Pressure pilot switch point device

Claim 1

In a fluid pressure sensor for monitoring a process pressure, including a Bourdon tube having an input end coupled to the process pressure and a moving output end responding to the process pressure to move in a first direction upon sensing an increasing pressure and in a second direction upon sensing a decreasing pressure, and switch point setting means for adjustably setting a pressure set point and adapted for engagement by the Bourdon tube moving output end when the pressure set point is reached, improved switch point setting means for maintaining a reliable pressure set point, said switch point setting means comprising: a cylindrical housing; an elongated threaded shaft rotatably mounted in said housing; a movable post member including a base portion sized to substantially conform to the inner surface of said housing, said base portion threadably mounted on said elongated threaded shaft for longitudinal movement along said shaft during rotation thereof during setting of said pressure set point, and a post portion extending from the base portion and projecting from the housing for engagement by the Bourdon tube moving output end; spring means within the housing for biasingly urging the base portion in positive threadable engagement with said shaft; and resilient means captured between said base portion and said housing inner surface for movement with said base portion; said resilient means in resilient engaging contact with said housing inner surface to prevent undesired movement of said base portion with respect to said housing while enabling the base portion to be threadably moved by rotating said threaded shaft during setting of the desired pressure set point to overcome said resilient engaging contact of said resilient means with said housing inner surface.