US3826141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature indicator
Assignee: Pymah Corp
•
Filing: 1972-08-02
•
Granted: 1974-07-30
•
Expires: 1992-08-02
Abstract
Abstract Temperature indicators are provided comprising a heat-conductive carrier having at least one, but preferably a plurality of regions (cavities) thereon, each region containing a thermally responsive substance which undergoes a change of state at a precise and predetermined temperature different from the temperature of the change of state of the thermally responsive substance in any other region. The temperatures at which such changes of state occur are detected visually by an indicator system which is intimately associated with the thermally responsive materials in these regions. The incorporation of certain organic compounds into the indicator system accelerates visual detection of such change of state, thus permitting rapid measurement of the temperature corresponding to the incipient fusion of the thermally responsive material in each region.
Inventors
- 👤 C Pickett
- 👤 D Chadha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:52
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06; G01K13/00; G01K13/20; Y; Y10; Y10S; Y10S252/00; Y10S252/962; Y10S428/00; Y10S428/913
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
In a temperature indicator comprising a heat conducting carrier sheet having a plurality of spaced regions defined therein, a like plurality of solid solutions of at least two organic compounds in varied composition ratios deposited in said regions, a single composition of said solid solutions being deposited in a single one of said regions, each of said solid solutions melting at a precise and predetermined temperature different from that at which the solid solution in any other region melts, and indicator means associated with the solid solutions deposited in each of said regions and operable to visually indicate the melting of any individual solid solution, the improvement comprising the incorporation of a surface-active agent selected from the group consisting of cationic, anionic and nonionic surfactants in said indicator means to accelerate said visual indication.
Claim 2
Dependent Claim
134 words
In a temperature indicator comprising a heat conducting carrier sheet having a plurality of spaced regions defined therein, a like plurality of solid solutions of at least two organic compounds in varied composition ratios deposited in said regions, a single composition of said solid solutions being deposited in a single one of said regions, each of said solid solutions melting at a precise and predetermined temperature different from that at which the solid solution in any other region melts, and indicator means associated with the solid solutions deposited in each of said regions and operable to visually indicate the melting of any individual solid solution, the improvement comprising the incorporation of a surface-active agent selected from the group consisting of cationic, anionic and nonionic surfactants in said indicator means to accelerate said visual indication.
Claim 3
Dependent Claim
81 words
A temperature indicator as defined in claim 1 wherein said indicator means comprises (a) an indicator layEr operable to receive said melted solid solution and impregnated with said surface active agent and a dye or pigment soluble in said solid solution and (b) an overlying absorbent layer masking, and having a color contrasting with, the color of the indicator layer but operable to assume the color of said indicator layer through absorption of melted solid solution carrying said dye or pigment.
Claim 4
Dependent Claim
18 words
A temperature indicator as defined in claim 2 wherein said solid solution is composed of ortho-chloronitrobenzene and ortho-bromonitrobenzene.
Claim 5
Dependent Claim
16 words
A temperature indicator as defined in claim 3 wherein said surface-active agent is a cationic surfactant.
Claim 6
Dependent Claim
18 words
A temperature indicator as defined in claim 4 wherein said cationic surfactant is a fatty acid nitrogen derivative.
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |