[0001] 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.
[0002] These devices, commonly catted 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] In this way, it is possible to widen to a considerable extent the outlet angle between
the two Laps of the warp yarn chain, 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.
[0013] 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.
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).