Prosthetic suspension mounting assembly
A prosthetic suspension-mounting system which employs an improved flathead bolt and socket centering cup combination for securement of an amputee-limb enveloping liner within a prosthesis. The liner has a strap fixedly attached on the bottom end of the liner by a flathead bolt. The mounting system also includes a containment socket for seating the liner in the prosthesis using the head of the flathead bolt as a bearing surface against a floor of the socket. The containment socket has a slot there through at a position corresponding to the strap of the liner. The socket is provided with a disk-shaped recess having a flat floor, and the liner is provided with a distal flathead bolt having a flat head to provide a direct bearing surface against the floor of the socket. This provides a delimited bearing surface to keep the liner substantially centered within the prosthesis while still affording a lateral degree of freedom to avoid concentration of lateral forces.
1. An anchoring system for securing a prosthetic liner inside a socket, comprising:
a centering cup seated in said socket for seating said liner thereon, said centering cup comprising a disk formed with a concave top rim encircling a circular recess, said circular recess having a flat recessed circular floor having a first diameter; and
a weight-bearing flathead bolt screwed into a distal end of said liner and having a flat circular head of a second diameter at least 50% smaller than said first diameter, the flat head of said bolt slidably contacting the flat recessed circular floor of said circular recess and constrained to slide thereon within a limited degree of sliding freedom limited to said first diameter.
2. The anchoring system of claim 1 , wherein said liner comprises a lower attachment strap attached at a lower distal end.
3. The anchoring system of claim 2 , wherein said centering cup comprises a sidelong groove passing through said centering cup into said circular recess for passing said lower attachment strap.
4. The anchoring system of claim 3 , wherein said liner comprises an upper attachment strap attached above said lower attachment strap.
5. The anchoring system of claim 4 , wherein said upper attachment strap is attached to said liner by a grommet-post.
6. The anchoring system of claim 5 , wherein said grommet-post comprises at least two flat rim components sandwiching a first end of said upper fastening strap.
7. The anchoring system of claim 4 , wherein said upper attachment strap comprises a hybrid weave hook and loop material.
8. The anchoring system of claim 4 , wherein said upper attachment strap comprises a buckle.
9. The anchoring system of claim 8 , wherein said buckle is a rectangular, stirrup-type stainless fixture.
10. The anchoring system of claim 3 , wherein said centering cup includes a roller pin mounted proximate said sidelong groove therein.
11. The anchoring system of claim 10 , wherein said roller pin is suspended above the flat recessed floor by opposing walls of said circular recess.
12. The anchoring system of claim 10 , wherein said lower attachment strap is adapted to pass under the roller pin, through the sidelong groove and through an aligned attaching member slot.
13. The anchoring system of claim 1 , wherein said centering cup is a plastic member.
14. The anchoring system of claim 1 , wherein said liner further comprises a threaded socket assembly fixedly attached to the lower distal end of the liner and to which said flathead bolt is attached.
15. The anchoring system of claim 14 , wherein said threaded socket assembly comprises a threaded metal screw socket embedded in a concave rubber cup.
16. The anchoring system of claim 1 , wherein said second diameter is within a range of from one-half to one-fifth of said first diameter of said circular recess is at least two times the size of the flat head bolt.
17. The anchoring system of claim 1 , wherein said centering cup comprises a plurality of radially-spaced grooves for indexing the centering cup within said socket.
18. The anchoring system of claim 1 , wherein said flathead bolt being configured to bear against the flat floor of said recess comprises a head of said flathead bolt directly engaging said flat floor of said recess when said liner is inserted into said socket.
19. An anchoring system for securing a prosthetic liner inside a socket, comprising:
a centering cup seated in said socket for seating said liner thereon, said centering cup comprising a disk formed with a concave top rim encircling a circular recess, said circular recess having a flat circular recessed floor of a first diameter defining a circularly-constrained bearing surface; and
a weight-bearing flathead bolt screwed into a distal end of said liner, said flathead bolt having a flat circular head protruding from said liner and configured to bear weight against the flat floor of said recess, said flat circular head having a second diameter at least 50% smaller than said first diameter, the flat circular head of said bolt slidably contacting the flat circular recessed floor of said centering cup recess and constrained to slide thereon within a limited degree of sliding freedom limited to said first diameter.