Patent attributes
A tandem pump assembly of the type including a housing (H), disposed in which is a first pump (11), driven by an input shaft (19), and a second pump (33), also driven by the input shaft (19). The assembly is characterized by the tandem pump assembly including pressure override valve means (71,73) associated with only the first pump (11), and operable, in response to a fluid pressure at a fluid outlet port (35) in excess of a pressure override setting (79), to communicate pressurized fluid to a first fluid pressure responsive means (31), in a manner tending to decrease the displacement of the first pump (11) without effecting the displacement of the second pump (33), until said fluid pressure is substantially equal to the pressure override selling (79), even if it is necessary for the first pump (11) to go over-center from its initial displacement.