US3874004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Symes ankle joint
Assignee: JE Hanger and Co Ltd
•
Filing: 1974-05-28
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Granted: 1975-04-01
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Expires: 1994-05-28
Abstract
Abstract The invention provides an artificial ankle joint particularly suitable for patients who have undergone the Symes amputation. An effective ankle pivot center is provided at substantially the natural position by the use of a pair of links pivoted to points on the metal sole plate of an artificial foot and points, spaced nearer together, on a stump socket.
Inventors
- 👤 Denis Ronald William May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:47
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/50; A61F2/60; A61F2/66; A61F2/6607; A61F2002/6614; A61F2002/6657
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
75 words
An artificial ankle joint comprising a metal sole plate within an artificial foot, the said sole plate carrying pivot bearings for a posterior upwardly and forwardly sloped swinging link and an anterior upwardly and rearwardly sloped swinging link, the said links being pivoted at their upper ends to posterior and an anterior lugs forming part of patient weightbearing structure, and a pre-compressed resilient stressrelieving control block located between the sole plate and the weight-bearing structure.
Claim 2
Dependent Claim
75 words
An artificial ankle joint comprising a metal sole plate within an artificial foot, the said sole plate carrying pivot bearings for a posterior upwardly and forwardly sloped swinging link and an anterior upwardly and rearwardly sloped swinging link, the said links being pivoted at their upper ends to posterior and an anterior lugs forming part of patient weightbearing structure, and a pre-compressed resilient stressrelieving control block located between the sole plate and the weight-bearing structure.
Claim 3
Dependent Claim
17 words
An artificial ankle joint according to claim 1 in which the weight-bearing structure is a stump socket.
Claim 4
Dependent Claim
26 words
An artificial ankle joint according to claim 1, in which the weight-bearing structure is a plate fitted to the lower end of a modular artificial leg.
Claim 5
Dependent Claim
56 words
An artificial ankle joint according to claim 1, in which the instantaneous centres of rotation of the joint, namely the intersection points of the axes of the two links, forms an inverted hyperbola which passes through the two lower pivot centres and through the locus of the effective ankle pivot at zero deflection of the joint.
Claim 6
Dependent Claim
20 words
An artificial ankle joint according to claim 1, in which the length of each link is less than 30 mm.
Claim 7
Dependent Claim
23 words
An artificial ankle joint according to claim 1, in which the pivot bearings on the sole plate are more than 100 mm apart.
Claim 8
Dependent Claim
22 words
An artificial ankle joint according to claim 1, in which the lugs on the weight-bearing structure are less than 80 mm apart.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |