US3927640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer shut-off apparatus
Assignee: Xerox Corp
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Filing: 1974-04-29
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Granted: 1975-12-23
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Expires: 1994-04-29
Abstract
Abstract A developer sump is communicated to a magnetic transport means through a developer outlet at the lower end of the sump. During development function, magnetic developer flows from the sump through the outlet to the magnetic transport means. A magnetic gate is normally located away from the outlet during the development function and is arranged to be swung into a position adjacent to the opening to magnetically stop the flow of developer through the outlet when it is desired to purge the development system.
Inventors
- 👤 Richard E Smith
- 👤 Raymond W Stover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:55
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
202 words
In a development system: A surface capable of having a developable image thereon, a developer housing including a developer sump, said sump having ferromagnetic developer therein, magnetic means located within said housing for presenting said developer to said surface, a developer outlet at the lowermost portion of said sump, said developer flowing through said outlet to said means for presenting said developer to said surface, and magnetic gate means located entirely exterior said housing for selectively either magnetically blocking the entire flow of developer through said outlet when in a closed position or for allowing flow of developer through said outlet when in an open position, said magnetic gate means comprising a member having permanent magnet means secured thereto at one end and pivotally mounted to said housing at the other end for pivotal movement between said open and closed positions, and means for pivoting said member in one direction to move said permanent magnet means into said closed position adjacent said outlet to block the entire flow of developer through said outlet and for pivoting said member in the opposite direction to move said magnet away from said outlet to said open position to allow flow of developer through said outlet.
Claim 2
Dependent Claim
202 words
In a development system: A surface capable of having a developable image thereon, a developer housing including a developer sump, said sump having ferromagnetic developer therein, magnetic means located within said housing for presenting said developer to said surface, a developer outlet at the lowermost portion of said sump, said developer flowing through said outlet to said means for presenting said developer to said surface, and magnetic gate means located entirely exterior said housing for selectively either magnetically blocking the entire flow of developer through said outlet when in a closed position or for allowing flow of developer through said outlet when in an open position, said magnetic gate means comprising a member having permanent magnet means secured thereto at one end and pivotally mounted to said housing at the other end for pivotal movement between said open and closed positions, and means for pivoting said member in one direction to move said permanent magnet means into said closed position adjacent said outlet to block the entire flow of developer through said outlet and for pivoting said member in the opposite direction to move said magnet away from said outlet to said open position to allow flow of developer through said outlet.
Claim 3
Dependent Claim
24 words
The structure as recited in claim 1 wherein said surface is a photoconductive surface and said developer comprises toner particles and ferromagnetic carrier particles.
Claim 4
Dependent Claim
22 words
The structure as recited in claim 2 wherein said magnetic means comprises rotatable rollers of non-magnetic material each surrounding a magnetic member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |