Abstract:
A foldable apparatus for providing a surface and storage for a person of any age to use for play or engage in activities while mobility is being restricted having rotatable joints with locking device and located at corresponding members for optimum space saving. In some embodiments of this invention, the height of the apparatus can be adjusted by operating the devices in the vertical members of said apparatus.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a seating arrangement. More particularly, the invention relates to a backrest assembly for a seating arrangement.  
         BACKGROUND TO THE INVENTION  
         [0002]    Certain modern, upholstered items of furniture have low backrests. While conveying an attractive appearance to the item of furniture, prolonged sitting in such furniture can cause discomfort due to lack of support of an occupant&#39;s back. Incorrect lumbar support can also result in medical complications, particularly with people suffering from back problems.  
         SUMMARY OF THE INVENTION  
         [0003]    According to the invention; there is provided a seating arrangement which comprises:  
           [0004]    a seat base;  
           [0005]    a seat back extending upwardly from the seat base;  
           [0006]    a backrest displaceably arranged relative to the seat base between a first, retracted position in which the backrest is substantially in register with the seat base and a second, extended position in which at least a part of the backrest protrudes upwardly beyond a top edge of the seat back; and  
           [0007]    a displacement mechanism arranged between the seat back and the backrest, the displacement mechanism effecting displacement of the backrest from its first position to its second position.  
           [0008]    In a preferred embodiment of the invention, the seating arrangement is in the form of lounge furniture. For example, the seating arrangement may be an armchair, a couch or sofa, or the like. It will be appreciated that such furniture is normally upholstered, padded furniture.  
           [0009]    Further, such furniture normally has framework supporting the upholstery. Accordingly, the seat base, the seat back and the backrest may each comprise an upholstered frame. At least the seat back frame and the backrest frame may each be box frames. If desired, the backrest frame may carry a suspension assembly for increasing the comfort of the backrest.  
           [0010]    The seating arrangement may include a locking mechanism, the locking mechanism locking the backrest in at least its first position relative to the seat base. The locking mechanism may include an engageable member, in the form of a locking pin, carried on one of the seat back and the backrest, the other of the seat back and the backrest carrying an engaging member, in the form of a catch plate, which engages the engageable member when the backrest is in its first position relative to the seat back. Preferably, the locking pin is carried on the frame of the backrest with the catch mechanism being carried on the frame of the seat back.  
           [0011]    The seating arrangement may include an operating mechanism that operates the engaging member for releasing the engageable member. This enables the backrest to rise relative to the seat back to its second, extended position under the effect of the displacement mechanism. The operating mechanism may be a concealed operating mechanism that includes a release cable, co-operating with the locking mechanism, and a handle concealed beneath or beside a cushion on the seat base.  
           [0012]    The displacement mechanism may be a fluid operated displacement mechanism. More particularly, the fluid operated displacement mechanism may be in the form of at least one pneumatic piston/cylinder assembly.  
           [0013]    The seating arrangement may include a guide means, the guide means guiding the displacement of the backrest relative to the seat back. The guide means may comprise at least one and, preferably, a pair of guide shafts extending in the direction of displacement of the backrest relative to the seat back. A guide sleeve may be slidably arranged on the, or each, guide shaft. Preferably, the, or each, guide shaft is carried on the frame of the seat back with the, or each, sleeve being carried on the frame of the backrest. Where a pair of guide shafts and sleeves are provided, the guide shafts may be transversely spaced with respect to each other.  
           [0014]    Preferably, the displacement mechanism is a concealed displacement mechanism interposed between the seat back and the backrest, the displacement mechanism permitting reversible displacement of the backrest from its first position to its second position. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    The invention is now described by way of example with reference to the accompanying diagrammatic drawings in which:  
         [0016]    [0016]FIG. 1 shows a three-dimensional, front view of a seating arrangement in accordance with an embodiment of the invention;  
         [0017]    [0017]FIG. 2 shows a three-dimensional, front view of a part of the seating arrangement of FIG. 1;  
         [0018]    [0018]FIG. 3 shows a three-dimensional, bottom view of a locking mechanism of the seating arrangement;  
         [0019]    [0019]FIG. 4 shows a three-dimensional view of a displacement mechanism of the seating arrangement; and  
         [0020]    [0020]FIG. 5 shows a three-dimensional view of a guide means of the seating arrangement. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    In the drawings, reference numeral  10  generally designates a seating arrangement, in the form of a sofa, in accordance with an embodiment of the invention. The sofa  10  comprises a seat base  12 . A seat back, which is indicated at  14  in FIG. 2 of the drawings, extends upwardly from a rear edge of the seat base  12 .  
         [0022]    A backrest  16  is displaceably arranged relative to the seat back  14 . In the illustrated embodiment, the sofa  10  has two independently displaceable backrests  16 . The seat back  14  is, correspondingly, divided into two parts, one associated with each backrest  16 . It will be appreciated, however, that the invention is equally applicable to seating arrangements having a one-piece seat back and/or backrest.  
         [0023]    As illustrated more clearly in FIG. 2 of the drawings, each part of the seat back  14  has a box frame  18  carrying padding and upholstery (not shown). Similarly, each backrest  16  has a shaped box frame  20  which carries padding and upholstery. In addition, the frame  20  of each backrest  16  carries a suspension assembly anchored at points  22 . The suspension assembly is omitted for the sake of clarity but is a commercially available suspension assembly such as that sold under the Registered Trade Mark, Pullmaflex (Pullmaflex is a Registered Trade Mark of Leggett-Platt Inc., a USA company).  
         [0024]    Each backrest  16  is displaceably arranged relative to its associated part of the seat back  14  between a first, retracted position in which a bottom of the backrest  16  is received between the seat base  12  and the seat back  14  and a second, extended position, as shown in FIG. 2 of the drawings, where a top of the backrest  16  stands proud of, and extends above, a top of the seat back  14 .  
         [0025]    The sofa  10  includes a fluid-operated displacement mechanism in the form of a pneumatic piston/cylinder assembly  24 . A piston/cylinder assembly  24  is associated with each backrest  16  and is interposed between the backrest  16  and its associated seat back  14 . One end  24 . 1  of the piston/cylinder assembly  24  is secured to a gusset plate  26  at a rear of the frame  20  of the backrest  16 . An opposed end  24 . 2  of the assembly  24  is secured to a housing  28  on a cross member  29  at a bottom of the front of the frame  18  of the seat back  14 .  
         [0026]    The housing  28  houses a locking mechanism  30  (FIG. 3) which locks the backrest  16  in its retracted position relative to the seat back  14 .  
         [0027]    The locking mechanism  30  includes a locking pin  32  (FIGS. 3 and 4) carried on a cross member  34  of the frame  20  of the backrest  16 . The locking pin  32  has a circumferential groove  32 . 1  formed in its periphery. A catch plate  36  is pivotally mounted in the housing  28  to pivot in a plane in which the catch plate  36  lies. An urging means, in the form of a spring  38 , biases the catch plate  36  towards one side of the housing  28 , as shown in FIG. 3 of the drawings, so that the catch plate  36  is received in a part of the groove  32 . 1  of the locking pin  32  in a rest position of the catch plate  36 .  
         [0028]    An operating mechanism, comprising a cable  40  and a handle (not shown), acts on the locking mechanism  30 . One end of the cable  40  is secured to the catch plate  36  with the other end of the cable  40  being secured to the handle. The cable  40  and the handle are concealed behind or beneath a cushion of the seat base  12  of the sofa  10 .  
         [0029]    A pair of transversely spaced guide bars  42  of a guide means is carried on the frame  18  of the seat back  14 . Each guide bar  42  slidably receives a sleeve  44 , carried on the frame  20  of the backrest  16 . The guide bars  42  and guide sleeves  44  serve to inhibit skewing of the backrest  16  relative to the seat back  14  as the backrest  16  is displaced relative to the seat back  14 .  
         [0030]    In use, the backrest  16 , in its retracted position, lies substantially in register with the seat back  14  to provide a modern, low-backed appearance to the sofa  10 . The backrest  16  is held in its retracted position by the catch plate  36  of the locking mechanism  30  engaging the groove of the locking pin  32 .  
         [0031]    When it is desired to support a higher lumbar region of a person&#39;s back, when the person is seated on the sofa  10 , the operating mechanism is operated. This is effected by pulling the cable  40  in the direction of arrow  46 . When this occurs, the catch plate  36  is pivoted against the action of the spring  38  to clear the groove of the locking pin  32  to release the locking pin  32 . The backrest  16  rises under the action of the pneumatic piston/cylinder assembly  24  to the position shown in FIG. 2 of the drawings.  
         [0032]    In this position, the backrest  16  supports the person&#39;s back in a higher region of the person&#39;s back.  
         [0033]    When it is desired to return the backrest  16  to its retracted position  14 , pressure is applied to the top of the backrest  16  to urge the backrest  16  downwardly, against the action of the piston/cylinder assembly  24 , until the locking pin  32  is engaged and is locked by the locking plate  36 .  
         [0034]    It is a particular advantage of the invention that a seating arrangement  10  is provided which, while having an attractive, modern appearance when the backrest  16  is in a retracted position, provides a more orthopaedically suitable support when the backrest  16  is in a raised position relative to the backrest  14 . The use of the pneumatic piston/cylinder assembly  24  provides an appealing, damped motion to the backrest  16  when it rises relative to the seat back  14 . Further, the use of this assembly  24  reduces the effort required to raise the backrest  16  relative to the seat back  14  and facilitates the returning of the backrest  16  to its retracted position.  
         [0035]    It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.