GB616942A - Improvements in or relating to artificial limbs - Google Patents

Abstract

616,942. Artificial limbs. EVANS, J., and PARKWOOD (ARTIFICIAL COMPONENTS), Ltd. Sept. 24, 1946. No. 28549. [Class 81 (ii)] The locking bolt and securing catch of a wrist for an artificial hand, of the kind comprising a base-plate on the hand having a grooved peg which is rotatably engaged by a securing catch on the arm fitting, and a locking bolt on the arm fitting to prevent the hand rotating when set in position, are operated by a single lever. The peg 5 of the hand member 3 is grooved at 7 to co-act with a catch 12, Fig. 5, on the arm fitting to secure them together rotatably. A ball catch consisting of three spring-pressed balls 10 on the arm fitting engaging a number of equidistant holes in the base-plate 1 of the hand 3 gives a frictional adjustment for the rotational setting of the hand. A bolt 18, mounted in the arm fitting parallel to the peg 5 engages one of the holes in the base-plate 1 to lock it in position. The bolt is pressed by a spring 20 into the locking position, and is unlocked by means of a lever 21 protruding through a bayonet slot in the arm fitting and secured in the top of the bolt 18. The inner end 24 of the lever 21 projects beyond the bolt 18, so that rotational movement of the lever 21 in the direction of the arrow A, Fig. 5, causes it to disengage the catch 12 and release the peg 5, thus releasing the hand from the arm fitting. There are, therefore, three positions of the lever 21 in the bayonet slot, the first in which the hand is locked against rotational movement, the second, a neutral position, in which the hand is free to rotate against the ball catch and a third in which the hand is completely released from the arm fitting.