1. An environmentally friendly and easily compressed pyrotechnic delay composition, comprising:
a ternary mixture of B4C (boron carbide), NalO4 (sodium periodate), and PTFE (polytetrafluoroethylene);
which mixture has an inverse burning rate from about 1.3 to about 20.8 scm when pressed into a consolidated column.
2. The delay composition of claim 1, wherein the composition contains from about 8 to about 55 weight percent of the B4C; about 10 weight percent PTFE; and the balance NalO4.
3. The delay composition of claim 2, whereupon when consolidated at 376.6 MPa results in a % TMD of about 70% to about 100%.
4. The delay composition of claim 1, wherein the composition contains from about 8 to about 40 weight percent B4C fuel; about 10 weight percent PTFE; and the balance NalO4.
5. The delay composition of claim 1, wherein the B4C is carbon rich, containing from 19.0 to 21.7 weight percent C.
6. The delay composition of claim 1, wherein the B4C is 1500 grit, the NalO4 is \u2212325 mesh, and the PTFE has a typical bulk density of about 480 grams per liter and a mean particle size of about 17 microns.
7. The delay composition of claim 1, wherein the delay composition is relatively easily compressed to relatively high % TMD with relatively ordinary loading pressures.
8. The delay composition of claim 7, wherein the relatively high % TMD is from about 88 to about 98% TMD and the relatively ordinary loading pressures are from about 250 to about 500 MPa.
9. The delay composition of claim 1, wherein when the pyrotechnic delay composition can be consolidated with minimal wear on the tooling used for the consolidation.
10. The delay composition of claim 1, wherein composition has an inverse burning rate from about 7 to about 8.5 scm.
11. The delay composition of claim 1, which provides repeatable delays of from 7-8.5 scm when consolidated in a large pancake-shaped HHS aluminum delay housing.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A prosthesis for a total wrist and distal radioulnar joint replacement, comprising:
an ulnar brace member, including
a rod defining a proximal end and a distal end and a longitudinal axis: and
a ball mounted on said distal end for translation along said longitudinal axis relative to said rod; and
a radial brace member having a volar side, dorsal side, radial side, ulnar side, proximal side and a distal side, and defining a first ellipsoidal surface at its distal side that is wider in the radial-ulnar direction than in the volar-dorsal direction; wherein said radial brace member further defines a bearing surface which supports said ball for relative movement between the ball and the radial brace member; and
an articular member defining a second ellipsoidal surface that is slidably received by the first ellipsoidal surface, wherein one of said first and second ellipsoidal surfaces is concave and the other is convex.
2. A prosthesis as recited in claim 1, and further comprising a cover releasably mounted on said radial brace member, wherein said cover and said radial brace member together form a substantially spherical cavity which receives and rotationally supports said ball and secures said ball on said radial brace member.
3. A prosthesis as recited in claim 1, wherein said first ellipsoidal surface extends in the ulnar direction beyond the longitudinal axis of said rod.
4. A prosthesis as recited in claim 1, wherein said first ellipsoidal surface is concave and said second ellipsoidal surface is convex.
5. A prosthesis as recited in claim 1, wherein said radial brace member includes an elongated portion projecting in the proximal direction and defining a radius abutment surface, said elongated portion defining a plurality of laterally-oriented holes.
6. A prosthesis as recited in claim 5, wherein said laterally-oriented holes are threaded; and further comprising a plurality of mounting screws for mounting said radial brace member to a radius bone, each of said mounting screws having a head and defining locking threads at the head which are sized to be threaded into said threaded holes in said elongated portion.
7. A prosthesis as recited in claim 1, wherein said first ellipsoidal surface further has a distal edge defining a central recess in its volar side which forms a guide surface for receiving the median nerve and flexor tendons of the wrist.
8. A prosthesis as recited in claim 7, wherein said second ellipsoidal surface defines a recess aligned with the central recess in said first ellipsoidal surface.
9. A prosthesis as recited in claim 5, and wherein said radial brace member further defines a proximal convex surface which lies opposite said first ellipsoidal surface and is shaped and positioned to be received in the distal end of the radius bone without changing the overall length of the radius bone.
10. A prosthesis as recited in claim 3, and further comprising a cover releasably mounted on said radial brace member, wherein said cover and said radial brace member together form a substantially spherical cavity which receives and rotationally supports said ball and secures said ball on said radial brace member.
11. A prosthesis as recited in claim 10, wherein said first ellipsoidal surface is concave and said second ellipsoidal surface is convex.
12. A prosthesis as recited in claim 11, wherein said radial brace member includes an elongated portion projecting in the proximal direction and defining a radius abutment surface, said elongated portion defining a plurality of laterally-oriented holes.
13. A prosthesis as recited in claim 12, wherein said laterally-oriented holes are threaded: and further comprising a plurality of mounting screws for mounting said radial brace member to a radius bone, each of said mounting screws having a head and defining locking threads at the head which are sized to be threaded into said threaded holes in said elongated portion.
14. A prosthesis as recited in claim 13, wherein said first ellipsoidal surface further has a distal edge defining a central recess in its volar side which forms a guide surface for receiving the median nerve and flexor tendons of the wrist.
15. A prosthesis as recited in claim 14, wherein said second ellipsoidal surface defines a recess aligned with the central recess in said first ellipsoidal surface.
16. A prosthesis as recited in claim 15, and wherein said radial brace member further defines a proximal convex surface which lies opposite said first ellipsoidal surface and is shaped and positioned to be received in the distal end of the radius bone without changing the overall length of the radius bone.
17. A prosthesis as recited in claim 1, wherein said ulnar brace member is mounted on the ulna bone said radial brace member is mounted on the radius bone, and said articular member is mounted on at least one carpal bone of a patient, and wherein said ball and said bearing surface provide the same axis of rotation and the same alignment of the radius and ulna as the patient’s original natural radioulnar joint.
18. A prosthesis as recited in claim 16, wherein said ulnar brace member is mounted on the ulna bone of a patient, said radial brace member is mounted on the radius bone of the patient without changing the overall length of the radius bone, said articular member is mounted on at least one carpal bone of the patient: the patient’s median nerve and flexor tendons extend along the guide surface formed by the central recess on the first ellipsoidal surface; and said ball and said spherical cavity provide the same axis of rotation and the same alignment of the radius and ulna as the patient’s original natural radioulnar joint.
19. A prosthesis for a wrist joint replacement, comprising:
a radial brace member having a volar side, dorsal side, radial side, ulnar side, proximal side and distal side, and including a wall at said distal side which defines a first ellipsoidal surface and a distal edge, wherein the volar side of said distal edge defines a centrally recessed guide surface for guiding the median nerve and flexor tendons of the wrist; and
an articular member defining a second ellipsoidal surface slidably received by said first ellipsoidal surface, one of said first and second ellipsoidal surfaces being convex and the other being concave.
20. A prosthesis as recited in claim 19, wherein said articular member defines a volar recessed guide surface aligned with said centrally recessed guide surface.
21. A prosthesis as recited in claim 20, and further comprising:
an ulnar brace member including
a rod defining a proximal end and a distal end, and
a ball mounted to said distal end;
wherein said radial brace member defines a bearing surface which receives and supports said ball.