GB1560899A

GB1560899A - Steering and ignition lock

Info

Publication number: GB1560899A
Application number: GB4577576A
Authority: GB
Original assignee: Ymos Metallwerke Wolf and Becker GmbH and Co
Current assignee: Ymos Metallwerke Wolf and Becker GmbH and Co
Priority date: 1975-11-06
Filing date: 1976-11-03
Publication date: 1980-02-13
Also published as: FR2330570A1; SE7612126L; DE2549774A1; DE2549774C2

Description

(54) STEERING AND IGNITION LOCK (71) We, YMOS METALLWERKE WOLF AND BECKER GMBH & CO., a Germany Company, of Feldstrasse 12, D-6055 Hausen, Krs., Offenbachon-Main, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly de scribes in and by the following statement:- This invention relates to a steering and ignition lock, particularly for motor vehicles, and having a lock cylinder which is biased by a compression spring and is axially displaceable thereby in the steering lock housmg and which controls a locking pin by way of a cam carrier.

Steering and ignition locks of this kind have been known for many years and are used in a wide variety of forms. Although the locking cylinder and its tumblers are intended ito provide the greatest possible protection as regards unauthorized use of the vehicle, it has been found that the locking cylinder can be forced out of the bush containing it i.e. out of the steering lock housing. If this is done, then in the known steering and ignition locks, there is no difficulty in releasing the steering of the vehicle and turning on the ignition.

According to the invention there is provided a steering and ignition lock having a lock cylinder axially displaceable in the housing, and which is spring biassed in one direction of movement and is detachably connected to a cam carrier which carries an eccentric cam for operating a locking pin upon rotation of the lock cylinder within the housing, wherein the cam carrier has a shoulder on its periphery which is engageable with a stop pin in the housing, and a recess to receive a spring loaded bolt when the cam carrier is axially moved by the biassing spring upon the extrac;tion of the lock cylinder from the housing, whereby removal of the cam carrier from the housing is prevented.

Since the locking cylinder and the cam carrier are detachably connected to each other, the locking pin which engages in the steering column is still not readily accessible after the locking cylinder has been removed. It can therefore be of such shape that, upon removal of the locking cylinder, it moves into a fully blocking position which makes it impossible for the vehicle to be started.

The invention will now be described in greater detail by reference to an embodiment illustrated in the accompanying drawings, wherein: Figure 1 is a section through a steering and ignition lock according to the invention in a blocking position; Figure 2 is a section on the line II-II of Figure 1; Figure 3 is a sectional view similar to that of Fig. 1 showing the blocking position prior to removal of the key; Figure 4 illustrates a detail on a larger scale; Figure 5 is a sectional view as in Fig. 1 but turned through 90 ; Figure 6 is a sectional view of part of the arrangement shown in Fig. 5, with the pin engaged in the cam carrier; and Figure 7 is a sectional view along the line VIll-VllI of Fig. 1.

The steering and ignition lock comprises a locking cylinder 2 which is biassed by a compression spring 3 and is axially displaceable in a closure cap 4 and bush 5 and which controls a locking pin 7 by way of a cam carrier 6. For this purpose the cam carrier 6 has an eccentric cam 8 (Fig. 7) which, when locking cylinder 2 is rotated, moves towards a stop plate 10, which is biased by at least one spring 9 and is connected in the customary manner bo the locking pin 7.

Near the inlet opening, the locking cylinder 2 has a transverse slide 11; the end of this slide that projects from the locking cylinder 2 engages in a part-cylindrical part-conical annular recess 12 in the closure cap 4. With the aid of the transverse slide 11, the locking cylinder 2 can spring back into the blocking position upon removal of the key only when the tip of the key has been almost completely withdrawn from the key passage 13.

The cam carrier 6 is detachably connected to the locking cylinder 2. For this purpose and as shown in Fig. 2, use is made of two pins 14 and 15 which extend axially from the locking cylinder 2 into the cam carrier 6. If the locking cylinder 2 is forced out of the bush 5, then the locking cylinder 2 and the cam carrier 6 become separated, the cam carrier 6 remaining in a recess 16 in the steering lock housing 17 in which it is housed. This is accomplished (as shown in Figure 5) with the aid of a shoulder 18 and a recess 19 formed in the periphery 20 of the cam carrier 6, and with the help of a stop pin 21 and a bolt 23 biased by a spring 22, the stop pin and the bolt being arranged in the steering lock housing 17. As soon as the cam carrier 6 is displaced slightly in the axial direction after removal of the locking cylinder 2, the shoulder 18 encounters the stop pin 21, and at the same time the springloaded bolt 23 moves into its associated recess 19 and completely blocks the cam carrier 6.

Axial displacement of the cam carrier 6 is achieved with aid of the compression spring 3 which engages the axially extending shank 31 of the cam carrier and lifts it until the shoulder 18 encounters the stop pin 21.

In order to ensure that the steering and ignition lock 1 functions efficiently, a slide element 26 is displaceable on the cam carrier 6 in the axial direction of the locking cylinder 2 and is guided by a dovetail groove 27.

The slide element 26 is biased by a compression spring 24 which is supported at one end on a disc-like part 25 of the cam carrier 6, and at the other end on the slide element 26.

As will be seen in Fig. 1, the slide element 26 bears against the stop plate 10, when the steering and ignition lock is in the blocking position, and has a control lug 28 which faces the stop plate 10. Finally, an axially extending slot 26a is formed in the slide element 26, and a pin 26b projects from the cam carrier 6 into this slot. On that of its faces presented to the slide element 26, the stop plate 10 has a pocket 29, at the side of which is located a backing element 30 for the slide element 26.

As soon as the locking cylinder 2 is axially displaced in the steering lock housing 17 upon introduction of the key into the key passage 13, this movement is also transknitted to the cam carrier 6 and its shank 31, the compression springs 3 and 24 being thereby stressed. During the following rotary movement of the locking cylinder 2 into the operating positions "start up" and "go", the cam carrier 6 also rotates on account of the inter-locking connection by way of the pins 14 and 15, and as it does so pulls the locking pin 7 out of the locking positions as a result of contact with the stop plate 10. The stop plate 10 is moved by The eccentric cam 8 until the entire periphery 20 of the cam carrier 6 takes over the retaining function opposite the stop plate 10 and maintains this function until the "start up" end position is reached.

During this rotary movement of the cam carrier 6, the slide element 26 executes a limited stroke in the direction of the locking pin 7. For this it is important that, at the start of the movement of the locking pin 7 and the stop plate 10, the control lug 28 on the slide element 26 is able to swing past the backing element 30 of the stop plate 10.

For this purpose the pocket 29 has a recess 32 through which the control lug 28 can emerge from the pocket 29 as shown in Figure 7.

When the cam carrier 6 is rotated into the "go" position, the control lug 28 swings out of the pocket 29. The slide element 27 is then caused by the compression spring 24 to move rapidly in front of the stop plate 10 as will be seen from Figure 3, The slide element 26 remains in this position until the locking cylinder 2, after removal of the key 3, has returned to the blocking position shown in Figure 5, so that ithe cam carrier 6 and the slide element 26, which is held by the pin 26b, will also have changed their axial positions to such an extent that the control lug 28 on the slide element 26 can have deflected over the backing element 30 because of the elasticity of the compression spring 24. To enable this movement to take place in an efficient manner, both the control lug 28 and the backing element 30 have bevelled surfaces which face each other in the position shown in Figure 3.

