Ring for vehicle seat and vehicle seat including ring

Abstract

Ring (48) for a vehicle seat intended to be inserted into a passage of a seat flange (44) comprising: a bearing portion (110), the bearing portion has an annular portion (112) and a bearing rim (115), the annular portion has an internal annular surface (111) and an external annular surface (113), at least one retaining tab (120), each retaining tab (120) has a rod (122) and a retaining portion (124), the retaining portion (124) has a stop surface (125), at least one holding tab (130), each holding tab (130) extends between a first holding end (131) and a second holding end (139), each holding tab (130) has an internal holding surface (132) which projects at the second holding end (139) relative to the first end of maintenance (131). Figure for abstract: Figure 7

Description

Title of the invention: Ring for vehicle seat and vehicle seat comprising the ring Field of disclosure

[0001] The present disclosure relates to a vehicle seat ring and a vehicle seat comprising the ring. State of the art

[0002] The present disclosure relates more specifically to a ring intended to be inserted into a passage of a flange of a backrest to guide the rotation of the backrest, in particular between a position of use and a folded position.

[0003] Such a ring is notably described in document US2021 / 095 735 AL

[0004] The present disclosure aims in particular to facilitate the installation of the ring, improve the robustness of the seat and the quality perceived by the user. Disclosure Statement

[0005] In accordance with these objectives, in accordance with the disclosure, said ring comprises:

[0006] a bearing portion, the bearing portion has an annular portion and a bearing rim, the annular portion has an inner annular surface and an outer annular surface, the inner annular surface is of substantially circular section extending around an axis of rotation, the axis of rotation extends in a transverse direction, the bearing rim has a first bearing surface and a second bearing surface, the first bearing surface extends perpendicular to the transverse direction,

[0007] at least one retaining tab, each retaining tab extends in the transverse direction between a first retaining end and a second retaining end, each retaining tab has a rod and a retaining portion, each retaining tab is connected to the annular portion by the first retaining end, the retaining rod extends from the first retaining end to the retaining portion, the retaining portion is arranged close to the second retaining end, the retaining rod is elastically flexible to allow movement of the retaining portion radially to the axis of rotation between an active position and a retracted position, the retaining portion has a stop surface facing the first bearing surface,the retaining rod biases the retaining portion toward the active position in which the retaining portion is configured to retain the flange between the first bearing surface and the stop surface, ,

[0008] at least one holding tab, each holding tab extends in the transverse direction between a first holding end and a second holding end, each holding tab has an internal holding surface and an external holding surface, each holding tab is connected to the annular portion by the first holding end, the internal holding surface projects at the second holding end relative (to the internal holding surface) to the first holding end, each holding tab is elastically flexible to allow movement of the second holding end of each holding tab radially to the axis of rotation, so as to apply (under pressure) the second holding end against an articulation surface.

[0009] Thus, the ring can be easily secured to the flange and the radial clearances between the articulation surface and the flange are reduced. Consequently, the quality perceived by the user is increased and the noise generated by vibration between the articulation surface and the flange is reduced.

[0010] According to another characteristic in accordance with the disclosure, the ring preferably further comprises slots extending between the at least one retaining tab and the at least one holding tab.

[0011] Thus, the movement of each retaining tab radially to the axis of rotation independently of each holding tab, and vice versa, is improved.

[0012] In various embodiments of the ring according to the disclosure, one and / or the other of the following arrangements may optionally be used:

[0013] the slots extend in the transverse direction;

[0014] each holding tab comprises a main portion and an annular protrusion projecting from the inner holding surface proximate the second holding end of each holding tab;

[0015] the protuberance extends in the transverse direction over a distance of between 1 and 3 millimeters;

[0016] the ring comprises a plurality of retaining tabs and a plurality of holding tabs;

[0017] the ring comprises at least three retaining tabs and three holding tabs;

[0018] each retaining tab and each holding tab is curved in section perpendicular to the transverse direction;

[0019] the plurality of retaining tabs extends over a total angular sector of at least 90 degrees;

[0020] each retaining tab has an outer retaining surface, at the second retaining end the outer retaining surface is beveled;

[0021] the ring further comprises an opening extending in the transverse direction, through the ring.

[0022] The present disclosure further relates to a seat. According to the present disclosure, in addition to the aforementioned ring, the seat comprises:

[0023] - a guide device, the guide device comprises a portion of articulation, the articulation portion has an articulation surface of circular section,

[0024] - a backrest mounted pivoting in rotation around the axis of rotation on the device of guide, the backrest comprises a backrest structure, the backrest structure comprises a flange, the flange comprises a first lateral face, a second lateral face and a passage, the passage extends between the first lateral face and the second lateral face, the passage has a passage surface,

[0025] and the seat further has the following characteristics:

[0026] - the annular portion of the ring extends into the passage, the outer annular surface of the ring is in contact with the passage surface,

[0027] - the first bearing surface of the ring is in contact with the second lateral face from the flask,

[0028] - the stop surface of the ring is in contact with the first lateral face of the flange,

[0029] - the articulation surface is surrounded by the internal annular surface of the portion support, and

[0030] - at the second holding end the internal holding surface of the ring applies pressure against the articulating surface.

[0031] In various embodiments of the ring according to the disclosure, one and / or the other of the following arrangements may optionally be used:

[0032] - the articulation portion comprises a first stop element and a second stop element, the ring further comprises an opening extending through the ring in the transverse direction, the opening is configured to allow the passage of the second stop element through the opening by translation in the transverse direction, the articulation surface is arranged between the first stop element and the second stop element in the transverse direction, the first stop element abuts against the second bearing surface of the ring in the transverse direction;

[0033] - the second abutment element is configured to abut against the second retaining end of the at least one retaining tab and against the second holding end of the at least one holding tab;

[0034] - the articulation surface is surrounded by the internal annular surface of the portion support,

[0035] - the support portion comprises an indexing pin projecting from the first bearing surface in the transverse direction, and the indexing pin cooperates with a hole in the flange;

[0036] - the seat further comprises a first support and a second support intended to be connected to a vehicle chassis, and the guide device further comprises a first support portion and a second support portion, the first support portion cooperates with the first support and the second support portion cooperates with the second support, the backrest forms a second backrest, and the seat further comprises a first backrest comprising a first backrest structure, the first backrest structure is pivotally mounted relative to the first support and the second support around the axis of rotation;

[0037] the first file is rigidly fixed to the guide device. Brief description of the figures

[0038] Other features and advantages of the present disclosure will become apparent from the following detailed description, with reference to the accompanying drawings in which:

[0039] [Fig-1] represents in perspective a vehicle comprising a seat,

[0040] [Fig.2] a partial representation on an enlarged scale following the arrow marked II in [Fig.l],

[0041] [Fig.3] is a representation on a further enlarged scale of the area marked III in [Fig.2],

[0042] [Fig.4] is a partial representation along the arrow marked IV in [Fig.3],

[0043] [Fig.5] is a perspective representation of the seat assembly,

[0044] [Fig.6] is a sectional view along the line marked VI-VI in [Fig.3] illustrating including a seat ring,

[0045] [Fig.7] is a sectional view along the line marked VII-VII in [Fig.6],

[0046] [Fig.8] illustrates the ring alone in perspective. Detailed Description of Disclosure

[0047] [Fig.l] illustrates a vehicle 100, more precisely a motor vehicle. The vehicle 100 comprises a chassis 6 and a bench seat formed from a set of seats 90. The vehicle 100 has a longitudinal direction X, corresponding substantially to the direction of movement of the vehicle, a transverse direction Y, perpendicular to the longitudinal direction X and an elevation direction Z, perpendicular to the longitudinal direction X and to the transverse direction Y. The seat assembly 90 comprises a seat 1 and an auxiliary seat 80.

[0048] As illustrated in particular in Figures 1 to 5, the seat 1 essentially comprises a first support 2, a second support 4, a guide device 10, a first backrest 30 and a second backrest 40, as well as a first seat and a second seat. The first support 2 and the second support 4 are each fixed to a frame 6, preferably by screws or bolts (not shown). The first seat and the second seat are not shown. The first seat is positioned in correspondence with the first backrest 30 and the second seat is arranged in correspondence with the second backrest 40. The first seat and the second seat may be separate and / or foldable, but the first seat and the second seat preferably form a single-piece portion, fixed to the chassis 6 of the vehicle 1.

[0049] The guide device 10 comprises a first support portion 12, a second support portion 14, a first articulation portion 22 and a second articulation portion 24.

[0050] In the illustrated embodiment, the guide device 10 is pivotally mounted about an axis of rotation 50 relative to the chassis 6. The axis of rotation 50 extends in the transverse direction Y. In fact, the first support portion 12 is pivotally mounted about the axis of rotation 50 relative to the first support 2 and the second support portion 14 is pivotally mounted relative to the second support 4 about the axis of rotation 50.

[0051] More precisely, the guide device 10 comprises a guide member 18 of which the first articulation portion 22 forms part. The first articulation portion has a guide bore 11. The first support 2 comprises a support shaft 3 and the support shaft 3 cooperates with the guide bore 11.

[0052] The support 4 has a support bore 5. The second support portion 14 comprises a support surface 13 which is cylindrical. The support surface 13 cooperates with the support bore 5.

[0053] The first backrest 30 comprises a first backrest structure 35. In the illustrated embodiment, the first backrest structure 35 is rigidly attached to the guide device 10.

[0054] The second backrest 40 comprises a second backrest structure 45, a first flange 42 and a second flange 44. The first flange 42 and the second flange 44 are rigidly fixed to the second backrest structure 45. The seat 1 comprises a first ring 46 and a second ring 48. The first ring 46 cooperates with the first flange 42 to form a first bore 4L. Perpendicular to the transverse direction Y, the first bore comprises a first circular portion 41C and a first notch 41E. The first circular portion 41C has a first diameter 41. The second ring 48 cooperates with the second flange 44 to form a second bore 43. Perpendicular to the transverse direction Y, the second bore comprises a second circular portion 43C and a second notch 43E. The second circular portion 43C has a second diameter ¢43. The second diameter is substantially equal to the first diameter.In the embodiment illustrated in Figures 1 to 8, the first ring 46 is identical to the second ring 48 and the first flange 42 is little different from the second flange. 44, substantially symmetrical with the second flange relative to a median plane perpendicular to the transverse direction U.

[0055] The second flange 44 comprises a first lateral face 44a, a second lateral face 44b, a passage 44d and a hole 44e. The first lateral face 44a and the second lateral face 44b extend perpendicular to the transverse direction Y.

[0056] The first articulation portion 22 comprises a first articulation surface 21 which is cylindrical, of circular section and extends around the axis of rotation 50. The first articulation surface 21 cooperates with the first circular portion 41C to guide the first flange 42 in rotation around the axis of rotation 50 relative to the guide device 10. The first articulation portion 22 is arranged between the first support portion 12 and the second support portion 14 in the transverse direction Y.

[0057] As illustrated in particular in Figures 6 to 8, the ring 48 essentially comprises a support portion 110, retaining tabs 120 and holding tabs 130.

[0058] The bearing portion 110 comprises an annular portion 112 and a bearing rim 115. The annular portion has an internal annular surface 111 and an external annular surface 113. The internal annular surface 111 is of substantially circular section extending around the axis of rotation 50. The annular portion 112 of the second ring 48 extends into the passage 44d of the second flange 44. The external annular surface 113 of the second ring 48 is in contact with the passage surface 44d of the second flange 44.

[0059] The bearing rim 115 has a first bearing surface 114 and a second bearing surface 116. The first bearing surface 114 and the second bearing surface 116 extend perpendicular to the transverse direction Y. The first bearing surface 114 of the second ring 48 is in contact with the second lateral face 44b of the second flange 44.

[0060] The bearing portion 110 further comprises an indexing pin 118 projecting from the first bearing surface 114 in the transverse direction Y. The indexing pin 118 cooperates with the hole 44e.

[0061] Each retaining tab extends in the transverse direction Y between a first retaining end 121 and a second retaining end 129. Each retaining tab 120 has a rod 122 and a retaining portion 124. Each retaining tab 120 is connected to the annular portion 112 by the first retaining end 121. The retaining rod 122 extends from the first retaining end 121 to the retaining portion 124. The retaining portion 124 is arranged in proximity to the second retaining end 129. The retaining rod 122 is elastically flexible in order to allow movement of the retaining portion 124 radially to the annular portion 112. the rotation axis 50. between an active position (illustrated in strong lines in [Fig.7]) and a retracted position (illustrated in mixed lines, called ghost lines). The retaining portion 124 has a stop surface 125 facing the first bearing surface 114. The retaining rod 122 urges the retaining portion 124 towards the active position. In the active position, the stop surface 125 is in contact with the first lateral face 44a of the second flange 44, so that the second flange 44 is retained between the first bearing surface 114 and the stop surface 125.

[0062] Each holding tab 130 extends in the transverse direction Y between a first holding end 131 and a second holding end 139. Each holding tab 130 has an inner holding surface 132 and an outer holding surface 134. Each holding tab 130 is connected to the annular portion 112 by the first holding end 131. The inner holding surface 132 projects at the second holding end 139 relative to the first holding end 131. More specifically, each holding tab 130 comprises a main portion 135 and an annular protrusion 136. The annular protrusion 136 projects from the inner holding surface 132 near the second holding end 139 of each holding tab 130. Each holding tab 130 is elastically flexible. Each retaining tab has an outer retaining surface 128.At the second retaining end 129 the outer retaining surface 128 is beveled, in order to facilitate the insertion of the second ring 48 into the passage 44d of the second flange.

[0063] The second articulation portion 24 comprises a second articulation surface 23, a first stop element 26 and a second stop element 28. The second articulation surface 23 is arranged between the first stop element 26 and the second stop element 28 in the transverse direction Y. The second articulation surface 23 is cylindrical, of circular section and extends around the axis of rotation 50. The second articulation surface 23 cooperates with the second circular portion 43C to guide the second flange 44 in rotation around the axis of rotation 50 relative to the guide device 10. Thus, the second backrest 40 is guided in rotation around the axis of rotation 50 relative to the guide device 10. The second articulation portion 24 is arranged between the first support portion 12 and the second support portion 14 in the transverse direction Y.The second articulation surface 23 is surrounded by the internal annular surface 111 of the bearing portion 110. The internal annular surface 111 of the bearing portion 110 forms the second circular portion 43C. And, at the second holding end 139, the internal holding surface 132 of the annular protuberance 136 is applied under pressure against the second articulation surface 23. The annular protuberance 136 is in contact with the second articulation surface 23 over a distance d along . the transverse direction Y. The distance d is preferably between 1 and 3 millimeters, advantageously close to 1.7 millimeters.

[0064] As illustrated in [Fig. 6], there is a clearance between the inner retaining surface 126 of the retaining tabs 120 and the second articulation surface 2. The clearance between the inner retaining surface 126 of the retaining tabs 120 and the second articulation surface 2 is preferably greater than or equal to 0.3 millimeters, advantageously close to 0.5 millimeters. Furthermore, there is a clearance between the outer retaining surface 134 of the retaining tabs 130 and the second articulation surface 2. The clearance between the outer retaining surface 134 of the retaining tabs 10 and the second articulation surface 2 is preferably greater than or equal to 0.3 millimeters, advantageously close to 0.5 millimeters.

[0065] The second ring comprises four retaining tabs 120 and three holding tabs 130. An opening 150 extends through the second ring 48 in the transverse direction Y. The opening 150 extends between two retaining tabs 120, circumferentially to the axis of rotation 50. The opening 150 defines with the second flange 44 the second notch 43E. Each holding tab 130 is arranged between two retaining tabs 120, perpendicular to the transverse direction Y, circumferentially to the axis of rotation 50.

[0066] The second ring 48 further comprises slots 140 extending in the transverse direction Y between the retaining tabs 120 and the holding tabs 130, up to the support portion 110.

[0067] The first stop element 26 and the second stop element 28 are rigid. As illustrated in particular in [Fig. 4], the first stud 26 and the second stud 28 are angularly in correspondence around the axis of rotation 50. The first stop element 26 forms a stud projecting from the second articulation surface 23 by a first height H. The second stop element 28 also forms a stud but projecting from the second articulation surface 23 by a second height h. The first height H is greater than the second height h, preferably between 50% and 200% more, in other words between 1.5 and 3 times the first height h.

[0068] As illustrated in particular in [Fig.5], the first notch 41E is angularly in correspondence with the second notch 43E.

[0069] The guide device 10 further comprises a third articulation surface 25 and a third stop element 29. The annex seat 80 has an annex flange 82. The annex flange 82 has an annex bore 81. The third articulation surface 25 cooperates with the annex bore 81 to guide the annex seat 80 in rotation around the axis of rotation 50. The third stop element 29 is formed by a lug projecting from the third articulation surface 25. The bore Annex 81 has a notch to allow the passage of the third stop element 29 through the bore Annex 81 by translation in the transverse direction Y.

[0070] The seat 1 further comprises a first locking device and a second locking device. The first locking device has an active state in which it allows the first backrest 30 to be locked relative to the frame 6 in a comfort position. When the first backrest 30 is locked in the comfort position by the first locking device, a user can lean back on the first backrest 30. When the first locking device is in an inactive state, the first backrest 30 can be pivoted (with the guide device 10, in the illustrated embodiment) around the rotation axis 50 and brought into a folded position in which the first backrest 30 rests against the seat.Of course, from the folded position, the first backrest 30 can be returned to the comfort position by rotation about the rotation axis 50 and held in the comfort position by the first locking device. The second locking device has an active state in which it allows the second backrest 40 to be locked relative to the first backrest 30 and an inactive state in which the second backrest 40 is released in rotation about the rotation axis 50 relative to the first backrest 30. When the second locking device is in the active state, the second backrest 40 is secured to the first backrest 30. The second backrest 40 is therefore in the comfort position in which a user can lean against the second backrest 40 when the first backrest 30 is in the comfort position and the second backrest 40 is in the folded position, resting against the seat, when the first backrest 30 is in the folded position.When the first backrest 30 is in the comfort position and the second locking device is in the inactive state, the second backrest 40 can be pivoted about the rotation axis 50 to be brought into the folded position. The second backrest 40 can then be returned to the comfort position by rotation about the rotation axis 50 and relocked to the first backrest 30 or, alternatively, the first backrest 30 can be brought into the folded position and relocked to the second backrest 40.

[0071] As illustrated in [Fig. 5], to assemble the second backrest 40 on the guide device 10, to which the first backrest 30 is previously fixed, the second backrest 40 is angularly placed in an insertion position offset between 120 degrees and 240 degrees relative to the first backrest 30. In this insertion position, the first stop element 26 and the second stop element 28 are in angular correspondence around the axis of rotation 50 with the first notch 41E and the second notch 43E. The insertion position is such that it cannot be obtained when the seat 1 is fixed to the chassis 6 of the vehicle, because the second backrest 40 would collide with the chassis 6.

[0072] The second backrest 40 is then translated along the transverse direction Y in a first direction 52. The third articulation surface 25 and the third stop element 29 pass through the first bore 4L. Then, the second articulation surface 23 passes through the first bore 41 and the second stop element 28 and the first stop element 26 pass successively through the first notch 41E. Then, while maintaining the insertion position, the translation of the second backrest 40 relative to the guide device 10 along the transverse direction Y, in the first direction 52 is continued. The third articulation surface 25 and the third stop element 29 pass through the second bore 43. Then, the second stop element 28 passes through the second notch 43E, then the first stop element 26 abuts against the second circular portion 43C, the second stop element 28 protruding from the second notch 43E..

[0073] Then, the third articulation surface 25 and the third stop element 29 pass successively through the support bore 5 and the annex bore 81.

