US4457253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Critical temperature indicator
Assignee: William Carter Co
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Filing: 1982-11-09
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Granted: 1984-07-03
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Expires: 2002-11-09
Abstract
Abstract A critical temperature indicator is provided utilizing the volume reduction characteristics of organic compounds as they undergo a change from the liquid state to the solid state. A capillary tube sealed at one end contains a first organic compound adjacent the closed end and a second colored organic compound which has a solidification temperature lower than that of the first compound and which is separated from the first compound by a liquid which is immiscible with either the first or the second compounds. The separating liquid also has a solidification temperature lower than that of the first compound. A colorless or white porous plug is located within the separating liquid and frictionally engages the tube to prevent movement of the plug with respect to the tube. The volume of the separating liquid is such that contact between the colored compound and the plug is prevented prior to solidification of the first compound and solidification of the first compound draws the colored compound into the plug to color the plug and provide a visual indication that the first compound has solidified.
Inventors
- 👤 Wendell J. Manske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:48
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
185 words
A critical temperature indicator comprising: a capillary tube closed at one end; a first liquid extending from said closed end partially throughout said tube which is capable of solidification and exhibits the property of volume reduction upon solidification; a colored second liquid located within said tube which has a solidification temperature lower than that of said first liquid; a separating liquid interposed between said first and second liquids which is immiscible with either of said first or second liquids to prevent mixing thereof and which has a solidification temperature lower than that of said first liquid; and a porous plug capable of sorbing said second liquid located within said separating liquid and frictionally engaging said tube to prevent movement of said plug with respect to said tube; the volumes of said first liquid and said separating liquid being such that contact between said second liquid and said plug is prevented prior to solidification of said first liquid and solidification of said first liquid draws said second liquid into said plug to color said plug and provide a visual indication that said first liquid has solidified.
Claim 2
Dependent Claim
185 words
A critical temperature indicator comprising: a capillary tube closed at one end; a first liquid extending from said closed end partially throughout said tube which is capable of solidification and exhibits the property of volume reduction upon solidification; a colored second liquid located within said tube which has a solidification temperature lower than that of said first liquid; a separating liquid interposed between said first and second liquids which is immiscible with either of said first or second liquids to prevent mixing thereof and which has a solidification temperature lower than that of said first liquid; and a porous plug capable of sorbing said second liquid located within said separating liquid and frictionally engaging said tube to prevent movement of said plug with respect to said tube; the volumes of said first liquid and said separating liquid being such that contact between said second liquid and said plug is prevented prior to solidification of said first liquid and solidification of said first liquid draws said second liquid into said plug to color said plug and provide a visual indication that said first liquid has solidified.
Claim 3
Dependent Claim
18 words
A critical temperature indicator according to claim 1 further including a dye in solution with said second liquid.
Claim 4
Dependent Claim
15 words
A critical temperature indicator according to claim 2 wherein said dye is Waxolene Violet BA.
Claim 5
Dependent Claim
17 words
A critical temperature indicator according to claim 1 wherein said first and second liquids are organic compounds.
Claim 6
Dependent Claim
18 words
A critical temperature indicator according to claim 4 wherein said first and second liquids are fatty acid esters.
Claim 7
Dependent Claim
50 words
A critical temperature indicator according to claim 4 wherein said first liquid is selected from a group consisting of octyl caprylate, heptyl caprylate, hexyl laurate, octyl caprate, butyl myristate, isopropyl myristate, decyl caprate, ethyl myristate, isopropyl palmitate, lauryl caprate, butyl stearate, decyl myristate, octadecyl acetate, lauryl palmitate, and cetyl palmitate.
Claim 8
Dependent Claim
54 words
A critical temperature indicator according to claim 4 wherein said second liquid is selected from a group consisting of octyl caprylate, heptyl caprylate, hexyl laurate, octyl caprate, butyl myristate, isopropyl myristate, decyl caprate, ethyl myristate, isopropyl palmitate, lauryl caprate, butyl stearate, decyl myristate, octadecyl acetate, lauryl palmitate, cetyl palmitate, trioctyl phosphate, and bis(2-ethylhexyl) phthalate.
Claim 9
Dependent Claim
18 words
A critical temperature indicator according to claim 7 further including a dye in solution with said second liquid.
Claim 10
Dependent Claim
15 words
A critical temperature indicator according to claim 8 wherein said dye is Waxolene Violet BA.
Claim 11
Dependent Claim
17 words
A critical temperature indicator according to claim 1 wherein said separating liquid is an aqueous salt solution.
Claim 12
Dependent Claim
39 words
A critical temperature indicator according to claim 10 wherein said salt is selected from the group consisting of ammonium chloride, calcium chloride, iron chloride, lithium chloride, potassium bromide, potassium chloride, potassium iodide, sodium bromide, sodium chloride or sodium nitrate.
Claim 13
Dependent Claim
15 words
A critical temperature indicator according to claim 1 wherein said separating liquid is a perfluorocarbon.
Claim 14
Dependent Claim
22 words
A critical temperature indicator according to claim 1 wherein said separating liquid is a saturated solution of nickel II nitrate in water.
Claim 15
Dependent Claim
16 words
A critical temperature indicator according to claim 1 wherein said porous pad is a non-woven material.
Claim 16
Dependent Claim
13 words
A critical temperature indicator according to claim 14 wherein said material is polypropylene.
Claim 17
Dependent Claim
15 words
A critical temperature indicator according to claim 14 wherein said material is blown micro-fiber polypropylene.
References Cited (Backward Citations)
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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) | 1987-07-03 | 1988-01-02 | 1988-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-03 | 1992-01-02 | 1992-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-03 | 1996-01-02 | 1996-07-03 | $7700.00 | Window Closed / Lapsed |