GB441774A - Improvements in and relating to driving mechanisms - Google Patents

Abstract

441,774. Actuation of switches. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London, and SARGEANT, C. J., Mark Ash, Dunsmore Avenue, Hillmorton Paddox, Rugby. July 24, 1934, No. 21642. [Class 38 (v)] In a driving mechanism, which may be used for operating transformer tap-changing switches, a motor drives through lost-motion an intermediate shaft fitted with a spring which is moved over a dead-centre position beyond which the stored-energy is released to rotate the shaft, a second intermediate-shaft being driven by the first-mentioned shaft through a lostmotion drive, the second shaft driving the mechanism-operating shaft only during a portion of its rotation, thereby moving the operating mechanism itself from one step position to the next. As shown in the Figure the motor 1 rotates a driving cam 3 which engages with lost motion a pin 8 on an intermediate shaft 4. This pin after being moved through a semicircle brings a spring 10 across a dead-centre position so that the spring may moke the shaft freely through the subsequent semicircle. During this rotation of the member 4 and slightly before the dead-centre position is reached a pin 9 engages a further cam 5 attached to the driving disc 6 of a Genevastop mechanism the driven disc 7 of which rotates the operated device e.g. a tap-changing switch 2 through one step. If the spring 10 breaks, the motor, after taking up lost motion completes this action by positive drives. The stepping operation may be completed by the spring independently of the motor after the dead-centre position has been passed in the case of failure of motor supply.