FR2847218A1 - Anti-theft device for motor vehicle, has cam cooperating with main and spare counter-cams under normal and degraded operations, respectively, where cam profile has zone to enable respective counter-cam movements along zone length - Google Patents

Abstract

The device has a bolt for locking a steering column of a vehicle and a transformation unit to change rotational movement of a rotor (14) into a translatory movement of the bolt. A cam (28) cooperates with main (30) and spare counter-cams (32) under normal and degraded operations, respectively. The profile of the cam has a zone (40) to enable respective movements of the counter-cams along a length of the zone.

Description

-1 The present invention relates to an anti-theft device for a motor vehicle

for,

  in particular, to control the locking of a steering column of the vehicle.

  Already known in the prior art, in particular from FR-A-2 788 477 (FR-99 00401) or FR-A-2 799 426 (FR-99 11635), an anti-theft device for a motor vehicle, type comprising: - a stator, - a rotor mounted rotating in the stator between first and second extreme angular positions, - a bolt for locking a steering column of the vehicle, movable in translation between positions corresponding to released states and locked column, and - means for transforming the rotational movement of the rotor into translational movement of the bolt, coupling these rotor and bolt, comprising a cam intended to cooperate, in normal operation, with a

  main cam follower and, in degraded operation, with an emergency counter cam.

  In addition to the steering column lock control, the above type of anti-theft device is intended to control the starting of an engine of this vehicle. To this end, the rotor actuates an electrical switch with several positions. The rotor can be successively placed in a first extreme angular position of rest, called the "stop" position, an "accessory" position, a "on" position and a second position.

  extreme angular, opposite to the first, called "start" position.

  The bolt is generally movable between a position for releasing the steering column, called the retracted position, and a position for locking the steering column, called the extended position. The bolt extended position is usually only authorized when the rotor is in the "stop" position. However, when the rotor is in a position

  distinct from the "stop" position, the bolt is kept in the retracted position.

  Usually, the rotor is provided with a housing for a control key intended to operate this rotor. The insertion and removal of the key in the rotor housing is generally authorized only when the rotor is in its "stop" position. Conventionally, the anti-theft device comprises means automatically moving the bolt towards

  its extended position when, the rotor being in the "stop" position, the key is removed from the latter.

  The emergency counter cam automatically replaces the main counter cam in the event of accidental destruction of the latter, so as to ensure degraded operation of the anti-theft device. However, it is desirable that the transition from -2 normal operation to degraded operation be detected by the user in order to

  encourage him to have the lock repaired.

  The object of the invention is in particular to propose an anti-theft device of the aforementioned type in which the transition from normal operation to degraded operation is detected by the user. To this end, the subject of the invention is an anti-theft device for a motor vehicle, of the aforementioned type, characterized in that the profile of the cam comprises a first zone shaped so as to allow the respective paths of the main and

  emergency along this first area of the cam profile are distinct.

  The respective paths of the main and backup cams along the first area of the cam profile being distinct, certain aspects of the operation of the anti-theft device in degraded mode are different which allows the user to detect the

  transition from normal operation to degraded operation of the anti-theft device.

  Preferably, the rotor is provided with a housing for a control key intended to maneuver this rotor, the first extreme position of the rotor, called the "stop" position, authorizing the introduction and the withdrawal of the key in the housing of the rotor. , the respective paths of the main and backup cams between the first extreme position of the rotor and an intermediate angular position of the rotor, for example called position

  "accessories", being imposed by the first zone of the profile of the cam.

  Thus, the functions of the anti-theft device between the "stop" and

  "accessories" are different in normal and degraded modes.

  Also preferably, the first zone of the profile of the cam comprises a blocking stop intended to cooperate, in degraded operation, with the emergency counter-cam to prevent the rotor moved from its intermediate position towards its

  first extreme position to reach this first extreme position.

  Thus, the user detects the transition from normal operation to degraded operation of the anti-theft device by the impossibility of replacing the rotor in position.

  "stop" and therefore remove the key from the rotor.

  According to other optional characteristics of this anti-theft device - the cam has a general shape of revolution, the profile of the cam moving axially; - the main and backup cams have contact surfaces with the profile of the cam which, in normal operation, are offset axially and radially between them so that the main counter cam is in abutment on the profile of the cam while the emergency riser is kept away from the cam; -3 - the first zone of the cam profile comprises: * a radially internal zone of contact possible with the main cam follower and of contact impossible with the emergency counter cam, and * a radially external zone of contact impossible with the main cam follower and possible contact with the emergency counter cam, this radially external zone being delimited by an axial notch formed in the cam; - The axial notch is delimited by the blocking stop and a ramp allowing the displacement of the emergency counter cam between the blocking stop and the second zone of the profile of the cam; - The cam is linked in rotation of the rotor, the main and emergency cams being carried by a pull rod linked in translation to the bolt; - The main cam follower is formed by a finger attached to the pull tab; - The finger is articulated on the pull tab, around an axis substantially orthogonal to the axis of rotation of the rotor, and is returned elastically in contact with the profile of the cam; - the emergency cam follower is formed by a lug formed integrally with the pull tab; - The pull tab is resiliently returned to a position of axial support of the main or backup cam follower on the profile of the cam; - The rotor is intended to actuate an electrical switch with several positions.

  The invention will be better understood on reading the description which follows,

  given only by way of example and made with reference to the drawings in which: - Figure 1 is a cross-sectional view of an anti-theft device for a motor vehicle according to the invention; - Figure 2 is a sectional view of the lock shown in Figure 1 - Figure 3 is a perspective view of the bodies of the lock shown in Figure 2, the lock being in a normal operating configuration; - Figure 4 is a view similar to Figure 3 (rotor not shown), the lock

  being in a degraded operating configuration.

  The figures show an anti-theft device for a motor vehicle, according to the invention, designated by the general reference 10. The anti-theft device 10 is intended to control the locking of a vehicle steering column and the starting of a this vehicle. -4 Referring to Figure 1, we see that conventionally, the lock 10 comprises a stator 12 and a rotor 14 rotatably mounted in the stator 12 about an axis X parallel to a direction called axial. The rotor 14 is provided with a housing 16 for a key

  conventional control (not shown) intended to operate this rotor 14.

  To control various components of the vehicle including the engine, the rotor 14 is connected to a conventional electrical switch with several positions (not shown). Thus, the rotor 14, together with the electrical switch, can be placed in a first extreme angular position of rest, called "stop" position, a first intermediate angular position, called "accessories" position, a second intermediate angular position, called position "on", and a second extreme angular position, opposite to the first extreme position, called the "start" position. The "stop", "accessories", "start" and "start" positions follow one another when the rotor is moved from its

  first extreme angular position toward its second extreme angular position.

  The different positions of the rotor 14 are indexed using conventional means comprising, for example, a ball 20 slidingly mounted in a radial blind hole 22 formed in the rotor. The ball 20 is movable in the hole 22 between a retracted position in the rotor 14 and a projecting position of partial engagement in an indexing depression E1, E2 or E3 formed in the internal contour of the stator 12. In the example illustrated , the stator 12 is provided with three indentations E1, E2 and E3 intended to cooperate with the ball 20 to index respectively the "stop", "accessories" and "start" positions of the rotor 14. The "start" position of the rotor 14 is indexed

  by conventional complementary stops carried by the stator 12 and the rotor 14.

  The ball 20 is returned elastically to its projecting position, in contact with

  the internal surface of the stator 12, by a thrust spring 24 housed in the hole 22.

  The anti-theft device 10 also includes a bolt 26, shown diagrammatically in FIG. 2, allowing the steering column to be locked. The bolt 26 is movable in translation between positions corresponding to released and locked states of the column, called retracted and extended positions. The bolt 26 is returned elastically to its position

exit by conventional means.

  The anti-theft device 10 also comprises conventional means, not shown, which, when the rotor 14 is in the "stop" position, authorize the introduction of the control key into the housing 16 and the withdrawal of the key from this housing 16 and, when the rotor 14 is in a position distinct from the "stop" position, prohibit the removal of the key

housing 16.

  -5 The rotor 14 is coupled to the bolt 26 using means for transforming the

  rotational movement of this rotor 14 in translational movement of this bolt 26.

  With particular reference to FIG. 2, it can be seen that the movement transformation means comprise a cam 28 intended to cooperate, in normal operation, with a main counter cam 30 and, in operation

  degraded with an emergency cam follower 32.

  In the example shown in the figures, the cam 28 is linked in rotation to the

rotor 14.

  Preferably, the cam has a general shape of revolution around the axis X. The cam 28 is provided with a profile for cooperation with the main 30 and backup cams 32 moving axially according to characteristics particular to the invention which will be described below and general characteristics described in particular in

  FR-A-2 788 477 (FR-99 00401) and FR-A-2 799 426 (FR-99 11635).

  With particular reference to FIGS. 3 and 4, it can be seen that the profile of the cam 28 comprises a part L, called the release part, delimited by a surface which is substantially

  transverse of the cam, called the release face FL.

  The release part L of the profile is intended to cooperate with the cam follower

  main 30 to maintain the steering column in a released state.

  The profile of the cam 28 also includes a part V, called the locking part, delimited by a substantially transverse surface of the cam, called the locking face FV. This locking face FV is axially offset with respect to the face of

FL release.

  The locking part V of the profile is intended to cooperate with the main counter 30 to maintain the steering column in a locked state.

  The profile of the cam 28 further comprises a ramp R connecting the release L and locking parts V. The main counter cam 30 and the emergency counter cam 32 are carried by a pull rod 34 slidably mounted in the stator 12. The pull tab 34, preferably metallic, is linked, in a manner known per se, to the bolt 26, as shown diagrammatically in FIG. 2. The main 30 and backup 32 cams are secured in translation

zipper 34.

  In the example illustrated, the main cam follower 30 is formed by a finger 36, attached to the pull tab 34 while the emergency counter cam 32 is formed by a

  lug 38 formed integrally with the pull tab 34.

  -6 The finger 36 is articulated on the pull tab 34, in a manner known per se, about an axis substantially orthogonal to the axis X of rotation of the rotor 14. The finger 36 is recalled

  elastically in contact with the profile of the cam 28 by a thrust spring 39.

  The pull tab 34 is resiliently returned to an axial support position of each cam follower 30, 32 on the profile of the cam 28 using conventional means, not shown. It will be noted that the main 30 and backup 32 cams have contact surfaces with the profile of the cam 28 which, in normal operation, are offset axially and radially between them so that the main cam 30 is in abutment on the profile of the cam 28 while the emergency counter cam 32 is

  kept away from this cam 28.

  In the event of destruction of the main cam follower 30, the emergency counter cam 32 is automatically returned to bear against the profile of the cam 28. Thus,

  the emergency cam follower 32 automatically replaces the main cam follower 30.

  However, the different parts L, V, R of the profile of the cam 28 described above extend in one of the first and second zones of the profile described below.

  The first zone of the profile of the cam 28, to which the essential part of

  the ramp R, is shaped so as to allow the respective paths of the main cam 30 and emergency counter 32 along this first zone to be distinct.

  The second zone of the profile of the cam 28, to which the release part L belongs, is shaped so as to allow the respective paths of the main 30 and backup 32 cams along this second zone to be substantially identical. Referring to FIGS. 3 and 4, it can be seen that the first zone of the profile of the cam 28 has an axial notch 40 formed in the cam 28 so as to delimit along the ramp R: - a radially internal contact zone ZI possible with the main cam 30 and contact impossible with the emergency cam 32, and - a radially external zone ZE impossible to contact with the main cam 30 and possible contact with the cam

rescue 32.

  The axial notch 40 forms the radially external zone ZE.

  -7 Usually, when the rotor is in the "stop" position, the steering column being locked, the main cam follower 30 is supported on the locking part V

  of the profile of the cam 28, as shown in FIG. 3.

  When the rotor 14 is in one of the "accessory", "run" or "start" positions, the main cam follower 30 is in contact with the release part L of the

  profile of the cam 28, as shown in FIG. 2.

  Thus, the respective paths of the main 30 and backup cams 32 between the "stop" position and the "accessories" position of the rotor 14 are imposed, at least on part of these paths, by the first zone of the profile of the cam 28 including

  radially internal ZI and external ZE zones delimited by the ramp R and the notch 40.

  It will be noted that the axial notch 40 is delimited by: - a blocking stop 40A intended to cooperate, in degraded operation, with the emergency counter-cam 32 to prevent the rotor 14 moved from its "accessories" position to its position " stop "to reach this" stop "position, - and a ramp 40B authorizing the displacement of the emergency cam follower 32 between the blocking stop 40A and the release part L of the profile of the

  cam 28 belonging to the second zone of this profile.

  It will therefore be noted that the substantially identical paths of the main 30 and backup 32 cams between the "accessory" and "start" positions are

  imposed by the second zone of the profile of the cam 28.

  The main aspects of the operation of the lock will be specified below

related to the invention.

  The rotor 14 is initially considered in the "stop" position, the steering column being locked. In this "stop" position, a control key can be entered

  in the housing 16 of the rotor 14 by a user wishing to operate the anti-theft device.

  In normal operation, the main cam follower 30 is supported on the

  locking part V of the profile of the cam 28, as shown in FIG. 3.

  The displacement of the rotor 14 successively in the "accessory", "on" and "start" positions has the effect of moving the main cam 30 in contact

  of the profile of the cam 28, in accordance with conventional paths.

  During normal anti-theft operation, the emergency cam follower 32

  is not in contact with the profile of cam 28.

  If the rotor 14 being in one of the "accessory", "running" or "starting" positions, the main counter cam 30 is destroyed, the emergency counter cam 32 is then automatically urged to bear against the part of release L from the profile of the

  cam 28 belonging to the second zone of this profile.

  The displacement of the rotor 14 towards the "stop" position then has the effect of fitting the emergency cam follower 32 into the notch 40, the locking stop 40A preventing the rotor 14 from reaching this "stop" position, as this is depicted on the

figure 4.

  Thus, the user can no longer remove the key from the housing 16 and therefore finds

  the lock is damaged so it needs to be repaired.

  On the other hand, the user has the possibility of replacing the rotor 14 in one of the "accessory", "on" or "start" positions by cooperation of the cam follower of

  emergency 32 with the ramp 40B delimiting the notch 40.

  In particular, when the rotor 14 moves from the "stop" position to the "accessories" position, the main cam follower 30 cooperates with the internal zone ZI of the first zone of the profile of the cam 28, this internal zone ZI s extending along the ramp R. It will therefore be noted that the notch 40, reducing the width of the ramp R, makes it possible to prevent the rotor 14 from returning to the "stop" position when the main cam follower 30

is destroyed.

-9

Claims (15)

  1. Anti-theft device for a motor vehicle, of the type comprising: - a stator (12), - a rotor (14) mounted rotating in the stator (12) between first and second extreme angular positions, - a bolt (26) for locking the 'a vehicle steering column, movable in translation between positions corresponding to released and locked states of the column, and - means for transforming the rotational movement of the rotor (14) into translational movement of the bolt (26), coupling these rotor (14) and bolt (26), comprising a cam (28) intended to cooperate, in normal operation, with a main cam follower (30) and, in degraded operation, with a backup cam follower (32 ), characterized in that the profile of the cam (28) comprises a first zone (R, 40) shaped so as to allow the respective paths of the main (30) and emergency (32) counter cams along this first zone (R, 40) of the profile of the cam (28) are separate.   2. Anti-theft device according to claim 1, characterized in that the profile of the cam (28) comprises a second zone (L) shaped so as to allow the respective paths of the main (30) and backup (32) cams along this second   zone (L) of the profile of the cam (28) are substantially identical.   3. Anti-theft device according to claim 1 or 2, characterized in that the rotor (14) is provided with a housing (16) for a control key intended to operate this rotor (14), the first extreme position of the rotor (14 ), called the "stop" position, authorizing the introduction of the key into the housing (16) of the rotor (14) and the withdrawal of the key from this housing (16), at least part of the respective paths of the cams main (30) and emergency (32) between the first extreme position of the rotor (14) and an intermediate angular position of the rotor (14), for example called the "accessories" position, being imposed by the   first zone (R, 40) of the profile of the cam (28).   4. Anti-theft device according to claims 2 and 3 taken together, characterized in that   that the substantially identical paths of the main (30) and emergency (32) cams between the intermediate angular position and the second extreme position of the rotor (14), called the "start" position, are imposed by the second zone (L) of the profile of the cam (28).   -10 5. Anti-theft device according to claim 3 or 4, characterized in that the first zone (R, 40) of the profile of the cam (28) comprises a blocking stop intended to cooperate, in degraded operation, with the emergency counter-cam (32 ) to prevent the rotor (14) moved from its intermediate position to its first extreme position from reaching this first extreme position.   6. Anti-theft device according to any one of the preceding claims, characterized   in that the cam (28) has a general shape of revolution, the profile of the cam (28) evolving axially.   7. Anti-theft device according to claim 6, characterized in that the main (30) and emergency (32) counter cams have contact surfaces with the profile of the cam (28) which, in normal operation, are offset axially and radially between them so that the main cam (28) (30) is in abutment on the profile of the cam (28) while the emergency counter cam (32) is kept away from the cam (28).   8. Anti-theft device according to claim 6 or 7, characterized in that the first zone (R, 40) of the profile of the cam (28) comprises: - a radially internal zone (ZI) of possible contact with the main cam follower ( 30) and impossible contact with the emergency cam follower (32), and - a radially external zone (ZE) of impossible contact with the main counter cam (30) and possible contact with the emergency cam follower (32) , this radially outer zone (ZE) being delimited by a   axial notch in the cam (28).   9. Anti-theft device according to claims 2, 5 and 8, characterized in that the notch   axial is delimited by the locking stop (40A) and a ramp (40B) authorizing the displacement of the emergency counter cam (32) between the locking stop and the second area (L) of the profile of the cam (28).   10. Anti-theft device according to any one of the preceding claims,   characterized in that the cam (28) is linked in rotation to the rotor (14), the main (30) and emergency (32) cams being carried by a pull tab (34) linked in translation to the bolt (26).   11. Anti-theft device according to claim 10, characterized in that the counter-frame   main (30) is formed by a finger (38) attached to the pull tab (34).   12. Anti-theft device according to claim 11, characterized in that the finger (38) is articulated on the pull tab (34), around an axis substantially orthogonal to the axis (X) of rotation   of the rotor (14), and is returned elastically in contact with the profile of the cam (28). -11   13. Anti-theft device according to any one of claims 10 to 12, characterized in   that the emergency cam follower (32) is formed by a lug (38) made integrally with the pull tab (34).   14. Anti-theft device according to any one of claims 10 to 13, characterized in   that the pull tab (34) is resiliently returned to an axial support position of the   main (30) or emergency (32) cam follower on the cam profile (28).   15. Anti-theft device according to any one of the preceding claims,   characterized in that the rotor (14) is intended to actuate an electrical switch with several positions.