Untitled record

Application filed February 12, 1892. Serial Wo. 421,301. (Wo model.)

To all whom it may concern:

Be it known that I, Homer F. Ehle, a citizen of the United States, and a residen t of the city of Helena, county of Lewis and Clarke, State 5 of Montana, have invented a new and useful Improvement in Artificial Limbs, of which the following is a specification.

The object of my invention is to secure a natural movement for an artificial foot, ease ro of manipulation of the same by the wearer, and absence of shock or jar to the stump in walking by a construction which- shall combine simplicity with strength and durability.

The drawings and specification describe 15 the invention asappliedto an amputation between the knee and ankle; but it is equally applicable to all other amputations above the ankle.

Reference is made to the accompanying 20 drawings, which are made a part of this specification, in which similar letters refer to similar parts in all the figures.

Figure 1 is a side elevation of the whole mechanism, including thigh-socket, stump25 socket, and artificial ankle and foot. Fig. 2 is a vertical section of the ankle and foot lengthwise with the foot. Fig. 3 is a vertical section of the ankle and foot at right angles to the line of the foot. Fig. 4 is a vertical section of the metal joint in the ankle. Fig.

is a vertical section of the stump-socket looking at it from the rear. Fig. 6 is a vertical section of the stump-socket looking at it from the side.

The metal supporting-braces A A—one upon each side—are riveted or otherwise firmly attached to the thigh-socket B, the stump-socket C, and the ankle-piece D, and' work with pivot-joints A' at the knee. The ankle-piece D, which is preferably made of wood, is hollow throughout part of its length D', and is strengthened near each extremity by wrapping with wire cZ. The foot is composed of three sections. The lowest E is made 45 of felt and is from two to three inches thick, according to the size of the foot. The middle section E' is preferably made of wood and is placed so as to slope backward at an angle of above five degrees from the horizontal, and the uppermost section E² is made of sponge rubber with its upper and exposed surfaces of hardened rubber to resist wear. These sections are firmly glued together and fine wire s is wrapped about the lower and middle sections near the heel. The foot is attached to 55 the ankle-piece D by a metal knuckle-joint consisting of a cylinder F, solid in its central portion F' and hollow at its ends. The bolts f f are firmly screwed into this central part F', and passing up through the apertures in 60 the base of the ankle-piece D are secured in the hollow D' by the nuts/'/'. The bolts g g are screwed into the pintles G G,which work in the hollow ends of the cylinder F, and passing through the slots g' g' pass through the 65 wooden section E' and are secured on its under side by nuts g² g². Upon the cylinder F are two V-shaped flanges F², which work in corresponding grooves E³ in the wooden section E', thus preventing any lateral movement 70 in the joint.

In the back of the ankle-piece D is an aperture D², through which passes the eyebolt h, secured at its upper end by a nut h' and having an eye Zrat its lower extremity. An- 75 other eyebolt J passes up through the wooden section E', being secured at its lower end by the nut j' and having an eye j² at its upper extremity. A silk cord K is secured to the eye h², and passing through the aperture I in Sc the rubber E² and having some slack when the foot and ankle-piece are at right angles is secured to the eye j². A flat steel springs is fastened to the under side of the front end of the wooden section E' by the bolts m' and 85 runs down, conforming to‘the shape of the foot over the instep and near/’ to the toe of the felt section E. The stump-socket C is padded with any soft elastic material, preferably with sponge rubber covered with soft 90 leather on its inside surface, as seen at n, wherever the bearing of the stump may come’ according to shape and size of stump, and is an important feature in conjunction with the construction of the foot in securing ease and 95 lack of shock to the stump.

The parts described as being made of wood may be made of any other suitable material possessing strength, firmness, and lightness, as aluminium. The rubber section E² is made ico

487,697 about one-fourth inch thicker than the space between the base of the ankle-piece D and the wooden section E', so that when the anklepiece and foot are secured together there is a 5 one-fourth inch compression of the rubber

E², which will take up any play caused by wearing away of the rubber and give a firmer elasticity. The base of the ankle-piece D and the upper surface of rubber E² are so shaped io as to give a greater thickness of rubber in front of the ankle-joint, where most of the pressure will be, than behind.

The silk cord K is designed to act only so as to receive the strain in case of an unusual 15 weight being thrown on the toe and thus to prevent wrenching and breaking of the anklejoint.

The spring m is not confined to a flat spring, but maybe of any suitable shape or construcso tion, the object being simply to exert a downward pressure from above on the toe to prevent the toe turning up after the elasticity of the felt is weakened.