US4534344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Breathing apparatus and facemasks therefor
Assignee: Siebe Gorman and Co Ltd
•
Filing: 1984-02-08
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Granted: 1985-08-13
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Expires: 2004-02-08
Abstract
Abstract Closed-circuit compressed-oxygen breathing apparatus in which the oxygen supply is used to demist the visor 7 of the facemask 6 or cool the wearer's face before entering an oronasal mask 8 through a one-way valve 13 and mixing with the gas in the breathing circuit.
Inventors
- 👤 Trevor Constance-Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:18
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
187 words
A facemask for breathing apparatus, comprising: an outer mask arranged in use to define with the face of a wearer a volume over the eyes of the wearer that is sealed from the external atmosphere; an inner mask arranged in use to define with the face of the wearer a volume over the mouth and/or nose of the wearer that is sealed both from the interior of the outer mask and from the external atmosphere; first inlet and outlet means to permit a gas to enter the inner mask from the exterior of the facemask and leave the inner mask to the exterior of the facemask; second inlet means to permit a gas to enter the outer mask from the exterior; connectors for gas pipes or tubes provided at the exterior of the facemask, at least one of the connectors being in communication with the first inlet and outlet means and another of the connectors being in communication with the second inlet means; and a one-way valve to permit a gas to flow from the interior of the outer mask to the interior of the inner mask.
Claim 2
Dependent Claim
187 words
A facemask for breathing apparatus, comprising: an outer mask arranged in use to define with the face of a wearer a volume over the eyes of the wearer that is sealed from the external atmosphere; an inner mask arranged in use to define with the face of the wearer a volume over the mouth and/or nose of the wearer that is sealed both from the interior of the outer mask and from the external atmosphere; first inlet and outlet means to permit a gas to enter the inner mask from the exterior of the facemask and leave the inner mask to the exterior of the facemask; second inlet means to permit a gas to enter the outer mask from the exterior; connectors for gas pipes or tubes provided at the exterior of the facemask, at least one of the connectors being in communication with the first inlet and outlet means and another of the connectors being in communication with the second inlet means; and a one-way valve to permit a gas to flow from the interior of the outer mask to the interior of the inner mask.
Claim 3
Dependent Claim
44 words
A facemask as claimed in claim 1, wherein a connector for the first inlet and outlet means is of generally annular form and the connector for the second inlet means is encircled by the said annular connector for the first inlet and outlet means.
Claim 4
Dependent Claim
59 words
A facemask as claimed in claim 2, wherein there are provided at least two of the said connectors for the first inlet and outlet means, and the first inlet and outlet means is arranged in operation to permit a gas to enter the inner mask through the said annular connector and leave the inner mask through another said connector.
Claim 5
Dependent Claim
49 words
A facemask as claimed in claim 1 wherein the outer mask includes a transparent portion through which in use the wearer sees and the second inlet means is arranged in operation to direct a current of gas over the inner surface of that transparent portion of the outer mask.
Claim 6
Dependent Claim
36 words
A facemask as claimed in claim 4, wherein the gas enters the interior of the outer mask from the second inlet means through one or more apertures along the top edge of the said transparent portion.
Claim 7
Dependent Claim
28 words
A facemask as claimed in claim 1, wherein the second inlet means is arranged in operation to direct a current of gas onto the face of the wearer.
Claim 8
Dependent Claim
51 words
Breathing apparatus comprising a facemask as claimed in claim 1, means connected to said inlet and outlet means for purifying gas from the first inlet and outlet means and supplying the purified gas to the first inlet and outlet means, and means adapted to supply oxygen to the second inlet means.
Claim 9
Dependent Claim
106 words
Breathing apparatus as claimed in claim 7, which comprises a backpack unit including means arranged to be worn as a backpack by the wearer and having the purifying means and said means adapted to supply oxygen therein; and flexible pipe means connected between said one connector of the facemask and said purifying means through which in operation exhaled gas flows from the inner mask to the purifying means and purified gas flows to the inner mask from the purifying means and between said another connector and said means adapted to supply oxygen through which in operation oxygen gas flows to the interior of the outer mask.
Claim 10
Dependent Claim
46 words
Breathing apparatus as claimed in claim 8, wherein the facemask is as claimed in claim 2 and said flexible pipe means for supplying oxygen to the second inlet means is within the said flexible pipe means for supplying the purified gas to the first inlet means.
References Cited (Backward Citations)
FR342444A
Cited
US1366392A
Cited
US2168695A
Cited
FR950150A
Cited
US3680556A
Cited
US4404969A
Cited
US4276877A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |