GB2350827A

GB2350827A - Motor vehicle steering lock

Info

Publication number: GB2350827A
Application number: GB0013846A
Authority: GB
Inventors: Hans-Joachim Limburg; Friedrich Pieper
Original assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Current assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Priority date: 1999-06-08
Filing date: 2000-06-08
Publication date: 2000-12-13
Anticipated expiration: 2020-06-08
Also published as: GB0013846D0; DE29909966U1; GB2350827B

Abstract

A motor vehicle steering lock is secured on a hollow outer steering column (3) enclosing the steering shaft (2) of the vehicle by means of a yoke (10) engaging around the steering column (3) on the side remote from the steering lock housing (5). The yoke (10) is screwed to the steering lock housing (5) on both sides of the steering column (3) by a respective break-off screw (18, 19). Each break-off screw (18,19) is secured against being unscrewed out of its threaded bore (22, 23) by a security pin (28, 29). Each security pin is inserted in a respective bore (30, 31) in the steering lock housing (5) running perpendicular to the threaded bore (22, 23) and intersecting the threaded bore (22, 23) tangentially, in order to extend tangentially through a respective annular groove (34, 35) in the break-off screw (18, 19). Each security pin (22, 23) has its inner end (36, 37) engaging in a bore (32, 33) in the steering column (3).

Description

2350827 MOTOR VEHICLE STEERING LOCK The invention relates to a motor

vehicle steering lock of the kind attached to. the hollow outer steering column surrounding the steering shaft of the vehicle by means of a yoke which engages the steering column on the side remote from the steering lock housing and is screwed to the steering lock housing by a respective break-off screw on each side of the steering column.

Such motor vehicle steering locks are known (DE 27 39 393 C2). In these steering locks the break-off screws are intended to prevent or at least make difficult the removal of the attachment yoke from the steering lock housing. For this purpose the break-off screws have in addition to the actual attachment head a separate head which allows the screw to be tightened and then is sheared off after tightening so that the screw in question cannot thereafter be undone using a spanner or the like.

It is also known, for screwing the attachment yoke to the steering lock housing, to use instead of break-off screws two one-way screws which only allow rotation in a tightening direction and of which the heads are received in two recesses in the attachment yoke, into which two closure plugs are then pressed, of which the outer faces are subsequently finished so that they lie flush with the external surface of the attachment yoke and form a single surface (US 1 592 091).

The invention is based on solving ihe problem of providing a motor vehicle steering lock of the kind set forth, of which the attachment to the steering column of the vehicle is still more secure and is still achieved if it proves possible to release the break-off screws and to remove the attachment yoke from the steering lock housing.

According to the present invention, in a motor vehicle steering lock of the kind set forth, each break-off screw is secured against unscrewing from a threaded bore in the steering lock housing by a security pin, each security pin being inserted in an associated bore in the steering lock housing perpendicular to the threaded bore and intersecting the threaded bore tangentially, in order to extend tangentially through an annular groove in the break-off screw, and having an inner end engaging in a bore in the steering column.

The security pins provided according to the invention make it virtually impossible to unscrew the break-off screws from their threaded bores in the steering lock housing, for example using a hammer and a punch applied to the externally smooth attachment head of the respective break- off screw engaging over the attachment yoke. Furthermore the security pins hold the steering lock housing on the steering column of the respective vehicle even if in some manner it is possible to succeed in unscrewing the break-off screws out of the steering lock housing and removing the attachment yoke from the housing, so that the vehicle steering lock remains attached to the respective steering column even in this situation.

Preferably each security pin is arranged with a press fit in the associated bore in the steering lock housing, to ensure they are securely fitted. Each security pin may have a head of enlarged diameter received in a counterbore of the associated bore in the steering lock housing.

Conveniently the longitudinal axes of the two threaded bores which receive the break-off screws and the longitudinal axes of the two bores in the steering lock housing which receive the security pins extend in 3 respective common planes perpendicular to the longitudinal axis of the steering column. The longitudinal axes of the two sets---of bores preferably are parallel, perpendicular to a plane dividing the steering lock housing and the yoke and coincident with a straight line parallel to the 5 dividing plane.

Preferably the yoke is provided with two recesses for receiving the attachment heads of the break-off screws. The yoke may be a sheet metal pressing.

An embodiment of the motor vehicle steering lock according to the invention is illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a cross-section on the line I-I in Figure 2 through the motor vehicle steering column assembly provided with the steering lock; and Figure 2 is a longitudinal section on the line II-II in Figure 1 through the motor vehicle steering column assembly provided with the steering lock.

The steering column assembly 1 of a motor vehicle which is illustrated comprises a steering shaft 2 connecting the steering wheel to the steering mechanism of the vehicle and a hollow outer steering column 3 which surrounds the rotatable shaft 2 and is attached to the bodywork of the vehicle. The steering column assembly 1 is provided with a steering lock 4 which has a housing 5 and a locking bolt 6 for locking the shaft 2 against rotation. The bolt 6 is displaceable axially in the housing 5 of the C.

steering lock and co-operates through an opening 7 in the column 3 with a 4 locking sleeve 8 attached to the shaft 2 and provided with locking openings 9 for receiving the tip of the locking bolt 6.

The steering lock 4 is attached to the column 3 by means of a yoke 10.

The attachment yoke 10 engages around the column 3 on the side remote from the steering lock housing 5 with an arcuate central portion 11 of which the radius of curvature matches the radius of the column 3 and which joins together two flange-like end portions 12, 13. The attachment yoke 10 extends transversely across the steering column 3 and is screwed to the steering lock housing 5 on the left hand side in Figures 1, 2 and the right hand side in Figures 1, 2 of the steering column 3. The housing 5 has an arcuate flange 14 which engages the column 3 and has a radius of curvature matching the radius of the column 3 and from which two plate shaped lateral projections 15, 16 project. The attachment yoke 10 and the steering lock housing 5 enclose the steering column 3 with a clamp fit, and a collar 17 of the steering lock housing 5 engages in the opening 7 around the locking bolt 6.

The attachment yoke 10 is screwed to the steering lock housing 5 by two break-off screws 18, 19. Each screw passes through a respective bore 20 or 21 in a respective end portion 12 or 13 of the yoke 10 and is screwed into a respective screw-threaded bore 22 or 23 in the respective lateral projection 15 or 16 of the flange 14 of the steering lock housing 5. The screws 18, 19 have respective externally smooth attachment heads 24, 25, which press the associated end portion 12 or 13 of the attachment yoke 10 against the associated lateral projection 15 and 16 of the steering lock housing flange 14. In order to make access more difficult, the attachment heads 24, 25 of the break-off screws 18, 19 are each received in a respective recess 26 or 27 in the associated end portion 12 or 13 of the attachment yoke 10, which is in the form of a sheet metal pressing.

The two break-off screws 18, 19 are each secured by a respective security pin 28 or 29 against unscrewing from the respective threaded bore 22 or 23 in the associated lateral projection 15 or 16 of the steering lock housing flange 14. Each security pin 28 or 29 is received in a respective bore 30 or 31 in a respective lateral projection 15 or 16 of the steering lock housing flange 14 with a press fit. The bore 30, 31 extends perpendicular to the respective threaded bore 22 or 23 in the lateral projection 15 or 16 and intersects the threaded bore 22 or 23 tangentially.

Each bore 30, 31 is aligned with a respective bore 32 or 33 in the steering column 3 so that each security pin 28 or 29 extends tangentially through a respective annular groove 34 or 35 in the associated break-off screw 18 or 19 and has its inner end 36 or 37 engaging in the associated bore 32 or 33 in the steering column 3. By the engagement of the security pins 28, 29 in the annular grooves 34, 35 in the break-off screws 18, 19 the unscrewing of the latter from their threaded bores 22, 23 is prevented and the engagement of the security pins 28, 29 in the bores 32, 33 in the steering column 3 ensures that the steering lock housing 5 remains attached to the steering column 3 even after removal of the attachment yoke 10.

The two security pins 28, 29 are hammered into the respective receiving bore 30 or 31 and are each provided with a head 38 or 39 of larger diameter which is received in a counterbore 40 or 41 of the receiving bore 30 or 31. The heads 38, 39 prevent the security pins 28, 29 being hammered in too far.

The longitudinal axes 42, 43 of the two threaded bores 22, 23 in the lateral projections 15, 16 of the steering lock housing flange 14 extend in a common first plane 45 perpendicular to the longitudinal axis 44 of the 6 steering column 3 and in fact parallel to one another perpendicular to a dividing plane 46 between the steering lock housing 5 and the attachment yoke 10. The longitudinal axes 47, 48 of the two additional bores 30, 31 in the lateral projections 15, 16 of the steering lock housing flange 14 5 extend in a common second plane 49 perpendicular to the longitudinal axis 44 of the steering column 3, and they coincide with a straight line 50 running parallel to the dividing plane 46 between the steering lock housing 5 and the attachment yoke 10.

Claims

7 CLAIMS

1 A motor vehicle steering lock of the kind set forth, in which each break-off screw is secured against unscrewing from a threaded bore in the steering lock housing by a security pin, each security pin being inserted in an associated bore in the steering lock housing perpendicular to the threaded bore and intersecting the threaded bore tangentially, in order to extend tangentially through an annular groove in the break-off screw, and having an inner end engaging in a bore in the steering column.

2. A steering lock as claimed in claim 1, in which each security pin is arranged with a press fit in the associated bore in the steering lock housing.

3. A steering lock as claimed in claim 1 or claim 2, in which each security pin has a head of enlarged diameter received in a counterbore of the associated bore in the steering lock housing.

4. A steering lock as claimed in any preceding claim, in which the longitudinal axes of the two threaded bores which receive the break-off screws and the longitudinal axes of the two bores in the steering lock housing which receive the security pins extend in respective common planes extending perpendicular to the 25 longitudinal axis of the steering column. 5. A steering lock as claimed in claim 4, in which the longitudinal axes of the two threaded bores which receive the break-off screws and the longitudinal axes of the two bores in the 30 steering lock housing which receive the security pins extend 8 parallel, perpendicular to a plane dividing the steering lock housing and the yoke and coinciding with a straight line parallel to the dividing plane.

6. A steering lock as claimed in any preceding claim, in which the yoke is provided with two recesses for receiving the attachment heads of the break-off screws. 7. A steering lock as claimed in any preceding claim, in which 10 the yoke is a sheet metal pressing.

8. A motor vehicle steering lock of the kind set forth substantially as described herein with reference to and as illustrated in the accompanying drawings.