GB2437959A

GB2437959A - Indirect jaquard warp control

Info

Publication number: GB2437959A
Application number: GB0609294A
Authority: GB
Inventors: John Rush
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-05-11
Filing date: 2006-05-11
Publication date: 2007-11-14
Also published as: GB0609294D0

Abstract

The system of a jacquard and harness is a known and reliable method of converting pattern information into warp position for jacquard weaving. However, the generation and transmission of the full shedding amplitude to the loom causes problems with the harness and increases the size and power requirements of the jacquard. An alternative system is to use the jacquard and harness to transmit only the pattern information to the loom in the form of a small displacement, and use a mechanism on the loom which provides mechanical drive for the shed amplitude, and which can be controlled by the small displacement.

Description

I

INDIRECT JACQUARD WARP CONTROL

This invention relates to the control of the shed position of warp threads on a loom with ajacquard connected to the loom via a harness, in which the jacquard and harness produce and transmit the pattern information in mechanical form, which information is then translated into actual warp position by devices on the loom.

It is well known that a jacquard machine can be used to produce direct control of individual warp position via a harness and heddles. However in this conventional form, the jacquard must produce the full shed amplitude required and the harness must transmit this full shed amplitude to the loom. With increasing loom speeds this creates increasing problems in terms of the heat generated in the jacquard and wear on the harness. The jacquard and harness arrangement is however a well known and reliable technology for transforming the usually electronic pattern information into mechanical motion and for transmitting that information to the loom, An alternative system therefore is to provide on the loom a mechanical means capable of moving warp threads through the shedding amplitude required, and to control the influence of such means on the warp with a small amplitude mechanical motion signal from the jacquard and harness. The reduction in amplitude of motion required of the jacquard and harness will very greatly reduce the problems currently associated with these components.

Figure 1 shows a view of an assembly capable of controlling the shedding position of a warp thread from a small mechanical input signal.

Figure 2 shows the assembly of figure 1 connected via a harness to a jacquard type machine, so that the jacquard controls the warp shedding position.

The arrangement shown in figure 1 consist of three components which operate together to control the warp position. The first component 1 is a flat piece of matenal with a slot 2 in formed in one edge, so that the slot is not closed. l'his component oscillates over slightly more than the full shed amplitude at loom speed, and this may be regarded as equivalent to a conventional heddle except that the heddle slot is open rather than closed. The second component is a catch plate 3, which is placed so that one edge of the catch plate slightly overlaps the slotted edge of the heddle. The overlap between these two components 1 and 3 effectively closes the open slot 2 in the heddle over most of the oscillating range. A warp thread 5 may be passed over the rear of the heddle, through the slot and over the front of the catch plate. Because the slot is effectively closed over most of the range of oscillation, the warp is therefore positioned by the slot 2 in the heddle 1, which is the same situation as with a conventional heddle. The oscillating range of the heddle I extends above the catch 4 fonned in the upper region of the catch plate 3. If the catch is exposed as shown in figure 1 then when the heddle reaches the upper end of oscillation, the warp 5 will leave the slot 2 in the heddle 1 and fall into the catch 4 on the catch plate 3. If nothing else occurs the warp would remain in the catch 4 while the heddle continues to oscillate, so the warp is positioned by the catch. The third component of the assembly is a release plate 6, which is placed next to the catch plate. The release plate has a protrusion 7 near its upper end, which in figure 1 is just below the catch 4. The upper edge of the protrusion is angled towards the heddle. The release plate is mounted in the assembly such that it may be raised sufficiently for the protrusion to cover the catch on the catch plate. In such a case, then when a warp has been retained by the catch and the release plate is raised, the angled upper edge of the protrusion will lift the warp out of the catch and push it towards the heddle. When the beddle next reaches its upper range of oscillation and the slot comes above the catch, the angled upper edge of the protrusion will then force the warp into the slot. As the heddle continues its motion the warp will then be released from the catch plate and move with the slot in the heddle. Thus, a relatively small movement of the release plate determines whether the warp is in the heddle slot or on the catch plate catch. With the appropriate timing the position of the warp at weft insertion may thus be determined by a relatively small movement of the release plate.

In figure 2 the assembly of figure 1 is shown with the release plate 6 connected at its upper end via a harness cord 8 to ajacquard type machine 9. The release plate 6 is in this case in its upper position, so that the catch is covered and a warp would not be retained by the catch plate. The selectors within the jacquard type mechanism may well be of a larger footprint than the warp control assemblies (components 1,3 and 4) on the loom, in which case the harness cord 8 will require guides 10 to located either end of the harness cord. The jacquard type mechanism operates in the normal function of transforming a pattern signal which is likely to be electrical into a vertical mechanical movement of the harness cord, with a position determined for each pick.

However, since it is connected to the loom warp control assembly, this movement is of less amplitude than the shedding amplitude on the loom. For example, with the mechanism shown in figure 1, the movement needed to cover or uncover the catch 4 will be of the order of 8 to 10 mm. Thus only this small displacement needs to be produced by the jacquard and transmitted through the harness, with a consequent substantial reduction in problems associated with these components. The release plate may conveniently be lifted by the harness to its upper position, and returned to its lower position by a tension spring 11 attached to its lower end.

The concept embodied in the loom components shown in figure 1 is not unique. It is possible to design other systems which operate differently, but which will give the same result. Such systems may for example have more than one component which oscillates continuously to provide the motional drive for a warp thread. There would then be another component which controls the influence of these continuously oscillating components on the warp, according to the position of this other component. This position is then derived from a source which transforms the pattern information into a mechanical pattern signal which is smaller in amplitude than the shedding amplitude. When the signal is a simple linear displacement it can be easily effected on the loom by the combination of a modified jacquard and harness.

Claims

CLAIMS

1 A shedding system for jacquard weaving which has a jacquard type mechanism capable of producing a mechanical displacement of one or more ends according to pattern information, where said displacement is smaller in amplitude than the shedding requirement of the loom, and in which said displacement is transmitted to said loom via a harness, and in which said displacement transmitted to said loom via said harness operates to change the position of one or more control components, and in which said control component or components control the influence of one or more continuously oscillating components on a warp thread.

2 A shedding mechanism as in claim I in which there is one continuously oscillating component, and in which there is one control component connected to the jacquard type mechanism via a harness, which may be displaced across the warp direction, and in which the position of said control component determines whether or not the warp thread is inserted into said oscillating component or withdrawn from said oscillating component and retained by a third component.