Patent US3600810A successfully refreshed from Google Patents.
US3600810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental instruments
Assignee: Premach Pty Ltd
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Filing: 1969-09-30
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Granted: 1971-08-24
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Expires: 1989-09-30
Abstract
Abstract An aid for the dental preparation of a tooth for a jacket crown in which the depth of an axial cut and a circumferential cut of a bur is controlled mechanically, the aid comprising firstly a guide member securable over the bur and having a stem partly enclosing the bur and an outer tip to engage and protect a patient''s gum and contacting the base of a tooth to limit the depth of circumferential cut, and secondly a barrel slidably housing a drive motor carrying the bur, the barrel being inserted into a guide sleeve fixable in the patient''s mouth and having a follower engageable with a cam on the sleeve to limit the axial insertion of the barrel and bur so that the axial limit of the cut of the bur follows the patient''s gum line.
Inventors
- 👤 Kenneth Henry Marshall
- 👤 Bruce Bertram Burns
- 👤 Thomas Laidlaw Gregan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:41
CPC Classifications
A; A61; A61C; A61C3/00; A61C3/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
An improved dental instrument for use in preparing the tooth of a patient for the installation of a jacket crown, said instrument to be used in conjunction with a bur and a hollow guide sleeve having a pair of opposed ends and means for detachably fixing said sleeve within the mouth of the patient, the improvement comprising: a cylindrical barrel which is freely rotatable and controllably axially slidable within said guide sleeve to permit controlled subgingival cutting of said tooth, a turbine assembly mounted in said barrel, said turbine assembly being mounted for transverse sliding movement said bur being connected to said turbine assembly for rotation thereby and said bur extending from said barrel for engagement with the tooth, resilient means for biasing said turbine assembly and said bur into cutting contact radially of said tooth, and a removable guide member shading the bur, said guide member having means for engaging said tooth for resisting the force of said resilient means on said turbine assembly and said bur to thereby control the radial depth of cutting by said bur.
Claim 2
Dependent Claim
179 words
An improved dental instrument for use in preparing the tooth of a patient for the installation of a jacket crown, said instrument to be used in conjunction with a bur and a hollow guide sleeve having a pair of opposed ends and means for detachably fixing said sleeve within the mouth of the patient, the improvement comprising: a cylindrical barrel which is freely rotatable and controllably axially slidable within said guide sleeve to permit controlled subgingival cutting of said tooth, a turbine assembly mounted in said barrel, said turbine assembly being mounted for transverse sliding movement said bur being connected to said turbine assembly for rotation thereby and said bur extending from said barrel for engagement with the tooth, resilient means for biasing said turbine assembly and said bur into cutting contact radially of said tooth, and a removable guide member shading the bur, said guide member having means for engaging said tooth for resisting the force of said resilient means on said turbine assembly and said bur to thereby control the radial depth of cutting by said bur.
Claim 3
Dependent Claim
63 words
A dental instrument as set forth in claim 1 including: a cam follower mounted on said barrel, and one end of said sleeve is contoured to form a cam track, said cam follower engaging said cam track to limit the degree of axial penetration of said bur beneath the gingival margin of said tooth as said barrel is rotated within said guide sleeve.
Claim 4
Dependent Claim
48 words
A device as set forth in claim 1 wherein said barrel has an end wall with a diametral opening therethrough through which said bur extends, and said turbine assembly is mounted in a plug, said bur being slidable along said diametral opening on transverse movement of said plug.
Claim 5
Dependent Claim
43 words
A device as set forth in claim 3 including a rack mounted on said plug, and operating means mounted on said barrel for engaging said rack to move said plug, said turbine assembly and said bur against the force of said resilient means.
Claim 6
Dependent Claim
73 words
A device as set forth in claim 4 including locking means disposed in said housing for locking said plug in position in said barrel to facilitate removal and return of said barrel with respect to said guide sleeve without alteration of the relative radial position of said bur with respect to said tooth where it is necessary to remove said guide sleeve to permit unobstructed cutting of the proximal faces of said tooth.
Claim 7
Dependent Claim
64 words
A dental instrument as set forth in claim 3 including: a cam follower mounted on said barrel, and one end of said guide sleeve is contoured to form a cam track, said cam follower engaging said cam track to limit the degree of axial penetration of said bur beneath the gingival margin of said tooth as said barrel is rotated within said guide sleeve.
Claim 8
Dependent Claim
64 words
A dental instrument as set forth in claim 4 including: a cam follower mounted on said barrel, and one end of said guide sleeve is contoured to form a cam track, said cam follower engaging said cam track to limit the degree of axial penetration of said bur beneath the gingival margin of said tooth as said barrel is rotated within said guide sleeve.
Claim 9
Dependent Claim
65 words
A dental instrument as set forth in claim 5 including: a cam follower mounted on said barrel, and one end of said guide sleeve is contoured to form a cam track, said cam follower engaging said caM track to limit the degree of axial penetration of said bur beneath the gingival margin of s said tooth as said barrel is rotated within said guide sleeve.
Claim 10
Dependent Claim
34 words
A device as set forth in claim 1 including an extended finger knob mounted on said barrel whereby the barrel may be manually rotated within said guide sleeve as cutting of the tooth progresses.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |