Title of Invention

A CHAIR, IN PARTICULAR FOR AN AUDITORIUM

Abstract

The invention relates to a chair, in particular for an auditorium, characterised in comprising a base (2), an horizontal support plate (3), secured to the base (2), a movable carriage (5), sliding on the support plate, said carriage supporting the chair seat and comprising two columns (10) on the rear end thereof, through which an horizontal axis (11) extends, to which a support (12) for the chair back is hinged, a first connecting rod (13), hinged to the support plate (3), a second connecting rod (16), hinged to the first connecting rod (13), to the carriage (5) and to a third connecting rod (20) which extends towards the rear of the chair, the end of which is hinged to the lower end of the back support (12) and a return element, for the return of the movable carriage (5) towards the rear of the chair.

Full Text

A chain in particular for an auditorium The invention relates to the field of chairs, in particular for entertainment or conference auditoria. In entertainment auditoria, the chairs are normally disposed in closely packed rows in order to make the best possible use of the space available, in particular in the case of chairs with seats which may be raised. The legs of seated spectators thus fill most of the space between two rows of seats. When a spectator wishes to sit on a chair in the middle of the row, any spectators already seated on chairs at the beginning of the row are normally forced to get up in order to let the new arrival pass, which is obviously very inconvenient. To attempt to remedy this drawback, chairs have been designed in which the seat, which cannot be raised, may perform a rearward movement under the action of a force exerted by the spectator’s legs. This consequently provides a temporary additional space between the front of the chair and the row of seats in front of it, enabling the new arrival to pass without making it necessary for the user of the chair to stand up. However, in chairs of this known type, this rearward movement of the seat goes together with a significant rearward movement of the chair back. This makes it necessary to provide sufficient space behind the chair, especially if it disposed in front of a wall. This movement may also disturb spectators seated in the row behind the chair in question. The object of the invention is to provide a chair for an auditorium which is free from these drawbacks.. For this purpose, the invention relates to a chair, in particular for an auditorium, characterised in that it comprises a base secured to the floor, a horizontal support plate secured to the base, a movable carriage sliding on the support plate, which carriage bears the chair seat and comprises, at its rear end, two columns through which there extends a horizontal axis on which a support for the chair back is articulated, a first connecting rod articulated on a support plate, a second connecting rod articulated on the first connecting rod, on the front part of the carriage and on a third connecting rod extending towards the rear of the chair, the end of which is articulated on the lower end of the chair back support, and a return member tending to return the movable carriage towards the rear of the chair. The movable carriage may slide horizontally on the support plate. The sliding of the movable carriage on the support plate may be enabled by slideways. The sliding of the movable carriage on the support plate may be enabled by ball or roller members. The return member may be a coil spring connecting the support plate and the carriage. The return member may be a pneumatic spring connecting the support plate and the carriage. The return member may be a weighting member tending to entrain the axis of articulation of the first connecting rod and of the second connecting rod downwards. The base may be formed by a single column member. As will have been appreciated, the invention consists first in securing the chair seat on a movable carriage mounted to slide on a support which is itself secured to the floor. The chair back support is, moreover, articulated on the carriage and a system of connecting rods articulated on the carriage support, on the carriage and on the chair back support makes it possible to prevent, during the movements of the chair seat, the chair back from projecting into the space which should normally be available behind the chair. The invention is set out in the following description made with reference to the accompanying drawings, in which: Fig. 1 shows, in profile and longitudinal section, the mechanical members of the chair of the invention in the retracted position; Fig. 2 shows, in a similar manner, the mechanical members of the chair in the extended position. In Figs. 1 and 2, the chair of the invention is shown in an uncovered state, i.e. without the cushions forming the seat and the back, for greater clarity. The chair for an auditorium of the invention is secured to the floor 1 by means of a base 2. The latter preferably takes the form of a single column member. A horizontal support plate 3 with a U-shaped section open at the top is secured to the base 2. It has a raised front edge 4. Horizontal slideways (not shown in the drawings) are disposed on the outer lateral walls, i.e. on the vertical arms of the U, of this support plate 3. A movable carriage 5 slides horizontally on the support plate 3 by means of slideway members 6 corresponding to the slideways of the support plate 3. On the front portion of its upper surface 7, the movable carriage 5 comprises fastening means 8, 9 for the cushion forming the chair seat. At the rear end of its upper surface 7, the movable carriage 5 comprises two spaced columns, one of which is shown in the drawings by reference numeral 10. These columns 10 are traversed by a horizontal axis 11 on which there is articulated a support 12 on which the cushion forming the chair back is fitted. These various members are connected to one another by a system of connecting rods, made up as follows: - a first straight connecting rod 13, a first end of which is articulated about a horizontal axis 14 connected to the support plate 3 for instance, as shown, by passing through a lug 15 rigid with the lower surface of the support plate 3; - a second straight connecting rod 16 through which three horizontal axes of articulation pass; the first axis 17 articulates the second end of the first connecting rod 13 on a first end of the second connecting rod 16; the second axis 18 articulates the second connecting rod 16 on the front portion of the movable carriage 5 and passes through the second connecting rod 16 in a region close to its second end; the third axis 19 articulates the second end of the second connecting rod 16 on a first end of a third connecting rod 20; - this third connecting rod 20 is bent in the embodiment shown; it has a first oblique portion 21 oriented towards the rear of the chair and descending in the direction of the support plate 3, and a second portion 22 which extends substantially horizontally towards the rear of the chair; the second end of this third connecting rod 20 is articulated by a horizontal axis 23 on the lower end of the chair back support 12. An indentation provided in the upper surface 7 of the movable carriage 5 enables the passage and the movements of the second connecting rod 16 whose upper end articulated on the third connecting rod 20 has to be able to move in the space between this upper surface 7 and the fastening means 8, 9 of the chair seat. The mechanism is supplemented by a return member tending to recall the movable carriage towards the rear of the chair, for instance a resilient member working in horizontal extension, such as a pneumatic spring 24 (as shown) or a coil spring. A first end 25 of the resilient member is secured on the raised front edge 4 of the support plate 3 and the second end 26 of the resilient member is secured on the movable carriage 5 by means of a member 27. A set of abutments, whose positions may preferably be adjusted, makes it possible to limit the amplitude of the movements of the movable carriage 5 on the support plate 3. At rest, when the spring 24 is extended, the chair is in the configuration shown in Fig. 1 and has its minimum bulk. The movable carriage 5 is in a retracted position, the second portion 22 of the third connecting rod 20 is in a horizontal position and the chair back support 12 is in a vertical position. When a spectator sits on the chair, the pressure that he or she exerts on the chair back counters the action of the spring 24 and tends to cause: - the back support 12 to move in rotation about the axis 11 in the direction of the arrow 28; - the movable carriage 5 to move forwards in horizontal translation in the direction of the arrow 29. The chair is then, when the movements have reached their maximum extension, in the configuration shown in Fig. 2 in which it has its maximum horizontal bulk. The movable carriage 5 is in a forward position. The second Dortion 22 of the third connecting rod 20 is in a slightly oblique position because :he axis 23 passing though its end has been displaced upwards under the effect }f the rotation about the axis 11 of the back support 12 which is itself in an oblique position, with an angle a with respect to vertical. The spring 24 is in the compressed state. Since the axis of rotation 11 of the back support 12 has moved in translation towards the front with the movable carriage 5. it is as though in practice the back support 12 had moved in rotation about a virtual point of rotation P disposed vertically to its initial position and substantially above its upper end. It follows that when the spectator is seated, the back in its inclined position does not project into the space E situated to the rear of the back when the chair is at rest. The inclination of the back, like its return to the vertical position, may therefore take place without in any way disturbing the spectators in the row situated behind the chair in question and with no risk of the chair back striking a wall if the chair is in the final row. When a spectator seated on the chair wants to let a spectator heading for another chair of the row pass, he or she merely has to push down on his or her feet in order to exert a force, assisted by the spring 24, on the chair mechanism which returns the movable carriage 5 into the retracted position and the back support 12 into the vertical position as in Fig. 1. The spectator does not need to get up and can then return immediately to his or her normal seated position by discontinuing his or her pushing force on the floor. Optionally, a device may be provided to lock the spring 24 in its compressed position and/or in one or a plurality of intermediate extended