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US5019078A Expired / Lapsed US ⏱️ 0.0 years remaining

Bone screw

Assignee: Queen's University
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Filing: 1989-11-17
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Granted: 1991-05-28
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Expires: 2009-11-17
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Abstract

Abstract A bone screw has a smooth shaft segment, a threaded segment and a tapered transition segment between the shaft and the threaded segment.

Inventors

  • 👤 Stephen M. Perren
  • 👤 Robert Frigg
  • 👤 Paul Gisin
  • 👤 Robert Mathys, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 18:13
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/8625

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 66 words
A bone screw having a head, a smooth shaft segment having a diameter D 1 adjacent said head, a threaded segment and a transition segment between the smooth shaft segment and the threaded segment, said transition segment tapering from a diameter D 1 adjacent said smooth shaft segment to a lesser diameter D 2 adjacent said threaded segment, the ratio ##EQU3## being between 0.001 and 0.040.
Claim 2
Dependent Claim 66 words
A bone screw having a head, a smooth shaft segment having a diameter D 1 adjacent said head, a threaded segment and a transition segment between the smooth shaft segment and the threaded segment, said transition segment tapering from a diameter D 1 adjacent said smooth shaft segment to a lesser diameter D 2 adjacent said threaded segment, the ratio ##EQU3## being between 0.001 and 0.040.
Claim 3
Dependent Claim 15 words
The bone screw claimed in claim 1, wherein the ratio is between 0.010 and 0.030.
Claim 4
Dependent Claim 15 words
The bone screw claimed in claim 1, wherein the transition segment has a self-cutting thread.
Claim 5
Dependent Claim 20 words
The bone screw claimed in claim 1, wherein the transition segment narrows continuously from D 1 to D 2 .
Claim 6
Dependent Claim 15 words
The bone screw claimed in claim 1, wherein the transition segment has a shallow thread.
Claim 7
Dependent Claim 20 words
The bone screw claimed in claim 1 and comprising a milling segment between the threaded segment and the transition segment.
Claim 8
Dependent Claim 36 words
The bone screw claimed in claim 1, wherein the threaded segment has a minor diameter d 1 and a major diameter d 2 , the ratio d 1 /d 2 being between about 0.80 and 0.89.
Claim 9
Dependent Claim 16 words
The bone screw claimed in claim 7, wherein the ratio is between about 0.83 and 0.86.
Claim 10
Dependent Claim 25 words
The bone screw claimed in claim 1, wherein the threaded segment has an automatically expanding screw tip at its end remote from the transition segment.
Claim 11
Dependent Claim 14 words
The bone screw claimed in claim 9, wherein the tip is a Trocar tip.
Claim 12
Dependent Claim 27 words
The bone screw claimed in claim 1, wherein the transition segment is from about 11 to about 15 mm from the remote end of the threaded segment.
Claim 13
Dependent Claim 27 words
The bone screw claimed in claim 11, wherein the transition segment is from about 12 to about 14 mm from the remote end of the threaded segment.
Claim 14
Dependent Claim 18 words
The bone screw claimed in claim 1, wherein the tip of the threaded segment has a corkscrew shape.

References Cited (Backward Citations)

US4463753A Cited
US4524765A Cited
US4468200A Cited
US4913134A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-05-27 1994-11-26 1995-05-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-05-27 1998-11-26 1999-05-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-05-27 2002-11-26 2003-05-28 $7700.00 Window Closed / Lapsed

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