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US3787706A
Expired / Lapsed
US
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Apparatus for the control of charge on a moving web
Assignee: Agfa Gevaert NV
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Filing: 1971-05-03
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Granted: 1974-01-22
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Expires: 1991-05-03
Abstract
Abstract A method for controlling electrostatic charges on a web, wherein the web is pulled over a metal roller which is connected to a D.C. voltage supply, the electrostatic field of the web is measured, and the voltage supply is controlled as a function of the measured field to produce a voltage of a polarity whereby the electrostatic field produced by the web is greatly neutralized.
Inventors
- 👤 W Degeest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:49
CPC Classifications
H; H05; H05F; H05F3/00; H05F3/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
169 words
Apparatus for reducing the electrostatic charge on a web moving along a path which comprises: a. a conductive electrode roller having a smooth rigid surface and disposed along said web path with the surface theReof in direct contact with one surface of said web, said electrode roller being electrically insulated from ground, b. a source of variable D.C. potential connected to said electrode roller, c. means for measuring the electrostatic field produced by the web at a locus adjacent said electrode roller and producing a signal corresponding to the magnitude of an electrostatic charge on said web, and d. a controller for said D.C. source, said controller receiving said signal from said field measuring means and controlling said source to apply to said electrode roller a D.C. potential of a polarity opposite to the measured field and a magnitude sufficient to substantially reduce the charge on the web, said web having the opposite surface thereof free of contact with an electrode roller in the region of said conductive roller.
Claim 2
Dependent Claim
169 words
Apparatus for reducing the electrostatic charge on a web moving along a path which comprises: a. a conductive electrode roller having a smooth rigid surface and disposed along said web path with the surface theReof in direct contact with one surface of said web, said electrode roller being electrically insulated from ground, b. a source of variable D.C. potential connected to said electrode roller, c. means for measuring the electrostatic field produced by the web at a locus adjacent said electrode roller and producing a signal corresponding to the magnitude of an electrostatic charge on said web, and d. a controller for said D.C. source, said controller receiving said signal from said field measuring means and controlling said source to apply to said electrode roller a D.C. potential of a polarity opposite to the measured field and a magnitude sufficient to substantially reduce the charge on the web, said web having the opposite surface thereof free of contact with an electrode roller in the region of said conductive roller.
Claim 3
Dependent Claim
17 words
Apparatus according to claim 6 wherein said field measuring means is disposed downstream of said electrode roller.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |