US4257712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
End of paper indicator for typewriters
Assignee: Individual
•
Filing: 1977-06-17
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Granted: 1981-03-24
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Expires: 1997-06-17
Abstract
Abstract A length of light piping is formed to fit in a position in a typewriter with a pickup end viewing the contrast between the black paper roller and a light end of a paper sheet as it nears an exit position from the roller, and with a viewing end visible to the typist for sensing the end of the paper visually.
Inventors
- 👤 Francis G. McGuire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:18
CPC Classifications
B; B41; B41J; B41J29/00; B41J29/46; B41J29/48
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
A typewriter mechanism, comprising in combination, a dark paper roller, a housing, and a wireless end of paper indicator operable in a mode sensing surface contrast between a paper roller and paper consisting of a length of light piping disposed between (a) a first position at one pickup end viewing the surface of the paper roller at a position where a paper sheet carried thereby is interposed between the pickup end and the roller until it nears an exit position from the roller thereby to indicate by contrast in color that the paper edge is nearing the end of a typed page, and (b) a second position at the other viewing end disposed in said housing for visibility by a typist when typing on said typewriter, whereby the contrast between the dark paper roller and a light paper sheet indicates by light carried to the viewing end of the light pipe the presence or absence of a sheet of paper between the roller and the pickup end.
Claim 2
Dependent Claim
167 words
A typewriter mechanism, comprising in combination, a dark paper roller, a housing, and a wireless end of paper indicator operable in a mode sensing surface contrast between a paper roller and paper consisting of a length of light piping disposed between (a) a first position at one pickup end viewing the surface of the paper roller at a position where a paper sheet carried thereby is interposed between the pickup end and the roller until it nears an exit position from the roller thereby to indicate by contrast in color that the paper edge is nearing the end of a typed page, and (b) a second position at the other viewing end disposed in said housing for visibility by a typist when typing on said typewriter, whereby the contrast between the dark paper roller and a light paper sheet indicates by light carried to the viewing end of the light pipe the presence or absence of a sheet of paper between the roller and the pickup end.
Claim 3
Dependent Claim
75 words
A mechanism as defined in claim 1 wherein the light piping comprises a spread out portion at the pickup end encompassing a range of positions over a plurality of typed line spacings on the paper and corresponding spread out over a range of positions at the other viewing end to convey said contrast over said range as the end of a sheet of paper passes the pickup end and travels through said plurality of spacings.
Claim 4
Dependent Claim
26 words
A mechanism as defined in claim 2 wherein said light piping comprises a bundle of light fibers spread out at the ends from a bundle therebetween.
Claim 5
Dependent Claim
89 words
A wireless end of paper indicator for a typewriter consisting of a length of light piping formed to take a position in said typewriter between a typist viewing position and a sensing position that the end of a sheet of paper carried by an advancing roller in the typewriter takes near the exit of the sheet from the typewriter to thereby present to the sensing position a color contrast between the roller and the paper which in turn is viewed at the viewing position by transmission through said pipe.
Claim 6
Dependent Claim
89 words
A wireless end of paper indicator for a typewriter consisting of a length of light piping formed to take a position in said typewriter between a typist viewing position and a sensing position that the end of a sheet of paper carried by an advancing roller in the typewriter takes near the exit of the sheet from the typewriter to thereby present to the sensing position a color contrast between the roller and the paper which in turn is viewed at the viewing position by transmission through said pipe.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-23 | 1984-09-22 | 1985-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-23 | 1988-09-22 | 1989-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-23 | 1992-09-22 | 1993-03-24 | $7700.00 | Window Closed / Lapsed |