Patent US4243388A successfully refreshed from Google Patents.
US4243388A
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Dental hand engine
Assignee: Dentronics KK
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Filing: 1979-04-20
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Granted: 1981-01-06
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Expires: 1999-04-20
Abstract
Abstract A dental hand engine for driving a reamer for widening root canals, which is characterized in the provision of a control device which electrically senses the time when a forward end of the reamer reaches a radical apex for automatically stopping the engine and consequently the reamer.
Inventors
- 👤 Toshio Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:00
CPC Classifications
A; A61; A61C; A61C19/00; A61C19/04; A61C19/041; A61B; A61B5/00; A61B5/05; A61B5/053; A61B5/0534; A61C1/00; A61C1/0007; A61C5/00; A61C5/40; A61C5/44; A61B17/00; A61B2017/00017; A61B2017/00022; A61B2017/00026; A61B2017/00115; A61B2017/00119; A61B2017/00123; A61C19/042
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
94 words
A dental hand engine for driving a reamer for widening a root canal of tooth, which comprises a body containing the engine and operable by fingers, switch means provided on said body for selectively operating the engine and the reamer connected to said engine, means for passing a micro current through the reamer, and electric circuit means for sensing electric resistances of the micro current passing through the reamer and for stopping the engine and reamer in response to a specific electric resistance said micro current has when the reamer reaches a radical apex.
Claim 2
Dependent Claim
94 words
A dental hand engine for driving a reamer for widening a root canal of tooth, which comprises a body containing the engine and operable by fingers, switch means provided on said body for selectively operating the engine and the reamer connected to said engine, means for passing a micro current through the reamer, and electric circuit means for sensing electric resistances of the micro current passing through the reamer and for stopping the engine and reamer in response to a specific electric resistance said micro current has when the reamer reaches a radical apex.
References Cited (Backward Citations)
US1366877A
Cited
US1713971A
Cited
US3346958A
Cited
US3660901A
Cited
US3839797A
Cited
US3916529A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |