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Gelineau, Roger; |
Ankle prosthesis with angle adjustment

An ankle prosthesis for attachment to a foot prosthesis and an upper leg portion includes a swivel connection allowing adjustment of the angle of a longitudinal axis of the foot prosthesis relative to a vertical axis of the leg portion. The adjustment is provided by a pair of plates lying in a common plane containing the longitudinal axis and the vertical axis which can rotate relative to one another and each includes a series of radial ribs allowing adjustment through predetermined angles.


I claim:
1. A leg prosthesis for attachment to a remaining leg portion of an amputee patient comprising:
a foot prosthesis defining an elongate body having a lower surface for engaging the ground, an upper surface generally parallel to the lower surface and two generally upstanding side surfaces each on a respective side of the body so that the body is shaped to simulate a foot and to receive a shoe of the patient for application of pressure from the leg prosthesis to the ground through the shoe;
an upper coupling for attachment to the remaining leg portion;
and an ankle prosthesis located between the foot prosthesis and the upper coupling, the ankle prosthesis comprising:
a lower mounting bracket attached to the upper surface of the foot prosthesis and having a first swivel element standing upwardly therefrom;
an upper mounting portion for attachment to the upper coupling and having a second swivel element mounted thereon and extending downwardly therefrom for co-operation with the first swivel element;
the swivel elements defining co-operating abutment surfaces lying in a vertical plane longitudinal of the foot prosthesis and located between the side surfaces;
the swivel elements being mounted for relative rotation about an adjustment axis at right angles to the vertical plane;
each of the abutment surfaces having a plurality of ribs thereon, the ribs being raised in a direction longitudinal of the adjustment axis toward the other of the abutment surfaces and the ribs extending radially of the adjustment axis at angularly spaced positions therearound;
the ribs of the abutment surface of the first swivel element being arranged to intermesh with the ribs of the abutment surface of the second swivel element;
and means for clamping the abutment surfaces of the swivel elements together to hold the raised ribs in an intermeshed relationship to maintain the swivel elements against said relative rotation at a selected angle around the adjustment axis;
the clamping means being temporarily releasable to a distance to release the ribs from said intermeshed relationship to allow adjustment rotation of the first swivel element relative to the second swivel element through an angle which is a whole number multiple of the angular spacing of the ribs.
2. The improvement according to claim 1 wherein the ribs of each of the abutment surfaces are triangular in cross-section.
3. The improvement according to claim 1 wherein each abutment surface has an inner circular portion surrounding the adjustment axis which is smooth so as to be free from the ribs and an outer annular portion which is covered by the ribs.
4. The improvement according to claim 2 wherein each abutment surface has an inner circular portion surrounding the adjustment axis which is smooth so as to be free from the ribs and an outer annular portion which is covered by the ribs.
5. The improvement according to claim 1 wherein the lower mounting bracket comprises a substantially planar mounting flange with the first swivel element integrally formed with flange and standing upwardly therefrom on one side face of the flange with the abutment surface lying in a plane at right angles to the mounting flange with the plane intersecting with the mounting flange along a center line thereof.
6. The improvement according to claim 1 wherein the upper mounting portion comprises a substantially planar mounting flange with the second swivel element integrally formed with flange and standing upwardly therefrom on one side face of the flange with the abutment surface lying in a plane at right angles to the mounting flange with the plane intersecting with the mounting flange along a center line thereof and a sleeve mounted on the face of the flange opposite to the second swivel element.
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