Abstract: The combination of a shot sleeve and a shot cup base form a universal shot wad that precisely fixes an adjustable volume for the shot column of a wide range of shot shell loads. The shot sleeve is a generally tubular member with an open end and a closed end. The inside of the shot sleeve is substantially smooth adjacent to both the open end and the closed end and has a plurality of substantially parallel, inwardly projecting, first ribs circumscribing the inside between the smooth portions.The shot cup base is a second tubular member and also has an open end and a closed end. A plurality of substantially parallel, outwardly protruding, second ribs circumscribe an outside of the shot cup base. The volume of a shot receiving portion is controlled by inserting the shot cup base a desired distance into the shot sleeve such that the two sets of ribs interengage.

Abstract: There is provided an anode for an electrothermal arcjet thruster. A conduit running through the anode body has a converging upstream portion and a diverging downstream portion connected by a constrictor portion having a greater diameter at the interface with the upstream portion than at the interface with the downstream portion. As the result, the cross-sectional area available to a propellant gas passing through the constrictor constantly decreases and the propellent gas velocity continually increases. This constrictor geometry allows the arcjet thruster to be operated at a lower mass flow rate increasing the obtainable specific energy.

Abstract: An assembly for producing printing plates from photopolymerizable resins includes an upper fixture assembly and a lower fixture assembly. The upper fixture assembly includes an upper glass plate, and an upper shutter box in which an upper UV light source is located. The upper fixture is mounted on a guide post so that the upper fixture assembly can be raised and lowered relative to a lower fixture assembly. The lower fixture assembly includes a lower light bank table containing a lower UV light source, and a lower glass plate on which the resin layer is cast. A doctor blade is drawn over the resin layer to smooth the latter on the lower glass plate. The resin layer is then exposed to UV light through a print pattern-defining negative so as to selectively harden the resin layer and form a printing plate that is defined by the negative pattern.

Abstract: Printing plates are formed from a layer of photopolymerizable resin by a process and assembly which involves moving a resin layer past a variable intensity light source so as to sequentially and selectively cross-link the resin layer as the resin layer moves past the light source.