FR2873634A1 - Articulation mechanism range for motor vehicle seat, has mechanisms with two connection units that are identical for all mechanisms and house locking, blocking and over-locking steps which are variable in number and/or form - Google Patents

Abstract

The range has articulation mechanisms comprising two connection units, where each unit is connected to a seat base and a backrest. The units are identical for all the mechanisms. A locking step (414a), a blocking step (414b) and an over-locking step (414c) are placed between the connection units to block the rotation of the connection units. The steps (414a-414c) are variable in number and/or form. Independent claims are also included for the following: (A) a process of manufacturing an articulation mechanism range (B) a motor vehicle seat.

Description

RANGE OF JOINT MECHANISM AND SEAT COMPRISING ONE

MECHANISM OF THIS RANGE

  The present invention relates to the mechanisms of articulation for a motor vehicle seat, the seats comprising such mechanisms, as well as to the manufacturing processes of these mechanisms.

  More particularly, the invention relates to a range of articulation mechanisms intended to allow an angular adjustment between two elements, these articulation mechanisms comprising: first and second rigid connecting members pivotally mounted relative to one another; other and intended to be respectively connected to the two elements to be adjusted, at least one of the first and second connecting members comprising at least a first locking surface extending over at least a portion of a circle centered on a central axis. rotation, - at least one grain, housed between the first and second connecting members, comprising a locking shoe adapted to engage the first locking surface, - and a control device adapted to move this grain between a locked position in which it cooperates via its locking shoe with the first locking surface, and an unlocked position e, in which its locking shoe is no longer engaged with the first locking surface.

  Document FR-A-2 462 127 describes an example of such a hinge mechanism.

  An articulation mechanism of this type is designed and defined to withstand a predefined resistance. This requires redefining, for example at its diameter and / or its interface with the other elements of the seat, each new articulation according to the desired resistance.

  An object of the invention is in particular to standardize, at least partially, the production of such mechanisms.

  For this purpose, according to the invention, there is provided a range of articulation mechanisms which, in addition to at least some of the features indicated above, is characterized in that the first and second connecting members are respectively identical for all mechanisms and are adapted to accommodate grains of variable number and / or of variable shape.

  Thanks to these arrangements, it is possible to obtain, for example, for a single hinge diameter, a wide range of resistance. For this purpose, it is sufficient to add or remove components such as grains, between the first and second connecting members.

  In various embodiments of the invention, one and / or other of the following provisions may be used: all the hinge mechanisms of the range comprise identical guides in number and in shape; these guides can take different forms depending on the range of joints; they may be guides on a control member, such as the bearing surfaces, hooks and cam surfaces described later in this document; they may be guides on a grain, such as the locking fingers and described later in this document; they may be guides on a connecting member, such as the reliefs, the guide surfaces and the ramps described later in this document; the range comprises at least one articulation mechanism with P grains and at least one articulation mechanism with N grains, with P greater than N; the range comprises a hinge mechanism in which at least one of the first and second connecting members comprises M guides, to guide the movement of N grains between their locked position and their unlocked position, with M greater than or equal to N ; the range comprises a hinge mechanism in which the control device comprises M guides, to guide the movement of N grains between their locked position and their unlocked position, with M greater than or equal to N; the articulation mechanisms of the range comprise first and second connecting members each comprising first and second locking surfaces, respectively; the first and second locking surfaces of each articulation of the range are superimposed in two distinct planes perpendicular to the axis of rotation; each articulation mechanism of the range comprises at least one grain with a first and a second locking pad, each cooperating respectively with the first and second locking surfaces; each hinge mechanism different from the range comprises a different number of similar grains, angularly distributed around the axis of rotation, the control device being adapted to selectively bring the grains into engagement with the first and second locking lands; each articulation mechanism of the range comprises grains whose first and second locking shoes succeed each other, in different planes, along an arc of a circle centered on the axis of rotation; and - at least two joints in the range have a distinct number of grains between 1 and 6.

  According to another aspect of the invention, this relates to a method of manufacturing a range of articulation mechanisms intended to allow an angular adjustment between two elements, in which process, for each articulation mechanism: first and second rigid connecting members pivotable relative to each other and intended to be respectively connected to the two elements to be adjusted, at least one of the first and second connecting members comprising at least a first locking surface extending over at least a portion of a circle centered on an axis of rotation, - at least one grain is housed between the first and second connecting members, this grain having a locking shoe adapted to engage with the first locking bearing, - and mounted between the first and second connecting members a control device adapted to move the grain between a locked position, in which it co operates via its locking shoe with the first locking surface, and an unlocked position, in which its locking shoe is no longer engaged with the first locking surface, characterized in that the first and second linking members are respectively identical for all the mechanisms and are adapted to accommodate grains of variable number and / or of variable shape.

  In this case, it is possible, when carrying out the method according to the invention, to produce articulation mechanisms whose number of grains is between 1 and 6.

  According to another aspect, the invention also relates to a vehicle seat comprising a backrest and a seat hinged by means of a hinge mechanism according to the present invention.

  Other aspects, objects and advantages of the invention will become apparent from the description of several of its embodiments.

  The invention will also be better understood with the aid of the drawings, in which: FIG. 1 is a diagrammatic view of a seat whose backrest is adjustable in inclination by means of at least one articulation mechanism according to a first range of joints according to the invention, - Figure 2 is a detailed view showing a first articulation of the first range according to the invention for the angular adjustment of the seat back of Figure 1, - Figure 3 is a view in section along the line III-III of Figure 2, - Figure 4 is an exploded view of the articulation mechanism 20 of Figure 3 - Figure 5 is a view similar to Figure 4, seen in the direction V FIG. 6 is an exploded view showing the detail of the locking device of the articulation mechanism of FIG. 4, seen in the same direction as FIG. 4; FIG. 7 is a view similar to FIG. FIG. 6, seen in the same direction as FIG. 8 and 9 are cross-sectional views of the hinge mechanism of FIG. 3, respectively along lines BB and CC of FIG. 3, when the hinge mechanism is locked, FIGS. 10 and 11 are views. similar to FIGS. 8 and 9 respectively, showing the articulation during an adjustment of the inclination of the backrest, FIGS. 12 and 13 are views similar to FIGS. 8 and 9, respectively, while folding the backrest forwards in order to allow easier access to the space behind the seat, - Figure 14 is a sectional view along the line DD of Figure 3, in the position of Figures 12 and 13, - Figures 15 to 24 are respectively views similar to Figures 4 to 13, for another articulation of the first range according to the invention, - Figure 25 is a schematic view of a vehicle seat according to a first articulation of a second range of articulation according to the invention, - Figure 26 is a seen In axial section, similar to FIG. 3, in the embodiment of the invention of FIG. 25, FIGS. 27 and 28 are sectional views along lines AA and BB, respectively, of FIG. FIG. 29 is a detailed view of one of the grains of the hinge mechanism of FIGS. 27 to 28; FIGS. 30 and 31 are perspective views of the grain of FIG. 29, views in two opposite directions, - Figures 32 and 33 are partial sectional views of the right and left parts of one of the grains of the hinge mechanism of Figures 26 to 28, the sections being taken respectively along lines AA and B-B of Fig. 26, during tilt adjustment of the seat back, - Figs. 34 and 35 are views similar to Figs. 32 and 33, respectively, showing the grain when it returns to engagement at the end of recline adjustment of the backrest, FIG. 36 is a sectional view of According to a third embodiment of the invention, FIG. 37 is an internal view of the mechanism 5 of FIG. 36 without its fixed flange or crimped metal ring, FIG. FIG. 39 and 40 are exploded perspective views of a hinge mechanism according to a fourth embodiment of the invention, seen in two opposite directions, FIG. 41 is an axial sectional view of the articulation mechanism of FIGS. 39 and 40; FIGS. 42 to 44 are sectional views respectively along the lines BB, CC and DD of the articulation mechanism of FIG. rest position, - Figures 45 and 46 are respectively views similar to Figures 43 and 44 showing the articulation during a tilt adjustment of the folder, Figure 47 schematically shows in perspective a connecting member of a ci nth range of joints, - and Figures 48 to 52 show respectively, schematically in perspective, a different articulation of the fifth range of joints.

  In the different figures, the same references designate identical or similar elements.

  As shown diagrammatically in FIG. 1, the invention relates to a vehicle seat 1, in particular (but not exclusively) a front seat of a motor vehicle, which comprises, on the one hand, a seat 2 mounted on the floor 3 of the vehicle, and on the other hand, a backrest 4 pivotally mounted on the seat 2 about a transverse horizontal axis Y, by means of at least one articulation mechanism 5.

  The hinge mechanism 5 can be controlled for example by means of a handle 6 which can be actuated in the direction 6a to unlock the backrest 4 pivoting about the Y axis. The backrest 4 can furthermore comprise an actuator member. additional maneuver 7 - handle or other - which can be arranged for example in the upper part of the backrest 4 and which is connected to the hinge mechanism by a cable 8 such as a sheathed cable.

  As shown in FIG. 2, one end of the core 8a of the sheathed cable 8 can be fixed for example to a lever 9 integral with the handle 6, the sheath 8b of the cable being furthermore fixed to the backrest frame 4. The lever 9 may for example be arranged so that the actuation of the handle 7, causing a pull on the web 8a of the cable 8, moves the lever 9 of the handle 6 in an angular direction 9a opposite the direction 6a mentioned above. .

  As represented in FIGS. 3 to 5, the hinge mechanism 5 may comprise, for example: a first rigid link member, for example a generally disk-shaped metal flange centered on the axis of rotation Y, this first connecting member being fixed for example to the frame of the backrest 4 (where appropriate, the frame of the seat 2), a second rigid connecting member 11, for example a metal flange in the general shape of disc centered on the Y axis, this second connecting member being fixed for example to the frame of the seat 2 (or, where appropriate, to the backrest frame 4), a metal ring 12 set on the periphery of the first and second connecting members 10, 11 allowing a relative pivoting between these two connecting members around the Y axis (the crimped crown 12 could however be replaced by any other means for maintaining the two connecting members 10, 11 the against each other by letting them free rotation in rotation about the axis Y), - and a locking device 13 adapted to selectively block or unlock the two connecting members 10, 11 in relative rotation around the axis Y. As shown in more detail on the Figures 4 to 7, the locking device 13 comprises at least one rigid grain 14 in the general shape of a circular arc. In the first example of a range of joints according to the invention described below, a first articulation comprises for example three grains 14 angularly distributed at 120 from each other around the Y axis. The grains 14 are controlled by a device 15 (see also Figures 8 and 9) which, in the example shown, comprises: - a rigid central shaft 16 which is integral with the handle 6 and the lever 9 (see Figure 3), - first and second cams 17, 18 which may for example be superposed flat sheet metal parts, respectively extending in first and second distinct planes perpendicular to the axis of rotation Y, the first and second cams being resiliently biased respectively, in the second direction angular 9a for the first cam 17 and in the first angular direction 6a for the second cam 18.

  The elastic stresses of the cams 17, 18 may be obtained for example by first and second springs 19, 20 for example spiral springs of substantially the same stiffness, whose inner end is secured to the shaft 16 and whose end outer bears for example on a protruding pin 17a, 18a of the corresponding cam. The fastening of the inner end of the springs 19, 20 with the shaft 16 can be obtained for example by providing the shaft 16 with a non-cylindrical shape of revolution and by conforming the radially inner portion of the springs 19, 20 that this inner part comes to fit on the perimeter of the tree 16.

  In the example shown in the drawings, the first connecting member 10 comprises a first locking surface 21, circular and oriented radially inwards (in the example considered here, the first locking surface 21 forms a complete circle, but it could form only one or more arcs centered on the axis of rotation Y).

  The first locking surface 21 is disposed in the plane of the first cam 17, and each of the grains 14 comprises a first locking pad 22, arranged in the same plane, which is adapted to engage the first locking surface 21 thereby immobilizing the grains 14 with respect to the first connecting member 10.

  In the example considered here, the first locking surface 21 is a toothing oriented radially inwards and the first locking pads 22 of the grains are in the form of teeth oriented radially outwardly. Optionally, the first locking surface 21 and the first locking pad 22 could also be constituted by non-toothed frictionally cooperating surfaces.

  Moreover, as shown in FIG. 4, the second connecting member 11 comprises at least one second locking surface 23, in this case six locking surfaces 23 angularly distributed at 60 from one another in the example considered here. These second locking surfaces 23 have circular shapes (more particularly, in an arc of a circle) centered on the axis Y, and for example of the same diameter as the first locking surface 21.

  As shown in FIG. 9, the second locking surfaces 23 are oriented radially inwards, in the plane of the second cam 18. They are therefore immediately adjacent to the first locking surface 22, in the direction of the axis Y. The grains 14 each comprise a second locking pad 24 which is also arranged in the plane of the second cam 18 and which is adapted to engage one of the second locking surfaces 23 of the second connecting member 11. On the same grain 14, the second locking shoe 24 is angularly offset relative to the first locking shoe 22, and it is arranged in such a way that there is no axial overlap between the two locking shoes 22, 24.

  In the example considered here, the second locking surfaces 23 and the second locking shoes 24 are respectively radially inwardly and radially outwardly oriented teeth, but it could also be, if appropriate, to surfaces cooperating by friction.

  As can be seen in FIG. 4, the second connecting member 11 also comprises circular guide surfaces 25 centered on the Y axis and oriented radially inwards. Each of these guide surfaces 25 extends angularly, in the angular direction 6a, between a stop 27 projecting radially inwards and a notch 26 extending radially outwards, the notch 26 being adjacent to an another stop 27 (the notches 26 and the abutments 27 are also each 3 in the example considered here).

  The guide surfaces 25, the notches 26 and the stops 27 cooperate with the grains 14, for example with protruding pins 28 carried by each of the grains 14 facing the locking shoe 24 (see Figure 5). The pins 28 are normally engaged in the notches 26 to allow the second locking pads 24 grains to be in engagement with the second locking surfaces 23 of the second connecting member.

  As can be seen in FIGS. 6 and 7, each of the grains 14 may, if necessary, be constituted in the form of a folded and cut sheet metal plate, comprising first and second flat portions 29, 30, disposed respectively in the planes of the first and second cams 17, 18 and respectively carrying the first and second locking shoes 22, 24, the second flat portion 30 further bearing the pin 28. The first and second flat portions 29, 30 of each grain 14 are in further connected to one another by a fold 31.

  Moreover, each grain 14 may have, on its radially inner edge, a central notch 32 flanked by two bearing surfaces 33, 34 respectively belonging to the flat portions 29, 30. Each bearing surface 33, 34 is itself framed by two unlocking fingers 35, 36 extending diagonally radially inwards.

  The first and second cams 17, 18 also have outer edges identical or similar to each other, but of opposite angular orientation. More particularly, the first cam 17 comprises a series of hooks 37 extending diagonally radially outwardly and angularly in the direction 6a. These hooks may be for example six in number and angularly distributed at 60 from each other about the Y axis. The second cam 18 has hooks 38 similar to the hooks 37, but oriented in the angular direction 9a.

  Moreover, each hook 37 of the first cam 17 is associated with a cam surface 39 disposed immediately at the rear of the hook in the angular direction 6a, each hook 37 being separated from the next cam surface 39 in the opposite direction. angular 6a, by a notch 41 which extends radially inwards in the cam 17.

  The second cam 18, for its part, also has cam surfaces 40 and notches 42, each cam surface 40 being disposed immediately behind a hook 38 in the angular direction 9a and separated from the preceding hook 38 (FIG. always in the angular direction 9a) by an indentation 42.

  The cam surfaces 39, 40 are adapted to bear respectively against the bearing surfaces 33, 34 of the grains 14 so that the first and second locking pads 22, 24 of these grains 14 engage respectively with the first and second locking surfaces 21, 23, in the rest position of the articulation mechanism.

  The hooks 37, 38 of the cams penetrate into the notches 32 of the grains, and the unlocking fingers 35, 36 of the grains penetrate respectively into the indentations 41, 42 of the two cams.

  Finally, the cams 17, 18 internally comprise indentations in an arc of an arc, respectively 43, 44 (see FIGS. 6 and 7), in which at the same time at least one actuating finger 45 integral with the shaft 16 and protruding radially towards the outside from the shaft 16. In the example shown in the drawings, the shaft 16 has two actuating fingers 45, and each cam 17, 18 has two arcuate notches 43 and 44 respectively. The notches 43, 44 of the two cams are angularly offset relative to each other, in the rest position of the articulation mechanism, and make a link with lost motion with the actuating fingers 45.

  The angular displacement between the two cams 17, 18 is further limited by an additional link independent of the actuating finger 45. In the example shown in the drawings, this additional connection is formed by at least one abutment pin 46 formed in the second cam 18 and protruding axially towards the first cam by penetrating into an arcuate recess 47 of the first cam 17. More particularly, the second cam 18 may comprise for example two abutment pins 46 diametrically opposite to the Y axis, and the first cam 17 then comprises two corresponding arcuate notches 47, these arcuate notches communicating with the notches 43 which receive the driving fingers 45, but the notches 47 have a radius slightly less than notches 43. The abutment pins 46 guarantee in particular that the two cams 17, 18 can not be placed simultaneously. and in their unlocking position even in case of misuse of the seat, so that the grains 14 are always in engagement with at least one of the flanges 10, 11.

  The locking shoes 22, 24 are, in the example considered here, arranged in the same cylindrical surface of revolution centered on the axis Y and defined by the pitch circle of the teeth constituting the locking pads 22, 24.

  This cylindrical surface has a slightly smaller radius, for example about 1 to 5%, with respect to the radius of the first and second locking surfaces 21, 23 (also defined as the radius of the pitch circle of the teeth of the locking surfaces 21, 23 in the example considered here). It is thus possible for each grain 14 to be positioned at best, by a slight rotation in a plane perpendicular to the Y axis, with respect to the first and second locking surfaces 21, 23. For example, this difference in radius can make it possible to allow a slight rotation of 0.3 to 1 of each grain 14 while leaving the first and second locking pads 22, 24 respectively engaged with the first and second locking lands 21, 23. When the locking lands and the locking pads are formed by teeth, this characteristic allows in particular that these teeth come into mutual engagement in the best possible conditions, eliminating any angular play between the first and second connecting members, and ensuring an extremely strong locking between the first and second connecting members. This blocking is all the more resistant that, when the articulation mechanism must take a particularly high torque, for example when the vehicle in which the seat is installed is an accident, the grains 14 work in shear to directly transmit the forces between the first and second locking lands 21, 23.

  The device that has just been described operates as follows.

  In the rest position of the articulation mechanism, as represented in FIGS. 8 and 9, the first and second locking shoes 22, 24 of each of the grains are respectively engaged with the first and second locking surfaces 21, 23 belonging to each other. respectively to the first and second connecting members 10, 11. The grains are held in these positions by pressing the cam surfaces 39, 40 of the first and second cams 17, 18 respectively against the bearing surfaces 33, 34 of the grains 14, the cams 17, 18 being held in their locking position of FIGS. 8 and 9 under the effect of the elastic biasing of the springs 19, 20.

  As shown in Figures 10 and 11, when a user wishes to adjust the inclination of the backrest 4, it actuates the handle 6 in the angular direction 6a, so that the actuating fingers 45 abut at one end of the notches 43 of the first cam 17, by driving it in the unlocking position in the angular direction 6a until the hooks 37 of the first cam (or at least three of these hooks for this example of articulation) s engage the unlocking fingers 35 of the grains 14 by rotating these grains 14 around their second locking shoe 24, which remains in engagement with the corresponding second locking surface 23.

  The grains 14 thus arrive in a first erased position where their first locking pad 22 does not interfere with the first locking surface 21.

  The arcuate notches of the first and second cams are angularly offset so that the drive fingers 45 do not interfere with the second cam 18 during this movement, so that the cam surfaces 40 (more exactly, three cam surfaces 40, in the example considered here) remain in abutment against the bearing surfaces 34 of the grains 14, ensuring that the second locking shoes 24 remain in engagement with the second locking surfaces 23. pivoting of the grains 14 is facilitated by the fact that

  first and second locking shoes 22, 24 have a radius close to or equal to this radius of the first and second locking surfaces 21, 23. The radius of the bearing surfaces 22, 24 may be slightly less than the radius of the bearing surfaces 21, 23. pivoting movement is also facilitated by the shapes of the angular ends of the pads 14, which are adapted to avoid any interference between the grains 14 and the connecting members 10, 11 during the pivoting of the grain 14 around one or the other from these ends.

  When the articulation mechanism is in the position of FIGS. 10 and 11, that is to say with its first cam 17 in the unlocking position and its second cam 18 in the locked position, the backrest 4 of the seat can be tilted manually by the user, generally acting against an elastic bias that tends to rotate the backrest 4 forward.

  Optionally, it can be ensured that the first cam 17 is in the unlocking position as long as the flange 10 is not in a predefined angular position with respect to the flange 11. For this purpose, it is possible, for example, to provide, on the inside face the flange 10, a circular guide surface 50 in an arc (Figure 5) which extends angularly on either side of a larger diameter area 51. One of the grains 14 comprises a pin 52 axially protruding (Figure 6), which is in the area 51 when the flange 10 is in the angular range where the cam 17 can come into the locking position and where the grains 14 can lock on the toothing 21 of the flange 10.

  However, when the pin 52 is in correspondence with the guide surface 50, it prevents the first locking pads 22 to lock on the toothing 21 and the cam 17 is thus maintained in normal unlocking position. In this position, the abutment pins 46 prevent, by abutting on one of the edges of the notches 47, an offset of the cam 17 relative to its unlocking position, which could cause noises licking teeth during relative rotation of the flanges 10, 11.

  Furthermore, when a user wants to access the space at the rear of the seat 1, he can fold the backrest 4 fully forward, by actuating the handle 7 shown in Figure 1, which rotates the lever 9 and the shaft 16 in the angular direction 9a, as shown in FIGS. 12 to 14.

  During this movement, the drive fingers 45 of the shaft 16 do not interfere with the first cam 17, due to the angular offset between the notches 43, 44, so that the first cam 17 remains in its position and locks the first locking pads 22 in engagement with the first locking surface 21 (FIG. 12).

  On the other hand, as can be seen in FIG. 13, the hooks 38 of the second cam (or more exactly three of the hooks 38 in the present example) engage the unlocking fingers 36 of the seeds 14 by rotating the grains 14 The grains 14 thus pass into the second erased position visible in FIG. 13, where the second locking pads 24 no longer interfere with the second locking surfaces 23.

  In addition, during this movement, as can be seen in FIG. 14, the pawns 28 of the grains are disengaged from the notches 26 of the second connecting member 11 and, as soon as the folder is folded forwards, these pins 28 abut against the guide surfaces 25, which prevents the second locking pads 24 grains 14 to engage with the first locking lands 21. During the folding movement of the backrest forward, the pins 28 remain in abutment against the guide surfaces 25 while the entire control device 15 moves with the grains 14 and the first connecting member 10 in rotation about the axis Y, with the backrest 4.

  When the user wishes to raise the seat back 4 after having folded forward, this movement results in angular displacement of the grains 14 in the opposite angular direction to the direction 9a, until the pins 28 come hitting the stops 27 which define the notching position of the grains 14 relative to the second connecting member 11. The pins 28 then engage in the notches 26, which allows the second locking pads 24 grains 14 to come into engagement with the second locking lands 23.

  It will be noted that when the pins 28 strike the abutments 27, the grains 14 work in abutment against the first locking surface 21, so that the first locking pad 22 of each grain 14 is not likely to decompose.

  This ensures that the backrest 4 of the seat is re-locked exactly in the same angular position as that which it occupied before the actuation of the handle 7.

  At the end of relocking, the grains are self-organizing due to the small clearance allowed between the grains 14 and their respective cams and locking surfaces. This low clearance corresponds to a slight rotation, of at least 0.3 degrees, of the grains in a plane perpendicular to the axis of rotation Y. This provides an optimized locking of the locking pads 22, 24 with the locking surfaces 21, 23 corresponding.

  A second articulation of the first range of joints according to the invention is shown in FIGS. 15 to 18. For this second articulation, the first and second connecting members 10, 11, the crimped crown 12 and the control device 14 are identical to those described above, and will not be described again here.

  In this first range of joints, the locking device 13 is identical to all the joints. In particular, there are provided on the first 17 and second 18 cams bearing surfaces 33, 34 and unlocking fingers 35, 36 constituting guides, sufficient in number to guide a variable number of grains 14.

  This second articulation is distinguished from that previously described in that it comprises three additional grains 14, identical to the grains 14 already described, except that they do not have pins 28. There are therefore three grains 14 with pions 28 and three grains 14 without pawns 28.

  In this second articulation, it takes advantage of the fact that the grains 14 comprise two flat portions 29, 30 arranged in two distinct planes, at least partially superimposing the first and second flat portions 29, 30 of two adjacent grains. When the first and second cams 17, 18 are in the locked position, as shown in FIGS. 19 and 20, the six cam surfaces 39, 40 are in respective abutments on the bearing surfaces 32, 34 of the six grains. In this position, a blocking of an exceptional resistance is obtained between the first and second connecting members 10, 11. In the first example of the range according to the invention described here there is at least one three-grain articulation and at least one six-grain joints. Between these two articulations alone differ the number of grains and the shape of certain grains. The resistance of the three-grain joint is about 3000 N, that of the six-grain joint is about 6000 N.

  Moreover, as shown in FIGS. 21 and 22, when a user actuates the handle 6 in the angular direction 6a, the six hooks 37 of the first cam 17 engage on the six unlocking fingers 35 of the grains 14, so that the six grains move in their first erased position where their first locking pad 22 no longer interferes with the first locking surface 21 (see FIG. 21).

  As represented in FIG. 22, the cam surfaces 40 of the second cam then remain in abutment against the bearing surfaces 34 of the grains 14 while maintaining the second locking pads 24 of the grains 14 in engagement with the second locking surfaces 23 .

  Also, as shown in FIGS. 23 and 24, when the handle 7 is actuated, the first cam 17 remains stationary while maintaining the first locking shoes 22 in engagement with the first locking surface 21, while the hooks 38 of the second cam 18 engage on the unlocking fingers 36 of the six grains 14, so that the grains 14 pivot about their first locking pad 22 to their second erased position where the second locking pads 24 do not interfere with the second locking lands 23. During the following pivoting movement of the backrest 4, only the three grains 14 which comprise pins 28 cooperate with the guide surfaces 25, but these three grains hold the second cam 18 in the unlocked position , so that all the grains 14 remain in their second erased position as long as the file 4 has not been raised to its previous angular position settled.

  In the second example of a range of joints according to the invention, represented in FIGS. 25 to 35, the seat 101 again includes a seat 102 carried by the floor 103 of the vehicle, and a backrest 104 which is pivotally mounted around the seat. Y axis of rotation by means of a hinge mechanism 105. The hinge mechanism is adapted to selectively lock or unlock the backrest 104 in rotation relative to the seat 102, and is controlled by a handle 106 actuable in an angular direction 106a.

  As shown in FIG. 26, the hinge mechanism 105 comprises, for example: a first rigid connecting member 110, for example a generally disc-shaped metal flange centered on the axis of rotation Y, this first member connection being fixed for example to the frame of the backrest 104, - a second rigid connecting member 111 for example a generally disk-shaped metal flange centered on the Y axis, this second connecting member being fixed for example to the armature of the seat 102, a metal ring 112 crimped around the periphery of the first and second connection members 110, 111 allowing relative pivoting between these two connecting members about the Y axis (the crimped crown 112 could, however, be replaced by any other means to maintain the two connecting members 110, 111 against each other by leaving them free to rotate about the axis Y), and a blocking device 113 adapted for selectively bl oquer or unblock the two connecting members 110, 111 in relative rotation about the axis Y. As shown in Figures 27 and 28, the locking device 113 comprises at least one grain 114 rigid. For example, according to a first articulation of this second range of joints, it comprises three grains 114 angularly distributed at 120 from each other about the Y axis. The grains 114 are controlled by a control device 115, which in the example shown, comprises: - a rigid central shaft 116 which is integral with the handle 106, - and a cam 117 which may for example be in the form of a cut sheet metal plate secured to the shaft 116 and extending in a plane perpendicular to the axis of rotation Y. The cam 117 has, at its outer periphery, at least one cam surface 139 projecting radially outwardly. In the example shown here, the cam 117 has six cam surfaces 139, three of which bear against the bearing surfaces 133 of the respective grains 114, so as to move the grains 114 radially outwardly.

  The cam 117 is resiliently biased towards its locking position shown in FIGS. 27 and 28, for example by means of a spiral spring (not shown) whose inner portion can be secured to the shaft 116 (for example by interlocking the inner portion of the spring on a non-cylindrical portion of revolution of the shaft 116) and whose outer end is attached to a portion of the second connecting device 112.

  The grain 114, meanwhile, can be made in the form of a piece of sheet metal cut and stamped, comprising: - a body 118, - a tail 119 extending the body 118 radially inward and having the surface of support 133, - a first flat portion 129 extending in a first plane perpendicular to the Y axis and carrying a first locking pad 122 oriented radially outwards, this first locking pad being adapted to engage with a first locking lug 121 (forming a complete circle or an arc) facing inwardly and secured to the first connecting member 110, - a second flat portion 130 extending parallel to the first flat portion 129 but shifted of the latter angularly with respect to the axis of rotation Y, the second flat portion 130 extending in a second radial plane distinct from the first plane, without axial overlap between the first and second I flat portions 129, 130, and the second flat portion 130 carrying a second locking pad 124 oriented radially outwardly and adapted to engage a second locking surface 123 circular (more particularly, arcuate) oriented radially inwards and secured to the second connecting member 111.

  As shown in FIG. 28, the second connecting member 111 comprises six second locking lands 123. This possibly makes it possible to accommodate six grains in a second articulation mechanism of the range of joints described here. But in the case illustrated, only three of these second locking surfaces 123 are used when the hinge mechanism comprises only three grains 114. The second locking surfaces 123 are immediately adjacent to the first locking surface 121 in the direction of the Y axis. Each grain 114 is slidably guided, in the radial direction R passing through the tail 119 of this grain, by guides comprising: - reliefs 120 formed in the second connecting member 111, these reliefs 120 flanking with play the tail 119 of the grain, and the reliefs 120 may for example be in the form of two ribs per grain, converging towards each other radially outward, arranged symmetrically with respect to the direction R, - and two guide surfaces 125, 126 oriented parallel to the direction R and arranged in the second connecting member 111, these two guide surfaces coming opposite the two edges end 127, 128 of the second flat portion 130 of the grain.

  The guide surfaces 125, 126 and the end edges 127, 128 are shaped to allow a certain angular clearance of the grain 114 in a plane perpendicular to the Y axis. In addition, the first and second annular lands 121, 123 may have the same radius R1 centered on the Y axis, while the first and second locking pads 122, 124 may have the same second radius R2 slightly lower, for example from 1 to 5%, relative to the radius R1, so to allow the already described pivoting movement of the grains 14.

  When the locking surfaces 121, 123 and the first and second locking shoes 122, 124 are formed by teeth, the radius R 1 is that of the pitch circle of the teeth forming the locking surfaces 121, 123, and the radius R2 is that of the pitch circle of the teeth forming the first and second locking shoes 122, 124.

  The grain 114 is self-positioned on the first and second locking surfaces 121, 123, with a limited rotation amplitude of the grain, for example from 0.3 to 1, in particular of the order of 0.5.

  This self-positioning of the grain ensures that the first and second locking shoes 122, 124 come into perfect engagement with the first and second locking surfaces 121, 123 when the cam 117 is in the locking position, which guarantees maximum mechanical strength of the mechanism articulation relative to the high stresses of rotation, such as those that occur when the vehicle in which is installed seat 101 is an accident.

  The device that has just been described operates as follows.

  When the handle 106 is actuated in the direction 106a, it drives with it the cam 117, so that the grains 114 can move radially inwards, as shown in FIGS. 32 and 33. The user of the seat can then adjust the inclination of the backrest by manually acting on it.

  It will be noted that the movement of the grains 114 radially inwards can be obtained: either by simple cooperation between the first locking surface 121 and the first locking pad 122 of the grain, for example by camming of the teeth carried by these elements, either by elastic means biasing the grains radially inwards, or by using a control plate (not shown) provided with cutouts cooperating by cam effect with projecting pins 131 formed on the grains, for example according to the principles described in document FR-A-2 740 406 (according to the principles also described in this document, the first connecting member 110 may optionally comprise, in certain angular ranges, guiding surfaces cooperating with an additional pin 132 of the grains , to prevent the first locking pad 122 from engaging the first locking surface 121 in certain p angular distances).

  As shown in FIGS. 34 and 35, when the user releases the handle 106 after having actuated it, one of the locking shoes 122, 124 begins to fully engage with the corresponding locking surface 121, 123, Another locking shoe - in this case, the locking shoe 122 - is not fully engaged with the corresponding locking surface 121. However, thanks to the slight possible rotation of the grain 114, it self-positions and moves angularly until the first locking shoe 122 fully engages the first locking surface 121, while the second shoe locking 124 remains engaged with the second locking surface 124, which ensures a free play and very high resistance between the first and second connecting members.

  In this second example of a range of joints according to the invention, it is possible to obtain several joints, each with a different resistance, by changing only the number of grains. In this particular case, one can have for example two, three or six grains without changing any other element of the joint.

  A third example of a range of joints according to the invention, represented in FIGS. 36 to 38. In this range, the articulation mechanism 5 comprises first and second rigid connecting members 10, 11, for example in the form of flanges. circular metal, which may optionally be interconnected by a crimped metal ring 12 and which delimit a closed housing containing a locking device 13 adapted to selectively lock or unlock the two connecting members 10, 11 in relative rotation around the l Y axis. The locking device 13 comprises at least one rigid grain 214 in the general shape of an arc of circle, controlled by a control device 15 which, in the example shown, comprises a rigid central shaft 16 integral with a handle (not shown) accessible outside the seat, and a single cam 17 identical or similar to the first or second cam 17 or 18 previously described for the artic ulation of Figures 1 to 14.

  The cam 17 is urged elastically in the angular direction 17a, for example by means of a spiral spring (not shown) which is wound around the shaft 16, one end of which is secured to the shaft 16 and whose another end is secured to the second connecting member 11.

  The cam 17 comprises, on its periphery, at least one hook 37 and a cam surface 39. The cam surface 39 is adapted to rest on a bearing surface 233 of the grain 214 as long as the shaft 16 does not fit. is not rotated, keeping the seed 214 in the lock position. The hook 37 is adapted to engage on an unlocking finger 235 belonging to the grain 214 when the shaft 16 is rotated in the opposite direction of the direction 17a, so as to then move the grain in the unlocked position.

  As shown in FIGS. 37 and 38, the grain 214, for its part, may be in the form of a substantially flat sheet metal plate which extends mainly in the same plane as the cam 17 and in the plane of a circular toothing 21, centered on the axis of rotation Y and oriented radially inwards, formed in the first connecting member 10.

  The grain 214 has, at one of its angular ends, a toothing 222 oriented radially outwards and adapted to engage the toothing 21, and at its other angular end, said grain 214 has a protruding pin 240 which protrudes axially towards the second connecting member 11 and enters a hollow housing 241 formed in the second connecting member.

  The pin 240 and the housing 241 respectively have corresponding shapes in half-moons, with: a smooth portion in the form of a circular arc of small radius, disposed towards the axis of rotation Y and concavity oriented radially towards the outside, and a toothed portion disposed radially outwardly, respectively forming a second toothing 224 of the grain 214 and a toothed locking surface 223 of the second connecting member 11, the second toothing 224 and the locking surface 223 respectively presenting arcuate shapes centered on the Y axis, with a slightly lower pitch radius (eg about 1 to 5%) for the second toothing 224 of the grain with respect to the toothed locking surface 223. second toothing 224 is permanently engaged with the locking bearing 223.

  The pin 240 of the grain 214 is also mounted with a certain radial clearance, for example between 3 / 10kme and 4 / 10th of a mm, in the housing 241 corresponding.

  With these provisions, the grain 214 can pivot slightly around the pin 240 for example with an amplitude of about 2 degrees, which is sufficient to move the grain between on the one hand the locking position shown in Figures 36 and 37, where the toothing 222 of this grain is engaged with the toothing 21 of the first connecting member 10, and secondly, an unlocking position where said second toothing 222 is no longer in engagement.

  Furthermore, the first connecting member 10 may have on the inner face, a guide flange 242 which, in certain relative angular positions of the connecting members 10, 11, cooperates with a pin 243 of the grain 214 to prohibit this grain of switch to the lock position.

  At the end of relocking, the grains are self-positioning on the locking surfaces, thanks to the fact that a slight rotation is allowed, in a plane perpendicular to the axis of rotation Y. In this range, it is possible to vary the number of grains 214 from 1 to 6 for example, by adding or removing grains 214 identical to that described above, the other elements of the joint remaining the same.

  A fourth example of a range of joints according to the invention is illustrated in FIGS. 39 to 46. An articulation of this range is similar to that of FIGS. 15 to 24 and will therefore not be described again in detail hereinafter.

  With this fourth range of joints according to the invention, the seat 1 may comprise for example a single control handle 6 for controlling the articulation mechanism 5, which again comprises: - first 10 and second 11 connecting members similar to those of Figures 15 to 24, - a crimped metal ring 12 or other means of attachment between the connecting members 10, 11, - and a locking device 13 adapted to selectively block or unlock the two connecting members 10, 11 in relative rotation about the Y axis. The locking device 13 comprises at least one rigid grain 14 in the general shape of a circular arc. In the example considered here, the locking device 13 comprises six rigid grains angularly distributed at 60 from each other around the Y axis and are controlled by a control device 15 comprising a central shaft 16, a cam 317 and a control mask 318 joined together (for example by interlocking) and resiliently biased in rotation in the direction 9a by a spring 319, for example a spiral spring whose inner end is secured by interlocking on the shaft 16 and of which the outer end 319a is hooked for example on a pin 319b of the second connecting member 11. The cam 317 and the control mask 318 can be made in the form of flat sheet metal parts, cut and stamped.

  The grains 14 have a general shape similar to that of the grains of Figures 15 to 24, and each comprise two locking shoes 22, 24 for example in the form of teeth, which are offset in two separate planes, the first shoe of locking 22 of a grain being superimposed on the second locking pad 24 of the adjacent grain. The first locking pads 22 of the grains are thus arranged in the plane of the first locking surface 21 of the first connecting member 10, so as to cooperate with this locking surface, in this case by meshing, and the second pads 24 are arranged in the plane of the second locking surfaces 23 of the second connecting member 11 and are adapted to engage therewith.

  Unlike the embodiment of Figures 15 to 24, the second connecting member 11 does not include the guide surfaces 25, the notches 26 and stops 27, and the grains do not have the protruding pins 28. Moreover, in the embodiment of FIGS. 39 et seq., one grain out of two comprises a projecting pin 52 (FIG. 39). The three protruding pins 52 of the set of grains 14 cooperate respectively with three guide surfaces 50 in an arc of a circle, centered on the axis Y and arranged inside the first connecting member (FIG. 40), to prohibit the locking of the first locking pads 22 on the first locking surface 21 in certain relative angular positions of the connecting members 10, 11, while this locking is allowed by zones 51 of larger diameters formed in the first connecting member 10 ( see Figure 42) when the pins 52 are not facing the guide surfaces 50.

  Moreover, as shown in FIGS. 43 and 44, the radially inner portions of the grains 14 are made differently from those of the articulation of FIGS. 15 to 24. Indeed, in the fourth range of joints according to the invention, the first portion 29 of each grain, which carries the first locking pad 22, comprises a support edge 333 on which is pressed a cam surface 339 of the cam 317. At its end opposite the second portion 30, the first portion 29 each grain has no unlocking fingers, but only a notch 333a which is connected to the bearing edge 333 by a shoulder 333b angularly oriented in the direction 9a.

  Furthermore, as shown in FIG. 44, the second portion 30 of each grain comprises an unlocking finger 36 similar to that already described for the variant of FIGS. 15 to 24 and a bearing surface 34 also similar to that previously described. this bearing surface 34, however, preferably having a convex shape with a convexity turned radially inwards.

  Each bearing surface 34 is, at rest, respectively adjacent to a projecting cam edge 337 formed at the periphery of the control mask 318. The control mask 318 thus comprises, in the example considered here, six cam edges 337. In the rest position shown in FIGS. 42 to 44, the cam surfaces 339 of the cam 317 bear radially outwardly on the bearing surfaces 333 of all the grains 14, in a substantially centered position. relative to each grain, so that the two locking shoes 22, 24 of each grain are thus held in engagement respectively with the locking surfaces 21, 23.

  On the other hand, when a user releases the articulation mechanism 5, for example by actuating the handle 6 in the direction of the arrow 6a (see FIGS. 45 and 46), the cam surfaces 339 of the cam 318 do not act. more on the support edges 333 of the grains and penetrate into the notches 333a, while the cam edges 337 of the control mask are in radial abutment on the bearing surfaces 34 of the grains, so that the second locking pads 24 also remain engaged with the second locking lands 23. Moreover, the cam edges 337 of the control mask abut the corresponding unlocking fingers 36 of the grains, which causes the grains 14 to pivot, so that the first Locking pads 22 of the grains no longer cooperate with the first locking surface 21.

  Other mechanisms of this fourth range are obtained by removing, for example, seeds 14 from the joint illustrated in FIGS. 39 to 46. Thus, for example, a three-grain joint can be obtained by removing the three grains which do not include pawns 52.

  A fifth example of a range of joints according to the invention is illustrated by FIGS. 47 to 52. The joints of this fifth range have an operation similar to that already described in the documents FR 2 806 982. The joints of this range will not be therefore not re-described in detail in this document.

  Each articulation of this range, as previously described, comprises: first and second connecting members, a crimped metal ring or other means of attachment between the connecting members, and a locking device adapted to selectively block or unlock the connecting members in relative rotation about the axis Y. The first connecting member is provided with a first locking surface similar to that of the joints already described.

  In Figure 47 is shown the second connecting member 11, common to all the joints of this fifth range. This second connecting member 11 is constituted for example by a metal flange in the general shape of a disc centered on the Y axis. It is intended to be secured to the frame of the seat. It is usually called fixed.

  This second connecting member 11 conventionally comprises semicutters 54 forming on its outer surface protruding structures for a recovery of effort with the frame of the seat 2. It also comprises a central cavity 55 for accommodating a co-operating spiral spring at its outer end with a notch 58 and at its inner end with a not shown shaft, similar to the shaft 16 already described.

  Protuberances 57 also projecting on the inner surface of the second connecting member 11, but of smaller height than the ramps 56, promote the displacement of any grains placed on it by limiting the contact surfaces between the grain and the inner surface of the second connecting member 11, as well as adhesion phenomena related to a possible presence of grease between these surfaces.

  The second connecting member 11 further comprises six ramps 56 projecting on its inner surface. These ramps 56 are distributed in pairs angularly spaced 120 from each other. Each ramp 56 has one side for guiding and locking a locking grain 414a or a blocking grain 414b and another side for guiding and blocking an overlock grain 414c.

  In Figure 48, there is shown an articulation of the fifth range of joints in which are placed two locking grains 414a. We thus obtain a first articulation model for this fifth range, with two grains 414a.

  In FIG. 49 is shown another articulation of the fifth range of joints, in which two locking grains 414a have been placed, as well as a locking grain 414b. By adding this blocking grain 414b, relative to the articulation described above, it strengthens the blocking capacity of the backrest with respect to the seat in case of impact, thanks to the 415 wedge ends 414b grain that cooperate with the ramps 56 to force this grain 414b into engagement with the toothing of the first connecting member (not shown). This function is described in more detail in the document FR 2 806 981. This gives a second articulation model for this fifth range, with three grains 414a, 414b.

