US4018061A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture indicator
Assignee: Motors Liquidation Co
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Filing: 1976-05-24
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Granted: 1977-04-19
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Expires: 1996-05-24
Abstract
Abstract A moisture indicator particularly adapted for use in a refrigerant system to indicate by visual inspection the moisture content of refrigerant therein. A preferred embodiment of the indicator comprises a hygroscopic plastic sleeve which is mounted behind a sight glass within a housing such as a receiver. The whole sleeve can be impregnated with a cobalt salt whose color changes when exposed to water. In use, the color of the indicator may be visually compared with a reference color stripe which does not change color with the addition of moisture and which is preferably applied adjacent the cobalt salt. The sleeve can also be non-hygroscopic plastic, or even metal, coated with a thin film of hygroscopic plastic containing cobalt salts.
Inventors
- 👤 Victor A. Williamitis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:52
CPC Classifications
F; F25; F25B; F25B43/00; F25B43/006; F25B41/00; F25B41/006; F25B43/003
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
A moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: an indicator base made from hygroscopic plastic material mounted within a housing of the refrigerant system in contact with the flow of refrigerant therethrough; a paint applied to the surface of said indicator base made up of a solution of a hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; a reference band of colored material on said indicator base adjacent to said painted surface for visual comparison with the color of said painted surface.
Claim 2
Dependent Claim
134 words
A moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: an indicator base made from hygroscopic plastic material mounted within a housing of the refrigerant system in contact with the flow of refrigerant therethrough; a paint applied to the surface of said indicator base made up of a solution of a hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; a reference band of colored material on said indicator base adjacent to said painted surface for visual comparison with the color of said painted surface.
Claim 3
Dependent Claim
169 words
A refrigerant component including a moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: a housing with a passage for refrigerant flow between an inlet and an outlet; means in said housing enabling an observer to visually examine said housing passage from outside said housing; an indicator base within said passage in the sight line of said examining means of said housing; said base being made of a hygroscopic plastic material; a portion of said base being treated with a paint made up of a solution of hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; a reference band of colored material on said base adjacent to said painted surface for visual comparison with the color of said painted surface.
Claim 4
Dependent Claim
169 words
A refrigerant component including a moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: a housing with a passage for refrigerant flow between an inlet and an outlet; means in said housing enabling an observer to visually examine said housing passage from outside said housing; an indicator base within said passage in the sight line of said examining means of said housing; said base being made of a hygroscopic plastic material; a portion of said base being treated with a paint made up of a solution of hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; a reference band of colored material on said base adjacent to said painted surface for visual comparison with the color of said painted surface.
Claim 5
Dependent Claim
146 words
A moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: an indicator base of a material which is stable in a refrigerant environment adapted to be mounted within a housing of the refrigerant system in contact with the flow of refrigerant therethrough; a paint applied to the surface of said indicator base made up of a solution of a hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; whereby said paint provides an erosion resistant coating resistant to fluid wear in which the fine particles of cobalt salt are dispersed and held in a substantially uniform distribution.
Claim 6
Dependent Claim
146 words
A moisture indicator for detecting the relative degree of water mixed with refrigerant in a refrigeration system comprising: an indicator base of a material which is stable in a refrigerant environment adapted to be mounted within a housing of the refrigerant system in contact with the flow of refrigerant therethrough; a paint applied to the surface of said indicator base made up of a solution of a hygroscopic plastic and a solvent and with finely divided particles of a cobalt salt therein whereby said paint is characterized by one color when in the absence of significant quantities of water and by a gradual color change to a second color with the presence of increasing quantities of water; whereby said paint provides an erosion resistant coating resistant to fluid wear in which the fine particles of cobalt salt are dispersed and held in a substantially uniform distribution.
References Cited (Backward Citations)
US3100691A
Cited
US3533277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |