Variable displacement fluid device

Claim 1

A SWASH PLATE TYPE VARIABLE DISPLACEMENT FLUID DEVICE, COMPRISING, A HOUSING HAVING AN ARCUATE PORT SEGMENT DEFINED THEREIN, A PORT PLATE HAVING BEARING SURFACE MEANS SEATED AGAINST SAID PORT SEGMENT FOR ARCUATE SLIDING MOVEMENT ABOUT AN AXIS, A CYLINDER BARREL HAVING CYLINDER MEANS FORMED THEREIN AND SEATED FOR ROTATION IN BEARING RELATIONSHIP AGAINST SAID PORT PLATE, SWASH MEANS ROTATABLE IN SAID HOUSING, PISTON MEANS SLIDABLE IN SAID CYLINDER MEANS AND CONNECTED TO SAID SWASH MEANS, THE DEVELOPMENT OF FLUID PRESSURE IN SAID CYLINDER MEANS DURING NORMAL OPERATION OF THE DEVICE PRODUCING A PREDETERMINED FIRST EFFECTIVE FORCE TENDING TO URGE SAID CYLINDER BARREL AND SAID PORT PLATE TOWARD SAID PORT SEGMENT, SAID BEARING SURFACE MEANS ON SAID PORT PLATE COMPRISING BEARING LAND MEANS OF PREDETERMINED RELATIVELY SMALL SURFACE AREA PRECALCULATED TO PRODUCE A PREDETERMINED SECOND EFFECTIVE FORCE OF SLIGHTLY LESS MAGNITUDE THAN SAID FIRST PREDETERMINED EFFECTIVE FORCE TENDING TO URGE SAID PORT PLATE AWAY FROM SAID PORT SEGMENT WHEN SUBJECTED TO LEAKAGE FLUID UNDER PRESSURE DURING NORMAL OPERATION OF SAID DEVICE, WHEREBY SAID PORT PLATE IS URGED IN A CRITICAL PRESSURE BALANCE LIGHTLY TOWARD SAID PORT SEGMENT DURING SAID NORMAL OPERATION.