GB347325A - Improvements in or connected with artificial limb joints - Google Patents

Abstract

347,325. Artificial limb joints. BLATCHFORD, C. D. W. and BLATCHFORD, W. A. D., 90, Clapham Road, Stockwell, London. Feb. 3, 1930, No. 3663. [Class 81 (i).] An elbow or knee joint for artificial limbs of the type in which the lower arm or leg member is movable into various adjusted positions in a vertical plane and locked or released therefrom, comprises upper and lower limb members connected by a transverse shaft divided into two portions adapted to telescope one within the other, means associated with one portion for rotating the shaft and moving one limb part relative to the other, and locking means comprising a bolt or pin, to releasably lock said limb part. As applied to an elbow joint, the ring member 1, rotatably mounted in or on the upper arm bucket 2 are adapted to be locked in any desired position, has lugs 3, 4 provided with bearings 5, 6 for the shaft 7, on the angular or squared ends 8 of which straps 9, carrying the forearm, are mounted. The shaft is divided into two portions 15, 16, connected by a cross-pin 20, the portion 16 being formed with a quadrant or disc 17 having apertures to receive a locking-bolt or the like 19. A pin or extension 21, provided on an enlarged portion of the shaft 7, engages a rubber or other stop 22 on the lug 3 and limits the forearm movement. The lug 4 is extended to form a casing 23. A tubular bearing 24 for the bolt or pin 19 is provided in this casing. The grooved sector or quadrant 25 provided on the sector 17 is connected to an appendage 26, passing over a roller 27, by which the shaft 7 can be rotated.. A closure screw or cap 28 for the casing 23 provides an abutment for the spring 29 which bears against the base of a recess 30 in the bolt 19. A cam 34, secured on a rotatable shaft 35, engages a lug 31 on the bolt as described in copending application 344,429, and on the other end of the shaft 35 is rotatably mounted the casing of a free-wheel clutch or the like of the type described in copending application 344,430, in which a pair of spring-pressed balls or the like contact with the shaft, and are arranged to clutch the same when the casing is moved by means of an appendage against the action of a coiled spring, secured at its ends to the free-wheel casing and to the casing 23 respectively, and to declutch when the appendage is released. The arrangement is such that the locking bolt 19 is only moved out of locking position when the cam moves through substantially 90‹, and returns to its locked position if the rotation is less. A casing 41 detachably secured to the lugs 3, 4 may be fitted.