GB189824264A - An Improved Switch for Incandescence or Glow Electric Lamps in which the Filament is Subjected to a Preliminary Heating Effect apart from the Lighting Current. - Google Patents

Abstract

24,264. Hirst, H. Nov. 17. Switches for incandescent lamps having a filament and a heating- appliance. Fig. 1 shows the general arrangement and connections, H representing the heater. Two contact-bars B, B<1> are loosely mounted on a spindle A, and are connected by a spring S. F is a contact common to both, and D and E are connected to the circuits as shown. On turning the bar B<1> by a suitable handle, the contact-bar B first connects up the lighting-circuit at D, resting against a stop g. Further movement of the bar B' puts tension on the spring S, and closes the heating-circuit by making contact at E. On releasing the handle, the bar B' is pulled off the contact E, so breaking the heating-circuit but leaving the lighting-circuit closed. Instead of having rotary contacts, sliding bars or other suitable arrangements may be employed.