Patent ID: 6290139
Filing Date: 2001-09-18
Classification: G05D

Abstract:
A hydraulically actuated mixing valve for operation within a system for controlling the flow and temperature of hot and cold fluids comprising:a) a housing having a main chamber comprising:i. hot and cold fluid inlets for receiving hot and cold supply fluids and an outlet for discharging mixed hot and cold fluids;ii. a hydraulically movable member disposed within said main chamber, said hydraulically movable member having a high pressure side and a low pressure side, said hydraulically movable member being responsive to fluid pressure differentials;iii. a mixing chamber formed within said main chamber to mix said hot and cold supply fluids for discharge to said outlet;iv. internal mixing means associated with said mix chamber, said internal mixing means responsive to movement of said hydraulically movable member;v. pressure differential means within said housing and in a flow path relationship with said inlet, said mix means, and said outlet for providing sufficient pressure differential across said hydraulically movable member to actuate the movable member and consequently move said mixing means, said pressure differential means being a separate member from said mixing means;vi. at least two control passageways, one connecting said high pressure side of said hydraulically movable member to an upstream side of said pressure differential means and the other connecting said low pressure side of said hydraulically movable member to a downstream side of said pressure differential means; and,vii. a control valve associated with at least one of said control passageways to control fluid flow in said control passageway thereby actuating movement of said hydraulically movable member and said internal mix means to change the proportions of hot and cold fluids for mixture temperature control.