GB319922A - Improvements in electric switches - Google Patents

Abstract

319,922. Fahy, F. C., Wilkinson, W. K., and Parkinson, J. W. Sept. 21, 1928. Star-delta starters in which movement from the neutral position to the delta position is prevented and when the allowable movement to the star position for starting has been made the movement to the delta position must be effected rapidly have a toothed cam e on the switch shaft normally serving, in the neutral position, to prevent anticlockwise movement of the shaft (to the delta position) bv its engagement with a pendulous catch g. Clockwise movement to the star position is possible, see Fig. 4, and thereafter the shaft may be turned rapidly through the neutral position to the delta position. If the movement is slow the pendulous catch has time to engage the toothed cam in the neutral position and prevent completion of the movement. The switch shaft is normally held in the neutral position by spring-connected centralizing levers j engaging a projection i on the shaft. In the delta position a catch n engages a pin o and the catch can be freed by hand through the rod q or automatically by a no-volt or overload coil.