GB2027945A

GB2027945A - Looms having electronic control systems

Info

Publication number: GB2027945A
Application number: GB7927480A
Authority: GB
Original assignee: Sulzer AG; Gebrueder Sulzer AG
Current assignee: Sulzer AG
Priority date: 1978-08-09
Filing date: 1979-08-07
Publication date: 1980-02-27
Also published as: SU934911A3; FR2433066A1; IT1122437B; AT364327B; IT7924936A0; DE2836206A1; DE2836206B2; JPS5526293A; ATA602078A

Abstract

In a loom, an encoder (12, 13) is provided on the main shaft (4) to indicate continuously the main shaft angular position. The angular position is fed from the encoder to an electronic decoder (16). A number of lines (18 to 23) each programmed to become energised at a specific main shaft angular position is accommodated in a pegboard matrix (17). When the main shaft reaches a programmed angular position, a corresponding actuating element (26 to 31), e.g. a solenoid valve for a weft insertion nozzle (6, 33 to 41), is actuated by each line. It is thus possible to actuate a relatively large number of components of the loom at each required main shaft angular position. The time of actuation within the loom cycle, or the duration of the actuation, e.g. the time during which an air nozzle is open, can be readily adjusted during operation and hence adapted to requirements at any time. <IMAGE>

Description

SPECIFICATION Looms having electronic control systems This invention relates to looms and more particularly relates to an electronic control system for a loom, especially but not exclusively a loom with jet weft insertion.

In a loom described in German Offenlegungsschrift 2625 634 there are auxiliary nozzles along the line of pick and the signal sequence for successively actuating the auxiliary nozzles is initiated by a single sensor scanning the position of a moving part of the loom. Each nozzle other than the first is then opened by a signal produced when the preceding nozzle closes.

The disadvantage of this is that only the beginning of the signal sequence is dependent upon the position of the loom main shaft. The opening time and duration of opening of each auxiliary nozzle are dependent upon the opening time and the duration of the opening of a preceding auxiliary nozzle. If, for example, the time during which one nozzle is open is adjusted, the opening times of all the subsequent nozzles are automatically also influenced. For example, if the duration during which one of the nozzles is open is increased, the opening times of all the subsequent nozzles occur later.

The opening times and the opening duration of the individual nozzles cannot therefore be controlled individually or adapted to requirements individually during operation.

According to the present invention, a loom has a device which operates in synchronism with the main shaft of the loom to produce signals indicative of the rotational position of the loom, at least one component of the loom being controlled in dependence on the angular position of the main shaft via an electronic programmable store. Preferably the said device comprises an angular position encoder which operates in synchronism with the main shaft of the loom and an electronic decoder connected to the encoder to produce the said signals. The main shaft angular position can thus be taken off electronically throughout the whole weaving cycle.Electronic control signals can thus be taken off from the decoder, e.g. by appropriately pre-programmed stores, e.g. pegboard matrices, or semi-conductor stores (ROMs), when the main shaft is in any desired angular position, to operate components of the loom. There is therefore a completely individual control for the individual components, e.g. for the auxiliary nozzles along the line of pick or for the weft yarn cutting means. The components concerned may be controlled or actuated at a specific main shaft angular position or at a number of main shaft angular positions, within one working cycle of the loom. For example, the auxiliary nozzles of a loom with jet weft insertion can be controlled in respect of their opening and closing times and hence in respect of their individual opening duration, and be adapted to specific requirements even during operation.

The invention may be carried into practice in various ways but one loom embodying the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure lisa diagrammatic elevation of the loom viewed from the cloth side; Figure2 is a diagram showing certain components of the loom; and Figure 3 is an operating diagram for the loom.

The loom shown in the drawings comprises two side frames or cheeks 1,2 forming part of the loom frame, a cloth beam 3, a main shaft 4, a picking motion 5 with a main nozzle 6 for inserting a weft yarn 9 which is taken from a weft bobbin 8, which remains outside the shed, a catching motion 10, and an air supply duct 11 connected to a compressed air source.

An angle encoding disc 12 is mounted on the main shaft 4 and rotates therewith, and hence in synchronism therewith. It comprises, for example, opaque arcuate portions 82 shown in Figure 2 as continuous lines, and transparent arcuate portions 81 shown as dotted lines, these portions being arranged around a number of circles. During operation, these sectors can be scanned by a scanning head 13 which, for example, contains a number of photo-diodes 80. The parts 12, 13 thus form an encoder for the instantaneous angular position of the main shaft 4. On a complete revolution of the main shaft, 180,360 or 720 different electronic configurations, for example, are transmitted via the multi-channel line 14to a decoder 16.

A matrix pegboard 17, which may, for example, be constructed as a crossbar distributor, is connected to the decoder 16 via a multi-channel line 10'. Control lines 18 to 25 run from the pegboard 17 for various components of the loom which are to be controlled when the main shaft 4 is in specific angular positions, or are to be actuated at certain times during the cycle.

Line 18 is connected to a solenoid valve 26 for actuating (opening or closing) the main nozzle 6.

