Demand valve for gas mixing
AssigneeConcept 2 Manufacture Design Ocd Ltd
InventorAndrew Tatarek
Life of this patent
Estimating the term…
Abstract
A demand valve for gas mixing comprises two or more flow control valves that are connected to separate gas supplies. The demand valve includes a common actuation mechanism, such as a diaphragm arranged to displace levers, each of which, in turn, opens and closes proportionally in a substantially constant ratio a respective flow control valve. Inhalation flow drawn through an outlet causes displacement of the diaphragm and hence opening of the flow control valves. Gas from the separate supplies is therefore mixed in a main chamber to a substantially constant composition, regardless of the flow rate demanded, before being dispensed via the outlet.
Claims22
A demand valve for gas mixing, the valve comprising at least two gas connection channels, each containing a respective flow control valve, for supplying gas to a main chamber wherein:
- the demand valve includes an actuation means that is responsive to a pressure change in the main chamber;
- each flow control valve is a lever valve that is operated by a respective lever, each lever extending independently of the at least one other lever from a central region of the actuation means to a seal of the respective flow control valve;
- and
- the actuation means is a common actuation means whereby in a single movement it is operable to move the respective levers such that they each displace the seal from a seat of its respective flow control valve so as to open and close proportionally in a substantially constant ratio the at least two flow control valves.
A method of mixing gases on demand, the method comprising the steps of:
- (a) changing pressure in a main chamber of a demand valve in response to a user's respiration;
- and
- (b) moving a common actuation means in response to the pressure variation at step (a), the common actuation means being operable to displace at least two levers, each lever extending, independently from the at least one other lever, from the actuation means to respective flow control valves such that the flow control valves open and close proportionally in a substantially constant ratio, the at least two flow control valves being pre-positioned in respective gas connection channels taking gas from respective independent sources.
A demand valve for gas mixing, the valve comprising at least two gas connection channels, each containing a respective flow control valve, for supplying gas to a main chamber wherein:
- the demand valve includes an actuation means that is responsive to a pressure change in the main chamber;
- each flow control valve is a lever valve that is operated by a respective lever, each lever extending independently of the at least one other lever from a central region of the actuation means to a cap comprising a sealing face for sealing against the seat of the respective flow control valve;
- a protrusion is located in a bore of each gas connection channel so as to interengage with the cap and inhibit rotational movement of the cap and connected lever;
- and
- the actuation means is a common actuation means whereby in a single movement it is operable to move the respective levers such that they each displace the seal from a seat of its respective flow control valve so as to open and close proportionally in a substantially constant ratio the at least two flow control valves.
Dependencies are inferred from the claim text.