Patent US4292924A successfully refreshed from Google Patents.
US4292924A
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Magnetic brush apparatus
Assignee: Xerox Corp
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Filing: 1979-10-03
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Granted: 1981-10-06
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Expires: 1999-10-03
Abstract
Abstract A magnetic brush apparatus which minimizes the escape of toner and/or carrier particles by means of a magnetic field shaping device which minimizes the presence of magnetic lines of force projecting axially outward from the magnetic brush rollers. Examples of magnetic field shaping devices are a piece of ferro-magnetic material and a magnetic field shaping magnet.
Inventors
- 👤 Nero R. Lindblad
- 👤 Ivan Rezanka
- 👤 John V. Cassidy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A magnetic brush apparatus for use in an electrostatographic printing machine, including: a tubular member journaled for rotation about the longitudinal axis thereof; a magnetic member mounted stationarily and interiorly of said tubular member, said magnetic member generating a radial magnetic field extending outwardly therefrom in a direction substantially normal to the longitudinal axis of said tubular member and an axial magnetic field extending outwardly from opposed ends of said magnetic member in a direction substantially parallel to the longitudinal axis of said tubular member; and means, positioned radially interiorly of said tubular member in the region of opposed ends of said magnetic member and cooperating therewith, for substantially suppressing the axial magnetic field.
Claim 2
Dependent Claim
114 words
A magnetic brush apparatus for use in an electrostatographic printing machine, including: a tubular member journaled for rotation about the longitudinal axis thereof; a magnetic member mounted stationarily and interiorly of said tubular member, said magnetic member generating a radial magnetic field extending outwardly therefrom in a direction substantially normal to the longitudinal axis of said tubular member and an axial magnetic field extending outwardly from opposed ends of said magnetic member in a direction substantially parallel to the longitudinal axis of said tubular member; and means, positioned radially interiorly of said tubular member in the region of opposed ends of said magnetic member and cooperating therewith, for substantially suppressing the axial magnetic field.
Claim 3
Dependent Claim
17 words
A magnetic brush apparatus of claim 1, wherein said magnetic member includes a plurality of permanent magnets.
Claim 4
Dependent Claim
28 words
A magnetic brush apparatus of claims 2 or 1 wherein said suppressing means includes a ferro-magnetic member disposed in the region of the end of said magnetic member.
Claim 5
Dependent Claim
15 words
A magnetic brush apparatus of claim 3 wherein said ferro-magnetic member is cold rolled steel.
Claim 6
Dependent Claim
50 words
A magnetic brush apparatus of claims 2 or 11, wherein said suppressing means includes a suppression magnet spaced from the end of said magnetic member and having the polarity of the magnetic poles thereof arranged in the same direction as the polarity of the magnetic poles of said magnetic member.
Claim 7
Dependent Claim
25 words
A magnetic brush apparatus of claim 5 wherein said suppression magnet is axially spaced from the end of said magnetic member by a ferro-magnetic member.
Claim 8
Dependent Claim
29 words
A magnetic brush apparatus of claim 5 wherein said suppression magnet is axially spaced from the end of said magnet member by an air gap and a ferro-magnetic member.
Claim 9
Dependent Claim
29 words
A magnetic brush apparatus of claim 5 wherein said suppression magnet is axially spaced from the end of said magnetic member by a non-magnetizeable member and a ferro-magnetic member.
Claim 10
Dependent Claim
16 words
A magnetic brush apparatus of claim 8 wherein said non-magnetizeable member is paper or a plastic.
References Cited (Backward Citations)
US3939801A
Cited
US3915121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |