procedure, the yarn is drawn off directly from a large supply bobbin disposed externally of the loom. The shuttle has a clip at each end, one clip serving for picking in the one direction and the other for picking in the other direction. Each clip has a fixed part against which a plate rotatable about a pivot is pressed. The yarn is jammed between the fixed part and the plate.

Furthermore, a shuttle is also known which contains a yarn retaining arrangement having a braking element consisting of a multiplicity of bristles impinging and bearing against a plane.

When a shuttle of the type described or another picking member such as, for example, a rod provided with a yarn retaining arrangement, is used in a weaving process in which the yarn is, after the pick has been completed, drawn out of the retaining arrangement, then the picking member is required on the one hand to retain the yarn reliably and securely and on the other hand sufliciently loose to ensure that at the instant at which the yarn leaves the retaining arrangement it will not (or will not to any great extent) spring back due to its elasticity. Excessively vigorous springing-back is detrimental to reliable grasping of the yarn in order to stretch it before being beaten up by the sley. Consequently, the quality of the resulting fabric is diminished. Firm retaining of the yarn by the shuttle to prevent slipping of the yarn is particularly important when the length of the yarn to be picked is determined by the fact that the shuttle carries the yarn with a free end of pre-determined length. During the picking step and, at a pre-determined position of the shuttle during movement along the shed, the yarn to be picked is stopped on the side of the large-supply bobbin and is thus drawn out of the retaining arrangement.

The known shuttles mentioned heretofore do not satisfactorily fulfill the above-mentioned requirements, i.e., they either retain the yarn so firmly that it cannot be ice drawn out of the travelling shuttle without springing back by an excessive amount, or they retain it so loosely that it slips in the retaining arrangement and accurate supplying of the required length is not possible.

Advantageously, these problems are avoided by the shuttle or picking member of the present invention. In general, the present invention is directed to a shuttle which will ensure uniformity in the introduction of yarn into the shed. This uniformity requires reliable retaining of the weft yarn in the shuttle and also a form of yarn withdrawal which is not or is only very slightly jerky at the instant the yarn is drawn out of the shuttle.

The present invention thus contemplates a shuttle or picking member having a retaining arrangement with at least two retaining means or zones of varying retaining force, the first zone exhibiting the greater degree of retaining force and, as seen in the direction of the yarn movement during the withdrawal of the yarn from the retaining arrangement, being located in front of the second zone, which exhibits the smaller degree of retaining force.

In a particularly advantageous process for transferring yarn to the shuttle, the yarn is laid as a loop through the shuttle and then the loop is drawn out. However, in order to achieve the advantages of this invention and particularly to provide uniform yarn insertion, in such a process, entanglement of the yarn as it is transferred to the yarnretaining arrangement must be avoided. In accordance with this invention this is achieved by a special construction of the shuttle which is so shaped that the two halves of the loop are kept separate from each other, during the process.

The invention will now be described in greater detail in the description of several embodiments and with reference to the accompanying drawings in which:

FIGURE 1 is a plan view of one embodiment of the shuttle or picking member of this invention;

FIGURE 2 shows an elevation of the shuttle shown in FIGURE 1, partly in sectional along line 11-11;

FIGURE 3 shows an elevation of another embodiment of the invention;

FIGURES 4 and 5 show plan views of two additional embodiments of the invention which operate in a similar manner; and

FIGURE 6 shows still another embodiment in elevation.

In the figures, the same reference numerals designate like parts.

The shuttle shown in plan view in FIGURE 1 is designated by the reference numeral 11. The shuttle 11 has an elongated body with apertures 12 and 13 at each end. These apertures, as shown in the drawings, extend completely through the shuttle in the horizontal direction. Towards the center of the shuttle, each aperture narrows to form a slot 14 or '15, respectively. Each of the slots leads to a retaining arrangement, one of which comprises a first braking plate 16 that presses against a cover plate 17 serving as an abutment and that together with the plate v16 constitutes a first retaining means or zone, and a second similar braking plate 18 that also presses against the cover plate 17, again acting as an abutment. In this manner, the plate 18 and the cover plate 17 form a second retaining means or zone of the arrangement. The plate 18 is not shown in FIGURE 2 due to the selected position of the sectional view along which this figure is taken.

The cover plate 17 has not been shown in FIGURE 1 in order that the braking plates, 16, 18, 19 and 20 may be visible. Plate 17 should be considered as having been removed from the shuttle shown in FIGURE 1.

correspondingly, there is a second retaining arrangement at the other end of the shuttle. This arrangement comprises a braking plate 19 which is adapted to be pressed upwardly in a first retaining means or zone and also a second braking plate adapted to be pressed upwardly in a second retaining means or zone. Both plates also press against the cover plate 17 that acts as an abutment. In FIGURE 2, plate 19 is not shown. The plates or elements 16, 18, 19, 20 are of elongated shape and are rounded at their ends. They are, as can be seen from FIGURE 2, bevelled away from the plate 17 at the forward end as seen in the direction of picking.

The plate 16 is upwardly biased or pre-tensioned by means of the screw 21 and the spring 22, i.e., it is pressed against the cover plate 17 with a predetermined force. Similarly the plate 20 is biased against the cover plate 17 by means of the screw 23 and the spring 24. The screws 21 and 23 permit the adjustment of the pressure which the plates 16 and 20, respectively, exert against the cover plate 17. The biasing of the plates 18 and 19 is exactly the same as described for plates 16 and 20.

In order to achieve exact positioning of the yarn 25 under the braking plate 16 (i.e., between the braking plate and the cover plate), the guide or positioning pins 26 are provided. A yarn introduced between the plates 16, .17 is by this means retained exactly in the position determined by the pins 26, as shown in FIGURE 1. Appropriate pins or pegs 27 are also provided on both sides of the plate 19.

The hook secured on the loom is movably arranged, so that it is able to move from the position shown in FIGURE 1 through the aperture 12. During this movement, it engages yarn stretched on the other side of the shuttle 11 between the nozzle 34 and the yarn guide 28 and draws it, as a loop, through the aperture v12. At the same time, the two loop halves 25 and 25" are formed. The loop half 25 is up further than the loop half 25", i.e., it is raised higher than the other loop half as shown in FIGURE 2.

The free end 32 of the yarn 25 is retained by a suction nozzle 34. The yarn travels from the yarn guide 28 over a yarn clip or brake 31 secured to the loom to a yarn supply means located at the side of the loom and not shown.

During operation, before the propulsion of the shuttle 11 towards the left (as viewed in FIGURES 1 and 2) the hook '30 engages the yarn 25 supplied to it. by the yarn guide 28 and draws it through the aperture 12 in the shuttle 11. At this instant, the yarn clip 3.1 is still closed. The hook 30 then remains in the position shown in FIGURE 1. Subsequently, during the propulsion of the shuttle 11, the slot 14 (which is at the level of the loop half 25'), engages the loop half 25'. During the drawing out of the yarn 25 from the suction nozzle 34, the loop half 25' passes into abutment with the two pins 26 and the loop half 25" into abutment with the curvature located under the projection 33. Since, at that instant, the yarn clip 31 has trapped the yarn 25, the yarn, which has a free end 32, is drawn out over the hook 30. After the shuttle .11 has moved towards the left through a predetermined distance, the clip 31 is opened and the yarn 25 is drawn through the shed while simultaneously being drawn-off from a large-supply bobbin. As this takes place, the position of the yarn in the shuttle is that designated by the reference numerals 25a and 32a in FIGURE 1.

Shortly before the shuttle (during its travel towards the left) leaves the shed at the left-hand end of its path, the clip 31 is closed again. Consequently, the yarn 25 is completely drawn out of the shuttle 11. The instant when the yarn is clamped by the clip is so selected that the free end 32 (32a) of the picked weft yarn projects out of the loom by a short, predetermined amount. The retaining means of the retaining arrangement formed by the plate 16 and plate 17 is therefore required to retain the yarn 25 firmly enough to ensure that the yarn, during introduction into the shed and particularly from that instant at which the brake 3.1 is opened, does not slip therein. On the other hand, the braking elfect of the retaining arrangement must not be so great that the yarn springs back a noticeable extent as it leaves the arrangement, i.e., the end of the yarn does not snap back toward the shed. The yarn end 32 leaving the shuttle must, as the instant it leaves the retaining arrangement formed by plates 16, 17, and 18, be taken over by a holding means formed, for example, by a suction nozzle. This holding means is required to hold the yarn introduced into the shed stretched before and while it is beaten up by the sley.

In order to prevent springing-back of the yarn, the pressure applied by plate 16 is made sufiiciently strong to ensure secure and reliable retaining of the yarn 25. As can be seen from FIGURES 1 and 2, the braking plate 18 is also arranged in the direction of the yarn movement taking place during the drawing-out of the yarh from the retaining arrangement. Plate 18 is biased against the cover plate 17 by a pressure which is smaller compared with the pressure of the plate 16. This smaller pressure is so selected that the pull on the yarn 25 as it slides out through the plate 18, produces at most a practically insignificant springing-back of the yarn 25.

In order to achieve uniformly in the supply of the desired length of the yarn 25, i.e., in order to exactly dimension the length of the yarn 25 picked into the shed, it is essential that the free yarn end 32a should always have the same length. Thus, it must never happen that the two yarn halves 25 and 25" become entangled with each other. In order to prevent such entanglement, a projection 33 is provided in the shuttle 11 on the underside of the slot 14. As shown in FIGURE 2, the projection extends into the aperture 12. With this construction, the lower loop half '25", during the propulsion of the shuttle, takes up its position in the curvature located under the projection 33. It will also be appreciated that care'must be taken to ensure that the free end 3211 of the arm 25a does not become entangled or jammed-in, during the travel of the shuttle, with any part of the reed or with any other part of the loom. In order to prevent this from happening, there is provided on the rear side of the shuttle (as viewed in FIGURE 2), at the level of the slot 14, a horizontal notch for receiving the free yarn end 32a during the travel of the shuttle. The length of the said notch is as long as or slightly longer than the yarn portion extending from the outer positioning pin 26 as far as the free end 32a.

Since the arrangement and mode of operation of the retaining arrangement formed by the plates 19 and 20 together with the plate 17 is the same as that of the retaining arrangement described in the foregoing text and operates accordingly during the travel of the shuttle 11 from the left towards the right, no further description thereof will be given.

Two materials have primarily been found to be advantageously used for the plates 16, 18, 19 and 20. One of these materials is wood and the other is a plastic material coated with a layer of chromium.

In the case of the embodiment illustrated in FIGURES 1 and 2, the cover plate consists of a plastic material and the plates 16 and 17 or 19 and 20 are made of wood. Under these circumstances, a compression force on plates 16 and 19 of 50 to grams and on plates 18 and 20 of 5 to 30 grams has been found to be advantageous.

In addition, the guiding of the plates 16, 18, 19 and 20 during their upward and downward movement is advantageously such that the surface of each of the plates, which is able to contact the cover plate 17, remains parallel to itself. However, a slight degree of deviation from a movement of this kind is also possible without involving any danger of unsatisfactory operation.

As heretofore noted, FIGURES 3 through 6 show further embodiments of a retaining arrangement suitable for purposes of this invention. Only one half of a shuttle 11 is shown in these figures. In the shuttle shown in FIG- URE 3 an aperture 13 is also provided for the drawing-in of a weft yarn. In place of a weaker, spring-biased plate 18 of the second retaining means or zone of the retaining arrangement, a carrier 40 having bristles 41 on its upper side is provided. The carrier 40 is, in this embodiment, not movable. Due to their elasticity, the bristles press against the cover plate 17. By selecting a suitable bristle material, the force by which the yarn is retained is brought to or adjusted to the desired degree in a yarn brake or retaining means of this type. In place of bristles, it is also possible to use a fur-like material, a plush-like material, or a like fibrous material.

In the embodiment shown in FIGURE 4, the retaining arrangement comprises three different retaining means or zones. Proper retaining of the weft yarn 25a is effected by means of the plate 42 and positioning of the yarn 25a on the plate is again achieved by means of the pins 26. As seen in the direction of movement of the yarn 25, during drawing from the retaining arrangement, there are additionally arranged plates 43 and 44 which form two further retaining means or zones. The pre-tensioning of these plates diminishes step-wise, in the arrangement illustrated, from the plate 42 to the plate 44. In this arrangement, plate 44 is adapted to be very weakly pretensioned so that the springing-back of the yarn is greatly diminished. The pre-tensioning of the plates may, as shown in FIGURE 2, also again be effected by means of springs exerting pressure from below.

The embodiment in FIGURE 5 shows a further modification of the embodiment shown in FIGURE 4. Ac cording to FIGURE 5, there are provided in the shuttle 11 a first retaining means or Zone having the plate 50 and the positioning pins 26, and also a multiplicity (in this case, four) of additional zones. The additional zones are for-med by the plates 52 to 55 which are biased or pre-tensioned from below, for example, by means of a spring, and which impinge against an abutment provided by a cover plate. Due to the provision of five different zones by plates 50, 52, 53, 54 and 55 a decrease in the braking force on the yarn can be achieved in extremely small stages, down to, practically, the value zero.

