Patent GB-1184270-A (GB)
Title: Locking System in Vehicle Steering Column
IPC: B60R25/00
Filed: 1968-11-28
Abstract: 1,184,270. Vehicle anti-theft devices. GENERAL MOTORS CORP. 28 Nov., 1968 [19 Dec., 1967], No. 56561/68. Heading B7J. [Also in Divisions E2 and F1] A motor vehicle steering shaft 26, having an end portion 30 splined to a steering wheel hub 32, and a concentric gear shift tube 42 splined to a gear shift bowl 36 adapted at 40 to receive a gear lever, are both rotatably mounted inside a support column 14 mounted on the vehicle and are lockable against rotation by releasing and turning the core 52 of a cylinder lock 46, mounted on a housing 18 provided on the support column, with a key 60 to cause bolts 74, 120 to slide in the same direction generally parallel to the longitudinal axis of the support column and engage with keepers 84, 106 secured on the shift bowl 36 and steering shaft 26 respectively. The bolt 74 has a raised stop portion 82 at one end which can be drawn into a slot 86 of the keeper plate 84 when the gear lever is in " Park " position, and a rack (76), Fig. 3 (not shown) at its other end is spring urged into engagement with teeth on a sector 62 splined to the lock core and rotatably supported on a shaft 66 press fitted at 68 in the housing 18. With the gear lever in " Park ", a cam projection 132 on the keeper 84 engages a spring 124 secured a one end to the bolt 120 to cause the spring to urge the bolt to move so that its other end engages in any one of a number of peripheral slots 108 about the generally disc-shaped keeper 106, and a cam projection 126 on sector 62 adjacent the rack (76) co-operates with a shoulder 128 on the bolt 120 to control such movement. A compression coil spring 98 is seated between the steering shaft bearing 28 and an annular flange 100 of a turn signal cancelling member, and keeper 106 is secured over member 100 by a snap ring 110 and to a cover-plate 112 by " noback " screws 114, i.e. having no head slots for conventional removal. A hub 20 is secured over the end of column 14 by " no-back " screws 22. Adjacent the cavity for the cylinder lock 46, housing 18 receives a buzzer switch (134), Fig. 5 (not shown) having contact blades, (136, 138) urged into contact by a radially movable plunger (140) in the lock when the key is inserted to complete a circuit to the horn relay when, in addition, a conventional door jamb switch controlling the vehicle interior lights is closed, i.e. when the driver's door is open. A switch 142, Fig. 1 (not shown) secured to the steering column 14 has an actuating rod 144 whose head 146 is secured to bolt 74 against longitudinal axial movement thereof so that actuation of lock 46 from the locking to unlocking positions closes selected switch contacts in the order: " ACC " for controlling vehicle circuits when the vehicle is immobile; " LOCK, " with the bolts engaging the kepeers; " OFF " with the bolts free; " ON " to control the ignition; and " START " to control the engine starter, automatic return from " START " to " ON "'being secured by spring means (not shown). Since the end 82 of bolt 74 only passes the slot 86 of keeper 84 when the gear lever is in " Park " position, the ignition cannot be cut off and the steering shaft locked when the vehicle is in use. If the lock 46 is forced inwards of the housing, a lug 71 on the sector 62 engages in a slot 73 in housing 18 to prevent rotation of the , lock core. In a modification, Fig. 8 (not shown), a further slot in keeper 84 and a stop on belt 74 ensure that " START '' is only reached by rod 144 when the gear lever is in " Neutral " and the lock bolt is initially in the " OFF " position, or whenever the gear lever is in " Park ". In a further modification, Fig. 9 (not shown), the bolt 74 has a yoke member to receive a reduced diameter portion of the bolt 120, and a compression spring seats on this portion between the yoke and the shoulder of the bolt 120. The spring and cam arrangements 124, 132 and 126, 128 are omitted. Where the steering wheel is tiltable with respect to the column about a universal joint (228), Figs. 10, 11 (not shown), the construction of the steering shaft lock is unaffected, but the teeth of sector 62 engage with the rack end of a member rotatably and slidably secured at one end over a boss portion of the housing and having an arcuate slot at its other end engaging a pin at the end of the gear shift locking bolt.