with reference to fig1 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 fig2 , 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 ( fig6 ), a splayed , open position 36 of about 30 degrees ( fig4 ) and a flat position ( fig5 ). 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 fig3 , 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 fig3 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 ( fig3 a ). to change the seating angle 43 , the seat member 30 slides out ( fig3 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 ( fig3 c ). the user can now sit in a more forward prone position at the second seating angle 44 ( fig3 d ). note that in fig3 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 . fig1 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 . fig2 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 fig3 a - 3 d . referring back to fig1 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 fig7 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 ( fig7 b ) when the chair is positioned in either seating angle 43 or 44 . with reference to fig1 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 fig5 , 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 fig6 , 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 fig7 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 .
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 .