DEVICE TO CHECK THE WARP CHAIN IN WEAVING LOOMS

Abstract: Warp stop motion device - of the type comprising lateral and intermediate supports (1), drop wires (3) for checking the warp yarns (f, f′) rows (2) interacting with the drop wires (3), and separation irons (4) - wherein the separation irons (4) are mounted on brackets (5) of the supports (1), said brackets be­ ing pivoted to said supports in order to be able to vary, by ad­ justment, the lie of the two laps of the warp chain upstream of the healds (13).

Description: "DEVICE TO CHECK THE WARP CHAIN IN WEAVING LOOMS" In the technique of weaving Looms, it is well known to make use of devices for checking the warp yarn chain, which are meant to stop the loom when, for any reason, the warp yarn breaks off. These devices, commonly called warp stop motion devices, influence with their positioning the proper working of the loom. It often happens, in fact, that a certain positioning of the warp stop motion device may cause breaks in the warp yarns checked by said device. Contrasting requirements, in view of the proper working of the loom, do not allow to find a satisfactory arrangement of the warp stop motion device, according to the different loom performances. The present invention proposes to improve the working of the warp stop motion device by improving its structure, so that it can be easily adapted to the requirements of each weaving operation, just as if the most suitable positioning were each time chosen for said device. For this purpose, the invention provides for a warp stop motion device allowing, through mutuaL adjustment of some of its parts, to vary the lie of the two laps of the warp yarn chain upstream of the healds. Said warp stop motion device - of the type comprising Lateral and intermediate supports, drop wires for checking the warp yarns, rows interacting with the drop wires, and separation irons - is characterized in that, in each support, the separation irons are mounted on a bracket, pivoted close to the inlet of the chain of warp yarns fed from the beam, said bracket being caused to oscillate along a short arc in respect of said support, and in that, means are provided to lock the bracket in respect of the support in a given position along said oscillation arc. The invention will now be described in further detail, by mere way of example, with reference to the accompanying drawings, in which: Fig. 1 shows the arrangement of a conventional warp stop motion device; Fig. 2 shows the arrangement of a warp stop motion device according to the invention; and Fig. 3 is a detailed diagrammatic side view of a support for the warp stop motion device according to the invention. In the warp stop motion device according to the invention, each lateral or intermediate support 1 carries - as clearly shown in figure 3 - the rows 2, interacting in known manner with the drop wires 3, which check the yarns f and f' of the warp chain (see figure 2). The separation irons 4 are instead mounted on a bracket 5, pivoted in 6 on the support 1, close to the inlet of the warp yarns f and f' fed from the beam 7 of the loom. The various supports 1 of the warp stop motion device are stiffened by a tube 8, while a tube 9 mutually connects the brackets 5 of the different supports 1. The tubes 8 and 9 also carry locking means, consisting of screws 10 and 11, for fixing respectively the desired positions chosen for the supports 1 and the positions of the brackets 5 in respect of said supports 1. By this arrangement, the position of the brackets 5 in respect of their supports 1 can be adjusted within a short oscillation arc about the pivot 6, as shown in figure 3 wherein the two extreme positions taken up by the bracket 5 are represented by the tube 9, drawn in continuous lines and, respectively, in dashed lines. Compared to the conventional warp stop motion device of figure 1 which, once positioned, allows only one possibility of lie of the two laps of the warp yarn chain, the warp stop motion device according to the invention (figure 2) allows to choose the lie of the lower lap over a fairly wide arc, by varying the inclination of the plane tangent to the separation irons 4 and to the tube 9, through oscillation of the bracket 5 - in respect of the fixed part of the support 1 - about the pin 6. Figure 2 shows, in full lines, the position of strongest inclination of the bracket 5 and it also shows a supplementary tube 12, which prevents the yarns of the upper lap of the warp from pressing against the rows 2. In this way, it is possible to widen to a considerable extent the outlet wangle between the two laps of the warp yarn ch-r, from the warp stop motion device upstream of the healds 13 - as clearly seen on comparing figures 1 and 2 - and this allows substantial reciprocal alternating movements between the yarns along the whole stretch checked by the warp stop motion device, during working of the loom. Such movements prevent dust deposits between the drop wires of the warp stop motion device, tending to clog the passages for the yarns and often causing the breaking thereof; moreover, the path followed by the warp yarns thus becomes straighter. It is understood that the invention could also be carried out with other embodiments, differing from that described which has been given by mere way of non-limiting example. For instance, an equivale nt solution could be to connect the separation irons to the supports and to mount the rows for the drop wires on brackets pivoted to said supports and oscillating to be fixed in a suitable chosen position.

Claims: CLAIMS 1) Warp stop motion device - of the type comprising lateral and intermediate supports (1), drop wires (3) for checking the warp yarns (f,f'), rows (2) interacting with the drop. wires (3), and separation irons (4) - characterized in that, in each support (1), the separation irons (4) are mounted on a bracket (5), pivoted close to the inlet of the chain of warp yarns fed from the beam (7), said bracket (5) being caused to oscillate along a short arc in respect of said support (1), and in that, means (10,11) are provided to lock the bracket (5) in respect of the support (1) in a given position along said oscillation arc. 2) Warp stop motion device as in claim 1), wherein said means for locking the bracket (5) in respect of the support (1) consist of screws (10,11).

Inventors: PEZZOLI, LUIGI
Applicants: VAMATEX S.P.A.
Application year: 1986
Main classification: D03D51
IPC codes: D03D51