US3753652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recording liquid flow over a solid surface
Assignee: Ilford Imaging Switzerland GmbH
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Filing: 1971-02-03
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Granted: 1973-08-21
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Expires: 1991-02-03
Abstract
Abstract This invention relates to a method of recording liquid flow over a solid surface: The solid surface is covered with a thin coating film which contains a diffusible substance. A liquid is caused to flow over the coated surface. The liquid contains in dissolved form a substance which reacts with said diffusible substance to yield a reaction product, preferably a colored reaction product, that is visible in the coating and sparingly soluble in the flowing liquid. The method is particularly useful for testing the conditions in photographic processing baths in a simple manner.
Inventors
- 👤 H Gassmann
- 👤 U Frauchiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:01
CPC Classifications
G; G01; G01N; G01N13/00; G01P; G01P5/00; G01P5/001
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
23 words
A method according to claim 1, wherein the material forming the coating can swell in the liquid, but is not dissolved by it.
Claim 2
Dependent Claim
41 words
A method according to claim 2, wherein the liquid is an aqueous solution and the maTerial forming the coating is a hydrophilic compound of high molecular weight that can swell in water but is insoluble in water at the application temperature.
Claim 3
Dependent Claim
12 words
A method according to claim 3 wherein the hydrophilic compound is gelatin.
Claim 4
Dependent Claim
23 words
A method according to claim 4 wherein the gelatin coating contains a hardening agent to reduce its swelling capacity in the flowing liquid.
Claim 5
Dependent Claim
32 words
A method according to claim 1 wherein the reactive substances incorporated in the coating and dissolved in the liquid are compounds which react to form an azo dyestuff insoluble in the liquid.
Claim 6
Dependent Claim
34 words
A method according to claim 1 wherein the reaction substances incorporated in the coating and dissolved in the liquid are inorganic compounds which react together to form a reaction product insoluble in the liquid.
Claim 7
Dependent Claim
41 words
A method according to claim 7 wherein the substance incorporated in the coating is a soluble ferricyanide or ferrocyanide of an alkali metal and the substance dissolved in the liquid is a water-soluble salt of a bivalent or trivalent heavy metal.
Claim 8
Dependent Claim
24 words
A method according to claim 1, in which film, or paper is used as a carrier for the thin coating of the film-forming substance.
Claim 9
Independent Claim
88 words
A method for testing the flow conditions in a photographic processing machine which comprises covering the surface of a photographic substrate with a thin coating of a film which contains a freely diffusible substance and flowing over the coated surface a liquid which contains, dissolved therein, a substance which reacts with the diffusible substance to yield a reaction product that is visible in the coating and does not dissolve easily in the flowing liquid, the color density of the reaction product increasing with increased rate of liquid flow.
Claim 10
Independent Claim
80 words
A method for testing the flow conditions in a photographic processing machine which comprises coating the surface of a photographic substrate with a thin coating of a film containing potassium ferricyanide, and flowing over the coated surface a liquid containing a ferrous salt dissolved therein, to yield a colored reaction product that is visible in the coating and does not dissolve easily in the flowing liquid, the color density of the reaction product increasing with increased rate of liquid flow.
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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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |