Switch with shape memory element for remote operation - employs abrupt contraction of heated wire to exert pull on linearly movable button with return spring

摘要

The switch housing (1) encloses a blade (2) with moving contacts (2a,2b) on a carrier (5). A latch (6) is operated by a pushbutton (7) working against a helical spring. For remote operation a wire (9) of shape memory alloy connecting two electrical terminals is wound around a number of posts (10) and linked to the pushbutton (7). When heated to about 85 deg.C by current from a remote control receiver, the wire (9) contracts and exerts tractive force on the pushbutton. ADVANTAGE - Simpler and more efficient device executes a longer linear movement at constant force with less energy consumption.