GB231264A - Improvements in or relating to artificial hands - Google Patents

Abstract

231,264. Laherty, E. Jan. 17, 1924. Limbs, artificial. - An artificial hand is constructed so that the fingers and thumb can be closed and opened by turning the wrist relatively to the upper part of the forearm, and the whole hand can be rotated without operating the fingers by rotating the whole forearm relatively to the upper arm. As shown in Fig. 1 the hand 5 is connected to a leather forearm portion 12 which is secured to the arm of the wearer by lacing 13. A sleeve 14 shown in Fig. 6 surounds the wrist and is provided with a groove 15 in which is situated a ring 16 rigidly attached to aluminium strips 22 which are secured to a strap 23 surrounding the forearm near the elbow. The sleeve 14 and ring 16 carry pulleys 18, 20 round which pass the finger operating cords 29, 36 which are fastened at their ends to the rear potion of the sleeve 14. The fingers are actuated by rotating the wrist relatively to the upper part of the forearm which is surrounded by the strap 23. This movement causes the sleeve 14 to rotate while the ring 16 is held stationary by the strips 22 thereby causing relative movement between the pulleys 18, 20 and a displacement of the operating cords 29, 36. The hand is turned without actuating the fingers by rotating the whole forearm whereby no relative movement is obtained between the sleeve 14 and strap 23 and ring 16. Fig. 10 shows a modification in which two rings 16<1>, 16<11> are situated on the reduced ends of a sleeve 14' secured to the wrist. The rings are connected by strips 22<1> to the band 23<1> which encircles the upper part of the forearm. The finger actuating cord 41 passes over pulleys 42, 43 on the ring 16<1> and sleeve 14' and is attached at 44 to the ring 16<11>. The finger actuating mechanism for the form of hand shown in Fig. 1 is shown in Figs. 2 and 4. Two series of cords 27, 23 are attached to the upper and lower surfaces of the outer sections of the fingers and thumb as shown at 26, 34 in Fig. 4. The cords pass over two series of pulleys 25, 24 and are brought together at the points 28, 35 whence the single cords 29, 36 pass to the exterior of the hand as shown in Fig. 1. Springs 32 are included in the lengths of the actuating cords. In the form of hand shown in Fig. 10 the fingers are of the coiled spring type and are each actuated by a single cord. All the cords are brought together to form the single cord 41.