EP0094757A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Respirator
Assignee: Racal Safety Ltd
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Filing: 1983-05-03
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Granted: —
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Expires: 2003-05-03
Abstract
Abstract The present invention relates to improvements in power assisted positive pressure respirators for use in contaminated atmospheres. The respirator comprises a facepiece 1 having an inlet 3 connected to a pump unit 5 for supplying air to the facepiece which has been filtered by filter means 11 connected to the pump unit inlet. The facepiece is also provided with an outlet provided with a one-way valve 2 which is biased to its closed position and is openable when a predetermined pressure above atmospheric pressure is established within the facepiece. To maximise use of the filter means 11, a one-way inlet valve 13 is provided intermediate the pump unit 5 and the facepiece 1, conveniently at the inlet to the facepiece, which is closed during exhalation by the wearer to thereby cause the pump to be placed in a condition in which, although it continues to operate, no or substantially no air is moved thereby, so that during this period, no or substantially no air is drawn through the filter means 11.
Inventors
- 👤 Raymond Odell
- 👤 Richard Kevin O'connor
- 👤 David Brian Edward
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 07:21
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/006
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
163 words
A power assisted respirator comprising a facepiece 1 for covering at least the mouth of the wearer and having an inlet 3 and an outlet, first one-way valve means 2 in the outlet which is openable during exhalation by the wearer to permit air to flow out of the facepiece when a predetermined differential pressure is established thereacross, pump means 5 connected to the inlet 3 for supplying air to the facepiece, and filter means 11 for filtering air supplied by the pump means to the facepiece, characterised in that second one-way valve means 13 is provided in the path of air flowing from the pump means to the facepiece, which valve means 13 is arranged to be closed during exhalation by the wearer when the pressure downstream thereof exceeds that upstream thereof and so that the pump means will thereby be placed in a condition such that, although the pump means continues to operate, little or substantially no air is driven thereby.
Claim 2
Dependent Claim
163 words
A power assisted respirator comprising a facepiece 1 for covering at least the mouth of the wearer and having an inlet 3 and an outlet, first one-way valve means 2 in the outlet which is openable during exhalation by the wearer to permit air to flow out of the facepiece when a predetermined differential pressure is established thereacross, pump means 5 connected to the inlet 3 for supplying air to the facepiece, and filter means 11 for filtering air supplied by the pump means to the facepiece, characterised in that second one-way valve means 13 is provided in the path of air flowing from the pump means to the facepiece, which valve means 13 is arranged to be closed during exhalation by the wearer when the pressure downstream thereof exceeds that upstream thereof and so that the pump means will thereby be placed in a condition such that, although the pump means continues to operate, little or substantially no air is driven thereby.
Claim 3
Dependent Claim
25 words
A respirator as claimed in claim 1, characterised in that the second one-way valve means 13 is mounted in the inlet 3 of the facepiece.
Claim 4
Dependent Claim
33 words
A respirator as claimed in claim 1, characterised in that the second one-way valve means 13 is mounted intermediate the outlet of the pump means 5 and the inlet 3 of the facepiece.
Claim 5
Dependent Claim
42 words
A respirator as claimed in any one of the preceding claims, characterised in that the second one-way valve means 13 comprises a flap valve which is unbiased so as to close as soon as the pressure downstream thereof exceeds that upstream thereof.
Claim 6
Dependent Claim
31 words
A respirator as claimed in any one of the preceding claims, characterised in that the first one-way valve means 2 is a flap valve which is biased to its closed position.
Claim 7
Dependent Claim
37 words
A respirator as claimed in any one of the preceding claims, characterised in that the pump means 5 is connected to the facepiece by a flexible hose 4 and is adapted to be carried by the wearer.
Claim 8
Dependent Claim
23 words
A respirator as claimed in any one of the preceding claims, wherein the facepiece 1 covers the mouth and nose of the wearer.
Claim 9
Dependent Claim
24 words
A respirator as claimed in any one of the preceding claims, wherein the facepiece 1 covers the mouth, nose and eyes of the wearer.
Claim 10
Independent Claim
146 words
A method of operating a power assisted respirator comprising a facepiece 1 for covering at least the mouth of the wearer and having an inlet 3 and an outlet, first one-way valve means 2 in the outlet which is openable to permit air to flow out of the facepiece, pump means 5 connected to the inlet 3 for supplying air to the facepiece 1, and filter means 11 for filtering air supplied by the pump means 5 to the facepiece, the method comprising providing a second one-way valve means 13 in the path of air flowing from the pump means 5 to the facepiece and causing the second one-way valve means 13 to be closed during exhalation by the wearer so as to place the pump means 5 in a condition such that, although it continues to operate, little or substantially no air is driven thereby.
Claim 11
Independent Claim
146 words
A method of operating a power assisted respirator comprising a facepiece 1 for covering at least the mouth of the wearer and having an inlet 3 and an outlet, first one-way valve means 2 in the outlet which is openable to permit air to flow out of the facepiece, pump means 5 connected to the inlet 3 for supplying air to the facepiece 1, and filter means 11 for filtering air supplied by the pump means 5 to the facepiece, the method comprising providing a second one-way valve means 13 in the path of air flowing from the pump means 5 to the facepiece and causing the second one-way valve means 13 to be closed during exhalation by the wearer so as to place the pump means 5 in a condition such that, although it continues to operate, little or substantially no air is driven thereby.
References Cited (Backward Citations)
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