GB1423356A - Electric switch - Google Patents

Abstract

1423356 Inertia switches J S SHARPE 10 July 1973 [11 July 1972] 32263/72 Heading H1N An inertia switch particularly for use in a vehicle to operate under crash conditions, comprises a mass 21 Fig. 1 pivoted at one end 20 and yieldingly guided endwise as by spring 53 to hold contacts 49, 50 closed until the mass 21 is displaced transversely by an inertia force. A steel ball 23 at the top of the mass 21 engages a recess 29 in a bell-shaped member 48 which holds the contacts 49, 50 closed until the ball 23 clears a ridge 30 and engages an annular recess 31 in a pivoted disc 26. The bell-shaped member 48 is thereby permitted to drop and open the contacts 49, 50, which may cut off the vehicle ignition or isolate the battery. The disc 26 may also pivot against the action of a coil spring 25 to engage a contact 28 associated with flashing hazard warning lights on the vehicle. The assembly may be reset by raising a plate 36 coupled by rods 35 to a ring 34 which re-centres the disc 26 and yieldingly presses a plunger 18, 52 via spring 51 to centralise the mass 21 by engagement with the conical wall 22. In a modification Fig. 6 (not shown), the disc 26 may be suspended by a flexible ligament (38) which is raised or lowered via a screw (41) to vary the compression in the spring (25).