  FIG. 50 shows another articulation of the fifth range, in which an overlocking grain 415c has been added, relative to the articulation of FIG. 49. The operation of such an overlock grain 414c is described in a manner FR 2 806 982. The overlocking grain 414c has a function similar to that of the locking grain 414b. It acts by jamming effect so as to further strengthen the mechanical strength of the joint. A third model of articulation is thus obtained for this fifth range, with four grains 414a, 414, 414c.

  In Figure 51 is shown yet another articulation of the fifth range of joints. This differs from that previously described in that it comprises a second overlocking grain 414c to further enhance the mechanical strength of the joint. A fourth articulation model is thus obtained for this fifth range, with four grains 414a, 414b, 414c.

  Similarly, FIG. 52 represents an articulation of the fifth range of joints, in which yet another overlocking grain 414c has been added to that of FIG. 51. A fifth articulation model is thus obtained for this fifth range. with six grains 414a, 414b, 414c.

  Figures 47 to 52 thus illustrate five models of the fifth range of joints. These different models therefore differ essentially from one another in the number of grains and the shape of the grains. The grain guides, here constituted by the ramps 56, are the same for all the joints of this fifth range.

  In a sixth example of a range of joints (not shown), the seat may comprise a hinge mechanism which differs from that of the first form essentially in that it has no ramps 50 nor pins 52 to maintain the grains in the unlocked position during a tilting of the backrest favoring access to the rear seats. In this case, the hinge mechanism makes it possible to control only a so-called comfort adjustment of the backrest relative to the seat.

Claims (14)

  1. Range of articulation mechanisms, wherein each articulation mechanism (5,105) is intended between two elements (2,4) second (11, 111) angular adjustment members to allow one and comprises: - first (10,110) and rigid link mounted the other and intended to be elements (2,4) to be adjusted to the pivoting relative to each respectively connected to two minus one (10,110) of the first (10,110) and second (11,111) connecting members comprising at least a first locking surface (21,121) extending over at least a portion of a circle centered on an axis of rotation (Y), - at least one grain (14,114,214,414a, 414b, 414c) rigid , housed between the first (10,110) and second (11,111) connecting members, comprising a locking pad (22,122,222) adapted to engage the first locking surface (21,121), and a control device (15,115) adapted to move this grain between a locked position, in which e it cooperates via its locking shoe (22,122,222) with the first locking surface (21,121), and an unlocked position, in which its locking shoe (22,122,222) is no longer in engagement with the first bearing of locking (21,121), characterized in that the first (10,110) and second (11,111) connecting members are respectively identical for all mechanisms and are adapted to accommodate grains (14,114,214,414a, 414b, 414c) in variable number and / or of variable form.   2. Range according to claim 1, in which all the articulation mechanisms comprise guides (33, 34, 35, 36, 37, 38, 39, 40, 56, 120, 125, 126, 133, 139, 233, 235, 333, 333a, 333b, 337,339) identical in number and shape.   3. Range according to one of the preceding claims, comprising at least one articulation mechanism with P grains (14,114,214,414a, 414b, 414c) and at least one articulation mechanism with N grains (14,114,214,414a, 414b, 414c), with P greater than N. 4. Range according to one of the preceding claims, comprising a hinge mechanism (5,105) wherein at least one of the first (10) and second (11,111) connecting member comprises M guides (56,120,125,126), for guiding the movement of N grains (114,414a, 414b, 414c) between their locked position and their unlocked position, with M greater than or equal to N. 5. A range according to one of the preceding claims, comprising a hinge mechanism (5,105) in which the control device comprises M guides (56,120,125,126) for guiding the movement of N grains (114,414a, 414b, 414c) between them. locked position and their unlocked position, with M greater than or equal to N. 6. Range according to one of the preceding claims, whose articulation mechanisms (5,105) comprise first (10,110) and second (11, 111) connecting members each comprising a first (21, 121) and a second (11, 111) respectively ( 23,123) locking range.   7. Range according to claim 6, wherein the first (21,121) and second (23,123) locking surfaces of each articulation mechanism (5, 105) are superimposed in two distinct planes perpendicular to the axis of rotation.   8. Range according to one of claims 6 and 7, wherein each articulation mechanism (5,105) comprises at least one grain (14,114,214) with a first (22,122,222) and a second (24,124,224) locking pads cooperating respectively each with the first (21,121) and second (23,123) locking lands.   9. Range according to one of claims 6 to 8, wherein each mechanism (5,105) comprises a different number of grains (14,114,214,414a, 414b, 414c) similar, angularly distributed about the axis of rotation, the control device (15,115) being adapted to selectively bring the grains (14,114,214,414a, 414b, 414c) into engagement with the first (21,121) and second (23,123) interlocking lands.   10. Range according to one of claims 6 to 9, wherein each articulation mechanism (5,105) comprises grains (14,114,214), the first (22,122,222) and second (24,124,224) locking shoes succeed each other, in different planes. , according to an arc of a circle centered on the axis of rotation (Y).   11. Range according to one of the claims   preceding, comprising at least two mechanisms of joints (5,105) having a distinct number of grains (14,114,214,414a, 414b, 414c) of between 1 and 6.   A method of manufacturing a range of hinge mechanisms (5, 105), wherein each hinge mechanism is intended to allow angular adjustment between two members (2,4), in which method is provided, for each articulation mechanism (5,105). - First (10,110) and second (11,111) rigid connecting members pivotally mounted relative to each other and intended to be respectively connected to the two elements (2,4) to be adjusted, at least one of the first (10,110) and second (11,111) connecting members having at least a first locking surface (21,121) extending over at least a portion of a circle centered on an axis of rotation (Y), - at least one grain ( 14,114,214,414a, 414b, 414c), housed between the first (10,110) and second (11,11) connecting members, comprising a locking shoe (22,122,222) adapted to engage the first locking surface (21,121) - and a control device adapted to move this grain (14, 114, 214, 414a, 414b, 414c) between a locked position, in which it cooperates via its locking shoe (22, 122, 222) with the first locking surface (21, 121 ), and an unlocked position, in which his atin of locking (22,122,222) is no longer in engagement with the first locking surface (21, 121), characterized in that the first (10,110) and second (11,111) connecting members are respectively identical for all the mechanisms ( 5,105) and are adapted to house grains (14,114,214,414a, 414b, 414c) in variable number and / or of variable form.   13. The method of claim 12, wherein one carries out articulation mechanisms whose number of grains (14,114,214,414a, 414b, 414c) is between 1 and 6.   14. Motor vehicle seat comprising a seat and an articulated backrest via a hinge mechanism (5,105) of the range according to one of claims 1 to 11.