EP0108760A1

EP0108760A1 - Articulated seat.

Info

Publication number: EP0108760A1
Application number: EP83901349A
Authority: EP
Inventors: Jacques Lescure
Original assignee: AMI FRANCAISE SA; AMI SA
Current assignee: AMI FRANCAISE SA; AMI SA
Priority date: 1982-05-19
Filing date: 1983-04-27
Publication date: 1984-05-23
Also published as: BR8307365A; DE108760T1; IT8348322A0; JPS59500849A; DK21984D0; EP0108760B1; AU1477183A; OA07603A; IT1167148B; DE3368501D1; FI834739A0; ATE24383T1; NO834685L; FR2527061A1; DK21984A; FR2527061B1; US4547017A; FI834739A; AU550998B2; WO1983003957A1

Abstract

Le siège articulé comprend au moins un dossier (1) et une assise (2) articulés ensemble suivant un axe mobile (Y-Y'), le dossier étant articulé suivant un axe (X-X'), parallèle à l'axe précité, ce dossier et cette assise étant déplaçables en continu l'un par rapport à l'autre, entre une position assise et une position allongée. Au moins le déplacement de l'assise (2) est guidé à l'opposé de son axe (Y-Y') d'articulation par rapport au dossier (1), suivant une courbe (A-B) déterminée de façon que lorsque le dossier et l'assise se déplacent entre les deux positions précitées, le centre de gravité (G1, M) du corps (8) de l'utilisateur du siège s'écarte d'un plan horizontal (H1) d'une distance (d) suffisamment faible pour que l'utilisateur puisse modifier la position relative du dossier (1) et de l'assise (2) en exerçant sur ces derniers des efforts acceptables, sans avoir à se relever du siège. Utilisation notamment pour des fauteuils de relaxation à positions multiples.The articulated seat comprises at least one backrest (1) and a seat (2) articulated together along a movable axis (Y-Y '), the backrest being articulated along an axis (X-X'), parallel to the aforementioned axis , this backrest and this seat being continuously movable relative to each other, between a sitting position and an lying position. At least the movement of the seat (2) is guided opposite its axis (Y-Y ') of articulation relative to the backrest (1), along a curve (AB) determined so that when the backrest and the seat move between the two aforementioned positions, the center of gravity (G1, M) of the body (8) of the seat user deviates from a horizontal plane (H1) by a distance (d) low enough for the user to be able to modify the relative position of the backrest (1) and the seat (2) by exerting acceptable efforts on the latter, without having to get up from the seat. Use in particular for multi-position relaxation chairs.

Description

"Articulated seat"

The present invention relates to a seat whose various elements, and in particular the backrest and the seat are articulated together along parallel axes, which allows the user to move from a sitting position to a lying position.

Hinged seats are known in which the two aforementioned positions as well as intermediate positions between them can be chosen in advance by the user. When in use of the seat, the user wishes to change position, he is obliged to leave the seat to unlock locking means which fix the seat in its different positions, then / move the seat and the folder in the newly chosen position and / again block the locking means in this position.

All these manipulations are tedious for the user.

In certain seat constructions, the user can modify the inclination of the backrest by actuating a lever or a control button.

When the backrest tilts towards the lying position, the center of gravity of the user's body acts in a favorable direction, which facilitates the movement of the backrest towards this position. However, when the user wishes to move from the lying position to the sitting position, he must necessarily get up in order to be able to straighten the backrest, since the center of gravity of the user's body acts in an unfavorable direction.

The object of the present invention is to remedy the drawbacks of the abovementioned embodiments, by creating an articulated seat which allows the user to continuously modify, the relative positions of the backrest and of

WIPO_ the seat, without having to leave the seat, straighten up or make significant efforts.

The articulated seat covered by the invention comprises at least one back and one seat articulated together on a movable axis, the back being articulated to a support along an axis parallel to the aforementioned axis, this folder and this seat being continuously displaceable relative to one another between a position in which the backrest is substantially vertical and the seat substantially horizontal and a position in which the backrest and seat are substantially horizontal.

According to the invention, this seat is characterized in that at least the movement of the seat is guided opposite its axis of articulation relative to the backrest, along a curve determined so that when the backrest and the 'seat move between the two aforementioned positions, the center of gravity of the body of the seat user deviates from a horizontal plane by a distance small enough that the user can change the relative position of the backrest and the seat by exerting on them acceptable efforts without having to get up from the seat.

Acceptable efforts are understood to mean in particular those which can be deployed by all people, including the elderly and the physically handicapped.

Because the center of gravity of the user's body deviates very little from a horizontal plane, the user is in all the relative positions of the backrest and the seat, in a situation very close to balance, so that it suffices to exert a very slight pressure on the seat or on the backrest to modify its position on the seat. The seat according to the invention thus provides the user with optimal comfort. According to a preferred embodiment of the invention the axis of articulation of the seat, and the axis of articulation of the backrest with the seat as well as the axis of articulation of the backrest, are movable according to fixed guide curves relative to the seat and determined so that the center of gravity of the body of the seat user remains substantially in a horizontal plane for all the relative positions of the backrest and the seat. In such an embodiment, it is possible to obtain that the center of gravity remains practically immobile, which allows the user to instantly modify his position, without having to exert a significant effort on the backrest and / or on the seat. from the headquarters. The guide curves of the aforementioned axes can be defined by grooves fixed relative to the seat in which are engaged rollers fixed to the opposite ends of the aforementioned movable axes.

To move from one position to another of the seat, the user only has to overcome the friction exerted by the rollers in the grooves. This friction can be made very low, by using rollers mounted on ball bearings or anti¬ friction materials such as polytetrafluoroethylene.

Preferably, the seat according to the invention comprises means, such as clamping means, accessible to the hands of the user in position on the seat and making it possible to block at least one of the joints of the seat. and backrest in all seat positions. Other features and advantages of the invention will become apparent in the description below.

In the appended drawings, given by way of nonlimiting examples:

. Figure 1 is a front view of a chair according to the invention;

. Figure 2 is a side view of the chair;

WIPO / y. W1PO . Figure 3 is an enlarged view of a part of the chair of Figure 2, the backrest being folded back;

. Figures 4 to 6 schematically show an armchair in three different positions;

. Figure 7 is a schematic view of the mower representing the three previous positions and the corresponding positions of the user and his center of gravity; . Figure 8 is a side view of an improved version of the chair according to the invention;

. Figure 9 is a front view of this chair;

. FIG. 10 is a partial perspective view of the chair, showing part of the seat and its fixing in the guide grooves;

. Figure 11 is a sectional view along the plane XI-XI of Figure 10;

. Figures 12 to 16 are schematic views of the improved version of the aforementioned chair, in five different positions;

. Figure 17 is a schematic view of the aforementioned chair, showing the five previous positions and the corresponding positions of the center of gravity of the user;

. Figure 18 is a schematic view showing the different positions of a perfec¬ tioned chair comprising a headrest and a footrest.

The embodiment shown in FIGS. 1 to 7 relates to a simplified version of a seat according to the invention. In this example, it is a garden armchair made of plastic. This chair has a backrest 1, a seat 2 and four feet 3,4, the feet 3 carrying at their upper part two armrests 3a. The backrest 1 is articulated along a fixed hori¬ zontal axis XX 'situated at the upper ends of the two rear legs 3. This backrest 1 is itself articulated to the seat 2, along a movable axis Y -Y', parallel - related to the above-mentioned axis XX '. The backrest 1 and the seat 2 are continuously movable, one with respect to the other, between a position in which the backrest is substantially vertical (see FIGS. 2 and 4) and the seat substantially horizontal. which corresponds to a sitting position of the user, and a position in which the backrest 1 and the seat 2 form between them an angle of the order of 120 ° (see FIGS. 3 and 6) allowing the user to s 'lie down. According to the invention, the movement of the seat 2 is guided opposite its axis of articulation YY 'relative to the backrest 1, along a portion of curve AB defined by a fixed groove 5 formed in each side of the seat 2, in flanges 6 perpendicular to the latter. These grooves 5 are available under the support plane of the seat 2 and have an arcuate shape. The concavity of these grooves 5 is directed towards the upper end of the backrest 1.

In these grooves 5 are engaged rollers or ax s 7 fixed to each of the front legs k of the chair.

The portion of curve AB defined by each groove 5 is determined so that when the backrest 1 and the seat 2 are moved according to the different positions represented in FIGS. 5 to 6, the center of gravity (see positions G .., G ₂ , G-. In FIG. 7) of the body 8 of the user (shown schematically in phantom in FIG. 7) deviates from a horizontal plane H., by a distance _d sufficiently small so that the forces required from the user 's body to pass from one position to another are acceptable and that the user does not have to get up from the seat to modify the position of his seat.

The curve A-B defined by the grooves 5 is determined empirically by defining the positions

WIPO relative that must take the folder 1 and the seat 2 so that the center of gravity G .., G „, G., deviates from the horizontal plane H. from a distance ά as small as possible. The different positions of the backrest 1 and of the seat 2 can be blocked by clamping levers 9 fixed on the front feet 4 and accessible by hand of the user, whatever the position of the latter. on the sofa . These levers 9 can be driven at a certain angle by acting on a conventional clamping device, not shown, which prevents any movement of the grooves 5 relative to the fixed rollers 7. This tightening device also blocks the connecting rod a which is connected to the lower edge 1a of the backrest 1. The rollers 7 are advantageously constituted by ball bearings to reduce friction with respect to the grooves 5. These rollers 7 can be replaced by fingers coated with an anti¬ friction material such as polytetrafluoroethylene. The embodiment shown in Figures 8 to 17 relates to an improved version of a treadmill according to the invention.

This chair includes a backrest 10, a seat 11 and four feet 12, 13. On each side of the chair, the upper parts of the front foot 12 and the rear foot 13 are joined by a flange 14 whose upper edge is shaped as armrest 15-

The lower end 10a of the backrest 10 is articulated to the seat 11, along an axis Z-Z '. This axis ZZ ¹ carries on its opposite ends rollers 16 engaged in fixed grooves 17, formed in the flanges 14 (See in particular Figures 10 and 11).

The rear face of the backrest 10 carries a hinge pin VV, the ends of which are provided with rollers 18 engaged in fixed grooves 19, also provided in the flanges 14.

Opposite its rear end, the seat 11 carries a hinge pin WW carrying opposite rollers 20 engaged in corresponding grooves 21. The grooves 17, 19 and 21 make it possible to guide the axes ZZ ', VV and WW along portions of the curve CD, EF, GH, which are determined so that the center of gravity of the user, in position on the chair, remains substantially in a horizontal plane for all the relative positions of the backrest 10 and the 'seat 11.

These different positions are shown diagrammatically in FIGS. 12 to 17.

In these figures, it can be seen that the articulation axis WW of the seat 11 and the articulation axis ZZ 'of the latter with respect to the backrest 10 are located substantially at the same distance, above the bearing surface of the seat 11. Furthermore, the articulation axis VV of the backrest 10 is located behind the bearing surface of the latter at a distance closer to its lower end 10a than from its upper edge 10b. The guide grooves 17 and 21 comprise a first part 17a and 21a making it possible to guide the movement of the seat 11 between a substantially horizontal position (see FIG. 12) and a position inclined towards the rear, at an angle between 20 and 35 ° approximately (see Figures 13 and 14). These guide grooves 17 and 21 comprise a second part 17b and 21b allowing the seat 11 to move upwards, from the above-mentioned position (that of FIG. 14) to the almost horizontal position ( shown in Figure 16).

The guide groove 19 of the articulation axis VV of the backrest 11 comprises a first part 19a allows both to guide the inclination of the backrest 10 between an almost vertical position (FIG. 12) and a position inclined towards the rear at an angle between 110 and 120 ° (see FIG. 14) in which the axis of articulation ZZ 'of the backrest 10 with a seat 11 is located at the end of the first part 17ade the guide groove of this axis.

The guide groove 19 comprises a second part 19b which makes it possible to guide the inclination of the backrest 10 towards an almost horizontal position (see FIG. 16) in which the axis of articulation ZZ 'of the backrest 10 with the seat 11 is located at the end D of the guide groove 17 of the aforementioned axis.

In the example shown in FIGS. 8 to 16, the groove 19 for guiding the axis VV of the articulation of the backrest 10, extends along an arcuate curve whose concavity is directed towards the end D of the guide groove 17 of the axis Z-Z '.

Furthermore, the guide groove 17 of the axis ZZ 'of the articulation of the backrest 10 to the seat 11 is substantially L-shaped. One of the branches of this L which corresponds to the first part 17a of the groove 17 is directed forward and is slightly inclined downward. The other branch which corresponds to the second part 17b is directed upwards with a slight inclination towards the front.

The guide groove 21 of the articulation axis WW of the seat 11 is oriented upwards, in a direction almost parallel to the part 17b of the groove 17 and ends in an arc directed towards the front corresponding to its second part 21b.

In FIG. 17, the different positions of the backrest 10 and of the seat 11 are shown. When the user passes from the seated position (backrest 10

O PI almost vertical) in the lying position (almost horizontal backrest 10) the center of gravity M of its body moves over a very short distance j3, in a horizontal plane H. This result was obtained by giving the guide grooves 17, 19 and 21 of the various axes of articulation of the chair, appropriate shapes which are determined experimentally or graphically. When the user takes the seat in the sitting position, as shown in the figure

12, its center of gravity M is located near the upper end D of the groove 17 for guiding the axis Z-Z '. When the user wishes to tilt the backrest 10, it suffices to unlock a clamping mechanism, of the kind described with reference to the embodiments of FIGS. 1 to 3, then to push with his back slightly against the backrest 10.

The center of gravity M of his body then tends to move down and towards the rear of the chair. However, by tilting the backrest 10, the front of the seat 11 is raised by the fact that it is guided by the groove 21 (see FIGS. 13 and 14), so that the center of gravity M, instead of descending stays in the horizontal plane H _? . At the same time, the backrest 10 and the seat 11 move forward, which has the effect of maintaining the center of gravity near its initial position M, shown in FIG. 12.

Furthermore, on passing from the position shown in FIG. 14 to the positions shown in FIGS. 15 and 16, the center of gravity of the body of the user tends to descend, due to the increase in the inclination of the backrest 10, but this tendency is immediately compensated by an increase, in particular of the rear

O PI sitting back 11.

Since the center of gravity M of the user's body is in all the relative positions of the backrest 10 and of the seat 11 located in a fixed horizontal plane H_, the user is in all cases in a equilibrium situation. He can thus modify his position, in one direction or another, by exerting a light push with his back on the backrest 10 or with his thighs on the seat 11. By exerting this push, the user must overcome only friction rollers 16, -18, 20 in the corresponding grooves 17, 19, 21. However, this friction can be very low, using for rollers 16, 18, 20 ball bearings or axes coated with a anti-friction material, such as tetrafluoroethylene pol.

Furthermore, since the center of gravity K of the user's body moves over a very short distance in the horizontal plane H ", the size of the chair is reduced to a minimum value. Experience has also shown that the weight, size and build of the user are practically without influence, so that in all cases his center of gravity moves horizontally.

In the embodiment of Figure 18, there is shown schematically a chair equipped with the same elements as that shown in Figures 12 to 17. These common elements are therefore assigned identical references. This chair further comprises a headrest 22 articulated with respect to the upper edge 10b of the backrest 10, along a horizontal axis U-U '. The end 22a of the headrest 22 which extends beyond the axis UU 'towards the bottom of the backrest 10, comprises an axis TT' whose opposite ends carry rollers 23 engaged in fixed grooves 24 in the form of an arc formed in the side flanges of the chair.

The I end of the arc defined by each groove 24 is located substantially in the plane of the backrest 10, in the fully raised position, this plane thus being substantially coincident with that of the headrest 22. The opposite end J of the groove 24 is located below the plane of the backrest 10 in the almost horizontal position, the angle comprised between the headrest 22 and the backrest 10 being much less than 180 °. In the intermediate positions, this angle gradually decreases from the most raised position of the backrest 10, where it is equal to 180 °.

This angle a is determined by the shape of the guide groove 24 of the axis T-T '.

When the user modifies the inclination of the backrest 10, the headrest 22 gradually pivots forward, which has the effect, on the one hand, of raising the user's head relative to his body, this which gives the head a comfortable position in all situations. Furthermore, raising the head when the backrest is tilted contributes favorably to maintaining, in a fixed position, the center of gravity of the user's body.

The chair shown in Figure 18 com¬ takes a footrest 25 hinged relative to the front edge 11a of the seat 11, along a horizontal axis S-S '. This footrest 25 is made integral with an axis of articulation R-R * carrying rollers 26 engaged in fixed grooves 27.

The end K of each groove 27 is located substantially in the plane passing through the ends H and D of the grooves 17 and 21 and is located substantially equidistant from these ends H and D.

The other end L of the groove 27 is placed under the front 11a of the seat 11, when the latter is in an almost horizontal position. Due to the shape of the groove 27, the angle b. between the as- seat 11 and the footrest 25 progressively increases between 30 and 180 ° approximately, when the chair is moved from the sitting position to the lying position.

The user's feet and legs occupy the most comfortable position possible in all positions of the chair.

Furthermore, the shape of the grooves 27 is determined so that the position of the feet and legs of the user contributes to maintaining the stationary center of gravity of the user's body in a stationary position.

Thus, in the case of the chair shown in Figure 18, the feet, legs, thighs, trunk and head of the user occupy in all situations, comfortable positions and such that the center of gravity of the whole body remains perfectly still. ^" As a result, the conditions of equilibrium are not likely to be disturbed by inappropriate positions of the legs or the head of the user, which would be likely to move the center of gravity of the body up or downwards, which would then require the user to exert a certain effort to compensate for this displacement of the center of gravity, before being able to modify the position of the chair.

Of course, the invention is not limited to the examples which have just been described and many modifications can be made to them, without departing from the scope of the invention.

Thus, the invention can be applied to any type of seat, comprising at least one backrest and one seat.

Furthermore, the invention is also applicable to a seat such as a bed base made up of elements articulated together, along n + 1 axes parallel, each element being intended to serve as a support for an articulated part of the user's body, such as the legs, thighs, trunk and head. The axes of articulation of these elements could be mobile, along guide curves defined by grooves, ramps or cams, determined so that the center of gravity of the body of the user, in position on these elements, remains substantially in a horizontal plane for all the relative positions of these elements. In this way, the user can modify the relative positions of these various elements by adapting them to the positions he wishes to obtain, without having to get up or deploy too much effort. Furthermore, given that the articulated elements of the seat according to the invention are in substantially indifferent equilibrium, provision could be made to motorize the movement of the aforementioned elements between their extreme positions of movement by means of a low power motor. controlled by the user. Indeed, such an engine will have to overcome only reduced and substantially constant forces for all the relative positions of the articulated elements. This motor could thus be powered for example by a single battery, which is particularly convenient especially in the case of a garden chair.

O PI

Claims

1. Articulated seat comprising at least one back (1, 10) and a seat (2, 11) articulated together along a movable axis (Y-Y ', ZZ *), the back being articulated to a support following a axis (XX', VV ) parallel to the aforementioned axis, this backrest and this seat being continuously movable relative to each other between a position in which the backrest is substantially vertical and the seat is substantially horizontal and a position in which the backrest and the seat are substantially horizontal, characterized in that at least the movement of the seat (2, '11) is guided opposite its axis (Y-Y', Z-Z ') of articulation with respect to the backrest (1, 10) along a curve (AB, GH) determined so that when the backrest and the seat move between the two above-mentioned positions, the center of gravity (G _{1 »} M) of the body of the seat user deviates from a horizontal plane (H .., H_) by a distance (d) small enough that the user can modify er the relative position of the backrest (1, 10) and the seat (2, 11) by exerting on the latter acceptable forces, without having to get up from the seat.

2. Seat according to claim 1, characterized in that the backrest (1) is articulated along an axis (XX ') fixed relative to the seat and is articulated at the seat (2) along an axis (YY *) fixed compared to the latter.

3- seat according to claim 1, characterized in that the axis of articulation (V-V) of the backrest (10), the axis of articulation (Z-Z *) of the backrest

(10) with the seat (11) and the hinge pin (WW) of the seat (11) are movable along guide curves (EF, CD and GH) fixed relative to the seat and determined so that the center of gravity ⁽ M ⁾ of the seat user's body remains substantially in a horizontal plane (H.) for all the relative positions of the backrest and the seat.

4. Seat according to any one of claims 1 to 3, characterized in that the guide curves (CD, EF, GH) of the movable axes are defined by grooves (17, 19, 21) fixed relative to the seat , in which are engaged rollers (16, 18, 20) fixed at the opposite ends of the aforementioned movable axes.

5. Seat according to any one of claims 3 or 4, characterized in that the axis (WW) of articulation of the seat (11), and the axis (Z-Z ') of arti¬ culation of the latter relative to the backrest (10) are located above the bearing surface of the seat (11) and in that the axis (VV) of articulation of the backrest

(10) is located at the rear of the backrest support surface.

6. Seat according to any one of claims 1 to 5, characterized in that it comprises means (9) accessible to the hands of the user in position on the seat, allowing to block at least one of the joints seat (2, 11) or backrest (1, 10) in all positions of the seat.

7. Seat according to any one of claims 3 to 6, characterized in that the guide curve (G-H, C-D) of the axes of articulation of the seat

(11) and the latter with the backrest (10) comprise a first part (21a, 17a) for guiding the inclination of the seat between a substantially horizontal position and a position inclined towards the rear, at an angle included between 20 and 35 ° approximately and a second part (21b, 17b) allowing the seat to move upwards, from the above-mentioned position to a substantially horizontal position.

8. Seat according to claim 7, characterized in that the guide curve (EF) of the articulation axis (VV) of the backrest (10) comprises a first part (19a) making it possible to guide the inclination of the backrest between an almost vertical position and a position inclined towards the rear at an angle of between 110 and 120 ° approximately, in which the axis of articulation (Z-Z ') of the backrest (10) with the seat ( 11) is located at the end of the first part (17a) of the guide curve (CD) of this axis, and a second part (19d) making it possible to guide the inclination of the backrest (10) towards an almost horizontal position wherein the ^* axis of articulation (Z-Z ') of the backrest (10) with the seat (11) is located at the end (D) of the second part of the guide curve (CD) of this axis.

9. Seat according to any one of claims 7 or 8, characterized in that the guide curve (EF) of the hinge axis (VV) of the backrest (10) is an arcuate curve whose concavity is directed towards the end (D) of the guide curve (CD) of the axis of articulation of the backrest with the seat, in that the guide curve of the axis (Z-Z ') of the backrest with l 'seat is substantially L-shaped, one of the branches (17a) extends forward and is inclined downward and the other branch (17b) extends upward and in that the curve guide (GH) of the articulation axis (WW) of the seat (11) has a rectilinear part (21a) substantially parallel to the second branch (17b) of the shaped guide curve (CD) L, the end of this rectilinear part having an arc (21b) directed towards the front.

10. Seat according to any one of claims 3 to 9, characterized in that the positions

O PI extremes of the guide curves (CD, EF, GH) of the different moving axes are determined so that the center of gravity (M) of the body of the seat user remains substantially stationary for all the relative positions of the backrest (10) and of the seat (11).

11. Seat according to any one of claims 3 to 10, further comprising a headrest (22) articulated at the upper edge (10b) of the backrest

(10) along an axis (UU *), characterized in that this headrest comprises an articulation axis (TT ') parallel to the previous one and movable along a guide curve (IJ) determined so that the center of gravity of the user's body remains substantially in a horizontal plane for all the relative positions of the headrest (22), the backrest (10) and the seat (11).

12. Seat according to any one of re¬ vendications 3 to 11, further comprising a footrest (25) articulated at the front end (11a) of the seat

(11) along an axis (SS '), characterized in that this footrest comprises an articulation axis (R-R') parallel to the previous one and movable along a guide curve (KL) determined in such a way that the center of gravity of the user's body remains substantially in a horizontal plane for all the relative positions of the footrest (25), the backrest (10) and the seat (11).

13- Seat composed of n elements articulated together along n + 1 parallel axes, each element being intended to receive an articulated part of the body of the user, characterized in that the axes of articulation of these elements are movable along guide cour¬ bes determined so that the center of gravity of the body of the user, in position on these elements, remains substantially in a horizontal plane for all the relative positions of the various aforementioned element.