GB150109A - Improvements in electric switches - Google Patents

Abstract

150,109. Myers, R. P. June 13, 1919. Thermal switches particularly adapted for flashlight advertising-apparatus, of the type in which a bow-shaped spring is employed in combination with an electric thermal expansion device, the spring snapping-over to give a quick break from one contact to the other. A T-shaped lever k is pivoted at f and carries a bow-shaped spring l normally held against one of the contacts m, n by a spring O. Two expansible cylinders q, r of thin metal are mounted on brackets s on the baseboard with their free ends in close proximity to two studs t, u carried by the crossarm e of the lever K. In the position shown in Fig. 1, the bow-spring l is contacting with the contact pin n, and current is flowing through the coils v wound around the cylinder r. This is thereby heated, expands, and presses against the pin u, tending to swing the long arm K about its pivot f and increasing the pressure of the bowspring l against the contact n. The bow-spring is finally bellied out in the opposite direction to make contact with the other pin m, the action thereupon being repeated.