US21289A - Attachment to abtiitcial legs - Google Patents

Description

UNITED STATES PATENT FID..

OLIVER DAVID IVILGOX, OF ELMIRA, NEW YORK.

ATTACHMENT 'IO ARTIFICIAL LEGS.

Specification of Letters Patent No. 21,289, dated August 24, `1858.

. To all w/wm t may concern:

Be it known that I, OLIVER DAvm WILCOX, M. D., of Elmira, in the county of Chemung and State of New York, have invented a new and useful Improvement in Artificial Legs; and I do hereby declare that the following is a. full, clear, and exact description of the same, reference being had to the accompanying drawings, making part of this specification, in which- Figures 1, and 2, are longitudinal sections of an artical leg with my improvements.

Similar letters of reference indicate like parts in the two figures.

This invention consists, in providing for the adjustment of thesack which forms part of the subject matter of Letters Patent granted to me SepteSOth, 1856, to adapt it to the condition of the stump, by means of straps and buckles applied substantially as hereinafter described.

To enable others skilled in the art to apply my invention, I will proceed to describe its construction and operation.

A, is the thigh piece; B, the leg, and C, the foot, all made o-f wood, hollow and as light as possible. These may be fitted t0- gether with mortises and tenons or with flange joints, in the same manner as in artificial limbs heretofore used.

D, is a short lever of the rst order, having one arm secured rigidly by screws a, a, or otherwise, to the thigh piece. This lever passes through a slot Z in the top of the leg which is hollow, and has for its fulcrum the knee-joint pin b. E is another short lever of the irstorder, having one arm secured rigidly to the foot by being driven tightly thereinto or by other means, having for its fulcruin the ankle-joint pin c, and having its other arm extended upward into the leg.

F, is a lever of the first order, of nearly the full length of the leg B, arranged within the leg, having for its fulcrum a pin (l, which is stationary within the leg, and having its lower arm somewhat shorter than the upper one. The upper arm of this lever F is connected with the lower arm of the lever D, by a link c, which makes as nearly as possible a rectangular connection between said levers. The lower arm of the said lever F, is forked to receive a small sliding block g, which is pivoted to it by a pin n, and which is fitted to slide in a slot in the upper part of the lever E. j l

j, is a block of hard wood secured in the front of the slot Z, in the top of the leg and fitted with a piece of india-rubber 7a, which is faced with a piece of leather. This block cushioned with india-rubber serves as a stop to the upper arm of the lever D, tostiffen the knee joint when it is straightened.

m, my, are two pieces of leather, one attached to the thigh piece A, and the other to the leg B, to cover the back of the kneejoint. These pieces are laced together b-y a lace n, which causes such a degree of tension to be produced on them, as the joint is straightened, as to prevent the lever D coming violently in contact with the stop, j, R.

Gr, is a spring applied within the foot and secured thereto in such a manner that the lower part of the front of the leg will be caused to press upon it by the fleXure of the ankle joint, and thus give elasticity to said joint in stepping.

The operation of the levers D, E, F, is as follows As the knee is flexed by moving Y it forward in walking, the lower and shorter arm of the lever D by means of its link connection e, throws forward the upper arm of the lever F, and throws back the lower end of the latter, which by its slot and slide connection with the lever E, causes the foot to move from the ankle oint and the toe to be elevated relatively to the leg so that it may clear the ground when the foot is raised therefrom and moved forward. The raising of the toe is continued by the flexure of the knee till the point of connection of the link e, with the lever D, passes in front of the knee-joint pin It is, however, only in sitting down, and not in walking, that the flexure is suficient for this; but in walking, the iieXure is suicient to cause the elevation of the front part of the foot .to such a degree as to cause the spring Gr, to be considerably compressed by the lower part of the leg; and when the foot is raised from the ground, the force of said spring is exerted in throwing down the foot and transmitted from the foot through the levers E and F, to throw the foot and leg forward from theknee-joint.V

Though before the foot is brought to the ground the spring Gr is relieved, the continued forward motion of the leg and foot from the knee joint, produced by the voluntary motion of the wearers thigh causes the levers D, F, E, to operate in a manner the reverse of what they did during the act of iexing the knee, and thus to move the toe downward to a position relatively to the leg to come at to any ordinary surface of ground when it is set down. This connection of the foot, leg, and thigh produces a very close imitation of the movements of the natural leg.

H, is the sack Which receives the stump of the natural limb. When this is fixed, some diilculty is found in making it produce an equal pressure on all parts of the stump, which is very necessary to the comfort of the wearer; and again, nearly all stumps continue to shrink so that they settle down in the socket of the thigh piece A, and consequently the sack requires to be raised from time to time. For this purpose I suspend the sack from several straps p, p, Which pass l Y O. D. WILCOX.

Vitnesses:

S. C. REYNOLDS, R. KING.

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