Patent US4721510A successfully refreshed from Google Patents.
US4721510A
Expired / Lapsed
US
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Artificial foot
Assignee: Vessa Ltd
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Filing: 1987-02-24
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Granted: 1988-01-26
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Expires: 2007-02-24
Abstract
Abstract A prosthetic foot comprises a hollow elastomeric cosmesis having a relatively large internal space, a keel of relatively stiff or rigid material, and a stiffener of glass reinforced plastics fitted between keel and instep region of the cosmesis. Front and rear snubbers extend from keel and front and rear stiffeners being portions of stiffener extend from under the keel with radiused ends resting on the sole of the cosmesis. During ambulation the stiffeners provide a primary path by which ground reaction is transmitted to the keel, but ground reaction bringing the stiffeners into contact with the snubbing means is transmitted to the keel via an overload path through the snubbing means.
Inventors
- 👤 John E. Cooper
- 👤 Alun Wilcox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:10
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/50; A61F2/60; A61F2/66; A61F2/02; A61F2/30; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30433; A61F2002/5001; A61F2/5044; A61F2002/5055; A61F2002/6614; A61F2002/6657; A61F2220/00; A61F2220/0025; A61F2220/0041
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
204 words
An artificial foot comprising in combination: a hollow flexible cosmesis having a sole formed with an instep region and a region spaced from the instep region that flexes relative to the instep region during ambulation; a keel member in the cosmesis having a lower region fixed to the sole at the instep region and having an upper region by which it is intended to be fixed to upper parts of the leg; leaf spring means having a basal region held to the keel member at the instep region of the sole and having a terminal region that rests on the deformable region of the cosmesis; and snubbing means extending from the keel member in cantilevered relationship thereto, said snubbing means being spaced below said cosmesis and being in spaced overlying relationship to the leaf spring means which is deformable into contact with said snubbing means by ground reaction, the stiffness of the leaf spring means being such that during ambulation the leaf spring means provides a primary path by which ground reaction is transmitted to the keel and that ground reaction causing the leaf spring means to contact the snubbing means is transmitted to the keel via an overload path through the snubbing means.
Claim 2
Dependent Claim
204 words
An artificial foot comprising in combination: a hollow flexible cosmesis having a sole formed with an instep region and a region spaced from the instep region that flexes relative to the instep region during ambulation; a keel member in the cosmesis having a lower region fixed to the sole at the instep region and having an upper region by which it is intended to be fixed to upper parts of the leg; leaf spring means having a basal region held to the keel member at the instep region of the sole and having a terminal region that rests on the deformable region of the cosmesis; and snubbing means extending from the keel member in cantilevered relationship thereto, said snubbing means being spaced below said cosmesis and being in spaced overlying relationship to the leaf spring means which is deformable into contact with said snubbing means by ground reaction, the stiffness of the leaf spring means being such that during ambulation the leaf spring means provides a primary path by which ground reaction is transmitted to the keel and that ground reaction causing the leaf spring means to contact the snubbing means is transmitted to the keel via an overload path through the snubbing means.
Claim 3
Dependent Claim
15 words
A foot according to claim 1, wherein the cosmesis is formed of an elastomeric foam.
Claim 4
Dependent Claim
27 words
A foot according to claim 1, wherein the keel is attached to a plate bonded to the instep region of the sole which is of increased thickness.
Claim 5
Dependent Claim
33 words
A foot according to claim 1, wherein the keel member and snubbing means are of substantially rigid material so that the snubbing means acts as a mechanical stop for the leaf spring means.
Claim 6
Dependent Claim
16 words
A foot according to claim 4, wherein the keel member and snubbing means are of metal.
Claim 7
Dependent Claim
48 words
A foot according to claim 1, wherein the keel member and snubbing means are of stiffly flexible material such that after the leaf spring means has contacted the snubbing means the leaf spring means and the snubbing means act in parallel to provide a progressively increasing resistive load.
Claim 8
Dependent Claim
20 words
A foot according to claim 1, wherein the basal region of the leaf spring means is spaced above the sole.
Claim 9
Dependent Claim
31 words
A foot according to claim 7, wherein the terminal region of the leaf spring means is curved away from the sole to define a radiused tip of the leaf spring means.
Claim 10
Dependent Claim
17 words
A foot according to claim 1, wherein the leaf spring means is of filament reinforced plastics material.
Claim 11
Dependent Claim
12 words
A foot according to claim 9, wherein the filaments are of glass.
Claim 12
Dependent Claim
21 words
A foot according to claim 1, wherein the region spaced from the instep region is a metatarsal region of the sole.
Claim 13
Dependent Claim
34 words
A foot according to claim 11, wherein the leaf spring means terminates before a toe region of the foot whereby at toe off the ground reaction is resisted only by flexion of the cosmesis.
Claim 14
Dependent Claim
54 words
A foot according to claim 11, wherein second leaf spring means and second snubbing means extend towards the heel of the cosmesis to provide load paths for ground reaction during the heel strike phase of ambulation, said heel being a second region of the cosmesis that flexes relative to the instep region during ambulation.
Claim 15
Dependent Claim
43 words
A foot according to claim 13, wherein the first and second leaf spring means are rated so that when the amputee is standing the centre of ground reaction is spaced from the heel by about one third of the length of the foot.
Claim 16
Dependent Claim
12 words
An artificial leg fitted with a foot as claimed in claim 1.
References Cited (Backward Citations)
US3766569A
Cited
US4328594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-25 | 1991-07-27 | 1992-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-25 | 1995-07-27 | 1996-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-25 | 1999-07-27 | 2000-01-26 | $7700.00 | Window Closed / Lapsed |