Abstract: A dust collecting apparatus wherein a plurality of elongate filter elements are periodically cleaned by a reverse pulse cleaning system which directs a reverse pulse of air through the open end of each filter element so as to remove contaminants which have collected on its external surface. The reverse pulse cleaning system has an air delivery pipe above each of the filter elements, and each air delivery pipe includes an air delivery nozzle assembly which includes at least one pair of transverse pipe sections which are transversely aligned and extend in opposite directions from the air delivery pipe, to define a cross-like configuration in plan view. A plurality of apertures are disposed in a linear line along the air delivery pipe, and at least one aperture is disposed in each of the transverse pipe sections.

Abstract: This invention relates to self cleaning dust collectors having top mounted filter cartridges. The top mounted filter cartridges include a top mounting plate having an annular flange and an outer peripheral lip to support and carry a sealing gasket. The outer peripheral lip provides lateral support for the gasket under the pressures involved during the operation of the dust collector, and it also serves to prevent over compression of the gasket. The dust collector is further provided with a reverse pulse air cleaning system which includes an air delivery pipe located above the filter cartridges, and with the air delivery pipe being spaced from the dividing wall a sufficient distance to allow for upward removal and easy replacement of the filter cartridges without extensive assembly and disassembly of the dust collector.

Abstract: A wireless microphone which does not require a separate antenna. A wireless microphone in the form of an elongate housing of nonelectrical conducting material with a microphone unit mounted in one end of the housing and a battery and control switch mounted in the other end of the housing. A first electrical circuit including an audio amplifier and a second electrical circuit including a radio frequency amplifier are mounted in the housing physically separated from each other and interconnected by radio frequency chokes. The output of the radio frequency amplifier is connected to circuit ground of the audio amplifier, with the microphone unit and first circuit serving as one radiator of a dipole and with the battery and second circuit serving as the other radiator of the dipole.