Triple action pressure switch apparatus

Abstract

A triple action pressure switch apparatus includes a housing having a pressurized fluid introducing path, the inner space of which is partitioned into a pressure actuating chamber communicated with the path and a switch mechanism storage chamber by a diaphragm. In the latter chamber, a third snap disc assembly, a first piston, a second snap disc assembly, a second piston, a first snap disc assembly, and first and second switches are arranged from the diaphragm in this order in a longitudinal direction of the housing. When the pressure of the pressurized fluid reaches a lower limit of a certain range of value, the first disc is transformed to set the first switch in one of ON and OFF states. When the pressure of the pressurized fluid reaches an upper limit of the range, the second disc is transformed to move a first tubular rod slidably inserted in the second piston and the first disc. Such movement of the first rod set the first switch in the other of ON and OFF states. When the pressure of the pressurized fluid reaches a predetermined value in the range, the third disc is transformed to move a second rod slidably inserted in the first piston, second disc, and the central hole of the first rod. Such movement of the second rod set the second switch in one of ON and OFF states.