FR2952866A1 - Device for regulating e.g. armrest, with respect to fixed support of seat of motor vehicle in translation, has control unit displacing cage with respect to sleeve in unlocked position in which locking body is displaced with respect to pin - Google Patents

Abstract

The device has a truncated sleeve (20) integrated with a support and an adjustable element (2). A cage (22) is equipped with a locking body (24) and arranged in the sleeve. The cage slides around pins (4, 6) of the support or the adjustable element. A control unit (14) displaces the cage axially with respect to the sleeve between locked position in which the sleeve pushes the locking body against the pin and unlocked position in which the locking body is free to displace radially with respect to the pin.

Description

B9881 - 2767 1.EN 1 ADJUSTMENT IN TRANSLATION OF AN ADJUSTABLE ELEMENT FOR MOTOR VEHICLE SEAT

Field of the Invention The present invention relates to the field of seats for a motor vehicle. It relates more particularly the headrests, the armrests as well as the nose cushion cushions. DISCUSSION OF THE PRIOR ART For height adjustment of a headrest relative to a motor vehicle seatback, it is known to use a system of sliding pins in guide bushes. The system also comprises locking means to maintain the adjustment height chosen by the user and to maintain the neck of the passenger in case of impact. The pin carries notches in which a lock engages. Such a system does not allow a continuous and therefore precise adjustment of the headrest. FR-A-2881694 discloses a headrest adjustment system comprising two pins connected to the seat on which slide guide bearings connected to a frame of the headrest. The blocking of the height position of the headrest is obtained by a so-called bracing mechanism which consists of tilting bent wires in a plane B9881 - 2767 1.EN

2 perpendicular to the direction of the pins. In this way, the sockets jam the pins. However, the quality of the lock in the position desired by the user is dependent on the surface condition of the pins and sockets. However, the manipulation of the headrest by the user introduces pollution in the form of fat due to the sweat released by his hands. The adhesion of the bushings on the pins therefore degrades over time. The headrest eventually no longer hold the set position, which affects the safety in case of shock. In addition, the vibrations of the vehicle tend to lower the headrest. Moreover, one can not make such a compact locking system. Indeed, the distance between the two pins is important. In addition, if the diameter of the pins is reduced, the bracing is made difficult.

There is therefore a need for a more reliable adjustment device. Summary An object of an embodiment of the present invention is to provide a device for adjusting a headrest that overcomes the disadvantages of conventional systems. More generally, an embodiment of the present invention aims at a device for adjusting in translation of an adjustable element of a seat avoiding at least some of the disadvantages of prior adjustment devices, the adjustable element being able for example to be a support head, an armrest or a seat cushion nose. Thus, an embodiment of the present invention provides a device for adjusting in translation of an adjustable element relative to a fixed support of a motor vehicle seat, comprising: a frustoconical sleeve integral with the support or the element; a cage provided with locking body, the cage being housed in the sleeve and being able to slide around a pin of the support or the element; B9881 - 2767 1.EN

3 a control member adapted to move the cage axially relative to the sleeve, between a locked position in which the sleeve pushes the locking bodies against the pin and an unlocked position in which the locking bodies are free to move radially relative to on the spit. According to another embodiment of the present invention, the support and the adjustable element can be moved away from each other without action on the control member.

According to another embodiment of the present invention, the device comprises an elastic return element capable of ensuring the transition from the unlocked position to the locked position. According to another embodiment of the present invention, the sheath is a truncated cone and the locking bodies are balls. According to another embodiment of the present invention, the sheath is a truncated pyramid and the locking bodies are rollers, the spindle comprising flats. According to another embodiment of the present invention, the sleeve is a truncated pyramid and the locking bodies are diabolos, the pin being of substantially circular section. According to another embodiment of the present invention, the control member is a rod comprising notches capable of cooperating with cage pins. Another embodiment of the present invention provides a headrest for a motor vehicle seat comprising at least one device as described above. Another embodiment of the present invention provides an armrest for a motor vehicle seat comprising a movable part and at least one device as described above.

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Another embodiment of the present invention provides a seat for a motor vehicle seat comprising a seat cushion nose and at least one device as described above.

Another embodiment of the present invention provides a seat for a motor vehicle comprising at least one headrest as described above and / or at least one armrest as described above and / or a seat as described above. . BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features, and advantages will be set forth in detail in the following description of particular embodiments in a non-limitative manner with reference to the accompanying drawings in which: FIG. schematic of a headrest mounted on a motor vehicle seat back; Figure 2 is a schematic sectional view of a vertically adjustable headrest in a locked position, according to a first embodiment of the present invention; Figure 3 is a schematic sectional view of a vertically adjustable headrest in unlocked position, according to the first embodiment of the present invention; Figure 4 is an enlargement of a detail of Figure 2; Figure 5 is an enlargement of the same detail in the configuration of Figure 3; Figure 6 is a partial enlargement of a detail of Figure 2, according to a variant; Figure 7 is a partial enlargement of the same detail, according to another variant; Figure 8 is a schematic sectional view of a longitudinally adjustable headrest according to a second embodiment of the present invention; Figure 9 is a schematic perspective view of a seat cushion nose longitudinally adjustable; and B9881 - 2767 1.EN

Figure 10 is a schematic perspective view of a longitudinally adjustable armrest. DETAILED DESCRIPTION For the sake of clarity, the same elements have been designated with the same references in the various figures and have been drawn without respect of scale. FIG. 1 is a diagrammatic perspective and partial view of a seat back 1 for a motor vehicle on which a headrest 2 is mounted. The headrest 2 comprises two pins 4 and 6 respectively defining vertical axes Z1- Z1 and Z2-Z2. The free ends of the pins are engaged in the upper part of the folder and are fixed thereto. For example, the pins are tubular circular section. The pins 4 and 6 are connected in the upper part by a crosspiece 8. The cross member 8 can be reported between the two pins 4 and 6. Alternatively, it is possible to envisage a single U-shaped piece. The headrest 2 is slidably mounted on the pins 4 and 6 via an adjusting device symbolized by a housing 10 shown in dashed lines. The headrest 2 comprises an actuating button 12 integral with a control member 14, for example a rod, adapted to cooperate with the adjustment device 10, as will be explained below. Figures 2 and 3 illustrate a height adjustable headrest and a first embodiment of the adjustment mechanism. Figure 2 is a vertical sectional view of the headrest 2. The adjustment device 10 comprises for example two frustoconical sleeves 20 integral with the headrest 2, each of the sleeves being traversed by a pin 4 or 6. In each of the sleeves 20 is housed a cage 22 comprising at least two locking bodies 24, for example balls. In their upper parts, the cages comprise a number of through radial apertures corresponding to the number of balls 24. Each of the openings is defined so that the ball 24 B9881 - 2767 1.EN

6 protrudes from the spindle side and the sheath side. Each of the cages 22 is traversed by a pin 4 or 6. The sleeve 20 has a truncated cone shape and the cage 22 a sleeve shape. In each of the cages 22 is housed a return spring 26 towards the part of the sleeve of smaller section. The spring rests on a bottom 28 of the sheath 20. The spring 26 works in compression between the cage 22 and the sheath 20. Any other elastic return means can be envisaged. The control rod 14 has been shown only partially. The cooperation between the rod 14 and each of the cages 22 will be explained below. In Figure 2, each of the cages 22 is, under the effect of the spring 26, disposed in the sleeve 20 so that the balls 24 are wedged between the inner wall of the sleeve and a pin. The sheath pushing the balls against the spindle, the headrest 2 can not slide relative to the spindle. In particular, any pressure tending to lower the headrest, increases the blockage. The headrest can however be adjusted upwards by pulling it upwards. The headrest 2 is in a so-called locked configuration. In the locking position, the ball mechanism substantially alleviates a risk of microglossing due to vibrations. Figure 3 is a vertical sectional view of the headrest 2 in a so-called unlocked configuration. In this position, the rod 14 forces the cages 22 downwards against the spring 26. The balls 24 are then not in contact with the inner wall of the sleeve 20. The balls are therefore free to move radially relative to the at the cage, the radial direction being in a plane substantially perpendicular to the axes Z1-Z1 and Z2-Z2. Figure 4 is a partial enlargement of detail IV of Figure 2 showing the cooperation between the rod 14 and a cage 22 in the locked position.

