GB596212A - Improvements in artificial arms - Google Patents

Abstract

596,212. Artificial wrist appliances. OTTERMAN, J. Sept. 28, 1945, N‹. 52/46. Divided out of 596,206. [Class 81 (ii)] An artificial arm wrist fitting comprises an inturned flange 24 having a side opening 125 into which may be slid the base plate 25 of an artificial hand or other appliance 26, and a projecting lever 42 movable to actuate a drive member 29 and a locking bolt 38 (both displaceably mounted) in and out of engagement with the hand. The lever 42 is attached to the sleeve 41 in which the bolt 38 is retained by a spring 52. The sleeve slides outside the guide 37 and has a flange 45 which, cooperating with a flange 146 formed on a pin 71. restrains a sleeve 66 from sliding forward on a tube 65 under the action of the spring 74. The pin 71 has a key 72 sliding in a slot 73 in the barrel 30 in which the drive member 29 is retained by a spring clip 31 and pressed by a spring 48. The drive member 29 has parallel pins 33 co-operating slidably with flats formed on a rotating shaft 23. The sleeve 66 is keyed to the tube 65 which is rotated as described in Specification 596,206 by flexion of the elbow joint to provide pronation and supination movement for the appliance. Recesses are so placed in a longitudinal slot in the casing in which the lever 42 slides that in succession : (1) the barrel 30 enters a central recess 49 in the base plate of the appliance so that the latter cannot be removed ; (2) the drive member 29 engages a driver 27 for the appliance, while the pin 71 enters a hole 75 in the base plate so that the appliance may be rotated by the tube 65 ; (3) the lock bolt 38 enters the hole 54 in the base plate to prevent rotation while the flange 45 actuates a bell-crank lever 76 which pushes back the flange 69 of sleeve 66 and disengages the pin 71. Rotating the lever 42 in a lateral slot about the wrist axis rotates a flange plate 60 provided with a longitudinal slot only, corresponding to the casing. Cam surfaces on the cams 62 and studs 64 then co-operate to force out a pressure plate 55 against the action of springs mounted between the end plate 35 and the heads of bolts 59 mounted on the pressure plate, so as to firmly clamp the base plate 25. In a modification, Figs. 3-5, the tube 65 and associated mechanism are omitted, and an abutment on the sleeve 41 co-operates with an abutment on the barrel 30. The drive shaft may be rotated as described in Specifications 596,206 or 596,213 or according to a further modification, Figs. 16-17, by a cord and pulley system. A push rod drive system may also be used. Specification 596,209 also is referred to.