DIRECT WARP SELECTION DEVICE

BACKGROUND

For cloth, which is to be woven with a regular pattern, the warp may be controlled by heddles, which are fixed in frames. The heddle frames move in a regular pattern, which moves the warp threads in a regular pattern, and so produces cloth with a regularly repeated weave. For cloth in which the pattern is irregular, the warp

5 threads may still be controlled by heddles, but each individual heddle requires individual control. At present this is usually done with a Jacquard machine, which is able to lift or lower individual heddles according to an external signal. However, the actuators for the Jacquard are too large to install directly on the loom, and they are therefore connected to the individual heddles with cord, the collection of cords

10 being called a harness. With increasing loom speeds the harness presents increasing problems, and it would be better to be able to install a warp thread control mechanism directly on the loom.

STATEMENT OF INVENTION

The present invention is a mechanism that can be installed directly on the loom, for the control of the shedding of individual warp threads. Each mechanism consist of a

15 heddle and other components which operate in conjunction with it, the collection of components including the heddle being called a selector. The heddle is of a special type in which the slot, which accommodates the warp thread, is not closed. The heddle oscillates regularly over the amplitude of the shed. The warp thread may be retained in the heddle and oscillate with it, or may be removed from the heddle and 0 retained at top or bottom shed, and may be reinserted into the heddle. hi these embodiments of the invention, the removal, retention and re-insertion of the warp takes place only at one side of the shed, either top shed or bottom shed. The speed of oscillation of the heddle is therefore the loom speed, that is, the heddle makes one complete oscillation for each weft insertion. Each selector requires a 5 mechanical drive from the loom for the oscillating motion of the heddle, and a small mechanical motion from an actuator. The actuator transforms the controlling signal for the weaving pattern into the mechanical motion required by the

selector, which changes the effect of the selector on the warp thread. The actuator is not part of this invention.

INTRODUCTION TO DRAWINGS

Figure 1 shows the location of a selector in relation to the other standard components of a normal weaving loom. 5 Figure 2 shows the basic outline of the heddle including the open slot, which drives the warp thread.

Figure 3 shows an embodiment of a warp control rod, which works in conjunction with the heddle in one embodiment of this invention.

Figure 4 shows a further embodiment of a warp control rod. 10 Figures 5 A and B show the relative position of the heddle and warp control rod in a selector as an embodiment of this invention, including the path of the warp thread at approximate mid shed position.

Figure 6 shows a side view of the first embodiment of this invention, with the heddle at its uppermost position, and the consequent position of the warp thread. 15 Figure 7 shows a subsequent condition of this embodiment to figure 6 whereby the warp thread is retained at top shed.

Figures 8A and B show the same embodiment of the invention with the warp thread retained at top shed and the warp control rod positioned so as to subsequently re-insert the warp thread into the heddle. 0 Figure 9 shows a side view of the outline of a catch plate, which is a component in a second embodiment of this invention.

Figure 10 shows a side view of the outline of a release plate, which is a component in a second embodiment of this invention.

Figure 11 shows a side view of an embodiment of this invention, which includes a 5 heddle, a catch plate and a release plate, and indicates the position of the warp thread in the selector.

Figure 12 shows a plan view of the embodiment shown in figure 11, and includes the path of the warp thread through the selector.

Figure 13 shows a side view of the second embodiment of the invention with the 0 heddle proximal to its extreme uppermost position, and the transfer of the warp

thread onto the catch plate.

Figure 14 shows a side view of the second embodiment of the invention, with the warp retained at top shed and the release plate positioned so as to re-insert the warp into the heddle. 5 Figure 15 shows a diagrammatic side view of a weaving loom with three shed positions.

Figure 16 shows an embodiment of a heddle which would be used for a selector on a loom with three shed positions.

Figure 17 shows a side view of a selector for three shed positions, when the retained 10 warp shed position is a bottom shed, and in which the heddle is close to its lowest extreme of oscillation.

Figure 18 shows a side view of a selector as in figure 17, in which the heddle has moved away from its lowest extreme position towards centre shed, and in which the warp is retained in the hook. 15 Figure 19 shows a side view of a selector as in figure 17 but subsequent to figure 18, in which the heddle has moved further, and in which the release plate covers the hook, and the warp is inserted into the second slot in the heddle.

