GB419321A - Improvements in and relating to plug-in electric switches - Google Patents

Abstract

419,321. Plug couplings combined with switches. HAMPTON, J., The Laurels, Barr Common, near Walsall. July 22, 1933, No. 20677. [Class 38 (i).] A switch, comprising a spindle 14 with two barrels 17 carrying contacts 18 that bridge fixed contacts 11, 12, is biassed to the open position by a spring 20. This spring also presses the spindle axially forcing an oblique pin 24 on the spindle into engagement with a detent 26 cut in the wall of an earthing socket 10 so preventing the switch from being closed. The pin 24 enters the socket 10 sufficiently to be displaced by the earthing plug 10a, Fig. 5, thus unlocking the switch, which can then be opened or closed by rocking the lever 22. When the switch is closed the pin 24 enters a notch 27 in the socket 10 and by its engagement with the plug 10a retains the switch in its closed position. If the plug is withdrawn it allows the spring 20 to open the switch, this taking place before the live plugs leave their sockets. The action of opening the switch is accelerated by a spring 28 compressed by the plug 10<a> and engaged by a pin 25 on the spindle 14 when the switch is closed. The spring 28 thus acts against the spring 20 to move the spindle axially if the plug is withdrawn while the switch is closed. According to the Provisional Specification instead of the spindle moving axially to cause the pin 24 to engage the earthing socket, the pin 24 may be pivoted on the spindle and pressed by a spring towards the socket.