Abstract:
The mechanism for adjusting the tilt of an automobile vehicle seat comprising a first flange entirely obtained from a shaped metallic element, a second flange comprising a central part and a peripheral part is disclosed. The internal face of the first flange is opposite the external face of the second flange to guide a rotational movement of the flanges. The retaining face of the first flange is opposite the rear face of the second flange, to retain the second flange in the first flange along the pivot axis.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to the mechanisms for adjusting the tilt of an automobile vehicle seat, the vehicle seats equipped with such mechanisms, and the manufacturing methods of such mechanisms. 
       BACKGROUND 
       [0002]    More particularly, the invention concerns a mechanism for adjusting the tilt of an automobile vehicle seat comprising:
       a first flange entirely obtained from a shaped metallic element, comprising a front face, an internal face that is at least partially cylindrical around a pivot axis, and a retaining face,   a second flange comprising a central part and a peripheral part featuring a front face that is opposite the front face of the first flange, an external face at least partially cylindrical around the pivot axis, and a rear face.       
 
         [0005]    The document FR 2 578 601 describes an example of such a tilting adjustment mechanism. In this document, a ring is used, attached to one of the flanges, and crimped onto the other, to hold the two flanges together to prevent a relative movement thereof along the pivot direction. 
         [0006]    However, it is still sought to improve such systems, and in particular to simplify them whilst maintaining their operational functions intact. 
       SUMMARY 
       [0007]    Consequently, a mechanism of the type in question is characterised in that the internal face of the first flange is opposite the external face of the second flange to guide a relative rotational movement of the first and second flanges around the pivot axis,
       and in that the retaining face is opposite the rear face of the second flange, to retain the second flange in the first flange along the pivot axis.       
 
         [0009]    Thanks to these measures, the additional ring is no longer required, which reduces the supply and logistics problems for the parts, and reduces the number of assembly operations. 
         [0010]    In certain embodiments, the following measures may also possibly be used:
       the mechanism further comprises a grain borne by the first flange, wherein said grain comprises a first locking surface,   the second flange comprises an internal face that is at least partially cylindrical around the pivot axis, and which is opposite the external face of the second flange, wherein said internal face of the second flange comprises a second locking surface,   said grain is fitted so that it is mobile on the first flange between
           an active position in which the first and second locking surfaces engage so as to prevent any relative rotation of the first and second flanges around the pivot axis, and   an inactive position in which the first and second locking surfaces do not engage, to allow said rotation;   
           the first flange is fitted with a plurality of retaining portions, distributed around the pivot axis, and each comprising a said retaining face;   retaining face and internal face of the first flange are angularly offset with respect to one another around the pivot axis;   the mechanism further comprises a radial opening between the retaining face and the internal face of the first flange;   the first flange comprises:
           a central plate featuring the front face, and   a peripheral crown around the pivot axis, extending from the central plate, wherein said peripheral crown comprises an internal face forming said internal face of the first flange, and at least one retaining element, which protrudes with respect to said internal face, wherein said protrusion bears said retaining face.   
               
 
         [0022]    According to another aspect, the invention concerns an automobile vehicle seat comprising a first element, a second element, and such a mechanism, wherein the first flange is fixed to the first element and the second flange is fixed to the second element. 
         [0023]    According to another aspect, the invention concerns a manufacturing method for a mechanism for adjusting the tilt of an automobile vehicle seat in which:
       (a) a first flange is entirely obtained from a shaped metallic element to comprise a front face, an internal face that is at least partially cylindrical around a pivot axis, and a retaining face,   (b) a second flange is provided comprising a central part and a peripheral part featuring a front face designed to be opposite the front face of the first flange, an external face that is at least partially cylindrical around the pivot axis, and a rear face,   (c) the first and second flanges are placed such that the front face of the first flange is opposite the front face of the second flange and the internal face of the first flange is opposite the external face of the second flange to guide a relative rotational movement of the first and second flanges around the pivot axis,   (d) the first flange is deformed such that the retaining face is opposite the rear face of the second flange, to retain the second flange in the first flange along the pivot axis.       
 
