Patent CA-1124452-A (CA)
Inventor: SCHWEMMER LEONARD J
Filed: 1981-06-11
Granted: 1982-06-01
Abstract: ABSTRACT OF THE DISCLOSURE The present invention provides an ankle joint pros-thesis comprising (a) a first relatively inextensible component adapted to be connected with a leg member, said first relatively inextensible component havinq a front and a rear and a pair of opposed sides that extend between the front and the rear of the first component, the first component also having a first surface which is disposed between the opposed sides of the first component and between the front and the rear of the first component, at least a portion of the first surface extending from one side of the first component to the other side and having a concavely arcuate shape from front to rear; (b) a second relatively inextensible component adapted to be connected with a foot member, said second relatively inextensible component having a front and a rear and a pair of opposed sides that extend between the front and the rear of the second component, the second component also having a second surface which is disposed between the opposed sides of the second component and between the front and the rear of the second component, at least a portion of the second surface extending from one side of the second component to the other side and having a concavely ar-cuate shape from front to rear, the second component being spaced from the first component and the second surface being presented generally toward the first surface; (c) means defining a relatively inextensible pivot member that is disposed between and spaced from each of the first and second components, the pivot member being oriented to extend from side to side of each component and having at least one convexly arcuate surface, the arcuate portions of the first and second surfaces each being presented to and spaced from a convexly arcuate surface to the pivot member; and  (d) means for resiliently securing the pivot member to each of the first and second components, the securing means including (i) a first portion which is at least partially formed of elastomer and which secures the pivot member to the arcuate portion of the first surface, (ii) a second portion which is at least partially formed of elastomer and which secures the pivot emmber ot the arcuate portion of the second surface, and (iii) a third portion which is secured to at least one of the first and second components at a point behind the arcuate portion of the corresponding one of the first and second surfaces and which extends away from said at least one of the first and second components toward the other of said first and second components, the first and second portions of the securing means resiliently permitting and accommodating relative rotation between the pivot member and each of the first and second com-ponents so that the first and second components can rotate toward and away from each other about an axis that is disposed at least adjacent to and at least approximately parallel to a central  axis of the pivot member, the first and second portions of the securing means including spaced apart segments disposed to rotate toward each other without exerting compressive forces on each other over a range of motion of said first and second components, the third portion of the securing means resiliently limiting relative rotational motion of the rear of the first component and the rear of the second component toward each other, the relative extensibility of the first and second components and the pivot member being determined in comparison to the elastomer of the securing means.