Page:The making of a man (1902).pdf/32

 with thumb and finger through holes in back of leg for readily adjusting the length. For the knee spring a suitably protected heavy elastic web is slipped over end of the rod and adjusted from outside of leg with buckskin strings; as leg is flexed in act of walking, the rod is forced through the hickory bar, stretching the web and forcing the lower part of the leg forward in position for next step; when lower part of leg is flexed at right angles with the thigh, as in sitting, the pressure of spring is automatically released. This change simplifies the knee-joint construction, is lighter and more convenient of adjustment.

Figs. 262 and 263 illustrate a new knee joint for amputation below the knee. This is the latest and decidedly the most compact, lightest, and at the same time the best wearing joint that we have ever adopted, not excepting the ball-bearing joint, and is recommended in all cases.

Joints of medium weight are usually applied. A heavier joint of same pattern is used, however, when the wearer is unusually heavy or desires an extra strong joint and does not mind the additional weight. Let us see if we can describe the uniqueness of it, so that it will be understood.

The head of the joint is very thin (three-eighths of an inch), permitting the trousers to set smoothly; at the same time there is as much wearing surface as in an ordinary joint of twice the thickness. C is a phosphor bronze (the toughest of metal) taper bushing fitted into a taper hole. B is a taper bolt fitting a taper hole in the bushing; when drawn into place with screw A, the bushing is wedged into male joint head E tightly, so that it is practically a part of this male head. In swinging the leg the movement or wear is on the bolt B inside the cone bushing, giving as much 32