US4203223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Periodontal probe
Assignee: Northwestern University
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Filing: 1979-01-12
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Granted: 1980-05-20
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Expires: 1999-01-12
Abstract
Abstract A force-controlled periodontal probe is disclosed, the probe having a scale-marked shaft slidably carried by an alignment sleeve at the head end of the instrument and urged into a normally extended condition by a thin leaf spring. Measurements of gingival sulcus depths are taken when the force applied by the periodontist to the handle of the instrument and the resistance to further penetration by the tip portion of the shaft have caused the shaft to shift into an indicated displaced position. In that position the spring exerts a predetermined and accurately reproducible probing force.
Inventors
- 👤 Eugene P. Lautenschlager
- 👤 Peter J. Robinson
- 👤 Randall M. Vitek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:53
CPC Classifications
A; A61; A61C; A61C3/00; A61C19/00; A61C19/04; A61C19/043
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
147 words
A periodontal probe comprising an elongated handle having a head end provided with a generally transversely-extending sleeve; a probe shaft slidably supported by said sleeve, said shaft including an elongated tip at one end thereof and bearing means at the opposite end thereof; a leaf spring having one end secured to said handle and an opposite end engaging said bearing means for urging said shaft in one direction to extend said tip away from said sleeve, the force exerted by said spring upon said shaft progressively increasing as said shaft is displaced in a direction opposite from said one direction; stop means for limiting the extent of movement of said shaft in said one direction; and means provided by said shaft and sleeve for indicating when said shaft is retracted to a point at which said spring exerts an extending force of predetermined magnitude upon said shaft.
Claim 2
Dependent Claim
147 words
A periodontal probe comprising an elongated handle having a head end provided with a generally transversely-extending sleeve; a probe shaft slidably supported by said sleeve, said shaft including an elongated tip at one end thereof and bearing means at the opposite end thereof; a leaf spring having one end secured to said handle and an opposite end engaging said bearing means for urging said shaft in one direction to extend said tip away from said sleeve, the force exerted by said spring upon said shaft progressively increasing as said shaft is displaced in a direction opposite from said one direction; stop means for limiting the extent of movement of said shaft in said one direction; and means provided by said shaft and sleeve for indicating when said shaft is retracted to a point at which said spring exerts an extending force of predetermined magnitude upon said shaft.
Claim 3
Dependent Claim
35 words
The probe of claim 1 in which said probe tip is provided with spaced scale markings for indicating the depth of insertion of said tip in a gingival sulcus at said force of predetermined magnitude.
Claim 4
Dependent Claim
22 words
The probe of claim 1 in which means are provided for adjusting the force exerted by said spring upon said bearing means.
Claim 5
Dependent Claim
74 words
The probe of claim 3 in which said means for adjusting said force includes a collar threadedly mounted upon said handle near said head end thereof, said one end of said leaf spring extending through said collar, whereby, screwing said collar one way or the other along said handle varied the length of the spring between said collar and bearing means and thereby alters the force exerted by said spring upon said bearing means.
Claim 6
Dependent Claim
31 words
The probe of claim 1 in which said bearing means comprises an enlargement of said shaft adjacent said opposite end thereof, said enlargement providing a rounded bearing surface engaging said spring.
Claim 7
Dependent Claim
40 words
The probe of claim 5 in which said enlargement has a diameter greater than the inside diameter of said sleeve and also serves as said stop means for limiting the extent of movement of said shaft in said one direction.
Claim 8
Dependent Claim
23 words
The probe of claim 6 in which said enlargement comprises a generally spherical element secured to said shaft adjacent said opposite end thereof.
Claim 9
Dependent Claim
39 words
The probe of claim 6 in which said spring is provided with a slot adjacent said opposite end thereof, said shaft being provided with a pin extending through said slot for operatively connecting said probe shaft and spring together.
Claim 10
Dependent Claim
56 words
The probe of claim 1 in which said means provided by said shaft and sleeve for indicating when said shaft is displaced to a point at which said spring exerts said force of predetermined magnitude comprises an indicia mark on said shaft alignable with an end portion of said sleeve when said shaft is so displaced.
Claim 11
Dependent Claim
54 words
The probe of claims 1, 3, 5, or 9 in which said leaf spring has a substantial portion of its length extending in normally spaced relation along a side of said handle opposite from said probe shaft tip, whereby, finger pressure may be applied to said spring to increase the resistance against shaft displacement.
Claim 12
Dependent Claim
61 words
The probe of claims 1, 3, or 9 in which the extent of movement of said shaft between the point at which said stop means limits the movement of said shaft in said one direction and the point at which said means indicates that a force of predetermined magnitude is exerted falls within the range of about 1/2 to 2 centimeters.
Claim 13
Dependent Claim
55 words
The probe of claims 1, 3, or 9 in which the extent of movement of said shaft between the point at which said stop means limits the movement of said shaft in said one direction and the point at which said means indicates that a force of predetermined magnitude is exerted is about 1 centimeter.
Claim 14
Dependent Claim
25 words
The probe of claim 1 in which said shaft is provided with a hook adjacent said opposite end thereof for suspending a calibrating weight therefrom.
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) | 1983-05-20 | 1983-11-19 | 1984-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-20 | 1987-11-19 | 1988-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-20 | 1991-11-19 | 1992-05-20 | $7700.00 | Window Closed / Lapsed |