Vehicle seat including an armrest compatible with side airbag deployment
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- RENAULT SA
- Filing Date
- 2024-11-25
- Publication Date
- 2026-05-29
AI Technical Summary
Conventional armrest solutions in vehicle seats are not compatible with the reliable deployment of side airbags installed on the inside of the seat, as they interfere with the airbag's deployment path.
An L-shaped armrest design with a pivoting joint and elastic element that allows the armrest to move between stable first and second positions, ensuring the airbag has sufficient space for deployment by maintaining intermediate positions as mechanically unstable.
The L-shaped armrest design ensures efficient and repeatable deployment of the side airbag by preventing interference, while providing a comfortable and intuitive user experience.
Abstract
Description
Title of the invention: Vehicle seat comprising an armrest compatible with side airbag deployment
[0001] The present invention relates to vehicle seats comprising an armrest. In motor vehicles, it is common to provide an armrest on the driver's seat, this armrest being located on the right side for right-hand drive vehicles and on the left side for left-hand drive vehicles. In other words, the armrest is located on the inside of the driver's seat. We are interested in cases where such an armrest is mounted on the seat back frame.
[0002] Furthermore, passive safety protection means are provided, including airbags which inflate in a fraction of a second if necessary following an impact suffered by the vehicle.
[0003] In the trade and in common parlance, the term 'airbag' is used to designate such an inflatable bag. Similarly, the term 'airbag system' is used to designate the passive safety protection system.
[0004] It is known to install an airbag in the back of the seat, on the side, to contribute to the lateral protection of the occupant present in the seat in question.
[0005] In particular, it is known to install an airbag on the outside of the seat, that is to say on the side where the bodywork is located which separates the interior of the vehicle from the exterior of the vehicle.
[0006] A need arose to also offer an airbag on the inside of the seat, that is to say on the side where the armrest is located.
[0007] However, conventional armrest solutions are not compatible with the reliable deployment of said airbag. The inventors sought to address this need.
[0008] To this end, a vehicle seat is proposed here comprising a backrest frame pivotally mounted on a seat frame, the vehicle seat being equipped with an airbag on one side (particularly on the inner side), the vehicle seat being located in an orthogonal spatial frame comprising a vertical direction, a longitudinal direction, and a transverse direction, the vehicle seat comprising an armrest connected via an articulated mounting to the backrest frame, the armrest being located on the first side, the armrest being movable between a first position, referred to as lowered, and a second position, referred to as raised, the armrest comprising a first portion extending from the articulated mounting in a first direction of extension and a second portion extending the first portion along a second direction of extension inclined at an angle to the first direction of extension, The first and second positions are each mechanically stable and indexed, while all intermediate positions are generally mechanically unstable. The articulated assembly includes an elastic element to return the armrest to the first or second position. Each of the first and second positions leaves sufficient space for the deployment of the airbag from a lateral area of the seat back on the first side.
[0009] In practice, the armrest is generally L-shaped. The first portion is the smaller and is in the normal operating position, raised from the hinge. The second portion is longer and is in the normal operating position, horizontal or slightly downwards towards the front, suitable for comfortably supporting the driver's forearm.We will see later that the L-shape does not necessarily present a right angle at the intersection of the two portions. Furthermore, the available angular travel between the first lowered position and the second raised position will be discussed further below.
[0010] Thanks to the arrangements described above, a configuration is proposed which cleverly combines the presence of a liftable armrest on the inside of the seat and a side airbag on the same side of said seat.
[0011] Advantageously, the articulated mounting is such that the intermediate positions of the armrest between the lowered and raised positions are unstable and cannot be maintained. Even if these intermediate positions could cause interference with the deployment of the airbag, these positions can only exist during a deliberate maneuver by the driver and cannot prevail under normal driving conditions.
[0012] Regarding the shape of the armrest, the part interposed between the first portion and the second portion can form an intermediate angled area.
[0013] According to one embodiment, the articulated assembly is a pivoting joint, preferably with a transverse axis.
[0014] This is a mechanically simple assembly; the kinematics of the armrest between the lowered and raised positions is intuitive for the user.
[0015] It is noted that the pivot axis is located lower than that of a conventional armrest, which is generally straight. This downward offset of the rotation axis frees up space on the side of the backrest, which is conducive to the efficient and repeatable deployment of the airbag. Cleverly, it is the L-shaped design of the armrest that allows for this downward offset of the joint.
[0016] It should be noted that the articulated assembly could be based on a different system than a pivot joint, for example the articulated assembly could use a kinematic based on a deformable quadrilateral, e.g. a four-bar mechanism configuration.
[0017] According to one embodiment, concerning the pivoting assembly, the first position is angularly separated from the second position by an angular gap (0c) between 90° and 120°.
[0018] According to a particular embodiment, this angular deviation can be chosen to be close to 110°.
[0019] Thanks to the above provisions, when the armrest is raised, the 2nd portion of the armrest is located behind the side of the backrest, thus freeing up the passage for the deployment of the airbag if it happens to deploy.
[0020] According to one embodiment, an angular stroke is provided between the first position and the second position, with a first angular range where the armrest is returned by the elastic member to the first position, and a second angular range where the armrest is returned by the elastic member to the second position.
[0021] According to one embodiment, the articulated assembly includes a fixing plate to the backrest frame.
[0022] Advantageously, the plate includes fixing holes which are located opposite holes already provided on the side flange of the backrest.
[0023] It should be noted that the armrest system promoted here may be offered as an option, fitted or not, depending on the equipment of the seat and / or the vehicle
[0024] The mounting plate is the only mechanical interface between the armrest system and the seat back; it is very robust. Note that the holes in the side flange of the seat frame may already be present.
[0025] According to one embodiment, the articulated assembly includes a bracket (5) welded to the plate, the bracket contributing to the indexing of each of the first and second positions. The bracket acts as an angular stop for the raised and lowered positions, and the bracket forms the mounting support for the tubular bearing in which the shaft rotates, the tubular bearing absorbing most of the forces transmitted from the armrest to the seat back.
[0026] Indeed, the armrest is mounted in a cantilever mounting system.
[0027] According to one embodiment, the articulated assembly includes a shaft attached to the armrest, the shaft being provided with a cam cooperating with the elastic element formed like a spring cooperating with the cam.
[0028] The spring can be a spring working in compression, such as a helical spring, or a spring working in bending such as a leaf spring.
[0029] According to one embodiment, the articulated assembly comprises a single elastic element, which makes it possible to ensure the indexing of the two extreme positions of the angular stroke.
[0030] According to one embodiment, a roller pushed by a compression spring may be provided, the roller forming a cam follower that presses on the cam. Such a rolling roller solution exhibits low friction and good spring elasticity.
[0031] According to one embodiment, the shaft is received in a tubular bearing welded to the yoke. This creates the rotational degree of freedom while preventing other rotational movements. Translation along the Y-axis can be stopped by various means, e.g., a circlip, a key, etc.
[0032] According to one embodiment, a guard gap is provided along the transverse direction between the padding of the backrest and the armrest.
[0033] According to one embodiment, the guard interval can be at least 3 mm, or even at least 4 mm.
[0034] Advantageously, this ensures that there is no friction between the armrest and the seat back, even when a seat cover is in place. This guarantees that intermediate positions will be sufficiently unstable and returned to one of the extreme end positions by the elastic return system.
[0035] The present invention also relates to a motor vehicle, comprising a seat as described above.
[0036] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.1] schematically represents in profile view a vehicle seat in which the present invention is implemented, the two extreme angular positions of the armrest being shown in the figure; - [Fig.2] schematically represents an exploded view of the armrest and the articulated assembly which connects it to the backrest frame; - [Fig.3] schematically illustrates in perspective the armrest in the raised position; - [Fig.4] schematically illustrates in perspective the armrest in position lowered; - [Fig.5] shows an example of an articulated assembly, in front view; - [Fig.6] shows the articulated assembly of [Fig.5], in perspective view; - [Fig.7] shows the articulated assembly of [Fig.5], in profile view; - [Fig.8] is a diagram showing an example of a cam system and spring with the armrest in the raised position; - [Fig.9] is a diagram showing the example of [Fig.8], illustrating the cam and spring system with the armrest in the lowered position; - [Fig. 10] is a diagram showing the example of [Fig.8], illustrating the cam and spring system with the armrest in the intermediate position; - [Fig. 11] schematically illustrates an example of inflatable bag deployment; - [Fig. 12] shows a front view of the lateral area of the backrest with the armrest raised; - [Fig. 13] illustrates another example of an elastic return system.
[0037] In the various figures, the same reference numerals designate identical or similar elements. For clarity, some elements are not necessarily shown to scale.
[0038] Fig. 1 shows a vehicle seat, of which only the seat frame 98 and the backrest DOS have been represented.
[0039] As known in itself, the backrest is mounted on the seat frame with a possible adjustment in inclination, that is to say in rotation around a transverse axis noted Yl.
[0040] It should be noted that the invention covers all types of motor vehicles, including passenger cars, commercial vehicles, vans, and recreational vehicles. The invention relates in particular to the driver's seat, but it can also be applied to other seats in the vehicle.
[0041] The seat of interest is equipped with a flip-up armrest, usually marked 6.
[0042] Position PI (called first position) designates the normal position of use, in which the seat occupant can rest his forearm on the top of a part of the armrest.
[0043] Position P2 (second position) designates the raised position. In this position, the space normally occupied by the armrest is freed up and the driver can have direct access with their arm to the passenger seat without obstruction.
[0044] Figures show an armrest located on the right side of the seat.
[0045] Of course, the invention can be applied mutatis mutandis to the left side of the seat particularly concerning the driver's seat in right-hand drive vehicles.
[0046] In the figures, the seat is located with respect to an orthogonal frame of reference as follows: the vertical direction is noted Z, the horizontal direction called longitudinal is noted X, the horizontal direction called transverse is noted Y.
[0047] In the example shown in the figures, the armrest is mounted pivoting relative to the backrest around a pivot axis Y2 parallel to the transverse direction Y.
[0048] The pivot axis Y2 of the L-shaped armrest is located below the pivot axis of a conventional straight armrest. The pivot axis Y2 of the L-shaped armrest is located above the tilt axis Yl of the backrest.
[0049] The angular travel between the first position PI and the second position P2 is here approximately 110°. In general, the available angular travel, that is to say the gap The angular angle Oc between the first position and the second position can be chosen between 90° and 120°.
[0050] It should also be noted that although the figures represent an articulated mounting solution based on pivoting about a transverse axis, it is not excluded to use other kinematic solutions to be able to move the armrest from a (lowered) operating position to a raised position.
[0051] It can thus be stated that the armrest 6 is connected to the backrest frame 1 via an articulated assembly generally identified as 10.
[0052] The backrest frame 1 is generally made up of two side flanges which extend from top to bottom, the two side flanges being connected securely by crossbars.
[0053] The armrest 6 is mounted on one of the two side flanges in a cantilevered mounting configuration. In the illustrated example, this is the right side flange 92.
[0054] Furthermore, the vehicle seat is equipped with an inflatable bag ('airbag') on the same side of the backrest.
[0055] As seen in [Fig. 12], the side airbag is housed in its folded configuration 94, just outside the right side flange 92 of the seat back. Deployment of the side airbag is triggered by the activation of an igniter 96 as known per se.
[0056] As seen in [Fig.2], the armrest 6 comprises a first portion 61 extending from the articulated assembly 10 along a first extension direction W1 and a second portion 62 extending the first portion along a second extension direction W2.
[0057] In other words, the second portion 62 extends obliquely from the first portion 61.
[0058] The second extension direction W2 is inclined relative to the first extension direction Wl, at an angle of at least 60°, in practice close to a right angle.
[0059] In other words, the armrest 6 is generally L-shaped, the first portion 61 is the smaller and is in the normal position of use in an upward posture from the joint, the second portion 62 is longer and is in the normal position of use in a horizontal or slightly downward forward position, as seen in [Fig.1].
[0060] It is noted that the L-shaped form does not necessarily present a right angle at the intersection of the two portions.
[0061] In the illustrated example, the first portion 61 and the second portion 62 are connected by an angled area 63 with gently transitioning shapes.
[0062] With respect to the joint, the first portion can be called the 'proximal portion' and the second portion the 'distal portion'.
[0063] As seen in [Fig.2], the armrest 6 comprises a metal frame 60, a structural plastic support piece 65, and a foam cover 66.
[0064] The length of the first portion 61 can typically be between 100 mm and 180 mm. The length of the second portion 62 can typically be between 250 mm and 350 mm.
[0065] The articulated assembly includes a mounting plate 4 for attaching to the backrest frame. The plate is a thick plate fixed to the side flange 92 of the backrest. In the illustrated example, the plate has holes 45 opposite corresponding holes in the side flange of the backrest. Bolts 14 secure the plate 4 to the side flange 92 of the backrest.
[0066] The stirrup 5 is a two-winged part 51, 52 extending on either side of a central angled part 50 in the shape of a portion of a cylinder. It is obtained from a curved metal plate.
[0067] The two wings 51,52 extend in respective planes which are angularly separated by an angular gap typically between 50° and 60° in the illustrated example.
[0068] The bracket is welded to the plate by means of weld beads S visible to the [Fig.2],
[0069] A tubular bearing 8 is fixed to the yoke in the angled area 50 of the yoke. The tubular bearing 8 is centered on Y2.
[0070] The articulated assembly includes a bracket 5 welded to the plate 4. The bracket contributes to the indexing of each of the first and second positions. The bracket forms an angular stop for the cam, which will now be described. The first wing 51 forms a stop for the cam and determines the first position P1 of the armrest. The second wing 52 forms a stop for the cam and determines the second position P2 of the armrest.
[0071] It is noted that the plate 4, the stirrup 5 and the tubular bearing 8 are integral with the lateral flange of the backrest.
[0072] In addition, a shaft 7 is provided, rotatably mounted in the tubular bearing 8. This shaft 7 is rotationally fixed to the armrest frame 60.
[0073] A cam 2 is fixed to one end of the shaft; the cam 2 rotates with the shaft 7. The shaft 7 rotates with the cam and with the armrest. The cam includes a local projection 20 that extends radially outwards from the rest of the cam's periphery.
[0074] The shaft 7 includes a first end 71 on which the cam is mounted.
[0075] On the opposite end 72 of the shaft is fixed the armrest frame 60.
[0076] A flat shape 75 with one or two flats is used to ensure the transmission of torque between on the one hand the shaft 7 and the armrest 6 and on the other hand between the shaft 7 and the cam 2.
[0077] The tubular bearing typically has a length between 50 mm and 80 mm to support the forces of the cantilevered armrest mounting. The shaft 7 is slightly longer, typically protruding 2 to 3 mm on the cam side and 3 to 4 mm on the armrest frame side. These dimensions are not, of course, limiting.
[0078] On the stationary part, i.e. fixed on the plate and / or on the bracket, an elastic element 3 is provided for cooperating with the cam in order to move the armrest towards either the first position or the second position.
[0079] In the example illustrated in Figures 5, 8, 9, and 10, the elastic element 3 is a leaf spring operating in bending. The leaf spring comprises a mounting portion 30 that is fixed rigidly to the second wing 52 of the caliper, and a cam-following portion, denoted 31, that bears permanently on the cam. In the illustrated example, the mounting portion 30 is secured by at least two bolts 35.
[0080] It should be noted that [Fig.5] illustrates on the same sketch three different positions of the leaf spring 3 and several positions of the cam 2.
[0081] In the example illustrated in [Fig. 13], the elastic element is in the form of a helical spring working in compression. The helical spring is connected on one side to a fixed attachment point 33, which is rigidly connected to the bracket 5. The helical spring is connected on the other side to a movable attachment point 34 mounted on the cam.
[0082] The helical spring is shown as a solid line in the maximum compression position (unstable position). The helical spring is shown as a dashed line in position 3a, corresponding to the first position of the armrest. The helical spring is also shown as a dashed line in position 3b, corresponding to the second position of the helical spring.
[0083] Figure 11 illustrates the deployment of the airbag. It can be seen that the volume occupied by the inflated bag does not interfere with the first position of the armrest, nor does it interfere with the second position of the armrest. Furthermore, the presence of the armrest does not hinder the deployment of the bag.
[0084] Still with reference to [Fig.1 1], a guard gap E2 is provided between the outer face 91 padding of the backrest and the armrest 6, along Y.
