GB2057555A

GB2057555A - Steering lock for motor vehicles

Info

Publication number: GB2057555A
Application number: GB8026868A
Authority: GB
Original assignee: Neiman SA
Current assignee: Valeo Neiman SA
Priority date: 1979-09-03
Filing date: 1980-08-18
Publication date: 1981-04-01
Also published as: DE2935556B1; FR2464166B1; IT8024427A0; IT1132627B; GB2057555B; FR2464166A1; ES253004U; ES253004Y; DE2935556C2

Abstract

The locking bolt assembly 26, 27, 28 of a steering-column lock is held retracted against spring 41 by an inclined sliding latch 35 which engages the rim of the bolt-lifting cam 29 until this is lifted clear by retraction of the barrel 3 when the key 4 is withdrawn.

Description

SPECIFICATION Steering lock for motor vehicles The invention relates to a steering lock for motor vehicles, comprising a lock bolt which can be engaged in the steering shaft and which can be withdrawn from the locking position to the nonlocking position by a switching barrel, which is coaxially secured to the cylinder core, against the pressure exerted by a spring and which, in the non-locking position, engages in a detented manner, by means of a part which is movably mounted in the lock bolt or in a lock bolt extension, through spring pressure behind a surface which is arranged so as to be oblique relative to the cylinder core axis so that the movably mounted part is disengaged and releases the lock bolt only after an axial displacement of the cylinder core and the switching barrel has been effected, which removes them from the lock bolt.

From DE OS 2 058 802 it is known to mount shaped parts in front of the keyhole opening and to associate with these radially adjoining control surfaces of an axially undisplaceable locking cylinder part so that, when the key is introduced, the cylinder core and the switching barrel coupled therewith are forcibly displaced against the spring action in the direction of the lock bolt. In conjunction with an adjoint swivel, on which a spring acts in the direction of the locking cylinder, in the lock bolt, this results in the ready-to-lock position, for the cancellation of which the cylinder core, including the switching barrel, has to be axially displaced by spring force in the retrograde sense after the withdrawal of the key.For this purpose, there is provided a compression spring which is supported on the axially undisplaceable locking cylinder parts and which is pre-tensioned by the cylinder core when the key is introduced.

The strength of this spring has to be adapted to the forces acting on the locking cylinder and lock parts during the frictional axial return movement.

In addition to the friction caused by the spring acting on the lock bolt, there also has to be considered the specific weight of the parts to be moved. In the case of large steering lock constructions which have a correspondingly strong compression spring, the forces arising during the introduction of the key have an unfavourable effect on the operation of the steering lock. In DE OS 2 309 867, there has therefore been proposed a steering lock construction in which there is provided for the retrograde axial displacement of the locking cylinder and lock parts an additional spring means which, without affecting the introduction of the key, is pre-tensioned appropriately by an elevated lock bolt cam at the locking cylinder end only when the rotation into the ready-to-lock position is effected.Due to the means required for this steering lock construction, this leads, in addition to the larger dimensions, to additional components and thus to a correspondingly expensive production.

From DE OS 27 57 544 it is known to bring about the ready-to-lock position by a springloaded pawl which is pivotally arranged on the lock bolt and which engages behind a projection of the switching barrel. In this known construction, the lock bolt has to be drawn into the lock housing beyond the ready-to-lock position in order to bring about the engagement of the pawl. Consequently, the cylinder core also has to be rotated by the key through a very large angle.

The present invention preferably improves a steering lock of the kind mentioned at the beginning in such a way that, while being of simple construction and requiring few components, it necessitates a short rotary path of the cylinder core and the switching barrel.

According to the present invantion, the part which is movably mounted in the lock bolt is a pin which is movable relative to the longitudinal axis thereof and whose longitudinal axis lies in a plane extending through the cylinder core axis and the lock bolt longitudinal axis or in a plane that is parallel thereto and is parallel to the zone of the oblique surface against which the pin bears in the various rotary positions of the switching barrel.

The solution according to the invention brings about an early engagement behind a switching barrel projection of the pin holding the lock bolt so that the rotary path of the cylinder core can be relatively short. Furthermore, the pin is mechanically highly loadable, is subjected to minimal wear and jams less easily than a locking swivel does. A high functional efficiency and operating reliability is also brought about in that, in contrast to a torsion spring, the pin may be loaded by a helical compression spring.

The loadability and operating reliability are increased in that the switching barrel comprises, at the end that is directed towards the lock bolt, a toroidal sector which, on the outside, has a frustoconical abutting surface for the pin and, on the inside, a second conical surface, whose inclination corresponds respectively in the zone of the pin to the inclination of the pin longitudinal axis and forms the oblique surface against which the pin bears in the non-locking position of the lock bolt.

A construction that can be produced in a particularly easy manner consists in that the pin is displaceable in an angular hole in the lock bolt or a lock bolt extension, in which hole there lies a compression spring. Furthermore, it is proposed that, in the zone where the torus is interrupted, the switching barrel should have a surface with which a pin which projects from the lock bolt or the lock bolt extension comes into abutting contact for the actuation of the lock bolt.

Advantageously, an additional spring-loading of the lock bolt tip at the steering end ensures that the function at the locking cylinder end required for the safety of the steering lock is also ensured when the lock bolt has not yet engaged in a locking slot in the steering shaft.

Due to the lock bolt subdivision resulting therefrom, it becomes possible to add to the highquality material of the lock bolt tip parts which, as regards the material and fabrication, can be produced at a far lower expenditure than comparable constructions of known steering locks.

An exemplified embodiment of the invention is shown in the drawings and will be described in more detail hereinafter. In the drawings FIGURE 1 shows a longitudinal section through the steering lock in the ready-to-lock position; FIGURE 2 shows a longitudinal section like that of Fig. 1 wherein the lock bolt has been partly displaced from the ready-to-lock position in the steering direction, with the key withdrawn; FIGURE 3 shows a longitudinal section like that of Fig. 1 in the locking position after the key has been withdrawn; and FIGURE 4 shows a cross section along the line I--I in Fig. 3.

The steering lock comprises a steering lock body 1 which receives the safety parts and which is secured to the vehicle part that is to be locked.

At the end that is accessible to the driver, the steering lock body is designed as a locking cylinder housing with a bore 2, in which a cylinder core 3 is mounted so as to be rotatable and axially displaceable, which core comprises lock tumblers 5 which are actuated by means of the key 4 and are acted on by springs and, for arresting the cylinder core 3 in the direction of rotation following the withdrawal of the key, project from the outer surface 6 of the cylinder core and are received by locking channels 7, 8 which are formed by radial widenings of the bore 2 which extend parallel to the cylinder axis.Forming a part of its axial extension, the cylinder core 3 comprises in the key introduction zone a lug 9, whose radial dimensions surmount the outer surface 6 of the cylinder core 3 at the lock bolt end and which, limiting the axial displacement path of the cylinder core 3 at the lock bolt end, comes into abutting contact with the front surface 11 of the steering lock body part 'la by means of a surface 10 extending all round.To limit the axial displacement of the cylinder core in the opposite direction, there is provided a cup-shaped steel part 12, which is mounted so as to be rotatable and secured against axial displacement in the direction of the lock front end 13, in a cap 14 which encloses the steering lock body part all round and which is connected to the steering lock body by frictionally and/or positively acting locking parts 15, 16 which prevent any unauthorised removal thereof. At the end that is adjacent to the cup bottom, the steel part 12 comes into abutting contact with the front surface 1 8 of the steering lock body part 1 a by means of an edge 17 formed by the cup opening.The inner cup zone 19 of the steel part adjoins the outer surface 20 of the cylinder core lug 9 all round and is positively connected to the cylinder core in the direction of rotation by a groove 21 which is open at the lock bolt end and into which there projects a noseshaped radial widening 22 of the lug 9. In accordance with the axial displacement path of the cylinder core 3 that is required for the function, a cavity 23 is provided in the steel part 12 between the inner cup bottom surface 1 2a and the front surface 9a of the lug 9. The cup bottom of the steel part has an opening 24 which corresponds to the peripheral dimensions of the key shank.In the lug 9, there are mounted so as to be radially movable slide-shaped control parts 25 which can be displaced by the key tip and which prevent the axial displacement of the cylinder core 3 required for the release of the spring-loaded lock bolt 26, 27, 28 until the key has been completely withdrawn from the lock.

