Breathing apparatus
First Claim
1. A forced air breathing apparatus comprising a face piece or mask covering at least the nose or mouth of a wearer, a pump unit arranged to supply air to a space within the face piece or mask, an electric motor within the pump unit arranged to drive a fan forming part of the pump unit, a filter to filter air entering the face piece or mask and a valve means controlling the flow of air from the pump unit to the face piece or mask during inhalation and from the face piece or mask during exhalation, the valve means including an air inlet valve and an air outlet valve, the air outlet valve being maintained in a closed position during inhalation through the air inlet valve by air pressure from the pump unit and being opened by exhaled air which also acts on the inlet valve to prevent the entry of exhaled air to the pump unit.
3 Assignments
0 Petitions
Accused Products
Abstract
A forced air breathing apparatus which includes a face piece (20a) for covering at least the nose or mouth of a wearer, a pump unit (10) arranged to supply air to a space within the face piece (20a), a filter (13) to filter air entering the face piece (20a) and valve means to control the flow of air from the pump unit (20) to the face piece (20a) during inhalation and from the face piece (20a) during exhalation. The pump unit (20) includes a fan (12) driven by an electric motor (11). The valve means includes an air inlet valve (19) and an air outlet valve (22), the air outlet valve (22) being maintained in a closed position during inhalation through the air inlet valve (19) by air pressure from the pump unit (20) and being opened by exhaled air. The exhaled air also acts to close the air inlet valve (19) and prevents the entry of exhaled air to the pump unit (20). The fan (12) is a centrifugal fan driven at a substantially constant speed. A valve (14) is provided on the air inlet side of the pump unit (10) and is arranged to close when a defined air pressure is present within the pump unit (10) downstream of the fan (12).
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Citations
26 Claims
- 1. A forced air breathing apparatus comprising a face piece or mask covering at least the nose or mouth of a wearer, a pump unit arranged to supply air to a space within the face piece or mask, an electric motor within the pump unit arranged to drive a fan forming part of the pump unit, a filter to filter air entering the face piece or mask and a valve means controlling the flow of air from the pump unit to the face piece or mask during inhalation and from the face piece or mask during exhalation, the valve means including an air inlet valve and an air outlet valve, the air outlet valve being maintained in a closed position during inhalation through the air inlet valve by air pressure from the pump unit and being opened by exhaled air which also acts on the inlet valve to prevent the entry of exhaled air to the pump unit.
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23. A positive air pressure respirator apparatus comprising a face piece or mask covering at least the mouth or nose of a wearer, a pump unit arranged to supply air to the space within the face piece or mask, an electric motor within the pump unit arranged to drive a fan, wherein the apparatus is provided with actuable control means adapted to cause the apparatus to undergo a calibration phase such that the speed of rotation of the fan is set at a pre-determined optimum base value relative to the operating conditions then prevailing in the apparatus.
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24. A positive air pressure respirator apparatus comprising a plurality of parts including a face piece or mask covering at least the mouth or nose of a wearer, a pump unit arranged to supply air to the space within the face piece or mask, an electric motor within the pump unit arranged to drive a fan, at least one filter to filter air entering the face piece or mask, a valve controlling the flow of air from the pump unit to the face piece or mask during inhalation and from the face piece or mask during exhalation, the valve including an air outlet valve which is maintained in a closed position during inhalation by air pressure from the pump unit, and a performance monitoring means for some or all of the parts which provides at least one signal that informs the wearer of the condition of some or all of the parts, wherein the signal is generated externally to the face piece or mask and is fed to the face piece or mask for detection by a wearer.
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25. A forced air breathing apparatus comprising a face piece or mask for covering at least the nose or mouth of a wearer, a pump unit arranged to supply air to a space within the face piece or mask, an electric motor within the pump unit arranged to drive a centrifugal fan, means for monitoring and controlling the speed of the motor so that the fan rotates at a substantially constant speed during its operation, a filter to filter air entering the face piece or mask and a valve controlling exhalation of air from the face piece or mask by a user.
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26. A forced air breathing apparatus comprising a face piece or mask for covering at least the nose or mouth of a wearer, a pump unit arranged to supply air to a space within the face piece or masks, an electric motor within the pump unit arranged to drive a fan forming part of the pump unit, and a first valve controlling exhalation of air from the face piece or mask by a user, the apparatus including a second valve controlling the flow of air through the pump unit, the second valve being arranged to close when the pressure present within the breathing apparatus downstream of the fan rises to a predetermined level.
Specification