US3140552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for teaching the concept of fractions
Assignee: Individual
•
Filing: 1962-10-29
•
Granted: 1964-07-14
•
Expires: 1982-10-29
Abstract
No abstract record available.
Inventors
- 👤 Robert J Mader
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:57
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
228 words
A DEVICE FOR TEACHING THE CONCEPT OF FRACTIONS COMPRISING A HOLDER UNIT HAVING OPPOSITELY POSITIONED FRONT AND BACK PLATES, SAID FRONT PLATE HAVING A WINDOW AND A PLURALITY OF SLOTS FORMED THEREIN, EACH OF SAID SLOTS RUNNING FROM A POSITION PROXIMATE TO ONE OF THE SIDES OF SAID WINDOW IN A DIRECTION SUBSTANTIALLY NORMAL TO THE ASSOCIATED WINDOW SIDE, SAID BACK PLATE HAVING A PLURALITY OF CHANNELS FORMED THEREIN, EACH OF SAID CHANNELS BEING POSITIONED OPPOSITE AN ASSOCIATED ONE OF SAID SLOTS AND RUNNING IN SUBSTANTIALLY THE SAME DIRECTIONS THEREAS, THE PORTION OF SAID BACK PLATE OPPOSITE SAID WINDOW FORMING A CONTINUATION OF SAID CHANNELS, A SEPARATE SLIDE PLATE SLIDABLY MOUNTED IN EACH OF SAID CHANNELS, EACH OF SAID SLIDE PLATES BEING ADAPTED TO REPRESENT A FRACTIONAL PORTION OF SAID WINDOW, AT LEAST ONE OF SAID SLIDE PLATES BEING MOUNTED FOR MOTION ALONG A FIRST AXIS NORMAL TO ONE OF THE SIDES OF SAID WINDOW, AT LEAST ANOTHER ONE OF SAID SLIDE PLATES BEING MOUNTED FOR MOTION ALONG AN AXIS NORMAL TO SAID FIRST AXIS, SAID ONE OF SAID SLIDE PLATES BEING MARKED INTO SEGMENTS, AND KNOB MEANS ATTACHED TO EACH OF SAID SLIDE PLATES AND PROTRUDING THROUGH AN ASSOCIATED ONE OF SAID SLOTS FOR SELECTIVELY POSITIONING SAID SLIDE PLATES IN SAID WINDOW, WHEREBY VARIOUS COMBINATIONS OF SAID SLIDE PLATES CAN BE MADE TO COMPLETELY FILL SAID WINDOW.
Claim 2
Independent Claim
228 words
A DEVICE FOR TEACHING THE CONCEPT OF FRACTIONS COMPRISING A HOLDER UNIT HAVING OPPOSITELY POSITIONED FRONT AND BACK PLATES, SAID FRONT PLATE HAVING A WINDOW AND A PLURALITY OF SLOTS FORMED THEREIN, EACH OF SAID SLOTS RUNNING FROM A POSITION PROXIMATE TO ONE OF THE SIDES OF SAID WINDOW IN A DIRECTION SUBSTANTIALLY NORMAL TO THE ASSOCIATED WINDOW SIDE, SAID BACK PLATE HAVING A PLURALITY OF CHANNELS FORMED THEREIN, EACH OF SAID CHANNELS BEING POSITIONED OPPOSITE AN ASSOCIATED ONE OF SAID SLOTS AND RUNNING IN SUBSTANTIALLY THE SAME DIRECTIONS THEREAS, THE PORTION OF SAID BACK PLATE OPPOSITE SAID WINDOW FORMING A CONTINUATION OF SAID CHANNELS, A SEPARATE SLIDE PLATE SLIDABLY MOUNTED IN EACH OF SAID CHANNELS, EACH OF SAID SLIDE PLATES BEING ADAPTED TO REPRESENT A FRACTIONAL PORTION OF SAID WINDOW, AT LEAST ONE OF SAID SLIDE PLATES BEING MOUNTED FOR MOTION ALONG A FIRST AXIS NORMAL TO ONE OF THE SIDES OF SAID WINDOW, AT LEAST ANOTHER ONE OF SAID SLIDE PLATES BEING MOUNTED FOR MOTION ALONG AN AXIS NORMAL TO SAID FIRST AXIS, SAID ONE OF SAID SLIDE PLATES BEING MARKED INTO SEGMENTS, AND KNOB MEANS ATTACHED TO EACH OF SAID SLIDE PLATES AND PROTRUDING THROUGH AN ASSOCIATED ONE OF SAID SLOTS FOR SELECTIVELY POSITIONING SAID SLIDE PLATES IN SAID WINDOW, WHEREBY VARIOUS COMBINATIONS OF SAID SLIDE PLATES CAN BE MADE TO COMPLETELY FILL SAID WINDOW.
References Cited (Backward Citations)
US1773670A
Cited
US2914865A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-07-14 | 1968-01-13 | 1968-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-07-14 | 1972-01-13 | 1972-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-07-14 | 1976-01-13 | 1976-07-14 | $7700.00 | Window Closed / Lapsed |