GB237085A - Improvements in artificial limbs - Google Patents

Abstract

237,085. Marks, E. C. R., (Livingston Artificial Limb Co.). July 7, 1924. Limbs, artificial.-An artificial hand comprises jointed fingers and thumb with mechanism for bending the hand and rotating the wrist. The hand is connected to an artificial arm 1, 5 which is secured to the stump 2 by a socket or cuff 3 fastened by lacing 4 the members 1, 5 of the arm being pivoted together by a pin 6. The cuff 3 is also connected by straps 7 to a saddle 8 which is held in position by a strap 9 passing round the wearers' chest under the opposite arm. A strap 10 is connected to the front and rear portions of the strap 9 and passes over the corresponding shoulder. Finger and thumb operating mechanism. Each finger comprises three pivoted sections connected together by links 29, 32. The inner sections of all four fingers are pivoted on a rod 20 which comprises four sections slightly out of alignment with each other whereby the fingers radiate slightly as in the natural hand. The bending of the rod 20 to form the sections may be accomplished by means of notches 20<a>. The inner section of each finger is provided with a pivoted link 39 having a notch at its lower end which engages the flange of a cam 34 connected to a drum 37. The cams may be rotated to open and close the fingers by means of cords or lines 43. 44 passing round and fixed to the. drums 37. The cords from all the fingers are connected to a single pair of operating lines 49, 51, the closing lines being connected indirectly to the line 51 through pulleys 52, 54 and a cord 53 as shown in Fig. 11 whereby the movement of any one finger is arrested on contact with an object. The lines 49, 51 pass over pulleys 50, 55 on the saddle 8 and are connected to a band 56 secured to the sound arm, movement of which causes the fingers to open and close. The thumb is operated by mechanism similar to the finger mechanism and comprises cords 68, 69 passing round a drum attached to a cam 62 engaged by a link 64. The thumb sections are connected by a link 59. Hand-bending and wrist-turning mechanism. The hand is pivoted at 18 to the wrist 16 which is rotatable about a conical extension 70 on the arm, two rows of ball bearings being provided at 72, 75. The hand can be bent forwards by a sliding bar 79 jointed to the hand at 80, guided in a loop 81 on the wrist and slidable in a channel-shaped lever 82 pivoted at 83 to the wrist. The bar 79 is held in any position by a fixed pin 86 which engages notches in the bar and the wrist is held in any position by means of a pin 87 on the lever 82 which can be made to engage any one of a series of holes 89 in the extension 70. The bar 79 is provided with an operating knob 90 covered with a rubber &c. strap 91.