Patent attributes
A compressor may include a housing and first and second scroll members supported within the housing, each having an end plate with a spiral wrap extending therefrom and meshingly engaged with the other to form a series of compression pockets operating at an intermediate fluid pressure between a suction pressure and a discharge pressure. A first passage in communication with one of the compression pockets extends from a first side of the first end plate to a second side of the first end plate generally opposite the first side. A modulation plate overlies the second side of the first scroll member for radial displacement between first and second positions. The modulation plate isolates the first passage from communication with a suction pressure region of the compressor when in the first position and provides communication between the first passage and the suction pressure region when in the second position.