GB385079A - Improved construction of wrist joint for artificial arms - Google Patents

Abstract

385,079. Wrist joint for artificial arms. STEEPER, H., Queen Mary's Hospital, Roehampton Lane, and HOARE, D. C., 5, Kenwyn Road, Clapham, both in London. Nov. 14, 1931, No. 31582. [Class 81 (ii).] In a wrist joint of the kind wherein a plate on the hand or tool-carrying portion has a central grooved stem which is inserted into a tube on a plate secured to the forearm and held by a spring catch engaging the groove, the hand or toolholding portion being rotatable and held in any adjusted position by springs, the whole being locked by a separate device, the hand or like portion 16 has a projecting pin 20 adjacent the grooved stem 17 and a ring of holes 21 surrounding both, the plate 22 on the forearm 23 being formed on its inner side with a central tubular portion 24 having a slot 27 part way across it, which slot is engaged by the curved edge 31 of a spring-controlled lever 29 pivoted to a pillar 28 on the plate. An angled, lugged, or turned end 32 of the lever 29 rides in a notch 33 of a tubular portion 25, at right-angles to the portion 24 and carrying a controlled plunger 34 having a rounded or angled end for contacting the end 32 of the lever and projecting through the forearm. A spring-controlled push-rod 39 is positioned in another tubular portion 26 of the plate and carries a pin 41 and cam 43 operable by a knob 44 for further locking the hand or like portion. A ring-plate 46 surrounds the tubular portion 24 of the plate 22, on the outside thereof, and is provided with holes 50 for accommodating spring-pressed plungers 52 which act on said ring-plate to press it beyond the plate 22.