DESCRIPTION

In all of the embodiments the selector is mounted in the loom in the position shown in figure 1. For a normal loom, which weaves horizontally, the selectors 1 for the

20 warp threads will be approximately vertical. The selectors 1 are installed in the path of the warp threads to the immediate rear of the weft insertion region, since it is the selectors which produce the desired shed pattern. The warp is supplied for example by a beam 10, and is fed through to the fell point 13 and cloth take up 14. The lines 11 and 12 indicate the upper and lower shed positions for the warp for a selector in 5 the position shown. A mechanical drive 2 for the oscillating heddles may be provided at one or at both ends of the selectors. The actuators 3 which transform the pattern signal into a mechanical motion, are shown provided at one end of the selectors. In the first embodiment of this invention there is a heddle of the type shown in figure 2. The heddle 4 is a long flat bar of approximately rectangular cross section, the 0 thickness of the bar perpendicular to the side view shown in figure 2 being

approximately uniform. The central part of the heddle has an open slot 5 in one side, which is large enough to accommodate a warp thread. The enlarged view of the slot shows that it may have inner perpendicular surfaces 6 to assist in driving the warp thread, and outer angled surfaces 7 to assist in the removal and insertion of the warp thread. For a selector which may retain the warp at top shed for example, the angled surfaces 7 can be present only on the lower side of the slot 5 to assist in warp removal from the slot 5, the opposite perpendicular surface 6 being extended to the edge of the heddle. The heddle is driven in a uniform cyclic motion over an amplitude slightly greater than the shed height at the selector position. In order that this can occur, the heddle has extensions 8 and 9 on its upper and lower ends, to facilitate connection and drive. These extensions may be separately fabricated and attached, or may be part of a single fabrication. The extension pieces 8 and 9 are dimensioned for this requirement and so as not to interfere with the warp selection process. In this first embodiment of the invention, the heddle 4 operates in conjunction with at least a second component, the warp control rod 15, which may be as shown in figure 3. This is a rod or tube of circular cross section, which has a hook 16 as shown. The hook 16 is sufficiently large to accommodate a warp thread. The warp control rod 15 is located in the loom such that when the hook 16 retains the warp thread, the warp thread will be at position 11 or 12 in figure 1. There is a smooth surface in the transition from the surface of the rod to the hook. The warp control rod 15 could be fabricated as shown in figure 4, in which the hook 16 is cut into the body of the rod, rather than protruding from the surface as shown in figure 3. The warp control rod is required to undergo axial rotations through a segment of a circle, according to the influence of the actuator that translates the pattern signal into mechanical motion. The warp control rod is therefore extended as required and will have guides as required to facilitate this.

For the assembly of a selector the heddle 4 and the warp control rod 15 are placed in the loom proximal to each other as shown in the side view of figure 5 A and the plan view of figure 5B. The warp control rod in figure 5 A and B is of the type shown in figure 3, for clarity only. The front of the loom at which the weft insertion occurs, may be to the left or right of the assembly shown. Figures 5A and B show a single

warp thread 17 in place in the selector. The warp thread will be under some tension. The relative position of the heddle and warp control rod is such that when the warp thread is under tension it will be in contact with one side of the heddle 4, and passing through the selector, will be in contact with the opposite side of the warp control rod 15, as shown.

The operation of this embodiment of the invention is a follows. Figure 5 A shows the heddle 4 when it is not at the upper or lower shed positions, and the warp is in the slot 5 in the heddle. For this condition the warp is retained in the slot 5 because of the tension in the warp, and the relative position of the heddle 4 and the warp control rod 15. The path through the slot 5 is the shortest path. The warp thread will therefore move with the heddle as the heddle oscillates. The warp control rod may be turned such that the hook 16 is facing sideways. The heddle moves toward one end of the shed, for example top shed, and overshoots the hook slightly, sufficient to drive the warp thread above the hook 16 on the warp control rod, as shown in figure 6. The geometry of the system, for example the degree of overshoot and the size of the slot 5, is sufficient to ensure that the warp thread 17 overshoots the hook 16. The heddle will continue to oscillate, but in moving away from its extreme position, will leave the warp thread 17 in the hook 16 on the warp control rod 15, as shown in figure 7. The warp is therefore retained at this position, for example top shed, as the heddle continues to oscillate. The warp will connect with the heddle with each cycle of oscillation, but will be retained by the hook. It is clearly necessary to be able to reinsert the warp into the heddle. To do this the warp control rod 15 may be rotated as shown in figures 8 A and 8B in plan view. The hook 16 is in this figure facing away from the heddle. As the heddle moves to the position of the warp 17 the warp will drop into the slot 5 on the heddle 4, and the warp will move with the heddle over the last extreme portion of the heddle oscillation. This would remove the warp 17 from the hook 16, but with the hook positioned as shown, the warp will then spring clear of the hook. Thus, as the heddle stops and returns, the warp is then not caught by the hook, but continues to move with the heddle. So long as the hook 16 is not within the direct path of the warp thread, it will not catch the warp thread, which will therefore oscillate with the heddle. It is thus possible to use the selector as shown to control the position of a warp thread for weaving. The timing of the process can be

such that when weft insertion occurs, either the warp is at bottom shed if it is being driven by the heddle, or it is retained at top shed on the hook 16. The timing of the selection process from heddle to hook, or de-selection from hook to heddle, can be varied. For example, for selection from heddle to hook, the hook may face away from the heddle until the heddle is proximal to its extreme position, so that the warp does not have to be driven over a protruding hook as shown in figure 6. The warp control rod may then be rotated through 90 degrees to face sideways as figure 6 so that the warp is selected on the return path of the warp and heddle. Further, to de-select the warp from the hook to the heddle, the hook may face sideways as figure 6 until the heddle and warp are proximal to the extreme position, and the warp is above the hook, at which time the warp control rod is rotated to face away from the heddle. With these timing options, it is possible to operate the selector such that when the hook should not catch the warp, that is, to not-select or to de-select the warp, the hook is rotated to face approximately towards the heddle, but such that the hook is not directly in the path of the warp.

A second embodiment of this invention is possible, in which the heddle with an open slot operates with two other components to make the assembly which is the selector. One of these two other components is a catch plate 18 as shown in figure 9 in side view. The catch plate 18 is rectangular in cross section and would be of similar dimensions to the heddle as shown in figure 2. A hook 19 is formed in its length, the hook 19 being large enough to accommodate a warp thread. The two ends of the catch plate 18 are extended as necessary to fix it in the loom in the correct position, and additionally to maintain the part under some tension to facilitate accuracy if necessary. The extended ends of the catch plate are not directly involved in warp selection. The central section of the catch plate can be a uniform cross section as shown. The catch plate is fixed in the loom such that if a warp thread were held in the hook 19, the warp would be at the correct upper (as shown) or lower shed position for that selector in the loom. The other component, which operates with a heddle to produce a selector, is a release plate 20, as shown in figure 10. This is again a bar of material of rectangular cross section, and of similar dimensions to the heddle and catch plate. The release plate 20 may have a uniform cross section over the majority of its length, but has over part of the length, a protrusion 21 as shown.

The extent to which the protrusion 21 protrudes from the release plate 20 is comparable with the depth of the hook 19 in a horizontal direction from the edge of the catch plate. The release plate has upper and lower extensions similar to the other two components in the selector, which enable it to be positioned and guided in the selector. The release plate is capable of vertical displacements, of a magnitude of approximately twice the height of the hook 19, from the outer acute corner to the nearest inner corner, in a vertical direction. The release plate is connected mechanically to the selector actuator mechanism, which provides these vertical displacements, according to whether the warp thread should be retained by the catch plate or not retained.

To produce a selector of this second embodiment of the invention, a heddle 4, catch plate 18 and a release plate 20 are relatively located according to figures 11 and 12. For clarity of description it is assumed that for these two diagrams, the heddle is in the rear of the selector in the loom. The heddle is shown on one side of the selector assembly. For a vertical heddle, the catch plate 18 is displaced from the heddle 4 in both horizontal directions, so that it is to one side of the heddle and for example in front of the heddle. To ensure that the catch plate is at the side of the heddle, the front edge of the heddle 4 may overlap the rear edge of the catch plate 18 as shown in figure 12. The release plate 20 is mounted next to the catch plate, so that overall, the catch plate is in the middle and the heddle 4 and release plate 20 are the two outer components. The release plate 20 is positioned such that the rear vertical edge of the protrusion 21 extends beyond the rear vertical edge of the catch plate in the vicinity of the hook 19. The release plate 20 is shown in figure 11 in a position whereby a warp thread would be retained by the catch plate. The operation of the selector may be explained with reference to these and subsequent figures. In figure 11 the selector is shown with the heddle at approximately mid shed position and a warp thread 17 in place, passing through the open slot in the heddle. Figure 12 in plan view shows that the warp thread 17 passes over the outer side of the heddle 4, and thence through the open slot, hi both figures 11 and 12 it can be seen that the warp thread then passes the rear edge of the catch plate and then over the outer side of the release plate 20. With the catch plate shaped as shown, and overlapping the front edge of the heddle, it can be seen that the open