[0085] The clearance gap E2 is at least 3 mm. Placing a seat cover on the backrest does not fill this gap. Therefore, there is no contact between the armrest and the outer lateral face of the backrest; such contact could prevent the armrest from reaching the second position P2.
[0086] As already stated, the armrest 6 is movable over an angular stroke 0c between the first position P1 (angle 01) and the second position P2 (angle 02). As shown in [Fig. 10], the angular stroke includes a first angular range 0a where armrest 6 is returned by elastic member 3 to the first position PI, and a second angular range Ob where the armrest is returned by the elastic member to the second position P2.
[0087] Thanks to the arrangements described above, the first position PI of the armrest is mechanically stable and indexed, and the second position P2 is mechanically stable and indexed. Conversely, all intermediate positions between these two extreme positions are mechanically unstable.
[0088] Regarding the position located at the boundary between the two aforementioned angular ranges 0a, 0b, as illustrated in [Fig. 10], the movement of the motor vehicle induces vibrations that will necessarily be transmitted to the articulated assembly connecting the armrest to the backrest frame. These vibrations then cause the bracket to tilt to one side or the other, towards one of the extreme positions P1 or P2, most often towards the lowered position.
[0089] This gives the desired effect, namely that each of the first and second positions P1,P2 leaves free a volume necessary for the deployment of the airbag from the lateral area of the backrest as illustrated in [Fig. 11].
[0090] It is noted that the plate 4, the yoke 5, the tubular bearing 8, the shaft 7, and the elastic element 3 are preferably made of metal, steel, or a light alloy. The plate 4 and the yoke 5 are manufactured by cutting and bending a sheet of steel with a typical thickness of between 2 and 3 mm. The shaft 7 is a solid rod, and the tubular bearing 8 is obtained by sawing a conventional tubular profile.
Claims
Demands
1. A vehicle seat comprising a backrest frame (1) pivotally mounted on a seat frame, the vehicle seat being equipped with an airbag on one side, the vehicle seat being located in an orthogonal spatial frame comprising a vertical direction (Z), a longitudinal direction (X) and a transverse direction (Y), the vehicle seat comprising an armrest (6) connected via a hinged mounting (10) to the backrest frame (1), the armrest being located on the first side, the armrest being movable between a first position (P1) and a second position (P2), the armrest comprising a first portion (61) extending from the hinged mounting along a first extension direction (W1) and a second portion (62) extending the first portion along a second extension direction (W2) inclined angularly with respect to the first extension direction (W1), the first and second positions (P1,P2) each being mechanically stable and indexed, while all intermediate positions are generally mechanically unstable, the articulated assembly (10) comprising an elastic element (3) to return the armrest to the first or second position, each of the first and second positions leaving free a volume necessary for the deployment of the airbag from a lateral area of the backrest on the first side.
2. Vehicle seat according to claim 1, wherein the articulated assembly (10) is a pivoting joint, preferably with a transverse axis (Y2).
3. Vehicle seat according to claim 2, wherein the first position (PI) is angularly separated from the second position (P2) by an angular gap (0c) between 90° and 120°, preferably close to 110°.
4. Vehicle seat according to any one of claims 2 to 3, wherein an angular travel between the first position and the second position is provided, with a first angular range (0a) where the armrest (6) is returned by the elastic member (3) to the first position (PI), and a second angular range (0b) where the armrest is returned by the elastic member to the second position (P2).
5. Vehicle seat according to any one of claims 1 to 4, wherein the articulated assembly includes a plate (4) for attachment to the backrest frame.
6. Vehicle seat according to claim 5, wherein the articulated assembly includes a bracket (5) welded to the plate (4), the bracket contributing to the indexing of each of the first and second positions (P1,P2).
7. Vehicle seat according to any one of claims 1 to 6, wherein the articulated assembly comprises a shaft (7) integral with the armrest, the shaft being provided with a cam (2) cooperating with the elastic member formed as a spring cooperating with the cam.
8. Vehicle seat according to claim 6 and claim 7, wherein the shaft (7) is received in a tubular bearing (8) welded onto the bracket (5).
9. Vehicle seat according to claim 2, wherein a guard gap (E2) is provided along the transverse direction (Y) between the padding of the backrest and the armrest (6).
10. Vehicle comprising a seat according to any one of claims 1 to 9.