Abstract: A heater plug is cooled with combustion air for diesel oil-burning heating appliances, especially those provided with a vaporizing burner. The plug is screwed into a burner pipe joint, enclosing but spaced inwardly of the plug. The pipe joint also has inlet for supplying the fuel, and it is fastened to the furnace wall of the heating appliances. The burner carries a continuous lengthwise bore, accessible from one end face and opening into the heater plug coil, the inner end of the bore being connected to the combustion air channel across a proportioning throttle.

Abstract: An engine-independent heater, particularly a space heater for automobiles comprises a housing which includes a combustion chamber and an antechamber which is tangentially connected into the combustion chamber. The antechamber receives a fuel and air mixture which is ignited in the antechamber and directed into the main combustion chamber. The construction includes the housing carrying an ultrasonic vibrator which is actuated in order to intermix air which is drawn into the housing for the vibrator with fuel which is directed against the vibrator so that the coolant air intermix has there delivered into the antechamber of the heater. The construction includes a nipple connection into the antechamber which sprays fuel from a proportioning pump into the vicinity of the ultrasonic vibrator.

Abstract: A method of manufacturing parts which are otherwise identical but which display different indicia such as a typewriter or the like keys which comprises the steps of injection molding a plurality of identical parts of a plastic having a filler material capable of undergoing a color change, and thereafter exposing individually the identical parts to a radiation source for changing the color of localized portions of the part to display the indicia while retaining the molded color of remaining portions.