US 2010/0147306 A1 · BREATHING APPARATUS

Abstract

A face mask (10) mechanically coupled to a lung demand valve (LDV) (12). The face mask (10) comprises a main mask and an inner mask (15) which fits over the wearer's mouth and nose. The interior of the inner mask (15) is in fluidic communication with the interior of the main mask (10) by means of non-return valves (16). The interior of the main mask is in fluidic communication with an inlet port (18) which is mechanically and fluidically coupled to a supply port (20) of an LDV. The LDV (12) includes a diaphragm and a cover (44) which comprises three parts (44a, 44b) and (44c). Exhaled air is used to flush the space around the diaphragm. Thus, any toxic or undesirable gas in the vicinity of the diaphragm is pushed out to atmosphere by the exhaled air flowing past and around the diaphragm.

Claims14

Dependent claims

A lung demand valve device for use with breathing apparatus, for delivering breathable gas from a pressurized supply to a user wearing a face mask, for inhalation, the device comprising a body in which is housed a valve member, for controlling the rate of delivery of the breathable gas, a movable diaphragm having a first face exposed to pressure within the body and a second face exposed to pressure outside the body, the diaphragm being responsive to the differential in pressure between its first and second faces to control the valve member, and a duct arranged to direct exhaled air towards said second face of said diaphragm.

A self-contained breathing apparatus in which fluid for breathing is conveyed to a user on inhalation, the apparatus comprising:

a face mask connected to a lung demand valve and worn by a user, said face mask including an inner mask for surrounding the nose and mouth of the user and receiving fluid inhaled and exhaled by the user;
a body housing said lung demand valve;
a high pressure cylinder containing the fluid for breathing;
a hose for conveying fluid from the cylinder to the lung demand valve, said lung demand valve comprising:
a valving member for receiving the fluid conveyed through the hose under pressure, said valving member including an actuator arm for controlling fluid flow through the valving member;
a first fluid path for conveying fluid for inhalation from the valving member to the inner mask;
a second fluid path for conveying exhaled fluid through the inner mask to the atmosphere and being vented to atmosphere;
a flexible diaphragm having first and second faces, said first face being exposed to pressure within the body and the second face being exposed to pressure outside the body, the diaphragm being responsive to the differential in pressure between said first and second faces to control the valving member through operation of said actuator arm;
a cover member extending around the body for preventing the ingress of dirt into the body, said cover member comprising a plurality of portions detachably fixed together, one of said portions constituting a rigid duct portion constituting a part of the second fluid path for receiving the exhaled air;
said second fluid path being in communication with the second face of the flexible diaphragm, whereby exhaled fluid passes over the second face for pushing any toxic or other undesirable gas in the vicinity of the second face to atmosphere;
another portion of said cover member including spaced-apart, upstanding lugs contiguous to a pair of lugs on said face mask for preventing rotation of the cover member and body relative to the face mask.

8 more elements

Dependencies are inferred from the claim text.

Breathing apparatus

Life of this patent

Breathing apparatus

Life of this patent

Abstract

Claims14