Multiple control valve for mixing fluids

A valve for mixing first and second fluids to produce a mixed flow at a constant temperature at all flow rates, comprising:

• structure defining a mixing chamber;
• first and second inlets for admitting first and second fluids to the mixing chamber;
• an outlet for delivering a mixed fluid flow from the mixing chamber;
• first valve element means in the form of a first piston movable toward and away from a valve seat for controlling the admission of the first fluid through the first inlet into the mixing chamber, the first piston having a portion extending into the mixing chamber;
• second valve element means in the form of a second piston movable toward and away from a valve seat for controlling the admission of the second fluid through the second inlet into the mixing chamber, the second piston having a portion extending into the mixing chamber;
• outlet valve element means for controlling the delivery of mixed fluid through the outlet from the mixing chamber;
• and
• control means for the first, second and outlet valve element means, the control means extending at least partially into the mixing chamber and including cam surfaces engageable with the portions of the first and second pistons extending into the mixing chamber, the control means operating such that during a valve opening opertion the first and second valve element means are fully opened before the outlet valve element means begins to open.