Mechanism for driving a part of a seat to move and seat comprising such a mechanism

Abstract

The invention relates to a drive mechanism suitable for driving a part of a vehicle seat in movement, the drive mechanism comprising: - a flange provided with a through opening having a first transverse axis, - a centering element (48) comprising a through opening (56), the centering element being fixed to the flange, the through opening being centered on the first transverse axis; - a drive member (50) passing through the through opening of the flange and the through opening (56) of the centering element, the drive member (50) being suitable for pivoting about the first transverse axis, the drive member comprising a first toothing stage (76) cooperating with the centering element, and a second toothing stage (78) having a different shape from the first toothing stage, the second toothing stage being coaxial and attached to the first level of teeth. Figure to be published with the abstract: Figure 7

Description

Title of the invention: Mechanism for driving the movement of a part of a seat and seat comprising such a mechanism Technical field of the invention

[0001] The invention relates to a mechanism for driving a part of a seat, and in particular, to a mechanism for adjusting the height of the seat of a seat. The invention also relates to a seat of a motor vehicle. State of the prior art

[0002] In the field of motor vehicles, the shape of the parts of the chassis of a seat can sometimes be imposed by the vehicle manufacturer so that certain mechanical parts which are in contact with mechanical parts of the chassis must be modified to allow the performance of certain functions.

[0003] The seat drive mechanism may sometimes be produced by a manufacturer other than the manufacturer of the seat frame. The seat height adjustment mechanism may, for example, comprise a drive member capable of engaging with a toothed sector of a connecting rod or with a rack. However, when a manufacturer imposes a particular shape of the teeth of the toothed sector or a particular shape of the teeth of the rack, the drive member and the centering element of the drive mechanism must be modified to allow the teeth of the drive member to engage with the toothed sector or the rack. In addition, the teeth of the bearing of the centering element must be modified to allow it to engage with the new drive member. These adaptations are costly. These adaptations require the management of a large number of different references. Presentation of the invention

[0004] A first aim of the present invention is to propose a drive mechanism having a greater number of standard parts.

[0005] A second object of the present invention is to reduce the manufacturing cost of a drive mechanism. In particular, the object of the present invention is to reduce the manufacturing cost of a seat height adjustment mechanism. Summary of the invention

[0006] The present invention relates to a drive mechanism capable of moving at least part of a seat, in particular a vehicle seat, the drive mechanism comprising: - a flange provided with a through opening having a first transverse axis, - a centering element comprising a through opening, the centering element being fixed to the flange, the through opening being centered on the first transverse axis; - a drive member passing through the through opening of the flange and the through opening of the centering element, the drive member being able to pivot around the first transverse axis, the drive member comprising a first toothing stage cooperating with the centering element, characterized in that it comprises a second toothing stage having a different shape from the first toothing stage, the second toothing stage being coaxial and integral with the first toothing stage, the second toothing stage being intended to cooperate with a toothed element to drive said at least one seat part in movement. Advantageously, the centering element can be used with different toothed elements. When a manufacturer imposes a new toothed element for a part of a seat, only the second toothing stage of the drive member must be modified.

[0007] The characteristics set out in the following paragraphs can, optionally, be implemented. They can be implemented independently of each other or in combination with each other:

[0008] - the centering element comprises a plate comprising the through opening and a bearing rotatably mounted in the through opening of the plate, the bearing further comprising a disc provided with a central hole and teeth arranged along the inner edge of the central hole, the teeth of the bearing cooperating with the teeth of the first toothing stage; - the plate further comprises a guide collar bordering the through opening, said guide collar being adapted to guide the bearing during its rotation around the first transverse axis; - the drive member is made of metal and the bearing is made of plastic; - the plate comprises a first main face provided with the guide collar, and a second main face opposite the first main face, the second main face comprising a housing open to the outside and surrounding the central opening; the disc being mounted to move in rotation in the housing;

[0009] - the second toothing stage has at least one shape characteristic different from a shape characteristic of the first tooth stage, said shape characteristic being a number of teeth and / or a shape of the teeth and / or different dimensional characteristics; - the different dimensional characteristics include at least one dimension among the pitch, the head diameter, the root diameter, the tooth space dimension, the angle between two opposite flanks forming the tops of the teeth, the root surface and the head surface.

