Champion Spark Plug Company

Robert A Mahaney

Frank John Raeske

Richard E Callahan

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. The terminal assembly comprises a heater terminal which is electrically connected to the second end of the heating filament, and at least one preheat terminal which is electrically connected to an intermediate coil of the heating filament. The rise in temperature of the heater is accelerated when a switching circuit enables application of the specified voltage to the preheat terminal(s) for a preheat time period equal to the time required to raise the temperature of the filament from ambient temperature to the design temperature.

Glow plug

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. The apparatus comprises means operable, after the switch has been turned from the first to the second position, to actuate the power switch for a preheat time period which varies as an inverse function of available supply voltage and equals the time required to raise the temperature of the filament from ambient temperature to the design temperature. The apparatus also includes means operable, after the preheat time period, to alternately actuate and then deactuate the power switch in a cyclic fashion to maintain the design temperature of the filament for a prestart time period. The apparatus also includes means operable, after turning the switch from the second to the third position, to continue the cyclical actuation and deactuation of the power switch for an afterglow time period predetermined by the amount of time required for smooth engine idling and to minimize engine noise and white smoke emission.

Growing community of inventors

Graytown, OH, United States of America

Robert A Mahaney