Ignition switch with plate-latching means preventing movement from on to start once started

Claim 1

An ignition switch including a casing, a rotor mounted for rotation within the casing from a stable first position to a stable second position and from the stable second position to an unstable third position from which it is resiliently urged back to the stable second position, an arcuate cam track on the inner surface of the casing and including surfaces which extend radially of the casing in planes generally at right angles to the axis of rotation of the rotor, a spigot projecting from one face of the rotor and rotatable with the rotor, a latch member rotatable with the rotor the latch member being in the form of a rigid plate having therein an aperture through which said spigot extends to drivingly couple the rotor and the latch member, the latch member including an integral finger which extends radially into engagement with said cam track, and a resilient member acting on said latch member, said resilient member acting to urge said finger into engagement with said cam track and being capable of urging the finger radially outwardly when the finger is moved radially inwardly by the cam track during rotation of the rotor and the arrangement of the finger and the cam track being such that the rotor is prevented from movement from its second position to its third position unless the preceding movement of the rotor was from its first position to its second position.