Lines 19 to 23 are taken to solenoid valves 27 to 31 for actuating auxiliary nozzles 33 to 41 disposed along the picking path 32, i.e. along the shed. The auxiliary nozzles, 33,34; 35, 36; 37, 38; 39,40 are connected in pairs parallel to one another, and are therefore jointly opened or closed each time. In this example the auxiliary nozzle 41 is a single nozzle.

The control lines 24, 25 are connected to actuating elements of weft thread shears 42,43 disposed on each side of the shed. The solenoid valves 26 to 31 are connected to, and are fed by, the air duct 11 via compressed air supply lines 61 to 66.

The loom operates as follows. The distributor 17 contains a number of stores formed by the lines 91 to 96 in this example. Lines 91 to 96 are pre-programmed, by electrical plug-in pins 46, to a specific angular position of the main shaft in each case. Through the agency of the angular position encoder 12, 13, the angular position of the main shaft 4 is always available electrically in the decoder 16. As soon as the current angular position at the disc 12 coincides with a programmed angular position of one of the stores 91, 96 those of the actuating elements 26 to 31 involved receive a control signal.

Referring to Figure 3 (x-axis = angular position of main shaft in degrees), the main nozzle 6 is kept open, for example, between 100" and 300 (section A = weft insertion). The auxiliary nozzles 33,34 are kept open approximately from 100.048 to 140 (section B), the auxiliary nozzles 35, 36 are kept open from 120"to 1600 (section C), and soon. The opening times of consecutively controlled auxiliary nozzles may overlap, as is the case with the nozzle pairs 33, 34; 35,36; 37,38 (sections B to D). Gaps 71,72 may also be provided between consecutive air pulses (sections D, E and E,F).Figure 3 does not show the actuation of the shears 42, 43. In a modified construction, the main nozzle 6 and the auxiliary nozzles 33 to 41 are controlled consecutively, i.e. there is no overlap.

The times of actuation of the individual components of the loom, e.g. opening and closing of the individual nozzles, cutting by the shears 42,43, and so on, can be adjusted to any desired main shaft angular positions by re-programming the store 17 by means of the pins 46.

A change-over may also be made during weaving to try out which main shaft angular positions are appropriate for the individual components and how long, for example, the individual nozzles should receive air pulses. The time during which the individual components are operated (opening and closing of the nozzles, operation of shears and so on) depends, for example, on the weft material 9 for picking and/or other operating variables.

It is possible to control other components of the loom from the angle encoder 12, 13 and store 17 in addition to or in place of the nozzles and shears, for example weft thread brakes and stop motions.

The angular position encoder comprising the parts 12, 13 is a device whereby the angular positions of the main shaft 4 are detected and processed in a predetermined regular distribution over one complete revolution of the shaft (e.g. at 180 intervals each of two degrees, or at 360 intervals each of one degree or 720 intervals each of half a degree, and so on).

The solenoid valves may be replaced by mechanical actuating elements, e.g. electrostrictive bender strips. The opaque and transparent sectors 82, 81 on the angle encoding disc 12 may be replaced by raised and recessed metal sectors which can be scanned, for example, by sensors (proximity switches) contained in the scanning head 13. A separate decoder 16 may be dispensed with if the signal sequence delivered by the angle encoder 12 can be directly fed on line 14 to the store 17. If required the store may also include a decoding function. However, it may be possible for decoding to be completely dispensed with by transmitting the signal sequence delivered by the angle encoder 12 directly via the control lines 18 to 25.

Claims

1. A loom having a device which operates in synchronism with the main shaft of the loom to produce signals indicative of the rotational position of the loom, at least one component of the loom being controlled in dependence on the angular position of the main shaft via an electronic programmable store.

2. A loom as claimed in Claim 1 in which the said device comprises an angular position encoderwh.ch operates in synchronism with the main shaft of the loom and an electronic decoder connected to the encoder to produce the said signals.

3. A loom as claimed in Claim 2 in which the electronic programmable store for generating control signals for the component to correspond to selected main shaft angular positions, is connected between the angular position encoder and the component.

4. A loom as claimed in Claim 2 or Claim 3 in which the angular position encoder comprises a control disc fixed on the main shaft and an electrical scanning head for scanning the angular position of the disc.

5. A loom as claimed in any of the preceding claims in which the store comprises a matrix which is adapted to be programmed to specific angular positions and which, when the main shaft angular position coincides with one of the said positions, delivers a control signal for the component being controlled.

6. A loom as claimed in any of the preceding claims which has jet weft insertion means.

7. A loom as claimed in Claim 6 in which the jet weft insertion means includes auxiliary nozzles along the line of pick which have actuating elements controlled successively from the store according to the angular position of the main shaft.

8. A loom as claimed in Claim 7 in which the opening time and closing time of each auxiliary nozzle in the weaving cycle and hence the duration of opening of the auxiliary nozzle are independently programmable in the store.

9. A loom as claimed in any of the preceding claims in which the programmable store is a matrix pegboard.

10. A loom substantially as described herein with reference to the accompanying drawings.