Patent US3742683A successfully refreshed from Google Patents.
US3742683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxygen producing unit with cooled casing
Assignee: MSA Safety Inc
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Filing: 1971-05-03
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Granted: 1973-07-03
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Expires: 1991-05-03
Abstract
Abstract An oxygen producing candle is surrounded by a metal shell, which in turn is enclosed in a metal casing spaced from the shell. The unit is provided with an oxygen passage connecting the inside of the shell with the outside of the unit for delivery of oxygen therefrom. The space between the shell and casing is filled with a hydrated compound which will be dissociated by the heat from the burning candle and give off water vapor to limit the temperature of the casing to a safe level.
Inventors
- 👤 A Sebest
- 👤 F Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:30
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/04; B; B01; B01J; B01J7/00; C; C01; C01B; C01B13/00; C01B13/02; C01B13/0296
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
125 words
An oxygen unit comprising an oxygen producing candle, means at one end of the candle for igniting it, a metal shell surrounding the candle, a metal casing surrounding the shell, means spacing the casing from the shell to form a closed chamber between them, said igniting means extending through said casing, said unit being provided with an oxygen passage connecting the inside of the shell with the outside of the casing, and a hydrated compound filling the chamber between the shell and casing, which compound will be dissociated by the heat from the burning candle and will give off water vapor to hold down the temperature of the surrounding casing, and said chamber being provided with an outlet for said vapor directly to the atmosphere.
Claim 2
Dependent Claim
125 words
An oxygen unit comprising an oxygen producing candle, means at one end of the candle for igniting it, a metal shell surrounding the candle, a metal casing surrounding the shell, means spacing the casing from the shell to form a closed chamber between them, said igniting means extending through said casing, said unit being provided with an oxygen passage connecting the inside of the shell with the outside of the casing, and a hydrated compound filling the chamber between the shell and casing, which compound will be dissociated by the heat from the burning candle and will give off water vapor to hold down the temperature of the surrounding casing, and said chamber being provided with an outlet for said vapor directly to the atmosphere.
Claim 3
Dependent Claim
22 words
An oxygen unit according to claim 1, including a steam pressure relief valve secured to said casing and forming said chamber outlet.
Claim 4
Dependent Claim
29 words
An oxygen unit according to claim 1, including a relief valve connecting the space between said shell and casing with said oxygen passage to humidify oxygen in said passage.
Claim 5
Dependent Claim
18 words
An oxygen unit according to claim 1, including means in said passage for filtering and for removing chlorine.
Claim 6
Dependent Claim
82 words
An oxygen unit according to claim 4, in which said shell is spaced from the candle, a portion of said oxygen passage is inside the shell and encircles the candle, and said filtering and chlorine removing means are annular members encircling the candle, said members including in order a screen, a bed of heat-resistant fibers, a bed of soda lime, a molecular sieve, a bed of heat-resistant fibers, a bed of hopcalite, a screen, a bed of heat-resistant fibers, and a screen.
Claim 7
Dependent Claim
63 words
An oxygen unit according to claim 4, in which said shell is spaced from the candle, and a portion of said oxygen passage is inside the shell between it and a sleeve enclosing a portion of the candle, and said filtering and chlorine removing means are annular members encircling the candle and disposed in some of the space between the shell and sleeve.
Claim 8
Dependent Claim
32 words
An oxygen unit according to claim 6, in which said sleeve is spaced from the candle, and said unit includes insulation filling the space between the candle and the sleeve and shell.
Claim 9
Dependent Claim
96 words
An oxygen unit according to claim 1, in which said shell is spaced from the candle and including a sleeve inside the shell and surrounding the end of the candle opposite to its ignition end, the sleeve being closed at its outer end and spaced inwardly from the shell to form an oxygen chamber between them communicating with the space between the shell and candle, and filtering and chlorine removing means in the path of oxygen entering said chamber from between the candle and shell, said chamber having an outlet forming part of said oxygen passage.
Claim 10
Dependent Claim
41 words
An oxygen unit according to claim 8, in which said filtering and chlorine removing means are spaced from the outer end of the sleeve, and said chamber outlet is located between the outer end of the sleeve and said filtering means.
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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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |