Abstract:
A lock for an antitheft device for a motor vehicle steering column is provided and includes a stator having a stator head with an opening, a rotor rotatably mounted about an axis with respect to the stator having an annular flange, a cam to rotate as one with the rotor, and an elastic element arranged between the cam and the rotor in order to exert a thrust load axially on the rotor. The opening of the stator is designed to engage with the annular flange to prevent the rotor from rotating in a predetermined rotation direction from a predetermined angular position and allows the rotor to rotate beyond the predetermined angular position by prior depression of the rotor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/EP2015/072616, filed on Sep. 30, 2015, which claims priority to and the benefit of FR 14/59370 filed on Oct. 1, 2014. The disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a lock for a steering column anti-theft of a motor vehicle. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0004]    It is known that anti-theft devices for steering columns, comprising at least, a stator, a rotor and a cam, may be held in distinct positions thanks to different indexed angular positions: 
         [0005]    a neutral extreme angular “Stop” position, in which the anti-theft locks the steering column; 
         [0006]    an intermediate angular “On” position, in which the vehicle is electrically powered, and enables the start-up of the thermal engine of the vehicle; and 
         [0007]    an active extreme angular “Start” position, in which besides the “On” functions, the starter is powered to start up the thermal engine of the vehicle. 
         [0008]    Of course, other positions may exist such as for example the intermediate angular “Accessories” position, allowing to electrically power some accessories, such as the radio, typically disposed between the neutral extreme angular “Stop” position and the intermediate angular “On” position. 
         [0009]    Once the engine is operated, the anti-theft is automatically brought back from the “Start” position to the “On” position by a return force. The “On” position is the position used during the running of the vehicle. 
         [0010]    There is known a mechanical indexing system which allows holding the key, rotor, and cam assembly in a stable position unless an intentional action of the user modifies this position in order, for example, to shut off the engine by turning the key from the “On” position to the “Stop” position. An “intentional action of the user” is called a simple rotation of the key against the indexing torque, for example in the range of 0.2 to 0.4 N·m. 
         [0011]    A first drawback of this type of lock is that the key may come out from its indexed position in the event of unintentional action of the type “knee kick on the key when driving”. In this case, the anti-theft may then reach an angular position where the electric “On” functions are no longer ensured, and therefore cause the unintentional stopping of the engine when running. 
         [0012]    A second drawback of this type of lock is that, during an engine start, because of the automatic return of the key into the “on” position by spring return, if the key is brutally released without hand assistance from the “Start” position to the “On” position, the indexed “On” position may be exceeded due to the inertia of the key, rotor, and cam assembly. The anti-theft is then positioned in a non-indexed (and non-stable) angle. Consequently, the running vibrations may bring the anti-theft in an angular position where the electric “On” contact is lost, resulting in an unintentional stopping of the engine. 
       SUMMARY 
       [0013]    The present disclosure provides a lock for a steering column anti-theft of a motor vehicle comprising: 
         [0014]    a stator comprising a stator head in which an opening is arranged, 
         [0015]    a rotor movably mounted in rotation relative to the stator about an axis and comprising an annular collar, 
         [0016]    a cam intended to be rotatably secured to the rotor, and 
         [0017]    an elastic element arranged between the cam and the rotor for axially biasing said rotor by pushing, 
         [0018]    wherein the opening is shaped so that its cooperation with the annular collar blocks the rotation of the rotor in a predetermined direction of rotation from a predetermined angular position and enables the rotation of the rotor beyond the predetermined angular position by pressing the rotor beforehand. 
         [0019]    Such a lock for a steering column anti-theft of a motor vehicle presents a new kinematic of the rotor to switch from the intermediate angular “On” position to the neutral extreme angular position called “Stop” position related to the stopping of the engine. Thus, when the anti-theft is in the “On” position, the user pushes the key in order to perform the rotation in the direction of the “Stop” position. 
         [0020]    If the key is not pushed, its rotation is inhibited. Thus, it may not be possible, in the event of unintentional action of the type “knee kick on the key when driving”, to get the key out of its indexed position by causing the unintentional stopping of the engine when running. 
         [0021]    Similarly, it may not be possible to cause the unintentional stopping of the engine during the automatic return of the key into the “On” position by a return force, when the key is brutally released without hand assistance from the active extreme angular “Start” position to the “On” position. 
         [0022]    Thus, the lock of the present disclosure allows, in a simple and very effective manner, to reduce the security issues of the prior art. 
         [0023]    According to one form, the lock for a steering column anti-theft of a motor vehicle according to the present disclosure comprises one or more of the following features, considered separately or in combination: 
         [0024]    the annular collar comprises an extension which extends axially toward the head of the rotor intended to receive an insert over a first angular sector; and 
         [0025]    the opening is substantially circular and includes a clearance for enabling the passage of the extension of the annular collar, the clearance extending radially outward of the opening over a second angular sector and being shaped so that its cooperation with the annular collar retains axially the rotor in the head of the stator; 
         [0026]    the predetermined angular position is an intermediate angular position disposed between a neutral extreme angular position and an active extreme angular position; and 
         [0027]    the opening is shaped so that its cooperation with the annular collar enables the rotation of the rotor in a direction of rotation opposite to the predetermined direction of rotation up to an active extreme angular position, such as the start position. 
         [0028]    According to another form, the present disclosure also teaches a steering column anti-theft for a motor vehicle, characterized in that it includes at least one lock as defined hereinbefore. 
         [0029]    In the context of the present disclosure, for an element extending in the space in three perpendicular directions, said element is defined as a radial extension, namely an extension extending radially, if its size in a direction parallel to a radius of the rotor is larger than its size in the two other perpendicular directions; and said element is defined as an axial extension, namely an extension extending axially, if its size in a direction parallel to the axis of rotation of the rotor is larger than its size in the two other perpendicular directions. 
         [0030]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0031]    In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
           [0032]      FIG. 1  is a perspective view of a steering column anti-theft for a motor vehicle according to the present disclosure; 
           [0033]      FIG. 2  is an exploded view of the lock of the anti-theft of  FIG. 1 ; 
           [0034]      FIG. 3  is a perspective view of the rotor of the lock of  FIG. 2 ; 
           [0035]      FIG. 4  is a perspective view of the stator head of  FIG. 2 ; 
           [0036]      FIGS. 5 and 6  are cross-sectional views of the lock of  FIG. 2  respectively when the rotor is in a position called “stowed” position ( FIG. 5 ) and a position called “deployed” position ( FIG. 6 ); 
           [0037]      FIG. 7  illustrates a perspective view of the lock of  FIG. 2  with the rotor of the lock in the “deployed” position; 
           [0038]      FIGS. 8 and 9  are cross-sectional views of the lock of  FIG. 2  respectively when the lock is in the “Stop” ( FIG. 8 ) and “On” ( FIG. 9 ) positions; and 
           [0039]      FIG. 10  is a view similar to  FIG. 9 , illustrating the driver pressing the rotor to switch from the “On” position to the “Stop” position in order to be able to remove the key. 
       
    
    
       [0040]    In the different figures, the similar elements are indicated by identical reference numerals. Furthermore, the different elements are not necessarily to scale in order to present a view allowing facilitating the understanding of the present disclosure. 
         [0041]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
       DETAILED DESCRIPTION 
       [0042]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
         [0043]      FIG. 1  illustrates a steering column anti-theft  2 , with an insertable lock, intended to be mounted in a motor vehicle so as to secure its direction. The anti-theft  2  comprises an anti-theft body  4  inside which a lock  6  is intended to be inserted and secured. 
         [0044]    As represented in the exploded view of  FIG. 2 , the lock  6  includes a stator  8 , a rotor  10 , a cam  12  and an elastic element  14 . 
         [0045]    The stator  8  comprises a stator  16  head. The head of the stator  16  may be secured to the anti-theft body  4 . At the front, an opening  18  is arranged in the rotor head in order to provide access to the head of the rotor. At the rear, the stator  16  head has a housing with a shape adapted to receive the rotor  10 , for example a general cylindrical shape. 
         [0046]    The rotor  10  is movably mounted in rotation relative to the stator about an axis noted I-I. The rotor can be movable in axial rotation about this axis I-I by rotational driving of a key insert so as to control a locking means of the anti-theft  2 . 
         [0047]    The rotor  10  has a key inlet  20  arranged at the front end also called rotor head. It is understood that, throughout this text, the term rotor refers, in a very general manner, to any sub-assembly comprising a rotor body through which are arranged radial slots  22  capable of receiving flakes which are movably mounted in radial translation and which are coupled to return springs bringing them permanently in protruding positions with respect to the body of the rotor. The flakes allow the release of the rotor when a key insert corresponding to the coding formed by the arrangement of the flakes is introduced in the rotor. 
         [0048]    The rotation of the key may cause the rotation of the rotor  5  in a first neutral extreme angular position, called neutral position, such as the “Stop” position, two intermediate angular positions, called “On” and “Accessories” positions and a second active extreme angular position, opposite to the first neutral extreme angular position, called “Start” position. 
         [0049]    The “Neutral”, “Intermediate” and “Start” positions follow one another when the rotor  10  is displaced from the “Neutral” position toward the “Start” position. After passing through the start position, the rotor  10  is resiliently brought back to its intermediate “On” position by a return spring. 
         [0050]    The locking means includes a bolt  24  movably mounted between a retracted position in which the bolt  24  is kept away from a steering column (not represented) and a protruding position, as illustrated in  FIG. 1 , in which it blocks the steering column of the motor vehicle. 
         [0051]    For this purpose, the cam  12  is intended to be rotatably secured to the rotor, so that the rotation of the rotor  10  allows controlling the translation of the bolt  24 . 
         [0052]    The bolt  24  is generally in a protruding position in the steering column when the rotor  10  is in the neutral position, the bolt  24  being kept stowed, in the retracted position, in the other angular positions of the rotor  10 . The bolt  24  is biased by pushing in the protruding position by a bolt spring. 
         [0053]    The elastic element  14  is arranged coaxially between the cam  12  and the rotor  10  so as to axially bias said rotor  10  by pushing. For example, the elastic element  14  is a compression spring. Thus, the spring  10  is slidably linked to the cam  12 , that is to say that the rotor  10  is linked in rotation with the cam  12  but not in translation, the elastic element  14  pushing the rotor  10  in a non-pressed position. 
         [0054]    Furthermore, the rotor  10  comprises an annular collar  26 . 
         [0055]    According to the present disclosure, the opening  18  is shaped so that its cooperation with the annular collar  26  blocks the rotation of the rotor  10  in a predetermined direction of rotation from a predetermined angular position and enables the rotation of the rotor  10  beyond the predetermined angular position by prior pressing of the rotor. 
         [0056]    According to one form of the present disclosure, the predetermined angular position is an intermediate angular position, for example the “On” position, disposed between a neutral extreme angular position, the “Stop” position and an active extreme angular position, the “Start” position. 
         [0057]    By this means, the key cannot be extracted from the lock  6  by a simple removal movement in the “Stop” position. It may be necessary to press the key beforehand in the lock  6  in order to be able to extract it therefrom afterwards. Thus, any unintended or malevolent extraction of the key may be inhibited, in particular because of the danger that the extraction of the key poses when the vehicle is running. 
         [0058]    According to one form of the present disclosure, shown in  FIGS. 3 and 4 , the annular collar  26  comprises an extension  28  which extends axially toward the head of the rotor  10  over a first angular sector with an angle θ 1 . 
         [0059]    Furthermore, the opening  18  is substantially circular with a radius R 1  and includes a clearance  30  for enabling the passage of the extension  28  of the annular collar  26 . The clearance  30  extends radially outward of the opening  18  over a second angular sector with an angle noted θ 2 . In other words, over the second angular sector with the angle noted θ 2 , the assembly formed by the opening  18  and the clearance  30  is substantially circular with a radius R 2  larger than the radius R 1 . The angle θ 2  is at least equal to the angle θ 1 . 
         [0060]    The clearance  30  also includes a radial stop  32  shaped to block the rotation of the rotor  10 , during the rotation of the rotor  10  in the counterclockwise direction from the predetermined angular position. 
         [0061]    In addition, the clearance  30  is shaped so that its cooperation with the annular collar  26  retains axially the rotor  10  in the head of the stator  16 . To this end, the stator  16  head has an axial stop  34  located at the front side of the rotor. The axial stop  34  is shaped to retain axially the rotor  10  in the stator  16  head while enabling the pressing of the rotor  10 . 
         [0062]    In other words: 
         [0063]    when the extension  28  of the annular collar  26  does not face the clearance  30 , the rotor is retained in translation in a position called “stowed” position as illustrated in  FIG. 5 ; and 
         [0064]    when the extension  28  of the annular collar  26  faces the clearance  30 , the rotor is pushed by the elastic element  14  and consequently translates along the axis I-I into a position called “deployed” position as illustrated in  FIGS. 6 and 7 . 
         [0065]    According to another form, the opening is further shaped so that its cooperation with the annular collar  26  enables the rotation of the rotor in a direction of rotation opposite to the predetermined direction of rotation up to an active extreme position, such as the “Start” position. Thus, according to the present disclosure, the angle θ 2  is larger than the angle θ 1  thereby enabling a rotation of the rotor  10  in the clockwise direction between the “On” position and the “Start” position, that is to say when the rotor  10  is in the “deployed” position. 
         [0066]    The clearance  30  further includes an additional radial stop  36  corresponding to the “Start” position shaped to block the rotation of the rotor  10  in the direction of rotation opposite to the predetermined direction of rotation, that is to say in the clockwise direction beyond the “Start” position. 
         [0067]    An example of operation of the lock will now be described with reference to  FIGS. 8 to 10 . 
         [0068]    It is assumed, with reference to  FIG. 8 , that the vehicle is stopped and that the driver introduces the key (not represented) in the rotor  10  along the axis I-I so as to start up the vehicle. The lock  6  is then in the angular “Stop” position indicated PS in  FIG. 4 . The rotor is in the “stowed” position. 
         [0069]    Then, the user begins turning the key in the clockwise direction of rotation, making the rotor  10  turn in the stator  16  head. As long as the lock  6  has not reached the predetermined angular position, for example the intermediate “Start” position PIM, the rotor  10  remains in the “stowed” position. 
         [0070]    When the rotor  10  reaches the predetermined intermediate position for example the “On” position PIM ( FIG. 9 ), the rotor  10  translates into the “deployed” position under the action of the spring  14  according to the arrow F 1  ( FIG. 9 ). The axial stop  34  axially retains the rotor  10  in the stator  16  head in this “deployed” position. 
         [0071]    As soon as the rotor  10  reaches this “deployed” position, the extraction of the key is inhibited. 
         [0072]    The rotation of the rotor  10  may be continued in the clockwise direction up to the “Start” position. Between the predetermined angular position, herein the intermediate “On” position and the angular “Start” position, the rotor  10  remains in the “deployed” position under the action of the spring  14  and is retained in the stator  16  head by the axial stop  34 . 
         [0073]    The rotation of the rotor  10  in the clockwise direction is inhibited beyond the “Start” position by the abutment of the extension  28  of the collar  26  against the radial stop  36 . 
         [0074]    After the engine starts in the “Start” position, the lock automatically returns in the “On” position, the rotor remaining in the “Deployed” position during its rotation in the counterclockwise direction. 
         [0075]    From the predetermined angular position, the “On” position in this example, when the driver turns the key in the reverse direction (counterclockwise direction of rotation), the rotation of the rotor  10  is prohibited by the abutment of the extension  28  of the collar  26  against the radial stop  32 . Hence, it may not be possible to make the rotor  10  turn from the intermediate “On” position PIM in order to make it return to the “Stop” position and remove the key. 
         [0076]    In this stop position, the driver then presses the rotor  10  into the stator  16  head (arrow F 2  in  FIG. 10 ), thereby enabling overcoming the radial stop  32  by the extension  28  of the collar  26 . 
         [0077]    Before reaching the “Stop” position PS, the rotor  10  returns into the initial “stowed” position ( FIG. 8 ) until the abutment of the extension  28  of the collar  26  against the axial stop  34 . 
         [0078]    Then, the driver continues turning the rotor  10  until reaching the stop position in which the driver can then extract the key from the lock  6 . 
         [0079]    The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.