Patent GB-458289-A (GB)
Title: Improvements in or relating to apparatus for stopping electrically driven looms
IPC: H02P3/06
Filed: 1935-11-13
Abstract: 458,289. Control of motors ; stopping looms. SCHORCH - WERKE AKT. - GES., Rheydt, Rhineland, Germany. Nov. 13, 1935, Nos. 31409 and 31410. Convention dates, Nov. 16, 1934 and Oct. 1, 1935. [Class 38 (iii)] [See also Group IX] The driving motor of a loom is stopped by reverse-current braking by means of a single switch element automatically controlled by control circuits and electromagnetic switches without the use of mechanical locking devices, in such a way that on the occurrence of a disturbance in the loom the switch element is moved from an operating position to a reversecurrent braking position and maintained there until the driving motor has come to rest and travelled an adjustable predetermined amount in the reverse direction, whereupon the switch element is moved to a final stopping position to disconnect the motor circuit. The disturbance may be the breakage of the weft thread which causes a member 2, Fig. 1, to move to the right thereby operating a pawl 55 to free a member 47 which moves under the influence of a spring 52 and frees a switch 56 and causes contacts 7 to close. A switch operating coil 28 is thus energized and actuates its armature 29 to open contacts 20 thereby de-energizing another operating coil 16 which has held the switch lever 25 in a normal operating position V. The coil 28 then operates the switch lever 25 to its position R to effect reversal of the driving motor. The circuit of the coil 28 includes contacts 51 of an auxiliary switch which is opened by a member 11 when the driving motor has come to rest and travelled in the reverse direction to an adjustable extent determined by adjustment of a stop 12. The opening of the switch contacts 51 de-energizes the coil 28 and the switch lever 25 moves to its " off " position to disconnect the motor. Reverse running may be obtained at will by closing a hand switch 43. Further contacts such as 33, connected in parallel with the contacts 7 may be operated in response to other disturbances such as the shuttle coming to rest before reaching the end of its throw. To start the loom a hand lever 18 is moved from a left " off " position b, Fig. 1a, to an extreme right position c where it is held during the first pick. By this operation a member 42 is moved to the right and moves, by means of a pin 45, the member 47 which closes contacts 56 to energize the coil 16 and move the switch lever 25 to its operating position V. While the lever 18 is held to the right the member 2 is rendered ineffective, but after the first pick, when the lever 18 is released, and moves to an intermediate position a, the member 47 is held by the pawl 55, and the automatic stopping mechanism is set. The loom is stopped at will by releasing the lever 18 which is moved by a spring 39 to the position b, the member 42 opening a stop switch 50. Where, as in Jacquard looms, for instance, parts of the machine are not reversed, they are uncoupled from the drive when reverse braking is effected by means under the control of a coil 44 connected in parallel with the coil 28. The coil 16, in addition to operating the switch lever, closes self-maintaining contacts 23, and the initial circuit of the coil 28 includes contacts 36, 38, closed when the coil 16 is energized. The energization of the coil 28 is maintained, when the coil 16 is de-energized and the contacts 36, 38 opened, by means of contacts 37, 36, closed by the coil 28, and, in addition, when the motor is disconnected and the machine is being manipulated by hand, the contacts 51 do not effect energization of the coil 28.