An example of an embodiment producing a decrease in the retaining or braking force of the yarn which does not take place step-wise but in a continuous manner is shown in FIGURE 6. In this case, there is again an aperture 13 formed in the shuttle 11. Similarly, the shuttle again has a cover plate 17 serving as an abutment. The retaining arrangement is formed by a U-shaped leaf spring 60 having legs of varying length. The leaf spring is secured fast with the shuttle 11 by means of its short leg and with the aid of a securing means 61. Simultaneously, the long leg bears against a cover plate 17. The application pressure of this device is decreased continuously in the direction towards its free end and can be so adjustcd that the force at the free end of the long leg is decreased to zero. In this manner, it will be appreciated that the long leg provides a plurality of retaining means or zones along its length. For the positioning of the yarn, positioning pins 62 may again be provided. The curvature of the U-shaped leaf spring separates the upper and the lower halves 25' or 25", respectively of a drawn-in yarn loop (as shown in the embodiment of FIGURE 1). In order the lower loop 25" may not become caught up in the securing means 61 of the leaf spring, yarn guiding pins 63 are advantageously provided.

While the novel features of the invention have been shown and described and are pointed out in the appended claims, it is to be understood that various omissions, substitutions and changes in construction and arrangement of the features shown and described may be made by those skilled in the art without departing fro-m the spirit and scope of the invention.

What is claimed is:

1. A shuttle for a weaving loom having an elongated body and a retaining arrangement which holds weft yarn with a predetermined force for picking said yarn into the shed of the loom and from which said yarn can be drawn out after the pick has been completed, said retaining arrangement comprising at least two separate retaining means which provide different degrees of retaining force for holding the yarn, the first retaining means providing the greater retaining force and being arranged in front of a second retaining means in the direction of yarn movement which occurs during drawing out of the yarn from said retaining arrangement and said second retaining means providing a smaller retaining force than that provided by said first retaining means, each of said retaining means being adjustable independently of the other to provide varying degrees of retaining force, and the retaining force provided by each being individually varied to reliably retain the yarn during movement through the loom and to allow said yarn to be completely drawn out of the shuttle by application of a braking force to said yarn without excessive springing back of the yarn.

2. The shuttle of claim 1 in which at least one of said retaining means comprises an abutment and a plate, said plate being pressed against said abutment by a resilient member and being adapted to move towards and away from said abutment, the force exerted by said resilient member being a'djusta-ble.

3. The shuttle of claim 1 in which said elongated body has an aperture extending perpendicular to its longitudinal axis and to the direction of movement of the shuttle in the loom for allowing introduction of said weft yarn thereto in the form of a loop and a slot extending from said aperture in the direction opposite to that of the weft picking direction and leading to said retaining arrangement for guiding the yarn thereto, said slot having one boundary face from which a projection extends into said aperture and said projection being arranged between the slot and the rear wall of the aperture whereby the two halves of the yarn loop are kept separate from each other during movement of said retaining arrangement.

'4. The shuttle of claim 1 in which the second retaining means comprises an abutment and a fibrous material impinging against said abutment.

5. The shuttle of claim 1 in which the retaining force of each of said retaining means is so selected that the first retaining means provides sufiicient force to reliably hold said yarn and the other retaining means are arranged sequentially in the direction of the yarn movement during the drawing-out of the yarn from the retaining arrangement, the retaining forces of each of said other retaining means decreasing in relatively small stages down to a relatively very small value.

6. The shuttle of claim 1 in which said elongated body has a rear wall which slides along the sley during the picking movement, said rear wall having a notch formed therein at the level of the retaining arrangement for receiving the free end portion of the weft yarn to be picked, and said notch being at least sufiiciently long to insure that substantially the entire free end portion of the yarn is received thereby.

7. The shuttle of claim 1 in which said retaining arrangement includes a pair of yarn positioning elements, said element being operatively associated with said first retaining means to locate the weft yarn at a predetermined position.

8. The shuttle of claim 2 in which each of said retaining means has a plate which is pressed against an abutment by a resilient member, the plate of the first retaining means being pressed by a force of from 50 to grams and the plate of the second retaining means being pressed against the abutment by a force of from 5 to 30 grams.

9. The shuttle of claim 2 in which the plates and the abutment are made of chromium-plated plastic material.

10. The shuttle of claim 2 in which the plates and the abutment are made of wood.

11. The shuttle of claim 2 in which the plate is of elongated shape, the lonigtudinal direction thereof extending parallel to the path of movement of the shuttle, said plate 7 r 8 being bevelled away from the abutment at its forward 2,946,353 7/1960 Dunham 139125 end in the picking direction and said forward end being 3,163,184 12/1964 Cherpin 139125 rounde b 3,174,514 3/1965 Schafler 139 125 12. The shuttle of claim 2 in which said a utment is formed by a plate inserted in a wall of the shuttle. FOREIGN PATENTS 223,951 3/ 1958 Australia.

References Cited 971,273 9/1964 Great Britain. UNITED STATES PATENTS 9 2/1953 Italy,

948,945 2/1910 Smith 139126 1,729,413 9/1929 Ashton 139125 10 JAMES KEE CHI, Primary Examiner.

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