Pressure responsive apparatus including valve actuating means

Claim 1

In combination with a pressure responsive switch having a housing and a pressure responsive diaphragm mounted in the housing and movable from a first configuration to a second opposite configuration the motion from the diaphragm transmitted to a movable electric contact which is adapted to move into and out of engagement with a stationary contact upon movement of the diaphragm from one configuration to the opposite configuration and a port fitting for reception of pressure to a surface of the diaphragm, the port fitting provided with a threaded bore, a bored adjustive screw disposed in the threaded bore and a spring extending from the screw to the pressure responsive diaphragm whereby the bias of the spring can be adjusted by movement of the adjusting screw, a coupling containing an axially actuatable valve and on which the port fitting is mounted, the improvement which comprises an actuating element positioned in the port fitting in alignment with the axially actuatable valve whereby the valve is actuated upon mounting of the port fitting on the coupling, the actuator element being formed of material having a first hardness and the port fitting is formed of material having a second hardness softer than the said first hardness and the element is pressed into and cuts threads of the threaded bore of the port fitting to lock it in place, the actuator element having a stem depending therefrom, the stem extends into the bore of the adjusting screw and fits loosely enough to permit relative movement between screw and stem and tightly enough to prevent any tendency of the actuating element to twist.