Abstract:
A portable chair which, when assembled, supports a user in the prone position and comprises inter-fitting parts allowing the chair assembly to be reconfigurable, adjustable, collapsible and easy to transport. Two side panels are pivotally connected at a straddle edge into which a seat member slidably attaches for supporting the panels in a stable splayed open position. Optional and additional support members inter-fit through corresponding openings in the side panels. Elbow and arm rests removeably attach to the side panels. The hinged connection allows the side panels to rotate between a collapsed to a parallel, closed position to the open position. The various seat member, support members and arm rests removeably attach to an inner wall of the collapsed side panels for easy transportation as one unit.

Description:
FIELD OF THE INVENTION 
   This invention relates to chairs, specifically to a modular and portable chair for supporting a user in an upright or prone position, more particularly a chair for facilitating massage therapy to forming a workstation. 
   BACKGROUND OF THE INVENTION 
   Body massage has long been done by therapists on athletes, and is now more accepted by a larger population for therapeutic and enjoyment purposes. Massage is used more and more as an approach for over all personal heath as well as for a sense of relaxation and to provide tension relief. The general concept of massage is that it requires the client to be securely supported, typically prone on a specifically configured table. This process prohibits some people from getting a massage, or determines that a massage be received at a therapist&#39;s office. 
   There are existing chairs used for administering massages to clients. Clients typically sit in such massage chairs in a position facing the chair so that their back, shoulders, hips and/or neck are supported and accessible to the therapist. Although most of these chairs are portable and may be taken to the client&#39;s home, office, or other location by the therapist, many are bulky and heavy to transport. Also these chairs have many parts, require adjustment once assembled, and are expensive. 
   One type of massage chair uses a form of tubular member for construction of the chair as described in U.S. Pat. No. 5,971,485 to Clark. It teaches a chair with angularly adjustable support struts, adjustable only after the chair is assembled, allowing the chair to accept the body conformations of children, women and men of all sizes. 
   A different approach is U.S. Pat. No. 4,746,167 to Palmer et al. It teaches a portable, knock-down massage chair having a hollow rectangular support base. The base also acts as a case, and while this permits storage and transport of the chair and its many parts, it is bulky. A two-panel brace assembly pivots out of a top opening of the case and is joined to a lid of the case to form a rigid triangular support assembly. A chest support and face cradle are slideably supported to the brace assembly, and an arm rest is joined to the lid panel. A seat member is secured atop side walls of the case and a leg rest is adapted to be secured within the side walls. A lateral brace must be pivoted out from the base to assist in stabilizing the chair. The brace assembly, seat and leg rest can be positioned at variable angles by the use of a number of hardware pieces, once the chair is assembled. 
   Yet another approach is U.S. Pat. No. 4,971,040 to Gillotti. It teaches a portable and collapsible massage chair which is not adjustable. The chair comprises an elongate upright body member with a pivotally connected leg portion. The body member carries a chest and face cushion and has a pair of side panels, with arm cushions extending outwardly from the side panels. A seat cushion and seat support member are pivotally connected to the leg portion, and extend forward through the body member side panels to present the seat cushion beneath the chest cushion. The leg portion, seat cushion, and seat support member are all moveable to be carried within the side panels and create a bulky assembly for storage and transport. 
   A need exists for a compact and portable massage chair that can be easily transported and stowed. Adjustability, durability and affordability are also important elements. Accordingly, it should be quick and easy to assemble and disassemble, as well as be reconfigurable to create different seating angles. It is also desirable that the chair accept a variety of interchangeable parts and accessories. 
   SUMMARY OF THE INVENTION 
   In one embodiment, a portable chair is an assembly of two side panels and a seat member. The side panels and seat member have corresponding slots which inter-fit, the seat member acting to supportably space the side panels in an stable open position for supporting a user in a prone position. Preferably, the side panels are substantially triangular in shape. The panels are pivotally connected at a straddle edge allowing the panels to either open flat or close parallel to each other. The other two edges of the panels, each of different length, act as bases for the chair. Depending on which of the base edges are used, alternative seating angles are created, accommodating users of different size and allowing for different body positions. 
   Accordingly, in a broad aspect, a portable chair is adapted for support on a surface and comprises at least two side panels, each panel having at least a first base edge, adapted to engage the supporting surface, and a straddle edge. The side panels are pivotally joined at the straddle edges enabling the panels to fold between a parallel, closed position and a splayed, open position. At least a first pair of panel slots extend from the straddle edges in each panel, this pair of panel slots being aligned when the panels are in the closed position. A seat member has a pair of seat stops complementary to the first pair of panel slots so that when the panels are in the open position, the pair of seat stops slidably mate with the first pair of panel slots. The seat stops couple with the straddle edges of the panels and further support spacing the panels in the open position. A weight, such as a user or patient, is supported by the seat member which transfers the load through the side panels to a supporting surface such as a floor. 
   The portable chair can be assembled prior to use or during use. Assembly during use aids mobility impaired users by enabling the user to first straddle the panels and thereafter to slide the seat member into the panel slots behind the user&#39;s legs. 
   More preferably, each substantially triangular panel also comprises a second base edge. The first base edge and straddle edge meet to make a first seating angle, and the second base edge and straddle edge meet to make a second seating angle. The seat member and seat stops engage either first or second pairs of panel slots depending on the orientation of the straddle edge. The straddle edges of the chair are contoured for removing superfluous materials and for forming open portions at the end of the panels such as for accommodating a face rest. The straddle edges and seat members are padded. Tab and slot arrangement enable removable arm rests. Further, additional openings and slots can accommodate additional support members extending between the panels for further support of the chair. The seat member, additional support members, and arms can be removable stored on an inner wall of the panels so that when folded to the closed position the panels encase or stow these parts and allow the chair to be transported easily as one unit. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1   a  is an exploded perspective view of one embodiment of the chair indicating the placement of the seat member, panels, and arm rests; 
       FIG. 1   b  is a perspective view of the chair in a preferred embodiment, assembled with additional support members and cushions; 
       FIG. 2  is a plan view of the side panels pivoted open and lying flat. The hinged side panels are shown with a triangular envelope along with panel slots for the seat member and support openings in each side support; 
       FIGS. 3   a – 3   d  is a side view schematic illustrating a series of steps for changing the seating angle of the chair.  FIG. 3   a  shows a user sitting in the chair in the first seating angle.  FIG. 3   b  shows the seat member being removed.  FIG. 3   c  shows the chair in a new second seating angle and indicates the seat member position.  FIG. 3   d  shows a user sitting in the new second seating angle; 
       FIGS. 4   a – 4   c  are a series of front, plan and side views of the chair in stages from the closed position, open position without the seat member, and open position with the seat member.  FIG. 4   a  is a front view of the chair,  FIG. 4   b  is a top view of the chair, and  FIG. 4   c  is a side view of the chair; 
       FIG. 5  is a top view of the side panels illustrating stowing arm rests, support members and the like through removable attachment with hook and loop type fasteners; 
       FIG. 6  is a perspective front view of closed, folded side panels sandwiching seat member and support members therebetween for transportation or storage; and 
       FIGS. 7   a – 7   b  are alternate embodiments of the invention,  FIG. 7   a  showing additional attachments creating surfaces for uses such as a desk, shelving, or pet grooming/podium and  FIG. 7   b  indicates a second pair of arm rests being used as leg rests. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   With reference to  FIGS. 1   a  and  1   b , an embodiment of the invention is an assembly forming a chair  10  having detachable and inter-fitting parts for supporting a user in the upright or prone position such as for facilitating a back massage or for creating work surfaces. Herein, prone is defined as sitting and leaning face down ranging from an almost upright position to a more forward and flat position. The chair  10  comprises two side panels  11  pivotally connected at a straddle edge  12 , at least a first pair of panel slots  20  extending from the straddle edge  12  of side panel  11 , and a seat member  30  that inter-fits to the panel slots  20 . The seat member  30  has a pair of seat stops  31  complementary to the first pair of panel slots. When the panels are in the open position, the seat stops  31  slideably mate with the first pair of panel slots, and couple with the straddle edges  12  of the side panels  11 , spacing and stabilizing the side panels  11  in a stable played position. The entire weight is supported by the seat member  30  which transfers the load through the side panels  11  to a supporting surface such as a floor. 
