Thread control device for a textile machine in particular for a shedding device

Abstract

The invention relates to a thread control device for a textile machine, in particular, for a shedding device, with at least one thread guide body (31) which may be displaced in one displacement direction by means of a positive drive (35) and in the opposite direction by means of a non-positive, pneumatic return device (36). The return device (36) thus comprises a cylinder / piston unit (64,54), the cylinder chamber of which (52) is connected to a compressed gas source (60) by means of a valve (56). An improvement in control is achieved when the valve (56) comprises a first valve seat (72) connected to the cylinder chamber (52) and a second valve seat (76), between which a valve body (82), provided with at least one throttle point (80), may be displaced, pre-tensioned in the rest position by means of a spring (84) against the first valve seat (72), in which the throttle point (80) is ineffective and the valve body (82) blocks the communication with the compressed gas source (60) when the valve body (82) is in contact with the second valve seat (76).

Description

technical field [0001] The invention relates to a thread control device for a weaving machine, in particular for a shedding device, according to the preamble of claim 1 . Background technique [0002] A large number of yarn control devices for weaving machines are known. The closest prior art according to WO 97 / 08373 discloses a yarn control device designed with a drive and with return means for the yarn guiding member. In this case, the thread guide part is movable in one direction of movement by means of a positively designed drive and in the opposite direction of movement by means of a nonpositive and pneumatically designed return device, This return device acts in the opposite direction on the positive drive of the positive transmission. [0003] The pneumatic return device has a cylinder / piston assembly whose cylinder chamber is designed with an overpressure valve and has a non-return valve connected to a compressed air source. In this case, the air pressure in the c...

AI Technical Summary

Problems solved by technology

[0007] The disadvantage of the above technical solutions is the high cost of electric / pneumatic actuation of the valves

Thus, the entire controller of the pneumatic drive of the yarn control device has a large number of elements, such as non-return valves, pressure relief valves, pressure relief valves and electronic control units, which makes the system more prone to failure

In addition, the efficiency of the loom decreases due to a corresponding reduction in the motor speed in order to drain the lubricating oil, which occurs every 15 minutes

Furthermore, a reduction in the motor speed can have a negative effect on the textile quality, e.g. it can lead to slight variations in the width of the produced fabric

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