Machine element or mechanism – Control lever and linkage systems – Hand operated
Reexamination Certificate
2000-02-07
2001-05-22
Bucci, David A. (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Hand operated
C074S531000, C070S184000, C180S287000, C192S070230
Reexamination Certificate
active
06234039
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to antitheft devices in the form of a steering lock for a motor vehicle steering column.
BACKGROUND OF THE INVENTION
Known types of steering locks usually make use of a retractable lock bolt for the purpose of preventing any rotation of the shaft of the steering column. This bolt is carried by a structural element of the vehicle, and when the steering lock is engaged, the bolt is deployed into a recess formed in the shaft of the steering column, so as to prevent the latter being turned about its axis.
Such a device, in spite of the fact that it is so widely used, has a certain number of disadvantages. First, when the driver of the vehicle activates the locking system, locking does not take place automatically. In this connection, the steering lock is not properly effective, unless the bolt is engaged in the recess, which is only possible if the recess, and therefore the steering column, occupies a particular rotational position in which it is aligned with the bolt. While it has been proposed to provide the steering column with a set of several recesses, spaced apart angularly at regular intervals around the steering column shaft, on most occasions, the driver still has to maneuver the steering wheel before the steering lock can be properly engaged, so as to put a recess in the steering column into register with the bolt and thereby lock the antitheft device effectively.
This effective operation is generally detectable by a click which occurs as the bolt of the steering lock comes into its locked position. The steering column and the steering wheel then have no more than a very limited angular displacement.
In addition, such a conventional design of a steering column lock obliges the driver to act on the steering wheel at the instant of unlocking, so as to enable the bolt to be disengaged from the recess in the steering column shaft. In this connection, the friction forces of the bolt against the side walls of the recess can prevent withdrawal of the bolt, and it is necessary to effect an angular displacement of the bolt in the recess in order to be able to release the bolt, by eliminating the contact with the walls of the recess.
In addition, in current practice, during an attempt by a thief to break the steering lock, a very high torque is applied to the steering column through the steering wheel, in order to break the bolt or one of its actuating elements.
If the bolt and its actuating mechanism resist such efforts, the thief will try and apply even more force to the steering column, which can lead to damage to other parts of the steering system, such as the steering wheel or even the support of the steering column shaft.
On the other hand, if the bolt and its mechanism do yield, it can become possible to drive the vehicle. However, rupture of one of the components of the mechanism can give rise to serious problems as to operational reliability. The steering column may then become jammed while the vehicle is in motion.
DISCUSSION OF THE INVENTION
In order to solve these various problems, the invention proposes a new concept for a steering lock or antitheft device for a steering column.
According to the invention, an antitheft device for a motor vehicle steering column is characterised in that the steering column comprises a gear wheel which is fixed to the steering column in rotation about their common axis, in that the antitheft device comprises a pinion having an axis parallel to the axis of the steering column and of the gear wheel, the pinion being mounted for rotation on a moveable pinion support displaceable between a disengaged position, in which the pinion is disengaged and a position in which the pinion is engaged and in which the latter is in mesh with the gear wheel of the steering column, and in that immobilising means are provided for immobilising the pinion against rotation about its axis with respect to the pinion support, whereby to prevent rotation of the shaft of the steering column about its axis when the pinion is in its meshed position.
According to a preferred feature of the invention, the device including means for activating the device, the said activating means being adapted to displace the pinion from its disengaged position to its meshed position, and then to immobilize the pinion against rotation.
Preferably the trajectory of the pinion between its disengaged and meshed positions is substantially parallel to a common tangent of the pinion and the gear wheel of the steering column, such that the pinion reaches its meshed position by pivoting about its axis due to teeth of the pinion and gear wheel coming into contact with each other.
The support for the pinion is preferably arranged to slide in a rectilinear direction parallel to the tangent common to the gear wheel and pinion.
The pinion support is preferably arranged to pivot about an axis parallel to the axis of the steering column and parallel to the axis of the pinion.
According to another preferred feature of the invention, each tooth of the pinion and the gear wheel has a rounded tooth crest so as to cause scrapping of the teeth one against the other when two teeth of the pinion and gear wheel come into abutment against each other as the pinion is coming into mesh.
The means for immobilizing the pinion against rotation preferably includes means for limiting the torque by which the rotational movement of the pinion is blocked against such rotation.
According to a further preferred feature of the invention, the means for immobilizing the pinion include a friction device, at least one element of which is coupled in rotation to the pinion, the other element thereof being coupled in rotation with the support of the pinion.
Preferably then, the pinion is mounted for rotation on a spindle which is fixed to the pinion support, and the immobilizing means comprises a friction clutch including at least one fixed disc which is coupled in rotation to the spindle and to the pinion support, together with at least one moveable disc which is coupled in rotation to a cylindrical cage, the said cage being fixed with respect to the pinion for rotation with the latter, the discs being disposed within the cage, with at least some of the discs being moveable axially so that they can be pressed axially against each other.
This friction clutch preferably comprises a plurality of fixed discs coupled to the spindle, with each fixed disc being disposed axially between two moveable discs coupled to the pinion.
An element which is deformable elastically in the axial direction is preferably interposed between two consecutive moveable discs.
The means for immobilizing the pinion against rotation are preferably controlled by a cam device.
Further features and advantages of the invention will appear on a reading of the following detailed description of some preferred embodiments of the invention, which is given by way of non-limiting example only and with reference to the accompanying drawings.
REFERENCES:
patent: 1360616 (1920-11-01), Borck
patent: 1439414 (1922-12-01), Hanson
patent: 1512072 (1924-10-01), Williamson
patent: 3709055 (1973-01-01), Grove
patent: 5152363 (1992-10-01), Mertens et al.
patent: 5172576 (1992-12-01), Milton
patent: 5685180 (1997-11-01), Qualters et al.
patent: 0 623 495 (1994-04-01), None
patent: 587 057 (1925-04-01), None
patent: 337 444 (1930-10-01), None
patent: 339 940 (1930-12-01), None
Patent Abstracts of Japan, vol. 096, No. 012, Dec. 26, 1996 & JP 08 198057 (Koyo Seiko Co. Ltd.) Aug. 6, 1996.
Boulay Jean-Claude
Garnault Joel
Bucci David A.
Joyce William C
Morgan & Finnegan , LLP
Valeo Securite Habitacle
LandOfFree
Steering lock for a motor vehicle steering column does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Steering lock for a motor vehicle steering column, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Steering lock for a motor vehicle steering column will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2553983