positions. In this way, the spectator may give the chair the fixed configuration of his or her choice, in particular as regards the inclination of the back. However, this characteristic feature may not be preferred. In practice, leaving the spring 234 (or, in general, the return member of the movable carriage 5) to work freely in a permanent manner makes it possible to ensure that when the spectator stands up, the chair returns automatically to its rest position and thus leaves the maximum space behind it for spectators leaving the row. This ensures maximum security if it is necessary rapidly to evacuate the auditorium. Typically, the device of the invention may enable a horizontal movement of the chair seat of the order of 15 to 20 cm with an angle a of maximum inclination of the back of the order of 15°. Other advantages of the device of the invention are in particular the simplicity of its design and its production which is very economic, and also the fact that all its operational members are disposed below the chair seat. The lateral bulk of the chair may therefore be identical to that of a chair of conventional type. Moreover, as has been seen, the mechanism is compatible with the use of a base with a single column member which is the type of base which it is preferred to use nowadays. However, any other type of base could also be used. It can therefore be envisaged to replace chairs of conventional type by chairs of the invention while retaining their original bases. Lastly, the fact that the movements of the seat and the back take place smoothly and are fully synchronised and fully reversible provides excellent ergonomics in use. It will be appreciated that other variants could be envisaged with respect to the invention as described above. For instance, the sliding of the movable carriage 5 on the support plate 3 may be enabled by devices other than slideways, for instance by ball or roller members. This sliding may not be rectilinear, but, for instance, curvilinear. The support plate 3 may be fully integrated in the base. It may have a shape other than that shown, the main factor being that it enables the installation of the sliding means of the movable carriage 5. Similarly, the shapes of the fastening members 8, 9 of the seat and of the back support 12 may be modified. The seat could even be incorporated during production in the carriage 5 and/or the back in the support 12. In order to bring the mechanism from the extended position to the retracted position, types of member other than the resilient member 24 could also be envisaged, for instance a weighty member tending to entrain the axis of articulation 17 of the first two connecting rods 13, 16 downwards. This weighty member could, for instance, be the axis of articulation 17 itself or a member incorporated in one of the connecting rods 13, 16. Lastly, the third connecting rod 20 does not necessarily have to be bent: it could just as well be straight. CLAIMS 1. A chair, in particular for an auditorium, characterised in that it comprises a base (2) secured to the floor (1), a horizontal support plate (3) secured to the base (2), a movable carriage (5) sliding on the support plate (3), which carriage (5) bears the chair seat and comprises, at its rear end, two columns (10) through which there extends a horizontal axis (11) on which a support (12) for the chair back is articulated, a first connecting rod (13) articulated on the support plate (3), a second connecting rod (16) articulated on the first connecting rod (13), on the front part of the carriage (5) and on a third connecting rod (20) extending towards the rear of the chair, the end of which is articulated on the lower end of the chair back support (12), and a return member tending to return the movable carriage (5) towards the rear of the chair. 2. A chair as claimed in claim 1, characterised in that the movable carriage (5) slides horizontally on the support plate (3). 3. A chair as claimed in claim 1 or 2, characterised in that the sliding of the movable carriage (5) on the support plate (3) is enabled by slideways. 4. A chair as claimed in claim 1 or 2, characterised in that the sliding of the movable carriage (5) on the support plate (3) is enabled by ball or roller members. 5. A chair as claimed in one of claims 1 to 4, characterised in that the return member is a coil spring connecting the support plate (3) and the carriage (5). 6. A chair as claimed in one of claims 1 to 4, characterised in that the return member is a pneumatic spring (24) connecting the support plate (3) and the carriage (5). 7. A chair as claimed in one of claims 1 to 4, characterised in that the return member is a weighty member tending to entrain the axis (17) of articulation of the first connecting rod (13) and of the second connecting rod (16) downwards. 8. A chair as claimed in one of claims 1 to 7, characterised in that the base (2) is formed by a single column member.

Documents:

1403-chenp-2006 abstract-duplicate.pdf

1403-chenp-2006 claims-duplicate.pdf

1403-chenp-2006 description (complete)-duplicate.pdf

1403-chenp-2006 drawings-duplicate.pdf

1403-chenp-2006-abstract.pdf

1403-chenp-2006-claims.pdf

1403-chenp-2006-correspondnece-others.pdf

1403-chenp-2006-description(complete).pdf

1403-chenp-2006-drawings.pdf

1403-chenp-2006-form 1.pdf

1403-chenp-2006-form 3.pdf

1403-chenp-2006-form 5.pdf

1403-chenp-2006-pct.pdf