Patent ID: 6799952
Filing Date: 2004-10-05
Classification: F04B,Y10T

Abstract:
A pneumatic control valve that selectively opens and closes a passage between compressor discharge and crankcase ports for purposes of controlling a compressor capacity, comprising:a stopper biased against a seat in said passage, and having an axial bore; a plunger having an axial bore that is aligned with the axial bore of said stopper, a first end that is maintained in engagement with said stopper so as to seal a compressor discharge fluid in the axial bores of said stopper and plunger, and a second end that is slidably disposed in a control valve cavity; an annular bellows responsive to a compressor suction pressure and disposed radially about said plunger to effect axial displacement of said plunger and stopper for opening and closing said passage in response to said suction pressure; and a pressure sensor for sensing a pressure in said control valve cavity for producing a signal indicative of a pressure in said discharge port.