US3103751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chalkless writing board
Assignee: Individual
•
Filing: 1961-05-05
•
Granted: 1963-09-17
•
Expires: 1981-05-05
Abstract
No abstract record available.
Inventors
- 👤 Wilfred J Mcdonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:35
CPC Classifications
B; B43; B43L; B43L1/00; B43L1/008; B43L5/00; B43L5/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
57 words
A WRITING BOARD FOR USE WITH A MAGNETIC STYLUS COMPRISING IN COMBINATION A FRONT RIGID TRANSPARENT NONMAGNETIC PLATE, A BACK NON-MAGNETIC PLATE HAVING A PLURALITY OF APERTURES THEREIN, SPACED FROM SAID FRONT PLATE AND SECURED THERETO TO PROVIDE A CHAMBER THEREBETWEEN AND A PLURALITY OF METALLIC PINS SLIDABLY MOUNTED IN THE APERTURES AND CONFINED WITHIN SAID CHAMBER.
Claim 2
Dependent Claim
57 words
A WRITING BOARD FOR USE WITH A MAGNETIC STYLUS COMPRISING IN COMBINATION A FRONT RIGID TRANSPARENT NONMAGNETIC PLATE, A BACK NON-MAGNETIC PLATE HAVING A PLURALITY OF APERTURES THEREIN, SPACED FROM SAID FRONT PLATE AND SECURED THERETO TO PROVIDE A CHAMBER THEREBETWEEN AND A PLURALITY OF METALLIC PINS SLIDABLY MOUNTED IN THE APERTURES AND CONFINED WITHIN SAID CHAMBER.
References Cited (Backward Citations)
US2589601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-09-16 | 1967-03-18 | 1967-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-09-16 | 1971-03-18 | 1971-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-09-16 | 1975-03-18 | 1975-09-17 | $7700.00 | Window Closed / Lapsed |