[0001] The present invention concerns a pair of weft grippers for shuttleless looms, namely
a pair of members by means of which the weft yarns are inserted at one end of the
loom and carried to the opposite end thereof through the warp shed.
[0002] The present invention particularly concerns improvements in a pair of weft grippers,
of the type in which the weft yarn is retained by engagement of the head of a slider,
movable longitudinally to the gripper, with a cooperating counteracting surface of
the body of said gripper, said slider being stressed by a spring.
[0003] Up to date, the slider in these grippers has always been released by stretching an
element with flexible lamina controlling the same, through winding of said element
onto a cylindrical pin or - more recently - onto a cam with a slightly curved contour
(see for example the European Patent Application No. 85106398.2 of the same Applicant),
said pin or cam being caused to rotate by a release lever carried by the gripper body
and rotated in turn by a fixed element of the loom engaging therewith. In these constructions,
the flexible control element is always highly and frequently stressed, and it tends
to fatigue break after a more or less long period of use of the grippers, with evident
damage for the production requirements.
[0004] The object of the present invention is to eliminate this drawback by supplying, for
the purpose, a pair of grippers - a carrying and, respectively, a drawing gripper
- of the aforementioned type, characterized in that, in each gripper, the release
of the slider against the action of the spring stressing the same is obtained by direct
engagement of a snug of said release lever with a pawl fixedly connected to the slider.
[0005] Preferably, said pawl fixedly connected to the slider also supports the spring stressing
said slider.
[0006] The invention is now described in further detail, by mere way of example, with reference
to the accompanying drawings, in which:
Fig. 1 is a comprehensive perspective view of a carrying gripper according to the
invention;
Fig. 2 is a comprehensive perspective view of a drawing gripper according to the invention;
and
Fig. 3 is a sectional view, on an enlarged scale, showing the mechanism for operation
and release of the grippers of figures 1 and 2 according to the invention.
[0007] The pair of weft grippers according to the invention comprises the carrying gripper
P of figure 1 and the drawing gripper T of figure 2. Both these grippers have a general
structure of known type, which comprises a body 1 of highly rigid synthetic plastic
material, into which is mounted a metal slider 2 moving longitudinally, said slider
being stressed by a spring 3 towards the tip 4 of the body 1, so as to engage with
its own head 5 a counteracting surface 6 of said body and lock the weft yarn t between
these two elements 5 and 6.
[0008] According to the invention, in the structure of both these grippers (figure 3) the
slider 2 is moved away from the surface 6, against the action of the spring 3, by
engagement of a snug 7 of the common release lever 8 into the seat 10 of a pawl 9,
this latter being fixedly connected to the slider 2 and acting as support for the
spring 3.
[0009] The snug 7 is preferably formed in one piece with the lever 8.
[0010] In this way the lever 8, pivoted in 11 onto the gripper body 1, controls directly,
and without any particularly high stresses, the release of the slider 2 (and thus
of the gripper) when - in known manner - it is caused to rotate (counterclockwise,
looking at figure 3) by a fixed control element (not shown), provided for the purpose
on the loom, engaging with its conventional curved portion 8A.
[0011] It is evident that a control device for the slider, thus conceived, not only prevents
the drawback of fatigue breaks - characteristic of previous mechanisms comprising
flexible lamina elements - but also makes the slider far more precise and direct,
avoiding any uncertainties in the control which, in known structures, were determined
by the deformability and resiliency of the flexible lamina.
[0012] Furthermore, the grippers adopting this device are far lighter and more compact,
as they can be constructed with positively reduced dimensions and weights, thereby
achieving important advantages especially on looms with high working speed.
1) A pair of weft grippers for looms, of the type in which the weft yarn is retained
by engagement of the head of a slider, movable longitudinally to the gripper, with
a cooperating counteracting surface of the body of said gripper, said slider being
stressed by a spring and being released under control of a lever operated by an element
fixed to the loom, characterized in that, in both grippers, the release of the slider
against the action of said spring is obtained by direct engagement of a snug of said
lever with a pawl fixedly connected to the slider.
2) Pair of grippers as in claim 1), wherein said pawl fixedly connected to the slider
also supports the spring stressing said slider.
