Patent Number: 6,296,456

Title: Positive displacement pump systems with a variable control orifice

Abstract: A positive displacement pump system has first and second delivery passages for pumped fluid and a main delivery passage receiving flow from the first delivery passage and, via a non return valve, from the second delivery passage. A control valve is provided to apportion flow from the first and second delivery passage to an overspill port. A pressure sensitive control orifice is provided in the main discharge passage to receive the combined flows and the control orifice is of variable size.

Inventors: Thornelow; Alec (Kent, GB), Brighton; Derek Keith (Kent, GB), Williamson; Matthew (Kent, GB)

Assignee: Dana Automotive Limited

International Classification: F04C 2/344 (20060101); F04C 2/00 (20060101); F04B 049/00 (); F04B 023/00 ()

Expiration Date: 10/02/2018