Resonant acoustic beams modes are generated by an acoustic energy source and a plurality of reflectors disposed along a path.

In a separable mortar round of the type having a central cartridge chamber ithin the boom portion and provided with a plurality of flash holes extending outwardly of the chamber that improvement, which includes an adhesively bonded thin stainless steel foil disposed about the inner wall of the chamber and closing over the flash holes to provide increased liquid impermeability. The method of applying the aforesaid foil to the chamber wall by wrapping a foil on a hollow mandrel having a plurality ...

A method of insulating an attic cavity includes assembling a plurality of trusses to define an attic cavity, the trusses having sloped top beams so that the attic cavity has a reduced height end portion at least one end of the trusses. A screen material is applied to the attic cavity at the reduced height end portion of the attic cavity. Loosefil insulation material is blown into the end portion of the attic cavity to insulate the end portion of the attic cavity. The remaining portion of the att...

There is provided a laser mirror which produces an unusual type of laser output beam with certain desirable properties. For example, diffraction limited laser beams can be produced with large size components. The mirror is reflective, non-transmissive, and includes a plurality of spherical cavities therein.

A multi-cavity klystron device having a plurality of resonance cavities, comprising a plurality of movable elements, each of which is mounted on each of said resonance cavities and which is adapted to change the resonance frequency in each cavity, a plurality of tuning means for giving a reciprocal movement to each movable element against a resilient member provided therefor, a plurality of pulse motors coupled to the tuning means, and a preset means for controlling pulse supply to each pulse mo...

A system for feeding electromagnetic energy into a cavity for heating material contained therein includes a radiator of the electromagnetic energy and a motorized support for carrying the radiator within the cavity by the material. The radiator is constructed of a material such as alumina providing a much shorter wavelength than that existing in the environment surrounding the material to permit the radiator to have a sufficiently small size to be inserted within the cavity. Heat may also be pro...

A combined formwork and cavity tray element for use in the construction industry having first and second web portions joined together by a third web portion forming an included angle of more than 90.degree. with each of the first and second web portions. The first web portion is substantially straight throughout its longitudinal direction and the second web portion is curved in the vertical direction towards the plane containing the uppermost elongate flat surface of the first web portion. If de...

A compressor discharge valve assembly utilizing a cylindrical cavity in which is provided a discharge flow control valve and a valve stop for limiting the opening movement of the valve during operation of the compressor. The discharge valve chamber defines a cylindrical portion into which opens an outlet from the compression chamber. A cylindrical recess is provided in the wall of the discharge valve chamber for receiving a securing portion of the valve stop. The valve stop may further include a...

In a cavity identification system the containers, which are upright, will be in single file and will be diverted from a linear conveyor by a rotating starwheel, having in the periphery thereof, pockets which generally correspond to the external diameter of the containers. The starwheel serves to guide the containers from the side of the conveyor, in slightly spaced-apart fashion, over an identification station where the cavity identification reader is positioned. After the container has passed t...

The klystron amplifier comprises an input cavity a plurality of intermediate cavities and an output cavity which are arranged along the path of an electron beam for focusing it, and an output waveguide coupled to the output cavity through a coupling opening. The product G.sub.0 (R/Q)Q.sub.ex is selected to be where G.sub.0 represents the DC conductance of the electron beam, R/Q the characteristic impedance of the output cavity as defined at the gap between the edges of the drift tubes therein an...