Abstract: In conjunction with a vehicle borne infrared receiver, sign indicia are defined by infrared reflective surfaces oriented so as to reflect infrared radiation to the receiver from a contrast enhancing source of radiation such as the sky and/or the ground thereby improving the contrast of the sign indicia within the displayed image.

Abstract: An infrared imager and a color TV camera view the same scene and the output signals are mixed and fed to a color television monitor so that the scene at night is visible in a black and white format with warm objects appearing dark, and bright colors such as lights appear in natural color superimposed on the black and white image.

Abstract: A prechamber type diesel engine is provided with a cutoff valve in the throat connecting the prechamber and main chamber of each cylinder and operable in cyclically timed fashion to close and open communication between these chambers. Methods of engine operation are disclosed which utilize the cutoff valve to (1) trap combustion products in the prechamber from the previous expansion stroke for use in mixing with the fresh charge in the following compression stroke to provide internal EGR preferably stratified in the prechamber and (2) permit low compression ratio starting by trapping compression pressure in the prechamber from a previous compression stroke for addition to combustion chamber pressure developed on the following compression stroke to provide a higher cylinder pressure for starting than that provided by the overall compression ratio. Advantages of improved engine efficiency and reduced emission levels are anticipated.

Abstract: A prechamber type diesel engine is provided with a cutoff valve in the throat connecting the prechamber and main chamber of each cylinder and operable in cyclically timed fashion to close and open communication between these chambers. Methods of engine operation are disclosed which utilize the cutoff valve to (1) trap combustion products in the prechamber from the previous expansion stroke for use in mixing with the fresh charge in the following compression stroke to provide internal EGR preferably stratified in the prechamber and (2) permit low compression ratio starting by trapping compression pressure in the prechamber from a previous compression stroke for addition to combustion chamber pressure developed on the following compression stroke to provide a higher cylinder pressure for starting than that provided by the overall compression ratio. Advantages of improved engine efficiency and reduced emission levels are anticipated.

Abstract: A multi-apex rotor for an internal combustion rotary engine is provided on its radially outwardly facing flanks with hot plates which each form a portion of a combustion chamber and have a shape and coefficient of expansion in relation to the rotor body so that they are normally separated within their periphery from the adjacent flank by a sealed air space so as to be insulated therefrom and thereby retain a substantial portion of the heat of combustion and on hot plate temperature rise with engine speed and load to a level below that which would cause pre-ignition expanding radially inwardly to establish a substantial heat conducting relationship with the flank to thereby limit hot plate temperature to below the pre-ignition temperature.

Abstract: A rotary combustion engine rotor having spark plug receiving recesses formed in its respective peripheral faces, each recess releasably mounting an elongated spark plug assembly. The elongated spark plug assembly is configured for insertion and removal through either an exhaust port in the engine housing or through an access port in the housing, the latter being closed by a suitable plug having a thickness less than the engine housing. The provision of an elongated plug having one or more spark gaps provides a means for mounting the spark plug assembly on the rotor and for the insertion and removal thereof without engine disassembly.