Abstract: The invention contemplates remotely operable lifting mechanism for selectively displacing a liquid-level float in a sealed tank, to permit checking of the operational status of the float throughout its displaceable range, and to permit check-out of magnetically operated electrical means actuated by the float at a predetermined float level within its displaceable range. The lifting force is coupled magnetically to the float without interference with the path of float movement and without interference with the magnetically operated electrical means.

Abstract: An apparatus for detecting variation of a condition in a mechanical device comprises a detecting transformer or plurality of such transformers provided with an input winding, a control winding and an output winding, an A. C. power source connected to said input winding, and a detecting element connected in series with said control winding. The normally closed detecting element is adapted to become open circuited in response to variation of the condition amount in said mechanical device. A required output signal is taken out and detected by an output circuit from the output winding due to the open circuiting of the detecting element.

Abstract: A radiator cap composed of a cap body, a compression gasket assembly connected to the cap body and adapted to open and close in accordance with the pressure of the coolant in the radiator, a float engaged with the cap body so as to move up and down in accordance with the level of the coolant. The upper edge of the float is formed so that upon contact with a gasket assembly, a valve is formed with said gasket assembly. A reed switch secured to the cap body is opened or closed in response to movement of the float so that the reed switch actuates suitable warning means when the level of coolant falls over a predetermined line.