Patent GB-1321935-A (GB)
Title: Motor vehicle steering column assemblies
IPC: B60R25/02
Filed: 1971-12-09
Abstract: 1321935 Anti-theft devices GENERAL MOTORS CORP 9 Dec 1971 [18 Dec 1970] 57251/71 Heading B7J [Also in Division E2] A motor vehicle steering column assembly comprises a steering shaft 18 rotatably mounted within a support column mounted on the vehicle and operatively connected to steering gear of the vehicle, a keeper plate 58 rotatable with the shaft 18 and extending therefrom transversely of the support column, a steering shaft lock bolt 62 mounted on the support column and movable into and out of locking engagement with the keeper plate and a lock having a sleeve member 38 secured to the support column and a cylinder member 36 rotatably supported by the sleeve, the cylinder member having a slot 42 in which a key 54 is insertable to free the cylinder member for rotary movement. There is a connection between the cylinder member and the bolt 64 to move the bolt into and out of locking engagement with the plate 58, a latch 86 supported by the support column and movable into engagement with the bolt to prevent movement of the bolt into engagement with the plate, and movable out of engagement with the bolt to permit movement of the bolt into engagement with the plate. A pawl 114 is movable out of a cavity 112 in one of the members into the key slot for engagement with the key and by such engagement to be moved back into the cavity and be retained therein, in which position the pawl effects movement of a push rod 102 on the support column into engagement with the latch 86 so as to move the latch into engagement with the bolt 62 and thereby hold the bolt out of engagement with the plate 58. As shown, a shift bolt 24 which is connected by a rod 30 to an ignition switch and other electrical accessories, includes a rack 32 engaged by a toothed sector 34 rotatable with the lock cylinder 36 which includes large and small diameter portions 44, 46, defining a shoulder 48 spaced from end surface 50 of the sleeve. Upon insertion of a coded key 54 into the lock cylinder, the side locking bar of the cylinder lock is withdrawn to allow rotation of the lock cylinder from a locked position to a position wherein the sector 34 causes translation of the bolt 24 leftwardly and simultaneously moving the ignition switch to "on" and slidably withdrawing the lock bolt 62 from one of a series of recesses or notches 60 in the keeper plate 58. The bolt 64 has a groove 64 bounded by a shoulder 70 and a retaining flange 72, and is connected with the shift bolt 24 by a fork 76 of the bolt 24 hooked over the end 68 of the bolt 64 and engaged by a spring 78; means to prevent relocking movement of the bolt 64 includes the pivoted latch 86 which engages the surface 66 of the bolt in a latched position thereof, a blocking arm 88 and a tab 90, and a pivoted intermediate lever 92 having a foot 94, a spring 96 urging the latch and lever in opposite directions until the edge of the tab 90 engages a lifting edge 98 of the lever. The push rod 102 is slidable in a groove 104 in the housing 26 and bears at one end against the foot 94 and the other end has a tab 108 received in a groove 110 in the portion 44 of the lock cylinder; the groove has a cavity 112 communicating with the key slot 42. The key-engaging pawl 114 is connected to an actuator 118 which overlaps the tab 108. A surface 122 of the key 54, when inserted into the lock cylinder, engages and pushes the pawl 114 along the key slot when the actuator 118 moves the push rod 102 downwardly to the retracted position, shown in Fig. 6, to engage the foot 94 and rotate the lever 92 against action of the spring 100. The latch 86 is also rotated until the spring 96 urges the latch in a counterclockwise direction. Unitary movement of the actuator and pawl continues until the pawl is cammed off the surface 122 of the key and into the cavity 112 when the side surface 124 of the key retains the pawl in the cavity, the push rod being then depressed to the retracted position and the tab 108 passing beneath the shoulder 48 to hold the push rod in that position, the key at this time having been fully inserted into the lock to withdraw the tumblers thereof and free the lock for rotational movement and thereby move the shoulder over the tab. Rotation of the lock cylinder withdraws, via the rack 32 and sector 34, the lock bolt 62 and the blocking arm 88 engages the surface 66 of the groove 64 to retain the bolt in the unlocked position. Withdrawal of the key releases the pawl 114 from the cavity 112 to remove the restraint provided by the actuator 118 on the push rod 102 when the spring 100 rotates the lever 96 clockwise whereby the edge 98 thereof engages the tab 90 of the latch 86 to pivot the latter and remove the arm 88 of the latch from the groove 64 so that the spring 78 projects the bolt 64 to the locked position.