US3618558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unsafe condition indicator for frozen food chests
Assignee: Individual
•
Filing: 1970-05-01
•
Granted: 1971-11-09
•
Expires: 1990-05-01
Abstract
Abstract A card having mounted thereon a transparent waterproof tube containing a liquid solution and a short indicator rod. The card is placed in a freezing unit until the liquid, with the rod within it, freezes. The card is then inverted in the freezer unit. When the temperature of the unit rises above the melting point of the liquid, the indicator rod will fall indicating an unsafe condition.
Inventors
- 👤 Barry Tepfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:26
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06; G01K11/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
126 words
An indicator for detecting the occurrence of a temperature rise above a preset maximum in a cold storage unit, said indicator comprising the combination of: a. a card; b. an elongated transparent tube having both ends thereof sealed; said tube being secured to said card; c. a solidifiable liquid having a melting point within a few degrees of said preset maximum temperature, said liquid almost filling said tube; d. a transparent solution in said liquid for reducing surface tension; e. a rod within said tube, said rod having a density greater than said liquid and said transparent solution, said rod being arranged for free longitudinal motion within said tube; and f. hook means attached to said card for mounting said tube longitudinally in either inverse direction.
Claim 2
Dependent Claim
126 words
An indicator for detecting the occurrence of a temperature rise above a preset maximum in a cold storage unit, said indicator comprising the combination of: a. a card; b. an elongated transparent tube having both ends thereof sealed; said tube being secured to said card; c. a solidifiable liquid having a melting point within a few degrees of said preset maximum temperature, said liquid almost filling said tube; d. a transparent solution in said liquid for reducing surface tension; e. a rod within said tube, said rod having a density greater than said liquid and said transparent solution, said rod being arranged for free longitudinal motion within said tube; and f. hook means attached to said card for mounting said tube longitudinally in either inverse direction.
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) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |