FR2520011A1 - Weft-selector mechanism for shuttleless loom - holds ladder-like array of yarns at adjustable height - Google Patents

Abstract

A weft selector mechanism for a shuttleless loom comprises a vertical, essentially rectangular frame down one side of which are a series of yarn holders, with a corresponding series of guide eyes down the other side through which the different yarns are passed into the holders, forming a ladder-like array of yarns which straddles the path of the weft-inserter. A rack and pinion mechanism driven by a step motor enables the height of the frame to be adjusted by precise increments, such that a particular yarn can be presented to the weft inserter as it advances into the shed. This is a simple, reliable mechanism of low mass and with few moving parts, facilitating high-speed operation.

Description

 The present invention relates to a selection and presentation device for weft threads in front of the insertion member in a loom. Such a device is generally known by the name of "Color selector", given that during the weaving operation on the loom, it can successively present threads of different colors to the insertion member.

It is understood that the term "inserting member" can be taken in its most general sense. It can in particular be a lance or a weft puller of the kind of those which 'we use on looms of the type known as' without shuttle'. The invention therefore relates generally to a weaving loom having on one side or on both sides, several spools or weft reserves mounted on fixed supports o The problem is to present to the insertion member before propelling it into the ditch, a weft thread coming from one or 11 other of the weft reserves
We oonnatt various mechanisms of color selector. All have in common the fact of implementing relatively heavy and complicated mechanical parts, which limits the possibilities of speed of the trade. In addition, their complication and the large number of moving parts give them generally poor endurance performance. Finally, their control system is generally dependent on the other functions of the machine, which prevents them from being adapted on a sequenced machine.

The object of the present invention is to avoid these drawbacks by making a device for selecting and presenting the weft threads, the production of which is particularly simple and robust, while being suitable for mounting on a sequenced machine operating at high speed.
A device according to the invention, intended to present to a weft insertion member, one or the other of the threads coming from several fixed weft reserves situated on at least one side of a weaving machine, is characterized in that it comprises a support on which are stretched side by side several wires each coming from one of the weft reserves, while means are provided for moving this support at will across
the path of the insertion member of the weaving machine, these
means comprising inter alia a stepping motor
According to another characteristic of the invention, the eupport has this in the form of a fork, the base of which comprises
means actuated by the stepping motor to move it in one direction or the other, according to an amplitude to be defined for each
that displacement, while between its branches, are stretched
one above the other, the various weft yarns waiting
you
Following another characteristic of the invention, one
branches of the fork has several superimposed clamps,
intended to each receive the end of one of the weft threads
waiting, alers that the other branch is carrying eyelets of mistletoe
overlapping dace t each of which is crossed by the weft thread in
corresponding wait.

The attached drawing, given by way of nonlimiting example,
will allow places to understand the characteristics of the invention.

Figure 1 is a front view of a selector device
according to the invention, the plane of the figure being perpendicular to
the trajectory of the weft puller.

 Fig @ re 2 is a corresponding plan view.

Figures 3 to 5 illustrate the different successive phases
of operation.

A compor loom has been represented on the drawings
as an insertion member 1 of known type, which moves during
the rectilinear trajectory 2 which he describes from coast to coast of
job . In the case of Figure 1, the path 2 is per
pendulum to the drawing plane, so that it is schematized
by a p @ int.

At the front, the weft puller 2 has a clamp 3 of the type
known, which can be, depending on the case, with automatic operation
or ordered. When the insertion member 1 moves in the direction
indicated by arrow 4 (figure 3), i.e. before being launched
in the crowd, we present him with one of the weft threads such as
5, 6, 7, 8, from several tame frame reserves that
9, 10, 11, 12, fixed station mounted @ on the side of the loom.

The device according to the invention relates to the selection and
the presentation of one or other of the milking wires, such as 5
at 8, in front of the clamp 3 of the weft puller 2, before colui-ci is
launched into the crowd.

The device comprises a movable fork 13, the two branches 14 and 15 of which are integral with a leg 16 0 The latter is capable of sliding freely in guide bearings 17 o It is provided laterally with a control member 18 which may for example be a rack o This permanently meshes on the pinion 19 of a stepping motor 20. The motor 20 can turn on command in one direction or the other, according to an amplitude corresponding to a chosen number of increments
Along the branch 14 are superimposed clamps 21 with automatic operation. Each of these clamps is constituted in the known manner by two elastic fingers between which the end of the wire 5 s 6, 7 or 8 considered is retained.

 On the other hand, along the branch 15 are superimposed several eyelets 22 each traversed by the corresponding weft thread 5 to 8, which can slide there freely.

The operation is as follows
Each of the wires 5 to 8 is stretched between the two branches 14 and 15 of the fork 13. By pulses determined as a function of the machine cycle on the one hand, and on the other hand - ,. according to a program corresponding to the choice of selection according to the weaving pattern, the motor 20 is caused to rotate in one direction or the other, in one or more increments. It is therefore possible to raise or lower the assembly of the fork 13 and of the wires 5 to 8 which it carries. This makes it possible to place facing the path 2 of the weft-pulling member 1 g that of the wires 5 to 8 which 'we want to introduce into the crowd. For example, we see in Figure 3 the configuration of the device if we want to present the wire 6 to the weft puller 1. As soon as it has started moving in the direction of arrow 4, the clamp 3 grasps the wire 6 (Figure 4) and then introduces it into the crowd by unwinding it from its frame reserve, as shown by the arrow 23.

If on the other hand, in another cycle of the metisr, it is desired to present the weft puller 1 the wire 8, it suffices to actuate the stepping motor 20, to lift the fork 13 by the corresponding quantity (arrow 24, FIG. 5 )
It can be seen that the system according to the invention has the following advantages in particular - simplicity of construction - small number of mechanical components - few moving parts, therefore little wear and satisfactory endurance
doing (only the fork 13 and Re motor 20 are moving);
- low mass to move, which consumes little energy and allows
a very fast operating rate
- pulse control, making this function independent of
other functions of the machine, so that it is adaptable to
a sequenced machine; ;
- you can change the number of weft threads 5 to 8, without changing
the dispoeitif;
this system does not impose any limitation on the choice of program,
made his command by successive pulses
- small footprint ;
- very modular system
Of course, the rack system 18 can be replaced by a mechanism of known type, called "capstan", the roller is rotated by the pinion 19, while a cable is wound on this roller to which it is fixed. by a point.

Claims (5)

 1 - Device intended to present one or more of the threads to a dtinser- tion organ that processes from several fixed weft reserves, located at least on one side of a weaving machine, characterized in that 'it includes a support on which are stretched side by side several wires such as (5), (6), (7), (8) 2 each coming from one of the weft reserves (9), (10) ( 11), (12), while means are provided for moving this support at will across the trajectory (2) of the insertion insert (1) t of the weaving machine 2 these means comprising inter alia, a stepper motor (20).  2 - Device according to claim 1, characterized in that the support is in the form of a fork (13) whose foot (16) comprises means actuated by the stepping motor (20), in order to move it in one direction or the other, lon an amplitude to be defined for each movement r while between these branches (14) and (15) are stretched one above the other t the various weft yarns waiting (5 ), (6) * (7), (8).  3 - Device according to claim 2, characterized in that the branch (14) of the fork (13) comprises several clamps (21), superimposed, each intended to receive the end of one of the waiting weft threads ( 5) E (6) f (7), (8) f while the other branch (15) of the fork (13) carries superimposed eyelets (22) each of which is crossed by the corresponding weft yarn ( 5), (6), (7), (8), to guide it.  4 - Device according to any one of the preceding claims, characterized in that the step-by-step motor (20) is equipped with a pinion (19) which it drives in rotation by successive increments in one direction or in the 'other, this pinion (19) being meshed on a rack (18) integral with the fork (13).  5 - Device according to any one of the preceding claims, characterized in that the pinion (13) drives a roller on which is wound the char of a known mechanism, called "capstan".