Patent US3656201A successfully refreshed from Google Patents.
US3656201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination blackboard chalk and eraser
Assignee: Individual
•
Filing: 1969-12-12
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Granted: 1972-04-18
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Expires: 1989-12-12
Abstract
Abstract A combined blackboard chalk and eraser in which the chalk is provided with an embedded eye to permit the chalk to be attached to a cord and suspended from the top of the blackboard. The chalk has an eraser element secured to one end thereof so that the board can be erased, using the chalk as a handle for the eraser.
Inventors
- 👤 Francisco O Alcocer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:01
CPC Classifications
B; B43; B43L; B43L21/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A combined blackboard chalk and eraser comprising a porous plastic foam eraser body having opposed upper and lower faces and an elongate chalk body cast in contiguous relation with the lower face of said eraser body, with the grains of said chalk body passing through the lower face of said eraser body to bond said eraser body and chalk body together as a single unit.
Claim 2
Dependent Claim
65 words
A combined blackboard chalk and eraser comprising a porous plastic foam eraser body having opposed upper and lower faces and an elongate chalk body cast in contiguous relation with the lower face of said eraser body, with the grains of said chalk body passing through the lower face of said eraser body to bond said eraser body and chalk body together as a single unit.
References Cited (Backward Citations)
US1103955A
Cited
FR616440A
Cited
US1750912A
Cited
FR702323A
Cited
US2086174A
Cited
US2188544A
Cited
FR1003088A
Cited
US3257679A
Cited
US3418673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |