FR3148183A1 - tilting seat - Google Patents

Abstract

The invention relates to a seat comprising a seat, a backrest (20) extending along a main axis, a headrest (30) and means for mounting the headrest on the backrest which give the headrest rotational mobility relative to the backrest around an axis of rotation (A1) substantially parallel to said main axis. Abstract: Fig.2

Description

tilting seat Technical field of the invention

The present invention relates generally to the habitability of motor vehicles.

It relates more particularly to a seat comprising a seat, a backrest and a headrest.

It also concerns a motor vehicle comprising such a seat.

State of the art

A car has at least two seats, namely a driver's seat and a passenger seat.

It is known to use seats with backrests that can tilt backwards and forwards, allowing occupants to adjust the inclination of the backrests to ensure good driving comfort.

In some vehicles, this tilting may have sufficient travel for the backrest to be almost horizontal.

So, when the vehicle is stationary, the occupants can lie down and doze off or fall asleep.

Such a seat usually has a headrest. The primary function of the latter is to prevent the occupant of the seat from suffering a cervical trauma (or "whiplash") in the event of an impact from the rear. In order not to be too far from the head of the occupant of the seat during the impact, the headrest forms, in relation to the front face of the backrest, a bulge projecting forward.

The downside to this seat is that when the backrest is in the reclined position, the bulge formed by the headrest is in a position that is not ideal for the occupant to rest their head on.

Presentation of the invention

In order to overcome the aforementioned drawback of the state of the art, the present invention proposes a seat as defined in the introduction, comprising means for mounting the headrest on the backrest which give the headrest rotational mobility relative to the backrest around an axis of rotation substantially parallel to the main axis of the backrest.

Thus, thanks to the invention, it is possible to turn the headrest.

This rotation allows the seat occupant to place one or the other of the two faces of the headrest forward. If these two faces have different distances from the axis of rotation, rotating the headrest will therefore allow the size of the bulge formed by the headrest in front of the backrest to be varied.

This mobility of the headrest may also have other interests. Typically, the two sides of the headrest could have different coverings, which the user could choose by turning the headrest over or not.

Other advantageous and non-limiting characteristics of the seat according to the invention, taken individually or in all technically possible combinations, are as follows:
- the headrest comprises a frame covered by a lining which has two opposite main faces and the thickness of which at the centre of one of the main faces (measured radially relative to the axis of rotation) is different from the thickness at the centre of the other of the main faces (measured radially relative to the axis of rotation);
- said mounting means comprise an indexing system for blocking the rotation of the headrest around the axis of rotation in two stable positions;
- said mounting means comprise a cylindrical shaft substantially of revolution around the axis of rotation (for example cylindrical, or of section in the form of regular polygons with 30 sides) and a sleeve engaged on said shaft, and the indexing system comprises, hollowed out respectively in the sleeve or in said shaft, a cam path in which at least one protruding lug navigates on said shaft or the sleeve respectively;
- said cam path delimiting two stable reception cradles for said lug, the indexing system comprises means for returning said lug towards the cradles;
- said mounting means give the headrest translational mobility relative to the backrest along an axis substantially parallel to said main axis;
- the mounting means comprise a sheath and a slide adapted to slide in the sheath;
- said mounting means comprise means for blocking the translational mobility of the headrest relative to the backrest, which can be manually operated to release the translational mobility of the headrest relative to the backrest;
- the backrest is mounted so as to be movable relative to the seat between a position of use in which it is inclined relative to the seat and a lying position in which it extends in line with the seat.

The invention also provides a motor vehicle comprising a seat as mentioned above.

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

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

On the attached drawings:

is a schematic view of a seat according to the invention, shown in two distinct configurations;

is a schematic view of the seat of the , whose headrest is shown with four different orientations;

is a schematic view of the backrest and headrest frame of the , on which the fillings are shown in a semi-transparent manner;

is a schematic exploded perspective view of the frame of the headrest of the seat of the , and means of mounting this headrest on the backrest;

is an assembled schematic perspective view of the mounting means of the ;

is a view homologous to that of the , shown from a different angle;

is a schematic perspective view of the frame of the seat of the .

On the , a seat 1 is shown intended to be installed in the passenger compartment of a motor vehicle. This motor vehicle could be of any type. It could typically be a coach, a truck, a wagon, an airplane, etc. But preferably, it will be a car, the passenger compartment of such a car having in fact a reduced volume to which the seat 1 will be specially adapted.

Here, we will consider that this car has a driving position (including a steering wheel and a dashboard), a driver's seat located opposite the driving position, a passenger seat located next to the driver's seat, and one or more rear seats (armchairs and/or bench seats) located behind the driver and passenger seats. In other words, the seats are here distributed over two rows located one behind the other.

Seat 1 shown in the belongs to the front row: this is the driver's seat or the passenger seat.

As shown in the , this seat 1 comprises several components, including in particular a seat 10, a backrest 20 and a headrest 30.

As a preliminary point, it should be noted that in 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.

The terms “low” and “high” (or lower and “upper”) will be used interchangeably, with the lower part of an element designating the part of that element which is located on the floor side of the vehicle and the upper part designating the part of that element which is located on the roof side of the vehicle.

A “longitudinal axis” will be an 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.

A “transverse axis” will be an axis orthogonal to the longitudinal axes, extending horizontally when the vehicle is located on a horizontal road.

A “normal axis” will be an axis orthogonal to the aforementioned axes, extending vertically when the vehicle is located on a horizontal road.

We can also define the “main axis A0 of the file” (see ) as an axis belonging to the plane of symmetry of the backrest and extending from the lower side of the backrest to the upper side. This may for example be the axis which is on average closest to the front face of the backrest (for example according to the method of least squares) or the axis which is on average halfway between the front and rear faces of the backrest.

The seat 10, the backrest 20 and the headrest 30 each comprise at least one frame 11, 21, 31 (figures 3 and 7) on which is attached a trim 12, 22, 32 ( ), typically a piece of foam that has been expanded to the desired shape.

As shown in the , the backrest 20 is here mounted tilting relative to the seat 10 around a transverse axis, so that the seat 1 can be placed in a usage configuration (backrest inclined by less than 30° relative to the vertical) or in a lying configuration (backrest placed in the extension of the seat). The lying configuration is used when the occupant of the seat wishes to rest there. The usage configuration is used rather when the vehicle is moving. It will be noted that the terms "front", "rear", "top" and "bottom" will be used to designate sides of the components of the seat considering that the latter is in the usage position, facing the road.

As shown in the , the headrest 30 is mounted on the backrest with two degrees of mobility. It is thus adapted to slide along an axis substantially parallel to the main axis A0 of the backrest (to within 30 degrees). It is also adapted to pivot about an axis substantially parallel to the main axis A0 of the backrest (to within 30 degrees).

The headrest is adapted to pivot through a travel of at least 180°, so that it can be turned around.

Its upholstery 32 then has two main faces 321, 322 located opposite each other, which can each be oriented towards the front of the backrest so that the head of the occupant of the seat rests on it.

These two main faces 321, 322 are substantially planar. They thus extend in substantially parallel planes, which are spaced from the axis of rotation A1 by different distances. More precisely, the centers of these faces are spaced from the axis of rotation A1 by different distances d1, d2.

The first face 321, when facing forward, forms a bulge projecting forward relative to the front face of the backrest (it thus forms a step at the junction between the backrest and the headrest). This face of the trim 32 is therefore facing forward when the backrest is in the use position.

The second face 322, when it is turned towards the front of the backrest, extends substantially in the extension of this backrest. This face of the upholstery 32 is therefore oriented towards the front when the backrest is in the lying configuration, so that the headrest does not hinder the occupant when sleeping.

As also shown by the , the headrest 30, when in the low position, is housed in a recess 23 in the upper edge of the backrest 20. It can therefore be used in this position by a person of small size. On the other hand, it is designed to move away from this recess upwards, to adapt to tall people.

In this embodiment, the headrest trim 32 has an edge having straight upper and lower sides, and V-shaped lateral sides that point in opposite directions. Then, the notch 23 provided in the backrest 20 has a corresponding shape, with a straight lower side and two straight lateral edges inclined relative to each other.

The mounting means 40 of the headrest 30 on the backrest 20 allowing the headrest 30 to benefit from these two mobilities could take various forms.

Figures 3 et seq. show an embodiment of these mounting means.

Before describing them, we will note, with reference to the , that the frame 21 of the backrest 20 here comprises two parallel sides 211, a lower crosspiece 213 (visible only on the ) and an upper connecting element 212, these four elements together forming a frame supporting the upholstery 22 of the backrest 20.

The frame 31 of the headrest 30 is then mounted movably on this frame 21 of the backrest.

As shown in Figures 3 and 4, the frame 31 is here in the form of a metal rod folded to form a sort of loop whose outline follows that of the trim 32. The two ends of this rod are here welded to a tubular sleeve 33.

To provide the headrest 30 with up-and-down sliding mobility, the mounting means 40 comprise a sheath 43 which is fixed to the upper joining element 212 of the frame 21 of the backrest 20, and a rod 44 slidably mounted in this sheath 43.

Here, the sheath 43 is formed of two parts 43A, 43B fitted one on top of the other and fixed together, but as a variant, it could be made in a single piece.

One of these parts 43B is welded to the upper joining element 212 of the frame 21 of the backrest 20. The other of these parts 43B, which delimits the passage for the rod 44, is fixed in the first part 43B. The advantage of using two separate parts is to make it possible to separate the manufacture of the backrest and the headrest, the backrest being assembled with the first part 43B when the headrest is assembled elsewhere with the first part 43A.

The sheath 43 is profiled in the sense that it delimits a passage for the rod 44 of uniform cross section along its length. This section is not cylindrical in revolution so that the rotation of the headrest is not ensured by the sheath: the two mobilities are in fact well separated.

The straight section of the passage delimited by this sheath 43 is here of substantially rectangular shape.

The cross section of the rod 44 has an identical shape, in negative. An operating clearance is of course provided so that the rod 44 can slide freely in this sheath 43. This clearance remains minimal so that the rod 44 remains well guided in translation by the sheath 43.

In the embodiment illustrated in Figures 3 and 4, it can be seen that the rod 44 is not perfectly straight, but is curved around a transverse axis. The same is true of the sheath 43. The mobility of the headrest 30 is therefore not exactly a translation mobility: we will speak of pseudo-translation. This curvature is adapted to the curvature of the back of the occupant of the seat: it is such that the headrest, once adjusted in height according to the size of the occupant, remains at a constant distance from the occupant's head (whatever the size of the latter).

The rod 44 is perfectly profiled, except that it is bordered at its upper end by an external edge 441 which forms a stop making it possible to limit the travel of the rod 44 in the sheath 43 downwards. No stop is provided at the bottom of the rod, which makes it possible to completely remove the headrest from the backrest.

To prevent the headrest 30 from sliding naturally into the low position under the effect of gravity and not being able to remain in another position, means are provided for blocking the sliding of the rod 44 in its sheath 43.

These locking means could be in the form of a friction braking system. However, here they are rather in the form of a notching system.

In practice, a collar 45 is fixed to the upper end of the sheath 43 (it could be fixed directly to the frame 21 of the backrest 20). This collar 45 comprises an annular body 451 which delimits an opening for the passage of the rod 44. It also comprises a lug 452 mounted movably on the body 451 between a position deployed towards the inside of the opening and a position retracted inside the body 451.

In correspondence, the rod 44 carries at least one notch in which the lug can engage when the latter is in the deployed position, in order to block the sliding mobility of the rod 44 in the sheath 43. It may be provided that the rod 44 comprises several notches distributed along its length, so as to be able to block the headrest 30 at different heights relative to the backrest 20. The number of notches will preferably be greater than or equal to three. It could typically be five.

Manual operating means are then provided to release this sliding movement if necessary to adjust the height of the headrest 30.

Here, the collar 45 comprises a lever 453 which, when pressed, allows the lug 452 to be pushed back into the retracted position in the body 451, so that it retracts and leaves the rod 44 free to slide. A return means such as a spring is provided to automatically return the lug 452 and the lever 453 to the deployed position.

It may be noted that in the illustrated embodiment, the lug 452 and the lever 453 form a single, sliding part mounted in the body 451 of the collar 45, the lug extending into one branch of the body 451 while the lever 453 extends into the opposite branch so as to be accessible from the outside of the body 451. The body 451, which is preferably made of plastic, is snapped onto the upper end of the 43.

To provide the headrest 30 with pivoting mobility around the axis of rotation A1, the mounting means 40 comprise a substantially cylindrical shaft 41 of revolution around the axis of rotation A1, on which the sleeve 33 (which supports the rod of the frame 31 of the headrest 30) can freely pivot.

Here, the sleeve 33 delimits a substantially cylindrical hole of revolution around the axis of rotation A1 and of diameter substantially equal to that of the shaft 41, excluding the sliding clearance. Thus, the sleeve 33 can be mounted on the shaft 41 and pivot relative to the latter around the axis of rotation A1.

The shaft 41 comprises, at its lower end, a base 411 in the form of a flange by which it is fixed (for example by screwing) to the outer edge 441 of the rod 44.

The mounting means 40 of the headrest 30 on the backrest 20 then comprise an indexing system 49 making it possible to block the rotation of the headrest 30 around the axis of rotation A1 in two stable positions. The objective is that only the two main faces 321, 322 of the trim 32 of the headrest can be placed forward, facing the road.

Here, as shown in Figures 5 and 6, these indexing means 49 comprise a cam system.

More precisely, the inner face of the sleeve 33 delimits a cam path 340 in which a lateral pin 410 fixed to the shaft 41 can navigate.

The lateral pin 410 has a cylindrical shape of revolution around an axis perpendicular to the axis of rotation A1. It thus extends radially relative to the shaft 41. It is here located on the side of the upper end of this shaft.

The cam path 34 is a groove provided in a hollow in the inner face of the sleeve 33. This groove has a width equal, apart from the clearance, to the diameter of the side pin 410, and a depth greater than the height of this pin.

It has a particular shape, with first of all a first section 341 which opens onto the lower end of the socket 33 ( ). This first section 341 has, from this lower end, a first part which extends here parallel to the axis of rotation A1 and a second part which is curved towards a second section 342 of the cam path 34.

The first section allows the bushing 33 to be mounted on the shaft 41, and the side pin 410 to be guided to the second section. It should be noted that the side pin is no longer supposed to come out of this second section once the bushing 33 is mounted on the shaft 41.

The second section 342 generally has a U shape, with two high ends 340 (see figures 5 and 6).

The first section 341 then opens into an arm of the U, halfway up.

The upper ends 340 of the second section 342 form two cradles for receiving the side pin 410, which guarantee two stable positions for the headrest 30.

For this, the indexing means 40 comprise a means for returning the sleeve 33 downwards, which make it possible to return the lateral pin 410 to the bottom of one or other of the cradles. These return means are here in the form of a traction spring 42, a lower end of which is fixed to the base 411 of the shaft 41, and the other end of which is fixed to a rod 330 provided at the upper end of the sleeve 33 and extending along one of its diameters.

Thus, when the user wishes to return the headrest 30, he must lift and pivot the latter (countering the force exerted by the tension spring 42), so that the lateral pin 410 leaves the cradle associated with a first stable position and navigates along the second section 342 of the cam path 340. Once the pin has navigated over more than half of this section, the user can release the headrest 30. Indeed, the tension spring then makes it possible to force the pin to navigate to the cradle associated with the second stable position. Thus, the headrest can finish its rotation at 180°.

The remainder of seat 1 can now be described, with reference to figures 1 and 7.

Here, the seat 10 of the seat 1 comprises two distinct parts, namely a peripheral part and a central part mounted so as to be able to rotate relative to the peripheral part, at the centre of the latter.

The backrest 20 is fixed to the central part. It is therefore possible to pivot the backrest 20 and the central part of the seat 10 around a normal axis A2, to place the seat facing the nearest door or to turn the seat to face the rear passengers.

As shown in the , the peripheral part 121 of the upholstery 12 of the seat 10 has an outer edge of rectangular shape (with rounded corners) and a central opening. The central part 122 of this upholstery has a corresponding outer edge of circular shape. Thus, the upholstery of the seat 10 has a standard shape externally, except that it is formed in two parts.

The peripheral part of the seat 10 is designed to remain fixed when the central part of the seat 10 and the backrest 20 pivot.

As the , the frame of the peripheral part of the seat 10 comprises two lateral flanks 110, connected together by connecting arms 111, 112 and on which the upholstery is attached. These flanks 110 are here in the form of substantially flat plates, oriented vertically and longitudinally.

Seat 1 is designed to be able to slide relative to the floor of the motor vehicle, from front to rear (along the longitudinal axis A3).

The frame therefore comprises two slides 113 each formed by a movable rail placed under the lower edge of one of the two sides 110 and a fixed rail comprising means for fixing to the floor of the vehicle (in this case, these are means for screwing to the floor). The movable rails are then shaped to be able to slide freely in the fixed rails. Means are also provided for blocking the sliding of the movable rails relative to the fixed rails (these may for example be notches carried by the movable rails and adapted to engage in notches in the fixed rails), and release means adapted to actuate the blocking means to release the sliding of the movable rails relative to the fixed rails (here, these release means are in the form of a manually operable rudder 113A).

The seat 10 is also designed to be able to rise or fall relative to the floor of the motor vehicle (along the normal axis A2).

The frame of the peripheral part comprises for this purpose two pairs of connecting rods (not visible) each articulated, on one side, on one of the movable rails and, on the other, on one of the two flanks 110. The flanks 110 can thus have a joint rotary translation movement around two transverse axes. Means are also provided for blocking the pivoting of the connecting rods, and release means adapted to maneuver the blocking means to release the pivoting of the connecting rods.

The central part of the frame 11 of the seat 10 comprises a base 118 on which the central part of the seat upholstery 12 is attached. This base 118 is here formed by a tube folded so as to form a sort of ring in a horizontal plane, around a normal axis A2.

Means are further provided for mounting the central part on the peripheral part of the seat frame, allowing these two parts to pivot relative to each other around the normal axis A2.

Preferably, the pivoting is combined with a translation along this normal axis A2, so that the movement of the central part relative to the peripheral part is not circular but helical around the normal axis A2.

Thus, when the central part pivots from its position of use facing the road to its side position facing the door or to its reversed position facing the rear passengers, it also rises. This elevation of the central part facilitates the user's entry into and exit from the vehicle.

To ensure this helical movement, the peripheral part of the frame of the seat 10 comprises a tubular support 118A which is fixed to the sides 110, between them, in a central position. This tubular support 118A has a cylindrical external face of revolution around the normal axis A2. Three helical grooves 118B are provided in hollow in this external face.

The central part of the seat frame comprises three corresponding feet which extend from the base 118, downwards and which carry at their free ends rollers mounted rotatably on these feet (not visible in the figures). These rollers are each engaged in one of the grooves 118B.

Thus, when a torque is exerted on the central part of the seat, these rollers roll in the grooves 118B which allows the central part to pivot in a helical movement.

Here, these grooves 118B extend over an angular sector of approximately 180°, so that the central part of the seat can pivot from its position of use facing the road to its reversed position facing the rear seats.

