Patent ID: 6877523

Claim:
A valve assembly for mixing hot and cold water including: a generally cylindrical sleeve having axially spaced hot and cold water inlets in the side thereof, axially spaced hot and cold outlets in said sleeve located peripherally of said inlets, said sleeve hot water outlet being larger than sleeve cold water outlet; a rotatable non-reciprocal valve member positioned within said sleeve to control the mixture of hot and cold water, said valve member including a hollow stem tube having hot and cold water inlet and outlet ports therein and a seal-less reciprocally movable pressure balancing spool positioned within said stem tube, said spool and stem tube providing two spaced chambers, said stem tube cold water inlet and outlets ports opening into one chamber and said stem tube hot water inlet and outlet ports opening into the other chamber, with a portion of said chamber walls forming balancing surfaces such that said spool provides for balancing of pressures between the hot and cold water inlet ports, wherein fluid engagement between said sleeve hot and cold water outlets and said stem tube hot and cold water outlet ports providing a full hot water flow range, a full cold water flow range and a mixed hot and cold water flow range, the mixed hot and cold water flow range being greater than selected one of the full hot water and full cold water flow ranges; and a valve seal positioned on said sleeve at each of said sleeve hot and cold water inlets and extending therethrough for sealing contact with said valve member.