Steering column and ignition lock for motor vehicle

Claim 1

In a lock arrangement for a motor vehicle having a steering column, which comprises (a) a housing defining an axial bore and a cross bore intersecting therewith, (b) a key controlled lock cylinder mounted in the axial bore of the housing for spring-biased axial displacement from an outwardly into an inwardly displaced position, and for rotation by the key about the axis of the bore in the inwardly displaced position into selected operating positions including a driving position, a ready-to-lock position and a locking position, (1) the lock cylinder having an axial keyhole for inserting the key in one axial direction and withdrawing the key in the opposite axial direction, (c) a lock bolt mounted in the cross bore for displacement from a retracted position into a locking position upon withdrawal of the key from the keyhole in the opposite axial direction, (1) the bolt having a keeper engaging a recess in the steering column in the locking position, (d) spring means engaging the lock bolt and biased to displace the lock bolt into the locking position, (1) the lock bolt cooperating with the lock cylinder to displace the lock cylinder into the outwardly displaced position during the displacement of the lock bolt into the locking position under the bias of the spring means (e) a latch member mounted on the lock bolt, and (f) actuating means arranged to displace the lock bolt between the retracted and locking positions, the bolt actuating means including (1) a driving member operated by the rotation of the lock cylinder to displace the bolt against the bias of the spring means into the retracted position to disengage the keeper from the steering column, the improvement of (g) the latch member being slidable in the direction of the axis and spring-biased into a position projecting from the bolt towards the lock cylinder, (h) the driving member including a control ring rotating and axially displaced with the lock cylinder, and eccentric cam means fixedly arranged eccentrically on the control ring, the cam means comprising a first cam cooperating with the latch member in the driving position of the lock cylinder for maintaining the lock bolt in the retracted position, a second arcuate cam having a periphery and an oblique camming face for engagement with the latch member and depressing the latch member against the spring bias during rotation of the lock cylinder from the locking into the driving position, the periphery of the second arcuate cam subtending the projecting latch member during rotation of the lock cylinder from the driving into the ready-to-lock position for maintaining the lock bolt in the retracted position, and a third cam projecting from the control ring towards the lock bolt and having an oblique camming face, and (i) a fourth cam fixed on the lock bolt, the fourth cam and the third cam being arranged to position the oblique camming face of the third cam in subtending engagement with the fourth cam in the ready-to-lock position whereby the lock bolt is temporarily prevented from displacement from the retracted into the locking position, the cams being dimensioned and shaped to enable the lock cylinder to be rotated into the selected operating positions and to maintain the lock bolt in the retracted position during the driving and ready-to-lock position of the lock cylinder.