slot in the heddle is effectively closed in this position by the rear edge of the catch plate. The warp thread 17 cannot therefore leave the slot over the centre shed range, and the slot is effectively closed as in a conventional heddle with a closed eye. The heddle 4 is made to oscillate over a range slightly greater than the shed height for the selector position. For a selector with a hook at top shed, the heddle will oscillate such that the open slot 5 travels beyond the lowest opening of the hook in the catch plate. This position is shown in figure 13. It can be seen that the warp thread is transferred to the hook 19 in the catch plate. This will occur because of the tension in the warp and the relative positions of the heddle and catch plate, and the fact that in this position of the heddle, the slot 5 is open. When the heddle then subsequently moves away from this extreme position towards centre shed, the warp thread will be retained by the hook 19 in the catch plate, at top shed. Subsequent oscillations of the heddle will not release the warp from this position. The warp thread may be released from the catch plate by raising the release plate 20 as shown in figure 14. The extent of the vertical displacement of the release plate 20 is such that the warp thread is removed from the hook, and the protrusion 21 of the release plate 20 covers the point of the hook 19. The displacement must occur before the open slot in the heddle leaves the hook region in a downward motion. The displacement can occur as shown in figure 14 during the upward motion of the heddle if the upper edge of the protrusion 21 is correctly angled. In this case, the warp will be removed from the hook but will remain at top shed rather than dropping towards centre shed. When the released plate is in a raised position and the heddle traverses the upper segment of its range past the hook, the warp will transfer into the open slot 5 because of the warp tension. As the heddle then moves down towards centre shed, the hook is covered by the release plate protrusion 21, and the warp will not be retained but will again move with the open slot in the heddle. The open slot is again closed as soon as the slot leaves the hook region, and the release plate 20 can be returned to its lower position. It can be understood that if the warp is in the heddle slot, and the release plate 20 is in the raised position as the heddle reaches top shed, then the warp will not be transferred to the catch plate hook 19, but will remain in the heddle. The selector is therefore capable of positioning a warp thread for weft insertion, either at top or bottom shed in the catch plate, or in the heddle which may be at bottom or top shed

when weft insertion occurs. The only determining factor is the displacement of the release plate 20, which is a relatively small motion. It should be noted that it is the relative position of the catch plate and the release plate, which determines whether or not the warp is retained by the hook. It is therefore equally possible to keep the release plate stationary and impose the selection motion on the catch plate, hi this case, the catch plate is raised to remove or retain the warp, and lowered to release it back into the heddle.

It is possible in some types of weaving operation that a three or more position shed is needed, for example hi carpet weaving. A further embodiment of the invention enables this to be done, and it will be understood that the same mode of operation would apply to a shedding arrangement with more than three shed positions. The geometry for three positions of the warp is illustrated in figure 15. This shows possible warp positions at weft insertion. The line 12 is the bottom position, line 25 is the mid shed position and line 11 the top position. The weft or other things may be inserted across the warp; hi front of the selectors 1 either between warps at 12 and 25 or between warps at 25 and 11.

For a three position shed the heddle 22 is modified to have two open slots 23 and 24 as shown hi figure 16. These slots 23 and 24 are similar to the slot 5 shown hi the heddle in figure 2. The heddle 22 is otherwise similar to that shown in figure 2, but may be extended lengthwise to allow for the increased vertical oscillation which may be necessary in this embodiment. To produce a selector, the heddle 22 is combined with a catch plate 18 and a release plate 20, again similar to those shown hi figures 9 and 10. These components may also be extended lengthways. The arrangement of the components 22, 18 and 20 hi plan view is the same as that shown in figure 12, except that the heddle is now 22 and not 4. hi figure 17 an inverted arrangement is shown, with the hook 19 on the catch plate facing downwards rather than upwards, hi this case, the hook would be positioned so that the warp retained by the hook is along line 12 in figure 15. Figure 17 shows a warp thread passing correctly through the selector, and retained by the hook 19 on the catch plate 18. It can be seen that the release plate is positioned so as to expose the hook to the warp.

The heddle 22 oscillates regularly at loom speed as in the previous embodiments. The magnitude of the oscillation is such that the upper slot 23 hi figure 16 will move

from below the hook 19 on the catch plate 18 to at least the upper shed position indicated by line 11 in figure 15. In figure 17 the heddle is positioned so that the top open slot 23 is below the hook 19 and warp thread 17. This would be proximal to the lowest point of travel of the heddle. Figure 18 shows a subsequent side view of the same selector as in figure 17, with the heddle now moved towards centre shed. The release plate 20 has not been moved and the hook 19 is still exposed to the warp. The warp thread will therefore remain in the hook 19 on the catch plate, and will not be inserted into the slot 23. Subsequently the heddle moves further as shown in figure 19. Between the passing of slot 23 and the passing of slot 24 relative to the hook, the release plate is moved down to cover the hook 19. This will force the warp thread 17 into the open slot 24 as it passes the hook. Again subsequently to this the heddle will continue to move up, until in this case, at the heddles uppermost position, the warp thread will be at the middle shed position. The position of the slots 23 and 24 in the heddle is such that, when the lower slot 24 is in the desired middle shed position, the upper slot 23 is at the upper most shed position. It can be understood that if the release plate is moved early rather than late, the warp thread could be inserted into the upper slot 23. hi this case, the warp thread would be carried to the upper shed position rather than the middle shed position. Since the heddle oscillates at loom speed, that is one cycle for each weft insertion, the warp will be brought back to the lowest position after each insertion. Before the next weft insertion it can again be positioned by the selector. If the release plate is not moved down to cover the hook 19 during selection, the warp will be retained by the hook 19 at bottom shed when weft insertion occurs.