FR2714344A1 - Motor vehicle steering wheel anti-theft device - Google Patents

Abstract

The device consists of a spring-loaded thrust disc (5) which is pressed towards a second disc (7) on the end of a sleeve (2) surrounding the steering shaft (1). The two discs are engaged through balls which sit in hemispherical recesses in one disc and engage with radial ribs on the other, the number of recesses and ribs being equal, so that each ball lies between two ribs. In the normal position the sleeve and discs rotated together with the steering shaft, while in the locked position the sleeve is held still by the locking mechanism bolt. When the steering wheel is turned one disc can rotate relative to the other only by the balls overcoming the pressure of the spring to pass over the ribs and preventing normal steering.

Description

 The present invention relates to a device intended to make it impossible to drive a motor vehicle and more particularly to devices preventing normal action on the wheels by means of the steering wheel when the anti-theft device is in the active position.

 Devices of this general type exist according to many different embodiments which can be used to prevent normal action on the wheels, a characteristic common to most of the known devices is the blocking of the steering rod. This arrangement has certain advantages, but also a disadvantage in that a violent torque applied to the steering wheel can cause the ineffectiveness of the anti-theft device again allowing normal action on the wheels.

The anti-theft device according to the invention overcomes this drawback, it in fact comprises, according to a first characteristic, a steering rod provided with a multiple cam core in which the finger of an anti-theft device, of the type with steering lock, machined so as to be able to cross the curves of successive cams only under the effect of a large torque applied to the steering wheel;
Torque which will be upset by the action of a calibrated spring, which will make driving impossible.

 According to particular embodiments, the calibrated spring placed inside the lock, of the steering direction type, can be replaced by several springs arranged on the flanges of a two-piece lock support. .

 The accompanying drawings it] ustrent the invention: The f -re 1 represeri to? Orspective of the tive direction with sor oyal reams multiplets.

The fife 2 represents a cross section of the complete steering column at the level of the X-Y cutting axis of the cab 1.

Figure 3 shows a variant of this device.

 With reference to these drawings, the device comprises a steering rod (1) provided with a multiple cam core (2) which will receive in the lower curve, produced between two adjacent cams the finger (3) of a type anti-theft device. with direction lock C, machined into the shape of a cylindrical rod, its end having a rounded shape, the curve of which corresponds exactly to the profile of the lower curves made between two adjacent cams of the core (2) at the bottom of which it will lock to prevent normal rotation of the steering rod when normal torque is applied to the steering wheel. Under the effect of a higher torque, thwarted by the effect of a calibrated spring, not shown, which replaces the original spring of the steering lock type lock, the end of the finger ( 3) will retract by sliding on the ascending curve of one or the other of the adjacent cams between which it will have taken position and will be found on the upper curve of the cam which will have pushed it, to fall back into the lower curve of the following cams, requiring a significant new effort for a new tiny movement of the wheels, thus making driving the vehicle impossible.

In the embodiment according to FIG. 3, the support of the anti-theft device
C is produced in two parts A and 9, each provided with a flange (4) or are made, on the flange of A, three smooth holes allowing the passage of the rods of the bolts (5) screwed into three tapped holes made on the flange of P. The calibrated springs (6) were placed on the want before screwing, their pressure adjustment is obtained by tightening then final locking of the three bolts.
the device according to the invention is particularly intended to serve as an anti-theft device on motor vehicles.

Claims (5)

I) antitheft anti-theft steering device for motor vehicles, characterized in that it comprises a steering rod (1) provided with a multiple cam core (2) in the lower curve of which the finger (3) will be placed d an anti-theft device of type C direction locking, urged by at least one calibrated spring, and machined in the form of a cylindrical rod whose end has a rounded exactly corresponding to the profile of the lower curves between two adjacent cams of the core (2), at the bottom of which it will lock, but may retract under the effect of a significant torque applied to the steering wheel, following the ascending curve of one or the other of the adjacent cams, then arriving at the top of that -this, to fall back into the next lower curve, never ceasing a new significant effort for a tiny movement of the wheels, making driving impossible. 2) Device according to claim I characterized in that the core (2) constitutes a part of the steering rod (1) and comprises successive cams whose profile prevents rotation of the steering wheel without significant and jerky effort. 3) Device according to claim 1 or 2 characterized in that a calibrated spring is placed inside the lock type C steering lock 4) Device according to claim 1 or 2 characterized in that the support of the steering lock type lock is made in two parts connected by three bolts (5) on the flanges (4) by means of the calibrated springs ( 6). 5) Device according to claim 1 or 2 characterized in that the force of the finger is produced by three calibrated springs (6) mounted on the rods of the support fixing bolts.