A breathing apparatus includes a source of compressed air and a lung demand valve that receives compressed air from the source. A pneumatic valve assembly is connected between the source and the lung demand valve. The pneumatic valve assembly is moveable between a first closed position that prevents a flow of compressed air to the lung demand valve and a second open position that provides a path for compressed air to flow to the lung demand valve. A mask receives the lung demand valve therein. The mask provides the compressed air to a user and having a first operational mode providing filtered ambient air to the user and a second operational mode providing compressed air to the user. A control device is coupled to the pneumatic valve assembly. The control device detects a condition in the air surrounding the apparatus and controlling the pneumatic valve assembly to move between the first closed and second open position and the mask to operate in a respective one of the first and second operational modes.

Diving equipment includes a compressed air bottle connected to a breathing apparatus and an inflatable jacket via which buoyancy is balanced by the jacket being connected to the compressed air bottle to be inflated or to an outlet to be deflated. A monitoring device is activated via a control valve as a function of surrounding water pressure and has a time monitoring unit which, after the expiry of a defined time and in the absence of breathing activity in the breathing apparatus, changes to emergency operation and activates an emergency valve via a control line connecting the jacket to the compressed air bottle to force inflation of the jacket. Actuation of at least one regulating valve is influenced during a dive by the monitoring device and/or the control valve. In manual activation, the jacket is inflated via the inflation valve, and the compressed air is bled via the outlet valve.

An attachable, detachable pressure reducing regulator for use with a primary high-pressure gas source, wherein the high-pressure chamber of said regulator includes a secondary gas IN portal, with a one-way valve, through which the primary container source may be refilled from an external gas source, via the high-pressure chamber of the said regulator, either independently of or concurrently during its use as a pressure reducing regulator.

Systems and methods for emergency breathing systems in accordance with embodiments of the invention are disclosed. In an embodiment, a second stage regulator includes a housing, a first nosepiece coupled to a first lever, a second nosepiece coupled to a second lever, a first spring located in the housing and coupled to the first nosepiece and the first lever, a second spring located in the housing and coupled to the second nosepiece and the second lever, a mouthpiece, and a coupler coupled to the housing, wherein the first spring and the second spring bias the first nosepiece and the second nosepiece towards each other.

A vent valve apparatus (10) for use with a system for supplying breathable gas pressurised above atmospheric pressure to a human or animal. The apparatus (10) includes a gas washout vent (15), a vent valve (18) adapted to progressively restrict the flow area of the washout vent (15), and a pressure sensitive vent valve control means (20,22,23). The control means is adapted to progressively cause the vent valve (18) to restrict the flow area of the gas washout vent (15) in response to increases in the pressure of the gas supply, thereby substantially regulating the volumetric flow of gas and/or CO.sub.2 gas through the washout vent (15) over a range of gas supply pressures.

A method for determining a characteristic such as partial pressure or percentage of a gaseous constituent in a first gas mixture flow in a flow chamber in which there is alternating flow in opposite directions between the first gas mixture flow and a second gas mixture flow. The steps may include a) introducing the first gas mixture flow into a sensing chamber when the first gas mixture flow flows in the flow chamber, b) preventing introduction of gas from the flow chamber into the sensing chamber at least when the second gas mixture flow flows in the flow chamber, c) sensing the characteristic of the first gas mixture flow in the sensing chamber.

A respiratory system composes an oxygen supply, a vented respiratory mask, a hose coupled to the oxygen supply, and a connector apparatus joining the respiratory mask and the hose. The connector apparatus may comprise mask connector member to govern fluid flow through a vent in a mask, a mask valve received in a mask fluid flow passage movable between a rest position in which the mask fluid flow passage is blocked and an actuated position in which the mask fluid flow passage is unblocked, a biasing member biasing the mask valve towards the rest position, and a hose connector member to be secured to a fluid hose. The hose connector member includes a valve actuator to move the mask valve to the actuated position when the hose connector member is coupled to the mask connector member.

A respiratory system composes an oxygen supply, a vented respiratory mask, a hose coupled to the oxygen supply, and a connector apparatus joining the respiratory mask and the hose. The connector apparatus may comprise mask connector member to govern fluid flow through a vent in a mask, a mask valve received in a mask fluid flow passage movable between a rest position in which the mask fluid flow passage is blocked and an actuated position in which the mask fluid flow passage is unblocked, a biasing member biasing the mask valve towards the rest position, and a hose connector member to be secured to a fluid hose. The hose connector member includes a valve actuator to move the mask valve to the actuated position when the hose connector member is coupled to the mask connector member.

A mask apparatus includes a mask body and a mask body cover coupled to the mask body. The mask body includes a front surface, a rear surface, and a pair of air ducts disposed at left and right sides of the front surface. The mask body is configured to mount a pair of fan modules at suction sides of the pair of air ducts. The mask body cover covers the pair of air ducts and the pair of fan modules. The mask body defines a cover coupling groove along an edge of the mask body, and the cover coupling groove is coupled to an edge of the mask body cover.

A mask apparatus includes a mask body and a mask body cover coupled to the mask body. The mask body includes a front surface, a rear surface, and a pair of air ducts disposed at left and right sides of the front surface. The mask body is configured to mount a pair of fan modules at suction sides of the pair of air ducts. The mask body cover covers the pair of air ducts and the pair of fan modules. The mask body defines a cover coupling groove along an edge of the mask body, and the cover coupling groove is coupled to an edge of the mask body cover.