Patent US3924334A successfully refreshed from Google Patents.
US3924334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Root canal implement
Assignee: Kerr Corp
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Filing: 1974-06-21
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Granted: 1975-12-09
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Expires: 1994-06-21
Abstract
Abstract A root canal implement for accepting and holding root canal files and reamers of various sizes includes a threaded knob on one end of the file or reamer wire. The threaded knob is received in the threaded bore of a split chuck handle, wherein threading the knob into the bore determines the length of the exposed file or reamer wire. A locking ring positioned over the split chuck handle constricts the chuck about the knob to prevent the knob and therefore, the wire from turning during clinical use.
Inventors
- 👤 Frank Nickolis Lentine
- 👤 William Francis Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:15
CPC Classifications
A; A61; A61C; A61C5/00; A61C5/40; A61C5/44; Y; Y10; Y10T; Y10T279/00; Y10T279/17; Y10T279/17291; Y10T279/17307
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
206 words
A root canal instrument comprising: a. a wire to be used in filing the root canal of a tooth; b. an externally threaded knob on one end of said wire; c. a generally cylindrical handle having a threaded bore extending therethrough for receiving said threaded knob with said wire projecting outward from a forward end surface of said handle; d. said handle having a forward portion, a rear portion and an intermediate portion tapering outwardly from said rear portion to said forward portion, the smaller diameter of said tapered intermediate portion being less than the diameter of said rear portion, and said handle having a longitudinal slot extending from a rearward end surface thereof through said rear portion and into said tapered intermediate portion, said slot allowing said handle to function as a split chuck; and e. a lock ring positionable on said handle and about said intermediate portion, the inner diameter of said ring being smaller than the diameter of either said forward or rear portions so that said ring will interfere with said tapered surface upon axial movement forward for constricting and locking the rear and intermediate portions of said handle about said knob and will abut said rear portion when moved axially rearward.
Claim 2
Dependent Claim
206 words
A root canal instrument comprising: a. a wire to be used in filing the root canal of a tooth; b. an externally threaded knob on one end of said wire; c. a generally cylindrical handle having a threaded bore extending therethrough for receiving said threaded knob with said wire projecting outward from a forward end surface of said handle; d. said handle having a forward portion, a rear portion and an intermediate portion tapering outwardly from said rear portion to said forward portion, the smaller diameter of said tapered intermediate portion being less than the diameter of said rear portion, and said handle having a longitudinal slot extending from a rearward end surface thereof through said rear portion and into said tapered intermediate portion, said slot allowing said handle to function as a split chuck; and e. a lock ring positionable on said handle and about said intermediate portion, the inner diameter of said ring being smaller than the diameter of either said forward or rear portions so that said ring will interfere with said tapered surface upon axial movement forward for constricting and locking the rear and intermediate portions of said handle about said knob and will abut said rear portion when moved axially rearward.
Claim 3
Dependent Claim
24 words
A dental instrument as set forth in claim 1, wherein said knob is cylindrical and said threads extend for substantially the full length thereof.
Claim 4
Dependent Claim
32 words
A dental instrument as set forth in claim 1, wherein said knob has a transverse slot in the end thereof adapted to receive a tool for threading said knob through said bore.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |