Patent ID: 8443826
Filing Date: 2013-05-21
Classification: A61M,A62B,F16K,Y10T

Abstract:
1. 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.