WO1987007919A1

WO1987007919A1 - Device for carrying heddle or reed cords in a loom

Info

Publication number: WO1987007919A1
Application number: PCT/SE1987/000274
Authority: WO
Inventors: Thord SUNDSTRÖM
Original assignee: Sundstroem Thord
Priority date: 1986-06-18
Filing date: 1987-06-10
Publication date: 1987-12-30
Also published as: SE453671B; EP0269722A1; DK80888D0; SE8602707D0; DK80888A; FI880733A; SE8602707L; FI880733A0

Abstract

A device for carrying heddle or reed cords (17) in a loom with parallel warp threads (1) stretched in a plane, has two lays (10) located opposite to each other extending above the warp threads parallely to and on both sides of said plane and between which go the heddle or reed cords. Both lays (10) are synchronously rotatable about an axis of rotation (2) for adjusting the angle (alpha) between the lays (10) and the warp threads (1). Each lay (10) has a rotation means (13, 14), which is arranged to give the lay a simultaneous rotation movement about its own longitudinal axis (L) when the lay is rotated about said axis of rotation. Each lay (10) carries a yarn trapper (16) for each heddle of reed cord (17) and has a helix-formed groove for each trapper, which has an increasing pitch in direction from said axis of rotation and in which the trapper (16) is arranged to run in order to be displaced along the lay (10) when this is rotated. The increasing pitch of the grooves is so chosen relative to the exchanging between turning of the lay (10) and, caused by it, the rotation of the lay, that the position of each trapper (16) perpendicular to the warp threads (1) in said plane is essentially constant independent of the position of rotation of the lay (10) relative to the warp threads (1).

Description

Device for carrying heddle or reed cords in a loom

The present invention relates to a device for carrying heddle or reed cords in a loom with parallel warp threads stretched in a plane, which device has two lays located opposite to each other extending above the warp threads parallelly to and on both sides of said plane and between which go the heddle or reed cords.

In conventional looms fabrics are produced in which the warp threads and the weft threads form right angles with each other. Certain older types of looms for producing fabrics in which the warp threads and the weft threads form an angle other than 90 , (usually 45 ) with each other are known, e.g. through the American patent specifications 811 597, 1 141 635 and 1 280461. In these patent specifications, looms for producing fabrics are shown in which the angle between the warp threads and the weft threads is 4 455 .. FFaabbrriiccss iinn wwhhiicchh tthhee aannggllie is other than 45 , cannot be produced in these known looms.

When producing fabrics from e.g. glass fibres or carbon fibres, which will be parts of a composite material, which e.g. will be used in aircraft industry for manufacturing of wing- or fuselage parts, it is often desirable to give the fabrics a raised break- ing stress in different directions. A raised breaking stress in optional direction in a fabric could be achieved if the fabric could be woven with an angle, dependent on this direction, between the warp threads and the weft threads.

Therefore there is a need for a loom in which this angle can be adjusted in a simple way, i.e. a loom in which the plane of the heddle cords as well as the plane of the reed threads can be inclined at an arbitrary angle relative to the warp threads.

The object of the present invention is therefore to achieve a device for carrying heddle or reed cords in a loom, which device makes possible an arbitrary adjustment of the angle be- tween the heddle-cord plane or the reed-cord plane and the warp threads.

This object is achieved according to the present invention by a device which is of a kind mentioned introductorily and which is characterized in that both lays are synchronously rotatable about an axis of rotation located at one end of the lays and per¬ pendicular to said plane for adjusting the angle between the lays and the warp threads; that each lay has a rotation means which is arranged to give the lay a simultaneous rotation move- ment about its own longitudinal axis when the lay is rotated about said axis; that each lay carries a yarn trapper for each heddle or reed cord and has a helix-formed groove for each trapper which has an increasing pitch in direction from said axis of rotation and in which the trapper. is arranged to run in order to be displaced along the lay when this rotates about its own longitudinal axis, whereupon the increasing pitch of the grooves is so chosen relative to the exchanging between the rota¬ tion of the lay about said axis of rotation and, caused by it, the rotation of the lay about its own longitudinal axis, that the position of each trapper perpendicular to the warp threads in said plane is essentially constant independent of the rotation position of the lay relative to the warp threads.

In a preferred embodiment, each lay consists of a screw, which is mounted rotatably about its own longitudinal axis in a tubular, as to rotation about its own longitudinal axis fixed casing, which has a longitudinal slot; the grooves for the yarn trappers are formed by threads of screw, in which the trappers are located; and the trappers have a part, protruding through the slot of the casing, for holding the heddle or reed cords.

The invention will now be more particularly described with refer¬ ence to the attached drawings.

Fig. 1 is a diagrammatical view and shows the problem which is solved by the present invention.

Fig. 2 is a perspective view and shows an isolated part of a device according to the present invention, partly in section.

Fig. 3 is a diagrammatical view corresponding to fig. 1, and shows a part of a screw that is part of the device.