         [0028]    In certain embodiments, it may be necessary to use one and/or the other of the following measures:
       in step (d), a retaining portion of the first flange is deformed radially toward the pivot axis, and longitudinally toward the front face of the first flange, to press a retaining face of the retaining portion onto the rear face of the second flange;   in step (a), a first flange is obtained comprising a radial opening between the front face and a retaining portion featuring the retaining face.       
 
         [0031]    Other features and advantages of the invention will become clearer in the following description of one of its embodiments, provided by way of non-restrictive example, in reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    In the drawings: 
           [0033]      FIG. 1  is a diagrammatical side view of an automobile vehicle seat, 
           [0034]      FIG. 2  is an exploded perspective view of an adjustment mechanism, 
           [0035]      FIG. 3  is a partial view of two flanges of an adjustment mechanism, according to two different perspectives, 
           [0036]      FIG. 4  is a view which corresponds to  FIG. 3  for one of the two flanges at an intermediate step of the manufacturing method, 
           [0037]      FIGS. 5   a  and  5   b  are two identical plane views at two successive steps of an assembly method, and 
           [0038]      FIGS. 6   a  and  6   b  are two cross sectional views according to the VI-VI line respectively in  FIG. 5   a  and  FIG. 5   b.    
       
    
    
       [0039]    In the different figures, the same references are used to designate identical or similar elements. 
       DETAILED DESCRIPTION 
       [0040]    As shown diagrammatically in  FIG. 1 , the invention concerns a seat  1  of a vehicle which features a seat chair  2  mounted on a vehicle floor  3  and a seat back  4  mounted so that it pivots on the seat chair  2  by at least one articulated mechanism  5 , around a main articulation axis Y which extends transversally and substantially horizontally. 
         [0041]    The articulation mechanism  5  has for example a single level and may be commanded for example by means of a handle  6  which may be actuated in the direction  6   a  to release the pivoting of the seat back  4  around the main axis of rotation Y. 
         [0042]    As illustrated in  FIGS. 2 to 6   b , the articulation mechanism  5  essentially comprises a first flange  10 , a second flange  20 , three locking elements  11 ,  12 ,  13 , or “grains”, a movement transfer element  30 , or “cam”, and a command rod (not shown), which passes through the central opening of the cam and each of the flanges. 
         [0043]    The general form of the first flange  10  is a rigid disc, formed by stamping, which is fixed for example to the chair  2  of the seat. It features a bore extending along the main axis of rotation Y and forms a passage  18  for the command rod, and is connected to the handle  6 . 
         [0044]    It further comprises three circular shaped guiding elements  14 ,  15 ,  16  which are identical and are distributed on the periphery around the main axis of rotation, for example at 120°. 
         [0045]    The first flange  10  further features three additional retaining elements  34 ,  35 ,  36  which are each respectively positioned circumferentially between two grains  11 ,  12 ,  13 . These three elements are for example identical, only the element  34  will be described below: it features a first surface opposite a complementary surface of the grain  11  and a second surface opposite a complementary surface of the grain  12  (all cylindrical with a generating line parallel to the Y axis). 
         [0046]    The first flange  10  thus has a central plate  50  that is substantially flat normal to the Y axis, featuring a front face  39  and a rear face  51  opposite. The guiding elements  14 ,  15 ,  16  and the retaining elements  34 ,  35 ,  36  are formed by stamping, so that they protrude with respect to the plane of the front face  39 . Similarly, holding patterns may be formed, either protruding or depressed, in the rear face  51 , for example to help attach the flange on an element frame of an automobile vehicle seat. 
         [0047]    The first flange  10  also features a peripheral crown  9  featuring a cylindrical internal face  52  revolving around the Y axis, orientated towards this axis, and an opposite cylindrical external face  53  revolving around the Y axis, orientated opposite to this axis, and positioned further away from the axis than the internal face  52 . 
         [0048]    The peripheral crown  9  also features a front face  54  parallel to the front face  39  of the central plate  50 , and which joins the inside  52  and external  53  faces. 
         [0049]    As may be seen in  FIG. 3 , the peripheral crown  9  is equipped, in a distal region (i.e. distant from the central plate) with longitudinal retaining elements  42 , which protrude radially inwards with respect to the cylindrical revolution internal surface  52 . These retaining elements  42  may be for example distributed circumferentially around the Y axis, for example uniformly. There is a plurality of distinct elements. In the example provided, there are five of them. They each have a front face  56  that continues from the front face  54 , and a rear face (or retention face)  57 , opposite to the front face, substantially normal to the Y direction, which is most visible in  FIG. 6   b.    
         [0050]    In the example presented, a through opening  58  is provided in a proximal region of the crown (i.e. close to the central plate). It extends radially in the crown  9 , and is positioned longitudinally between the retaining element  42  and the central plate  50 . Consequently, in certain angular sectors of the flange, the crown features an internal face that is purely cylindrical in the proximal and distal regions. In other angular sectors, they feature an opening in the proximal region then a retaining element in the distal region, positioned one after the other in the longitudinal direction when moving from the central plate to the front face. 
         [0051]    However, such openings are not essential to the implementation of the invention. 
         [0052]    The second flange  20  has the general form of a rigid disc, formed by stamping, which is fixed in this case to the seat back  4 . It comprises a central plate  59  extending substantially in a plane that is normal to the Y axis, and which has a front face  60  and a rear face  61  opposite. The latter may feature attachment patterns, for example formed by stamping, to attach it to the seat back  4 . 
         [0053]    The second flange also features a peripheral crown  22  comprising an internal face  62  that is globally circumferential around the Y axis, and has a toothed segment equipped with teeth  24 . An external face  63  is opposite the internal face, and has a smooth cylindrical geometry revolving around the Y axis, and with a radius that is substantially equal, slightly less than that of the internal face  52  of the crown  9  of the first flange. A front face  64  joins the internal  62  and external  63  faces, and extends for example normally to the Y axis. 
         [0054]    The second flange also features a cylindrical bore with a circular section extending along the main axis of rotation Y and forming a passage  28  for the command rod. 
         [0055]    The retaining elements  42  of the peripheral crown  9  of the first flange  10 , which protrude radially towards the centre, retain the second flange  20  in the first flange  10 , preventing relative translation of these two flanges along the Y axis whilst permitting their relative rotation around this axis. 
         [0056]    In the assembled position, the front face  64  of the crown  22  of the second flange  20  is opposite the front face  50  of the first flange. The peripheral part of the rear face  61  of the second flange is opposite the retaining face  57  of the first flange  10 . They are consequently situated directly opposite one another, with no intermediate parts or elements between them. The external face  63  of the crown  22  of the second flange  20  is opposite the internal face  52  and, where applicable, the openings  58  of the crown  9  of the first flange  10 . 
         [0057]    The actuation transfer element  30 , or “cam”, has three hooks  31 ,  32 ,  33  and three actuation surfaces designed to engage with each of the respective locking elements  11 ,  12 ,  13 . Each hook  31 ,  32 ,  33 , is provided to release the grains. 
         [0058]    The cam  30  is stationary to the rod and mobile in rotation around the main axis of rotation Y between a locked position and an unlocked position. 
         [0059]    The cam  30  engages with the locking elements  11 ,  12 ,  13  in a plane extending perpendicularly to the main axis of rotation Y, such that the cam  30  does not extend in the direction of the main axis of rotation Y between the locking element  11 ,  12 ,  13  and the first flange  10 , nor between the locking elements  11 ,  12 ,  13  and the second flange  20 , but engages radially to the main axis of rotation Y with the locking elements  11 ,  12 ,  13 . 
         [0060]    A spring  7  tends to bring the cam  30  back to the locked position. 
         [0061]    The locking elements  11 ,  12 ,  13  are positioned regularly (at 120°) in the first flange  10 . They each comprise a toothed segment  11   a ,  12   a,    13   a,  a guide portion  11   b ,  12   b,    13   b,  a release pin  11   c,    12   c,    13   c,  and an actuation portion  11   d,    12   d,    13   d.    
         [0062]    Each guide portion features a guide surface that is complementary to an external face of the respective guide element  14 ,  15 ,  16 . 
