US4018187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grooved magnetic brush roll
Assignee: International Business Machines Corp
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Filing: 1976-06-30
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Granted: 1977-04-19
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Expires: 1996-06-30
Abstract
Abstract For use in an electrophotographic copy machine utilizing magnetic brush roll development, an improved hollow magnetic roll made of non-magnetic material containing axially located grooves along the exterior periphery. The grooves are spaced in a range from 15-25 times the diameter of the permeable carrier beads used in the development process and the lands between grooves are polished to a high degree, e.g., 25 μ inches. The depth of the grooves is to a minimum of 1-2 times bead diameter while the groove width is to a minimum of 2-3 times bead diameter.
Inventors
- 👤 Jerry Joe Abbott
- 👤 Allison Holland Caudill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:38
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921; G03G15/0928; G03G2215/00; G03G2215/06; G03G2215/0602; G03G2215/0604; G03G2215/0607; G03G2215/0634; G03G2215/0636
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
A magnetic brush developer wherein a developer material comprising a toner coated magnetic carrier is supplied to a rotating magnetic brush roll to be conveyed by said roll to an elevated development zone, said roll comprising: a rotatably mounted hollow roll; magnetic means disposed within said hollow roll for creating a magnetic field in the path of the periphery of said roll; means to bring said developer material into contact with the roll surface; said roll surface containing axially located grooves spaced apart in a range from 15-25 times the diameter of said carrier.
Claim 2
Dependent Claim
94 words
A magnetic brush developer wherein a developer material comprising a toner coated magnetic carrier is supplied to a rotating magnetic brush roll to be conveyed by said roll to an elevated development zone, said roll comprising: a rotatably mounted hollow roll; magnetic means disposed within said hollow roll for creating a magnetic field in the path of the periphery of said roll; means to bring said developer material into contact with the roll surface; said roll surface containing axially located grooves spaced apart in a range from 15-25 times the diameter of said carrier.
Claim 3
Dependent Claim
21 words
The developer of claim 1 wherein said grooves are of a minimum width of 2-3 times the diameter of said carrier.
Claim 4
Dependent Claim
21 words
The developer of claim 2 wherein said grooves are of a minimum depth of 1-2 times the diameter of said carrier.
Claim 5
Dependent Claim
30 words
The developer of claim 1 wherein said roll is cylindrical in shape with polished land surfaces between grooves to provide a smooth surface for supporting said developer material between grooves.
Claim 6
Dependent Claim
15 words
The developer of claim 4 wherein said hollow roll is electrically conductive throughout its entirety.
Claim 7
Dependent Claim
21 words
The developer of claim 5 wherein said grooves are of a minimum width of 2-3 times the diameter of said carrier.
Claim 8
Dependent Claim
21 words
The developer of claim 6 wherein said grooves are of a minimum depth of 1-2 times the diameter of said carrier.
References Cited (Backward Citations)
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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) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |