US4699550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cranial perforator
Assignee: Individual
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Filing: 1986-04-01
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Granted: 1987-10-13
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Expires: 2006-04-01
Abstract
Abstract A new drill-type cranial perforator is disclosed of the type which comprises a front drill head assembly made up of a leading inner drill and a trailing outer drill, and a rear support and drive assembly adapted to enable both drills so long as the leading inner drill is encountering a resistive surface and to disable both drills when the leading inner drill stops encountering the resistive surface.
Inventors
- 👤 John W. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:56
CPC Classifications
B; B23; B23B; B23B51/00; A; A61; A61B; A61B17/00; A61B17/16; A61B17/1695; B23B51/009; A61B90/00; A61B90/08; A61B2090/0814; B23B2251/00; B23B2251/14; Y; Y10; Y10T; Y10T408/00; Y10T408/70; Y10T408/89; Y10T408/905; Y10T408/906
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
An improved drilling implement for drilling holes in bone structures comprising: a drill head assembly including inner and outer drill members each having a plurality of shaped drilling flutes with cutting edges, a drill head drive assembly, and clutch means for selectively coupling and de-coupling said drill head assembly and said drill head drive assembly according to the resistance to bone penetration encountered by said drill head assembly; characterized in that each flute of said inner drill member is identical to every other flute of said inner drill member and comprises a plurality of prismatic surfaces and a front cutting edge, a pyramidal center point is provided which projects forwardly of said front cutting edges, and each flute has a notch separating its said front cutting edge from said pyramidal center point.
Claim 2
Dependent Claim
132 words
An improved drilling implement for drilling holes in bone structures comprising: a drill head assembly including inner and outer drill members each having a plurality of shaped drilling flutes with cutting edges, a drill head drive assembly, and clutch means for selectively coupling and de-coupling said drill head assembly and said drill head drive assembly according to the resistance to bone penetration encountered by said drill head assembly; characterized in that each flute of said inner drill member is identical to every other flute of said inner drill member and comprises a plurality of prismatic surfaces and a front cutting edge, a pyramidal center point is provided which projects forwardly of said front cutting edges, and each flute has a notch separating its said front cutting edge from said pyramidal center point.
Claim 3
Dependent Claim
40 words
An improved drilling implement according to claim 1 wherein each flute of said inner drill member has a longitudinally-extending cutting edge formed by the intersection of one of said prismatic surfaces and the outer surface of said inner drill member.
Claim 4
Dependent Claim
40 words
An improved drilling implement according to claim 1 wherein each flute of said inner drill member is formed by at least one prismatic surface which is disposed so that it is eccetric to center axis of said inner drill member.
Claim 5
Dependent Claim
79 words
An improved drilling implement according to claim 1 wherein said inner drill member has a plurality of flutes each having a front end surface terminating in a front cutting edge, and said outer drill member has a plurality of flutes each having a front end surface terminating in a front cutting edge, and further wherein the front end surfaces of said inner and outer drill members are disposed at different angles to the longitudinal axis of said drilling implement.
Claim 6
Dependent Claim
19 words
An improved drilling implement according to claim 1 wherein said inner and outer drill members each have three flutes.
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) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |