Loom or like control

Abstract: In loom control for weaving a preselected pattern design or the like, electronically controlled electric actuators (1,10) are programmed for required operation in accordance with the pattern by a computer, each actuator (1) being connected to a warp thread (W) or to more than one such thread of the shed (S) for positive operation of the threads (W) in effecting required shed formations in weaving the pattern. Flexible connection means (2) between the actuator (1) and an eye member (3) receiving a warp thread (W) may be arranged in an endless manner for positive operation of the eye member (3) in either direction. In the case of a knitting machine each actuator is connected to one or more yarn feeders and/or to the carriage or carriages of the machine for their operation in knitting the preselected pattern.

Description: The present invention relates to a weaving machine, and method of controlling the operation of a weaving machine. JP-A-59-19 2749 describes a weaving machine in which heald frames are driven by way of motors controlled by a computer. The computer has a memory in which selected operating parameters are stored for controlling the movement of the heald frames. It has previously been proposed to provide controlled operation of loom warp thread mails or heald frames by fluid pressure operated piston and cylinder means but which has involved valve mechanism to the latter for such controlled operation. Accordingly the present invention provides a weaving machine having apparatus for controlling the movement of healds (3) for moving yarn (W) to form a fabric of a selected pattern; a plurality of electronically controlled electric actuators (1); each actuator has connection means (2, 2 1 , 8) for connecting it to a respective one of said healds (3); each actuator is independently actuable to move said respective heald in a substantially linear movement between first and second extreme positions; computer means having a memory for storing data representing selected operating parameters for producing a preselected textile pattern; said computer means having data transfer means for inputting said data into said memory; said computer means is operable to control actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said respective heald (3) into a selected one of said first and second extreme positions; said first and second extreme positions are variable in response to said selected operating parameters to produce said preselected textile pattern; said first and second extreme positions being controlled by said computer means in response to stored data representing said selected operating parameters thereby to enable oblique or parabolic shedding during operation; means (6, 7) forming part of a feedback closed loop system in a diagnostic routine for monitoring movement of each said heald (3) between said extreme positions in response to actuation of the associated actuator (1) by said computer means thereby to indicate deviation of said movement from normal operation including incorrect linear movement. The present invention also provides a method of controlling the movement of healds (3) in a weaving machine to form fabric of a selected pattern, the method comprising the steps of: providing a plurality of electronically controlled electric actuators (1) each of which is connected to a respective one of said healds (3) and independently actuable to move said heald in a substantially linear movement between first and second extreme positions; storing data representing selected operating parameters for producing a preselected textile pattern; controlling actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said heald (3) into a selected one of said first and second extreme positions; connecting each said actuator (1) to said respective heald (3) by connection means (2,2 1 ,8), said actuator being operable to move said connection means along its own path in a forward or reverse direction, to move said heald between said first and second positions; controlling locations of said first and second extreme positions in response to said stored data representing selected operating parameters to produce said preselected textile pattern thereby to enable oblique or parabolic shedding during operation; and using a feedback closed loop system in a diagnostic routine to monitor movement of each said heald (3) between said first and second extreme positions in response to actuation of the associated actuator (1) thereby to indicate deviation of said movement from normal operation including incorrect linear movement. Practical applications of the invention are shown in the accompanying diagrammatic drawings, in which: Figures 1 and 2 respectively show two arrangements of loom control operation; Figure 3 shows a detail development; and Figures 4, 5 and 6 each show different shed formations which can be achieved. Like parts are referred to by the same or similar reference numerals or letters throughout the drawings. Referring to Figure 1 and for the operation of each warp thread W of a shed S, an electronically controlled electric linear actuator 1 having positive operation in either direction is connected by a flexible elongate heddle or heald member 2 such