Abstract: A lighted switch set gauge includes Hall effect devices using a circuit activating switch attached to a lower extension of indicating and switch set pointers. The switch set pointer is externally adjustable. An overriding slip gear with automatic spring-back is incorporated in the switch set arm prevent damage to the set pointer at the extreme ends of its range of movement. The indicating pointer can be calibrated without removing a hub attached to the shaft of the gauge meter movement.

Abstract: A condition responsive sending and indicating unit for sensing a condition and transmitting a signal representative of the sensed condition to an indicator at a remote location. The sending unit includes indicia for giving an indication of the sensed condition at the site of the unit, and has a movable contact operatively associated with a variable resistor in circuit with the remote indicator, whereby a variable signal is produced in response to variation in the sensed condition. Calibration of the unit is accomplished by adjustment of the set point of the movable means, and by adjustment of the position of the resistor relative to the movable contact.

Abstract: A dump valve for dumping liquid from the bottom of a tank comprising an elongated valve body insertable into the lower end of the tank so that the valve body extends deeply into the tank, the innermost portion of the valve body having an inner port communicating with the interior of the tank, the valve body having a portion extending exterior of the tank when the body is inserted into the tank, the valve body having a central axial bore extending therethrough and communicating with the inner port for directing liquid away from the tank, a drain passage connected to the exterior portion of the valve body and communicating with the axial bore for draining liquid from the tank, a pair of head plates connected to the exterior portion of the valve body, the head plates being connected to each other and forming a diaphragm chamber therebetween, a diaphragm held in sealed clamping engagement between the head plates and dividing the chamber into two separate compartments sealed from each other, an elongated valve ste