[0074] The second backrest 40 is then pivoted about the rotation axis 50 relative to the guide device 10 to bring it substantially into the extension of the first backrest in the transverse direction Y. The first stop element 26 has a chamfer 27 which slightly moves the second backrest 40 in relation to the guide device 10, in order to position and tightly hold the second bore 43 between the first stop element 26 and the second stop element 28 in the transverse direction Y. The first stop element 26 prevents the second flange 44 from moving relative to the guide device 10 in the transverse direction Y in the first direction 52 by coming to bear against the second bearing surface 116 of the second ring 48.The second stop element 28 prevents the second flange 44 from moving relative to the guide device 10 in the transverse direction Y in a second direction 54, opposite to the first direction 52, by coming into abutment against the second retaining end 129 of one of the retaining tabs 120 or against the second holding end 139 of one of the holding tabs 130.

[0075] The third stop element 29 retains the guide device 10 relative to the annex seat 80 in the first direction 52 along the transverse direction Y. The second stop element 28 prevents the guide device 10 from moving relative to the second flange 44 (therefore the annex seat 80) along the transverse direction Y in the first direction 52. Conversely, the second stop element 28 prevents the second flange 44 (therefore the second backrest 40) from moving relative to the guide device 10 in the transverse direction Y in the second direction 54.

[0076] It will be noted that in the illustrated embodiment the first flange 42 comprises a first sleeve 46, in order to increase the width of the first circular portion 41C, in the transverse direction Y, without increasing the width of the rest of the first flange 42. The surface of cooperation between the first articulation surface 21 and the first bore 41 is thus increased without significantly increasing the weight of the first flange 42. Similarly, the second flange 44 comprises a second sleeve 48, in order to increase the width of the second circular portion 43C, in the transverse direction Y, without increasing the width of the rest of the second flange 44. The surface of cooperation between the second articulation surface 23 and the second bore 43 is thus increased without significantly increasing the weight of the second flange 44.

[0077] In the illustrated embodiment, the guide device 10 comprises a guide shaft 20 and the guide member 18. The guide shaft 20 is distant from the guide member 18 in the longitudinal direction Y. The guide shaft 20 is rigidly fixed to the first backrest structure 35 and the guide member 18 is rigidly fixed to the first backrest structure 35, such that the guide member 18 is rigidly fixed to the guide shaft 20 via the first backrest structure 35. The guide member 18 comprises the first support portion 12. The guide shaft 20 comprises the second support portion 14, the first articulation portion 22 and the second articulation portion 24.

[0078] Furthermore, the guide device 10 comprises a main portion 15 and a retaining portion 16. The main portion 15 is metallic. The main portion 15 is fixed directly to the first backrest structure 35. The main portion 15 comprises the first support portion 12 and the first articulation portion 22. The retaining portion 16 is made of plastic material overmolded onto the main portion 15. The retaining portion 16 comprises the second support portion 14 and the second articulation portion 24. In the illustrated embodiment, the retaining portion 16 is entirely part of the guide shaft 20.

[0079] Of course, the disclosure is in no way limited to the embodiment(s) described for illustrative, non-limiting purposes. Thus, the ring could be devoid of the opening 150, by replacing the second stop element with an element fulfilling the same function, without requiring it to pass through the part.

Claims

1. Claims Ring (46, 48) for a vehicle seat intended to be inserted into a passage of a seat flange (42, 44), said ring (46, 48) comprising: a bearing portion (110), the bearing portion has an annular portion (112) and a bearing rim (115), the annular portion has an inner annular surface (111) and an outer annular surface (113), the inner annular surface (111) is of substantially circular section extending around an axis of rotation (50), the axis of rotation (50) extends in a transverse direction (Y), the bearing rim (115) has a first bearing surface (114) and a second bearing surface (116), the first bearing surface (114) extends perpendicular to the transverse direction (Y), at least one retaining tab (120), each retaining tab extends in the transverse direction (Y) between a first retaining end (121) and a second retaining end (129), each retaining tab (120) has a rod (122) and a portion of restraint (124),each retaining tab (120) is connected to the annular portion (112) by the first retaining end (121), the retaining rod (122) extends from the first retaining end (121) to the retaining portion (124), the retaining portion (124) is arranged in proximity to the second retaining end (129), the retaining rod (122) is elastically flexible in order to allow movement of the retaining portion (124) radially to the axis of rotation (50) between an active position and a retracted position, the retaining portion (124) has a stop surface (125) facing the first bearing surface (114), the retaining rod (122) urges the retaining portion (124) towards the active position in which the retaining portion (124) is configured to retain the flange (42, 44) between the first bearing surface (114) and the stop surface (125), at least one holding tab (130), each holding tab (130) extends in the transverse direction (Y) between a first holding end (131) and a second holding end (139), each holding tab (130) has an internal holding surface (132) and an external holding surface (134), each holding tab (130) is connected to the annular portion (112) by the first holding end (131), the internal holding surface (132) projects at the second holding end (139) relative to the first holding end (131), each holding tab (130) is elastically flexible to allow movement of the second holding end (139) of each holding tab (130) radially to the axis of rotation (50), so as to apply (under pressure) the second holding end (139) against an articulation surface (21, 23).

2. Ring according to the preceding claim in which the ring (46, 48) further comprises slots (140) extending between the at least one retaining tab (120) and the at least one holding tab (130).

3. A ring according to any preceding claim wherein each retaining tab (130) comprises a main portion (135) and an annular protrusion (136) projecting from the inner retaining surface (132) proximate the second retaining end (139) of each retaining tab (140).

4. A ring according to any preceding claim wherein the ring comprises a plurality of retaining tabs (120) and a plurality of holding tabs (130).

5. A ring according to any preceding claim wherein each retaining tab has an outer retaining surface (128), at the second retaining end (129) the outer retaining surface (128) is beveled.

6. Vehicle seat comprising a ring according to any of the preceding claims, the seat further comprising: - a guide device (10), the guide device (10) comprises an articulation portion (22, 24), the articulation portion (22, 24) has an articulation surface (21, 23) of circular section, - a backrest (40) pivotally mounted in rotation about the axis of rotation (50) on the guide device (10), the backrest (40) comprises a backrest structure (45), the backrest structure (45) comprises a flange (42, 44), the flange (42, 44) comprises a first lateral face (44a), a second lateral face (44b) and a passage (44d), the passage (44d) extends between the first lateral face (44a) and the second lateral face (44b), the passage (44d) has a passage surface (44c), in which: - the annular portion (112) of the ring (46, 48) extends into the passage (44d), the external annular surface (113) of the ring (46, 48) is in contact with the passage surface (44d), - the first bearing surface (114) of the ring (46, 48) is in contact with the second lateral face (44b) of the flange (44), - the stop surface (125) of the ring (46, 48) is in contact with the first lateral face (44a) of the flange (44), - the articulation surface (21, 23) is surrounded by the internal annular surface (111) of the bearing portion (110), and - at the second holding end (139) the internal holding surface (132) of the ring (46, 48) is applied under pressure against the articulation surface (21, 23).

7. Seat according to the preceding claim wherein: - the articulation portion (24) comprises a first stop element (26) and a second stop element (28), - the ring (48) further comprises an opening (150) extending through the ring (48) in the transverse direction (Y), the opening (150) is configured to allow the passage of the second stop element (28) through the opening (150) by translation in the transverse direction (Y), - the articulation surface (23) is arranged between the first stop element (26) and the second stop element (28) in the transverse direction (Y), the first stop element (26) is in abutment against the second bearing surface (116) of the ring (48).

8. Seat according to the preceding claim in which the second stop element (28) is configured to come into abutment against the second retaining end (129) of the at least one retaining tab (120) and against the second holding end (139) of the at least one holding tab (130).

9. Seat according to any one of claims 6 to 8 in which: - the support portion (110) comprises an indexing pin (118) projecting from the first support surface (114) in the transverse direction (Y), and - the indexing pin (114) (118) cooperates with a hole (44e) in the flange (44).

10. A seat according to any one of claims 6 to 9 wherein: - the seat (1) further comprises a first support (2) and a second support (4) intended to be connected to a vehicle chassis (6), and - the guide device (10) further comprises a first support portion (12) and a second support portion (14), the first support portion (12) cooperates with the first support (2) and the second support portion (14) cooperates with the second support (4), - the file (40) forms a second file, and - the seat further comprises a first backrest (30) comprising a first backrest structure (35), the first backrest structure is pivotally mounted relative to the first support (2) and to the second support (4) around the axis of rotation (50).

Images