as cord, twine, thread (e.g. nylon thread) or the like to the warp thread W by the usual eye 3 through which the warp thread passes. The cord 2 continues downwardly are 2 from the eye 3 and is returned in an endless manner to the actuator 1, the cord 2 being guided by pulleys 4 or other suitable guide means for such arrangement and back and forth operation by the actuator 1. As the actuator 1 is operated in one direction i.e. to the right in the drawing the warp thread W is raised whilst on return operation the warp thread is pulled downwardly by the cord at 2 again with a positive action. For required tensioning of the cord 2, a spring 5 is shown interposed in the cord and is carried by and moves back and forth with the latter. Other suitable tensioning means may be employed such as pre-tensioned cord or a spring loaded jockey wheel or the like. Programmed electronic control and operation of a plurality of actuators 1 and corresponding warp threads W can be effected in any suitable manner and preferably directly such as from a pattern, design or the like by a computer or microprocessor aided image analysis system (not shown) operating in phase with the speed of cyclic operation of the loom or by punched tape or similar programming means or by any suitable computer data storage system. Software and pattern or like selection for such programmed operation is hereinafter referred to. Whereas positive operation of each warp thread W is ensured as a precaution against failure or malfunction each actuator 1 is shown monitored by sensing means 6 which detects any departure of the actuator 1 from full linear operation in either direction. Alternatively, or preferably additionally as shown, further monitoring of the linear movement of the cord 2 is also provided in which the back and forth movement of a member such as a metal tag 27 fixed on the cord 2 is followed by a scanner 7 of sensing means for any departure from correct movement. In the event of an indication of incorrect linear movement or no such movement being given by either or both sensing means 6, 7 the relevant actuator can be replaced e.g., in a readily removable manner whilst the sensing means 6, 7 is or are preferably arranged to stop operation of the loom until the defect is remedied and so prevent or minimise the weaving of faulty cloth. Such feedback may thus form part of a closed loop system in providing a diagnostic routine. Since the effort required to operate the cord 2 and warp thread W is small the actuator 1 can be of low power compact form and likewise the cord 2 and guide pulleys 4, can be compactly arranged. Having regard to the considerable number of warp threads W this enables a corresponding number of actuator/cord arrangements to be closely positioned in relation to the shed 5 especially by orientation about the vertical through an eye connection 3 to a warp thread W. The path of the cord 2 and positioning of the guide pulleys 4 may vary from that shown but the arrangement is preferably such that the linear actuator 1 is disposed in the optimum horizontal position for satisfactory operation. Although the use of a linear actuator 1 is preferred, linear actuation may be obtained from a rotary motor such as a stepping motor or servomotor driving a crank arm for back and forth movement, the free end of which is anchored to the cord 2 and is reciprocated by the motor through an arc which has the effect of imparting required linear movement to the cord. In the case of a reversible stepping motor or other suitable motor it may drive a drum or similar member about which the cord 2 is wound in a capstan fashion, the forward and reverse drive of the drum imparting back and forth linear movement to the cord 2. If desired the actuators and cord assembly may be arranged to operate a warp hook or heddle for positive two-way reciprocation or, in an alternative embodiment of the invention shown in Figure 2, an actuator 1 may be directly connected to the warp hook 8 which carries an eye 3 at its lower end receiving the corresponding warp thread W at the shed S. The hook 8 is guided at 9 for vertical reciprocating axial movement. Having regard to its vertical position the actuator 1 may be spring loaded at 11 to assist return movement for satisfactory operation whilst the correct extent of operation of the actuator 1 is monitored at 6. Reciprocation of the hook 8 may be also monitored or alternatively monitored. Here again the actuator arrangement is of compact form to suit the close spacing together of warp hooks 8 and the actuators 1 only require low power operation. If necessary for suitable disposition of the actuators 1 they may actuate the hooks 8 through linkage such as bell crank mechanism or by Bowden cable or similar connection as at 12 in Figure 3 and which is applicable to the arrangement of Figure 1 (as shown) or direct Bowden cable connection may be effected between the actuator 1 and a heddle 8. The Bowden cable 12 is shown located through a comber board 13. Guided rod connection (e.g. in nylon guides) may be employed or connection by rigid or flexible carbon fibre rods or the like. Sensing means is shown provided at 17 for detecting incorrect movement or non-operation of the heddle 8. As will be clearly evident from the foregoing shedding of the warp threads W can be effected by the actuators 1 and cords 2 (Figure 1) or the actuators 1 (Figure 2) in a simple, inexpensive and effective manner and with a positive action in weaving an endless variety of patterns, designs or the like. As well as low electrical power consumption it is believed that high speed operation of the shedding motion should be obtainable e.g. of the order of 1200 picks per minute of weft thread operation. The actuator arrangements according to this invention and loom control effected by them enable Jacquard mechanism to be dispensed with resulting in considerable reduction in initial installation expenditure and subsequent running costs. Thus Jacquard mechanism entails the use of substantial crank or cam driving gear for raising and lowering the hook carrying griff against spring loading of the order of 1 Kg per warp thread all of which requires a considerable amount of power to operate the driving gear as well as substantial support structure for the latter. A further disadvantage of Jacquard mechanism is that despite electronic or electromagnetic selection of warp hooks for operation, malfunction of a hook or hooks can occur and which usually cannot be checked until resulting faults appear in the woven fabric. In contrast the positive operation of the warp threads by the actuator arrangements of the present invention and the monitoring which can be readily effected virtually eliminate faulty operation. Further practical advantages and applications of the invention will be apparent from the following. Thus owing to the computerised operation of the actuators it can be readily arranged for all the warp threads W to be brought to a "centre or closed shed" position Figure 4 i.e. in the same plane from the operative open shed condition. This enables all the warp threads to be kept under substantially the same reduced tension when the loom is not in operation over a period of time. Individual actuation of each warp thread greatly facilitates setting up of a loom with fresh warp threads since the eye or eyes 3, can be selectively brought to a convenient and readily ascertained position for threading of warp thread through the or each eye. Sequential setting up procedure can be provided by the computer or microprocessor from model pattern formats. Actuator arrangements according to this invention are capable of effective application where oblique or parabolic shedding is required i.e., by appropriate control of the actuators 1 as respectively indicated in Figures 5 and 6 so that required warp thread operation is obtained. The computer or microprocessor determines the geometry of the shed functions i.e. its size and shape. This information is stored in a memory or can be established using positioning devices such as potentiometers or switches as appropriate. The speed of how the shed size and shape is operated is also programmable as per the computer or microprocessor or by a suitable electrical speed setting device. Pattern and/or obliqueness data can be entered into the computer through either its keyboard or from a host computer by means of eprom, disc, ram card, serial link, parallel link or by network as appropriate or by any other memory data transfer device. The operation of the apparatus can be checked directly by the computer or by the synchronisation of an external source. Thus the computer using the control data is able to advise and report on the management and performance of the whole apparatus including predicting the possible failure rates prior to their occurrence thus providing a schedule of preventative maintenance routines. The use of appropriate software enables the computer or microprocessor to hold in its memory the optimum operating conditions for each of the woven cloths. It therefore not only undertakes the controlling aspects of the sequence of operation of the loom in performing its process operations but also the management of them and the reporting of both the completed work as well as any faults or failures which may have occurred which information can be provided by suitable display means. The software system for the purpose of this invention can have the necessary architecture to fulfil these requirements together with fault diagnostics either for stand alone single purpose machines or for fully integrated machines working from a host computer. As well as the foregoing the software enables the computer to provide setting up procedures and operation from any of a wide range of patterns or the like stored in the computer memory such that by simple classification and coding routines any pattern can be selected and called up instantly for immediate use. When it becomes necessary to effect seaming or joining of woven material in a suitable weaving machine the software further enables the splice point to be varied continuously using a spaced randoming algorithm suitably weighted to avoid bunching and to maximise and optimise the strength of the joined section automatically and in a manner which has not been hitherto readily available. It is to be understood that the invention herein defined and described includes the method of loom control provided as well as the means for effecting such control.

Claims: A weaving machine having apparatus for controlling the movement of healds (3) for moving yarn (W) to form a fabric of a selected pattern; a plurality of electronically controlled electric actuators (1); each actuator has connection means (2, 2 1 , 8) for connecting it to a respective one of said healds (3); each actuator is independently actuable to move said respective heald in a substantially linear movement between first and second extreme positions; computer means having a memory for storing data representing selected operating parameters for producing a preselected textile pattern; said computer means having data transfer means for inputting said data into said memory; said computer means is operable to control actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said respective heald (3) into a selected one of said first and second extreme positions; said first and second extreme positions are variable in response to said selected operating parameters to produce said preselected textile pattern; said first and second extreme positions being controlled by said computer means in response to stored data representing said selected operating parameters thereby to enable oblique or parabolic shedding during operation; means (6, 7) forming part of a feedback closed loop system in a diagnostic routine for monitoring movement of each said heald (3) between said extreme positions in response to actuation of the associated actuator (1) by said computer means thereby to indicate deviation of said movement from normal operation including incorrect linear movement. Machine as claimed in claim 1 wherein said computer means is operable to control actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said heald (3) into a selected one of said first and second extreme positions and a preselectable third position intermediate said first and second positions. Machine as claimed in claim 1 or 2 wherein said connection means (2) comprises an endless mechanical loop. Machine as claimed in claim 1 or 2 wherein said connection means includes Bowden cable means (8). Machine as claimed in any of claims 1 to 4 wherein said actuator is operable to drive rotatably a drum member about which said connection means (2,2 1 ,8) is wound, whereby to move said connection means along its own path in a forward or reverse direction. Machine as claimed in any of claims 1 to 5 further comprising tensioning means (5,11) for tensioning said connection means (2,8). Machine as claimed in any of the preceding claims wherein said computer means is operable to stop operation of said weaving machine in response to said deviation. Machine as claimed in any of the preceding claims wherein said monitoring means (6,7) comprises a sensor and a cooperating member on said connection means. Machine as claimed in any of the preceding claims wherein said computer means is operable to control actuation of said actuators (1) for bringing said healds to a centre shed position. Machine as claimed in any of the preceding claims wherein the positions of said healds (3) define the shed of the machine and said operating parameters comprise the size and shape of the shed and the speed of change of said size and shape. Machine as claimed in any preceding claim wherein each said actuator (1) is operable to move the heald between said first and second positions at a speed of up to 1200 picks per minute of weft thread operation. A method of controlling the movement of healds (3) in a weaving machine to form fabric of a selected pattern, the method comprising the steps of: providing a plurality of electronically controlled electric actuators (1) each of which is connected to a respective one of said healds (3) and independently actuable to move said heald in a substantially linear movement between first and second extreme positions; storing data representing selected operating parameters for producing a preselected textile pattern; controlling actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said heald (3) into a selected one of said first and second extreme positions; connecting each said actuator (1) to said respective heald (3) by connection means (2,2 1 ,8), said actuator being operable to move said connection means along its own path in a forward or reverse direction, to move said heald between said first and second positions; controlling locations of said first and second extreme positions in response to said stored data representing selected operating parameters to produce said preselected textile pattern thereby to enable oblique or parabolic shedding during operation; and using a feedback closed loop system in a diagnostic routine to monitor movement of each said heald (3) between said first and second extreme positions in response to actuation of the associated actuator (1) thereby to indicate deviation of said movement from normal operation including incorrect linear movement. A method as claimed in claim 12 further comprising controlling actuation of said actuators (1) in a preselectable manner in dependence on said data to cause each said actuator selectively to move said respective heald (3) into a selected one of said first and second extreme positions and a preselectable third position intermediate said first and second positions. A method as claimed in claim 12 or 13 wherein the step of connecting each said actuator (1) to said heald (3) by connection means includes connecting an endless mechanical loop (2) including said connection means. A method as claimed in claim 12 or 13 further comprising tensioning said connection means. A method as claimed in any of claims 12 to 15 further comprising stopping operation of said machine in response to indication of said deviation. A method as claimed in any of claims 12 to 16 further comprising monitoring the operation of each said actuator (1) and indicating a malfunction thereof. A method as claimed in any of claims 12 to 17 further comprising controlling actuation of said actuators (1) for bringing said healds to a centre shed position. A method as claimed in any of claims 12 to 18 wherein the positions of said healds (3) define the shed of the machine and said operating parameters comprise the size and shape of the shed and the speed of change of said size and shape. A method as claimed in any of claims 12 to 19 further comprising moving the head (3) between said first and second positions at a speed of up to 1200 picks per minute of weft thread operation.

Inventors: PALMER RAYMOND LESLIE, PALMER, RAYMOND LESLIE
Applicants: PALMER RAYMOND LESLIE, PALMER, RAYMOND LESLIE
Application year: 1989
Main classification: D03C3
IPC codes: D03C13, D04B15, D03C3