50 supported thereon to a position in which the rear tracks 73 are adjacent to or resting on the upper surface of the bed 34 the tracks 73 are then astride the thighs 32t of a person 32 seated on the bed as illustrated in fig3 the back support tie down bar 115 will then be removed from the clips 116a and moved downwardly to be received by the slots 116 the cloth back support 10 moves downwardly with bar 115 to the back supporting position illustrated in fig3 wherein the back support 110 is taut on the frame 100 the lateral seat edges 92 are then clamped into the slots 91 on the chair frame via the clamp bars for wedges 94 to secure the cloth seats 93 to the rolling chair frame the motor 119 is then reversely operated to drive the gear 121 and shaft 120 to raise the sub frame 49 and track assembly 50 and chair 40 and person 32 supported thereon to a position removed from the bed to the position illustrated in fig3 a referring now more particularly to fig3 the rolling chair 40 with the patient 32 thereon is then forwardly moved the rollers 103 will initially ride on the upper surface 73a of the rear tracks 73 and the front rollers 108 will ride on the upper surface 72a of the front track surfaces 72 when.