         [0063]    In the active position, the cam presses against the actuation surface  11   d,    12   d ,  13   d  of each of the locking elements  11 ,  12 ,  13 , via the thrust surfaces, in order to maintain the locking elements in the active position. 
         [0064]    In the active position of the locking elements, the toothed segments  11   a,    12   a ,  13   a  engage with the teeth  24  of the toothed crown  22 , in order to prevent the rotation between the first flange  10  and the second flange  20  around the main axis of rotation Y. 
         [0065]    The engagement between the guide portions  11   b ,  12   b,    13   b  and the guiding elements  14 ,  15 ,  16  enables a movement of the locking elements  11 ,  12 ,  13  in a plane that is normal to the Y axis between an active position and an inactive position. The faces of the locking elements  11 ,  12 ,  13  which are normal to the Y direction are in contact and slide on parallel front faces of the first and second flanges (Front face  39  of the first flange  10  and front face  60  of the second flange  12  as may be seen in  FIG. 3 ). In the inactive position of the locking elements, the toothed segments  11   a ,  12   a,    13   a  are distant from the teeth  24  of the crown  22 , which enables free rotation between the first flange  10  and the second flange  20  around the main axis of rotation Y. 
         [0066]    When the cam pivots from its locked position to its unlocked position from the action of the command rod (from the action of a user wishing to unlock the mechanism to adjust the relative orientation of the two flanges), the actuation surfaces disengage from the respective actuation surfaces  11   d,    12   d,    13   d  of the grains. Each of the retaining surfaces of the hooks  31 ,  32 ,  33  engage with the pin  11   c,    12   c ,  13   c  of a respective grain  11 ,  12 ,  13  to bring said respective grain to the inactive position progressively as the pin is inserted  11   c,    12   c,    13   c  inside the hook. 
         [0067]    When the user releases the handle, thus releasing the command rod  8 , the spring  7  moves the cam  30  towards its active position. The hooks  31 ,  32 ,  33  of the cam disengage again from the pins  11   c,    12   c,    13   c  of the respective grains, then the actuation surface of the cam solicits the respective grains from their inactive position to their active position previously described. During this movement, the grains are guided by the engagement of the guide surfaces, until they reach the locked position previously described. 
         [0068]    Even though this embodiment has been described in the context of a discontinuous adjustment mechanism with rotary grains, other embodiments may be envisaged by a person skilled in the art, provided that the two flanges are retained with one another in the Y direction, and are free to turn around this Y direction. For example, discontinuous mechanisms with sliding grains, or even continuous mechanisms with epicycloidal trains. 
         [0069]    One example of an embodiment of a manufacturing method will now be provided in references to  FIGS. 4 to 6   b . A second flange, as described above, is obtained for example by stamping. As may be seen in  FIG. 4 , a first flange  10  is provided, substantially as described above, except that the parties  66  designed to form the retaining elements  42  do not protrude radially towards the centre with respect to the internal face  52  of the crown  9 . For example, the crown  9  is provided as a perfectly hollowed cylinder, featuring the openings  58  mentioned previously. Such a creation may be made by stamping sheet metal, then making the openings  58 . If required, the openings may be made before stamping, in the suitable positions on the original metal sheet. 
         [0070]    Next, the two flanges are placed opposite one another, the front face  62  of the crown of the second flange  20  is opposite the front face  39  of the central plate of the first flange, and the external face  63  of the crown  22  of the second flange  20  is opposite the internal face  52 . The insertion of the second flange in the first one is possible due to the fact that the retaining elements at this stage do not protrude. Beforehand, care has been taken to place all of the active elements of the system (cam, grains, spring, and others where applicable) between the flanges. 
         [0071]    Next, as shown by the arrow A in  FIG. 6   b , the retaining elements are deformed, to move them radially inwards, in the direction of the Y axis, so that their rear retaining face  57  is opposite the rear face  61  of the second flange. This deformation is facilitated by the presence of the opening  58 . 
         [0072]    Where applicable, a deformation is made as shown by the arrow B in  FIG. 6   b , longitudinally along the Y axis in the direction of the front face  39  of the first flange to clamp the second flange with the retaining element, and reduce the longitudinal clearance.