Steering Lock

1. Field of the Invention

The present invention relates to a steering lock for locking a steering shaft of an associated motor vehicle. The lock is generally of the type comprising a rotatable lock cylinder, a latch operable in one position and inoperable in a second position to engage a recess in the steering shaft of the vehicle and a rocking lever operable in one position and inoperable in a second position to maintain the latch in its second position.

2. Description of the Prior Art

Steering locks of the general type described above are known in the prior art, being shown, for example, in British Pat. No. 1,263,362, British Patent Application No. 2,042,621 and German (Federal Republic) Patent Application No. 1,800,882. Each of these references discloses a steering lock including a rotatable lock cylinder, a rocking lever and means mounting the rocking lever for rotation and sliding movement in a plane which intersects the axis of rotation of the lock cylinder.

The instant invention is based upon the discovery of an improvement in a steering lock of the type comprising a rotatable lock cylinder, a latch operable in a first position and inoperable in a second position to engage a recess in a steering shaft of an associated motor vehicle, and a rocking lever operable in a first position and inoperable in a second position to maintain the latch in its second position. During rotation of the lock cylinder in one direction, the latch is caused to move from its first position towards its second position. When the latch reaches its second position, a projection on the rocking lever engages a recess in the latch whereby it is maintained in its second position and the steering shaft is maintained in an unlocked condition.

According to the improvement of the instant invention, the steering lock includes means mounting the rocking lever for rotation in two different planes. The rocking lever is mounted for rotation in a first plane about an axle and, in a second plane, about one of its ends. The latch causes rotation of the rocking lever in the second plane in one direction as it moves towards its second position, while a spring causes rotation thereof in the other direction when the latch reaches its second position. As a result of the rotation caused by the spring, the projection on the rocking lever is caused to engage the recess in the latch.

According to a further improvement of the instant invention, a part which rotates with the lock cylinder is provided with a radially extending wall. In a manner more fully described below, the wall supplements the spring to ensure rotation of the rocking lever and the consequential engagement between the projection of the rocking lever and the recess of the latch when it is in its second position.

Accordingly, it is an object of the instant invention to provide an improved steering lock.

It is a further object to provide a steering lock wherein the latch is maintained, at all appropriate times, in a position where it does not engage the steering shaft.

Other objects and advantages of the invention will be apparent from the description which follows, reference being made to the accompanying drawings.

FIG. 1 is a view in longitudinal cross-section of a steering lock according to the instant invention showing a lock cylinder in a first position, a latch in a corresponding first position, and a rocking lever in a position to which it is forced when a key is inserted in an associated lock cylinder.

FIG. 2 is a partial view of the top of the steering lock of FIG. 1.

FIG. 3 is a partial side view of the steering lock as viewed from the direction of an arrow 3 of FIG. 1.

FIG. 4 is a view of the top of the steering lock showing the lock cylinder in the first position when the cylinder is in this position, insertion of a key in the lock cylinder moves the latch and the rocking lever to the positions shown in FIG. 1.

FIG. 5 is a view similar to FIG. 1, showing the lock cylinder in its first position, the latch in its first position, and the locking lever in a position to which it is forced when a key is removed from the associated lock cylinder.

FIG. 6 is a view of the top of the steering lock showing the lock cylinder in the first position when the cylinder is in this position, removal of the key from the lock cylinder causes the rocking lever to move to the position shown in FIG. 5.

FIG. 7 is a view similar to FIG. 3, showing the lock cylinder in a position intermediate between the first position and a second position, the latch in a corresponding intermediate position, and the rocking lever in a position to which it is forced when the latch is moved to the intermediate position.

FIG. 8 is a view of the top of the steering lock showing the lock cylinder in an intermediate position. Rotation of the lock cylinder to the intermediate position of FIG. 8 moves the latch and the rocking lever to the intermediate positions shown in FIG. 7.

FIG. 9 is a view similar to FIG. 3 showing the lock cylinder in the second position, the latch in a corresponding second position, and the rocking lever in a position to which it is forced when the latch and the locking cylinder are moved to their second positions from their first positions.

FIG. 10 is a view of the top of the steering lock showing the lock cylinder in the second position. Rotation of the lock cylinder to the position of FIG. 10 moves the latch to the position of FIG. 9, whereupon a spring moves the rocking lever to the position shown in FIG. 9.

FIG. 11 is a view similar to FIG. 1 showing the lock cylinder in a third position, the latch in the second position, and the rocking lever in a position to which it is forced when the latch and the locking cylinder are moved to their second positions.

FIG. 12 is a view of the top of the steering lock showing the lock cylinder in the third position. Rotation of the lock cylinder from its second position to its third position does not effect a corresponding change in the positions of the latch and the rocking lever.

FIG. 13 is a view similar to FIG. 1 showing the lock cylinder in the first position, the latch in the second position, and the rocking lever in a position to which it is forced when the latch and the locking cylinder are moved from their first positions to their second positions.

FIG. 14 is a view of the top of the steering lock showing the lock cylinder in the first position. Rotation of the lock cylinder form the first position to a fourth position, which is indicated by dotted lines, does not effect a corresponding change in the positions of the latch and the rocking lever.

