US5019078A
Expired / Lapsed
US
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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
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 15:17
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)
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 |