Remotely readable fuel tank indicator system

Claim 1

A remotely readable fuel tank indicator system for a residential heating system, comprising: a fuel tank level gauge that includes a housing (47) having a transparent sighting window, a rotor having tank level markings thereon, visible through said window, a stationary potentiometer resistance concentric with said rotor, and an electrical slider mounted on said rotor for movement along said resistance in accordance with changes in the tank level; a D.C. current source remote from said gauge; a tank liquid level indicator means remote from said gauge; said indicator means comprising a casing (75) having a viewing window (76), a rotary stepper motor within said casing, and a visually readable pointer (81) mechanically connected to said motor; said pointer being aligned with said viewing window for indicating the motor rotational position; a first electrical circuit interconnecting said D.C. source with said potentiometer resistance and slider in said gauge; a second electrical circuit interconnecting said D.C. source and said motor; said first and second electrical circuits being connected in electrical parallelism so that said pointer provides a readout of the fuel tank level detected by said gauge; an electrical alarm circuit energized by said D.C. source in parallel with said first and second electrical circuits; a low fuel level alarm means associated with said liquid level indicator means; said alarm means comprising an electric alarm element (85) and a proximity switch (83) controlling current flow through said alarm element; said alarm element and said proximity switch being electrically located in said alarm circuit; and said proximity switch being located within said casing alongside the path taken by said pointer so that said switch is actuated when the pointer reaches a low tank level position.