WO2005051132A1

WO2005051132A1 - Automatically positioned articulated seat

Info

Publication number: WO2005051132A1
Application number: PCT/FR2004/002952
Authority: WO
Inventors: Didier Monard
Original assignee: Didier Monard
Priority date: 2003-11-20
Filing date: 2004-11-18
Publication date: 2005-06-09
Also published as: FR2862500A1

Abstract

The articulated seat (1) comprises a leg (2), a seat base (5), a seat back (6), means for adjusting the height and inclination of the seat base (5) and back (6) and a U-shaped arch (3) which is fixed to the leg (2) and which comprises two side rims (4) between which the seat base (5) is disposed. The adjusting means comprise two linking devices (7) which connect the seat base (5) and the seat back (6) and which are mounted in such a way that they can freely rotate about two horizontal axes of rotation which are located at the free ends of the side rims (4) of the arch (3) and which define a common axis of rotation (8). Each linking device (7) comprises a sliding axis (11) which is coupled to the corresponding axis of rotation and which is substantially perpendicular to the axis of rotation, such that the center of gravity of the unit, formed by the seat base (5), the seat back (6), the linking devices (7) and a user, is automatically positioned at the level of the common axis of rotation.

Description

Articulated seat with automatic positioning

Technical field of the invention

The invention relates to an articulated seat comprising: a foot, a seat, a backrest, a U-shaped arch, fixed on the foot and comprising two lateral branches between which the seat is disposed, two connecting devices, connecting the seat and backrest, and pivotally mounted relative to the arch around an axis of rotation, so that the center of gravity of the seat is automatically positioned in the vicinity of the axis of rotation when the user s sits on the seat.

State of the art

A seat is commonly composed of a seat and a backrest delimiting between them a space for receiving the body of a user. Certain articulated seats for relaxation allow the angle of the backrest to be varied relative to the seat, in order to adapt it to the comfort sought by the user. Commonly, the seat and the backrest are pivotally pivoted relative to one another. Easily reversible immobilization means make it possible to maintain the seat and / or the backrest in different inclinations desired by the user, depending on the position in which if he wishes to be supported by the seat. In general, at least one of the elements is integral with a chassis, to give the elements relative mobility with respect to each other. There have also been proposed articulated office seats with a seat, mounted, possibly in rotation, on a foot, a backrest which swivels relative to the seat, and locking means for locking the backrest in a desired position. Typically, the height of the seat is adjustable relative to the ground, regardless of the inclination of the backrest relative to the seat, and the assembly is blocked by independent locking means.

However, these articulated seats cause problems concerning, on the one hand, the modification of the angle delimited by the seat and the backrest and, on the other hand, the blocking in a determined position. Such a change in angle can be restrictive, both with regard to the operation aimed at adjusting the amplitude of this angle (problem of pressure exerted by the back), as with regard to the operation consisting in immobilizing the elements then mobile (compulsory and tedious locking).

It has also been proposed articulated seats optimizing the positioning of the user on the seat. Document EP-A-1327401 describes an articulated seat, with a seat and a back mounted rotatably about a general pivot axis, capable of sliding on convex sliding surfaces integral with the frame of the seat. Document EP-A-0515120 also describes an articulated seat with a general pivot axis which can take several positions thanks to notches. However, for these two seats, the pivot axis is movable, which causes stability problems, and the adjustment of the position of the user does not take into account the weight of the user. Subject of the invention

The object of the invention is to provide an articulated seat which does not have these drawbacks and, in particular, an articulated seat optimizing the positioning of a user without requiring the use of locking means.

According to the invention, this object is achieved by a seat according to the appended claims and, more particularly, by the fact that: the axis of rotation comprises two axes, integral with the free ends of the branches of the arch, each connecting device comprises sliding means along a sliding axis integral with the corresponding axis of rotation and substantially perpendicular to said axis of rotation.

Brief description of the drawings

Other advantages and characteristics will emerge more clearly from the description which follows of a particular embodiment of the invention given by way of nonlimiting example and represented in the appended drawings, in which:

Figure 1 is a schematic front view of an embodiment of an articulated seat according to the invention. FIG. 2 is a partial section view of a device for connecting a seat according to FIG. 1.

FIG. 3 is a schematic view in partial section of one end of the support frame of a seat backrest according to FIG. 1. FIG. 4 is a schematic sectional view of the free end of a lateral branch of the arch of a seat according to FIG. 1.

Figures 5 to 7 show, in schematic partial section, the seat according to Figure 1 in three characteristic positions, respectively in the initial position, in the end position A and in the end position B.

Description of the particular embodiment

In FIG. 1, the articulated seat 1 comprises a foot 2, on which is fixed a U-shaped arch 3, comprising two lateral branches 4a and 4b. The arch 3 constitutes the supporting frame of a seat 5, located between the branches 4a and 4b, and of a backrest 6. The seat 5 and the backrest 6 are connected together by two identical connecting devices 7a and 7b and symmetrical with respect to the seat 5. The connecting devices 7a and 7b constitute means for adjusting the inclination of the seat 5 relative to the backrest 6. The connecting devices 7a and 7b are mounted in free rotation around two axes of rotation 8a and 8b, located at the free ends of the lateral branches 4a and 4b of the arch 3. The axes of rotation 8a and 8b define a common axis of rotation 8 representing the main axis of rotation of the seat 1 in use. The seat 5 and the backrest 6 thus constitute, with the connection devices 7a and 7b, a tilting assembly pivotally mounted relative to the arch 3, around this common axis of rotation 8.

The backrest 6 preferably includes, at its upper end, a headrest 9, the height and the inclination of which can be adjustable relative to the backrest 6.

The arch 3 can be mounted for free rotation about the vertical axis of the leg 2, to allow rotation up to 360 ° of the seat 1. The arch 3 can advantageously include armrests 10a and 10b, preferably adjustable in height, respectively integral with the free ends of the lateral branches 4a and 4b.

The connecting devices 7a and 7b being identical, they comprise the same constituent elements and work inseparably to obtain the desired natural positioning. Thus, in the description which follows, - the references are made relative to the connection device 7a, but the description applies in the same way to the connection device 7b.

As shown in Figure 2, the connecting device 7a comprises sliding means along a sliding axis 11a, which is integral with the axis of rotation 8a corresponding and substantially perpendicular to said axis of rotation 8a. These sliding means represent a first adjustment means allowing the center of gravity of an assembly, constituted by the tilting assembly (the seat 5, the backrest 6, the connecting devices 7 and the user), to position themselves automatically at the common axis of rotation 8.

To this end, the connecting device 7a preferably comprises a hollow cylindrical casing 12a intended to slide along the sliding axis 11a corresponding therethrough. In the particular embodiment shown, an internal block 30a, crossed by the sliding axis 11a, is disposed in the upper part of the cylindrical casing 12a of which it is integral. A return spring 13a, arranged at least partially in the lower part of the casing 12a, has two ends 14a and 15a, respectively integral with the lower end of the lower block 30a and the lower end of the sliding axis 11a. The compression of the spring 13a essentially depends on the weight, more or less important, of the user. The articulated seat 1 thus makes it possible to obtain a natural tilting movement of a user, by an automatic positioning of the center of gravity of the user at the level of a main axis of rotation of the articulated seat, thanks to the connecting devices 7 connecting the seat 5 and the back 6, which are mounted in free rotation on the chassis acting as a fixed support and which slide along the sliding axes 11.

A support frame 16a of the seat 5 is preferably mounted in free rotation relative to the connecting device 7a about a pivot axis 17a of the seat 5. This pivot axis 17a constitutes a second means of adjustment for user positioning. It allows, on the one hand, the inclination of the seat 5 relative to the connecting device 7a and, on the other hand, to more finely adjust the positioning of the user's center of gravity. A support frame 18a of the backrest 6 is preferably mounted in free rotation relative to the connecting device 7a around a pivot axis 19a of the backrest 6. This pivot axis 19a constitutes a third adjustment means for positioning of the user. It allows the backrest 6 to be inclined relative to the connecting device 7a and completes the adjustment of the position of the user's center of gravity.

The end of the support frame 18a, associated with the pivot axis 19a of the backrest 6, passes, for example with play, through a transverse orifice 31a formed in the internal block 30a and the casing 12a. This end of the support frame 18a is preferably shaped like a fork with two teeth, crossed by the pivot axis 19a and delimiting, between the teeth, a guide path for the corresponding sliding axis 11a (FIG. 3). This specific design makes it possible to couple the two movements, namely the sliding of the connecting device 7a and the rotation of the backrest 6, generating a phenomenon of resistance to inclination proportional to the weight of the user. This phenomenon of resistance to tilting is due to the particular design of the support frame 18a with its fork-shaped end which makes it possible to guide the sliding axis 1 1 a inside the hollow cylindrical envelope. 12a. The different adjustment means described above, namely the sliding of the connecting device 7a, the pivoting of the seat 5 and the pivoting of the backrest 6, are both independent and coupled to obtain the desired natural positioning of the center of user severity.

The connecting device 7a also includes a first lever 20a, integral with the axis of rotation 8a, perpendicular to the latter (Figures 2 and 4) and intended to cooperate with first end of travel stops 21a and 22a. These are integral with the arch 3 (FIG. 4), and correspond respectively to an end of travel position A and to an end of travel position B of the articulated seat 1 in tilting. The end position A corresponds to a maximum tilting forward according to arrow F2 (Figure 6) and the end position B corresponds to a maximum tilting back according to arrow F3 (Figure 7). The stops 21a and 22a are preferably incorporated in the lateral branch 4a of the arch 3 (FIG. 4), which is then shaped as a receiving cage for the lever 20a, to allow a pivoting amplitude of the lever

20a of the order of 15 °.

The connecting device 7a also includes a second lever 23a (FIG. 2), integral with the pivot axis 17a of the seat 5, perpendicular to it and intended to cooperate with second end-of-travel stops 24a and 25a .

These are integral with the connection device 7a, and correspond respectively to the end position A and the end position B of the articulated seat 1 in tilting. The stops 24a and 25a are preferably formed by walls of the connecting device 7a. In Figure 2, the stop 24a protrudes inwards from a support piece 32a, triangular, integral with the casing 12a of the connecting device 7a to form with an adjacent wall of the support piece 32a an acute angle at the pivot axis 17a of the seat 5 (FIG. 2), authorizing an amplitude of pivoting of the lever 23a of the order of 10 ° to 15 °.

Damping elements 26a, 27a (Figure 4) and 28a, 29a (Figure 2), respectively fixed to the end stops 21a, 22a and 24a, 25a, are arranged, respectively on the lateral branch 4a of the arch 3 and on the connecting device 7a, more particularly on the support piece 32a, in order to damp the rotation, respectively of the levers 20a and 23a, in end positions A and B. The damping elements 26a, 27a, 28a and 29a are preferably rubber blocks, glued to the corresponding end-of-travel stops 21a, 22a, 24a and 25a, to protect them and dampen the pivoting of the levers 20a and 23a.

As shown in fig 4, to obtain an optimal damping effect, the rubber block 26a is shaped so as to fill the empty space between the end stop 21a and the lever 20a, while the block rubber 27a is shaped so as to fill the empty space between the end stop 22a and the lever 20a. Similarly, as shown in FIG. 2, the rubber block 28a is shaped so as to fill the empty space between the stop 24a and the lever 23a, while the rubber block 29a is shaped so as to fill the space vacuum between the stop 25a and the lever 23a.

As shown in FIG. 2, the pivot axes 17a of the seat 5 and 19a of the backrest 6 are preferably both articulated on the support part 32a, disposed between the casing 12a and the seat 5. Three characteristic positions of the articulated seat 1 will be described in more detail with regard to Figures 5 to 7. In Figure 5, the seat 1 is empty, in the initial position. In this position, the levers 20a, 20b and 23a, 23b are in their initial position, and the return springs 13a, 13b are stressed in compression. When the user installs himself on the seat 5, a first adjustment is carried out naturally by sliding downwards, along arrow F1, connecting devices 7a, 7b to compensate for the weight of the user. Depending on the position of the user, the support frames 18a, 18b of the backrest 6 pivot around the pivot axes 19a, 19b, while the seat 5 pivots around the pivot axes 17a, 17b. The seat 5 and the backrest 6 can take any intermediate position, between the end positions A and B. The connecting devices 7a, 7b having slid along the sliding axes 11a, 11b, the cylindrical casings hollow 12a, 12b stress in compression the return springs 13a, 13b, which are then in a compressed position, which causes a high resistance to tilting.

In FIG. 6, the seat 1 is in the first end-of-travel position A, representing the limit tilting forwards according to the arrow F2. In this position, the positions of the seat 5 and of the backrest 6 naturally adapt to the tilting of the user and the angle then formed by the seat 5 and the backrest 6 is as acute as possible, of the order 90 °. The levers 20a, 20b come into contact with the damping elements 26a, 26b of the stops 21a, 21b of the arch 3, while the levers 23a, 23b come into contact with the damping elements 28a, 28b of the stops 24a, 24b of the connecting devices 7a, 7b. The support frames 16a, 16b of the seat 5 have pivoted around the pivot axes 17a, 17b to maintain an optimal inclination between the seat 5 and the backrest 6 and to adjust the adjustment of the positioning of the center of gravity of the user. The support frames 18a, 18b of the backrest 6 have also pivoted, eliminating the initial play between the support frames 18a, 18b and the internal blocks 30a, 30b at the upper part of the transverse orifices 31a, 31b, and then urge the return springs 13a, 13b. These are then in a stretched position, which causes a strong resistance to tilting.

In FIG. 7, the seat 1 is in the second end-of-travel position B, representing the limit tilting towards the rear according to arrow F3. In this position, the seat 5 and the backrest 6 naturally adapt to the tilting of the user and the angle then formed by the seat 5 and the backrest 6 is as obtuse as possible of the order of 145 °. The levers 20a, 20b come into contact with the damping elements 27a, 27b of the stops 22a, 22b of the arch 3, while the levers 23a, 23b come into contact with the damping elements 29a, 29b of the stops 25a , 25b. The support frames 16a, 16b of the seat 5 have pivoted around the pivot axes 17a, 17b to maintain an optimal inclination between the seat 5 and the backrest 6 and to adjust the adjustment of the positioning of the center of gravity again. the user. The support frames 18a, 18b of the backrest 6 have pivoted about the pivot axes 19a, 19b. The initial clearance between the support frames 18a, 18b and the internal blocks 30a, 30b is then eliminated at the bottom of the transverse orifices 31a, 31b. This increases the compression effect exerted on the return springs

13a, 13b and, consequently, the resistance to tilting.

The natural positioning of the user's center of gravity on the articulated seat 1 is therefore dependent on the weight of the user. The higher the weight, the more the connecting devices 7a and 7b create resistance to tilting. The user's center of gravity is always substantially aligned with the main axis of rotation of the seat 1 and the user can tilt around this axis while maintaining an optimal position, without having to lock the components of the seat. 1. The user retains a natural position on the seat 1, throughout the tilting, thanks to the axis of rotation 8, to the pivot axes 17 of the seat 5, to the pivot axes 19 of the backrest 6 and to the sliding axes 11 of the connecting devices 7, which provide, at any time, an adjustment of the positioning of the user's center of gravity relative to the articulated seat 1.

The articulated seat 1 described above makes it possible, in particular, to improve the tilting of the seat 1 and the comfort of the user, thanks to the automatic positioning of the center of gravity of the user at the level of the axis 8 of main rotation. of the seat 1. Furthermore, the user does not experience back problems due to the forced positioning of the seat 5 relative to the backrest 6 and does not use locking means to lock the seat 1 in the desired position. The comfort of the user is optimum, because it pivots at its axis of gravity.

The invention is not limited to the embodiment described above. In particular, each connecting device 7 is made of suitable materials having the qualities of mechanical resistance required, and each constituent element of the seat 1 in contact with the user (seat 5, backrest 6, headrest 9, armrests 10) is advantageously formed with foam padding to improve comfort. Similarly, the seat 5 can be mounted in free rotation around the support frames 16 to obtain an additional automatic adjustment of the position of the user on the seat 5. Also, the return spring 13a can be replaced by any another suitable means of return, for example a blade or a jack.

The articulated seat 1 according to the invention is used particularly as an office seat or as a seat for relaxation.

Claims

claims

1. Articulated seat (1) comprising: - a foot (2), a seat (5), a backrest (6), a U-shaped arch (3), fixed to the foot (2) and comprising two lateral branches (4a, 4b) between which is placed the seat (5), two connecting devices (7), connecting the seat (5) and the backrest (6), and pivotally mounted relative to the arch (3 ) around an axis of rotation (8), so that the center of gravity of the seat (1) is automatically positioned in the vicinity of the axis of rotation (8) when the user sits on the seat (1), seat characterized in that: the axis of rotation (8) comprises two axes (8a, 8b), integral with the free ends of the branches (4a, 4b) of the arch (3), each connecting device (7) comprises sliding means along a sliding axis (11) integral with the axis of rotation (8a, 8b) corresponding and substantially perpendicular to said axis of rotation (8a, 8b).

2. Seat according to claim 1, characterized in that a support frame (16) of the seat (5) is mounted in free rotation relative to the connecting devices (7) about a pivot axis (17 ) of the seat (5).

3. Seat according to claim 2, characterized in that a support frame (18) of the backrest (6) is mounted in free rotation relative to the connecting devices (7) around a pivot axis (19) of the backrest (6).

4. Seat according to claim 3, characterized in that, in each connecting device (7), one end of the support frame (18) is shaped like a fork with two teeth, crossed by the pivot axis (19 ) of the backrest (6) and delimiting a passage for the corresponding sliding axis (11).

5. Seat according to any one of claims 1 to 4, characterized in that the sliding means of each connecting device (7) comprise a hollow cylindrical envelope (12), intended to slide along the sliding axis (11) corresponding, and return means (13) having two ends, respectively integral with the hollow cylindrical casing (12) and the sliding axis (11).

6. Seat according to any one of claims 2 to 5, characterized in that a first lever (23), integral with the pivot axis (17) of the seat (5) and perpendicular thereto, is intended to cooperate with first end of travel stops (24, 25), integral with each of the connecting devices (7).

7. Seat according to any one of claims 1 to 6, characterized in that each connecting device (7) comprises a second lever (20), integral with the axis of rotation (8a, 8b) corresponding, perpendicular to that -ci, and intended to cooperate with second limit stops (21, 22), integral with the arch (3).

8. Seat according to one of claims 6 and 7, characterized in that it comprises damping means (26 to 29) integral with the end of travel stops (21, 22, 24, 25).

9. Seat according to any one of claims 1 to 8, characterized in that the seat (5) is mounted in free rotation around the support frames (16) of the seat (5).

10. Seat according to any one of claims 1 to 9, characterized in that it includes armrests (10a, 10b) integral with the free ends of the lateral branches (4a, 4b) of the arch (3).