Patent US3755924A successfully refreshed from Google Patents.
US3755924A
Expired / Lapsed
US
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Arithmetic teaching device
Assignee: Hasbro Inc
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Filing: 1972-08-03
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Granted: 1973-09-04
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Expires: 1992-08-03
Abstract
Abstract An arithmetical teaching device having an elongated housing with a plurality of aligned slidable buttons secured therein. The buttons have transparent faces. Indicia is printed on the interior base of each of the buttons. One space equivalent to the size of one button is provided so that the movement of the buttons may be accomplished. The lowest number indicia is printed on the interior base of the housing at one end thereof. Each of the buttons except one includes opaque means extending from within the buton for covering and uncovring the indicia of an adjacent button as they are moved in one direction and the other within the housing.
Inventors
- 👤 M Langieri
- 👤 M Meyers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:27
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
116 words
An arithmetical teaching device comprising a housing, a plurality of transparent buttons slidably secured within said housing substantially in alignment therein, said buttons including a base, indicia imprinted on the interior of said base of each of said buttons and visible through the upper section thereof, and opaque means extending from within selected ones of said buttons for covering and uncovering the indicia of the adjacent button, said opaque means comprising a coplanar extension of said base extending over a portion of the base of the adjacent button, said housing including one space substantially the same size as one of said buttons, said space being imprinted with the lowest digit relative to said consecutively numbered buttons.
Claim 2
Dependent Claim
116 words
An arithmetical teaching device comprising a housing, a plurality of transparent buttons slidably secured within said housing substantially in alignment therein, said buttons including a base, indicia imprinted on the interior of said base of each of said buttons and visible through the upper section thereof, and opaque means extending from within selected ones of said buttons for covering and uncovering the indicia of the adjacent button, said opaque means comprising a coplanar extension of said base extending over a portion of the base of the adjacent button, said housing including one space substantially the same size as one of said buttons, said space being imprinted with the lowest digit relative to said consecutively numbered buttons.
Claim 3
Dependent Claim
20 words
The device of claim 1 further comprising guide means integral with said housing for maintaining said slidable buttons in alignment.
Claim 4
Dependent Claim
20 words
The device of claim 1 further comprising means in the upper face of said button for facilitating manual movement therof.
Claim 5
Dependent Claim
24 words
The device of claim 3 wherein said means in the upper face of said button comprises a re-entrant section adapted to accommodate a digit.
References Cited (Backward Citations)
AT179113B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |