Tiltable seat frame

Abstract

The invention relates to a seat frame comprising: - a backrest frame, - a seat pan frame, and - means for mounting the backrest frame on the seat pan frame. According to the invention, said mounting means comprise, on each side of the seat frame, two attachment systems, a first of the attachment systems (32) being adapted to form a hinge while the other attachment system (33) comprises a screw (330) which, in a fully screwed state, prevents any rotation of the backrest frame relative to the seat pan frame about said hinge and which is fusible.

Description

[0001] TITLE OF THE INVENTION: A TILTING SEAT MATU E

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates generally to the field of seats.

[0004] It relates more particularly to a seat frame comprising:

[0005] - a backrest frame,

[0006] - a seat frame, and

[0007] - means for assembling the backrest frame with the seat frame, which comprise, on each side of the seat frame, two fixing systems such as bolts.

[0008] The invention also relates to a seat comprising such a frame, and a vehicle equipped with such a seat.

[0009] STATE OF THE ART

[0010] Currently, driver's seats installed in motor vehicles allow drivers to adjust their driving positions. Passenger seats in these vehicles may also be equipped with means for passengers to adjust their positions.

[0011] These seats are of two types, namely manually operated and electrically operated. Typically, a seat is known comprising a seat frame and a backrest frame hinged to each other by means of two "gussets" located on either side of the seat. Each gusset is in the form of a metal part which is fixed to the seat frame and which has an opening allowing the backrest to be hinged so that it can tilt forward or backward.

[0012] These frames are designed so as not to deform excessively in the event of an accident.

[0013] However, it can happen that during an impact, the vehicle chassis or the seat frame deforms despite everything and it is difficult to free the occupants of the vehicle.

[0014] In this case, the current solution is to cut the vehicle's pillars to remove the roof to gain easier access to the victims. Unfortunately, this solution requires the use of powerful cutting pliers, which emergency services must be equipped with. Even if they did have them, this operation is time-consuming to carry out, which can have serious consequences for the victims.

[0015] PRESENTATION OF THE INVENTION

[0016] It is in this context that the plaintiff sought new solutions to facilitate the extrication of victims. One idea is to tilt the backrest backwards, horizontally, so that they can be extracted through the luggage compartment.

[0017] For this purpose, the aforementioned mobility of tilting the backrest relative to the seat could be used.

[0018] But whether the seat is manually or electrically operated, it can happen that the tilting mobility of the backrest is blocked due to deformation of the seat frame or the vehicle chassis or even a power cut.

[0019] This solution is therefore not satisfactory.

[0020] The present invention then proposes to allow the backrest to tilt using means separate from this articulation.

[0021] More particularly, the invention provides a seat frame as defined in the introduction, in which, on each side of the seat frame, a first system for fixing the backrest frame to the seat frame is adapted to form a hinge while another comprises a screw which, in a fully screwed state, blocks any rotation of the backrest frame relative to the seat frame around said hinge and which is "fusible" (i.e. which is adapted to allow the backrest frame to tilt relative to the seat frame around said hinge without having to be completely unscrewed). In particular, partial unscrewing or destruction of the screw (without unscrewing, for example by decapitating the screw by explosion) makes it fusible.

[0022] Preferably, gussets are provided on either side of the seat, which are fixed to the seat frame (or respectively the backrest) and which form an articulation for the backrest frame (or respectively the seat). The invention then proposes to use the means for fixing these gussets to the seat frame (or respectively the backrest) in order to allow, in an emergency, the backrest of the seat to be tilted backwards.

[0023] Thus, thanks to the invention, it is possible to unlock part of the attachment points of the gussets on the seat frame (or respectively the backrest) so as to allow the backrest to tilt backwards. It is understood that if the gusset is fixed to the seat frame by two bolts, unscrewing the front bolt then allows the other bolt to be used as a hinge to tilt the gusset and, therefore, the backrest.

[0024] The ability to allow this tilting without completely unscrewing the screws used makes it easier to free victims. Indeed, if the fixing screws had to be completely removed, there would need to be a lot of space on either side of the seat, which is not necessarily the case, especially when the vehicle chassis has become deformed.

[0025] It should be noted that the present solution consisting of placing a sort of "fuse" at the level of the fixing of the gussets on the seat (or back) frame is counter-intuitive since we always seek to fix these gussets on the seat (or back) frame in a particularly rigid manner, so as to prevent the back from tipping backwards in the event of a rear impact.

[0026] Other advantageous and non-limiting characteristics of the seat frame according to the invention, taken individually or in all technically possible combinations, are the following:

[0027] - the assembly means comprise a gusset which is fixed to the seat frame or, respectively, to the backrest frame by said fixing systems and which is articulated on the backrest frame or, respectively, on the seat frame to tilt around a geometric axis distinct from a geometric axis of rotation of said hinge;

[0028] - the gusset and the seat frame (or, respectively, the backrest frame) each have a first opening for the passage of the first fixing system and a second opening for the passage of said screw;

[0029] - the second opening provided in the gusset or the second opening provided in the seat frame (or, respectively, in the backrest frame) has an edge whose contour is open towards the outside by a passage of width greater than the diameter of at least part of the screw;

[0030] - said screw has a body, a head and a shoulder located between the head and the body, with a diameter between the maximum diameter of the head and the width of said passage, excluding limits;

[0031] - said screw has a fusible part (allowing the head to be automatically separated from the body of the screw);

[0032] - the first fixing system comprises another screw which has a head with a diameter strictly smaller than that of the head of said screw;

[0033] - the seat frame being placed at the front of the backrest frame, the first fixing system is located at the rear of said screw.

[0034] The invention also provides a seat as mentioned above, the seat frame and the backrest frame of which are covered with a padding.

[0035] It also provides a motor vehicle comprising a chassis and bodywork elements which delimit a passenger compartment, as well as a seat as mentioned above fixed in the passenger compartment. Of course, the different characteristics, variants and embodiments of the invention can be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other.

[0036] DETAILED DESCRIPTION OF THE INVENTIO

[0037] 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.

[0038] On the attached drawings:

[0039] [Fig. 1] is a schematic perspective view of a motor vehicle seat according to the invention;

[0040] [Fig. 2] is a schematic perspective view of part of the seat frame of Figure 1;

[0041] [Fig. 3] is a schematic side view of the seat frame portion of Fig. 2, in which the frame is shown in two distinct positions;

[0042] [Fig. 4] is a schematic sectional view along plane AA of Figure 3 of the part of the seat frame shown in said two distinct positions.

[0043] A motor vehicle (car, bus, truck, boat, plane, etc.) generally has a chassis and bodywork elements which delimit a passenger compartment.

[0044] In Figure 1, there is shown a seat 1 intended to be installed in the passenger compartment of such a motor vehicle and to be fixed to the floor of this motor vehicle.

[0045] 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.

[0046] The terms "lower" (or "bottom") and "upper" (or "top") will be used interchangeably, the lower part of an element meaning the part of that element which is located on the floor side of the vehicle and the upper part meaning the part of that element which is located on the roof side of the vehicle.

[0047] 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.

[0048] The adjective "transverse" will apply to a direction or axis oriented orthogonally to the longitudinal axes and horizontally when the vehicle is on a horizontal road. The adjectives "internal" and "external" will be used in relation to the seat 1, an external face being for example turned towards the outside of the seat when an internal face is turned towards the geometric center of the seat.

[0049] As shown in Figure 1, the seat 1 typically comprises a seat 20A, a backrest 10A and a headrest 30A, each comprising a frame and a trim attached to the frame.

[0050] The seat frame is therefore composed of these three frames. Each of these three frames is, for example, made up of metal pieces fixed together.

[0051] Here, as partly shown in Figure 2, it will be considered that the frame 10 of the backrest and the frame 20 of the seat each comprise two metal lateral flanks 11, 21, rigidly connected together by metal connecting elements. The two lateral flanks 11, 21 of each frame extend in parallel vertical planes. Of course, as a variant, these frames could be presented differently, for example in the form of plastic shells.

[0052] The seat frame could be rigidly fixed to the floor of the vehicle, but it is generally rather intended to be mounted mobile in translation on the floor. As shown in figure 1, it comprises for this purpose two longitudinal slides 40A each formed of a mobile rail fixed to the seat frame 10A, and a fixed rail fixed to the floor and on which the mobile rail slides.

[0053] The backrest frame 10A could be rigidly fixed to the seat frame 20A so that the inclination of the backrest is not adjustable, but it is generally rather designed to be mounted mobile in tilting on the seat frame.

[0054] In Figure 2, the area ensuring the connection between the lateral flanks 11, 21 of these two frames is shown. It will be noted here that the connection is ensured in the same way on both sides of the seat, so that in the following, only one of them shown in Figures 2 and following will be described here.

[0055] Here, this connection is ensured by assembly means 30 which firstly comprise a metal side called a gusset 31, which here results from a stamping operation of a sheet metal part.

[0056] This gusset 31 is designed to connect the backrest frame 10 to the seat frame 20, and more precisely one of the lateral flanks 11 of the latter to one of the lateral flanks 21 of the former.

[0057] In the illustrated embodiment, the gusset 31 is rigidly fixed to the seat frame 20, and the backrest frame 10 is mounted to move in tilting motion on this gusset 31 around a main axis A2. Of course, the opposite would be possible.

[0058] As shown in Figures 2 and 4, the gusset 31 is placed on the outer side of the seat 20 and back 10 frames, but alternatively, it could be placed on the inner side.

[0059] This gusset 31 has a generally triangular shape with rounded apexes, and it has three openings located near its apexes, two of which are lower than the third.

[0060] This third opening 313 (figure 3), the one located highest in the gusset 31, is designed to allow the backrest to tilt around the main axis A2. As shown in figure 2, it accommodates for this purpose a hinge pin 13 mounted on the backrest frame 10. This assembly is carried out in such a way that the backrest can freely tilt relative to the seat. Locking means are however provided to block this mobility. These locking means can of course be deactivated when the occupant wishes to adjust the inclination of the backrest, for example by means of a lever. This assembly being well known to those skilled in the art, it will not be described here in more detail.

[0061] The first opening 311 (figure 3), located at the bottom and at the rear of the gusset 31, preferably has a circular shape. It is located opposite a first opening (not visible in the figures) provided correspondingly in the lateral flank 21 of the seat frame 20. These first openings 311 preferably have similar shapes and dimensions.

[0062] The assembly means 30 then comprise a first fixing system 32 which is here in the form of a bolt comprising a screw 320 which is engaged through these two first openings 311, and a nut (not visible in the figures). The head of the screw 320 is here located on the outside of the seat. It then bears against the outside face of the gusset 31. The nut for its part bears against the inside face of the lateral flank 21 of the seat frame 20. Preferably, this nut is fixed to the lateral flank 21, for example by welding. Alternatively, it could have been provided that the head of the screw bears against the inside face of the lateral flank 21 of the seat frame 20 and that the nut bears against the outside face of the gusset 31.

[0063] In any case, this bolt makes it possible to hold the gusset 31 in abutment against the lateral flank 21 of the seat frame 20. It can typically be a bolt with a diameter of M8. The thread of the screw can be coated with a glue of the “thread lock” type. The tightening torque used will preferably be such that, if the gusset 31 were fixed to the seat frame 20 by this single bolt (on each side of the seat), it would be possible to manually force the backrest to tilt backwards, around the axis of this bolt, hereinafter called the safety axis A1. Thus, this bolt can act as a hinge.

[0064] The second opening 312 (figure 3), located at the bottom and at the front of the gusset 31, is located opposite a second opening provided in correspondence in the lateral flank 21 of the seat frame 20. The assembly means 30 then comprise a second fixing system 33 which is here in the form of a bolt comprising a so-called safety screw 330, and a bolt 339 (figure 4). The safety screw 330 is engaged through the two second openings. It is very preferably oriented so that its head 331 is located on the outside of the seat, so as to be easily accessible. This head 331 then bears against the outer face of the gusset 31 while the nut 339 bears against the inner face of the lateral flank 21 of the seat frame 20. Preferably, this nut is fixed to the lateral flank 21, for example by welding.

[0065] This bolt makes it possible to retain the gusset 31 in support against the lateral flank 21 of the seat frame 20. It can typically be a bolt with a diameter of M10.

[0066] The second openings 312 and / or the safety screw 330 are arranged such that:

[0067] - in the tightened state, the safety screw 330 prevents the rotation of the gusset 31 relative to the seat frame 20 around the safety axis A1, and that

[0068] - the safety screw 330 can release this rotation without having to be completely unscrewed.

[0069] In the first embodiment, that illustrated in the figures, it is the combined shapes of the second openings 312 and / or the safety screw 330 which enable this function to be ensured.

[0070] In practice, since the nut 339 is here fixed to the lateral flank 21 of the seat frame 20, it is the second opening 312 provided in the flange 31 which here has a particular shape. Of course, if the nut were fixed to the flange, it would be the second opening provided in the lateral flank 21 which had this particular shape.

[0071] Thus, in the embodiment shown, the second opening 312 of the flange 31 has an edge whose contour is open on the edge of the gusset 31. In other words, this second opening 312 forms a hollow notch in the edge of the gusset 31.

[0072] This second opening 312 has an arc-shaped bottom and a straight part opens outwards to communicate the bottom of the opening with the outside of the gusset 31. This straight part delimits a passage of constant width L1. Alternatively, this passage could have a variable width, in which case the width L1 considered would correspond to the smallest gap between the two edges of the straight part of the opening. It could be provided that the arc-shaped bottom of this second opening 312 extends over an angular sector strictly less than 180 degrees. But in this eventuality, it is understood that in the event of a rear impact on the vehicle, the forces exerted on the backrest 10A would tend to tilt the backrest frame 10 and the gusset 31 towards the rear, around the safety axis A1, by unhooking the second opening 312 from the safety screw 330.

[0073] To avoid this, and preferably, the arc-shaped bottom of the second opening 312 extends over an angular sector strictly greater than 180 degrees, here of the order of 270 degrees.

[0074] The two parallel edges of the right part of the second opening 312 extend for their part along an axis orthogonal, to within a few degrees, to the axis passing through the centers of the first and second openings. Thus, when the gusset 31 pivots around the safety axis A1 towards the front, the second opening 312 can hook onto the safety screw 330.

[0075] As shown in Figure 4, the safety screw 330 has a head 331 and a threaded body 332, which are connected by an intermediate portion forming a shoulder 333.

[0076] The head 331 has a support part 331B, here circular, and, on an external face, an imprint 331A allowing the screw to be operated. This imprint is here of the male type. It therefore extends in projection from the support part, which facilitates its handling.

[0077] The support portion 331 B has a diameter greater than that of the arc-shaped bottom of the second opening 312. It can therefore rest on the edge of this opening.

[0078] The shoulder 333 is designed to be placed in the arc-shaped bottom of the second opening 312. It then has a circular shape of diameter equal, apart from the mounting clearance, to the diameter of the arc-shaped bottom of the second opening 312. It rises from the internal face of the support part 331 B of the head of the safety screw 330.

[0079] Finally, the threaded body 332 extends from the internal face of this shoulder, parallel to the safety axis A1. It has a diameter smaller than the width L1 of the passage left by the second opening 312. Here it is threaded over only part of its length.

[0080] As shown in Figure 3 (in solid line) and the left part of Figure 4, thanks to its shape, when screwed into the nut, the safety screw 330 blocks the gusset 31 in a fixed position. Indeed, its shoulder 333 is housed in the arc-shaped bottom of the second opening 312, so that the gusset cannot pivot around the safety axis A1.

[0081] On the other hand, as shown in Figure 3 (in broken lines) and the right-hand part of Figure 4, when the body 332 of the safety screw 330 is unscrewed over a part of its length, here over a length equal to the thickness of the gusset 31, the shoulder 333 comes entirely out of the arc-shaped bottom of the second opening 312, which releases the pivoting mobility of the gusset 31 around the safety axis A1.

[0082] Thus, in the event of an accident, if the emergency services wish to extract the occupant from his seat by passing him through the luggage compartment of the vehicle, they can unscrew the safety screws 330 over a small part of their lengths, then tilt the backrest 10A around the safety axis A1. The aforementioned assembly means 30 will then allow the backrest to be tilted backwards horizontally (possibly by removing the rear seats from the vehicle). It will be noted that the mobility of the backrest around the main axis A2 allows the backrest to be tilted backwards but this mobility, on the one hand, could be unavailable due to the damage caused to the vehicle during the accident, and on the other hand, is not designed to allow the backrest to be tilted over a sufficient travel, to a horizontal position.In addition, the position of the safety axis A1, below the main axis A2, ensures that the backrest tilts into a more suitable position for extracting victims.

[0083] The present invention is in no way limited to the embodiment shown, but those skilled in the art will be able to provide any variation in accordance with the invention.

[0084] Typically, the second opening (312) and the fixing screw (330) could have shapes different from those illustrated in the figures. For example, the bottom of the second opening could have a non-circular shape (typically hexagonal). In another variant, the bolt engaged in the first opening (311) of the gusset could be replaced by a shouldered pin equipped with a circlip.

[0085] In a second embodiment, the second opening (312) provided in the gusset and the corresponding opening in the lateral flank of the seat frame could have closed contours, for example circular. In this second embodiment, the safety screw will have a fusible part (for example by pyrotechnics) allowing the head of the screw to detach from the threaded body to release the rotational mobility of the gusset around the safety axis (A1). This fusible part will preferably be manually controllable by the emergency services, for example via an external power supply. For example, explosive screws such as those used on fighter aircraft could be used to separate the canopy from the rest of the fuselage in the event of the pilot ejecting.

[0086] In a third embodiment, the invention could be applied to a seat whose backrest would be devoid of means for adjusting its inclination. In this embodiment, the frame of the backrest would be directly fixed to the frame of the backrest, without using a gusset. This fixing could be done by two fixing screws on each side of the seat, each engaged through openings provided in these two frames. Then, similarly to the embodiment illustrated in the figures, one of these openings could be in the form of a notch, with an arc-shaped bottom and a passage to the outside of a width less than the diameter of the bottom.

[0087] In a fourth embodiment quite close to that illustrated in the figures, the gusset could be located on the inside of the lateral flank of the seat frame. The safety screw would then be oriented head to tail with respect to the illustrated embodiment, with its head on the inside of the seat. This embodiment may be preferred to that illustrated in the figures for the following reason. A seat is conventionally sized to resist lateral compression in the event of a side impact on the vehicle, in order to preserve a survival space for the occupant. This survival space is obtained in particular using the rigid tubes which connect the two lateral flanks of the seat frame. Consequently, by placing the screw head on the inside of the seat, it is ensured that access to this screw head will be possible even in the event of deformation of the chassis.

Claims

CLAIMS

1. Seat frame comprising: - a backrest frame (10), - a seat frame (20), and - means (30) for assembling the backrest frame (10) on the seat frame (20), which comprise, on each side of the seat frame, two fixing systems (32, 33) such as bolts, characterized in that, on each side of the seat frame, a first of the fixing systems (32) is adapted to form a hinge while the other fixing system (33) comprises a screw (330) which, in a fully screwed state, blocks any rotation of the backrest frame (10) relative to the seat frame (20) around said hinge and which is adapted to allow the backrest frame (10) to tilt relative to the seat frame (20) around said hinge without having to be completely unscrewed.

2. Seat frame according to claim 1, wherein the assembly means (30) comprise a gusset (31) which is fixed to the seat frame (20) or, respectively, to the backrest frame (10) by said fixing systems (32, 33) and which is articulated on the backrest frame (10) or, respectively, on the seat frame (20) to tilt around a geometric axis (A2) distinct from a geometric axis (A1) of rotation of said hinge.

3. Seat frame according to claim 2, in which the gusset (30) and the seat frame (20) or, respectively, the backrest frame (10) each have a first opening for the passage of the first fixing system (32) and a second opening (312) for the passage of said screw (330).

4. Seat frame according to claim 3, in which the second opening (312) provided in the gusset (30) or the second opening which is provided in the seat frame (20) or, respectively, in the backrest frame (10), has an edge whose contour is open towards the outside by a passage of width (L1) greater than the diameter of at least a part of the screw (330).

5. Seat frame according to claim 4, wherein said screw (330) has a body (332), a head (331) and a shoulder (333) located between the head (331) and the body (332), with a diameter between the maximum diameter of the head (331) and the width (L1) of said passage, limits excluded.

6. A seat frame according to claim 3, wherein said screw has a fusible part.

7. Seat frame according to one of claims 1 to 6, in which the first fixing system (32) comprises another screw which has a head with a diameter strictly smaller than that of the head (331) of said screw (330).

8. Seat frame according to one of claims 1 to 7, in which, the seat frame (20) being placed at the front of the backrest frame (10), the first fixing system (32) is located at the rear of said screw (330).

9. Seat (1) comprising a frame according to one of claims 1 to 8, the seat frame (20) and the backrest frame (10) of which are covered with a padding.

10. Motor vehicle comprising a chassis and bodywork elements which delimit a passenger compartment, characterized in that it further comprises a seat (1) according to claim 9, fixed in said passenger compartment.

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