Abstract: A glow plug for accelerating the ignition of fuel in a combustion chamber of a diesel engine is disclosed. The glow plug comprises a shell releasably engagable with a head of a combustion chamber of the diesel engine, and an electrically conducting, tubular heater carried by and electrically connected to the shell. The heater has an open end within the shell, and an opposed closed end extending longitudinally therefrom. The glow plug also comprises a heating filament disposed within the heater adjacent to the closed end and electrically insulated from the tubular body thereof. The heating filament has a first end electrically connected to the closed end of the heater and a second end; it is one which heats to a predetermined design temperature when a specified voltage is applied thereto. The glow plug also comprises an insulator carried by the shell, and a terminal assembly carried by the insulator.

Abstract: Switch-controlled apparatus for actuating a power switch to enable application of power from an associated power supply to a heater filament of a glow plug in a diesel engine is disclosed. The filament is one which is heated to a predetermined design temperature when a specified voltage is applied thereto. The power source has a supply voltage greater than the specified voltage of the filament. A switch accessible to an operator of the engine is operable in a first position to prevent the application of the supply voltage to the apparatus, operable in a second position to apply the supply voltage through a first terminal of the apparatus, and operable in a third position to apply the supply voltage through the first terminal and through a second terminal of the apparatus and to a starter for the engine.