US4108557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Error correcting typewriter
Assignee: TA Triumph-Adler GmbH
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Filing: 1977-02-10
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Granted: 1978-08-22
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Expires: 1997-02-10
Abstract
Abstract An error correction system for a typewriter in which a silent type action with a blank type face is operatively connected and synchronized to initiate a backspace action and elevate and feed an error correction ribbon in advance of the striking of the blank type face against the space wherein an error was printed. Thus, to obliterate an error and type in a correct character, an operator need only perform two operations; depress the error key and the correct character key. Further, in accordance with the invention, the error key may be further depressed to a repeat position whereby a series of characters may be obliterated automatically.
Inventors
- 👤 Jurgen Skrzipek
- 👤 Helge Reuter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:30
CPC Classifications
B; B41; B41J; B41J29/00; B41J29/26; B41J29/36; B41J29/32; B41J29/34; B41J5/00; B41J5/08; B41J5/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
143 words
An error correcting typewriter having an error correction ribbon, means for elevating said error correction ribbon opposite the printing point of a typewriter, means for feeding said error correction ribbon to present a fresh area for elevation opposite said printing point, a carriage, means for initiating a backspace action for backspacing said carriage, a silent type action having a blank type face, an error correction keylever depressible to a first limit position for initiating operation of said silent type action, and means responsive to depression of said error correction keylever to said first limit position for operating, in advance of the printing of said blank type face, in sequence, said backspace action, said error correction ribbon elevating means, and said error correction ribbon feeding means, whereby a previously typed character can be erased and a correct character typed in the same character space.
Claim 2
Dependent Claim
143 words
An error correcting typewriter having an error correction ribbon, means for elevating said error correction ribbon opposite the printing point of a typewriter, means for feeding said error correction ribbon to present a fresh area for elevation opposite said printing point, a carriage, means for initiating a backspace action for backspacing said carriage, a silent type action having a blank type face, an error correction keylever depressible to a first limit position for initiating operation of said silent type action, and means responsive to depression of said error correction keylever to said first limit position for operating, in advance of the printing of said blank type face, in sequence, said backspace action, said error correction ribbon elevating means, and said error correction ribbon feeding means, whereby a previously typed character can be erased and a correct character typed in the same character space.
Claim 3
Dependent Claim
41 words
An error correcting typewriter as recited in claim 1, wherein said means responsive to depression of said error correction keylever for operating said error correction ribbon feeding means, comprises means in the path of and operative by said silent type action.
Claim 4
Dependent Claim
63 words
An error correcting typewriter as recited in claim 1, wherein said error correction keylever is depressible to a second limit position and wherein said means responsive to error correction keylever depression includes means for repeatedly initiating said silent type action and for repeatedly initiating said backspace action for as long as said error correction keylever is held depressed to the second limit position.
Claim 5
Dependent Claim
75 words
An error correcting typewriter as recited in claim 1, wherein said error correction keylever is depressible to a second limit position, said means for initiating a backspace action including a backspace keylever movable to first and second limit positions incident to movement of said error correction keylever to first and second limit positions, and means responsive to backspace keylever depression to said first and second limit positions for initiating respectively single and repeat backspace actions.
Claim 6
Dependent Claim
159 words
An error correcting typewriter as recited in claim 3, said means for initiating repeat silent type actions in response to depression of said error correction keylever to a second limit position including a release lever pivotally and slidably mounted intermediate its ends on said error correction keylever, an abutment in the path of one end of said release lever for rocking said release lever incident to depression of said error correction keylever to a first limit position thereby to initiate a silent type action, said silent type action translating said release lever, said abutment holding said translated release lever in a non-repeat position until release of said error correction keylever, said abutment being located to further rock said release lever incident to depression of said error correction keylever to a second limit position whereby repeat silent type actions and repeat backspacing will ensue for as long as said error correction keylever is held depressed to said second limit position.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-21 | 1982-02-20 | 1982-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-21 | 1986-02-20 | 1986-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-21 | 1990-02-20 | 1990-08-22 | $7700.00 | Window Closed / Lapsed |