Valve with a reduced number of exhaust ports and vents

摘要

A pilot valve is provided with internal conduits that eliminate the need for all but one exhaust or vent opening in the outer surface of the valve. The pilot vent is directed through a gap between inner and outer tubes so that the fluid flowing through the upper end of the pilot cavity can be directed to the single exhaust port of the valve. The piston cavity vent is similarly connected to the exhaust port through the use of a counterbore cavity formed between a portion of the cavity in which the driving end of the spool member is disposed and a conduit connecting the counterbore cavity to the exhaust port of the valve. In addition, a second exhaust port, if needed for the valve application, is provided completely internal to the surfaces of the valve body and connected via a conduit to the first exhaust port which extends through an outer surface of the valve body. Through the use of these various techniques, the present invention eliminates most vents and ports and reduces the necessary number of the openings in the outer surface of the valve body to a single exhaust port which can be appropriately connected to a means for exhausting the fluid into the environment based on the particular application in which the valve is used.