US3580291A

US3580291A - Filling carrier for use in shuttleless looms

Info

Publication number: US3580291A
Application number: US750267A
Authority: US
Inventors: Mario Piccoli
Original assignee: SOMET Societa Meccanica Tessile SpA
Current assignee: Promatech SpA
Priority date: 1967-09-19
Filing date: 1968-08-05
Publication date: 1971-05-25
Anticipated expiration: 1988-05-25

Abstract

A feeding gripper that transfers weft yarn to a drawing gripper in the warp sheds of a shuttleless loom comprises an open boxtype structure or main body of plastic with a laterally projecting front wing. The wing is bifurcated by a forwardly opening horizontal slot, into superposed lower and upper jaws that receive between them the weft yarn. The upper jaw is in two laterally spaced portions one of which extends forwardly from the forward end of the main body and the other of which, at a lower level, overlies the lower jaw. The forward ends of the two portions of the upper jaw are interconnected by a downwardly laterally outwardly inclined portion, and a vertical fin having a forwardly downwardly inclined upper edge is disposed on the inner side of the forward end of the lower jaw. A resilient yarnchecking device is provided on the lower jaw, between the two portions of the upper jaw, comprising metallic laminae and an adjustable leaf spring which presses them against the lower jaw.

Description

United States Patent [72] Inventor Mario Piccoli Gazzaniga, Italy 21 1 App]. No. 750,267

[22] Filed Aug. 5, 1968 [45] Patented May 25, 1971 [73] Assignee Somet S.p.A. Societa Meccanica Tessile Gazzaniga, Italy [32] Priority Sept. 19, 1967, Mar. 6, 1968 [3 3] Italy [31] 20,635/67 and 13,607/68 [54] FILLING CARRIER FOR USE IN SHU'I'I'LELESS LOOMS 1 Claim, 9 Drawing Figs.

[52] US. Cl 139/122 [51 Int. Cl D03d 47/20 [50] Field ofSearch l39/122,1, 127

[5 6] References Cited UNITED STATES PATENTS 3,081,796 3/1963 Remington 139/122N 3,159,186 12/1964 Juillard 139/127 3,390,707 7/1968 Scherillo 139/122N FOREIGN PATENTS 1,444,834 5/1966 France 139/122N Primary Examiner-Henry J. J audon Attorney-Young and Thompson ABSTRACT: A feeding gripper that transfers weft yarn to a drawing gripper in the warp sheds of a shuttleless loom comprises an open box-type structure or main body of plastic with a laterally projecting front wing. The wing is bifurcated by a forwardly opening horizontal slot, into superposed lower and upper jaws that receive between them the weft yarn. The upper jaw is in two laterally spaced portions one of which extends forwardly from the forward end of the main body and the other of which, at a lower level, overlies the lower jaw. The forward ends of the two portions of the upper jaw are interconnected by a downwardly laterally outwardly inclined portion, and a vertical fin having a forwardly downwardly inclined upper edge is disposed on the inner'side of the forward end of the lower jaw. A resilient yam-checking device is provided on the lower jaw, between the two portions of the upper jaw, comprising metallic laminae and an adjustable leaf spring which presses them against the lower jaw.

Patented May 25, 1971 2 Sheets-Sheet 1 Patented May 25, 1971 3,580,291

2 Sheets-Sheer, 2

FILLING CARRIER FOR USE IN SIIU'I'ILELESS LOOMS BACKGROUND OF THE INVENTION This invention relates to an improved carrier gripper for continuous weft supply looms.

As is known, in shuttleless looms with continuous weft supply the shuttle is replaced by a pair of carrier grippers, said grippers mutually and alternately moving away from and drawing near to each other. The first of said grippers, namely the feeding gripper, is adapted to grasp the weft threads at one end of the loom immediately out of the sheds and to carry them inside said sheds up to an intermediate zone, whereas the second of said grippers, namely the drawing gripper, is adapted to partially penetrate inside a seat of the feeding gripper to pick up said weft threads from said zone and carry them in its turn to the other loom end, outside the sheds, and leave them there.

The present invention increases the weft supply speed, that is the gripper speed. But this speed increase is limited on one hand by the high inertia due to the reverses of the gripper movement, and on the other hand by the need to prevent as far as possible the nongrasping or nonholding of the weft threads. Therefore, any loom improvement will have to take into consideration the reduction in the gripper weight and the increase in the reliability of the grasping and holding means of the weft threads to be carried. Another advantage derives from a reduction in the friction due to the gripper movement.

For the reasons already stated, this invention provides an improved feeding gripper by the use of which important advantages may be obtained in the operation of continuous weft supply looms and particularly a substantial increase in the speed of the looms.

SUMMARY OF THE INVENTION The gripper according to the invention is of the above-mentioned type and is characterized in that said gripper includes a stiff gripper body obtained by moulding of plastic synthetic material, and elastic or elastically acting metallic elements mounted on said body and adapted to cooperate with portions of the same especially arranged to grasp and/or hold said weft threads or yarns.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be better described by way of example, with reference to the enclosed drawings in which:

FIG. 1 is a perspective view with disassembled portions of the feeding gripper according to the invention with its own support;

FIG. 2 is a side view of the FIG. 1 gripper with some portions represented in section and others removed;

FIGS. 3, 4 and 5 are views of the front side, from the top, and of the rear side of the gripper of FIGS. 1 and 2;

FIG. 6 is a perspective view of the gripper of FIGS. 1 and 2 with removed portions, which illustrates the engagement between the gripper and the weft yarn; this gripper is provided with laminae and a leaf spring both having forked ends;

FIG. 7 is a side and top view of a forked leaf spring like that illustrated in FIG. 6;

FIG. 8 is a side and top view of the corresponding metallic lamina; and

FIG. 9 is a perspective view with removed portions of a further embodiment of the feeding gripper according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The filling carrier or feeding gripper 1, according to the invention, (FIGS. 1 to 8) includes a main body or gripper body 2 of a complex open box-type structure, obtained by moulding of plastic synthetic material, the above structure being very light and stout, completely smooth and with very low friction supporting surfaces. Said gripper body 2 comprises in a known manner an upper jaw 3 and a lower jaw 4, the weft yarn F being received between the above jaws. According to the invention the lower jaw 4 has no conventional warp protecting rear edge, which is replaced by a vertical fin 5 ensuring protection from below, and by a lightly'forward and downward beveled portion of the upper jaw 3 ensuring protection from the top. Fin 5 is arranged on the rear side of the lower body portion 4, from which it projects vertically upwards, substantially along an axis just offset in respect of the longitudinal axis of the inserting member. The rear side of the gripper body 2 has a V-shaped slanting slit 6 for the weft yarn, said slit being protected at its apex by a metallic insert 6', which reduces wear on the plastic material of which said gripper is made. At the front side the weft yarn enters into slot 7 which separates the upper jaw 3 from the lower jaw 4. Also for this slot a metallic insert 8 is provided at the junction of 3 and 4 jaws in the body 2. The gripper body is formed in one single box-type piece, having a side wing projecting from the front side, and this body splits up into two body portions on the forward part of the gripper, of which the upper body portion 3 is formed by the upper side of the box-type piece and by a first half of the wing, and the lower body portion is formed by an extension of the front side of the box-type piece and by the lower half of the wing. The slit 7 is made between the lower and upper portions of the wing. I

Stated another way, the present invention comprises an open box-type structure or body 2 of plastic with a laterally projecting front wing 20. The wing 2a is bifurcated by a forwardly opening horizontal slot 7, into superposed lower and upper jaws 4 and 3 that receive between them the weft yarn F. Upper jaw 3 is in two laterally spaced

portions

3a and 3b. Portion 3a extends forwardly from the forward end of body 2. Portion 3b is disposed at a lower level than portion 3a and overlies lower jaw 4. The forward ends of portions 311 and 3b are interconnected by a downwardly laterally outwardly inclined portion 30. Vertical fin 5 is disposed on the inner side of the forward end of lower jaw 4 and has a forwardly downwardly inclined upper edge 5a.

Moreover, gripper 1 includes a resilient metallic element 9 cooperating with the gripper body 2 for the grasping and holding of the weft yarn. Such element consists of one or more steel laminae 10 held against to the upper surface of the lower jaw 4 by a leaf spring 11, the coupling force of which may be controlled by adjusting screw 12, the latter also ensuring the assembly of element 9 on the body 2 by means of nut 13. A resilient washer is provided (not shown) so as to prevent undesired movements of screw 12. On the surface of the lower jaw 4, preferably in the area where laminae 10 are engaged a thin flat, metallic insert is provided to prevent wear.

The gripper body 2 is fixed within a support S of the same plastic material, as shown in FIG. I. Said support S is in turn mounted at the end of the strap that causes the alternate movement of gripper l in a known manner.

Number 14 in FIG. 1 indicates a small block guiding the FIG. 1 assembly into the loom sheds.

In the event that the gripper should be designed to work with fine and delicate yarns, it is moreover convenient to provide the rear side of the lowest lamina 10 with a plastic or the like lining so as to prevent the lamina edge from acting like a knife on the weft yarn when the latter is stretched during the gripper movement towards the loom sheds.

It is also useful to adopt forked laminae as those shown in FIGS. 6 and 8, in which case a leaf spring will be adopted, also forked like the one in FIGS. 6 and 7. The advantage of this arrangement consists in achieving two separate points of engagement of the weft yarn with increased safety and a more efficient grip. Also a certain effect of self-cleaning during use is obtained and the jamming due to dust or dirt is further reduced. As may be seen, in order to achieve two points of engagement of the thread, in oblique alignment with the ripper, the leaf is made of a shorter branch (which is arranged outwardly of the gripper) and a longer branch (which is arranged inwardly) on the side, that is, which first receives the weft yarn.

When working with fine yarns and at a high speed it is very useful to employ a retaining spring as shown in FIG. 9 placed parallel to and upwards (in respect to the weft yarn course) of the lamina 10. The said spring is adapted to avoid undesired loosenings of the weft yarn on the hook of the grasping gripper when the two grippers exchange the yarn.

ln loom operation, the pair of grippers acts substantially like the known type grippers. The feeding gripper of this invention grasps the weft yarn at one end of the loom sheds gripping it between 3 and 4, holding it for cutting and conveyance between 10 and 4 until an oppositely moving grasping gripper (not shown) grasps in turn the yarn midway of the sheds and carries it to the other end of the loom where the yarn is freed through the action of a freeing plate (not shown).

However, in the above functions the described and illustrated arrangement offers many advantages compared to those of the prior art.

First of all the use of plastic material (preferably of the type known in trade as Nylon or the like) allows a remarkable reduction in the grippers weight and a great increase in their smoothness of movement on the corresponding loom parts and on the warp yarn, therefore making it possible to increase the loom speed without any risk. The driving straps stress as well as the stress of the mechanical means controlling them and the wear of said straps will in fact be reduced, compared with the standard values, in such a big way as to ensure a surprisingly high increase in the loom speed. Such increase can reach values higher than 65 percent.

For example in a loom having a sley of 2.40 meters and operating at a speed of I beatings up per minute, it has been possible to obtain a speed of 200 beatings up per minute by merely substituting the standard metal grippers with the grippers according to this invention.

The reduced friction against the warp yarns when the grippers enter the sheds and cross them and come out of them,

even allows a widening of the utilization field of the continuous weft supply looms. It is in fact known that, up to the present, it has not been possible to work on these looms with fibers of the rayon type and others which broke under the action of the heat due to friction, in particular as regards thin counts. This inconvenience'is avoided by the gripper according to the invention, the friction of said gripper with the above materials being so reduced that the described phenomenon is prevented.

It should also be noted that the stiffness of the gripper body according to the invention is much lower than that of similar metal devices: this allows on one hand a better sealing of the elastic metal elements on the cooperating portions of these bodies because of their compliance, and therefore a higher reliability of weft yarn grasping and holding (the thin metal linings against the wear of these portions do not alter the substance of things). On the other hand, the contacts and impacts (always possible during operation) between the grippers take place without serious inconveniences due to the yield of impacting bodies, with obvious advantages as far as the bodies life and preservation and maintenance is concerned. Furthermore, the gripper according to the invention does not undergo the damages (not to be disregarded) to which normal grippers are subject as a result of atmospheric and chemical corrosion.

As far as the gripper according to the invention is concerned, the advantage of a better profiling of the gripper claws is added to the advantages already mentioned. This better profiling helps the movement of the gripper inside the sheds.

It is understood that the invention is not limited to the embodiments herein illustrated and described in detail by mere way of example, the scope of the invention being defined by disposed at a lower level than said one portion and overlies said lower jaw, the forward ends of said two portions of said upper jaw being interconnected by a downwardly laterally outwardly inclined portion, a vertical fin on the inner side of the forward end of said lower jaw, said fin having a forwardly downwardly inclined upper edge, a resilient yarn-checking device on the lower jaw between said two portions of said upper jaw, said resilient device comprising at least one metallic lamina and an adjustable leaf spring which presses said lamina against the lower jaw.

Claims

1. A feeding gripper for transferring weft yarn to a drawing gripper in the warp sheds of a shuttleless loom, comprising an open box-type main body having thereon a laterally projecting front wing bifurcated by a forwardly opening horizontal slot into superposed lower and upper jaws that receive between them the weft yarn, said upper jaw being in two laterally spaced portions one of which extends forwardly from the forward end of said main body and other other of which is disposed at a lower level than said one portion and overlies said lower jaw, the forward ends of said two portions of said upper jaw being interconnected by a downwardly laterally outwardly inclined portion, a vertical fin on the inner side of the forward end of said lower jaw, said fin having a forwardly downwardly inclined upper edge, a resilient yarn-checking device on the lower jaw between said two portions of said upper jaw, said resilient device comprising at least one metallic lamina and an adjustable leaf spring which presses said lamina against the lower jaw.