Tilting seat frame

Abstract

The invention relates to a seat frame (2) comprising: - a backrest frame (10), - a seat frame (20), and - means for assembling the backrest frame onto the seat frame, which include, on each side of the seat frame, two fastening systems, the first of the fastening systems comprising a nut and a screw having a head and a threaded body screwed into the nut. According to the invention, said screw has a fusible zone of lower torsional and / or tensile strength than the head and threaded body, which is located between the head and the threaded body. Figure for the abstract: Fig. 4

Description

Title of the invention: Tilting seat frame Technical field of the invention

[0001] The present invention relates generally to the field of seats.

[0002] It relates more particularly to a seat frame comprising: - a backrest frame, - a seat frame, and - means for assembling the backrest frame with the seat frame, which comprise, on each side of the seat frame, two fixing systems, at least one of the fixing systems comprising a nut and a screw which has a head and a threaded body screwed into the nut.

[0003] The invention also relates to a seat comprising such a frame, and a vehicle equipped with such a seat. State of the art

[0004] 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 allowing passengers to adjust their positions.

[0005] These seats are of two types, namely manually operated and electrically operated.

[0006] Typically, a seat is known comprising a seat frame and a backrest frame articulated 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 articulated so that it can tilt forwards or backwards.

[0007] These frames are designed so as not to deform excessively in the event of an accident.

[0008] However, it sometimes happens 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.

[0009] In this eventuality, the solution currently used consists of cutting the vehicle's uprights so as to remove the roof to provide easier access to the victims.

[0010] Unfortunately, this solution requires the use of powerful cutting pliers, which emergency services must be equipped with. Even if they had them, this operation takes a long time to implement, which can have serious consequences for the victims. Presentation of the invention

[0011] It is in this context that the applicant sought new solutions to facilitate the extrication of victims.

[0012] One idea is to tilt the backrest backwards, horizontally, so that victims can be extracted through the luggage compartment.

[0013] For this purpose, the aforementioned mobility of tilting the backrest relative to the seat could be used.

[0014] But whether the seat is manually or electrically controlled, it happens 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.

[0015] This solution therefore does not prove satisfactory.

[0016] The present invention then proposes to allow the backrest to tilt using means separate from this articulation.

[0017] More particularly, the invention provides a seat frame as defined in the introduction, in which the screw has a fusible zone of lower resistance to torsion and / or traction than the head and the threaded body, which is located between the head and the threaded body.

[0018] Thus, if a significant torque is applied to the screw head, it is possible to allow the screw to break at the fusible zone.

[0019] 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 the event of an emergency, the backrest of the seat to be tilted backwards.

[0020] Thus, thanks to the invention, by applying a very high torque to a screw head in order to break it, it is possible to unlock part of the fixing points of the gussets on the seat frame (or respectively backrest) so as to allow the backrest to tilt backwards. It is understood in fact that if each gusset is fixed to the seat frame by two bolts, the breakage of one of the bolts fixing the gussets to the seat frame (or respectively backrest) then allows the other bolt to be used as a hinge to tilt the gusset and, therefore, the backrest.

[0021] The fact that this tilting can be achieved without having to completely unscrew the screws used makes it easier to free victims. Indeed, if the fixing screws had to be completely removed, there would have to be a lot of space on either side of the seat, which is not necessarily the case, in particular when the vehicle chassis has deformed.

[0022] A final advantage is that when the backrest tilts, it pivots around an axis located low enough so that, once the backrest is completely tilted, it is in line with the seat, which then makes it easier for the victim to slide towards the luggage compartment.

[0023] 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: - the fusible zone is delimited by an annular groove provided in a hollow in said screw - said head being in contact with a wall of the backrest or seat frame, said screw being threaded through a passage opening provided in said wall, said fusible zone is located at a distance from the head equal to the thickness of said wall on the edge of the passage opening; - the threaded body having a diameter which is associated in a standard manner with a standardized screw head dimension, said head having a dimension greater than said standardized dimension; - the seat frame being placed at the front of the backrest frame, the first fixing system is located at the front of the other fixing system; - the other fixing system comprises another screw identical to the said screw; - the other fixing system is adapted to form a hinge to allow, if said screw breaks, the tilting of the backrest frame relative to the seat frame; - the assembly means comprise a gusset which is fixed to a component of the seat frame (or, respectively, of 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.

[0024] The invention also provides a seat comprising a frame as mentioned above, the seat frame and the backrest frame of which are covered with a padding.

[0025] It also provides a motor vehicle comprising a chassis, bodywork elements which delimit a passenger compartment, and a seat as mentioned above, fixed in said passenger compartment.

[0026] 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

[0027] 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.

[0028] In the attached drawings:

[0029] [Fig-1] is a schematic perspective view of a motor vehicle seat in accordance with the invention;

[0030] [Fig.2] is a schematic view of part of the means for assembling the frames seat and backrest of the seat frame of [Fig.l];

[0031] [Fig.3] illustrates two schematic sectional views, one along plane AA of the [Fig.2] and the other representing a homologous view of the first, but after the breakage of a screw of the assembly means illustrated in [Fig.2];

[0032] [Fig.4] is a schematic side view of the seat frame of [Fig.l], after the breakage of the said screw.

[0033] A motor vehicle (car, bus, truck, boat, airplane, etc.) generally has a chassis and bodywork elements which delimit a passenger compartment.

[0034] In [Fig.l], 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.

[0035] 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.

[0036] 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 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.

[0037] 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.

[0038] 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.

[0039] The adjectives “internal” and “external” will be used in relation to 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.

[0040] As shown in [Fig.l], the seat 1 conventionally comprises a seat 20A, a backrest 10A and a headrest 30A, each comprising a frame and a trim attached to the frame. It will be noted that the frame of the backrest and that of the headrest could be confused.

[0041] As shown in [Fig.4], the frame 2 of the seat is therefore composed of at least one seat frame 20 and one backrest frame 10. Each of these frames is for example formed of metal parts fixed together.

[0042] Here, it will be considered that the backrest frame 10 and the seat frame 20 each comprise two metal lateral flanks 11, 21, rigidly connected together by metal connecting elements (not visible). 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.

[0043] The seat frame 20 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 [Fig.l], it is mounted for this purpose on two longitudinal slides 40A each formed of a mobile rail fixed to the seat frame 20, and a fixed rail fixed to the floor and in which the mobile rail slides.

[0044] The backrest frame 10 could be rigidly fixed to the seat frame 20 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 around a transverse geometric axis, hereinafter called pivot axis A2.

[0045] In [Fig. 2], the area ensuring the connection between the lateral flanks 11, 21 of these two frames is shown in detail. 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 3 will be described here.

[0046] Here, this connection is ensured by assembly means 30 which firstly comprise a metal wall called a gusset 31, which here results from a stamping operation of a sheet metal part.

[0047] This gusset 31 is designed to connect one of the lateral flanks 11 of the backrest frame 10 to one of the lateral flanks 21 of the seat frame 20.

[0048] In the illustrated embodiment, the gusset 31 is fixed to the lateral flanks 21 of the seat frame 20 (it is therefore considered to be part of this seat frame), and the backrest frame 10 is articulated on it around the pivot axis A2.

[0049] As shown in Figures 2 and 4, the gusset 31 is placed on the inner side of the lateral flanks 21 of the seat frame 20, but as a variant, it could be placed on the outer side.

[0050] This gusset 31 generally has a triangular shape with rounded apexes, and it has three openings located near its apexes, two of which are lower than the third.

[0051] The first two openings 310 ([Fig.3]) preferably have circular shapes. They are located opposite two openings provided in correspondence in the lateral flank 21 of the seat frame 20. These openings have similar dimensions here.

[0052] The third opening 35 ([Fig.2]), the one located highest in the gusset 31, is designed to allow the backrest 10A to tilt around the pivot axis A2. For this purpose, it accommodates, for example, a hinge axis mounted on the backrest frame 10. This assembly being well known to those skilled in the art, it will not be described in detail here.

[0053] The assembly means 30 of the backrest frame 10 on the seat frame 20 further comprise two fixing systems 32, 33 engaged respectively through the first two openings in order to rigidly fix the gusset 31 to the corresponding lateral flank 21 of the seat frame 20.

[0054] These two fixing systems 32, 33 are provided so that, if necessary, one can give way and the other resist and thus form a hinge, so that the gusset and the backrest can pivot backwards, as illustrated in [Fig.4].

[0055] In the embodiment illustrated in the figures, the fixing system 32 which is intended to yield is the one which is engaged through the front opening of the gusset 31, while the fixing system 33 which is intended to allow the backrest to tilt relative to the seat is the one located furthest to the rear.

[0056] The front fixing system 32 is the one which is more precisely the subject of the present invention.

[0057] As shown in [Fig. 3], it is in the form of a bolt comprising a so-called safety screw 320, and a bolt 329. The safety screw 320 is engaged through one of the first openings 310 of the gusset 31 and the corresponding opening 210 of the lateral flank 21 of the seat frame 20. It is elongated along a geometric axis passing through the centers of the aforementioned openings, hereinafter called the safety axis AL

[0058] This safety screw 320 comprises a head 321, a threaded body 322 and a fusible zone 323 located between the head 321 and the threaded body 322. It may also comprise, as is the case in the figures, a free, non-threaded end located in the extension of the threaded body 322.

[0059] It is here oriented such that its head 321 is located on the outside of the seat 1, so as to be easily accessible. This head 321 then rests against the outside face of the lateral flank 21 of the seat frame 20 while the nut 329 rests against the inside face of the gusset 31. This nut 329 will preferably be fixed to the gusset 31, for example by welding.

[0060] This bolt makes it possible to retain the gusset 31 in abutment against the lateral flank 21 of the seat frame 20.

[0061] The head 321 here has a maneuvering part, allowing the screw to be maneuvered. safety, and a support part shaped to rest against the lateral flank 21 of the seat frame 20.

[0062] The operating part preferably has a hexagonal shape, so that the screw can be operated radially, from the luggage compartment of the vehicle, using a flat wrench. According to a variant, it could have a hollow imprint in its end, for example of hexagonal or star shape in order to be able to receive an Allen or Torx® type key.

[0063] The support part here forms a collar around the operating part on the side of the threaded body 322. This collar here has a circular shape.

[0064] This support part makes it possible to maximize the support surface of the head 321 against the lateral flank 21 of the seat frame 20, so as to avoid any deformation of the head or the lateral flank 21 when tightening the safety screw 320.

[0065] The fusible zone 323 is then located between this support part of the head 321 and the threaded body 322. In practice, the safety screw 320 has an annular groove of revolution around the safety axis AL

[0066] This groove extends hollow relative to the threaded body 322. It has an invariable profile all around the safety axis A1 but as a variant, it could be otherwise. Typically, it could be formed of a plurality of radial holes distributed all around this axis.

[0067] In any case, the fusible zone 323 makes it possible to significantly reduce the resistance to twisting and traction of the safety screw 320.

[0068] Thus, the breaking of the safety screw 320 when it is placed under increasingly intense stresses always occurs in this fusible zone.

[0069] In the following, we will distinguish two tightening torques for the bolt.

[0070] The standard tightening torque will be the required tightening torque of the safety screw in the bolt, to prevent loosening during the seat screw. This is therefore the torque that is applied when assembling the seat 1.

[0071] The breaking torque will be the tightening torque which will allow the safety screw 320 to break into two parts, at the level of the fusible zone 323.

[0072] The groove is positioned along the safety screw 320 so that, once the nut is tightened to the standard tightening torque on the screw, the bottom of the groove is in the support plane of the gusset against the lateral flank 21 of the seat frame 20. Thus, when the applied tightening torque exceeds the breaking torque, the screw will break along this plane and it will be possible to slide the gusset 31 against the lateral flank 21 to allow the backrest to tilt backwards, into the position illustrated in [Fig.4].

[0073] Here, the threaded body 322 of the safety screw 320 has a standardized diameter, for example to the M10 standard.

[0074] The head of the safety screw 320 also has a standardized dimension, but to a larger standard than that of the threaded body 322, for example to the M14 standard.

[0075] The head of the security screw therefore does not have the dimensions of a standard M10 screw but of a standard M14 screw.

[0076] This aspect has a main advantage, which is that it is possible to apply a very high tightening torque to the screw head 321 by means of a flat wrench without risking seeing this head deform before reaching the required torque.

[0077] Indeed, as explained above, the screw is designed to be tightened to a standard tightening torque when assembling the seat 1, but also to be tightened to a breaking torque if necessary.

[0078] The standard tightening torque depends in particular on the strength class of the material used to manufacture the bolt. Typically, it could be 49 or 83 NM respectively.

[0079] It should be noted that a standard M14 screw could be screwed to a standard tightening torque of 138 or 233 Nm respectively. It can therefore be seen that a standard M14 screw is designed to withstand a torque almost three times greater than a standard M10 screw.

[0080] The safety screw 320 is also designed to be tightened until the fusible zone 323 breaks if necessary. The minimum diameter of the screw, located at the fusible zone, will then be chosen so that the breaking torque is much higher than the standard tightening torque (at least 25% higher). Taking into account the diameter of the head 321 (to the M14 standard), this breaking torque will be chosen to be, however, lower than the standard tightening torque of a screw to the M14 standard.

[0081] In practice, the safety screw 320 is designed so that the breaking torque is between one and a half and two times the standard tightening torque.

[0082] Of course, as a variant, the screw could have a threaded body of smaller diameter (for example standard M7, M8 or M12), in which case the head would also have a different diameter, preferably a standard twice as large (respectively standard M10, M12 or M16)

[0083] Here, the chosen bolt has a resistance class of 10.9.

[0084] As shown in [Fig.2], the other fastening system 33, the one engaged through the rear opening of the gusset 321, is here in the form of a bolt.

