EP0077866B1

EP0077866B1 - Mechanical assembly for reciprocately driving the pliers bearing tape in a textile loom

Info

Publication number: EP0077866B1
Application number: EP81830202A
Authority: EP
Inventors: Mario Crippa
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-09-18
Filing date: 1981-10-21
Publication date: 1986-08-27
Also published as: DE3175226D1; EP0077866A1; IT1196417B; IT8124027A0

Description

The present invention relates to a mechanical assembly, effective to reciprocatingly drive the gripper bearing tape in a textile loom.
As it is known, presently in many looms the weft threads are inserted into the warp threads by means of gripper pairs, as suitably designed and driven with a reciprocating movement, in opposite directions.
Said grippers are mounted at one end of corresponding tapes, as provided with a plurality of cross slots, in such a way as to be able of engaging with planet gears.
These latter are reciprocated by means of driving mechanisms which are usually very complicated, because of the great amplitude of rotation to be transmitted to said planet gears.
For example the French Patent No. 2315559 discloses such a mechanism which comprises a large diameter pulley which drives a crank-system for transforming the rotary movement into an alternative rectilinear movement. That mechanism has the drawback of having a high inertial mass.
This fact acts against obtaining a suitable evenness in the variations and reversions of the movements of the weft inserting grippers.
Accordingly the task of the present invention is to eliminate the thereinabove cited drawback, by providing a mechanical assembly, effective to reciprocately drive the grippers bearing tapes in textile looms, having drastically reduced inertial masses.
Within said task, it is a main object of the present invention to provide such a mechanical assembly, effective to reciprocately drive the gripper bearing tapes in textile looms, which comprises a reduced number of component parts, effective to mutually cooperate, in such a way as to provide a greatly efficient and sure operating assembly.
The task and object thereinabove mentioned, as well as yet other objects which will become more apparent thereinafter are achieved by a mechanical assembly effective to reciprocatingly drive the gripper bearing tapes in textile looms, according to the characterizing part of Claim 1.
Advantageously the driving pulley of the subject assembly is mounted at one end of a high speed operating shaft, bearing a brake assembly at both ends thereof and effective to transmit movement to the two ends of the swingable shaft.
Owing to this approach the possibility is eliminated of possible torsional phenomena on said swingable shaft during the braking, which would occur in looms provided with a brake assembly at the motor or at one end only of the shaft.
The first planet gear supports an arm member or crank, on the pin thereof there is pivoted a slider, formed by two adjoining plates and effective to clamp a portion of an endless toothed belt which, through transmission members and a tension member, engages the shaft of the second planet gear, this latter meshing with the gripper bearing tape.
In a preferred embodiment in order to restrain the tapes from vibrating, which would damage the warp threads, and to control the shed opening, there is provided a device which restrains the tape only at the edge opposite to the comb, thereby said tape is able of sliding in a position nearly adhering to said comb.
Said tape guiding device consists of a L-shaped section, made rigid with the loom slay and bearing, at the free end of its horizontal wing, a plurality of vertically extending shaped plates, as evenly spaced, and provided, at the top thereof, with a parallel wall recess: at the top of the vertical wing of said section there is fixed a resilient material rectangular cross-section rod, provided with a suitably stiffened and abrasion resistant surface.
Further characteristics and advantages of the mechanical assembly effective to reciprocately drive the gripper bearing tapes in textile looms, according to the present invention, will become more apparent from the figures of the accompanying drawings, relating to a preferred and essentially indicative embodiment of the invention and where:

Fig. 1 is a schematic side view illustrating the mechanical assembly according to the present invention;
fig. 2 is a perspective view illustrating that same mechanical assembly;
fig. 3 is a detail view illustrating the fixed gear and the planetary gear as eccentrically mounted to the driven pulley;
fig. 4 illustrates the planet gear effective to transmit the reciprocating movement to the gripper bearing tape;
fig. 5 is a plan view illustrating the arrangement of the mechanical assembly on the two shoulders of a textile loom provided with a high speed operating shaft; and
fig. 6 is a cross-section view illustrating the tape guiding device.

With reference to the number references of the figures of the accompanying drawings, the mechanical assembly according to the embodiment of the present invention comprises a toothed pulley 1 driven, through a belt 2 or other suitable driving member, by a driving pulley 3 driven by a driving shaft 3' of the loom.
The toothed driven pulley 1 eccentrically supports the shaft 4 of a planet gear 5, meshing with the teeth of an internal gear 6, as fixed, cantilever- wise, on the shoulder 7 of the loom.
Said planet gear 5, in turn, rigidly supports a crank 8 to the pin thereof there is pivoted a slider 9, formed by two adjoining plates and able of sliding within guides formation as provided at the outer end of the crank 8.
The slider 9 is effective to clamp a portion of a toothed belt 10 which, through transmission members 11 and a tension member 12, engages the shaft 13 of a further planet gear 14.
Practically, by rotating the pulley 1, the shaft of the planet gear 5 moves on a circular path, in such a way that said planet gear is able of meshing with the teeth of said fixed internal gear 6.
Accordingly, this latter is driven with a planetary movement, in such a way as to cause the pin of the crank 8 to rectilinearly reciprocate.
The slider 9, therefore, drives, with a like reciprocating movement, the toothed belt 10, thereby causing the planet gear 14 to rotatively reciprocate.
This latter engages the gripper bearing tape 15, restrained in the guide 16, thereby causing said tape to reciprocate.
It is moreover provided the possibility of replacing the direct fixing of the slider 9 by connecting rods, in such a way as to vary the stroke of said gripper bearing tape.
Advantageously, said driving pulley 3 is mounted at one end of a high speed operating shaft 17, bearing at both ends thereof a braking assembly 18, effective to transmit movement to the two ends of the swingable shaft 19.
Moreover, it is possible to provide for the use of a tape guiding device 20, formed by an L-shaped section member 21 made rigid with the loom slay 22.
The vertical wing 21' of said section member is located at one side of the loom comb 23 and supports, at the top thereof, an elastomeric or plastics material rod 24, provided with a suitably stiffened and abrasion resistant surface.
On the free edge of that same section member there are fixed a plurality of shaped plates 25 as evenly spaced at adjoining positions.
These plates are provided with a top recess 26 in such a way as to jointly provide a sliding guide effective to restrain an edge of the tapes 27 bearing the grippers 28.
It should be noted that the aforesaid resilient material rod 24 is located at a slightly lower level than the theoretical sliding plane of said tapes, in order not to hinder the passage of the warp threads 29, not rised by the heddles.
That same rod, anyhow, advantageously acts as a damping member, against possible vibrations of said gripper bearing tapes.

Claims

1. A mechanical assembly effective to reciprocatingly drive the gripper bearing tapes in textile looms, comprising a toothed driving pulley (3) driven by a driving shaft (3') of said loom, a crank-rod system (5, 6, 8, 9), and means for transmitting the reciprocating movement of the crank-rod system (5, 6, 8, 9) to a gear member driving the gripper bearing tape, characterised in that said crank-rod system comprises a gear wheel (5) meshing with the inside toothed surface of a fixed ring gear (6), an arm member (8) fixed to said gear wheel (5), a slider (9) rigid with a toothed belt (10) and swivel supported at one end of said arm member (8), said belt (10) engaging with a gear wheel (14) driving said gripper bearing tape (15), and in that said assembly further comprises a toothed driven pulley (1) eccentrically rotatably mounting said gear wheel (5) through a shaft member (4), said driven pulley laying substantially in the same vertical plane as said driving pulley (3), a toothed belt (2) being provided entrained about said driving pulley (3) and said driven pulley (1) to rotate said driven pulley (1) and said gear wheel (5) in such a way as to cause said slider to reciprocate in a substantially vertical plane.

2. A mechanical assembly according to claim 1, characterized in that said driving shaft (3') is provided with a respective braking assembly at each end thereof, said slider (9) consisting of two adjoining plate members therebetween there is clamped a portion of the toothed belt (10).