ES372474A1 - Ignition switches - Google Patents

Abstract

An ignition switch, for use in combination with key operated steering column locks for road vehicles, comprises a casing 11 including a base 13, fixed contacts 29, 31, 32, 33 and 34, Fig. 3 (not shown), on base 13, a rotor 14, a movable contact plate 21 rotatable with rotor 14, and movable contacts 22, 23, 24, 25, Fig. 3 (not shown), on contact plate 21, the movable contacts being engageable with certain of the fixed contacts in predetermined angular positions of rotor 14 to complete electrical circuits between certain of the fixed contacts. The movable contact plate 21 is urged towards base 13 so that the movable contacts engage base 13, and co-operating camming means 26, 27, 30 are provided on contact plate 21 and base 13 which are operable in certain angular positions of rotor 14 to move at least part of contact plate 21 away from base 13 to prevent completion of electrical circuits between certain of the fixed contacts which, in the absence of the camming means, would be completed by contact plate 21. As shown, movable contact plate 21 is made flexible by split 28. Part of plate 21 is moved away from base 13 either by tilting or by flexure. A diagrammatic representation of the positions of the initial contacts is given in Fig. 3 (not shown). Detent means (not shown) are provided between rotor 14 and casing 11 to define the rotor positions. In the first position (Fig. 3a) the steermg column is locked and only the hazard warning light circuit is completed. In the second position (Fig. 3b) the hazard warning circuit is broken and the accessories circuit is completed while the steering column is unlocked. In the third position (Fig. 3c) all the electric circuits controlled by the switch are broken with the steering column unlocked. In the fourth position (Fig. 3d) the steering column is unlocked and the ignition and accessory circuits are completed. In the fifth position (Fig. 3e) the ignition and starter motor circuits are completed and the steering column is unlocked. The detent means does not retain the rotor in its fifth position and on release the rotor is spring urged back to ist forth position. The switch includes a latch (not shown) which when the switch has been moved from its fourth to its fifth position and then back again prevents the switch being moved again to its fifth position without first being returned to its third position. When the switch is to be used in a vehicle equipped with an alternator, base 13 carries further fixed contacts 35, 36, Fig. 3 (not shown), in the alternator field winding circuit which are bridged by piece 37 in the fourth position of the switch.