GB1433145A - Automatic restart system - Google Patents

Abstract

1433145 Controlling A.C. motors A A KRYSZEK 1 June 1973 [8 June 1972] 26375/73 Heading H2J [Also in Division D1] A system for controlling an apparatus comprises a stop motion device for stopping operation of the apparatus and for actuating a timing device which remains actuated for a predetermined time and means for preventing reinitiation of operation of the apparatus if the stop motion device remains actuated at the end of the predetermined time. A knitting machine comprises devices 16, 18 for closing one or both of a pair of contacts 27, 47 should the tension in the yarn 10 being knitted have an abnormal value. For automatic restart type of operation of the machine a switch S1 is closed and the machine is started by momentary depression of a push-button switch 48. Relay B is thus energized which causes energization of control relay C and contactor A so that a motor 24 is energized to run the machine. Whilst the motor is running a relay E is energized which opens contact E1 to inhibit operation of a timing device T. Should an improper tension develop in the yarn 10 one or both of the switches 27, 47 close and relays F, D are energized. Contacts D1, D2, F1 open so de-energizing contactor A to stop the motor 24. Relay E de-energizes to close contact E1 whereupon the timing device T is actuated, relay C remaining actuated by relay B is disabled by the open contact D1. After a predetermined time (say 4 seconds) the timing device T closes contact T1 and opens contact T2. If after this time an improper tension still exists the relays F, D will still be energized so preventing re-energization of contactor A and the relay C will become deenergized to shut down the machine. Should the normal tension be restored during the time the relays F, D will be de-energized so that on closure of contact T1 the contactor A will reenergize to restart the motor 24 and the relay C will remain energized by the closure of contact D2.