Abstract: A pressure switch includes a housing, the inner space of which is divided into a pressurized fluid operating chamber and a switch mechanism chamber by a flexible diaphragm. The operating chamber communicates with a pressurized fluid inlet hole, and the mechanism chamber houses a switch mechanism. The diaphragm is hermetically fixed to the inner surface of the housing by an elastic seal member. The switch mechanism has a spring for urging the diaphragm toward the operating chamber. The switch mechanism is turned on or off as the diaphragm is transformed against the urging force of the spring by the pressure of a fluid introduced through the inlet hole into the operating chamber. The diaphragm is constructed by stacking a metal film and a flexible plastic film in layers so that the films are independent of each other.

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.

Abstract: A pressure switch for controlling the pressure of a refrigerant has a first switch normally open biased, which first switch is used for a condenser, and a second switch normally closed biased, which second switch is used for a compressor. The three-function pressure switch has a pressure chamber partitioned by a diaphragm. First to third movable elements urged toward the diaphragm are displaced in response to the pressure applied via the diaphragm. Displacement of the first and second movable elements is restricted by a stepped portion of the housing. An actuating projection provided on the third movable element presses upward a second leaf spring of the second switch at a lower limit pressure value so as to open the second switch. When the pressure reaches a normal maximum value, a first snap disc mounted on the first movable element actuates the first switch via a push rod. First snap disc and the push rod are restored at a minimum pressure value.