Patent US4984778A successfully refreshed from Google Patents.
US4984778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet feeder with skew control
Assignee: Xerox Corp
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Filing: 1989-03-23
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Granted: 1991-01-15
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Expires: 2009-03-23
Abstract
Abstract An apparatus for feeding sheets has a surface over which a sheet may be fed, a sheet feeder for feeding sheets over the surface having a centerline of feed parallel to the direction of sheet feeding and at least one idler roll to inhibit skewing of a sheet being fed by the sheet feeder which is mounted for rotational contact with a sheet being fed on the centerline of the sheet feeder whereby a torque is not imparted to a sheet being fed in either the clockwise direction. The idler roll has a high frictional contact surface and is mounted to provide a low drag force in the feeding direction and a high lateral drag force to inhibit a sheet being fed from skewing.
Inventors
- 👤 Thomas R. Alexander
- 👤 Donato D. Evangelista
- 👤 Michael F. Leo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:35
CPC Classifications
B; B65; B65H; B65H5/00; B65H5/06; B65H5/062; B65H2301/00; B65H2301/30; B65H2301/33; B65H2301/331
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
142 words
Apparatus for feeding sheets comprising a surface over which a sheet may be fed, means for feeding sheets over said surface, said feeding means having a centerline of feed parallel to the direction of sheet feeding and at least one means to inhibit skewing of a sheet being fed by said feed means over said surface comprising an idler roll mounted for rotational contact with a sheet being fed on the centerline of the feed means whereby a torque is not imparted to a sheet being fed in either the clockwise or counterclockwise direction when the feed means imparts no torque to a sheet being fed, said idler roll having a high frictional contact surface and being mounted to provide a low drag force in the feeding direction and a high lateral drag force to inhibit a sheet being fed from skewing.
Claim 2
Dependent Claim
142 words
Apparatus for feeding sheets comprising a surface over which a sheet may be fed, means for feeding sheets over said surface, said feeding means having a centerline of feed parallel to the direction of sheet feeding and at least one means to inhibit skewing of a sheet being fed by said feed means over said surface comprising an idler roll mounted for rotational contact with a sheet being fed on the centerline of the feed means whereby a torque is not imparted to a sheet being fed in either the clockwise or counterclockwise direction when the feed means imparts no torque to a sheet being fed, said idler roll having a high frictional contact surface and being mounted to provide a low drag force in the feeding direction and a high lateral drag force to inhibit a sheet being fed from skewing.
Claim 3
Dependent Claim
19 words
The sheet feeding apparatus of claim 1 wherein said means to inhibit skewing is upstream of said feeding means.
Claim 4
Dependent Claim
19 words
The sheet feeding apparatus of claim 1 wherein said means to inhibit skewing is downstream of said feeding means.
Claim 5
Dependent Claim
20 words
The sheet feeding apparatus of claim 2 further including a second means to inhibit skewing downstream of said feeding means.
Claim 6
Dependent Claim
45 words
The sheet feeding apparatus of claim 1 wherein said surface over which a sheet may be fed is a planar feed table with a side edge guide parallel to the feeding direction at one end of said feed table to guide a sheet being fed.
Claim 7
Dependent Claim
32 words
The sheet feeding apparatus of claim 5 wherein said side edge guide is positioned a fixed lateral distance from the centerline of feed to provide a side registration of sheets being fed.
Claim 8
Dependent Claim
30 words
The sheet feeding apparatus of claim 5 wherein said side edge guide is movable relative to said feed table and said feeding means is fixed relative to said feed table.
Claim 9
Dependent Claim
37 words
The sheet feeding apparatus of claim 1 wherein the distance in the feeding direction between the feeding means and the idler roll is less than the dimension in the feeding direction of a sheet to be fed.
Claim 10
Dependent Claim
28 words
The sheet feeding apparatus of claim 1 wherein the idler roll has a coefficient of friction with the sheet being fed of from about 1.5 to about 1.75.
Claim 11
Dependent Claim
29 words
The sheet feeding apparatus of claim 1 wherein the idler roll provides a normal force on a sheet being fed of from about 30 grams to about 70 grams.
Claim 12
Dependent Claim
76 words
The sheet feeding apparatus of claim 1 wherein the feeding means is a top feeding friction retard feeder comprising a retard pad on the surface over which a sheet may be fed and two feed rolls rotatable in the feeding direction and forming a separating feeding nip with said retard pad, said rolls being axially spaced on an axis perpendicular to the feeding direction, and wherein the centerline of feed is midway between the feed rolls.
Claim 13
Dependent Claim
69 words
The sheet feeding apparatus of claim 11 further including two nudger rolls rotatable in the feeding direction and axially spaced on an axis perpendicular to the feeding direction and wherein the centerline of feed is midway between the nudger rolls, said nudger rolls being positioned upstream of said nip between the feed rolls and the retard pad and which on rotation urge a sheet being fed into said nip.
Claim 14
Dependent Claim
19 words
The sheet feeding apparatus of claim 12 wherein said means to inhibit skewing is upstream of said feeding means.
Claim 15
Dependent Claim
19 words
The sheet feeding apparatus of claim 12 wherein said means to inhibit skewing is downstream of said feeding means.
Claim 16
Dependent Claim
20 words
The sheet feeding apparatus of claim 14 further including a second means to inhibit skewing downstream of said feeding means.
Claim 17
Dependent Claim
45 words
The sheet feeding apparatus of claim 12 wherein said surface over which a sheet may be fed is a planar feed table with a side edge guide parallel to the feeding direction at one end of said feed table to guide a sheet being fed.
Claim 18
Dependent Claim
32 words
The sheet feeding apparatus of claim 16 wherein said side edge guide is positioned a fixed lateral distance from the centerline of feed to provide a side registration of sheets being fed.
Claim 19
Dependent Claim
37 words
The sheet feeding apparatus of claim 12 wherein the distance in the feeding direction between the feeding means and the idler roll is less than the dimension in the feeding direction of a sheet to be fed.
Claim 20
Dependent Claim
27 words
The sheet feeding apparatus of claim 12 wherein the idler roll has a coefficient of friction with the sheet being of from about 1.5 to about 1.75.
Claim 21
Dependent Claim
29 words
The sheet feeding apparatus of claim 12 wherein the idler roll provides a normal force on a sheet being fed of from about 30 grams to about 70 grams.
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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) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |