US4928127A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet circulation in a duplex printer
Assignee: Xerox Corp
•
Filing: 1989-05-30
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Granted: 1990-05-22
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Expires: 2009-05-30
Abstract
Abstract A duplex printer (or copier) 10 has a copy sheet output path 92 through output rollers 84, curved chute 96, and output rollers 67 into output tray 86. Commonly utilizing a substantial portion thereof is a duplexing path 94 for returning copy sheets to be imaged on their opposite sides to make duplex copies. Rollers 67 alternatively, with reversal, feeds copy sheets into the duplex path 94, aided by rollers 84 at the path separation. The distance between output rollers 84 and the reversible ejecting rollers 67 along the chute 96 is substantial, preferably approximately one half the sheet dimension in the sheet feeding direction of the shortest sheet to be duplexed. The rollers 84 feed copy sheets through the copy sheet output path 92 to the reversible rollers 67 until about one half of the sheet extends out of their nip of these rollers 67. A reversed sheet can then be uninterruptedly reverse fed by, outside, of another sheet moving in the opposite direction in the same arcuate chute 96, for a substantial time period. Thus, a subsequent copy sheet may be fed downstream (upwardly) in the output path 92 simultaneously with, for a substantial time period, the reverse (downward) feeding of the preceding copy sheet into the duplex path 94, to enable slow, uncritical, reversals of rollers 67 even if the sheets are closely spaced in the output path. The duplex path 94 has an even greater path distance between the reversible rollers 67 and the first duplex path feed nip 90, which is separate from the rollers 84.
Inventors
- 👤 Denis J. Stemmle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/23; G03G15/231; G03G15/232; G03G15/234
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
371 words
In a duplex printer or copier with a copy sheet output path, and a connecting duplexing path for returning copy sheets to be imaged on their opposite sides to make duplex copies, said duplexing path including a copy sheet inverting system with reversible copy sheet output path rollers to alternatively advance copy sheets, or with reversal, to transport copy sheets into said duplex path, the improvement comprising; output path roller nip means for feeding copy sheets therefrom downstream through said copy sheet output path to said reversible copy sheet output path rollers, copy sheet guide path means extending between, and providing a copy sheet guide path between, said output path roller nip means and said reversible copy sheet output path rollers, said copy sheet guide path comprising a portion of said copy sheet output path and an initial portion of said duplexing path, and having a copy sheet guide path length between said output path roller nip means and said reversible copy sheet output path rollers which is a substantial portion of the dimension of the copy sheet being fed but substantially less than said copy sheet dimension so that a substantial portion of the copy sheet is extendable through and downstream of said reversible copy sheet output path rollers before the copy sheet is released by said output path roller nip means, so that a subsequent copy sheet may be fed downstream in said copy sheet guide path by said output path roller nip means towards said reversible copy sheet output path rollers simultaneously with, for a substantial time period with, the reverse feeding of the preceding copy sheet by said reversible copy sheet output path rollers into said duplex path, and duplexing path transport means in said duplexing path for acquiring and feeding in said duplexing path copy sheets being reversibly driven by said reversible copy sheet output path rollers, said duplexing path transport means being mounted in said duplexing path to have a copy sheet guide path length between said duplexing path transport means and said reversible copy sheet output path rollers which is substantially greater than said copy sheet guide path length between said output path roller nip means and said reversible copy sheet output path rollers.
Claim 2
Dependent Claim
371 words
In a duplex printer or copier with a copy sheet output path, and a connecting duplexing path for returning copy sheets to be imaged on their opposite sides to make duplex copies, said duplexing path including a copy sheet inverting system with reversible copy sheet output path rollers to alternatively advance copy sheets, or with reversal, to transport copy sheets into said duplex path, the improvement comprising; output path roller nip means for feeding copy sheets therefrom downstream through said copy sheet output path to said reversible copy sheet output path rollers, copy sheet guide path means extending between, and providing a copy sheet guide path between, said output path roller nip means and said reversible copy sheet output path rollers, said copy sheet guide path comprising a portion of said copy sheet output path and an initial portion of said duplexing path, and having a copy sheet guide path length between said output path roller nip means and said reversible copy sheet output path rollers which is a substantial portion of the dimension of the copy sheet being fed but substantially less than said copy sheet dimension so that a substantial portion of the copy sheet is extendable through and downstream of said reversible copy sheet output path rollers before the copy sheet is released by said output path roller nip means, so that a subsequent copy sheet may be fed downstream in said copy sheet guide path by said output path roller nip means towards said reversible copy sheet output path rollers simultaneously with, for a substantial time period with, the reverse feeding of the preceding copy sheet by said reversible copy sheet output path rollers into said duplex path, and duplexing path transport means in said duplexing path for acquiring and feeding in said duplexing path copy sheets being reversibly driven by said reversible copy sheet output path rollers, said duplexing path transport means being mounted in said duplexing path to have a copy sheet guide path length between said duplexing path transport means and said reversible copy sheet output path rollers which is substantially greater than said copy sheet guide path length between said output path roller nip means and said reversible copy sheet output path rollers.
Claim 3
Dependent Claim
42 words
The duplex printer or copier of claim 1, wherein said copy sheet guide path length between said output path roller nip means and said reversible copy sheet output path rollers is approximately one half of the feeding dimension of the copy sheet.
Claim 4
Dependent Claim
48 words
The duplex printer or copier of claim 1, wherein said output path transport means and said duplexing path transport means each comprise single nip pairs of sheet feed rollers which are substantially spaced apart, with said duplexing path transport means being separately positioned only in said duplexing path.
Claim 5
Dependent Claim
40 words
The duplex printer or copier of claim 1, wherein said output path roller nip means is positioned and driven to also function to direct copy sheets reversibly driven by said reversible copy sheet output path rollers into said duplexing path.
Claim 6
Dependent Claim
45 words
The duplex printer or copier of claim 1, wherein said output path roller nip means is in said copy sheet guide path and defining a part of said copy sheet output path but partially extends into said duplexing path to assist in deflecting sheets therein.
Claim 7
Dependent Claim
125 words
The duplex printer or copier of claim 1, wherein said copy sheet guide path between said output path roller nip means and said reversible copy sheet output path rollers is arcuate and approximately one half of the feeding dimension of the copy sheet in path length; wherein said output path roller nip means and said duplexing path transport means each comprise single nip pairs of sheet feed rollers which are substantially spaced apart, with said duplexing path transport means being separately positioned only in said duplexing path; and wherein said output path roller nip means is in said copy sheet guide path and defining a part of said copy sheet output path but partially extends into said duplexing path to assist in deflecting sheets therein.
Claim 8
Dependent Claim
39 words
The duplex printer or copier of claim 1 wherein said reversible copy sheet output path rollers are not reversed for fully duplexed copy sheets copied on both sides and ejects said duplexed copy sheets directly into an output tray.
Claim 9
Dependent Claim
36 words
The duplex printer or copier of claim 1 wherein said reversible copy sheet output path rollers are driven at a different reverse than fowrd sheet feeding velocity to provide a different duplexing path sheet feeding velocity.
References Cited (Backward Citations)
DE1365835U
Cited
US4110025A
Cited
US4272181A
Cited
US4234180A
Cited
US4334765A
Cited
US4348101A
Cited
US4346880A
Cited
JPS58118666A
Cited
US4487506A
Cited
US4466733A
Cited
US4488801A
Cited
US4553831A
Cited
US4745490A
Cited
US4630921A
Cited
US4699503A
Cited
US4787616A
Cited
US4692020A
Cited
US4769675A
Cited
US4745439A
Cited
US4743945A
Cited
US4847654A
Cited
US4708462A
Cited
US4853740A
Cited
US4772915A
Cited
US4752801A
Cited
US4806979A
Cited
US4780745A
Cited
US4758862A
Cited
US4825245A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |