Forward extension system for a motor vehicle seat

Abstract

The invention relates to a forward extension system for a motor vehicle seat, said system comprising a leg extension comprising a first (5) and a second (6) shelf, said first shelf being rotatably mounted between a retracted and an extended position, said second shelf being slidably mounted between a retracted and an extended position where it extends said first shelf forward, said system further comprising a motorized device for actuating said shelves from one position to the other, said second shelf being mounted on said first shelf by two double slides (19) extending laterally and in a longitudinal direction on either side of said shelves, each of said double slides comprising a first rail (23), a second rail (24), and a sliding support (25) for receiving said first and second rails. Figure 5

Description

Title of the invention: System for extending a motor vehicle seat base forward

[0001] The invention relates to a system for extending a motor vehicle seat base forward, said system being intended to ensure reception in a substantially horizontal position of the legs of an occupant of said seat, and a motor vehicle seat comprising such a system.

[0002] It is known, in particular from document CN114506253-A, to produce a system for extending a motor vehicle seat base forward, said system being intended to ensure reception in a substantially horizontal position of the legs of an occupant of said seat, said system comprising: • an extension for receiving said legs, said extension comprising a first and a second shelf, knowing that: • said first shelf is mounted to rotate around a transverse axis arranged at the front of said seat, said first shelf having a retracted position, where it is located at the front of said seat in a substantially vertical position, and a deployed position reached by rotation upwards, where it extends said seat forwards to arrange the aspect faces of said seat and said first shelf in a substantially coplanar manner, • said second shelf is mounted to slide longitudinally relative to said first shelf, said second shelf having a retracted position, where it is arranged to cover said first shelf, and a deployed position reached by sliding forward, where it extends said first shelf forward to arrange the aspect faces of said shelves in a substantially coplanar manner, • a motorized device for actuating said shelves from one position to another, so as to reversibly move said extension from a retracted configuration to a deployed configuration, said device comprising a first electric geared motor for actuating said first shelf in rotation and a second electric geared motor for actuating said second shelf in longitudinal translation relative to said first shelf.

[0003] A problem arising with such an embodiment is to be able to have a sufficiently long extension to be able to efficiently ensure its function of reception of the legs of an occupant, and this by implementing an arrangement as simple, economical, robust and compact as possible.

[0004] The aim of the invention is to propose an arrangement making it possible to meet these expectations.

[0005] To this end, and according to a first aspect, the invention proposes a system for extending a motor vehicle seat base forward, said system being intended to ensure reception in a substantially horizontal position of the legs of an occupant of said seat, said system comprising: • an extension for receiving said legs, said extension comprising a first and a second shelf, knowing that: • said first shelf is mounted to rotate around a transverse axis arranged at the front of said seat, said first shelf having a retracted position, where it is located at the front of said seat in a substantially vertical position, and a deployed position reached by rotation upwards, where it extends said seat forwards to arrange the aspect faces of said seat and said first shelf in a substantially coplanar manner, • said second shelf is mounted to slide longitudinally relative to said first shelf, said second shelf having a retracted position, where it is arranged to cover said first shelf, and a deployed position reached by sliding forward, where it extends said first shelf forward to arrange the aspect faces of said shelves in a substantially coplanar manner, • a motorized device for actuating said shelves from one position to another, so as to reversibly move said extension from a retracted configuration to a deployed configuration, said device comprising a first electric geared motor for actuating said first shelf in rotation and a second electric geared motor for actuating said second shelf in longitudinal translation relative to said first shelf,

[0006] said second shelf being slidably mounted on said first shelf by two double slides extending laterally and in a longitudinal direction on either side of said shelves, each of said double slides comprising a first rail fixed to said first shelf, a second rail fixed to said second shelf and a support for sliding reception of said first and second rails, so as to allow on the one hand maximum forward deployment of said second shelf when it is put in the deployed position and on the other hand a force recovery to support the weight of the legs of said occupant.

[0007] In this description, the terms of positioning in space (top, longitudinal, transverse, lateral, front, rear, vertical, horizontal, below, etc.) are taken with reference to the system in place in the vehicle, said vehicle extending longitudinally along its length, transversely along its width and vertically along its height.

[0008] With the proposed arrangement, the installation of double slides allows on the one hand a maximized forward deployment of the second shelf when it is placed in the deployed position and on the other hand a recovery of force to support the weight of the legs of the occupant of the seat.

[0009] In the remainder of the description, two embodiments of actuation devices will be detailed, making it possible to optimize, in combination with the double slides, such maximized forward deployment of the second shelf.

[0010] It will be noted here that the use of double slides is necessary in the case of tablets of small longitudinal dimension (measured when the tablets are placed in the deployed position), such a characteristic being usually required so that the extension can be arranged in a retracted configuration without interfering with the environment of the seat.

[0011] It will also be noted that the maximum deployment of the second shelf may be accompanied, where appropriate, by the appearance of a void between said second shelf and the first shelf, in particular in the case where the longitudinal dimension of said second shelf is greater than that of said first shelf.

[0012] According to a second aspect, the invention proposes a vehicle seat comprising such a system.

[0013] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which:

[0014] [Fig. 1a],

[0015] [Fig.lb]and

[0016] [Fig. 1e] are schematic side views of a seat provided with a system according to one embodiment, the extension being in the retracted configuration ([Fig. 1a]), in the process of being deployed ([Fig. 1b]) and in the deployed configuration ([Fig. 1c]),

[0017] [Fig.2] is a detailed schematic perspective view of the actuating device shown schematically in figures 1,

[0018] [Fig.3] is a detailed schematic perspective view of the actuating device of [Fig.2] integrated into a seat seen from below, the extension being in the retracted configuration,

[0019] [Fig.4a],

[0020] [Fig.4b] and

[0021] [Fig.4c] are partial schematic top views of the actuating device detailed in figures 2 and 3, said device being represented in situations corresponding to the retracted position of the second shelf ([Fig.4a]), to its partial deployment ([Fig.4b]) and to its deployed position ([Fig.4c]),

[0022] [Fig.5] is a schematic view in partial section of a seat showing a mode of creation of a double slide,

[0023] [Fig.6a],

[0024] [Fig.6b] and

[0025] [Fig.6c] are partial schematic top views of an actuating device according to another embodiment, said device being represented in situations corresponding to the retracted position of the second shelf ([Fig.6a]), to its partial deployment ([Fig.6b]) and to its deployed position ([Fig.6c]),

[0026] With reference to the figures, a system for extending forwards a seat 2 of a seat 3 of a motor vehicle is described, said system being intended to ensure reception in a substantially horizontal position of the legs of an occupant of said seat, said system comprising: • an extension 4 for receiving said legs, said extension comprising a first 5 and a second 6 shelf, knowing that: • said first shelf is mounted to rotate around a transverse axis 7 arranged at the front of said seat, said first shelf having a retracted position, where it is located at the front of said seat in a substantially vertical position, and a deployed position reached by rotation upwards, where it extends said seat forwards to arrange the aspect faces of said seat 8 and of said first shelf 9a in a substantially coplanar manner, • said second shelf is mounted to slide longitudinally relative to said first shelf, said second shelf having a retracted position, where it is arranged to cover said first shelf, and a deployed position reached by sliding forward, where it extends said first shelf forward to arrange the aspect faces of said shelves 9a, 9b in a substantially coplanar manner, • a motorized device 10 for actuating said shelves from one position to another, so as to reversibly move said extension from a retracted configuration to a deployed configuration, said device comprising a first electric geared motor 11 for actuating said first shelf in rotation and a second electric geared motor 12 actuating said second tablet in longitudinal translation relative to said first tablet,

[0027] said second shelf being slidably mounted on said first shelf by two double slides 19 extending laterally and in a longitudinal direction on either side of said shelves, each of said double slides comprising a first rail 23 fixed to said first shelf, a second rail 24 fixed to said second shelf and a support 25 for receiving said first and second rails in sliding manner, so as to allow on the one hand maximum forward deployment of said second shelf when it is placed in the deployed position and on the other hand a force recovery to support the weight of the legs of said occupant.

[0028] According to the embodiment shown in [Fig.5], a support 25 comprises a first groove 25a slidably receiving the first rail 23 and a second groove 25b slidably receiving the second rail 24.

[0029] According to the embodiment shown in Figures 1 to 4, the actuating device 10 further comprises: • a nut 13 actuated in rotation by the second geared motor 12, said second geared motor being fixed on the second shelf 6, • an internal worm screw 14 extending longitudinally and being fixed by its rear end 15 to the rear of the first shelf 5, • an endless external screw 16, said external screw being provided with a threaded axial channel 17 receiving said internal screw in screwing, the front end of said external screw being provided with a collar 18 so that said nut comes into abutment against said collar when said second geared motor is brought to the end of its forward travel and initiates a joint rotation of said external screw with said nut, said rotation effecting a rearward extraction of said internal screw from said external screw to extend the forward travel of said second shelf.

[0030] In particular, in a manner not shown, the second geared motor 12 and the nut 13 can be mounted in a pendulum manner to be able to move freely according to a transverse clearance and absorb dimensional dispersions, so as to avoid blocking by arching of the actuating device 10.

[0031] According to another embodiment shown in figures 6, the actuating device 10 further comprises: • a first endless screw 23 actuated in rotation by the second geared motor 12, said second geared motor being fixed on the second shelf 6, • a tubular intermediate part 24 provided on one of its ends with an internal nut 25 cooperating with said first screw, so as to allow a sliding of said first endless screw in said intermediate part, said intermediate part being provided on the other of its ends with an external nut 26, • a second hollow worm screw 27 provided with an internal thread 28 cooperating with said external nut, so as to allow sliding of said external nut in said second screw, said second screw being secured by one of its ends 29 to the first shelf 5,

[0032] the threads of said worm screws and said nuts being defined so that the movement of said second shelf forward is done by forward movement of one part of said intermediate part and of said first screw on the other hand.

[0033] In a manner not shown, the second geared motor 12 can, in this embodiment, be mounted in a pendulum manner to be able to move freely according to a transverse clearance and to absorb dimensional dispersions, so as to avoid blocking by buttressing of the actuating device 10.

[0034] As partially shown in the figures, the axis 20 of the geared motor 12 is parallel to that 21 of the endless screws 14, 16, 23, 27 and said geared motor does not protrude substantially from said screws in a longitudinal direction when the extension 4 is in the retracted configuration, in order to minimize the space occupied by said geared motor in said direction.

[0035] Finally, a motor vehicle seat 3 is described comprising a system as previously described, said system being mounted at the front of the seat 2 of said seat.

Claims

1. Claims System for extending forwards a seat (2) of a motor vehicle seat (3), said system being intended to ensure reception in a substantially horizontal position of the legs of an occupant of said seat, said system comprising: • an extension (4) for receiving said legs, said extension comprising a first (5) and a second (6) shelf, knowing that: • said first shelf is mounted to rotate around a transverse axis (7) arranged at the front of said seat, said first shelf having a retracted position, where it is located at the front of said seat in a substantially vertical position, and a deployed position reached by rotation upwards, where it extends said seat forwards to arrange the aspect faces of said seat (8) and of said first shelf (9a) in a substantially coplanar manner, • said second shelf is mounted to slide longitudinally relative to said first shelf, said second shelf having a retracted position, where it is arranged to cover said first shelf, and a deployed position reached by sliding forward, where it extends said first shelf forward to arrange the aspect faces of said shelves (9a, 9b) in a substantially coplanar manner, • a motorized device (10) for actuating said shelves from one position to another, so as to reversibly move said extension from a retracted configuration to a deployed configuration, said device comprising a first electric geared motor (11) for actuating said first shelf in rotation and a second electric geared motor (12) for actuating said second shelf in longitudinal translation relative to said first shelf, said system being characterized in that said second shelf is slidably mounted on said first shelf by two double slides (19) extending laterally and in a longitudinal direction on either side of said shelves, each of said double slides comprising a first rail (23) fixed to said first shelf, a second rail (24) fixed to said second shelf and a support (25) for sliding reception of said first and second rails, so as to allow on the one hand maximum forward deployment of said second shelf when it is placed in the deployed position and on the other hand a force recovery to support the weight of the legs of said occupant.

2. System according to claim 1, characterized in that a support (25) comprises a first groove (25a) slidably receiving the first rail (23) and a second groove (25b) slidably receiving the second rail (24).

3. System according to any one of claims 1 or 2, characterized in that the actuating device (10) further comprises: • a nut (13) actuated in rotation by the second geared motor (12), said second geared motor being fixed on the second shelf (6), • an internal worm screw (14) extending longitudinally and being fixed by its rear end (15) to the rear of the first shelf (5), • an external worm screw (16), said external screw being provided with a threaded axial channel (17) receiving said internal screw in screwing, the front end of said external screw being provided with a collar (18) so that said nut comes into abutment against said collar when said second geared motor is brought to the end of its forward travel and initiates a joint rotation of said external screw with said nut,said rotation effecting a rearward extraction of said internal screw out of said external screw to extend the forward stroke of said second tablet.,

4. System according to claim 3, characterized in that the second geared motor (12) and the nut (13) are mounted in a pendulum manner to be able to move freely according to a transverse clearance and absorb dimensional dispersions, so as to avoid blocking by arching of the actuating device (10).

5. System according to any one of claims 1 or 2, characterized in that the actuating device (10) further comprises: • a first endless screw (23) actuated in rotation by the second geared motor (12), said second geared motor being fixed on the second shelf (6), • a tubular intermediate part (24) provided on one of its ends with an internal nut (25) cooperating with said first screw, so as to allow sliding of said first endless screw in said intermediate part, said intermediate part being provided on the other of its ends with an external nut (26), • a second hollow endless screw (27) provided with an internal thread (28) cooperating with said external nut, so as to allow sliding of said external nut in said second screw, said second screw being secured by one of its ends (29) to the first shelf (5),the threads of said worm screws and said nuts being defined so that the movement of said second shelf forward is done by moving forward on the one hand said intermediate part and on the other hand said first screw.,

6. System according to claim 5, characterized in that the second geared motor (12) is mounted in a pendulum manner to be able to move freely according to a transverse clearance and to absorb dimensional dispersions, so as to avoid blocking by arching of the actuating device (10).

7. System according to any one of the preceding claims, characterized in that the axis (20) of the geared motor (12) is parallel to that (21) of the endless screws (14, 16, 23, 27) and in that said geared motor does not protrude substantially from said screws in a longitudinal direction when the extension (4) is in the retracted configuration, in order to minimize the space occupied by said geared motor in said direction. 10

8. Motor vehicle seat (3) comprising a system according to any one of the preceding claims, said system being mounted at the front of the seat (2) of said seat.

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