Patent GB-1106804-A (GB)
Title: Motor vehicle theft-prevention devices
Inventor: TURNEY ERIC JAMES
IPC: B60R25/021
Filed: 1965-08-18
Abstract: 1,106,804. Vehicle anti-theft devices. GENERAL MOTORS Ltd. 14 July, 1966 [18 Aug., 1965], No. 35393/65. Heading B7J. [Also in Divisions E2 and F1] A motor vehicle theft prevention device includes a bolt actuator 10, a slidable bolt 6, a compression spring 13 reacting between the bolt and the actuator, the bolt actuator being in the form of a flat plate and being slidable in one direction to retract the bolt and in the other direction to advance the bolt towards locking position, a plate-like cam 19 which is accommodated within an opening penetrating through the actuator and which is rotatable to effect sliding of the actuator by action of the cam against the edge of the opening. In the construction shown, the device is constructed for clamping on a steering column 15, the bolt being engageable with any of a number of sockets in the steering wheel shaft 18 to prevent rotation of the shaft; the cam is capable of some axial movement against the spring 20 before it can be rotated into the bolt advancing position, but for part of its possible rotational movement it rests upon a raised platform 22 which blocks such axial movement, the platform being part of a casing 1 having a key operable cylinder lock mechanism 23 in one end portion, the bolt actuator and the cam being accommodated in the casing underneath the cylinder lock mechanism, the lock cylinder 24 being arranged to turn a shaft 18 carrying the cam fixed to it. The cylinder lock mechanism is capable of inward axial sliding to effect the axial movement, against the spring 20, of the shaft carrying the cam. When the cam is resting on the raised platform 22, the cam is out of register with the end of a slot 9 in which the actuator 10 lies and the cam 19 cannot turn sufficiently to actuate the actuator since this rotational movement of the cam requires a part of it to enter the slot 9; however, if the cam is revolved sufficiently to clear the stop formed by the platform 22 the cam can be pushed axially against the compression spring 20 and this inward movement brings the cam 19 in register with the slot 9 and by holding the cam and shaft in this position the cam can be turned to move the actuator towards locking position. The platform 22 is part of a partition of the casing and on the opposite side of the partition to the cylinder lock mechanism 23 is an ignition and starter switch which is actuated by the bottom end portion of the shaft 18. The arrangement is such that starting from the " ignition-off " position of the lock cylinder 24 rotation of the cylinder by the key in clockwise direction is possible into ignition-on position and engine-starter operating position of the switch without the cam 19 moving the actuator 10 towards locking position. During this rotation of the cam the cam is resting on top of the raised platform 22 so that operation of the bolt to locking position cannot take place; in the ignition off position, however, and only in that position the cylinder lock mechanism can be pushed in so that the cam 19 clears the step formed by the platform to move the actuator 10; if the bolt cannot immediately enter one of the sockets in the steering wheel shaft the spring 13 is compressed. The shape of the cam and the opening in the actuator is such that in the locking position the cam secures the actuator and makes it impossible to rotate the cam by any force applied to the actuator.