US4570918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Feeder and bottom stacker
Assignee: Xerox Corp
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Filing: 1984-11-19
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Granted: 1986-02-18
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Expires: 2004-11-19
Abstract
Abstract Apparatus for removing the bottom sheets from a stack of sheets or inserting sheets at the bottom of a stack of sheets including an air knife to provide an air cushion between the stack of sheets and the bottom sheet in the stack and a reversible drive roll mounted within a vacuum plenum for driving sheets beneath or away from the sheet stack.
Inventors
- 👤 David Eisler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:46
CPC Classifications
B; B65; B65H; B65H3/00; B65H3/46; B65H3/48; B65H31/00; B65H31/04; B65H31/08; B65H2301/00; B65H2301/40; B65H2301/42; B65H2301/421; B65H2301/4212; B65H2301/42122; B65H2406/00; B65H2406/10; B65H2801/00; B65H2801/03; B65H2801/06; Y; Y10; Y10S; Y10S271/00; Y10S271/902
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
A stacker-feeder for inserting sheet under the bottom of a sheet stack or removing sheets from the bottom of the stack individually, comprising: a paper tray having a curvilinear bottom and a porous backstop; an air knife positioned in front of said tray and adapted to supply air to said curvilinear bottom of said tray such that forces are generated on sheets entering the stack as well as the stack itself in order to lift the stack and lift sheets up to the stack; a vacuum plenum located in a front portion of the bottom of said tray; and, a reversible drive roll positioned within said vacuum plenum and adapted to drive a sheet into and out of the stack once they have been attracted thereto by the vacuum of said vacuum plenum.
Claim 2
Dependent Claim
133 words
A stacker-feeder for inserting sheet under the bottom of a sheet stack or removing sheets from the bottom of the stack individually, comprising: a paper tray having a curvilinear bottom and a porous backstop; an air knife positioned in front of said tray and adapted to supply air to said curvilinear bottom of said tray such that forces are generated on sheets entering the stack as well as the stack itself in order to lift the stack and lift sheets up to the stack; a vacuum plenum located in a front portion of the bottom of said tray; and, a reversible drive roll positioned within said vacuum plenum and adapted to drive a sheet into and out of the stack once they have been attracted thereto by the vacuum of said vacuum plenum.
Claim 3
Dependent Claim
36 words
The stacker-feeder of claim 1, wherein said curvilinear bottom of said tray includes a plurality of ribs extending therefrom which are adapted to present a minimal frictioned surface to sheets coming into or leaving said tray.
Claim 4
Dependent Claim
39 words
The stacker-feeder of claim 1, wherein said tray includes a registration edge and said air knife includes a plurality of thin rectangular nozzles with a majority of said nozzles being directed toward the non-registration edge side of said tray.
Claim 5
Dependent Claim
51 words
The stacker-feeder of claim 3, wherein said nozzles include a plurality of vanes which direct air from said air knife away from the center of the sheet stack and toward the rear corners of the stack in order to enhance sheet stacking and feeding of a wide variety of sheet sizes.
Claim 6
Dependent Claim
19 words
The stacker-feeder of claim 1, wherein said paper tray includes air concentrator means at the rear of said tray.
Claim 7
Dependent Claim
36 words
The stacker-feeder of claim 5, wherein said air concentrator includes openings to allow air to escape through the rear of said tray and a series of point surfaces that resist rearward movement of the sheet stack.
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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) | 1989-02-17 | 1989-08-19 | 1990-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-17 | 1993-08-19 | 1994-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-17 | 1997-08-19 | 1998-02-18 | $7700.00 | Window Closed / Lapsed |