GB879574A - Improvements in or relating to stop motions for warping machines - Google Patents

Abstract

879,574. Warp stop-motions. RUTI MACHINERY WORKS Ltd. Dec. 23, 1957 [Dec. 28, 1956], No. 39957/57. Class 142(1) In a warp stop-motion having a feeler for each yarn, the failure of a yarn causes the feeler to complete a circuit whereby a thyratron will fire and a relay will cause the loom to stop. In one embodiment (Fig. 2), each yarn passes over a feeler 19 urged upwards by a spring 25, the gearing being guided between guides 31. When a yarn fails, the feeler 19 moves upwards to engage a contact 24 thereby closing a contact 50 (Fig. 3). A condenser 47 is charged gradually and when the voltage of an electrode 43 reaches the ignition value the thyratron fires and a relay 44 operates a contact 51 in the circuit of an electromagnet which stops the machine. The slight delay in firing can be adjusted by suitable choice of the condenser 47 and of a resistance 49. If no time lag is required, the condenser can be dispensed with. In a second embodiment (Fig. 5) the feeler 71 pivots about a shaft 64 and on yarn failure the respective feeler falls and engages a rod 75 thereby causing the turned down end 65 of the shaft 64 to close the contact 50. With either embodiment, the circuit contains a spring loaded switch 46 which when opened extinguishes the thyratron and when reclosed restores the stopmotion to its initial position. Alternatively, a resistance is inserted between the relay 44 and one pole of the current source and a normally open switch is provided between the end of the resistance remote from the one pole of the source and the other pole of the source whereby on closure of the switch the source is short circuited and the relay is de-energized. Each thyratron 40 is arranged in an upright member 10 at the same level as its associated group of feelers to provide a visual indication of yarn failure.