GB124570A - Improvements in Artificial Limbs. - Google Patents

Abstract

124,570. Danson, J. D. March 27. 1918. Limbs, artificial.-Comprises special pawl-andratchet gear for knee-joints forming a locking- mechanism of the general type in which the joint is locked when supporting the weight of the wearer and is free to rotate when the weight is thrown on the other leg. Fig. 1 shows one construction specially adapted for pylons, in which ratchet sectors 1 are fixed at each side of the thigh portion of the leg. When the calf portion moves downwards in the sleeve 6, owing to the weight being thrown on the limb, pawls 3 are pushed upwards into engagement with the sectors by sliding-rods 8 attached to the foot portion, and lock the joint against rearward movement. The pawls disengage by gravity or by spring action as soon as the pressure on the limb is relieved. Fig. 3 shows a modified construction in which the sleeve 6 carrying the pawl-actuating rods is fixed near the upper end of the calf portion of the leg, and the projection 15 moves relatively to the sleeve when the weight is thrown on the leg. Fig. 5 shows a further modification in which the pawlactuating rods 8 are made longer and carry the ankle pivot 17 at their lower ends. When the weight comes on the limb, the foot and ankle pivot move upwards in slots 21 on the calf portion to operate the pawls. The limb may be fitted with a bucket comprising a wooden base supporting a metal framework 22, 23, and 24, the whole structure being covered with papier mÔchÚ and lined with felt. The felt lining is turned outwards over the top of the metal ring 24 and secured by sewing down or other suitable means. The foot is provided with the usual front and rear springs, as shown in Fig. 5, and with a pivoted toe-piece, as shown in Fig. 4.