GB2465744A

GB2465744A - Rapier loom drive mechanism

Info

Publication number: GB2465744A
Application number: GB0820135A
Authority: GB
Inventors: John Dalton Griffith
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-04
Filing date: 2008-11-04
Publication date: 2010-06-02
Also published as: CN101736494A; GB0820135D0; CN101736494B

Abstract

A drive mechanism for a rapier (48, figure 4) and beat-up reed 24 comprises a linkage reciprocally driven by drive shaft 1. The linkage includes first 20 and second (40) reciprocally driven outputs. The first output drives the reed between beat-up and retracted positions. The second output reciprocates the rapier in synchronism with reed. Preferably main drive link 6 reciprocates about first pivot 13 and reed link 9 reciprocates about second pivot 7 to between reed beat-up and retraction. Preferably rapier link 10 is pivoted at third pivot 8 on the main drive link to reciprocate in synchronism with the reed link 9 between rapier insertion and retraction. The first output is preferably a crank arm 20 pivoting on a reed shaft 21 and pivotally connected to the reed link at a fourth pivot 11 to cause reciprocal movement of the crank arm when the reed is reciprocated. Preferably the second output comprises a linearly reciprocal drive member (40) connected to the rapier link 10 by a fifth pivot 12. Drive member (40) is preferably clamped to a timing belt trained about idler (43, 44, 45) and drive (46) pulleys to insert and retract a tape rapier wound about a sprocket (47).

Description

DRIVE MECHANISM

The present invention relates to a rapier loom and to a drive mechanism for a beat-up reed and rapier in a rapier loom.

Weaving looms are well known which include a rapier that reciprocates across the warp sheet for inserting a weft yarn into the shed. The rapier resides to one side of the warp sheet and is inserted into and out of the shed in synchronism with the beat up reed.

Usually the drive to the rapier and the drive to the beat-up reed takes the form of a series of cams and gears. These components can be complex and costly.

A general aim of the present invention is to provide a drive mechanism which minimises the use of cams and gears and which provides a simpler low cost alternative to driving the beet-up reed and rapier in synchronism.

A more specific aim of the invention is to provide a drive mechanism which dispenses with the use of cams and gears entirely.

According to one aspect of the present invention there is provided a drive mechanism for a rapier and beat-up reed of a rapier loom, the drive mechanism being defined by a mechanical linkage which is adapted to be reciprocally driven by a drive shaft of the loom, the mechanical linkage including first and second reciprocally driven outputs, the first output being adapted to be connected to the reed of the loom to drive the reed between reed beat-up and reed retracted positions and the second output being adapted to be connected to the rapier of the loom so as to reciprocate, in synchronism with the reciprocal movement of the reed, the rapier between a rapier inserted position and a rapier retracted position.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which:-Figures 1 to 3 are end views of a mechanism according to an embodiment of the invention showing the mechanism in different operating positions, Figure 4 is a front view of the mechanism shown in Figures 1 to 3; and Figure 5 is a more detailed perspective view of part of the mechanism shown in Figures 1 to 3.

In the drawings there is shown part of a rapier loom RL having a frame side plate 30, a reed shaft 21 rotatably mounted in the side plate 30 via a bearing 25 (the shaft 21 extends across the width of the loom and is similarly mounted in a further frame side plate), a reed slay 23 fixedly mounted on the reed shaft 21 by a series of arms 22 spaced along the shaft 21 (only one of the arms 22 being shown), a beat-up reed 24 mounted on the reed slay 23, a tape rapier 48 and a rapier drive mechanism 110.

The rapier drive mechanism 110 includes a drive sprocket wheel 47 about which the tape rapier 48 is wound such that rotation of the sprocket wheel 47 in one direction causes the rapier 48 to be inserted into the shed S defined between the warp yarns 51,52 and rotation in the opposite direction causes the rapier 48 to be retracted from the shed S. The sprocket wheel 47 is rotatably driven in a reciprocatory manner by a timing belt 42 which is trained about idler pulleys 43,44,45 and a drive pulley 46 which is drivingly connected to the sprocket wheel 47. The timing belt 42 is driven in a reciprocatory manner by a drive member 40. The drive member 40 is clamped to the timing belt 42 and is constrained to slide in reciprocatory manner along a rectilinear slide guide 41.

The sprocket wheel 47, idler pulleys 43,44,45, drive pulley 46 and slide guide 41 are all mounted on a mounting bracket 50 which in turn is fixedly secured to a reed shaft drive crank arm 20. Accordingly the mounting bracket 50 (and all components mounted on it) reciprocally move with the reed shaft 21 as it rotates in a reciprocal manner.

A drive mechanism according to an embodiment of the present invention is shown generally at 100 and is arranged to reciprocally drive, in synchronism, the reed shaft 21 of the loom and also the rapier drive mechanism 110.

The drive mechanism 100 includes a mechanical linkage (ie an assembly of pivotally joined rigid links) which, in the illustrated embodiment, includes a main drive link 6, a reed link 9, and a rapier link 10. The reed link 9 is connected to the crank arm 20 and the rapier link is connected to the rectilinearly reciprocal drive member 40.

The main link 6 is connected to the side frame 30 of the loom by a first pivot 13 and is connected to the reed link 9 and rapier link 10 by second and third pivots 7 and 8 respectively.

The reed link 9 is connected to the crank arm 20 by a fourth pivot 11 and the rapier link is connected to the drive member 40 by a fifth pivot 12.

The drive link 6 is reciprocally driven about the first pivot 13 by a connecting link 4 which at one end is pivotally attached to the drive link 6 by a pivot 5 and which at its other end is pivotally mounted on a drive wheel 2 by a pivot 3. The drive wheel 2 is mounted on a main drive shaft 1 of the loom and rotates continuously in the direction of arrow D. Pivot 3 is spaced from the axis of rotation of the shaft 1 by a predetermined distance and acts as a crank to reciprocally drive the connecting link 4.

Accordingly one complete rotation of the wheel 2 causes the link 6 to be pivotally moved on an upward stroke ie from its lower limit of reciprocal motion (this lower limit is shown in Figure 1) to its upper limit of reciprocal motion (this upper limit is shown in Figure 3) and then on a downward stroke ie from its upper limit back to its lower limit.

On each of the upward and downward stroke of the drive link 6 the reed link 9 and rapier link 10 are each caused to move about their respective pivots 7,8 and so cause the fourth and fifth pivots 11 and 12 to move along respective arcuate paths of movement; this results in a change in the spacing between each of these pivots and the first pivot 13 and so provides synchronised displacements of the fourth and fifth pivots for reciprocally driving the reed shaft 21 and rapier drive mechanism 110 respectively.

It will be noted that when the link is at its upper limit (Figure 3), the mechanism 100 is arranged such that the reed 24 is at its beat-up position. In this position it will also be noted that the reed link 9 is substantially perpendicular to the drive link 6 whereas rapier link 10 is generally longitudinally aligned with link 6. This arrangement is chosen in order to cause, in this vicinity of angular movement of link 6, a displacement of the reed controlling fourth pivot 11 which is greater than the displacement of rapier controlling fifth pivot 12 (this enables displacement of the reed 24 without significant movement of the rapier for the beat-up cycle of the loom). This enables the beat-up cycle of the loom to be undertaken with the rapier parked' to one side the warp sheet whilst the reed 24 undergoes its beat-up sequence. In terms of rotation of the drive wheel 2, this sequence occurs over an angular displacement of the wheel of about 120 degrees.

As can be seen from Figure 2 and 3, a reverse situation arises when the drive link 6 moves in the region towards the end of its lower stroke and the first part of its upper stroke. In this vicinity of movement, the reed link 9 reciprocally moves from one side of link 6 to the other throughout a range of movement where it is substantially aligned with link 6; according in this range of movement of link 6, the reed 24 is moved backwards and forwards relative to the fabric 50 at a sufficient distance to allow insertion and retraction of the rapier for weft insertion into the shed S. During this same range of movement of the link 6, it will be noted that the rapier link 10 is substantially perpendicular to link 6. Accordingly in this range of movement of the link 6, the rapier controlling fifth pivot 12 undergoes a greater displacement (which causes rapier insertion/retraction) than the displacement of the reed controlling fourth pivot 11. In terms of rotation of the wheel 2, the rapier insertion/retraction sequence occurs over about an angular displacement of about 220 degrees.

In the above example it is envisaged that each of the first to fifth pivots may be formed by suitable roller or ball bearings.

It is envisaged that the effective lengths of links 6,9 and/or 10 may be adjustable to provide adjustment of the displacement of the reed controlling fourth pivot 11 and/or the displacement of the rapier controlling fifth pivot 12.

Claims

CLAIMS1. A drive mechanism for a rapier and beat-up reed of a rapier loom, the drive mechanism being defined by a mechanical linkage which is adapted to be reciprocally driven by a drive shaft of the loom, the mechanical linkage including first and second reciprocally driven outputs, the first output being adapted to be connected to the reed of the loom to drive the reed between reed beat-up and reed retracted positions and the second output being adapted to be connected to the rapier of the loom so as to reciprocate, in synchronism with the reciprocal movement of the reed, the rapier between a rapier inserted position and a rapier retracted position.
2. A drive mechanism according to claim 1 wherein the mechanical linkage includes a main drive link which is reciprocally driven about a first pivot between a first limit of reciprocal movement and a second limit of reciprocal movement, a reed link pivotally connected at one end by a second pivot to the main drive link so as to be reciprocally driven thereby between a reed beat-up position and a reed retracted position and a rapier link pivotally connected at one end by a third pivot to the main drive link so as to be reciprocally driven thereby, in synchronism with the reed link, between a rapier inserted position and a rapier retracted position.
3. A drive mechanism according to claim 2 wherein the reed is mounted on a reed shaft rotatably mounted in the loom frame, the first output of the mechanical linkage being defined by a crank arm adapted for connection to said reed shaft, the crank arm being pivotally connected to said reed link by a fourth pivot to cause reciprocal movement of the crank arm on reciprocal displacement of the reed link.
4. A drive mechanism according to claim 3 wherein the second output of the mechanical linkage is defined by a linearly reciprocally displaceable drive member adapted for connection to the rapier drive mechanism of the loom, the rapier link being connected by a fifth pivot to said drive member to cause linear reciprocal displacement of the drive member on reciprocal displacement of the rapier link.
5. A drive mechanism according to claim 4 wherein said pivots are arranged such that on reciprocal movement of the main link about the first pivot, when the distance between the first and fourth pivots tends to increase the distance between the first and fifth pivots tends to decrease, and vice versa.I
6. A drive mechanism for a rapier loom substantially ass herein described with reference to and as illustrated in the accompanying drawings.
7. A rapier loom including a drive mechanism according to any preceding claim.