In the lock bolt zone, the cylinder core 3 is positively connected so as to be secured against rotation by a clip connection to a coaxial switching barrel 29 which in a plane 29a that extends transversely (at right angles) to the cylinder axis comprises a control cam 30 with a control surface which acts on a cam 31, which is raised at the locking cylinder end, of the lock bolt for the displacement thereof into the unlocked position.

The control cam 30 or the switching barrel 29 respectively has at the end that is directed towards the lock bolt extension a semicircular coaxial bulge 34 which has a roof- or V-shaped cross section and which forms an outer frustoconical surface 33 and an inner conical surface 34, the two curved semicircular surfaces intersecting at approximately right angles in a part-ring-shaped ridge of the bulge 34. Together with a pin 35, which is axially movable in a bore in a lock bolt extension 26, this bulge 34 forms a form-locking mechanism, the pin being pressed to the outside by a spring 36 which lies in the bore.

Whilst the lock bolt is being drawn in, the pin comes into abutting contact with the surface 33 and is pressed by this latter into the bore until it engages behind the bulge and then, by means of its outer surface, comes into abutting contact with a section of the inner surface 34 of the bulge that is parallel to the pin axis.

There thus project, towards the locking cylinder end, diverging oblique surfaces of the bulge into the displacement path of the pin 35. With a fixedly or form-lockingly fitted shank 37 of smaller diameter, the locking cylinder core 3 penetrates a slot-shaped opening 38, which extends with the lock bolt longitudinal axis, in the lock bolt body or the lock bolt extension 26 respectively and, with a profiled end zone 39, engages in a form-locked manner in the rotatable part of the electric switch 40 of the steering lock.

The preferably multi-part lock bolt 26, 27, 28, which is displaceably mounted in the steering lock body 1, consists of the lock bolt extension 26, which is acted on by a spring 41, which is supported in the part 42, by means of which the lock bolt assembly hole in the steering lock body is closed. At the steering end, there is associated with the lock bolt extension 26, through a detent connection of known type, a connection piece 27 which consists of a flat material and is coupled with the locking steel part 28 of the lock bolt. With a portion 27a of its longitudinal extension, the connection piece 27 is displaceably mounted in a recess 28a in the steel part 28 and is acted on by a spring 43 which is supported in the steel part at 28b.Associated with the connection piece 27 is a slot-shaped opening 27b which extends with the longitudinal axis thereof and through which a bolt 44, which has been firmly pressed into the steel part, passes in such a way that the steel bolt 28 can be moved, in accordance with the slot length, in the retrograde sense into the steering lock body without affecting the lock bolt parts at the locking cylinder end.

To operate the steering lock, starting out from - the locking position shown in Fig. 4, the key 4 is introduced through the opening 24 in the steel part 12 into the keyhole 45 in the cylinder core 3 for the releasing integration of the lock tumblers 5.

During this process, the control parts 25 are radially displaced by the key shank andscome into abutting contact with a surface 47, which is formed in the steel part 12 by means of a radial widening 46, in such a way that a retrograde axial displacement of the cylinder core is prevented.

During the now following rotation of the key to the drive position, the control cam 30 of the switching barrel acts in known manner on the cam 31 of the lock bolt and moves this latter to the unlocked position. The locking part 35 in the lock bolt body 26 is pushed into the lock bolt body 26 by the oblique surface 33 of the coaxial partial zone 32 of the switching barrel 29 against the force in the spring 36 and, in the further course of the lock bolt displacement, is passed beneath the edge 48 formed by the oblique surfaces and, due to the action of the spring 36, enters the zone of the oblique surface 34 of the coaxial partial zone (Fig. 1). During this process, the electric unit 40 for controlling the working circuits of the vehicle is operated by parts at the cylinder core end.

