Surgeon's Gigli saw and method

• US 4,709,699 A
• Filed: 08/06/1986
• Issued: 12/01/1987
• Est. Priority Date: 08/06/1986
• Status: Expired due to Fees

• Current Assignee: Fort Wayne Metals Research Products Corp. (Fort Wayne Metals, Inc.)
• Original Assignee: Fort Wayne Metals Research Products Corp. (Fort Wayne Metals, Inc.)
• Inventors: Michael, Mark S., Glaze, Scott A.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): Kartchner, Gene B.
• Application Number:
  US06/893,876
• Time in Patent Office: 482 Days
• Field of Search: 128/317, 128/305, 125/18, 125/21, 76/25 R, 76/101 R, 76/112
• US Class Current: 606/177
• CPC Class Codes: A61B 17/149 Chain, wire or band saws
• CPC Class Codes: B23D 61/185 Saw wires; Saw cables; Twisted saw strips
• CPC Class Codes: B23D 65/00 Making tools for sawing machines or sawing devices for use in cutting any kind of material
• CPC Class Codes: D07B 2201/2019 pressed to shape
• CPC Class Codes: D07B 5/007 comprising postformed and thereby radially plastically deformed elements
• CPC Class Codes: D07B 7/027 Postforming of ropes or strands

Abstract

A Gigli saw used by a surgeon to cut bones is constructed of a plurality of round wires which have been deformed in a coining stand so that they form one polygonal shape which in the preferred embodiment is square. This square strand is then twisted along its own axis in a given direction of lay. It is then heat-treated for stress relief and a plurality, such as three, of such strands are twisted together to form a cable. This results in a Gigli saw blade with many cutting edges formed at the edges of the polygon as each such edge is presented at the periphery of the cable. Preferably, the strands have a different number of twists from that of the cable, and are twisted in the opposite direction so that the cutting edges lie at about 5 to 15 degrees relative to the longitudinal axis of the cable. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

Claims

1. A surgeon'"'"'s Gigli saw comprising, in combination:

a cable comprising a plurality of strands twisted together in a first rotational direction;

at least one strand of said cable having been previously twisted along its own axis in the opposite rotational direction from that of said cable; and

each strand comprising a plurality of wires substantially coined together into a generally polygonal cross-sectional shape.

2. A Gigli saw as set forth in claim 1, wherein said cable comprises at least three strands.

3. A Gigli saw as set forth in claim 1, wherein said at least one strand has a different number of twists per inch from that of said cable.

4. A Gigli saw as set forth in claim 1, wherein said at least one strand has a greater number of twists per inch than said cable.

5. A Gigli saw as set forth in claim 1, wherein at least two of said strands have been previously twisted along their respective axes.

6. A Gigli saw as set forth in claim 1, wherein said polygonal shape of at least one strand is substantially square.

7. A Gigli saw as set forth in claim 1, wherein said polygonal shape of at least one strand has the exterior faces forming the polygonal shape meeting at edges with an interior angle in cross section not exceeding about 90 degrees.

8. A Gigli saw as set forth in claim 1, wherein said at least one strand has about twice the number of twists per inch of said cable.

9. A Gigli saw as set forth in claim 1, wherein each of said strands of said cable has been previously twisted along its respective axis.

10. A Gigli saw as set forth in claim 9, wherein each of said strands of said cable has been previously twisted in said opposite rotational direction from that of said cable.

11. A Gigli saw as set forth in claim 9, wherein each of said polygons is substantially a square.

12. A Gigli saw as set forth in claim 9, wherein each of said strands has about thirteen twists per inch.

13. A Gigli saw as set forth in claim 9, wherein said cable has about seven twists per inch.

14. A Gigli saw as set forth in claim 9, wherein said strands have been twisted to such an extend relative to the opposite twists of the individual strands that the strand edges where adjoining faces meet define cutting teeth extending at about 10 degrees relative to the axis of the cable.

15. A Gigli saw as set forth in claim 1, wherein the twist of said at least one strand relative to the twist of the cable establishes the edges of the polygon of said at least one strand at an angle of about 5 degrees to 15 degrees relative to the longitudinal axis of the cable.

16. The method of manufacture of a surgeon'"'"'s Gigli saw comprising the steps of:

providing a plurality of individual wires;

passing said plurality of wires as a bundle through a coining stand to form a strand of said wires substantially coined into a polygonal cross-sectional shape;

twisting at least one of said strands in a first rotational direction;

providing a plurality of such strands; and

twisting said plurality of strands in the opposite rotational direction into a cable.

17. The method as set forth in claim 16, wherein said polygonal cross-sectional shape is rectangular.

18. The method as set forth in claim 16, wherein said twisting step includes twisting all of said strands in said first rotational direction.

19. The method as set forth in claim 16, wherein each of said polygonal cross-sectional shapes is substantially square.

20. The method as set forth in claim 16, including providing a sharp edge of not more than about a 90-degree included angle on said polygonal cross-sectional shape.

21. The method as set forth in claim 16, including twisting said bundle of wires prior to passing through said coining stand.

22. The method as set forth in claim 16, wherein the strand twisting step includes twisting together three of said strands.

23. The method as set forth in claim 16, wherein the passing step includes passing said plurality of wires through a Turk'"'"'s-head roller stand.

24. The method as set forth in claim 23, wherein the passing step includes offsetting the rolls in the Turk'"'"'s-head roller stand to form projecting ears at the edges of intersecting faces on the sides of the strand.

25. The method as set forth in claim 16, wherein said passing step includes passing three wires through the coining stand.

26. The method as set forth in claim 16, including stress relieving said strands prior to twisting into said cable.

27. The method as set forth in claim 16, wherein said strand twisting step includes twisting the strands into a cable with approximately one-half the number of twists per inch of said at least one of the strands.