The invention concerns an adjustable arrangement for reclining or seating furniture, wherein the piece of furniture has three mutually adjustable, articulated members, constituting a back member (R), a seat member (S) and a foot member (F), which together form an adjustable frame for support of a mattress, cushion, upholstery or the like, where the adjustable frame is mounted in a support member (A) by means of horizontal axles/dowels/stays/sliding elements or the like, which constitute fulcrums (2, 3, 5) for the mutually adjustable, articulated members (R, S, F), where the back member (R) and one of the two other elements (S or F) have a fixed, immovable fulcrum (2) in relation to the support member (A), the fulcrum of the back member being located at a distance from the linkage (1) to the seat member, and by which:
a) the seat member""s fulcrum (3) or the foot member""s fulcrum (5) is immovable and securely attached to the support member""s (A) suspension point (12 or 13),
b) the fulcrum (3 or 5) which is not immovable and securely attached to the support member (A) is movable forwards and backwards in the furniture""s longitudinal direction in sliding elements/sliding tracks (12 or 13) on the support member (A),
The terms reclining or seating furniture describe all types of furniture where it may be appropriate to adjust the user position, e.g. a bed, chaise longue, divan, bench, sofa, chair, etc. The furniture frame, composed of articulated parts, which forms the support for the furniture""s upholstery, arrangement of cushions, a mattress or the like, is mounted in a support member, which may be a side member, gable, frame or other fixed components. The terms furniture, frame, support member are used in the following and in the patent claims are based on these definitions. In this connection it should also be noted that the support for the mattress, cushions etc. will naturally also form the support for the user of the furniture.
There are previously known a great number of different designs of adjustable reclining or seating furniture. Examples of such articulated designs can be found in the applicant""s international patent applications nos. WO97/37567, WO98/37792 and WO98/37791. Articulated furniture of this kind is widely used within the health sector, e.g. in connection with hospital beds, but is also employed to an ever-increasing extent as ordinary furniture. The adjustments of the furniture""s parts to the various user positions may be performed by motor power, which may be electrically, hydraulically or pneumatically driven. Other possibilities are mechanical operation via adjusting levers, or by the user taking hold of a part of the furniture and moving it by hand. In this connection it is referred to Norwegian Patent number 43103. An arrangement with two adjustable members is shown in DE OS number 1 779 576.
The present invention concerns adjustable reclining or seating furniture in which it should be possible to perform the adjustment entirely without or with minimal help from external power sources, while at the same time it should be possible to perform the adjustment of the furniture with a minimal exercise of force, directly by the user while he is reclining/sitting on the piece of furniture. Thus it should be possible to perform a readjustment of the furniture, e.g. from a reclining position to a sitting position and back or to assume intermediate positions, essentially by the user simply performing a xe2x80x9cnatural movementxe2x80x9d, with the result that the furniture xe2x80x9cfollowsxe2x80x9d when the user readjusts from one position to the other.
In WO 98/37791 an example of this type is described, where a spring mechanism, e.g. a gas spring is adapted in such a manner that a user can alter the angular position between back member, seat member and possibly foot member merely by leaning forward or back against the back member. The furniture can be locked in the desired position by locking the spring mechanism.
When this furniture is used with a cover such as a mattress, in the area between the seat and the back a xe2x80x9ccompressionxe2x80x9d will be formed, where the mattress is shifted by a displacement of the seat member, thus producing a certain amount of additional resistance from the mattress, which also has to be overcome.
This can lead to a rather uneven resistance which has to be overcome with the result that the user has to use more force in certain positions.
The object of the present invention is to avoid this problem and provide an embodiment of a piece of furniture of the type mentioned in the introduction, which offers less mattress resistance and thereby a more uniform exercise of force for the user over the area of movement of the whole piece of furniture. This is achieved with an arrangement of the type mentioned in the introduction, which is characterized by the features presented in the patent claims.
By simple means the invention offers the advantage that the seat member can also be rotated about a fixed axis point, possibly with only a small lateral movement, with the result that the mattress""s resistance to a change in shape does not affect the movement. In addition the user will also move to a minimal extent in the furniture""s longitudinal direction during adjustment, thereby also reducing the requirement for adjustment force. During adjustment the mattress""s seat and foot members will thereby be able to remain almost at rest on the adjustment system""s approximately immovable seat and foot members on account of, among other things, the user""s weight and material friction. The seat member""s extension enables the mattress""s back portion to bend about the mattress""s own almost stationary seat and foot members, thereby only xe2x80x9cinchingxe2x80x9d to a minimal extent in the furniture""s longitudinal direction during adjustment.
It will hereby be possible to alter the angle between the back and seat members between 180xc2x0 and up to approximately 90xc2x0 while the angle between the seat and foot members may be altered between 180xc2x0 and up to approximately 220xc2x0.
The inventive concept is based on the fact that the seat member is equipped with an extension member which is particularly advantageously arranged between the seat member and the back member. In its simplest form this extension is designed as a rod extension, which is telescopically movable in a tube member of the seat member""s frame. The telescopic extension may in itself be a gas spring or an electrical actuator. However, the invention also includes other types of devices for achieving the desired extension, e.g. the extension member may be in the form of a scissors member or a rod which is movable in a guide track on an arm on the bottom of the back member. All such embodiments are intended to fall within the term extension member.