WHAT WE CLAIM IS: 1. A steering and ignition locking having a lock cylinder axially displaceable in a housing, and which is spring biassed in one direction of movement and is detachably connected to a cam carrier which carries an eccentric cam for operating a locking pin upon rotation of the lock cylinder within the housing, wherein the cam carrier has a shoulder on its periphery which is engageable with a stop pin in the housing, and a recess to receive a spring loaded bolt when the cam carrier is axially moved by the biassing spring upon extraction of the lock cylinder from the housing, whereby removal of the cam carrier from the housing is prevented.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of this slide that projects from the locking cylinder 2 engages in a part-cylindrical part-conical annular recess 12 in the closure cap 4. With the aid of the transverse slide 11, the locking cylinder 2 can spring back into the blocking position upon removal of the key only when the tip of the key has been almost completely withdrawn from the key passage 13. The cam carrier 6 is detachably connected to the locking cylinder 2. For this purpose and as shown in Fig. 2, use is made of two pins 14 and 15 which extend axially from the locking cylinder 2 into the cam carrier 6. If the locking cylinder 2 is forced out of the bush 5, then the locking cylinder 2 and the cam carrier 6 become separated, the cam carrier 6 remaining in a recess 16 in the steering lock housing 17 in which it is housed. This is accomplished (as shown in Figure 5) with the aid of a shoulder 18 and a recess 19 formed in the periphery 20 of the cam carrier 6, and with the help of a stop pin 21 and a bolt 23 biased by a spring 22, the stop pin and the bolt being arranged in the steering lock housing 17. As soon as the cam carrier 6 is displaced slightly in the axial direction after removal of the locking cylinder 2, the shoulder 18 encounters the stop pin 21, and at the same time the springloaded bolt 23 moves into its associated recess 19 and completely blocks the cam carrier 6. Axial displacement of the cam carrier 6 is achieved with aid of the compression spring 3 which engages the axially extending shank 31 of the cam carrier and lifts it until the shoulder 18 encounters the stop pin 21. In order to ensure that the steering and ignition lock 1 functions efficiently, a slide element 26 is displaceable on the cam carrier 6 in the axial direction of the locking cylinder 2 and is guided by a dovetail groove 27. The slide element 26 is biased by a compression spring 24 which is supported at one end on a disc-like part 25 of the cam carrier 6, and at the other end on the slide element 26. As will be seen in Fig. 1, the slide element 26 bears against the stop plate 10, when the steering and ignition lock is in the blocking position, and has a control lug 28 which faces the stop plate 10. Finally, an axially extending slot 26a is formed in the slide element 26, and a pin 26b projects from the cam carrier 6 into this slot. On that of its faces presented to the slide element 26, the stop plate 10 has a pocket 29, at the side of which is located a backing element 30 for the slide element 26. As soon as the locking cylinder 2 is axially displaced in the steering lock housing 17 upon introduction of the key into the key passage 13, this movement is also transknitted to the cam carrier 6 and its shank 31, the compression springs 3 and 24 being thereby stressed. During the following rotary movement of the locking cylinder 2 into the operating positions "start up" and "go", the cam carrier 6 also rotates on account of the inter-locking connection by way of the pins 14 and 15, and as it does so pulls the locking pin 7 out of the locking positions as a result of contact with the stop plate 10. The stop plate 10 is moved by The eccentric cam 8 until the entire periphery 20 of the cam carrier 6 takes over the retaining function opposite the stop plate 10 and maintains this function until the "start up" end position is reached. During this rotary movement of the cam carrier 6, the slide element 26 executes a limited stroke in the direction of the locking pin 7. For this it is important that, at the start of the movement of the locking pin 7 and the stop plate 10, the control lug 28 on the slide element 26 is able to swing past the backing element 30 of the stop plate 10. For this purpose the pocket 29 has a recess 32 through which the control lug 28 can emerge from the pocket 29 as shown in Figure 7. When the cam carrier 6 is rotated into the "go" position, the control lug 28 swings out of the pocket 29. The slide element 27 is then caused by the compression spring 24 to move rapidly in front of the stop plate 10 as will be seen from Figure 3, The slide element 26 remains in this position until the locking cylinder 2, after removal of the key 3, has returned to the blocking position shown in Figure 5, so that ithe cam carrier 6 and the slide element 26, which is held by the pin 26b, will also have changed their axial positions to such an extent that the control lug 28 on the slide element 26 can have deflected over the backing element 30 because of the elasticity of the compression spring 24. To enable this movement to take place in an efficient manner, both the control lug 28 and the backing element 30 have bevelled surfaces which face each other in the position shown in Figure 3. WHAT WE CLAIM IS:

1. A steering and ignition locking having a lock cylinder axially displaceable in a housing, and which is spring biassed in one direction of movement and is detachably connected to a cam carrier which carries an eccentric cam for operating a locking pin upon rotation of the lock cylinder within the housing, wherein the cam carrier has a shoulder on its periphery which is engageable with a stop pin in the housing, and a recess to receive a spring loaded bolt when the cam carrier is axially moved by the biassing spring upon extraction of the lock cylinder from the housing, whereby removal of the cam carrier from the housing is prevented.

2. A steering and ignition lock according

to claim 1, wherein the locking pin is connected to a stop plate, and the cam carrier has a slide element mounted thereon which is moveable by a further biassing spring into engagement with the stop plate.

3. A steering and ignition lock according to claim 2 wherein the stop plate has a backing element to engage the slide element and a pocket to receive a control lug on the slide element when the locking pin and ithe stop plate are in the locked position.

4. A steering and ignition lock according to any of the preceding claims, wherein the lock cylinder is connected to the cam carrier by two pins projecting from the lock cylinder.

5. A steering and ignition lock constructed and arranged substantially as hereinbefore described and shown in the accompanying drawings.