Seat belt buckle attachment device

Abstract

The invention relates to a fastening device (100) for a seat belt buckle (52), comprising: - a loop (110) including a clasp (112) adapted to receive said buckle, - a rigid stem (120), and - a sliding mounting system (101) for the clasp (112) along said stem, which is adapted to block said sliding when a tensile force (F1) exceeding a threshold is exerted on the clasp. According to the invention, the sliding mounting system comprises: - a sleeve (111) coupled to the clasp and housing the stem, - a means for coupling the sleeve to a seat base, - two clamping means (140) located on either side of the stem and movable between a clamping position of the stem and a rest position in which the stem can slide relative to the sleeve, and - means for returning the clamping means to the rest position. Figure for the abstract: Fig. 2

Description

Title of the invention: Seat belt buckle attachment device Technical field of the invention

[0001] The present invention relates generally to the safety of the occupants of a motor vehicle.

[0002] It relates more particularly to an attachment device for a safety belt buckle of a motor vehicle seat, comprising: - a clasp adapted to receive said seat belt buckle, - a rod suitable for mounting on a rigid structure of the motor vehicle, and - a sliding mobile mounting system for the clasp along said stem, which is adapted to block said sliding when a tensile force exceeding a threshold is exerted on the clasp.

[0003] It also relates to a seat equipped with such a fastening device and a vehicle equipped with such a seat. State of the art

[0004] It is known to mount the front seats of a motor vehicle with a sliding mobility from front to back and a movement mobility from top to bottom.

[0005] Such a seat generally comprises a seat, a sliding system consisting of two parallel fixed rails which are fixed to the floor, two movable rails which are able to slide along the two aforementioned rails, and raising means which connect the seat to the movable rails and which allow the height of the seat to be adjusted relative to the floor.

[0006] These raising means are generally made up of two pairs of front and rear connecting rods linking the two movable rails to the seat so as to form two deformable parallelograms.

[0007] Such a seat is equipped with a safety belt loop having a foot and, at its upper end, a clasp suitable for receiving and locking the bolt of a safety belt buckle.

[0008] This loop must be fixed to the floor or seat rails to withstand regulatory stresses in the event of an accident. It is clear that if it were fixed to the seat structure, both the seat structure and the connecting rods would have to be dimensioned to withstand the aforementioned stresses, making the seat particularly heavy and expensive to produce.

[0009] The drawback is that the clasp does not follow the vertical movement of the seat structure, which impairs the overall ergonomics of the vehicle. Indeed, when The seat is in the raised position, and the buckle is located too low to be easily accessible. Furthermore, when the seat occupant has fastened their seatbelt and tries to raise the seat, the seat tightens around their pelvis and prevents them from doing so.

[0010] To address this issue, patent US20140265503 discloses a seat whose loop strap includes a foot and a clasp, but whose lower end of the foot is coupled to the seat structure so as to follow the vertical movement of the latter. More specifically, this lower end is housed in a casing fixed to the seat. This same casing is traversed by a rigid rod that extends parallel to the foot, and whose lower end is hinged to one of the movable rails. A spring is sandwiched between the rigid rod and the foot to keep them apart, particularly when the seat and the loop strap rise, and the casing slides along the rigid rod. Conversely, when a tensile force exceeding a threshold is exerted on the loop strap (typically in the event of an accident), the spring compresses so that the foot comes to rest against a toothed portion of the movable rod.This toothed portion then allows the rigid rod to be locked in the case, so that the tensile force is transmitted directly from the clasp to the moving rail, via the rigid rod.

[0011] The disadvantage of this system is that it may happen that the cooperation between the foot and the toothed portion of the rigid rod does not occur satisfactorily.

[0012] In addition, the rigid rod has the disadvantage of protruding above the seat when the latter is in a low position, this prominence then proving to be at the very least annoying and potentially dangerous for the passenger wishing to sit on the seat. Presentation of the invention

[0013] In order to remedy the aforementioned drawbacks of the prior art, the present invention proposes a coaxial and telescopic system, in which the rod is engaged in a sheath.

[0014] More particularly, the invention proposes an attachment device as defined in the introduction, in which the sliding, movable mounting system of the loop strand along the stem comprises: - a sheath which is coupled to the clasp, which houses at least part of said stem and which is adapted to slide along said stem, - a means of coupling the sheath to a movable, vertical part of a motor vehicle seat - two means for clamping the rod, located on either side of the rod, at least one of which is mounted movable relative to the sleeve between a position of a clamping position in which the two clamping means block the sliding of the rod relative to the sleeve, and a rest position in which they release the sliding of the rod relative to the sleeve, and - elastic return means for the clamping means in the rest position.

[0015] Thus, thanks to the invention, the base of the loop forms a sheath on the stem, so that the latter is neither visible nor bothersome to the seat occupant. To achieve this, the mounting system for the sliding clasp on the stem includes, in addition to this sheath, self-locking means that prevent the sheath from sliding on the stem in the event of an accident.

[0016] It can be noted that in such a device, the angular movement of the sleeve is very small, so that it is possible to integrate the entire device (except for the clasp) inside the seat upholstery (or even within the seat frame). This device is therefore compact, aesthetically pleasing, and does not require surface treatment (varnish, etc.) since it remains largely invisible.

[0017] If the loop strand is equipped with a locking sensor and an electrical connection wire for this sensor, the latter can then also be hidden within the seat.

[0018] Other advantageous and non-limiting features of the attachment device according to the invention, taken individually or in all technically possible combinations, are as follows: - the coupling means is fusible and is adapted to fail when said tensile force exceeds a breaking threshold; - the sheath has two arms that extend on either side of two sides of the shaft and the sheath is open on two other sides of the shaft; - the clamping means comprise two pucks sandwiched between two faces carried respectively by the sleeve and by the coupling means, the two faces having shapes such that, in the rest position, the sleeve extends either at a distance from the rod, or in sliding contact against the rod, and that, in the clamping position, the pucks block the sleeve in tight contact against the rod; - at least one of the two said faces forms a cradle to hold the puck in its resting position, which extends into a ramp inclined relative to the stem; - the pallets are shaped to be extracted from the cradles and slide against the inclined ramps when the traction force is greater than said threshold; - the clamping means comprise two movable cams rotating between the rest position, where they extend either at a distance from the rod or in sliding contact against the rod, and the clamping position where they extend in tight contact against the rod; - the coupling means includes a finger engaged in an opening which is provided in the sleeve and whose shape allows the coupling means to slide relative to the sleeve; - the cams are equipped with latches which are adapted to come to rest against the coupling means when the traction force is greater than said threshold to force the cams to pivot into the jamming position;

[0019] The invention also proposes a motor vehicle seat adapted to be mounted on a floor of the motor vehicle, comprising a seat, a backrest, a height adjustment system allowing the height of the seat to be varied relative to the floor, and a fastening device as mentioned above.

[0020] Preferably, the seat includes a sliding system comprising two fixed rails adapted to be fixed to the floor, two movable rails mounted to slide on the two fixed rails, a locking device for the sliding of the movable rails relative to the fixed rails, and means for deactivating the locking means, the rod being mounted on one of the movable rails.

[0021] The invention also proposes a motor vehicle comprising a floor and a seat as above.

[0022] Of course, the various features, variants, and embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. Detailed description of the invention

[0023] The following description with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0024] On the attached drawings:

[0025] [Fig.1] is a schematic view of a seat according to the invention, illustrated in two different configurations;

[0026] [Fig.2] is a schematic view of a first embodiment of the seat attachment device of [Fig.1], seen from the side and in section along a plane AA;

[0027] [Fig.3] represents schematic side and top views of a clamping means for the hooking device of the [Fig.2];

[0028] [Fig.4] is a detail view of area II of [Fig.2];

[0029] [Fig.5] is a schematic view of a second embodiment of the device seat attachment of the [Fig.l], seen from the side and in section according to a BB plan;

[0030] [Fig.6] is a detailed view of area V of [Fig.5], when the device is in the rest position;

[0031] [Fig.7] is a detail view of half of area V of [Fig.5], when the device is in the jammed position.

[0032] A motor vehicle (car, bus, truck, boat, airplane, etc.) generally comprises a chassis and bodywork elements which together define a passenger compartment. Here, we will consider the vehicle to be a car.

[0033] Figure 1 shows a seat intended to be installed in the passenger compartment of a such a motor vehicle and to be fixed to the chassis of this motor vehicle, and more specifically to the floor 2 of this motor vehicle.

[0034] In the following description, the terms "front" and "rear" will be used in relation to the motor vehicle, the front part of an element designating the part of that element which is located on the side of the hood of the vehicle and the rear part designating the part of that element which is located on the opposite side.

[0035] The terms "lower" (or "bottom") and "upper" (or "top") shall be used in the same way, the lower part of an element designating the part of that element which is located on the floor side 2 of the vehicle and the upper part designating the part of that element which is located on the roof side of the vehicle.

[0036] The adjective "longitudinal" shall apply to a direction or axis oriented from the front to the rear of the vehicle, parallel to the direction of travel of the vehicle when the steering wheel is in the neutral position.

[0037] The adjective "transverse" shall apply to a direction or axis oriented orthogonally to the longitudinal and horizontal axes when the vehicle is traveling on a horizontal road.

[0038] The terms “internal” and “external” will be used to designate respectively the sides of an element facing towards the seat and the opposite.

[0039] The term "articulated" will be used to designate a coupling between two elements without translational mobility, but with at least rotational mobility. In practice, it will hereafter refer to a coupling by simple pivot joint. However, alternatively, it could also refer to a ball joint.

[0040] An articulation can be obtained in various ways. For example, it can be operated by a screw which passes through an opening provided in one of the elements and which screws into the second element, in which case a tube (called a bearing) or a bearing (ball, needle, etc.) will be provided between the screw and the opening to ensure the freedom of pivoting of the two elements relative to each other.

[0041] As shown in [Fig.1], the seat 1 classically comprises a seat 10 and a backrest 20, each comprising a frame and upholstery attached to the frame.

[0042] Each of these frames is, for example, formed of metal parts (not shown) fixed together. Here, it will be considered that the frame of the backrest 20 and the frame of the seat 10 each have two metal side panels, rigidly connected together by metal connecting elements. Of course, alternatively, these frames could be in other forms, for example, plastic shells.

[0043] In the context of the invention, the seat 10 is designed to be mounted movably in height on the floor 2, between low (shown as a solid line) and high (shown as a dashed line) positions. Seat 1 has a riser system 30 for this purpose.

[0044] Preferably, the seat 10 is also provided to be mounted mobilously from front to back on the floor 2. The seat 1 has for this purpose a sliding system 40.

[0045] These riser 30 and slide 40 systems are well known. They could take on a wide variety of forms. One embodiment of these systems can be briefly described here by way of example.

[0046] In this embodiment, the sliding system 40 comprises two fixed rails 41 extending longitudinally, parallel to each other, on the floor 2. These two fixed rails 41 are equipped with means for fixing to the floor. In practice, they can be fitted with screws for fixing to the floor.

[0047] The slide system 40 further comprises two movable rails 42 which are respectively mounted to slide on the two fixed rails 4L. These fixed and movable rails have shapes such that the only degree of freedom of the movable rails 42 with respect to the fixed rails 41 is a sliding movement along a longitudinal axis.

[0048] The slide system 40 also includes means for blocking this sliding mobility, formed for example by a notched accessory (not shown), mounted movably on at least one of the movable rails and adapted to hook onto notches provided in correspondence on the associated fixed rail.

[0049] A means of operating this notched accessory, such as a lever accessible to the occupant of the seat 1, then allows, when the occupant of the seat wishes to move his seat 1 forward or backward, the notches of this accessory to be moved away from those of the fixed rail to free the sliding mobility of the seat 10.

[0050] Alternatively, the sliding system could be motorized.

[0051] In the illustrated example, the raising system 30 comprises two pairs of connecting rods 31, 32. Each connecting rod 31, 32 is articulated, on one side, to one of the movable rails 42 and, on the other, to one of the lateral sides of the base reinforcement 10, around a transverse axis. The two connecting rods 31, 32 of each pair extend substantially parallel to each other between one of the movable rails 42 and one of the lateral sides, so as to form with them a kind of deformable parallelogram. Thus, the base 10 can move relative to the floor 2 in a so-called rotary translational movement, in which the base maintains a substantially constant inclination and describes an arc-shaped movement relative to the floor 2.

[0052] The raising system 30 also includes operating means (not shown) for controlling the raising or lowering of the seat 10. These The means of operation are preferably manual, but could alternatively be motorized. They include a lever (not visible) associated with a pumping system that forces the connecting rods to pivot in one direction or the other.

[0053] Here, the backrest 20 is mounted directly onto the seat. It can be fixed to the seat or hinged to it around a transverse axis, so as to be able to tilt. Alternatively, the backrest could be mounted on the movable rails.

[0054] Seat 1 is also equipped with a seat belt system 50.

[0055] This seat belt system could be of the two-point type (with a lap belt attached on either side of the occupant's pelvis).

[0056] Here, it will be considered rather as a three-point system. Such a system includes first of all a strap 51, one end of which is fixed to one side of the seat 1, at the level of the seat 10, and the other end of which winds into a winder fixed to the chassis of the vehicle, on the same side of the seat, at the height of the top of the backrest 20. It also includes a buckle 52 which is threaded onto the strap 51 and which has a bolt.

[0057] The seat 1 is equipped, on the other side of the seat, at the height of the seat 10, with a hooking device 100 for this safety belt buckle 52.

[0058] Two embodiments of this hanging device 100 are shown in detail in figures 2 and 5.

[0059] In these two embodiments, this hanging device 100 comprises a loop strand 110, here in a tulip shape, with a foot at the upper end of which is a clasp 112 adapted to receive said bolt to lock it.

[0060] The foot and the clasp 112 are coupled together. In other words, they are either fixed together or articulated relative to each other.

[0061] This clasp 112 incorporates a release button allowing the bolt to be released when necessary. As this clasp is well known to those skilled in the art, it will not be described in further detail here.

[0062] On the other hand, the fastening system of the clasp 112 in the vehicle can be described.

[0063] This system is provided here so that the clasp 112 can move up or down, by means of the raising or lowering of the seat 10 of the seat 1.

[0064] For this purpose, according to a particularly advantageous feature of the invention, the fastening device 100 comprises a rod 120 mounted on a rigid structure of the motor vehicle, and a system 101; 102 for mounting the clasp 112 on this rod 120, which allows the clasp 112 to slide along this rod 120 except in the event of an accident.

[0065] The structure on which the rod 120 is mounted is described as "rigid" in the sense that it is able to withstand greater stresses than the seat 10. As will be described below, the 120mm rod is designed to withstand high stresses in the event of an accident. It is therefore designed not to deform plastically in an accident and to be attached to a component that will not deform further (provided the impact does not exceed the standards for which the seat is designed).

[0066] In practice, the rod 120 is mounted either on the floor 2 of the vehicle, or on one of the fixed rails 41, or, preferably, on one of the movable rails 42.

[0067] Here, the rod 120 is mounted on one of the movable rails 42. Thus, the entire hooking device 100 moves forward or backward as the seat moves forward or backward.

[0068] The rod 120 could be fixed (without any mobility) on this movable rail 42, in which case it would preferably be chosen to be elastically flexible.

[0069] But it will be preferable to use a rigid rod 120, so that this rod 120 will preferably be articulated on the mobile rail 42, around a transverse axis called pivot axis Al.

[0070] In both embodiments illustrated in figures 2 and 5, the rod 120 is in the form of a profiled bar, that is to say a bar having a constant cross-section over a major part of its length.

[0071] This bar is for example formed from a metal strip (typically steel) with a rectangular cross-section.

[0072] This bar extends, on the side of its lower end, by an eyelet 121 which allows, via an axis, to articulate it on the movable rail 42 around the pivot axis Al.

[0073] The system 101; 102 for mounting the clasp 112 on the rod 120 is designed to allow the clasp 112 to slide along the rod 120 as the seat 10 rises or falls relative to the floor 2. However, it is designed to block this sliding when a tensile force Fl exceeding a tensile threshold Flmax is exerted on the clasp 112. This tensile threshold therefore corresponds to a limit beyond which the system activates to block the sliding of the clasp 112 along the rod 120.

[0074] This tensile force Fl corresponds to the force exerted on the clasp 112 by the occupant of seat 1 (via their seat belt 51 and buckle 52) in the event of a frontal collision. As shown in [Fig. 3], it can be modeled as a force applied to the clasp 112, along the axis of the foot, in the direction opposite to the foot.

[0075] The aforementioned Flmax traction threshold will preferably be greater than 10 N.

[0076] In both embodiments, the foot to which the clasp 112 is coupled is an integral part of the system 101 (first embodiment) or 102 (second embodiment) for mounting this clasp 112 on the stem 120.

[0077] This foot effectively forms a sheath 111 which is engaged in a sliding manner on the rod 120, so that the whole assembly is telescopic.

[0078] The sleeve 111 thus defines an internal cavity in which part of the rod 120 is housed. The faces of this internal cavity are preferably provided to be in contact with the corresponding faces of the rod 120, to guide the sliding of the latter along the axis of the rod 120.

[0079] In the two illustrated embodiments, the loop-strand 110 has a tuning fork shape, the base of which would be the clasp 112 and the two arms of which would be formed by the sheath 111.

[0080] In other words, the sleeve 111 has two parallel arms 111 A, 11 IB located on either side of two sides of the rod 120. These two arms have facing faces which are flat and which are in sliding support against two flat and opposite sides of the rod 120.

[0081] Here, the sheath 111 is open laterally, on the other two sides of the rod 120. However, alternatively, it could be closed on these two sides (and have a rectangular cross-section tube shape) or be partially closed.

[0082] Preferably, in the case where the sleeve 111 is open laterally, guides will be provided to maintain the sleeve 111 and the rod 120 on the same axis (coaxially).

[0083] In both embodiments as well, the system 101; 102 for mounting the clasp 112 on the stem 120 includes a coupling means 130; 230 of the sheath 111 to a "height-moving part" of the seat 1. This coupling means 130; 230 is intended to allow the sheath 111 to be forced up and down together with the seat 10.

[0084] The vertically movable part of the seat 1 could be the backrest or an upper end of one of the connecting rods. In practice, it is more likely the seat 10.

[0085] It should be noted here that the coupling means 130; 230 will preferably be fusible in the sense that it will be designed to fail when the tensile force Fl exceeds a breaking threshold Flrupt, preferably greater than 1000 N. This breaking threshold Flrupt will, for example, be on the order of 400 daN. In any case, it will be greater than the tensile threshold Flmax.

[0086] Thus, in the event of an accident, the coupling means 130; 230 will give way, then all the forces applied to the loop strand 110 will be able to propagate towards the rod 120, which will prevent any deformation of the seat 10.

[0087] Alternatively, the coupling means may not be fusible, or may be elastically or plastically deformable in the event of an accident.

[0088] In both embodiments, the system 101; 102 for mounting the clasp 112 on the stem 120 includes a self-locking system, formed by two Clamping means 140; 240 of the rod 120 are located on either side of this rod 120 (preferably symmetrically with respect to the axis of the rod). These clamping means 140; 240 are mounted to move relative to the sleeve 111 between a clamping position in which they block the sliding of the rod 120 relative to the sleeve 111 and a rest position in which they allow the sliding of the rod 120 relative to the sleeve 111.

[0089] Elastic return means 190 of these clamping means will then always be provided in the rest position so that, in normal operation, the loop strand can slide along the rod and that this sliding only gets blocked in the event of an accident.

[0090] At this stage, we can describe in more detail each of the two embodiments illustrated in figures 1 and 5.

[0091] In the first embodiment of the system 101 for mounting the clasp 112 on the rod 120, illustrated in figures 2 to 4, the clamping means 140 comprise two cams 141A, 141B located on either side of the rod 120 and arranged in such a way that they pinch the rod when the tensile force Fl exceeds the tensile threshold Flmax.

[0092] In the example illustrated in the figures, the sheath 111 includes a support 113 which is fixed to the free ends of its two arms 11 IA, 11 IB (opposite the clasp 112), and on which the clamping means 140 are mounted.

[0093] Here, this support 113 is formed of two plates 114, 115 which are fixed to the ends of the arms, in parallel, bearing respectively against their inner and outer faces. These two plates 114, 115 thus delimit between them a space in which the two cams 141A, 141B are housed.

[0094] In [Fig. 3], a first of the two clamping means 140 is shown, viewed from the side and from above. This first clamping means 140 comprises, in addition to the cam 141A, a pin 143A and a latch 142A.

[0095] The pin 143A is designed to assemble the cam to the latch and to allow them to be mounted on the support 113 in a rotationally movable manner. In practice, this pin 143A is preferably cylindrical of revolution about a transverse pivot axis A3. Here, it is engaged through two coaxial openings provided respectively in the two plates 114, 115. This pin has a head that allows it to be locked, in one direction, through the coaxial openings.

[0096] The cam 141A is formed by a plate with a non-circular contour around the pivot axis A3, located in a plane orthogonal to this axis. In practice, the radius of this plate around the pivot axis A3 varies.

[0097] The latch 142A forms a finger. It extends orthogonally with respect to the pivot axis A3, at a distance from the cam 141A.

[0098] It should be noted that the other of the two clamping means 140 is substantially identical to the first clamping means 140 described above and illustrated in [Fig.3]. As shown in [Fig.4], its cam 141B and latch 142B extend symmetrically with respect to those of the first clamping means (on either side of the axis of the rod 120).

[0099] One difference between the two clamping means 140, visible in the cross-sectional view of [Fig.2], is that the distance between the cam and the latch is greater for one of the clamping means 140 than for the other (the difference in distances being at least equal to the thickness of one of the latches, measured along the pivot axis A3).

[0100] As shown in this cross-sectional view of [Fig.2], the two cams 141A, 141B are housed in the space delimited between the two plates 114, 115. In contrast, the two latches 142A, 142B are located outside this space, on the inner side (seating side).

[0101] Due to the aforementioned difference in distances, if the two cams 141A, 141B extend in the same average plane, the same is not true for the two latches 142A, 142B which are offset and can therefore cross without colliding when the two clamping means 140 pivot around their pivot axes A3.

[0102] For the assembly of the clamping means 140, it can be provided, for example, that the pins 143A, 143B and the catches 142A, 142B are formed as a single piece. They are then installed first on one of the two plates 114. The cams 141A, 141B are then press-fitted onto the pins 143A, 143B before the other of the plates 115 is attached to the assembly. The two plates 114, 115 can then be bolted to the ends of the sleeve arms 111.

[0103] These clamping means 140 are mounted on the support 113 so as to be free to rotate around the pivot axes A3.

[0104] They are thus mobile in rotation between a rest position, where the cams 141A, 14IB extend either at a distance from the rod 120, or in sliding contact against the rod 120, and a clamping position where they extend in tight contact against the rod 120.

[0105] The term "sliding support" or "sliding contact" means that the cams 141A, 141B are in contact with the rod 120 but do not prevent it from sliding in the sleeve along the axis of the rod 120 when the user adjusts the height of his seat.

[0106] On the other hand, "tight support" means that the cams 141 A, 141 B are in contact with the rod 120 and prevent it from sliding in the sleeve 111 regardless of the tensile force Fl, provided that it is greater than said threshold Flmax (and that it is less than a limit beyond which one of the components of the fastening device would deform plastically). It is therefore clear that the threshold Flmax corresponds to the resistance threshold of the elastic return means 190, that is to say, the limit from which the forces are such that the elastic return means 190 deform sufficiently to block the translation.

[0107] In practice, the resting and jamming positions can therefore be very close to each other.

[0108] In this first embodiment, the elastic return means 190 of these clamping means 140 in the rest position could be in various forms. Here, as shown in [Fig. 2], a torsion spring 190A, 190B is mounted on each pin 143A, 143B, such that one of its ends is fixed to this pin and the other rests on the support 113.

[0109] A system for operating the clamping means 140 is then provided, allowing the cams 141A, 141B to be rotated from their rest position to their clamping position under the effect of the tensile force Fl, provided that this force is greater than said threshold Flmax.

[0110] In practice, this maneuvering system is formed by the coupling means 130 of the sleeve 111 to the seat 10.

[0111] This coupling means 130 includes a finger 131 which is fixed to the seat 10 and which is engaged in an opening 114 provided in the sleeve 111.

[0112] This finger 131 could take various forms. Here it takes the form of a cylindrical rod of revolution about a transverse axis.

[0113] The shape of the opening 114 is such that the finger 131 can slide in it along the axis of the rod 120. In practice, this opening 114 is therefore oblong in shape.

[0114] It has a length of approximately twice the diameter of the finger 131 and must be sufficient so as not to impede the push on the latches 142.

[0115] At rest, the latches 142A, 142B extend under the finger 131 (opposite the clasp), at a distance from it, or in light contact with it.

[0116] Thus, as illustrated in [Fig.4], when the seat rises, the finger 131 moves up into the opening and then, when it comes to rest against the upper end of the latter, it forces the sleeve 111 and the clasp 112 to move up along the rod 120. Thanks to the springs 190A, 190B, the cams 141A, 141B do not prevent this movement.

[0117] Conversely, when the seat descends, the finger 131 descends into the opening and then, when it comes to rest against the latches 142A, 142B, it forces the sleeve to descend along the rod 120. Thanks to the springs 190A, 190B, the latches do not pivot so much that the cams 141A, 141B do not prevent this movement.

[0118] Conversely, in the event of an accident, if the tensile force Fl exceeds the maximum tensile force Flmax, the finger 131, linked to the seat 30 which nevertheless resists, descends, relatively, into the opening and then, when it reaches the stop against the latches 142A, 142B, it forces these latches (and therefore the clamping means 140) to pivot around the pivot axes A3. The springs 190A, 190B are no longer sufficient to hold the latches in the rest position. This pivoting movement allows the cams 141A, 141B tighten on the rod 120, which blocks any movement of the sleeve 111 along the rod 120.

[0119] It will be noted that the forces exerted by the cams 141A, 141B on the rod 120 will then be all the greater as the tensile force Fl is significant, which will ensure an effective locking of the rod 120 between the support 130 and the cam 140.

[0120] In practice, the pinching force generated orthogonally to the axis of the rod 120 is greater than 3 times the tensile force Fl exerted along the axis of the rod 120 (it depends on the ratio of the two lever arms as follows: - the lever arm between axis A3 and axis finger 130, on - the lever arm between axis A3 and the point of contact of cam 141A on rod 120).

[0121] In this jammed position, the tensile force Fl exerted by the bolt on the clasp 112 will be fully transmitted to the rod 120, and therefore to the fixed rail 42, via the cams 140.

[0122] It should be noted in this first embodiment, the fuse may be formed by the finger 131, which will give way in the event of an accident so as to decouple the sleeve 111 from the seat 10.

[0123] In the example illustrated in the figures, both the sides of the rod 120 and the contour of the cams 141A, 141B are smooth.

[0124] However, alternatively, these sides and contour could be designed to have raised features, such as micro-notches. In this way, the locking of the sleeve 111 along the rod 120 in the event of an accident will be more effective, particularly if a lubricant has leaked along the rod.

[0125] In the second embodiment of the system 102 for mounting the clasp 112 on the rod 120, illustrated in figures 5 to 7, the coupling means 230 of the sleeve 111 to the seat 10 comprise a ring 232 which extends around the sleeve 111, and the clamping means 240 comprise two pucks 240A, 240B distributed on either side of the rod 120, each sandwiched between the ring 232 and the sleeve 111, and more precisely between a face of the ring and a face of the sleeve which are shaped in such a way that they force the two arms 11 IA, 11 IB of the sleeve 111 to come and pinch the rod 120 when the tensile force Fl exceeds the threshold induced by the resistance of the seat.

[0126] In practice, the sheath 111 is this time without support: the ends of its two arms are free and these two arms 11 IA, 11 IB are separated from each other (at rest) in such a way that they can bend towards each other in order to pinch the rod 120.

[0127] In this second embodiment, the coupling means 230 comprises a finger 231 which is fixed to the seat and which carries at its opposite end the ring 232.

[0128] This ring 232 preferably has an annular shape, but alternatively, it could be split, or even have a U shape. In any case, it forms at least one clamp that extends on either side of the two arms of the sheath 111.

[0129] Here, the ring 232 has a rectangular shape. As shown in [Fig.6], it has an inner edge which has four faces, including two main faces 239A, 239B located opposite the distal faces 119A, 119B of the two arms 111A, 11IB (those furthest from the stem 120).

[0130] The two pucks 240A, 240B are then respectively sandwiched between one of the two main faces 239A and the opposite distal face 119A, and between the other of the two main faces 239B and the opposite distal face 19B.

[0131] As shown by the arrows on this [Fig.6], these pucks are therefore located at the level where shear forces occur in the event of an accident, when the sleeve is pulled upwards and the ring is held in a fixed position.

[0132] In order for these pucks 240A, 240B to then force the two arms 11 IA, 11 IB of the sleeve 111 to come together and press tightly against the rod 120 in case of an accident, it is provided that the main faces 239A, 239B of the ring 232 and / or the distal faces 119A, 119B of the two arms 11 IA, 11 IB are inclined with respect to the axis A2 of the rod 120.

[0133] Typically, it could be expected that the main faces 239A, 239B of the ring 232 are sloped with respect to the axis A2 of the rod 120 and that the distal faces 119A, 119B of the two arms 11 IA, 11 IB extend parallel to the axis A2 of the rod 120.

[0134] Conversely, it could be foreseen that the main faces 239A, 239B of the ring 232 extend parallel to the axis A2 of the rod 120 and that the distal faces 119A, 119B of the two arms 11 IA, 11 IB are sloped with respect to the axis A2 of the rod 120.

[0135] Here, both the main faces 239A, 239B of the ring 232 and the distal faces 119A, 119B of the two arms 11 IA, 11 IB are sloped with respect to the axis A2 of the stem 120.

[0136] The idea is that when the sheath 111 slides upwards relative to the ring 232, these slopes force the two arms 11 IA, 11 IB of the sheath to move closer together.

[0137] Here, the main faces 239A, 239B of the ring 232 and the distal faces 119A, 119B of the two arms 111A, 111B each have a concave curved portion for receiving and retaining one of the pucks 240A, 240B. This portion, called the cradle, has an arcuate cross-section.

[0138] Each puck has a spherical ball shape or a cylindrical rod of revolution, with a diameter equal to the diameter of the cradle.

[0139] It is thus understood that in the rest position, each puck 240A, 240B is housed in two cradles, which keeps the sleeve 111 in this position relative to the ring 232.

[0140] It is therefore the elasticity of the arms 11 IA, 11 IB, which tend to flex in opposite directions, that returns the pucks to this rest position. The aforementioned return means are thus constituted, in this mode, by the arms themselves.

[0141] Each cradle extends onto another part (called a ramp) that slopes relative to the axis A2 of the rod 120. On the sleeve, the cradle is located closer to the clasp 112 than the slope. The opposite is true on the ring 230.

[0142] As a result, the traction effort Fl tends to make the pallets come out of their cradles so that they roll on the ramps and thus force the arms 111 A, 11 IB to come closer together.

[0143] At rest, the proximal faces of the arms (those facing the rod 120) then extend either to a distance j 1 from the rod 120 ([Fig.6]), or in sliding contact against the rod 120.

[0144] Thus, when the seat rises, the ring 232 rises and forces the sleeve 111 to rise, thanks to the pucks which are compressed between the cradles.

[0145] When the seat 10 and the ring 232 descend together, the elasticity of the arms 111 A, 11 IB forces the pucks 240A, 240B to remain at the bottom of the cradles, so that the sleeve also descends.

[0146] In contrast, the 240A, 240B pucks are adapted to be extracted from the cradles when the tensile force Fl exceeds the Flmax tensile threshold induced by the resistance of the base. This threshold therefore also depends, in particular, on the elasticity of the arms 11 IA, 11 IB.

[0147] In other words, in the event of an accident, the ring 232 is locked in a fixed position by the seat and the sleeve 111 is pulled upwards by the loop 52, along the axis A2 of the rod 120. The shear force produced is such that the pucks 240A, 240B will come out of their cradles and slide against the ramps, thus forcing the arms 111 A, 11 IB to bend towards each other until they come into tight contact with the rod 120.

[0148] As a result, the sheath 111 becomes stuck on the rod 120.

[0149] It should be noted here that the two arms 11 IA, 11 IB have, on the side of their extremities free, jaws 115A, 115B protruding from their proximal faces, which are adapted to come into contact with the stem.

[0150] The tensile force Fl along the axis A2 of the rod then generates, via the ramps and the pucks 240A, 240B, a pinching force orthogonal to the axis A2 which is greater than 25 times the intensity of the tensile force (with ramps inclined at an angle al of 2° with respect to the axis A2).

[0151] In the example illustrated in the figures, both the sides of the rod 120 and the jaws 115A, 115B are smooth.

[0152] But here again, as an alternative, it could be envisaged that these sides and jaws have raised features forming, for example, a micro-notch. In this way, the locking of the sheath 111 along the rod 120 in the event of an accident will be more effective, particularly if a lubricant has leaked along the rod.

[0153] It should be noted in this second mode that the fuse can be formed by the finger 231.

[0154] The present invention is in no way limited to the embodiments described and referred to presented, but a person skilled in the art will be able to make any variation that conforms to the invention.

[0155] Typically, the rod could have a circular cross-section, in which case the edges of the cams (variant of the first mode) or the jaws (variant of the second mode) would be hollowed out to fit the shape of the rod.

[0156] In the illustrated embodiments, two symmetrically movable clamping means are provided. Alternatively, one clamping means could be fixed and the other movable. Typically, in the first embodiment, a single cam could be provided on one side of the rod, adapted in case of an accident to force the rod against a fixed stop so as to lock it against this stop (this fixed stop thus forming the other clamping means).

Claims

Demands

1. A fastening device (100) for a motor vehicle seat belt buckle (52), comprising: - a clasp (112) adapted to receive said seat belt buckle (52), - a rod (120) adapted to be mounted on a rigid structure (42) of the motor vehicle, and - a sliding movable mounting system (101; 102) for the clasp (112) along said rod (120), adapted to block said sliding when a tensile force (Fl) exceeding a threshold (Flmax) is exerted on the clasp (112), characterized in that the sliding movable mounting system (101; 102) comprises: - a sleeve (111) coupled to the clasp (112), which houses at least part of said rod (120) and is adapted to slide along said rod (120), - a coupling means (130; 230) of the sheath (111) to a height-moving part of a seat (1) of the motor vehicle, - two clamping means (140;240) of the rod (120) which are located on either side of the rod (120) and of which at least one is mounted movable relative to the sleeve (111) between a clamping position in which they block the sliding of the rod (120) relative to the sleeve (111) and a rest position in which they release the sliding of the rod (120) relative to the sleeve (111), and - elastic return means (190) of the clamping means (140; 240) in the rest position.;

2. A latching device (100) according to claim 1, wherein the coupling means (130; 230) is fusible and is adapted to yield when said tensile force (Fl) exceeds a breaking threshold (Flrupt).

3. Attachment device (100) according to any one of claims 1 and 2, wherein the sheath (111) has two arms (111 A, 11 IB) which extend on either side of two sides of the rod (120) and the sheath (111) is open on two other sides of the rod (120).

4. A fastening device (100) according to any one of claims 1 to 3, wherein the clamping means (240) respectively comprise two pucks (240A, 240B), each of which is sandwiched between two faces (119A, 119B, 239A, 239B) respectively carried by the sleeve (111) and by the coupling means (230), the two faces (119A, 119B, 239A, 239B) having shapes such that, in the rest position, the sleeve (111) extends either at a distance from the rod (120), or in sliding contact against the rod (120), and that, in the jamming position, the pucks (240A, 240B) block the sleeve (111) in tight contact against the rod (120).

5. A hooking device (100) according to claim 4, wherein at least one of said two faces (119A, 119B, 239A, 239B) forms a cradle for holding the puck (240A, 240B) in the rest position, which extends into a ramp inclined relative to the rod (120), and in which the pucks (240A, 240B) are shaped to be extracted from the cradles and slide against the inclined ramps when the tensile force (Fl) is greater than said threshold (Flmax).

6. A hooking device (100) according to any one of claims 1 to 3, wherein the clamping means (140) comprise two cams (141A, 141B) movable in rotation between the rest position, where they extend either at a distance from the rod (120), or in sliding contact against the rod (120), and the clamping position where they extend in tight contact against the rod (120).

7. A latching device (100) according to claim 6, wherein the coupling means (130) has a finger (131) engaged in an opening (114) which is provided in the sleeve (111) and whose shape allows the coupling means (130) to slide relative to the sleeve (111), and wherein the cams (141A, 141B) are equipped with latches (142A, 142B) which are adapted to bear against the coupling means (130) when the tensile force (Fl) is greater than said threshold (Flmax) to force the cams (141A, 141B) to pivot into the jamming position.

8. A motor vehicle seat (1) adapted to be mounted on a floor (2) of the motor vehicle, comprising: - a seat (10), - a backrest (20), - a riser system (30) allowing the height of the seat (10) to be varied relative to the floor (2), characterized in that it comprises a fastening device (100) according to any one of claims 1 to 7.

9. Seat according to claim 8, comprising a sliding system (40) which includes two fixed rails (41) adapted to be fixed to the floor (2), two movable rails (42) mounted to slide on the two fixed rails, a sliding blocking device for the movable rails (42) relative to the fixed rails (41), and means for deactivating the blocking means, the rod (200) being mounted on one of the movable rails (42).

10. Motor vehicle comprising a floor (2) and a seat (1) conforming to one of claims 8 and 9.

Images