The invention relates to a cordless thread control device according to the preamble of claim 1.
A cordless thread control device of the type initially mentioned is known, for example from GB 1 219 012 A. A driver for the thread, said driver being designed as a steel lifter, has, on its end part facing a detaining device, a hook by means of which the steel lifter can be interlocked selectively with the detaining device. The hook has an arcuate configuration, in order to give the end part of the driver elastic properties intended to, bring about a damping of the interlocking of the hook with the detaining device. Due to the arcuate and resilient design of the hook, the latter is unstable in the longitudinal direction of the steel lifter, with the result that a reliable interlocking of the driver with the detaining device is not ensured. This may lead to an inaccurate operation of the thread control device, to a reduction in the rotational speeds and, finally, to weaving errors in the cloth web produced.
The object of the invention is to design a thread control device of the type initially mentioned, in such a way that it does not have said disadvantages.
In the thread control device initially mentioned, the object is achieved, according to the invention, by means of the characterizing features of claim 1.
Since, in the thread control device, the driver is divided between the lifting device and the control means and the driver parts are connected via an elastic damper member and/or the driver is coupled contactlessly to the lifting device via an electro-magnetic field, acting as a damper, of an electromagnetic coupling device, the loads occurring during the interlocking of the driver on the detaining device are damped and, nevertheless, a reliable interlocking of the driver on the detaining device is ensured. The transmission of force in the thread control device is thereby damped, so that, particularly even in the case of high drive cycles, impacts are mitigated and therefore damage to the detaining means is reduced. This leads, in particular to substantially reduced wear and consequently to a longer useful life, along with an increased performance. Further, the generation of noise is reduced, thus resulting in improved working conditions for the operator.
Advantageous refinements of the thread control devices are described in claims 2 to 13.
It is particularly expedient if, according to claim 2, the damper is designed as a stop for the lifting device, since direct force introduction occurs here.
It is advantageous if, according to claim 3, the coupling device has a permanent magnet which is arranged fixedly on the driver and the pole of which is held suspended between two homopolar poles of a magnetic device which are arranged on the lifting device, in such a way that the driver can be driven as long as said driver is not detained in its movement by the control means. The poles of the permanent magnet may be oriented, according to claim 4, in the direction of movement of the driver or, according to claim 5, transversely to the direction of movement of the driver. It is particularly advantageous if, according to claim 6, the magnetic device of the lifting device is of permanent-magnetic design. However, an electrical design according to claim 7 may also be envisaged in spite of a complicated current supply.
A particularly compact type of construction is obtained if, according to claim 8, as seen in the weft direction and/or warp direction of the shedding device, a detaining device has the same division as the heddles guiding the warp thread.
A particularly flat and effective type of construction is obtained if, according to claim 9, the driver is configured as a flat lifter, one end part of which is configured directly as a control means which can be brought into engagement with a detaining member under the influence of an electromagnetic actuator. It is particularly advantageous, in this case, if, according to claim 10, the actuator is designed as an oblique-pole magnet and, according to claim 11, the end part is designed as a leaf spring. The end part of the driver may, according to claim 12, be provided with a locking recess which cooperates with the detaining member. According to claim 13, the driver cooperates with a return spring which is expediently arranged on the end part which faces away from the control means.
Exemplary embodiments of the invention are described in more detail below with reference to the drawings in which:
The thread control device contains the drivers 4 which have loops 18 through which the warp threads 2 are guided. The drivers 4 are prestressed in one direction, here, for example, downward, into the basic position by means of springs 20. An oscillating lifting device 22 with lift knives 24 engages via a stop 26 on the driver 4 and moves the latter up and down at the rhythm of the lifting device 22, specifically until the driver is blocked in the high position by means of the detaining device 28. The detaining device contains control means in the form a leaf spring 32 which is firmly clamped on one side and which can be pivoted out towards the driver 4 under the influence of an electromagnetic actuator 34, so that a hook 36 of the leaf spring 32 cooperates with a hook 38 of the driver and retains the latter in the upper position, the high shed position.
To damp the driver 4, the latter is divided, and the driver parts 4a, 4b are connected contactlessly by means of a damper 40 which is formed from an elastic member 42 engaging on the lifting knife 24 of the lifting device 22. The impacts of the lifting device which act on the stop 26 are thereby damped, with the result that a generation of noise, on the one hand, and a wear of the thread control device, on the other hand, are reduced in spite of a high drive power. In particular, as a result, the wear of the hooks 36, 38 of the control means 30 and of the driver 4 is appreciably reduced and consequently the service lives 25.of the shedding device are improved.
FIGS. 2 to 5 show a further thread control device which is designed in a similar way to the thread control device of
The drivers must have sufficient bending resistance in the direction of displacement and may consist of the most diverse possible materials, such as, for example, plastic, but are conventionally manufactured from steel.
Number | Date | Country | Kind |
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796/02 | May 2002 | CH | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CH03/00252 | 4/15/2003 | WO | 9/28/2004 |