Patent ID: 6382248
Filing Date: 2002-05-07
Classification: F16H,G05D,Y10T

Abstract:
A self-diagnosing pressure regulator apparatus for supplying a regulated fluid pressure to a hydraulic element in relation to a trim pressure, comprising:a pressure regulating valve spool axially positionable within a valve bore, the valve spool having first and second opposed pressure control areas and spaced lands defining first and second fluid chambers between said lands, said hydraulic element being continuously coupled to said first fluid chamber; a pressure-responsive diagnostic switch being continuously coupled to said second fluid chamber; first and second fluid pressure passages and first and second exhaust passages selectively coupled to said first and second fluid chambers, respectively, depending on the position of said valve spool within said valve bore, said first and second fluid pressure passages containing first and second fluid pressures, and said exhaust passages containing an exhaust pressure; and a trim passage for directing said trim pressure to the first pressure control area, and a spring and hydraulic element feedback pressure acting on the second pressure control area, whereby said valve spool is positioned within said valve bore in response to said trim pressure, said spring and said feedback pressure to establish one of: (1) an OFF state in which fluid in said first and second fluid chambers is exhausted through said first and second exhaust passages and said diagnostic switch detects a deactivated state of said valve spool in response to said exhaust pressure, (2) a TRIM state in which fluid in said first chamber is regulated in relation to said trim pressure, said second chamber is continuously coupled to said second fluid pressure passage, and said diagnostic switch detects an activated state of said valve spool in response to said second fluid pressure and (3) an ON state in which said first chamber is continuously coupled to said first fluid pressure passage, said second chamber is continuously coupled to said second fluid pressure passage, and said diagnostic switch detects an activated state of said valve spool in response to said second fluid pressure.