Patent ID: 7874820

Claim:
A compressor apparatus ( 20 ) comprising: a housing ( 22 ) having first ( 53 ) and second ( 58 ) ports along a flow path; one or more working elements ( 26 ; 28 ) cooperating with the housing ( 22 ) to define a compression path between suction ( 60 ) and discharge ( 62 ) locations along the flow path; and an unloading valve ( 100 ) having: a valve element ( 102 ) having a portion ( 104 ) along a mesh zone between the working elements and being shiftable via linear translation parallel to axes of rotation of the one or more working elements and having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition; and, means ( 160 ) biasing the valve element toward a third condition intermediate the first and second conditions in displacement volume, the biasing being from both the first condition and the second condition.