Dual consumer hydraulic mechanisms

Claim 1

In a dual consumer hydraulic mechanism having a source of fluid under pressure, a drive means for said source of fluid, and at least two consumers of hydraulic energy including one primary consumer connected to an receiving fluid under pressure from said source of fluid and in which the maximum fluid consumed by said consumers is greater than the maximum fluid delivery from said source of fluid, the improvement comprising a first multiway valve having two control pressure chambers, one acted upon by fluid pressure from said source to said primary consumer, resilient means acting on said multiway valve normally to reduce the volume of said other chamber, the other of said chambers being connected to pressure signal means at said primary consumer which act in conjunction with said resilient means, a second multiway valve having first and second spring loaded control chambers and a feed chamber connected to the other of said at least two consumers, connection means from said feed chamber to said fluid sorce, selecting means between said first and second multiway valves selectively connecting one of said first and second control chamber of said second multiway valve to a first connection of said first multiway valve, a low pressure source of fluid connected to a second connection on said first multiway valve and through said valve to the first connection, said low pressure source being connected also to the other of said first and second control chambers of said second multiway valve by said selecting means whereby said primary consumer receives the full stream required for its operation as a result of the spring and pressure signal acting on the first multiway valve against the fluid pressure flowing to said primary consumer and at the same time the second multiway valve is acted upon by fluid from the low pressure source through the selecting means simultaneously to reduce flow to the other of said at least two consumers from said fluid source.