GB1245922A - Improvements in or relating to the control of wheel-chairs by physically disabled persons - Google Patents

Abstract

1,245,922. Controlling wheel-chairs. SAUNDERS & DUDLEY Ltd. 23 Dec., 1968 [21 Sept., 1967], No. 31511/67. Heading B7H. A motorized wheel-chair has left and right hand wheels 1, 2 independently driven by respective electric motors 3, 4 which are controlled through flexible control-transmitting means extending to the head region of an occupant sitting in the chair so as to be selectively operable by an occupant who is paralysed from the neck downwards. In Fig. 1 a multiple-core electric cable 8 extends from a plug and socket connection 7 with a relay control box 6 for the motors 3, 4 to a control device actuated by a movable headrest 10. The headrest 10 is flexibly connected by a damping spring 16 to a movable front plate 13 which is connected by a ball and socket joint 12 to a fixed back plate 9 and is resiliently urged into parallelism with the back plate by a spring 14. Four switches are mounted at 90-degree intervals around the back plate 9 for actuation by the front plate 13 and are so arranged that upward tilting of the headrest 10 caused forward drive of the chair by both motors 3, 4, downward tilting causes rearward drive by both motors, and tilting to the left or right turns the chair in the corresponding direction by simultaneous forward and rearward operation of the respective motors. The switches may be micro-switches 17 or may be reed switches 18 each comprising a pair of contacts within a glass tube, one of the contacts being mounted on a flexible reed so as to be actuable from outside the tube by a magnet 19. In an alternative arrangement, Fig. 3 (not shown), the cable 8 is connected to a control device comprising four reed switches which are carried by a flexible collar encircling the occupants neck and arranged for actuation by tilting the head. In Fig. 4, operation of the motors is controlled by diaphragm-actuated switches 30 from which flexible tubes 32 extend into the occupants mouth. The switches 30 are actuated by sucking or blowing into the tubes 32 operation of one motor only when turning being effected by blocking the end of one tube with the tongue. Saliva traps 33 in the tubes 32 are suspended from the occupants neck by a cord 34.