GB596209A - Improvements in artificial hands - Google Patents

Abstract

596,209. Artificial hands. HOBBS, E. W. Oct. 19, 1945, No. 27461. [Class 81 (ii)] An artificial hand comprises a base member, a number of digits pivoted thereon, a rotary operating member which acts on the digits to open or close them positively and irreversibly, and a compensating linkage connected to the digits, such that after the movement of any of the digits has been arrested, continued movement of the remainder is possible. As shown, the base member comprises a base 15 and a welded or riveted light alloy skeletal structure 16-20, and carries pivoted thumb 10 and fingers 11-14, the finger pivots being offset in natural anatomical relationship. A ring 35 arranged to fit on a wrist plate of an artificial arm such as described in Specification 596,206, carries a square shafted driver 37 adapted to transmit rotary motion to screw 33 working in nut 34. The longitudinal movement given to the screw is transmitted via trunnion block 41 to a saddle piece 43 pivoted to the thumb skeleton 53, and to a link 60, the upper end of which is pivoted to a lever 63. Movement of the latter is confined by end portions 64 sliding on rods 16. Further levers 67 are pivoted at each end of lever 63, and their movement is transmitted to the ends of the fingers through links 68, 77 connected to a steadying link 78 rotatably mounted on tube 71 on pivot 26. The lower part of each finger consists of a metal box 69 and a tubular bearing 72, the latter carrying a barrel 75 united to strips 73 constituting the base members of the upper part of the finger. Link 77, projecting through a slot 79 in bearing 72, is pivoted at 81 to the barrel. Strips 73 are encased by a plastic sheath 83 carrying a rubber pad 85, and then lower part of the fingers and the base part of the hand by metal gauze subsequently coated with plastic material. The thumb comprises a reinforced plastic structure stuck to the metal skeleton. The thumb and one or more of the fingers may be rigid, or may be adjustable manually in one or more positions. Specification 103,481, [Class 81 (ii)], also is referred to.