Fig 4 shows helix-formed grooves in the screw.

Fig. 5 shows a yarn trapper.

The parallel straight lines 1 in fig. 1 represent a few of several parallel warp threads, which are stretched in a plane in a loom. A lay, rotatable about an axis 2 that extends at right angles to the plane of the warp threads, and which lay extends over the warp threads is represented in fig. 1 by its centre line, and is shown with the line 3 in a position perpendicular to the warp threads and with the line 3' in a rotating position where the centre line form an angle with the warp threads. The inter- sectional points between the line 3 as well as the line 3' and the lines 1 are marked with crosses that represent the positions of the heddle cords carried by the lay in the respective lay positions. If the lay carried reed cords instead of heddle cords, the positions of these would be represented by markings located between the drawn crosses in fig. 1, i.e. between the warp threads. The reasoning below concerns however heddle cords as well as reed cords, i. e. irrespective of whether the mark¬ ings are placed on the intersectional points or between these. The distance between the axis 2 and the first cross (the heddle cord closest to the axis 2) is a., the distance between the axis 2 and the other cross (the next heddle cord) is a„ and so on.

It is evident from fig. 1 that when rotating the lay from the 90 -position shown (line 3) to the rotating position shown (line 3'), each heddle cord (cross) must be displaced continually along the lay, always to be just in front of the respective warp thread. This displacement is in fig. 1 designated x₁ for the heddle cord located closest to the axis 2, _? for the next heddle cord, and so on. As is clearly evident from fig. 1, said displace- ment increases with the distance from the axis 2. The displace¬ ment x. is given generally by x. = a. ( —: 1) l ^{} }} l l sinα i = 1, 2, 3 ... . This condition must then be at least approxi¬ mately fulfilled to make it possible to achieve an arbitrary angle α between lay and warp threads and, by that, between weft threads and warp threads.

The device partially shown in fig. 2 has a horisontal upper lay and a horisontal lower lay, which are located right above each other and each of which consists of a screw 10, which is mounted rotatably about its longitudinal axis L in a tubular cylinder 11. Lays are arranged on both sides of the plane in which the warp threads 1 are stretched parallelly in a loom.

Both screws 10 have at their left ends pivots 12, which are firm¬ ly fixed to the screws, respectively. Both pivots 12 are at their left ends (not shown in fig. 2) mounted in a slide valve element each, which is elevatingly mounted in the left part of the side frame of the loom. Each pivot 12 is rotatably mounted about its longitudinal axis converging with the longitudinal axis L of the screw 10 in its slide valve element. Each pivot 12 is also so mounted in its slide valve element, that it is rotatable about a vertical axis of rotation (which corresponds to the axis 2 in fig. 1).

Both cylinders 11 are at their right ends (not shown in fig. 2) attached to a slide valve element each, which is synchronous to the slide valve elements in the left part of the side frame elevatingly mounted in the right part of the side frame of the loom.

The right part of the side frame is displaceable along a groove located in a horisontal plane, which has the form of an arc whose centre is located on the vertical axis of rotation. When moving the right part of the side frame along the groove, the cylinders 11, and thereby the screws 10, are thus rotated about the vertical axis of rotation.

Each pivot 12 carries a bevel gear wheel 13 firmly fixed to it, which mesh with an arc-formed toothed segment 14, which is firmly fixed to the respective slide valve element, and whose centre is located on the vertical axis of rotation. As the right part of the side frame is displaced along its groove and both cylinders 11 and the screws 10 are consequently rotated about the vertical axis of rotation, the gear wheel 13 and the toothed segment 14 achieve a simultaneous rotation of the respective screw 10 in its cylinder 11. In a preferred embodiment both screw-cylinder parts 10-11 are rotatable 45 between a position corresponding to α = 90 and a position corresponding to α = 45 (α as defined in fig 1). Hereby the gear ratio of the gear wheel 13 and the toothed segments 14 are suitably such that a rotation of the respective screws 10 about the vertical axis achieves three revo¬ lutions of the screw about its longitudinal axis L.

Each cylinder 11 has a longitudinal slot 15 which for the upper cylinder is turned downwards and for the lower cylinder is turned upwards, as is shown in. fig 2.

In fig 5 is shown a yarn trapper 16 for holding heddle cords 17 or reed cords. The heddle cords 17 in the shown embodiment con- sist of metal wires bent at the ends, and have in their centre part a heddle eye 18. Through each heddle eye 18 of the heddle cord 17 extends a warp thread 1, as is shown in fig. 2, where only a few of the heddle cords 17 and the warp threads 1 are shown. It should also be mentioned here, that the device shown in fig. 2 is intended only for every other warp thread and that a similar device, intended for the rest of the warp threads, is also arranged in the loom. A device, which differs from the one shown in fig 2 only in that the heddle cords 17 have been re- placed by reed cords which are located between the warp threads 1 , is also arranged in the loom. The reed cords are made in essen¬ tially the same manner as the heddle^' cords 17 but have naturally no eye. The reed cords together form a reed for weaving the weft threads.

The yarn trapper 16 shown in fig 5 has an arc-formed part 19 with a T-formed cross section and radially protruding from this a part 20 with a boring 21 through it for hitching a bent end of a heddle cord (or reed cord).

Each s,crew 10 has for each of its trappers 16 a thread which forms a helix-formed groove with the same cross-section form as the arc-formed part 19 of the yarn trapper. Some of these grooves are shown in fig 2, 3 and 4 with their centre lines. Each yarn trapper 16 is with its arc-formed part 19 so inserted in its groove that the protruding part 20 protrudes out of the slots 15 of the respective cylinders 11 (fig. 2). When the screws 10 ro¬ tate, the yarn trappers 16 are displaced relatively along their slots, which means that they are displaced along the respective slots 15. All grooves start on one and the same straight line alongside the envelope surface of the respective screws 10 and, for the reason that a maximum rotation (45 ) of the screw in the preferred embodiment, as mentioned, achieves three revolutions of the screw about its longitudinal axis L, said grooves have an extension such that the yarn trappers 16 can be displaced relative- ly three revolutions along the respective grooves. Each groove must in practice extend somewhat more than three revolutions for the reason that the arc-formed part 19 of the yarn trappers 16 has a certain extension circumferentially.

In fig. 3, which corresponds to fig. 1, is shown a screw 10 in two different positions of rotation, namely a first position of rotation α = 90 (line 3), which constitutes one end position of the screw, and a second position of rotation α = 45 (line 3"), which constitutes the other end position. The intersectional points between the lines 3 and 3" on the one hand and the warp- thread lines 1 on the other hand are in fig. 3 as well as in fig. 1 marked with crosses. In fig. 3 only four of the helix-formed grooves are shown. The crosses on the line 3 also indicate the starting points Of tll s grorjves (or rather the starting points of the yarn-trapper parts 20 and thereby of the heddle cords), and the crosses on the line 3" also indicate the terminal points of these grooves (or rather the terminal points of the yarn- trapper parts 20 and thereby of the heddle cords). In fig 3 it is illustrated that a rotation of the screw 10 from the starting position α = 90° to the terminal point α = 45° achieves three revolutions of the screw about its longitudinal axis.

In order to enable the yarn trappers 16 and thereby the heddle cords 17 to be displaced in the manner described in connection with fig. 1 and 3, i.e. to enable the parts of the yarn trappers 20 always to be just in front of their warp thread at the rota¬ tion of the screw 10 about the axis 1 (fig. 3), the helix-formed grooves have an increasing pitch in direction from the axis of rotation (com 1) i = 1, 2, 3 .

4, which shows to the right three helix-formed grooves at the end located closest to the axis of rotation and shows tas the left three helix-formed grooves at the opposite end of ttve screw.

For the sake of clearness the grooves are shown on separate screws. As is evident the relative distance between the starting points of the grooves is constant. Furthermore it is evident that the pitch of each groove increases with the distance fτom the axis of rotation.

Claims

1. Device for carrying heddle or reed cords (17) in a loom with parallel warp threads (1) stretched in a plane, which device has two lays (10) located opposite to each other extending above the warp threads parallelly to and on both sides of said plane and between which go the heddle or reed cords, c h a r a c t e r i z e d in that both lays (10) are syn¬ chronously rotatable about an axis of rotation (2) located at one end of the lays and perpendicular to said plane for adjusting the angle ( ) between th^ lays (10) and the warp threads (1); that each lay (10) has a rotation means (13, 14) which is arranged to give the lay a simultaneous rotation about its own longitudinal axis (L) when the lay is rotated about said axis of rotation; that each lay (10) carries a yarn trapper (16) for each heddle or ^"reed cord (17) and has a helix-formed groove for each trapper which has an increasing pitch in direction from said axis of rotation and in which the trapper (16) is arranged to run in order to be displaced along the lay (10) when this rotates about its own longitudi¬ nal axis (L), whereupon the increasing pitch of the groove is so chosen relative to the exchanging between the rotation of the lay (10) about said axis of rotation (2) and, caused by it, the rotation of the lay about its own longitudinal ax,is, that the position of each trapper (16) perpendicular to the warp threads (1) in said plane is essentially constant independent of the position of rotation of the lay (10) relative to the warp threads (1).

2. Device according to claim 1, c h a r a c t e r i z e d in that each lay consists of a screw (10), which is mounted ro¬ tatably about its longitudinal axis (L) in a tubular, as to rotation about its own longitudinal axis fixed casing (11), which has a longitudinal slot (15); the grooves for the yarn trappers (16) are formed by threads of screw, in which the trappers are located; and the trappers (16) have a part (20), protruding through the slot (15) of the casing (11), for holding the heddle or reed cords (17).