Patent US3811422A successfully refreshed from Google Patents.
US3811422A
Expired / Lapsed
US
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Chemical heater tube
Assignee: United States Department of the Navy
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Filing: 1972-10-05
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Granted: 1974-05-21
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Expires: 1992-10-05
Abstract
Abstract A chemical heater-cartridge for producing high amounts of heat without excessive pressure rises. A sealed, thin-walled, steel tube filled with solid lithium surrounding a core of Teflon powder forms the portable heater-cartridge. The exothermic reaction of this mixture, initiated by a pyrotechnic fuze, results in a high heat output and a reduction of pressure within the cartridge. This reduction of pressure permits the use of a small-mass tube which increases the rate of heat transfer. Sulfur hexafluoride vapor (SF6) or Freon may be added under pressure to enhance the reaction rate. Alkali metals, other than lithium, and fluorocarbons, other than Teflon, may be used and are equivalent reactants.
Inventors
- 👤 D Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:20
CPC Classifications
C; C09; C09K; C09K5/00; C09K5/16; F; F24; F24V; F24V30/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
21 words
The portable heater tube of claim 1 wherein the lithium is present in excess amounts in proportion to a stoichiometric mixture.
Claim 2
Dependent Claim
29 words
The portable heater tube of claim 1, wherein the lithium substantially fills the container with the exception of a central core, said core being substantially filled with said tetrafluoroethylene.
Claim 3
Dependent Claim
23 words
The portable heater tube of claim 1 wherein the third constituent is sulfur hexafluoride at a charging pressure of at least 100 psig.
Claim 4
Dependent Claim
23 words
The portable heater tube of claim 1 wherein the third constituent is Freon gas at a charging pressure of at least 100 psig.
Claim 5
Dependent Claim
29 words
The portable heater tube of claim 5 wherein the lithium substantially fills the container with the exception of a central core, said core being substantially filled with said tetrafluoroethylene.
Claim 6
Dependent Claim
60 words
A portable heater tube comprising: a hermetically sealed container; a reactant charge disposed within said container; said reactant charge being composed of lithium and tetrafluoroethylene, wherein the lithium fills the container with the exception of a central core, said core being filled with said tetrafluoroethylene; and means connected to said container to initiate a chemical reaction in said reactant charge.
Claim 7
Dependent Claim
21 words
The portable heater tube of claim 7 wherein the lithium is present in excess amounts in proportion to a stoichiometric mixture.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |