Patent US3672414A successfully refreshed from Google Patents.
US3672414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead sharpener
Assignee: Individual
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Filing: 1969-12-05
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Granted: 1972-06-27
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Expires: 1989-12-05
Abstract
Abstract A lead sharpener which may be carried in the pocket of a coat and comprises a head with an inclined lead-holder channel which is partly inserted in and rotatable relative to a housing and about a fixed milling cutter in the housing so that the tip of the lead to be sharpened revolves about the cutter. The main weight of this head is located within the housing so as to attain a flywheel effect as closely as possible to the milling cutter when the head is turned to sharpen the tip of a lead.
Inventors
- 👤 Gerald W Dahle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:53
CPC Classifications
B; B43; B43L; B43L23/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
177 words
A blead sharpener comprising a housing having an upper open end, a shaft nonrotatably mounted in said housing, a cylindrical steel milling cutter rigidly secured to said shaft, a head member consisting of a heavy metal and forming a fly-wheel, said head member having a heavy substantially cylindrical part mounted in the upper end of said housing and rotatably mounted on said shaft, an annular flange on said head member above said cylindrical part and adapted to slide along the upper end surface of said housing and to substantially seal said housing, said cylindrical part having an annular groove in its peripheral surface at a distance from said flange, the inner wall surface of said housing also having an annular groove located in a position corresponding to that of said groove in the cylindrical part, and a spring ring located in both grooves for rotatably connecting said head to said housing, said head member having a lead-holder guide channel inclined to the axis of said shaft and extending into said housing to a point near said cutter.
Claim 2
Dependent Claim
177 words
A blead sharpener comprising a housing having an upper open end, a shaft nonrotatably mounted in said housing, a cylindrical steel milling cutter rigidly secured to said shaft, a head member consisting of a heavy metal and forming a fly-wheel, said head member having a heavy substantially cylindrical part mounted in the upper end of said housing and rotatably mounted on said shaft, an annular flange on said head member above said cylindrical part and adapted to slide along the upper end surface of said housing and to substantially seal said housing, said cylindrical part having an annular groove in its peripheral surface at a distance from said flange, the inner wall surface of said housing also having an annular groove located in a position corresponding to that of said groove in the cylindrical part, and a spring ring located in both grooves for rotatably connecting said head to said housing, said head member having a lead-holder guide channel inclined to the axis of said shaft and extending into said housing to a point near said cutter.
Claim 3
Dependent Claim
90 words
A lead sharpener as defined in claim 1, in which said spring ring loosely engages into said groove in said cylindrical part and presses tightly against the wall of said groove in said housing so as to be stationary relative thereto when said head is rotated, said ring serving in addition to said flange as a sealing member to prevent the powder ground off said leads from falling out of said housing when said sharpener is held in a position in which the bottom of said housing is not horizontal.
Claim 4
Dependent Claim
60 words
A lead sharpener as defined in claim 1, further comprising a separate plug member adapted to be inserted into said guide channel when said sharpener is not in use, said plug member having a length substantially equal to the length of said channel and such a shape that, when inserted in said channel, it closes off its inner end completely.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |