US3593842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powder level sensing
Assignee: 3M Co
•
Filing: 1969-10-20
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Granted: 1971-07-20
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Expires: 1989-10-20
Abstract
Abstract Apparatus for sensing and externally signalling the diminution of a supply of developer powder in a tray in which a blunt edged conductive bar is supported by resilient members from a rotating shaft to drag the powder toward a discharge opening and which completes an electrical circuit by touching contacts in the bottom wall of the tray upon diminution of the supply of developer powder to close a circuit and externally signal the diminution of the powder.
Inventors
- 👤 Richard C Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:16
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0856
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
167 words
Apparatus for use with a supply tray having a bottom wall for sensing the diminution of a supply of developer powder in said tray, said apparatus comprising: a shaft rotatably mounted above said bottom wall, means for rotating said shaft, spaced electrical contact means on said bottom wall of said supply tray, a conductive bar having a blunt surface to restrict penetration of said bar when contacting a said supply of developer powder while affording movement of said supply of powder in the direction of movement of said bar, resilient means for connecting said bar to said shaft to provide movement of said bar about the axis of said shaft and for permitting said bar to float on a said supply of powder and to contact said contact means upon diminution of a said supply of developer powder above said contact means, and signal means responsive to contact of said bar and said electrical contact means for indicating the diminution of a said supply of developer powder.
Claim 2
Dependent Claim
167 words
Apparatus for use with a supply tray having a bottom wall for sensing the diminution of a supply of developer powder in said tray, said apparatus comprising: a shaft rotatably mounted above said bottom wall, means for rotating said shaft, spaced electrical contact means on said bottom wall of said supply tray, a conductive bar having a blunt surface to restrict penetration of said bar when contacting a said supply of developer powder while affording movement of said supply of powder in the direction of movement of said bar, resilient means for connecting said bar to said shaft to provide movement of said bar about the axis of said shaft and for permitting said bar to float on a said supply of powder and to contact said contact means upon diminution of a said supply of developer powder above said contact means, and signal means responsive to contact of said bar and said electrical contact means for indicating the diminution of a said supply of developer powder.
Claim 3
Dependent Claim
29 words
Apparatus as recited in claim 1 wherein said resilient means comprises a plurality of helical springs normally extending from said shaft generally perpendicular to the axis of said shaft.
Claim 4
Dependent Claim
26 words
Apparatus as recited in claim 2 wherein said conductive bar is cylindrical and said springs normally support said bar parallel to the axis of said shaft.
Claim 5
Dependent Claim
156 words
Apparatus for use with a supply tray having a bottom wall for sensing and signalling the diminution of a supply of developer powder in said tray, said apparatus comprising: a shaft rotatably mounted above said bottom wall, means for rotating said shaft, a bar having a blunt surface to restrict penetration of said bar when contacting a said supply of developer powder while affording movement of said supply of powder in the direction of movement of said bar, resilient means for connecting said bar to said shaft to provide movement of said bar with said shaft about the axis of said shaft, to permit said bar to float on said supply of powder and to increase the displacement of said bar from said shaft upon diminution of said supply of developer powder, and signal means responsive to increased displacement of said bar from said shaft for indicating the diminution of a said supply of developer powder.
Claim 6
Dependent Claim
156 words
Apparatus for use with a supply tray having a bottom wall for sensing and signalling the diminution of a supply of developer powder in said tray, said apparatus comprising: a shaft rotatably mounted above said bottom wall, means for rotating said shaft, a bar having a blunt surface to restrict penetration of said bar when contacting a said supply of developer powder while affording movement of said supply of powder in the direction of movement of said bar, resilient means for connecting said bar to said shaft to provide movement of said bar with said shaft about the axis of said shaft, to permit said bar to float on said supply of powder and to increase the displacement of said bar from said shaft upon diminution of said supply of developer powder, and signal means responsive to increased displacement of said bar from said shaft for indicating the diminution of a said supply of developer powder.
Claim 7
Dependent Claim
29 words
Apparatus as recited in claim 4 wherein said resilient means comprises a plurality of helical springs normally extending from said shaft generally perpendicular to the axis of said shaft.
Claim 8
Dependent Claim
25 words
Apparatus as recited in claim 5 wherein said bar is cylindrical and said springs normally support said bar parallel to the axis of said shaft.
Claim 9
Dependent Claim
49 words
Apparatus as recited in claim 4 wherein said bar is electrically conductive, wherein said signal means includes spaced electrical contact means, and wherein said resilient means connects said bar to said shaft to contact said bar against said contact means upon diminution of a said supply of developer powder.
References Cited (Backward Citations)
US2909766A
Cited
US2977772A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |