US4265431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for washing developed photographic and like films
Assignee: FOTOMEC SAN MARCO SpA AN ITALIAN Co
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Filing: 1979-05-14
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Granted: 1981-05-05
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Expires: 1999-05-14
Abstract
Abstract For recovering silver and discharging depolluted wastes from washing baths for photographic and like films or papers, a method is disclosed which consists in having the washing liquid running in countercurrent relationship in a number of serially arranged tubs, relative to the direction of advance of the photographic material being washed. The concentration of silver salts is thus increased in a direction contrary to that of advance of the sensitive materials being processed so that the first tub of the series (considered in the machine direction) has such a concentration of silver that the recovery by any methods is economically interesting.
Inventors
- 👤 Lodovico Falomo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:31
CPC Classifications
G; G03; G03D; G03D3/00; G03D3/02; G03D3/06; G03D3/065; G03C; G03C5/00; G03C5/26; G03C5/395
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
Apparatus for treating a material with washing liquid to remove a soluble constituent from the material by washing, said apparatus comprising: a plurality of washing tubs including a first tub, a last tub and at least one intermediate tub; means for conveying the material through all of said tubs in sequence beginning with the first tub; overflow passages for the washing liquid between each tub and the next; means for feeding fresh washing liquid to the last tub; means for discharging washing liquid from the first tub; and control means responsive to the concentration of solutes in the last tub for controlling said feeding means in a mode to feed liquid when the concentration exceeds a preselected value whereby the volume of washing liquid is minimized.
Claim 2
Dependent Claim
126 words
Apparatus for treating a material with washing liquid to remove a soluble constituent from the material by washing, said apparatus comprising: a plurality of washing tubs including a first tub, a last tub and at least one intermediate tub; means for conveying the material through all of said tubs in sequence beginning with the first tub; overflow passages for the washing liquid between each tub and the next; means for feeding fresh washing liquid to the last tub; means for discharging washing liquid from the first tub; and control means responsive to the concentration of solutes in the last tub for controlling said feeding means in a mode to feed liquid when the concentration exceeds a preselected value whereby the volume of washing liquid is minimized.
Claim 3
Dependent Claim
16 words
Apparatus as in claim 1 including means for recycling and stirring the liquid in each tub.
Claim 4
Dependent Claim
25 words
Apparatus as in claim 1 including means for recovering a desired dissolved constituent from the liquid discharged from the first tub by said discharge means.
Claim 5
Dependent Claim
13 words
Apparatus as in claim 3 wherein said recovery means is a silver-recovery means.
Claim 6
Dependent Claim
162 words
Apparatus for washing sheet material made sensitive to light by an emulsion containing silver salts, after the sheet material has been developed and fixed, said apparatus comprising: a plurality of washing tubs including a first tub; a last tub and at least one intermediate tub; means for conveying the sheet material through all of the tubs in sequence beginning with the first tub; means for feeding fresh washing liquid to the last tub; overflow means between each tub and the next for passing washing liquid countercurrent to the direction of travel of the sheet material through the tubs and for maintaining a generally fixed level of washing liquid in those tubs upstream from the first tub; means for discharging washing liquid; and control means responsive to the concentration of solutes in the last tub controlling said feeding means in a mode to feed washing liquid when the concentration exceeds a preselected value thereby minimizing the volume of washing liquid which is required.
Claim 7
Dependent Claim
162 words
Apparatus for washing sheet material made sensitive to light by an emulsion containing silver salts, after the sheet material has been developed and fixed, said apparatus comprising: a plurality of washing tubs including a first tub; a last tub and at least one intermediate tub; means for conveying the sheet material through all of the tubs in sequence beginning with the first tub; means for feeding fresh washing liquid to the last tub; overflow means between each tub and the next for passing washing liquid countercurrent to the direction of travel of the sheet material through the tubs and for maintaining a generally fixed level of washing liquid in those tubs upstream from the first tub; means for discharging washing liquid; and control means responsive to the concentration of solutes in the last tub controlling said feeding means in a mode to feed washing liquid when the concentration exceeds a preselected value thereby minimizing the volume of washing liquid which is required.
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) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |