Abstract: An orifice entry diverging multi vane conical venturi diffuser for a mortar tube that provides a surface at the discharge end of a mortar tube for measuring or sensing instruments. The internal,vanes comprise the primary surface and the conical venturi wall comprises the secondary surface. This apparatus allows a solid object of the equivalent diameter of the entry orifice when propelled by gas pressure to travel through the diffuser into the open atmosphere while at the same time providing an increasing volumetric flow path for the discharge of the propellant gas. The vanes axial parallel primary surface area is used to provide a port for instrumentation. The area between the primary and secondary surfaces of circumferentially spaced vanes provides the gas flow channels when the center section formed by the vanes primary surfaces is obstructed by a solid object with the equivalent diameter of the entry orifice.

Abstract: The amount of protrusion of an end of a standard length push pin from a stationary part of a solenoid-actuated valve is measured at a certain point in the valve fabrication process. Then before the armature is assembled into the valve, a depression whose depth is based on the push pin protrusion measurement is coined into the end of the armature that is to bear against the protruding end of the push pin. When the armature is assembled, the protruding end of the push pin seats in the depression that has been formed in the end of the armature with the result that the air gap between this end of the armature and the stationary part from which the push pin protrudes is the desired thickness. The process is well-suited for automated operation so that maximum production efficiencies can be attained.