FR2619061A1 - JOINT FERRULE FOR SEAT - Google Patents

Abstract

The articulation fitting for a seat, in particular for an automobile seat with an adjustable backrest, comprises a fixed articulation part associated with the seat portion of the seat and a pivoting articulation part associated with the back of the latter, said articulation parts being interconnected by a pivot pin. A spring assembly 24, disposed on the segment 14 of the pivot pin 13 which protrudes from the other articulation part 12, biases the two articulation parts 11, 12 against one another. a seat with continuously adjustable position without radical play.

Description

JOINT FERRULE FOR SEAT

  The present invention relates to an articulated fitting

  seat installation, in particular for an automobile seat with an adjustable backrest, comprising a fixed hinge portion

  associated with the seating part of the seat and a part of

  pivoting portion associated with the backrest thereof, said hinge portions being interconnected by a pivot axis, while an adjustment and locking mechanism which determines the relative position of the two hinge parts is constituted by a gear mechanism comprising at least one ring gear with internal teeth and

  minus one spur gear meshing with said internal toothing

  re, said gear mechanism being capable of being -

  actuated by a central (median) driving element of the pivot axis which is, in turn, capable of being rotated by a control member, said fitting further comprising a friction brake mechanism called to block said hinge parts in their

desired relative position.

  Knuckle fittings are known for adjusting the backrest of a seat, the hinge parts of which are mounted on a pivot axis in a manner that is displaceable with respect to the other, the pivot axis comprising a central drive member formed by an eccentric segment which supports a sun gear rotating inside a ring gear; the latter constitutes an organ of one of the two articulation parts, while the

  planetary wheel constitutes an organ of the other

  lation. The respective numbers of teeth of the planetary wheel

  and the inner gear ring differ by at least one unit (one tooth) and the eccentricity of the eccentric relative to the center of the pivot axis corresponds to at least half the height (or depth ) teeth. We

  called this kind of gear mechanism for horseshoe

  "Oscillating hardware" and are considered as adjustment and locking mechanisms with automatic braking effect (or "self-braking"), taking into account the friction conditions between the teeth and in particular the friction

  between the eccentric segment and the toothed wheel it carries.

  Generally, the pivot axis presents, in front of and behind the eccentric segment, two centric segments, one directly carries one of the hinge parts which cooperates with

  the other segment centered through a flange.

  Knuckle fittings are also known in which each of the hinge parts comprises a ring gear with internal teeth and in which these teeth

  interior have different numbers of teeth.

  Each of the internally toothed crowns cooperates with a spur gear whose number of teeth is less than that of the inner gear ring associated therewith. In these devices, the spur gears are also mounted on

  an eccentric segment acting as a training organ

  whose eccentricity ensures the maintenance of the engrene-

  between the spur gears and the spur gears

interior.

  Another hinge fitting also has, on the two hinge parts, an internal toothing; the respective numbers of teeth of these are different, but their pitch circle diameters are equal, as are their modules. The two inner toothing meshes each with at least one sun wheel, preferably with two planetary wheels, interested hinge parts, these planetary wheels meshing in turn with a sun wheel

  acting as a driving member.

  Due to the manufacturing tolerances, it is found, on the one hand, that misalignments occur between

  centered bearings and, on the other hand, excessive radial clearance

  sif can occur in bearings and teeth. Because of the radial clearance and a poor profile (due to the manufacturing processes) of the teeth, there is a periodic wedging of the pivot axis in its bearings, which causes significant variations in the adjustment torque or adjusting. On the other hand, the self-braking effect of such hinge pins is reduced when there is a bearing between the eccentric segment and the rotating member on it to reduce the resistance (friction) to adjustment maneuvers, however, as vibration and shaking occur when the vehicle is moving, the hinge fitting is constantly exposed - at least because of the weight of the backrest - to solicitations

  which, in the long run, can lead to displacement or

  minimal seat backrest, which then forces the user to

  to readjust the hinge fitting.

  According to DE-B-2 446 181, an adjustment device is provided which overcomes this drawback in that it comprises, between a control wheel and the pivot axis, a safety device consisting of a type of coupling said spring coiled. The arrangement and operation of such a coupling are described in particular in DE-A-1 580 017. A coupling of this type has the disadvantage of a relatively large size due to the fact that it comprises a plurality of turns of springs juxtaposed and, moreover, it is subject to a game inherent in the operation, between the coupling member acting on the ends of the driving member, on the one hand, and the locking or locking member which also acts on the ends

  of the coaching organ, on the other hand.

  The object of the present invention is to improve an articulation fitting of the above-mentioned kind in such a way that it

  ensures that the appropriate file is kept in the correct position.

  the radial clearance is substantially eliminated and that the actuating torque is appreciably

  constant during the adjustment movement of the backrest.

  This object is achieved, according to the invention, in that the axis

  of pivoting comprises a partial crown

  externally, one of the hinge parts, while a spring assembly is disposed on the

  of the pivot axis which protrudes from the other part of the articu-

  tion and urges said two articulation parts against each other. Due to this positioning mode of the centric segment of the pivot axis in one of the articulating parts and thanks to the biasing of said pivot axis by the spring assembly, this axis is forced, even when it is subjected to loads, to remain constantly in a median position involving no jamming, that is to say in a centered position where it is parallel to the theoretical bearing axis. Thanks to the resistance capacity of the pivot against the force of elasticity, it is possible to eliminate

almost completely radial play.

  In a simple embodiment of the invention, the pivot axis comprises an eccentric segment supporting the articulation part, with the support ring, which segment is followed by a centered cylindrical segment engaged in the defined bearing.

  by a flange integral with the hinge part suppor-

  by the centered segment, the bearing recess of the flange surrounding the other cylindrical centered with a certain clearance.

  It is understood, however, that the cylindrical segment

  centered and the eccentric segment are raised in order to take into account the possible play, compared to the

  measurable value of the distance between the top of the

  and the opposite vertex of the centric segment (centric segment radius plus eccentricity, plus eccentric radius). The

  elastic loading of the pivot axis due to the

  seems to spring, serves in addition, to press the parts of articles

  against the other in the area of the outer annular surfaces, above the toothing, which provides a complementary braking torque which, on the one hand, ensures the maintenance in the desired adjustment position and, on the other hand, avoids jerky movements when

the lowering of the file.

  In one embodiment of the hinge fitting which makes it possible to reduce its bulk, the spring assembly is constituted by at least two elastic washers (Belleville washers), one of said washers being fixed on the axis. pivoting by a retaining ring, while the other elastic washer urges the hinge portion carried by the cylindrical segment centered. In order to facilitate the adjustment movements, it may be advantageous to provide a variant in which a thrust bearing bearing is arranged between the opposite sides of the hinge parts and the eccentric support ring, on the one hand, and the spring assembly on the other. For the same reason, the hinge parts are preferably

  articulated on the pivot axis by means of bearings.

  According to an advantageous arrangement for reducing the width of the fitting, on the one hand, and the number of bearings, the hinge part carried by the centered cylindrical segment of the pivot axis is mounted on this segment via a bearing absorbing radial and axial forces. Advantageously, the combined axial and radial bearing comprises a bearing receiving the hinge portion mounted centrally, and provided with a ball bearing track provided on the hinge portion, a bearing ring axially displaceable on the axis. as a plurality of interposed bearing balls, while the spring assembly held on the one hand on the cylindrical segment urges, on the other hand, directly the ring of

rolling.

  In order to allow, during the adjustment movement of the hinge fitting, the pivot axis to execute without swinging a swaying oscillating movement, due to manufacturing tolerances, the bearing ring delimiting on one side the Eccentric segment of said pivot axis preferably comprises a convex convex bearing surface corresponding to a concave curved bearing surface of an axial thrust disc of the axial thrust bearing which solicits the

  hinge mounted on the eccentric segment.

  Other goals, benefits and features will appear

  upon reading the description of the embodiments of

  the invention, a non-limitative description and in

look at the attached drawing, or:

  FIG. 1 shows a hinge fitting comprising

  both the locking mechanism according to the invention

  side elevation; - Figure 2 is a vertical section taken along the line II-II of Figure 1; - Figure 3 shows a modified embodiment of the hinge fitting according to Figure 2, in the form of a section similar to that of Figure 2; in this mode of

  realization, the two parts of articula-

  tion are articulated with bearings and the support ring defining the eccentric segment comprises a curved bearing surface; FIG. 4 shows the use of the locking device according to the invention in a hinge fitting, the two hinge parts of which comprise an internally toothed ring meshing with a spur gear spun on an eccentric; FIG. 5 shows a hinge fitting which comprises a locking device, the two hinge parts of this fitting.

  with integral toothed crowns

  upper meshing with planetary wheels may be driven by a member constituted by a sun wheel

formed on the pivot axis.

  The hinge fitting 10 comprises a part of articles

  fixture 11 associated with the plate portion of the

  seat, as well as a pivoting joint part 12

  The two hinge parts are connected to each other by means of a pivot pin 13 so as to be pivotable relative to one another. The pivot axis 13 of a hinge fitting according to the embodiments shown in Figures 1 to 4 has segments of centered cylindrical portions 14, 15 between which is disposed an eccentric cylindrical segment or portion 16

  which acts as a driving member. The articulating part

  pivoting portion 12 associated with the backrest is pivotally mounted on the cylindrical segment centered 14; in the mode of

  tion according to FIG. 2, the support disk 18 formed by stamping

  wise in the hinge portion 12 to define the ring gear 17 is disposed directly on the centered cylindrical segment 14 so as to constitute a sliding bearing (pad). In the embodiments according to FIGS. 1 to 3, the internal toothing of the crown 17

  the hinge portion 12 meshes with the external toothing

  a right gear 19 of the hinge portion 11 which is mounted on the eccentric segment 16, this spur gear 19

  being obtained by stamping or the like of the articula-

  the articulation part 11.

  The spur gear 19 is rotatably mounted on the eccentric segment 16 via a bearing or bearing, such as cylindrical bearing, needle bearing or the like. The meshing zone between the external teeth of the spur gear 19 and the internal toothing of the crown

  tooth 17 is determined by the eccentricity of the

  The number of teeth of the external toothing of the spur gear 19 is at least one less than that of the internal toothing of the ring gear 17, while the diameter of the ring of right spur head is less than at least one tooth height (or tooth depth) to the root diameter of the toothing of the ring gear 17 with internal teeth. The hinge portion 12 associated with the back of the seat is secured to a bearing flange 21 which covers the actual hinge area of the hinge portion 11 and which comprises a pad 22 mounted forcibly and surrounding with clearance. segment

  cylindrical 15 of the pivot axis.

  A bearing ring 23 concentric with the eccentric segment

  that 16 is disposed between it and the cylindrical segment

  that 15; this ring may be formed, for example, by a flange secured to the pivot axis 13. A spring assembly 24 disposed on the cylindrical segment centered 14 against

  the outer face of the spur gear 19 of the articulating part

  latioh 11. The spring assembly 24 is constituted, in the embodiments shown in the drawing, by two spring washers (Belleville washers) 25 and 26. One of the spring washers 25 is supported on the pivot axis, by means of a retaining ring 27, while the other spring washer 26 biases the support disc 18 of the hinge portion 12. In the embodiment shown in FIG. 3, the elastic washer 25 rests directly on the retaining ring 27, while in the

  embodiment according to FIG. 2, the elastic washer

  25 is supported on a thrust ring 28 immobilized axially by the retaining ring 27. Furthermore, in this embodiment, the spring washer 26 is supported by a thrust disk 29 which has a track for a plurality of balls forming a thrust bearing, the other track for these balls being provided on the support disc 18 of the hinge portion 12. In addition, both in the embodiment shown in Figure 2 that in that shown in Figure 3, a thrust or stop bearing 31 also constituted by a bearing is disposed between the bearing ring 23 and the pinion 19 of the hinge portion 11 and the balls engage, on the one hand, in a track 19 and, secondly, in the track of a thrust disk 32. Unlike the embodiment according to the

  2 in which the support disc 18 of the article portion

  FIG. 12 is slidably mounted on the centered cylindrical segment 14, in the embodiment shown in FIG. 3, a bearing 33 connects the hinge portion 12 to the centered cylindrical segment 14 via its support disk. This bearing which absorbs the axial forces as well as the radial forces is constituted, for example, by a track 34 formed on the support disk 18, a bearing ring 35 axially displaceable on the cylindrical segment 14 of the pivot axis and a plurality of balls 36 placed

between the ring 35 and the track 34.

  In the embodiment according to FIG. 2, the ring

  23 on the side facing the pressure disc

  32, a plane bearing surface parallel, while in

  the embodiment according to FIG. 3, the surface of

  spring 37 of the support ring 23 'is convex and curved and cooperates with the bearing surface 38 also convex, but concave, a thrust disc 32' of the bearing 31. This guarantees greater freedom, for the pivot axis, to be able to compensate the oscillation movements of its longitudinal geometrical axis, movements inevitably due to manufacturing tolerances, which exert their effects during

adjustment operations.

  When the pivot axis 13 is rotated, for example by means of a control member disposed on the shaft 39 shown as a section, the meshing zone between the spur gear and the gear ring interior moves angularly in correspondence to the rotary movement of the eccentric segment 16 which rotates, of course, with the pivot axis 13. During an entire revolution of the pivot axis, the hinge portion 12 is then shifted by a division of teeth relative to the hinge portion 11, in a manner known per se. During this rotational movement, and thanks to the spring assembly 24, the pivot axis can be adapted to the actual conditions of the bearings and toothing, with regard to their manufacturing and assembly tolerances. The pivot axis 13 can also execute an oscillating or pendulum movement around the zones of

  bearing defined by the support disc 18 and the cylindrical segment

  centric gear 14, because due to the clearance between the bearing 22 and the outer surface of the centered cylindrical segment 15, this pivot axis can be placed in a

  position in which its median geometric axis is inclined.

  In any case, the spring assembly constantly exerts an axial force on the pivot axis, so that it constantly tends to take a centered position without risk of jamming. At the same time, this axial force generates a braking torque due to the frictional forces between the annular surfaces 40 and 41 of the hinge parts 11 and 12. In combination with the rollers 2G and 33, any jerky movement during movements of the articulation part 12 and the file associated with it is

effectively avoided too.

  In the embodiment shown in FIG. 4, the locking device of the two articulation parts 11 and 12 corresponds to those of the embodiments represented on FIG.

  Figs 1 and 2, as to its structure and operation.

  The present embodiment differs from the two preceding

  teeth essentially by the construction of the hinge fitting 10 'itself. In the embodiment according to FIG. 4, in fact, the eccentric 16 of the pivot axis 13, which constitutes the drive member, carries a spur gear 42 provided, on its periphery, with two different external teeth. 43 and 44. The external toothing 43 of the spur gear 42 meshes with an internal toothing 45 of the hinge portion 12, while the external toothing 44 of said spur gear 42 meshes with an internal toothing 45.

  of the hinge portion 12, while the external toothing

  The inner gear 45 of the hinge portion 12 has at least one more tooth than the external toothing 43 of the spur gear 42. likewise with respect to the teeth 46 and 44. Moreover, the internal toothing 45 has a number of teeth different from at least one unit from that of the internal toothing 46, which consequently applies

  also to the external teeth 43 and 44 of the spur gear 42.

  The eccentric 16 holds the spur gear 42 in the meshing position of its external teeth 43 and 44 with the internal teeth 45 and 46 of the hinge parts 11 and 12, respectively, so that, during a rotation of the pivot axis, the hinge portion 12 pivots relative to

at the hinge part 11.

  The pivot axis 13 of the hinge fitting 10 "according to the embodiment shown in FIG. 5 comprises a centered bearing segment 47 on which the hinge portion 11 is pivotally mounted, however, that the segment forming bearing 47 is associated with a drive member constituted by a sun gear 48. This sun gear cooperates with planet gears 49, in the embodiment according to FIG 5, four satellite wheels are evenly distributed inside the planet gear. an enclosure formed by the hinge parts 11 and 12, the bearings of these wheels being maintained in their relative position by a cage 50 which partially surrounds said wheels 49. These mesh with the internal teeth 51 and 52 of the parts 11 and 12, respectively, these internal teeth 51 and 52 having identical primary circles, but different numbers of teeth, so that it can be produce a relative displacement of the parts

  articulation 11 and 12 when the sun gear 48 rotates.