A steering lock according to the improvement of the invention, as shown in FIGS. 1-3, comprises an exterior housing 1, a key-actuated rotatable lock cylinder 2 with a key-slot 2-a (FIG. 2), a latch 3, rotatable parts 4 and 5 which are integral with the rotatable lock cylinder 2, a stationary part 6 and a collar 7 for attaching the steering lock to a steering column (not shown) of a vehicle (not shown). The steering lock as shown in FIGS. 1, 2 and 3, includes an electrical switch 8 with a detent 8-a. The switch 8 is actuated during rotation of the lock cylinder 2 by a cam 5-b which acts on the detent 8-a; the switch 8 may control various circuits in the electrical system of the vehicle. The steering lock further comprises a rocking lever 9 which is mounted for rotation about an axle 10, a spring 10-a (FIG. 3) which is mounted about the axle 10, a sliding cam 11 which is mounted in a radially extending slot in the lock cylinder 2 for sliding movement therein and a spring 12 mounted between the stationary part 6 and the latch 3.

The embodiment of the steering lock of the invention shown in the drawings has four operating positions which correspond with four angular positions of the key-slot 2-a, and of an ignition key (not shown) therein. In FIGS. 4, 6, 8, 10, 12 and 14, A, B, C and D indicate angular positions of the key-slot 2-a corresponding, respectively, with the "stop", "running", "starting" and "parking" positions of the ignition key in the steering lock. The operation of the preferred embodiment of the improved steering lock will be described now with reference to FIGS. 1, 3, 5, 7, 9, 11 and 13, the corresponding angular positions of the key-slot 2-a being shown in FIGS. 2, 4, 6, 8, 10, 12 and 14, respectively.

When the ignition key has been turned to the stop position A and withdrawn from the key-slot 2-a (FIG. 5), the latch 3 is in its first position wherein it is operable to engage a steering shaft recess (not shown). A projection 9-a on the rocking lever 9 extends into a radial slot in the rotatable lock cylinder 2. When the ignition key (not shown) is inserted in the key-slot 2-a (FIG. 1), the sliding cam 11 and the projection 9-a are caused to move radially outwardly in the slot in the lock cylinder 2. Accordingly, the rocking lever 9 pivots about the axle 10, in a plane which intersects the axis of rotation of the lock cylinder 2. As the ignition key is turned from the stop position A toward the starting position C, a helical cam 5-a acts on a detent 3-a causing the latch 3 to move upwardly from its first position (FIG. 1) towards its second position (FIG. 11). During this movement of the latch 3, an inclined surface 3-c thereof urges an end 9-e of the lever 9 (FIGS. 3, 7 and 9) to the right, causing the lever 9 to rotate about its end 9-d which rests against a radial wall 1-a of the housing 1. It will be noted that this rotation is in a plane which does not intersect the axis of rotation of the lock cylinder 2. As shown in FIG. 7, during this rotation, the spring 10-a is compressed by the rocking lever 9. There is limited clearance between the rocking lever 9 and the axle 10 to accommodate this rotation.

When the ignition key reaches its "running" position (FIGS. 9 and 10), the latch 3 reaches its second position. At this point, a recess 3-b in the latch 3 is adjacent a stop 9-b (FIGS. 1, 5, 11 and 13) of the rocking lever 9; as a consequence, the spring 10-a forces the end 9e of the latter to the left (FIG. 9), moving the stop 9-b into the recess 3-b, so that the rocking lever 9 prevents the latch 3 from moving downwardly from its second position acting against the spring 12.

When the ignition key is turned from the "running" position B (FIG. 9) towards either the "stop" position A (FIG. 3) or the "starting" position C (FIG. 11), the relative positions of the latch 3 and the rocking lever 9 remain the same; the lock cylinder 2 rotates and the projection 9-a slides on the exterior of the lock cylinder 2 and the sliding plate 11.

When the ignition key is turned to the "stop" position A (FIG. 1) and is withdrawn from the key-slot 2-a, the rocking lever 9 rotates about the axle 10 and the projection 9-a moves the sliding cam 11 radially inwardly of the lock cylinder 2 (FIG. 5). The rotation of the rocking lever 9 is caused by the spring 12, acting on the latch 3, and transmits through a wall adjacent the recess 3-b and a portion of the stop 9-b. When the rocking lever 9 rotates to its first position (FIG. 5), the stop 9-b is moved out of the recess 3-b whereupon the spring 12 moves the latch 3 to its first position.

As shown in FIG. 11, the rotating part 4 has a radially extending wall 4-a which is positioned so that it contacts the projection 9-c of the rocking lever 9 when the stop 9-b is engaged in the recess 3-b. If the locking cylinder 2 is rotated from the running position B towards the starting position C, the wall 4-a, acting on the projection 9-C, causes the rocking lever 9 to rotate from the position shown in FIG. 7 to the position shown in FIG. 9. Thus, the wall 4-a compliments the spring 10-a to ensure that the rocking lever 9 will rotate and that the projection 9-b will engage the recess 3-b to maintain the latch 3 in its second position wherein the steering shaft is unlocked when the associated vehicle is started.

Although a preferred embodiment has been described, it is to be understood that the scope of the invention is not limited thereto or thereby. It will be apparent that various changes and modifications can be made from the specific details of the invention as disclosed herein without departing from the spirit and scope thereof as defined in the following claims.