   As shown in  FIG. 2 , two side panels  11  are pivotally connected to each other through hinge mechanisms  13 . The hinge mechanisms  13  permit a wide range of rotation of the side panels  11  with respect to one another. The side panels  11  fold between a parallel, closed position  35  of zero degrees ( FIG. 6 ), a splayed, open position  36  of about 30 degrees ( FIG. 4 ) and a flat position ( FIG. 5 ). Each side panel  11  has a substantially triangular profile. In other words, the side panels  11  fit within a triangular envelope  40 , although the three edges are not necessarily linear and thus the ends do not necessarily terminate at an apex. The two non-straddle edges of the side panels form first  41  and second base edges  42 . The base edges  41 ,  42  are of different length creating different seating angles depending on which base edge  41 ,  42  is used to support the chair. 
   As shown in  FIG. 3 , the combination of the straddle edge  12  and the first base edge  41  creates a more upright, first seating angle  43  while the straddle edge  12  and second base edge  42  combination creates a more forwardly prone, second seating angle  44 . The different seating angles  43 ,  44  ultimately accommodate users of different size or enable different applications for the chair. 
   The basic steps of assembly and positioning of the chair  10  between two seating angles are shown in  FIGS. 3   a – 3   d . First, the chair  10  is shown positioned on the first base edge  41  in a substantially upright orientation. The seat member  30  slidably mates with the first pair of panels slots  20  enabling a user to sit at the first seating angle  43  ( FIG. 3   a ). To change the seating angle  43 , the seat member  30  slides out ( FIG. 3   b ). The chair  10  is re-positioned on the second base edge  42  and the seat stops  31  are mated with a second pair of panel slots  21  ( FIG. 3   c ). The user can now sit in a more forward prone position at the second seating angle  44  ( FIG. 3   d ). Note that in  FIG. 3   a  or  3   d , the seat member  30  can be mated after the user straddles the straddle edge  12 , sandwiching the user between the seat member  30  and the panels  11 . Assembly after the user straddles the panels  11  aids mobility impaired users by avoiding the need to lift or swing their legs over or around the seat member  30 . 
     FIGS. 1   a  and  1   b  show the assembly of the chair  10  for one seating angle  43  or  44 . The panels  11  are splayed from the closed position  35  (not shown) to the open position  36  (shown). The seat member  30  inter-fits with the first pair of panel slots  20 . The first pair of panel slots  20  extend into the panels from the straddle edges  12  and are aligned with each other when the panels  11  are in the closed position  35 . The seat member  30  has as pair of seat stops  31  which are complementary to the first pair of panel slots  20 . When the side panels  11  are in the open position  36 , the pair of seat stops  31  cooperate and slidably mate with the first pair of panel slots  20  for coupling the seat member  30  with the straddle edges  12  of the side panels  11 . The seat stops  31  spaces the panels  11  in the open position  36 , preventing further opening or closing of the panels  11 . 
   The straddle edges of the chair are contoured for removing superfluous materials and for forming open portions at the end of the panels such as for accommodating an open face rest  92 . The contour creates diverging portions, a first diverging portion  90  above the seat member  30 , and a second diverging portion  91  below the seat member  30 . The diverging portions  90 ,  91  alternatively provide an open face rest  92  when the chair is positioned in either seating angle  43  or  44 .  FIG. 2  illustrates one embodiment of the contouring of the straddle edges  12  of the chair and of the bases  41 ,  42 . 
   A second pair of panel slots  21  extend from the straddle edges  12  and are preferably substantially parallel to the base edge of each panel  11 . The slots are aligned with each other when the panels  11  are in the closed position  35 . The seat member  30  couples with either the first or second pair of panel slots  20 ,  21  when the chair  10  is alternatively positioned in either the first  43  or second seating angle  44 , as shown in  FIG. 3   a – 3   d.    
   Referring back to  FIG. 1   a , in another embodiment a first pair of openings  50  are formed in each of the side panels  11 , intermediate the seat member  30  and a top  45  of the chair  10 , the openings  50  being aligned when the panels  11  are in the closed position  35 . A third pair of panel slots  22  extend from each opening  50 . A first support member  60  having a first pair of support slots  65  inter-fits through the openings  50  and slidably mates with the third pair panel slots  22 . The first support member  60  couples with the side panels  11  and further supports spacing of the side panels  11  in the open position  36 . Additionally, the first support member  60  can act as a support for the user&#39;s upper limbs. For example, the first support member  60  extends beyond each side panel  11  forming an elbow rest  70 , one on each side. Alternatively, the user can extend their arms through the openings  50  for more distributed arm support on the first support member  60 . 
   Preferably, a second pair of openings  51  are formed in each of the side panels  11 , intermediate the seat member  30  and the base of the chair  41 . The openings  51  are strategically placed and are similar to openings  50  in that they are used when the chair  10  is supported on the alternative base edges  41  or  42 , or used concurrently with openings  50 . A fourth pair of panel slots  23  extend from each opening  51 . A second support member  61  having a second pair of support slots  66  inter-fits through the openings  51  and slidably mates with the fourth pair panel slots  23 . The second support member  61  couples with the side panels  11  and further supports spacing of the side panels  11  in the open position  36 . The second support member  61  extends beyond each side panel  11  providing an alternate elbow rest  70 , one on each side, when the chair is positioned in either seating angle  43  or  44 . 
   To add further function to the chair  10 , a first pair of arm rests  80 , one per side panel  11  are removeably secured to the side panels  11 , intermediate the seat member  30  and the top of the chair  45 . A tab  82  extending from each arm rest  80  fits into one of one or more corresponding tab slots  83 , at least one in each panel  11 . The tab  82  frictionally engages the tab slot  83  securing the arm rests  80  in place. As shown in  FIG. 7   b , a second pair of arm rests  81  are optionally secured to the side panels  11 , intermediate the seat member  30  and the base of the chair  41 ,  42 . The second pair of arm rests  81  alternatively provide arm support or act as a leg rests  81  ( FIG. 7   b ) when the chair is positioned in either seating angle  43  or  44 . 
   With reference to  FIG. 1   b , to further facilitate use of the chair  10  for massage, cushions  95  are attached to the arm rests  80 , elbow rests  70 , seat member  30 , along the straddle edge  12  and open face rest  92  for torso, chest and face comfort. The cushions  95  are attached with a hook and loop type fastener  86 , such as VELCRO™, (not seen) for quick and easy assembly and repositioning when the seating angle  43 ,  44  of the chair  10  is changed. 
   With reference to  FIG. 5 , the side panels  11  can be folded open and flat. Support members  60 ,  61 , seat member  30  (not shown), elbow rests  70 , arm rests  80 , and cushions  95  (not shown) are removeably attached to an inner wall  11   a  of side panels  11 , such as with hook and loop type fasteners  86 , for quick and easy assembly and repositioning when the panels  11  are splayed to the open position  36  and when seating angle  43 ,  44  of the chair  10  is changed. Shown in  FIG. 6 , the hinged mechanisms  13  also allow the panels  11  to fold flat for portability and can sandwich the support members  60 ,  61 , seat member  30 , elbow rests  70 , arm rests  80 , and cushions  95  between them, so that the panels  11  and its parts  60 ,  61 ,  30 ,  70 ,  80  and  95  can be easily stowed and transported. 
   With reference to  FIG. 7   a , fifth and sixth panel slots  24 ,  25  extend from the straddle edges  12  of the side panels  11 . The fifth and sixth panel slots  24 ,  25  are additional slots to allow for other embodiments of the invention, including additional surface member  62  to slidably mating with the side panels  11  when in the open position  36 . For horizontal orientation of surface members  62 , the additional slots  24 ,  25  are substantially perpendicular to and cross substantially horizontal first and second panel slots  20 ,  21  respectively. A second additional surface member  63  contains diverging position slots  96  which orient the surface member  63  when lowered over the side panels  11  adjacent what would be the top end  45 . Surface members  62  and  63  can be used as surfaces for such things as a desk, shelf, or pet grooming station/podium. Surface members  62  and  63  can also be removeably attached to the side panels  11  for storage and transportation. 
   A cavity  97  is formed under the splayed panels  11  which can be used for storage when the chair  10  is in the open position  36 . Use of netting or other types of closure between the side panels  11  extending between the base  41 , 42  not currently resting on the surface, for enabling restricted access or egress from the cavity  97 . Examples of uses for other embodiments include such things as a desk, shelf, or pet grooming station or podium.