US4191125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Freeze indicator
Assignee: PY MAH Corp
•
Filing: 1978-07-03
•
Granted: 1980-03-04
•
Expires: 1998-07-03
Abstract
Abstract There is provided a freeze indicator which includes a frangible ampule substantially filled with a mixture of water, a nucleating agent, and a surfactant. Upon reaching the freezing point of water, most of the water will freeze and expand, and fracture the frangible ampule. The nucleating agent has substantially similar molecular space grouping to frozen liquid to overcome the undercooling effect. The surfactant provides an increased surface area of contact between the water and the nucleating agent. The frangible ampule is in contact with a pad which has a water soluable dye printed on one side. When the ampule breaks, it releases some of the water, and the dye is wicked to one side of the pad by the water, showing a color change. In order to fine-tune the freeze indicator, varying amounts of deuterium oxide may be added to the water to raise its freezing point.
Inventors
- 👤 Claude D. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:02
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06; G01K11/12; Y; Y10; Y10S; Y10S252/00; Y10S252/962
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
124 words
A freeze indicator comprising: a frangible container, said container housing a liquid which expands upon freezing, thereby fracturing said container, said liquid having a nucleating agent disbursed therein, said nucleating agent being substantially insoluble in said liquid, liquid responsive indicator means, said nucleating agent and said liquid having substantially similar molecular space groupings whereby undercooling of said liquid is substantially prevented; said container further housing a surfacant which is mixed with said liquid and said nucleating agent before freezing of said liquid for providing increased contact between said nucleating agent and said liquid and further providing a decrease in surface tension between said container, when fractured, and said liquid whereby a substantial immediate indication of freezing is provided on said liquid responsive indicating means.
Claim 2
Dependent Claim
124 words
A freeze indicator comprising: a frangible container, said container housing a liquid which expands upon freezing, thereby fracturing said container, said liquid having a nucleating agent disbursed therein, said nucleating agent being substantially insoluble in said liquid, liquid responsive indicator means, said nucleating agent and said liquid having substantially similar molecular space groupings whereby undercooling of said liquid is substantially prevented; said container further housing a surfacant which is mixed with said liquid and said nucleating agent before freezing of said liquid for providing increased contact between said nucleating agent and said liquid and further providing a decrease in surface tension between said container, when fractured, and said liquid whereby a substantial immediate indication of freezing is provided on said liquid responsive indicating means.
Claim 3
Dependent Claim
35 words
An indicator as set forth in claim 1 wherein said nucleating agent is taken from the group consisting of cupric sulfide, ferrous sulfide, zinc metal, molybdenum sulfide, tungsten sulfide, beryllium aluminum silicate, and silver iodide.
Claim 4
Dependent Claim
34 words
An indicator as set forth in claim 1 further including a protective package housing said frangible container, said protective package including a preformed, semi-rigid blister enclosing at least a portion of said frangible container.
Claim 5
Dependent Claim
40 words
An indicator as set forth in claim 1 wherein said frangible container is filled with said liquid to the extent that a void space is provided large enough to prevent breakage of heating but small to permit breakage upon freezing
Claim 6
Dependent Claim
16 words
An indicator as set forth in claim 4 wherein said frangible container includes a constricted neck
Claim 7
Dependent Claim
16 words
An indicator as set forth in claim 1 wherein said surfactant is polyoxyethylene 20 sorbitan monooleate.
Claim 8
Dependent Claim
29 words
An indicator as set forth in claim 1 wherein said liquid is taken from the group consisting essentially of water (H 2 O) and deuterium oxide (D 2 O).
Claim 9
Dependent Claim
32 words
An indicator as set forth in claim 1 wherein said liquid is a mixture of water (H 2 O) and deuterium oxide (D 2 O) for providing a predetermined freeze point indication.
Claim 10
Dependent Claim
50 words
An indicator as set forth in claim 8 wherein the amount of water is within the range of two to ninety-eight percent (2%-98%) of the total volume of the liquid and deuterium oxide is within the range of ninety-eight to two percent (98%-2%) of the total volume of the liquid.
Claim 11
Dependent Claim
130 words
A freeze indicator comprising: a frangible container, said container housing a liquid which expands upon freezing, thereby fracturing said container; said liquid including a mixture of water (H 2 O) and deuterium oxide (D 2 O); said container further housing a nucleating agent and a surfactant, said surfactant being mixed with said liquid before freezing for providing increased contact between said nucleating agent and said liquid and further providing a decrease in surface tension between said container, when fractured, and said liquid, whereby a substantial immediate indication of freezing is provided; an indicator responsive to said liquid being in close association with said frangible container; said indicator providing an indication of freeze at a predetermined temperature as determined by the percent composition of the mixture of deuterium oxide and water.
Claim 12
Dependent Claim
130 words
A freeze indicator comprising: a frangible container, said container housing a liquid which expands upon freezing, thereby fracturing said container; said liquid including a mixture of water (H 2 O) and deuterium oxide (D 2 O); said container further housing a nucleating agent and a surfactant, said surfactant being mixed with said liquid before freezing for providing increased contact between said nucleating agent and said liquid and further providing a decrease in surface tension between said container, when fractured, and said liquid, whereby a substantial immediate indication of freezing is provided; an indicator responsive to said liquid being in close association with said frangible container; said indicator providing an indication of freeze at a predetermined temperature as determined by the percent composition of the mixture of deuterium oxide and water.
Claim 13
Dependent Claim
39 words
An indicator as set forth in claim 10 further including a nucleating agent added to said liquid, said nucleating agent having a substantially similar molecular space grouping with said frozen liquid whereby undercooling of said liquid is substantially prevented.
Claim 14
Dependent Claim
35 words
A device as set forth in claim 11 wherein said nucleating agent is taken from the group consisting of cupric sulfide, ferrous sulfide, zinc metal, molybdenum sulfide, tungsten sulfide, beryllium aluminum silicate, and silver iodide.
Claim 15
Dependent Claim
44 words
An indicator as set forth in claim 10 wherein the percentage by weight of water is between two and ninety-eight percent (2%-98%) of said liquid and the percentage by weight of deuterium oxide is between ninety-eight percent and two percent (98%-2%) of said liquid.
References Cited (Backward Citations)
US3127107A
Cited
US3056556A
Cited
US2903188A
Cited
US3055759A
Cited
US3414415A
Cited
US3596476A
Cited
US3760598A
Cited
US3545400A
Cited
US3826141A
Cited
US3946612A
Cited
US3980581A
Cited
US3956153A
Cited
US4145918A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |