Abstract: A shock tube comprises a driver section, an expansion section connected to the driver section, and an extension connected to the expansion section. Shock absorbent material is disposed within a cavity defined by the driver section and extension section. At least one active vent is disposed over respective holes in the extension section that are connected to the cavity. The extension section is adjustable between one of at least two positions such that a length of the extension section in a first position is longer than a length of the extension section in a second position. The length of the gas column contained within the driver section can also be adjusted by the position of a movable bulkhead.

Abstract: A blast attenuator and ventilator for use in hardened or protective structures or the like that includes within a hollow housing a chamber that is arranged to receive directly the blast effect. Adequate openings for gas flow are provided so that appropriate gas flow for ventilation can occur therethrough.

Abstract: An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

Abstract: A fuel injection nozzle including a valve having an axial hole therethrough for feeding a first fuel to a collection zone and having a pathway for alternately feeding a second fuel to the same or different collection zone to enable the single nozzle to inject separate streams of each fuel into a compression ignition engine combustion chamber.

Abstract: A diesel engine having staged injection for using lower cetane number fuels than No. 2 diesel fuel. The engine includes a main fuel injector and a pilot fuel injector. Pilot and main fuel may be the same fuel. The pilot injector injects from five to fifteen percent of the total fuel at timings from 20.degree. to 180.degree. BTDC depending upon the quantity of pilot fuel injected, the fuel cetane number and speed and load. The pilot fuel injector is directed toward the centerline of the diesel cylinder and at an angle toward the top of the piston, avoiding the walls of the cylinder. Stratification of the early injected pilot fuel is needed to reduce the fuel-air mixing rate, prevent loss of pilot fuel to quench zones, and keep the fuel-air mixture from becoming too fuel lean to become effective. In one embodiment, the pilot fuel injector includes a single hole for injection of the fuel and is directed at approximately 48.degree. below the head of the cylinder.