[0010] The invention also relates to a seat, in particular a vehicle seat, comprising: - a drive mechanism shaped according to one of the characteristics mentioned above, - at least one pair of slide elements, - a seat carried by said at least one pair of slide elements, - a backrest carried by the seat, the seat comprising a seat frame, the seat frame comprising said flange extending in a longitudinal direction, a crosspiece extending in a transverse direction, and a toothed element cooperating with the second toothing stage, the rotation of the drive member causing the movement of the seat frame in a vertical direction; - the toothed element comprises at least one connecting rod provided with a toothed sector, the connecting rod being pivotally articulated around a second transverse axis relative to the flange and around a third transverse axis relative to the slide element, the second transverse axis being the pivot axis of the toothed sector; the rotation of the drive member causing the connecting rod to pivot around the second transverse axis and the third transverse axis; - the toothed element includes a rack. Brief description of the figures

[0011] [Fig-1] is a schematic view of a vehicle seat provided with a drive mechanism according to the invention, the drive mechanism being manually actuated, and of a vehicle seat provided with a drive mechanism according to the invention, the drive mechanism being motorized;

[0012] [Fig.2] is a perspective view of a part of a seat frame of a seat according to a first embodiment, the seat frame being provided with a drive mechanism according to the invention;

[0013] [Fig.3] is another perspective view of a portion of the chassis illustrated in [Fig.2];

[0014] [Fig.4] is another perspective view of part of a chassis illustrated in the [Fig.2] in which the drive mechanism is partially torn off;

[0015] [Fig.5] is a perspective view of a drive member of a drive mechanism according to the invention;

[0016] [Fig.6] is a perspective view of the drive member assembled to a centering element of a drive mechanism according to the invention;

[0017] [Fig.7] is an exploded perspective view of the drive member and centering element shown in [Fig.6];

[0018] [Fig.8] is a perspective view of a part of a seat frame of a seat according to a second embodiment, the seat frame being provided with a drive mechanism according to the invention. Detailed description of the invention

[0019] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "rear", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures or of the seat in its normal position of use.

[0020] In the following, the longitudinal direction X means the longitudinal direction of the seat. The longitudinal direction of the seat is considered to be the same as the longitudinal direction of the motor vehicle in which the seat is mounted. This longitudinal direction corresponds to the normal direction of travel of the vehicle. The longitudinal direction X is preferably horizontal. The transverse direction Y is the transverse direction of the seat. The transverse direction Y of the seat thus corresponds to the transverse or lateral direction of the motor vehicle. This transverse direction Y corresponds to a direction perpendicular to the normal direction of travel of the vehicle. The transverse direction Y is preferably horizontal. Finally, the vertical direction Z is a vertical direction of the seat, perpendicular to the longitudinal directions X and transverse directions Y.

[0021] [Fig.l] represents a vehicle seat 2 which comprises a seat 6 and a backrest 4 carried by the seat 6, two pairs of slide elements 10, mounted on the floor 8 of the vehicle.

[0022] The pairs of slide elements 10 extend in a longitudinal direction X. One slide element of each pair is slidably mounted in another slide element of the same pair.

[0023] The seat 6 comprises a seat frame 20 shown partially in [Fig. 2]. The seat frame 20 comprises two flanges 22 each extending in the longitudinal direction X and comprising, in the transverse direction Y, an inner side 24 and an outer side 26. The seat frame 20 comprises at least one tubular crosspiece 28 extending in the transverse direction and secured to each side of each of the flanges. With reference to [Fig. 4], the flanges 22 comprise a through opening 29 arranged around the first transverse axis AL

[0024] The seat frame 20 further comprises toothed elements 30 arranged on the inner side 24 of the flanges in the transverse direction. In the embodiment illustrated in FIGS. 2 to 4, the toothed elements 30 are articulated connecting rods 32 pivoting on the crosspiece 28 around a second transverse axis A2 relative to the flanges. The connecting rods 32 each comprise a toothed sector 34 capable of pivoting around a point of the second transverse axis A2. The connecting rods 32 are further articulated around a third transverse axis A3 to a fixed part in height of an element of the pair of slide elements 10. The fixed part in height of this element has not been shown in the figures.

[0025] The seat 2 further comprises a drive mechanism 12 connected to the seat allowing the height of the seat to be adjusted. The drive mechanism 12 can be driven by a control lever 16 pivotally mounted about a transverse horizontal rotation axis as illustrated in [Fig. 1]. The drive mechanism 12 can also be motorized and actuated by an actuator 18. The drive mechanism 12 comprises a first housing 36 arranged on the inner side 24 of the flange in the transverse direction. The first housing 36 comprises a main wall 38 extending substantially perpendicular to the transverse direction Y. The main wall 38 comprises a cap 40 extending in the transverse direction Y in a direction oriented towards the side opposite the flange 22. The cap 40 is provided with an opening 42. The toothed sector 34 of the connecting rod is arranged transversely between the main wall 38 and the inner side 24 of the flange.

[0026] With reference to Figures 3 and 4, the drive mechanism 12 comprises a second housing 44 arranged on the outer side 26 of the flange in the transverse direction, and an adjustment mechanism 46 housed in the second housing 44. The adjustment mechanism 46 is known per se. It has not been shown in detail and will not be described. An example of an adjustment mechanism is described in patent FR 2809355 filed in the name of the applicant.

[0027] The drive mechanism 12 further comprises a centering element 48 and a drive member 50.

[0028] The centering element 48 is arranged transversely between the second housing 44 and the outer side 36 of the flange 22. The centering element 48 serves to guide and center the drive member 50. The centering element 48 also allows the first housing 36 to be fixed to the flange 22.

[0029] With reference to Figures 6 and 7, the centering element 48 comprises a plate 52 and a bearing 54.

[0030] The plate 52 comprises a through opening 56 having a center centered on the first transverse axis AL. The plate 52 is fixed to the flange 22 and to the first housing 36, for example by means of bolts. The plate 52 comprises a first main face 58 arranged opposite the external face 26 of the flange. The first main face 58 of the plate comprises a guide collar 60 bordering the through opening 56 and extending in the transverse direction Y in a direction directed towards the first housing 36. The plate comprises a second main face 62 opposite the first main face 58. The second main face 62 comprises a housing 64 open to the outside and surrounding the central opening 56. The bearing 54 is mounted to rotate in the through opening 56 of the plate. The bearing 54 comprises a disc 66 provided with a central hole 68. The disc 66 is housed to rotate in the housing 64. The bearing comprises a plurality of teeth 70. The teeth 70 are distributed regularly around the internal edge of the central hole. The teeth 70 of the bearing comprise a convex internal face and a rounded external face suitable for cooperating with the internal face of the guide collar.

[0031] Preferably, the plate 52 is made of plastic.

[0032] Preferably, the bearing 54 is made of plastic.

[0033] With reference to Figures 4, 5 and 7, the drive member 50 extends along the first transverse axis AL The drive member 50 comprises a splined shaft 72 at one of its ends and a smooth rod 74 at its other end. The splined shaft is housed partly in the housing 64 of the plate of the centering element. The splined shaft 72 is engaged with a splined hole of a ring of the adjustment mechanism 46 so that the drive member 50 is rotated about the first transverse axis Al, when the adjustment mechanism is actuated.

[0034] The drive member 50 extends along the first transverse axis A1 through the central hole 68 of the bearing, the through opening 56 of the flange and the opening 42 of the first housing. The drive member 50 further comprises a first toothing stage 76. The first toothing stage has the shape of a first toothed wheel. The first toothing stage 76 cooperates with the centering element 48. In particular, the teeth of the first toothing stage mesh with the teeth 70 of the bearing 54 of the centering element. The drive member 50 further comprises a second toothing stage 78. The second toothing stage 78 also has the shape of a second toothed wheel. The second toothing stage 78 is coaxial and integral with the first toothing stage. Thus, the first toothed wheel and the second toothed wheel are integral. The first toothed wheel and the second toothed wheel are also coaxial and contiguous.The second toothing stage 78 cooperates with the toothed sector 34 of the connecting rod 32.

[0035] The second toothing stage 78 has a different shape than the first toothing stage 76. In particular, the second toothing stage 78 has at least one shape characteristic different from the shape characteristics of the first toothing stage. The different shape characteristics may for example be the number of teeth and / or the shape of the teeth and / or different dimensional characteristics.

[0036] For example, the dimensional characteristics include at least one of tooth pitch, head diameter, root diameter, the space between two consecutive teeth, the angle between two opposite flanks forming the tops of the teeth, the root surface and the head surface.

[0037] The tooth pitch is the distance between two right flanks or two left flanks of two consecutive teeth. The head diameter is the diameter of a circle that passes through the top of the teeth. The root diameter is the diameter of a circle that passes through the base of the teeth. The dimension between two consecutive teeth is called the tooth spacing.

[0038] The splined shaft and a part of the first toothing stage 76 are arranged on the outer side 26 of the flange. The other part of the first toothing stage 76, the second toothing stage and the smooth rod 74 are arranged on the inner side 24 of the flange. The second toothing stage 78 cooperates with the toothed wheel 34 of the connecting rod 32. The smooth rod 74 is mounted to rotate freely in the opening 42 of the first housing.

[0039] Preferably, the drive member 50 is made of metal.

[0040] In operation, when the adjustment mechanism 12 is manually operated by the lever 16 or by the actuator 18, the drive member 50 is rotated around the first transverse axis AL. The second toothing stage 78 meshes with the toothed sector 34. The connecting rod 32 pivots around the second transverse axis A2 and the third transverse axis A3. The pivoting of the connecting rod 32 causes the raising or lowering of the flanges 22, of the crosspiece 28 and therefore of the seat base 6.

[0041] Alternatively, the toothed element may be a pinion.

[0042] According to a second embodiment, the toothed element is a rack. [Fig. 8] represents a part of a frame of a seat according to this second embodiment of the invention. This second embodiment is identical to the first embodiment of the invention except that the connecting rod 32 has been replaced by a rack 80. The rack is pivotally mounted about an axis transverse to an element of the slide 10.

[0043] When the drive mechanism 12 is actuated, the drive member is rotated about the second transverse axis A2. The second toothing stage 78 of the drive member meshes with the teeth of the rack. The rack pivots and lifts the seat frame of the seat. The drive mechanism 12 according to the invention can also be applied to other movable elements of the seat such as a mechanism for adjusting the height of the headrest.

Claims

Claims

1. Drive mechanism (12) suitable for driving at least part of a seat (2), in particular a vehicle seat, in movement, the drive mechanism (12) comprising: - a flange (22) provided with a through opening (29) having a first transverse axis (A1), - a centering element (48) comprising a through opening (56), the centering element being fixed to the flange, the through opening (56) being centered on the first transverse axis;- a drive member (50) passing through the through opening (29) of the flange and the through opening (56) of the centering element (48), the drive member (50) being able to pivot about the first transverse axis (A1), the drive member comprising a first toothing stage (76) cooperating with the centering element, characterized in that it comprises a second toothing stage (78) having a different shape from the first toothing stage, the second toothing stage being coaxial and integral with the first toothing stage, the second toothing stage (78) being intended to cooperate with a toothed element to drive said at least one seat part in displacement.;

2. A drive mechanism (12) according to claim 1, wherein the centering element (48) comprises a plate (52) having the through opening (56) and a bearing (54) rotatably mounted in the through opening (56) of the plate, the bearing (54) further comprising a disc (66) provided with a central hole (68) and teeth (70) arranged along the inner edge of the central hole, the teeth (70) of the bearing cooperating with the teeth of the first toothing stage (76).

3. Drive mechanism (12) according to claim 2, wherein the plate (52) further comprises a guide collar (60) bordering the through opening (56), said guide collar (60) being adapted to guide the bearing during its rotation around the first transverse axis (Al).

4. A drive mechanism (12) according to any one of claims 2 and 3, wherein the drive member (50) is made of metal and the bearing (54) is made of plastic.

5. A drive mechanism (12) according to claim 3 or 4, wherein the plate (52) has a first main face (62) provided with the guide collar, and a second main face (62) opposite the first main face (58), the second main face (62) comprising a housing (64) open to the outside and surrounding the central opening (56); the disc (66) being mounted to move in rotation in the housing (64).

6. A drive mechanism (12) according to any one of claims 1 to 5, wherein the second tooth stage (78) has at least one shape characteristic different from a shape characteristic of the first tooth stage, said shape characteristic being a number of teeth and / or a shape of the teeth and / or different dimensional characteristics.

7. The drive mechanism (12) of claim 5, wherein the different dimensional characteristics include at least one of pitch, tip diameter, root diameter, tooth gap dimension, angle between two opposite flanks forming the apexes of the teeth, root surface, and tip surface.

8. Seat (2), in particular a vehicle seat, comprising: - a drive mechanism (12) shaped according to any one of claims 1 to 7, - at least one pair of slide elements (10), - a seat (6) carried by said at least one pair of slide elements (10), - a backrest (4) carried by the seat (6), the seat (6) comprising a seat frame (20), the seat frame comprising said flange (22) extending in a longitudinal direction (X), a crosspiece (28) extending in a transverse direction (Y), and a toothed element cooperating with the second toothing stage (78), the rotation of the drive member (50) causing the movement of the seat frame (20) in a vertical direction (Z).

9. Seat (2) according to claim 8, in which the toothed element comprises at least one connecting rod (32) provided with a toothed sector (34), the connecting rod being pivotally articulated about a second transverse axis (A2) relative to the flange (22) and about a third transverse axis (A3) relative to the slide element (10), the second transverse axis (A2) being the pivot axis of the toothed sector (34); the rotation of the drive member (50) driving the 10 pivoting of the connecting rod around the second transverse axis (A2) and the third transverse axis (A3).

10. A seat (2) according to claim 8, wherein the toothed element comprises a rack (80).

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