It should be noted that they could alternatively extend over a smaller angular sector, for example approximately 90°, so that the seat 1 can only pivot from its position of use facing the road to its side position, facing the door. This is particularly the case for the driver's seat which cannot necessarily be turned 180° due to the presence of the steering wheel (on which the backrest 20 may come into contact).

Locking means are also provided to block or release the rotational mobility of the central part relative to the peripheral part of the seat. A lever arranged on the backrest may, using a cable, allow the user to operate these locking means to release the rotation of the central part of the seat if necessary.

The frame 21 of the backrest is mounted on the base 118 of the central part of the frame 11 of the seat 10 by means of a connecting arm 50 which passes between the upholstery of the peripheral part and the upholstery of the central part of the seat 10.

This connecting arm 50 is articulated both on the base 118 and on the frame 21 of the backrest 20.

Thus, a first articulation is provided for making a pivot connection between the connecting arm 50 and the lower crosspiece 213 of the frame 21 of the backrest 20. This first articulation makes it possible to adjust the inclination of the backrest. Locking means make it possible to lock the articulation, and operating means make it possible to release this articulation if necessary to adjust the inclination of the backrest. A lever 25 arranged on the backrest may allow the user to actuate these operating means.

A second articulation makes it possible to create a pivot connection between the connecting arm 50 and the base 118 of the central part of the frame 11 of the seat 10. This second articulation makes it possible to tilt the backrest 20 backwards, in line with the seat (in the lying configuration), so that the occupant can lie down on his seat 1. Locking means make it possible to lock the articulation, and operating means make it possible to release this articulation if necessary to lay down the backrest or return it to the position of use. A lever arranged on the backrest may, using a cable, allow the user to actuate these operating means.

Claims (10)

Seat (1) comprising a seat (10), a backrest (20) and a headrest (30), the backrest (20) extending along a main axis (A0) between the seat (10) and the headrest (30), characterized in that it comprises means (40) for mounting the headrest (30) on the backrest (20) which give the headrest (30) rotational mobility relative to the backrest (20) around an axis of rotation (A1) substantially parallel to said main axis (A0). Seat (1) according to claim 1, in which the headrest (30) comprises a frame (31) covered by a lining (32) which has two opposite main faces (321, 322) and the thickness of which at the center of one of the main faces (321) is different from the thickness at the center of the other of the main faces (322). Seat (1) according to claim 1 or 2, wherein said mounting means (40) comprise an indexing system (49) making it possible to block the rotation of the headrest (30) around the axis of rotation (A1) in two stable positions. Seat (1) according to claim 3, in which said mounting means (40) comprise a shaft (41) substantially cylindrical in revolution around the axis of rotation (A1) and a sleeve (32) engaged on said shaft (41), and the indexing system (49) comprises, hollowed out respectively in the sleeve (32) or in said shaft (41), a cam path (34) in which at least one lug (410) protrudes from respectively said shaft (41) or the sleeve (32). Seat (1) according to claim 4, in which, said cam path (34) delimiting two cradles (340) for stable reception of said lug (410), the indexing system (49) comprises means (42) for returning said lug (410) towards the cradles (340). Seat (1) according to one of claims 1 to 5, in which said mounting means (40) give the headrest (30) translational mobility relative to the backrest (20) along an axis substantially parallel to said main axis (A0). Seat (1) according to claim 6, in which the mounting means (40) comprise a sheath (43) and a slide (44) adapted to slide in the sheath (43). Seat (1) according to claim 6 or 7, wherein said mounting means (40) comprise means (45) for blocking the translational mobility of the headrest (30) relative to the backrest (20), manually operable to release the translational mobility of the headrest (30) relative to the backrest (20). Seat (1) according to one of claims 1 to 8, in which the backrest (20) is mounted to move relative to the seat (10) between a position of use in which it is inclined relative to the seat (10) and a lying position in which it extends in line with the seat (10). Motor vehicle characterized in that it comprises a seat (1) according to one of claims 1 to 9.