US616873A - Artificial leg - Google Patents

Description

9 9 h 3 m a l d e .I n e t a P S W E R D N A W 2% 7 mm B 0 N ARTIFICIAL LEG.

(Application filed Nov. 1, 1895.)

INVENTOR BY m, M

ATTORNEY.

(No Model) WITNESSES.

THE Nouns PETERS co. PHOTO-LYING" WASPHNGTDN. n. c.

WILLIAM ANDREWS, OF LOIVELL, MASSACHUSETTS.

ARTIFICIAL LEG.

SPECIFICATION forming part of Letters Patent No. 616,873, dated January 3, 1899.

Application filed November 1, 1895. Serial No. 567,569. (No model.)

T0 at whom it may concern.-

Be it known that 1, WILLIAM ANDREWS, a citizen of the United States, residing at Lowell, in the county of Middlesex and Commonwealth of lllassachusetts have invented a certain new and useful Improvement in Artificial Legs, of which the following is a specification.

My invention relates to artificial legs, and comprises an improved core for the foot, means of attaching the core to the shell or leg proper, means of giving a greater lightness and elasticity to the heel, and means of attaching the hamstring to the leg and thigh-piece to limit the forward motion of the leg with reference to the thigh.

In the accompanying drawings, Figure 1 is a side elevation of a leg provided with my improvements Fig. 2, a rear elevation of the same; Fig. 3, a vertical section of the foot and lower part of the leg through the center of the heel and great toe Fig. l, a rear view of the plate to which the hamstring is attached; Fig. 5, a vertical section of said plate on the line 5 5 in Fig. at Fig. 6, an isometric view of parts of toe-springs and envelop, the cords of the upper spring being exposed.

The lacer or thigh-piece A to receive the thigh and provided with buttons at to engage a strap which in practice is passed over the shoulder of the wearer, the metallic hinge B, connecting said thigh-piece to the shell or leg proper, C, and said shell are of the usual construction except as hereinafter stated.

The core D of the foot is of selected wood having a natural bend or crook, such that the grain of the wood is as nearly as possible parallel with the curved central line of the core from end to end thereof,which makes it almost impossible to break the core in use. The upper end of the core is reduced at (Z to form a tenon or stud which enters a corresponding hole or mortise o in the lower end of said shell 0, and this hole or mortise 0 maybe continuous with the hollow or cavity 0 of said shell, as shown in Fig.3. The tenon is retained in and prevented from turning in the shell G by glue and by one or more dowel-pins (1 The core D is provided with a shoulder (1 which is in contact with the lower end of the shell; but the circumference of the core at said shoulder, including the shoulder, is slightly less than that of the lower end of the shell.

Over the core D is arranged an elastic covering E, of soft flexible rubber or other suitable flexible plastic material, having the external shape of the natural foot and having its external surface continuous with that of the socket O, the top of said covering being of the thickness of the space between the outer edge of the shoulder d and the outside of said socket.

Within the covering E is arranged a toespring F, similar to what is shown in my pending application, Serial No. 429,281, filed April 15, 1392, in the respect that said spring extends from a point above the core beyond the toe of said core and from a point below said core beyond the toe of said core, and no claim is made herein to this peculiarity of said spring; but the toe-spring shown herein, in addition to the cords f arranged at intervals and extending lengthwise of said spring, has other cords f arranged at intervals transversely of the cords f and preferably interlaced with said cords f, all said cords being embedded in rubber, which becomes hard when vulcanized, and the interstices between said cords form a spring, being large enough to allow them to be penetrated by the said rubber when in its plastic state before vulcanization, so that said rubber is a continuous piece on both sides of and between all said cords. The additional cords f prevent the hard rubber from being broken between the cords fand said last-named cords from spreading apart. The construction of the spring is best shown in Fig. 6. The number of such springs F used will depend on the weight of the person and the strain to which the foot is likely to be subjected, a laborers artificial foot requiring more such springs than would be necessary in the foot of a man who merely uses his foot in walking. Four springs F are shown in Fig. 3, with a layer of soft rubber between each spring and the next and another layer of soft rubber between the upper spring 'andthe core-that is, all the springs F are embedded in the soft rubber of the envelop E.

Within the heel portion of the envelop E below the core is formed an'air space or cell G, which serves to lighten the foot and to increase the spring action thereof and to yield when the foot is inclosed in a tight shoe, as a solid rubber heel could not do. The airspace G obviates the necessity of an anklejoint by allowing the heel to compress and contract when the weight of the wearer is put upon the heel in walking.

The attaching-plates H II are substantially alike, the upper one II being longer to give a greater bearing on the lacer or thigh-piece, which being of soft sheet material, as leather, does not afford as good an opportunity for securing said upper plate as is oifered by the rigid wooden socket G, to which the lower plate II is fastened by screws it, while the upper plate is secured by rivets h. Each attaching plate is of sheet metal, laterally curved to fit the thigh-piece or socket, as the case may be, and is inverted with respect to the other, and each is offset at 7L2 7& near its straight end or end nearest the other attaching-plate to allow the lacing I or hamstring to pass between the offset portion of such plate and the thigh-piece or socket, said lacing pass ing back and forth through holes 71* 7L5, with which said offset portions respectively are provided, and being tied at the ends, as shown in Fig. 1, so that the greatest distance of the plates II II may be limited and the forward swing of the socket with reference to the thighpiece may be made to correspond to the action of the natural leg. The lacing I is preferably of rawhide.

To prevent wearing the clothing, the attaching plates. are covered with leather stitched at h at the edges, as indicated by dotted lines in Fig. 4, and these edges of the leather allow of the upper plate II being secured to the thigh-piece by stitches as well as by rivets. The holes h" 7L5 are protected by eyelets 7L7, as shown in Fig. 4, to prevent said plates from cutting the lacing.

I claim as my invention- 1. The combination of the core, an elastic covering therefor of the external shape of the natural foot, and a toe-spring, arranged in said covering and extending from a point in front of said core above and below said core and consisting of cords, arranged at intervals in a layer and extending longitudinally and transversely of said spring and embeddedin hard rubber, said hard rubber covering said layer on both sides and filling the interstices between said cords, as and for the purpose specified.

2. An artificial foot, consisting of an inelastic core and an elastic portion in the outline of the foot and inclosing said core, the heel of said elastic portion having within it an air space or cell; substantially as set forth.

3. The combination of the lacing and the attaching-plates, arranged wholly below the upper end of the socket and above the lower end of the thigh-piece and curved laterally to fit the thigh-piece and the socket and offset at their adjacent ends to leave spaces between said plates and said thigh-piece and socket, said plates being provided with eyelets to receive said lacing, as and for the purpose specified.

In witness whereof I have signed this specification, in the presence of two attesting witnesses, this 28th day of October, A. D. 1895.

WILLIAM ANDREIVS.

\Vitn esses ALBERT M. Moons, JAMES JACQUES.

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