Seat belt buckle attachment device

Abstract

The invention relates to a fastening device (100) for a seat belt buckle (52), comprising: - a loop strand (110) comprising a clasp (112) adapted to receive said buckle, - a rigid rod (120), and - a sliding movable mounting system (101) of the clasp (112) along said rod, which is adapted to block said sliding when a tensile force (F1) greater than a threshold is exerted on the clasp. According to the invention, the sliding movable mounting system comprises: - a sheath (111) coupled to the clasp and which houses the rod, - a means for coupling the sheath to a seat base, - two clamping means (140) located on either side of the rod and movable between a position for wedging the rod and a rest position in which the rod can slide relative to the sheath, and - means for returning the clamping means to the rest position. Figure for 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 a fastening device for a seat 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 mobile mounting system for sliding the clasp along said rod, which is adapted to block said sliding when a tensile force greater than 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 front-to-back sliding mobility and up-and-down movement mobility.

[0005] Such a seat generally comprises a seat, a slide system formed of two parallel fixed rails which are fixed to the floor, two movable rails which are capable of sliding along the two aforementioned rails, and raising means which connect the seat to the movable rails and which make it possible to adjust the height of the seat relative to the floor.

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

[0007] Such a seat is equipped with a seat belt buckle strand comprising a foot and, at its upper end, a clasp capable of receiving and locking the bolt of a seat belt buckle.

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

[0009] The disadvantage then is that the clasp does not follow the height movement of the seat structure, which is detrimental to the overall ergonomics of the vehicle. Indeed, when the seat is in the high position, the clasp is located too low to be easily accessible. In addition, when the seat occupant has fastened his seat belt and wants to raise the seat, the latter tightens around his pelvis and prevents him from raising the seat.

[0010] In order to address this issue, document US20140265503 discloses a seat whose loop-end comprises a leg and a clasp, but whose lower end of the leg is coupled to the seat structure so as to follow the vertical movement of the latter. More precisely, this lower end is housed in a housing fixed to the seat. This same housing is crossed by a rigid rod which extends parallel to the leg, and whose lower end is articulated on one of the movable rails. A spring is sandwiched between the rigid rod and the leg to keep them apart from each other, in particular when the seat and the loop-end rise, and the housing slides along the rigid rod. On the other hand, when a tensile force greater than a threshold is exerted on the loop-end (typically in the event of an accident), the spring is crushed so that the foot comes to bear against a toothed portion of the movable rod.This toothed portion then makes it possible to block the sliding of the rigid rod in the housing, so that the tensile force is transmitted directly from the clasp to the movable 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 is not done in a satisfactory manner.

[0012] Furthermore, the rigid rod has the disadvantage of protruding above the seat when the latter occupies 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 overcome the aforementioned drawbacks of the state of the 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 a hooking device as defined in the introduction, in which the system for sliding the loop-strand along the rod comprises: - a sheath which is coupled to the clasp, which at least partially houses said rod and which is adapted to slide along said rod, - a means of coupling the sheath to a movable part in height of a seat of the motor vehicle, - two means for clamping the rod which are located on either side of the rod and at least one of which is mounted to move relative to the sheath between a position of jamming in which the two clamping means block the sliding of the rod relative to the sheath and a rest position in which they release the sliding of the rod relative to the sheath, and - elastic return means of the clamping means to the rest position.

[0015] Thus, thanks to the invention, the foot of the loop-strand forms a sheath on the rod, so that the latter is neither visible nor bothersome for the occupant of the seat. To do this, the system for mounting the clasp sliding on the rod comprises, in addition to this sheath, self-locking means making it possible to block the sliding of the sheath on the rod together in the event of an accident.

[0016] It can be noted that in such a device, the angular movement of the sheath is very small, so that it is possible to integrate the entire device (with the exception of the clasp) inside the seat covering (or even within the seat frame). This device is thus compact, aesthetic, 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 electric wire connecting this sensor, the latter can then also be hidden within the seat.

[0018] Other advantageous and non-limiting characteristics of the attachment device according to the invention, taken individually or in all technically possible combinations, are the following: - the coupling means is fusible and is adapted to yield when said tensile force exceeds a breaking threshold; - the sheath has two arms which extend on either side of two sides of the rod and the sheath is open on two other sides of the rod; - the clamping means comprise two discs sandwiched between two faces carried respectively by the sheath and by the coupling means, the two faces having shapes such that, in the rest position, the sheath extends either at a distance from the rod, or in sliding contact against the rod, and that, in the wedging position, the discs block the sheath in tight contact against the rod; - at least one of said two faces forms a cradle for holding the puck in the rest position, which is extended by a ramp inclined relative to the rod; - the pallets are shaped to be extracted from the cradles and slide against the inclined ramps when the tractive force is greater than said threshold; - the clamping means comprise two cams which can rotate between the rest position, where they extend either at a distance from the rod or in sliding contact against the rod, and the wedging position where they extend in tight contact against the rod; - the coupling means comprises a finger engaged in an opening which is provided in the sheath and the shape of which allows the coupling means to slide relative to the sheath; - the cams are equipped with latches which are adapted to bear against the coupling means when the tensile force is greater than said threshold to force the cams to pivot into the wedging position;

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

[0020] Preferably, the seat comprises a slide system which comprises two fixed rails adapted to be fixed to the floor, two movable rails mounted to slide on the two fixed rails, a member for blocking the sliding of the movable rails relative to the fixed rails, and means for deactivating the blocking means, the rod being mounted on one of the movable rails.

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

[0022] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0023] The description which follows with reference to the appended drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0024] In the attached drawings:

[0025] [Fig.l] 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.l], seen from the side and in section along a plane AA;

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

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

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

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

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

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

[0033] In [Fig. 1], there is shown a seat intended to be installed in the passenger compartment of a such motor vehicle and to be fixed to the chassis of this motor vehicle, and more precisely on the floor 2 of this motor vehicle.

[0034] In the remainder of the 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 this element which is located on the side of the hood of the vehicle and the rear part designating the part of this element which is located on the opposite side.

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

[0036] The adjective "longitudinal" will 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" will apply to a direction or axis oriented orthogonally to the longitudinal axes and horizontally 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 the seat and away from it.

[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 hereinafter designate a coupling by simple pivot connection. But as a variant, it could also designate a ball joint.

[0040] A joint can be obtained in various ways. It can, for example, be operated by a screw which passes through an opening provided in a first 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.l], the seat 1 conventionally comprises a seat 10 and a backrest 20, each comprising a frame and a trim 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 comprise two metal lateral sides, rigidly connected together by metal connecting elements. Of course, as a variant, these frames could be presented differently, for example in the form of plastic shells.

[0043] In the context of the invention, the seat 10 is intended to be mounted mobile in height on the floor 2, between low positions (shown in solid lines) and high positions (shown in dotted lines). The seat 1 has a raising system 30 for this purpose.

[0044] Preferably, the seat 10 is also designed to be mounted so as to be movable back and forth on the floor 2. The seat 1 comprises a slide system 40 for this purpose.

[0045] These raising systems 30 and slide 40 are well known. They could come in very varied forms. Here, we can briefly describe, by way of example, one embodiment of these systems.

[0046] In this embodiment, the slide system 40 comprises two fixed rails 41 which extend 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 equipped with screws for fixing them 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 relative to the fixed rails 41 is a sliding movement along a longitudinal axis.

[0048] The slide system 40 also comprises 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 makes it possible, when the occupant of the seat wishes to move his seat 1 forward or backward, to move the notches of this accessory away from those of the fixed rail to free up the sliding mobility of the seat 10.

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

[0051] In the example illustrated, the raising system 30, for its part, comprises two pairs of connecting rods 31, 32. Each connecting rod 31, 32 is articulated, on one side, on one of the movable rails 42 and, on the other, on one of the lateral flanks of the frame of the seat 10, around a transverse axis. The two connecting rods 31, 32 of each pair of connecting rods extend substantially parallel to each other, between one of the movable rails 42 and one of the lateral flanks, so as to form with the latter a sort of deformable parallelogram. Thus the seat 10 can move relative to the floor 2 following a so-called rotary translation movement, in which the seat maintains a substantially constant inclination and describes an arc-of-circle movement relative to the floor 2.

[0052] The raising system 30 also comprises operating means (not shown) making it possible to control the raising or lowering of the seat 10. These The operating means are preferably manual, but they could alternatively be motorized. Here they include a lever (not visible) associated with a pumping system allowing the connecting rods to be forced to pivot in one direction or the other.

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

[0054] The 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 strap attached on either side of the seat occupant's pelvis).

[0056] Here, it will be considered rather that it is a three-point system. Such a system firstly comprises a strap 51, one end of which is fixed on a first side of the seat 1, at the level of the seat 10, and the other end of which is wound in a reel fixed to the chassis of the vehicle, on this same side of the seat, at the height of the top of the backrest 20. It also comprises a loop 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 seat belt buckle 52.

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

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

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

[0061] This clasp 112 incorporates an unlocking button allowing the bolt to be released if necessary. This clasp being well known to those skilled in the art, it will not be described in more detail here.

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

[0063] This system is provided here so that the clasp 112 can rise or fall, in response to the rise or fall of the seat 10 of the seat 1.

[0064] For this, according to a particularly advantageous characteristic of the invention, the attachment 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 clearly described below, the rod 120 is designed to be subjected to high stresses in the event of an accident. It is therefore designed not to deform plastically in the event of an accident and to be fixed to an element which does not deform further (provided that 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 mobile rails 42.

[0067] Here, the rod 120 is mounted on one of the movable rails 42. Thus, the entire attachment 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 movable rail 42, around a transverse axis called pivot axis A1.

[0070] In the two 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 section over a major part of its length.

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

[0072] This bar is extended, 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 A1.

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

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

[0075] The aforementioned traction threshold Flmax 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 mode) or 102 (second mode) for mounting this clasp 112 on the rod 120.

[0077] This foot in fact forms a sheath 111 which is slidably engaged on the rod 120, so that the assembly is telescopic.

[0078] The sheath 111 thus delimits an interior cavity in which a part of the rod 120 is housed. The faces of this interior cavity are preferably designed 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 embodiments illustrated, the loop-strand 110 has a tuning fork shape whose base would be the clasp 112 and whose two arms would be formed by the sheath 111.

[0080] In other words, the sheath 111 comprises two parallel arms 111A, 111B 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, as a variant, it could be closed on these two sides (and have the shape of a tube with a rectangular section) or be partially closed.

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

[0083] In both embodiments also, the system 101; 102 for mounting the clasp 112 on the rod 120 comprises a coupling means 130; 230 of the sheath 111 to a “height-moving part” of the seat 1. This coupling means 130; 230 is provided to allow the sheath 111 to be forced to rise and fall together with the seat 10.

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

[0085] It will already be noted here that the coupling means 130; 230 will preferably be fusible in the sense that it will be designed to yield when the tensile force Fl exceeds a breaking threshold Flrupt, preferably greater than 1000 N. This breaking threshold Flrupt will for example be of the order of 400 daN. It will in any case 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 of 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 also, the system 101; 102 for mounting the clasp 112 on the rod 120 comprises a self-locking system, formed by two clamping means 140; 240 of the rod 120 which 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 sheath 111 between a wedging position in which they block the sliding of the rod 120 relative to the sheath 111 and a rest position in which they release the sliding of the rod 120 relative to the sheath 111.

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

[0090] At this stage, each of the two embodiments illustrated in Figures 1 and 5 can be described in more detail.

[0091] In the first embodiment of the system 101 for mounting the clasp 112 on the rod 120, illustrated in FIGS. 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 comprises a support 113 which is fixed to the free ends of its two arms 11 1A, 11 1B (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 internal and external 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, seen 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 provided for assembling the cam to the latch and for allowing them to be mounted on the support 113 in a movable manner in rotation. In practice, this pin 143A is preferably cylindrical of revolution around 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 which allows it to be blocked, 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 to the pivot axis A3, at a distance from the cam 141A.

[0098] It will 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] A difference between the two clamping means 140, visible in the 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 sectional view of [Fig.2], the two cams 141A, 141B are housed in the space delimited between the two plates 114, 115. On the other hand, the two latches 142A, 142B are located outside this space, on the internal side (seat 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 is possible, for example, to provide that the pins 143A, 143B and latches 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 force-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 arms of the sheath 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 movable 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 wedging position where they extend in tight support against the rod 120.

[0105] By “sliding support” or “sliding contact” is meant that the cams 141A, 141B are in contact with the rod 120 but do not prevent it from sliding in the sheath 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 sheath 111 whatever 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 attachment 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 to the limit from which the forces are such that the elastic return means 190 deform sufficiently to block the translation.

[0107] In practice, the rest and wedging 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, so 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, making it possible to pivot the cams 141A, 141B from their rest position to their wedging position under the effect of the tensile force Fl, provided that this force is greater than said threshold Flmax.

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

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

[0112] This finger 131 could be presented in various forms. Here it is presented in the form of a cylindrical rod of revolution around a transverse axis.

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

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

[0115] At rest, the latches 142A, 142B extend under the finger 131 (opposite the clasp), at a distance from the latter, or pressing lightly against the latter.

[0116] Thus, as illustrated in [Fig.4], when the seat rises, the finger 131 rises in the opening then, when it comes into abutment against the upper end of the latter, it forces the sheath 111 and the clasp 112 to rise 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 then, when it comes into abutment against the catches 142A, 142B, it forces the sheath to descend along the rod 120. Thanks to the springs 190A, 190B, the catches do not pivot so that the cams 141A, 141B do not prevent this movement.

[0118] On the other hand, in the event of an accident, if the traction force Fl exceeds the traction threshold Flmax, the finger 131, linked to the seat 30 which nevertheless resists, descends, relatively, into the opening then, when it comes into abutment 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 in fact no longer sufficient to hold the latches in the rest position. This pivoting movement allows the cams 141A, 141B to tighten on the rod 120, which blocks any movement of the sheath 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 important, which will ensure effective blocking 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 the axis A3 and the axis of the finger 130, on - the lever arm between the axis A3 and the contact point of the cam 141A on the rod 120).

[0121] In this wedging 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 will 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 sheath 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, as a variant, it may be envisaged that these sides and contours have reliefs forming, for example, a micro-notch. In this way, the blocking of the sheath 111 along the rod 120 in the event of an accident will be more effective, in particular if a lubricating product has flowed along the rod.

[0125] In the second embodiment of the system 102 for mounting the clasp 112 on the rod 120, illustrated in FIGS. 5 to 7, the coupling means 230 of the sheath 111 to the seat 10 comprise a ring 232 which extends around the sheath 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 sheath 111, and more precisely between a face of the ring and a face of the sheath which are shaped in such a way that they force the two arms 11 1A, 11 1B of the sheath 111 to pinch the rod 120 when the tensile force F1 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 1A, 11 1B are spaced apart from each other (at rest) in such a way that they can flex 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 as a variant, it could be split, or even have a U shape. In any case, it forms at least one clamp which 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, 111B (those furthest from the rod 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 119B.

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

[0132] So that these pucks 240A, 240B then force the two arms 11 IA, 11 IB of the sheath 111 to come together and come into tight contact with the rod 120 in the event 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 sloping relative to the axis A2 of the rod 120.

[0133] Typically, it could be provided that the main faces 239A, 239B of the ring 232 are sloping relative to the axis A2 of the rod 120 and that the distal faces 119A, 119B of the two arms 11 1A, 11 1B extend parallel to the axis A2 of the rod 120.

[0134] Conversely, it could be provided 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 1A, 11 1B are sloping relative 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 1A, 11 1B are sloping relative to the axis A2 of the rod 120.

[0136] The idea is that when the sheath 111 slides upwards relative to the ring 232, these slopes force the two arms 11 1A, 11 1B of the sheath to move closer to each other.

[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 one of the pucks 240A, 240B and holding it there. This portion, called a cradle, here has an arcuate section.

[0138] Each puck has the shape of a spherical ball 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 maintains the sheath 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, which returns the pucks to this rest position. The aforementioned return means are therefore constituted, in this mode, by the arms themselves.

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

[0142] As a result, the traction force F1 tends to cause the pucks to come out of their cradles so that they roll on the ramps and thus force the arms 111 A, 111 B to come closer together.

[0143] At rest, the proximal faces of the arms (those facing the rod 120) then extend either at 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 sheath 111 to rise, thanks to the pucks which are compressed between the cradles.

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

[0146] On the other hand, the pucks 240A, 240B are adapted to be extracted from the cradles when the traction force Fl is greater than the traction threshold Flmax induced by the resistance of the seat. 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 blocked in a fixed position by the seat and the sheath 111 is pulled upwards by the loop 52, along the axis A2 of the rod 120. The shearing force produced is such that the pucks 240A, 240B will come out of their cradles and slide against the ramps, thus forcing the arms 111A, 111B to flex towards each other until they come into tight contact with the rod 120.

[0148] As a result, the sheath 111 is blocked on the rod 120.

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

[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° relative 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 a variant, it could be envisaged that these sides and jaws have reliefs forming for example a micro-notch. In this way, the blocking of the sheath 111 along the rod 120 in the event of an accident will be more effective, in particular if a lubricating product has flowed along the rod.

[0153] It will 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 re presented, but those skilled in the art will be able to make any variation in accordance with the invention.

[0155] Typically, the rod could have a circular 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 match the shape of the rod.

[0156] In the illustrated embodiments, two symmetrically movable clamping means are provided. However, as a variant, one of the 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, suitable in the event of an accident for forcing the rod to bear against a fixed stop so as to block it against this stop (this fixed stop thus forming the other clamping means).

Claims

Claims

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

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

3. Hanging device (100) according to one of claims 1 and 2, in which the sheath (111) comprises two arms (111 A, 111 B) 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. Attachment device (100) according to one of claims 1 to 3, in which the clamping means (240) respectively comprise two pucks (240A, 240B), which are each located sandwiched between two faces (119A, 119B, 239A, 239B) carried respectively by the sheath (111) and by the coupling means (230), the two faces (119A, 119B, 239A, 239B) having shapes such that, in the rest position, the sheath (111) extends either at a distance from the rod (120), or in sliding contact against the rod (120), and that, in the wedging position, the pucks (240A, 240B) block the sheath (111) in tight contact against the rod (120).

5. Attachment device (100) according to claim 4, in which 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 is extended by 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. Attachment device (100) according to one of claims 1 to 3, in which 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 wedging position where they extend in tight support against the rod (120).

7. Attachment device (100) according to claim 6, in which the coupling means (130) comprises a finger (131) engaged in an opening (114) which is provided in the sheath (111) and whose shape allows sliding of the coupling means (130) relative to the sheath (111), and in which 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 wedging position.

8. Motor vehicle seat (1) adapted to be mounted on a floor (2) of the motor vehicle, comprising: - a seat (10), - a backrest (20), - a raising system (30) making it possible to vary the height of the seat (10) relative to the floor (2), characterized in that it comprises a hooking device (100) according to one of claims 1 to 7.

9. Seat according to claim 8, comprising a slide system (40) which comprises 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 member for blocking the sliding of 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) according to one of claims 8 and 9.

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