  The planet wheels 49 are mounted so as to automatically assume a position centered between the internal teeth 51 and 52 and the toothing of the sun wheel 48. In this embodiment according to the figure, the pivot axis 13 can also be adapted the actual conditions, with regard to the tolerances, thanks to the spring assembly 24, because here also, the bearing segment 53 of the axis of

  pivoting is covered with play by the cover disc

  54 of the hinge portion 12, while the support ring 23 immobilized on the segment 53 presses the hinge portion 12 by its annular surface 40 against the annular surface 41 of the hinge portion, so as to

generate a braking torque.

  Of course, the present invention is not limited to the embodiments described and shown but it is capable of numerous variants accessible to the man of

  art without departing from the spirit of the invention.

Claims (8)

  1. A hinge fitting for a seat, particularly for an automobile seat with an adjustable backrest, comprising a fixed hinge part associated with the seat part of the seat and a pivoting hinge part associated with the backrest of the seat. here, said hinge parts being interconnected by a pivot axis, while an adjustment and locking mechanism which makes it possible to determine the relative position of the two hinge parts is constituted by a gear mechanism having at least one ring gear and at least one spur gear meshing with said internal toothing, said gear mechanism being operable by a central (mid) drive element of the pivot axis which is, in turn, capable of being rotated by a control member, said fitting further comprising a friction brake mechanism.Called to block said parts of ar in the desired relative position, characterized in that the pivot axis (13) comprises a bearing ring (23) partially covering, on the outside, one of the articulation parts (11), while a spring assembly (24), disposed on the segment (14) of the pivot axis (13) projecting from the other articulation part (12), urges the one against the other, said two articulation parts (11, 12).   2.- hinge fitting according to claim 1, characterized in that the pivot axis (13) comprises as   drive member, an eccentric segment (16) supporting   both the hinge portion (11) with the support ring (23, 23 ') which is followed by a centered cylindrical segment (15) engaged in the bearing (22) defined by a flange (21) secured to the hinge portion (12) supported by the centered segment (14), the bearing recess of the flange (21) surrounding the other cylindrical segment centered (15) with some play.   3.- hinge fitting according to claim 1 or 2, characterized in that the spring assembly (24) is constituted by at least two elastic washers (25, 26), one of which is fixed on the axis pivoting (13) by a retaining ring (27), while the other spring washer (26) urges the hinge portion (12) carried by the segment centered cylindrical (14).   4.- Hinge fitting according to any one of   Claims 1 to 3, characterized in that a bearing of   bearing stop (30, 31) is arranged between the opposite sides of the hinge parts (11, 12) and the support ring (23, 23 ') of the eccentric (16), on the one hand , and   the spring assembly (26), on the other hand.   5.- Hinge fitting according to any one of   Claims 1 to 4, characterized in that the parts   articulation members (11, 12) are articulated on the pivot axis   (13) with bearings (20, 33).   6.- hinge fitting according to claim 5, characterized in that the hinge portion (12) worn   by the centered cylindrical segment (14) of the pivot axis   (13) is mounted on this segment (14) via   a bearing (33) absorbing the radial and axial forces.   7.- hinge fitting according to claim 6, characterized in that the bearing (33) receiving the hinge portion (12) mounted centrally, comprises a   ball bearing track (34) provided on the article portion   (12), an axially displaceable bearing ring (35)   on the pivot axis (13) as well as a plurality of interposed bearing balls (36) while the assembly   spring (24) maintained on the one hand on the cylindrical segment   that (14) solicit, on the other hand, directly the ring of bearing (35).   8.- Hinge fitting according to any one of   Claims 1 to 7, characterized in that the sealing ring   pin (23 ') delimiting on one side the eccentric segment (16) of said pivot axis (13) has a convex convex bearing surface (37) corresponding to a concave curved bearing surface (38) of a disc of thrust (32 ') of the thrust bearing (31) which urges the hinge portion (11) mounted on the eccentric segment (16).