To bring the steering lock into the holding or ready-to-lock position and subsequently to the locking position, the key is rotated in the opposite sense to the hold position, the ready-to-lock position; see Fig. 1. This causes the action of the control cam 29 of the switching barrel on the cam 31 of the lock to be cancelled. In the ready-to-lock position, the lock bolt is held in the unlocked position by the abutting contact of the locking part 35 with the oblique surface 34 of the coaxial partial zone 32. The longitudinal axis of the locking part 35 extends in this connection parallel to the oblique surface 34 of the partial zone. From the angular position to the lock bolt longitudinal axis there thus results, when the lock bolt spring 41 comes into action, a wedge surface effect which affects the cylinder core 3 in an axially retrograde sense.After the complete withdrawal of the key, the arrestment provided by the control parts is cancelled and the cylinder core, including the switching barrel, is displaced in the axial retrograde sense until the locking part 35, in the position in which it surmounts the lock bolt, can slide behind the edge 48 of the partial zone and the lock bolt can by this means be moved to the locking position by the action of the spring 41.

Once the locking position is reached, the cylinder core and the switching barrel return to their basic positions close to the lock bolt. In order to allow the basic positions shown in Figs. 4 and 5 to be reached, it is necessary for a single-part lock bolt to have penetrated into the locking slot in the locking sleeve provided on the steering shaft. If the lock bolt comes into abutting contact with the outer surface of the locking sleeve beside the locking slots, then the lock bolt parts in the locking cylinder zone have not reached their end positions and are in positions like those shown in Fig. 3. By this means, it is possible to move the lock bolt without the key to an unlocked position by exerting pressure on the cylinder core and to render the steering lock inoperative.

Due to the multi-part lock bolt construction according to the invention with the steel locking part, which is resiliently deflected, it is ensured in an advantageous manner that the lock bolt parts in the locking cylinder zone are always taken to positions that correspond to the locking position after the key has been withdrawn.

Claims

1. A steering lock for motor vehicles with a lock bolt which can be engaged in the steering shaft and which is withdrawable from the locking position to the non-locking position by a switching barrel, which is coaxially secured to the cylinder core, against the pressure exerted by a spring and which, in the non-locking position, engages in a detented manner, by means of a part which is movably mounted in the lock bolt or in a lock bolt extension, through spring pressure behind a surface which is arranged so as to be oblique relative to the cylinder core axis so that the movably mounted part is disengaged and releases the lock bolt only after an axial displacement of the cylinder core and the switching barrel has been effected, which removes them from the lock bolt, characterised in that the part which is movably mounted in the lock bolt is a pin which is movable relative to the longitudinal axis thereof and whose longitudinal axis lies in a plane that extends through the cylinder core axis and the lock bolt longitudinal axis or in a plane that is parallel thereto and is arranged so as to be parallel to the oblique surface zone against which the pin bears in the various rotary positions of the switching barrel.

2. A steering lock as claimed in Claim 1, characterised in that, at the end that is directed towards the lock bolt, the switching barrel comprises a toroidal sector which is coaxial with the cylinder core and which has, on the outside, a frusto-conical abutting surface for the pin and, on the inside, a second conical surface, whose inclination in the respective zone of the pin (35) corresponds to the inclination of the pin longitudinal axis and forms the oblique surface against which the pin bears in the non-locking position of the lock bolt.

3. A steering lock as claimed in Claim 1 or 2, characterised in that the pin is displaceable in an angular hole in the lock bolt or a lock bolt extension, in which hole there lies a compression spring.

4. A steering lock as claimed in one of Claims 1 to 3, characterised in that in the zone in which the bulge is interrupted, the switching barrel has a surface with which a pin, which projects from the lock bolt or the lock bolt extension, comes into abutting contact for the operation of the lock bolt.

5. A steering lock as claimed in one of Claims 1 to 4, characterised in that the lock bolt comprises a front part, which locks the steering column, and a part which carries the pin, both parts being displaceable relative to each other in a limited manner and being removable from each other by a spring.

6. A steering lock for motor vehicles substantially as described herein with reference to the accompanying drawings.