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Figure 5 is a partial enlargement of the detail V of Figure 3 showing the cooperation between the rod 14 and a cage 22 in an unlocked position. The rod 14 comprises for example two notches 30 (one at a height approximately of each cage) each comprising an inclined face 32 adapted to cooperate with a pin 34 projecting from the cage 22. The pin 34 extends from the cage substantially transversely relative to the axis of the rod 14. The parts of the rod 14 disposed on either side of the notch are connected by a bridge 36. To prevent twisting of the rod 14, the pin structure 34 - notch Pan 32 is present on both sides of the cage. To adjust the position downwards, the button 12 is pressed. The button drives the actuating rod 14 in a direction perpendicular to the axes Z1-Z1 and Z2-Z2 (in the direction of the arrow F1). Each of the inclined faces 32 of the rod 14 comes into contact with each of the pins 34 of the cages 22. By maintaining the pressure on the button 12, the rod 14 continues to advance along the arrow F1. The inclined faces 32 slide along each of the pins 34. The cages 22 are then driven towards the back 1 (downwards) according to the arrow F2, as shown in Figure 5. The spring 26 (not shown) is compressed and the balls 24 are no longer in contact with the inner wall of the sleeve 20. The pins 4 and 6 can therefore slide relative to the sleeves 20 and therefore relative to the headrest 2. It can then be adjusted continues in height the position of the headrest 2. When release button 12, the spring 26 relaxes to bring the cage 22 in its locking position, namely in the position in which the balls 24 are in contact With the sleeve 20. In the locked position, the headrest 2 can be moved away from the backrest 1 without having to actuate the control means 14. If it is desired to bring the two parts 1 and 2 closer without forcing, the user must press the button 12. Indeed, the B9881 - 2767 1.EN

8 resistance to movement is lower in a direction away from the two parts than in a direction of approximation. When the headrest 2 is moved away from the backrest 1, the sleeves 20 move relative to the cages 22. The pins 4 and 6 can then slide. In a variant, the cages 22 each comprise an outer annular groove with a cutaway cooperating with a control rod comprising recessed portions surrounding the cages. Part of each portion is adapted to be housed at least partly in the annular groove. Figures 4 and 5 illustrate a mechanical cooperation between the rod 14 and the cage 22. It can also provide a magnetic cooperation between these two elements. For example, the cages 22 can be moved by an electromechanical actuator or by a motor. Figure 6 is a partial enlargement of detail VI of Figure 2 showing a variant of cooperation between a pin and the locking bodies. The locking bodies 24 are rollers. The pin 4 comprises a flat portion 36 disposed on either side of the pin, the flats extending vertically along the axis Z1-Z1 on the adjustment height. Figure 7 is a partial enlargement of the same detail VI of Figure 2 showing another variant of cooperation between a pin and the locking bodies. The locking bodies 24 are diabolos and the pins 4 and 6 are of substantially circular section. If the locking bodies 24 are rollers or diabolos, the sheath 20 may have a truncated pyramid shape and the cage 22 may be a tubular piece with a square or rectangular section. Figure 8 shows a longitudinally adjustable headrest 40 and another embodiment of the adjustment mechanism. The headrest 40 comprises a support 42 connected to the backrest by pins 44. The headrest 40 also includes a B9881 - 2767 1.FR

9 moving part 45 relative to the support 42 comprising one or more pins 46 of longitudinal axis X1-X1 providing the connection with the support 42. The head of the driver or the passenger of the motor vehicle is likely to rest on the part 45. The support 42 comprises a device 48 for translational adjustment of the portion 45 along the longitudinal axis X1-X1. The device 48 comprises a cage 22 comprising balls 24. The cage 22, housed in a sheath 20, also comprises a spring 26 resting on the bottom 28 of the sheath. Following pressing on a button not shown, an actuation rod is also not shown. The button and the rod may be identical to the button 12 and the rod 14 of the previous embodiment. Following the intervention of the user, the cage 22 can then move longitudinally in the direction of the movable portion 45 in the direction of the arrow F4. As indicated above, the pin 46 secured to the portion 45 is thus released and can slide relative to the sleeve 20, so relative to the fixed portion 42 of the headrest. When the user considers that the portion 45 is in a proper position, he releases the button. The spring 26 relaxes and drives the cage 22 in the opposite direction to the arrow F4. The balls 24 are in contact with the sheath 20 and thus block the movement of the pin 46. The portion 45 is in a locked configuration as shown in FIG. 8. As a variant, it is possible to integrate the adjustment device in FIG. the movable part 45. Similarly, in the embodiment of FIGS. 2 and 3, the adjustment device can be in the backrest 1. The embodiments of FIGS. 2-3 and 8 are combinable and can be applied to head restraints for front and rear seats. Figure 9 is a perspective view of a cushion seat 60 including a seat cushion nose 62 capable

10 to move along an axis X2-X2 relative to the seat 60. The cushion nose 62 slides along two pins 64 and 66 secured to the cushion 60. It is expected to have in the nose cushion 62 two devices of translation adjustment as previously described. Alternatively, the adjustment devices may be arranged in the seat 60. FIG. 10 is a perspective view of an armrest 70 comprising a fixed part 71 and a movable part 72 adapted to move along an axis X3. -X3 relative to the fixed portion 71. The fixed portion 71 is secured to the backrest by an axis 75. The movable portion 72 slides along a pin 74 fixed to the fixed portion 71 and extending along an approximately parallel axis to the X3-X3 axis. To ensure the adjustment of the portion 72 relative to the fixed portion 71, provision is made in the portion 72 a translation adjustment device as described above. Alternatively, the adjusting device may be disposed in the fixed part 71. It is conceivable to provide the fixed part with a second spindle. Particular embodiments of the present invention have been described. Various variations and modifications will be apparent to those skilled in the art. In particular, the locking bodies may be steel, bronze, brass, aluminum, plastic, etc. It is also conceivable to use composite locking bodies whose steel core is covered with a plastic coating. The practical implementation of the invention is within the abilities of those skilled in the art from the functional description given above. In particular, those skilled in the art can determine in particular the diameter of the locking bodies, the angle at the top of the frustoconical sheath and the materials to be used to ensure proper operation of the adjustment device and allow an effective reversible passage between the position locked and the unlocked position. A study on these various parameters makes it possible in particular to reduce the diameter of the pins as well as B9881 - 2767 1.EN

11 the spacing between the two pins 4 and 6. We thus obtain compact adjustable elements.

Claims (11)

REVENDICATIONS1. Device (10; 48) for translational adjustment of an adjustable element (2; 45; 62; 72) relative to a fixed support (1; 42; 60; 71) of a motor vehicle seat, comprising: a frustoconical sheath (20) integral with the support or the element; a cage (22) provided with locking body (24), the cage being housed in the sleeve and being able to slide around a pin (4, 6; 46; 64, 66; 74) of the support or the element; a control member (14) adapted to move the cage axially with respect to the sleeve, between a locked position in which the sleeve pushes the locking bodies against the pin and an unlocked position in which the locking bodies are free to move radially. relative to the spindle. 2. Device according to claim 1, wherein the support (1; 42; 60) and the adjustable element (2; 45; 62) can be moved away from each other without action on the control member. (14). 3. Device according to claim 1 or 2, comprising an elastic return element (26) adapted to ensure the transition from the unlocked position to the locked position. 4. Device according to any one of claims 1 to 3, wherein the sheath (20) is a truncated cone and the locking bodies are balls (24). 5. Device according to any one of claims 1 to 3, wherein the sleeve is a truncated pyramid and the locking bodies are rollers, the pin (4) comprising flats (36). 6. Device according to any one of claims 1 to 3, wherein the sleeve is a truncated pyramid and the locking bodies are diabolos, the pin (4) being substantially circular section.B9881 - 2767 1.EN 13 7. Device according to any one of claims 1 to 6, wherein the control member (14) is a rod comprising notches (30) adapted to cooperate with pins (34) of the cages (22). Headrest (2) for a motor vehicle seat comprising at least one device according to any one of claims 1 to 7. 9. Armrest (70) for a motor vehicle seat comprising a movable part (72) and at least one device 10 according to any one of claims 1 to 7. 10. Seat (60) for a motor vehicle seat comprising a seat cushion nose (62) and at least one device according to any one of claims 1 to 7. 11. Seat for a motor vehicle comprising at least 15 a headrest according to claim 8 and / or at least one armrest according to claim 9 and / or a seat according to claim 10.