[0085] In a first embodiment, this will be a bolt identical to that of the fixing system 32 (with a fusible zone and a large screw head). This will not only restrict the number of part references required for the assembly of the seat, but also allow the backrest to be completely separated from the seat if necessary, by breaking the four screws fixing the gussets.

[0086] Alternatively, it could be a conventional bolt (without a fusible zone), as standard M8 or MIO.

[0087] The tightening torque used to tighten this bolt will then preferably be such that, when the gusset 31 is fixed to the seat frame 20 by this single bolt (on each side of the seat), it is possible to manually force the backrest to tilt backwards, around the geometric axis of this bolt, hereinafter called hinge axis A3. Thus this bolt can act as a hinge.

[0088] We can now describe how, in the event of an accident, the emergency services can operate if they wish to extract the occupant from the vehicle by passing them through the luggage compartment.

[0089] The first operation will consist of removing any hood hiding the gusset 31 and its fixing systems 32, 33 and possibly removing any rear seats from the vehicle which would hinder access to seat 1 where the victim is located.

[0090] Then, it will be possible to break one of the two safety screws 320 on each side of the seat 1, by applying to them a tightening torque equal to the breaking torque. The breaking of the safety screws 320 taking place in the support plane of the gussets 31 against the lateral flanks 21 of the seat frame 20, an individual will be able without the aid of a tool to force the backrest 10A to tilt around the hinge axis A3.

[0091] It will be noted that the mobility of the backrest around the pivot 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 stroke, to a horizontal position. In addition, the position of the hinge axis A3, below the pivot axis A2, ensures that the backrest can be tilted into a more suitable position for extracting victims.

[0092] The present invention is in no way limited to the embodiment shown, but those skilled in the art will be able to provide any variant in accordance with the invention.

[0093] Typically, the bolt engaged in the rear opening of the gusset (along the hinge axis) could be replaced by a shouldered axis equipped with a circlip, such an axis forming a perfect hinge.

[0094] In another variant, the openings provided in the gusset or the lateral flank of the seat frame could have shapes different from those illustrated in the figures (typically octagonal).

[0095] In one embodiment, the gusset could be located on the outer side of the lateral flank of the seat frame. The safety screw could then possibly be oriented head-to-tail compared to the illustrated embodiment, with its head oriented on the inner side of the seat, but it would then be necessary to provide easy access to this screw head.

[0096] In another embodiment, the gusset could belong not to the seat frame but to that of the backrest. In this mode, the two fixing systems (32, 33) would therefore allow the gusset to be fixed to the corresponding lateral side of the backrest.

[0097] In another embodiment, the safety screw could be broken in another way, typically by means of a pyrotechnic device or an electrically controlled Tini™ Frangibolt® type actuator. This device could, for example, be in the form of a ring threaded onto the screw and which, when it receives an electric current, expands and thus greatly increases the tensile forces supported by the screw, until the latter breaks.

Claims

Claims

1. Seat frame (2) 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), a first of the fixing systems (32) comprising a nut (329) and a screw (320) which has a head (321) and a threaded body (322) screwed into the nut (329), characterized in that said screw (320) has a fusible zone (323) of lower resistance to torsion and / or traction than the head (321) and the threaded body (322), which is located between the head (321) and the threaded body (322).

2. Seat frame (2) according to claim 1, in which the fusible zone (323) is delimited by an annular groove provided in said screw (320).

3. Seat frame (2) according to claim 1 or 2, wherein said head (321) rests against a wall (21) of the backrest frame (10) or seat frame (20), said screw (320) being threaded through a passage opening (210) provided in said wall (21), said fusible zone (323) is located at a distance from the head (321) equal to the thickness of said wall (21) at the edge of the passage opening (210).

4. Seat frame (2) according to one of claims 1 to 3, in which the threaded body (322) having a diameter which is associated in a standard manner with a standardized screw head dimension, said head (321) having a dimension greater than said standardized dimension.

5. Seat frame (2) according to one of claims 1 to 4, 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 front of the other fixing system (33).

6. Seat frame (2) according to one of claims 1 to 5, in which the other fixing system (33) comprises another screw identical to said screw (320).

7. Seat frame (2) according to one of claims 1 to 6, in which the other fixing system (33) is adapted to form a hinge to allow, if said screw (320) breaks, the tilting of the backrest frame (10) relative to the seat frame (20).

8. Seat frame (2) according to claim 7, in which the assembly means (30) comprise a gusset (31) which is fixed to a component (21) of the seat frame (20) or, respectively, of 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 (Al) of rotation of said hinge.

9. Seat (1) comprising a frame (2) according to one of claims 1 to 8, the seat frame (20) and the backrest frame (10) of which are covered with a lining.

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 8, fixed in said passenger compartment.

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