In apparatus for generating and applying ionic charges to a web of film or the like operating in an explosive atmosphere of solvent vapor comprising an ionizer, a source of electrical energy connected to the ionizer, and means for supplying a stream of gas to the ionizer, the improvement comprising an air motor driving an electrical generator for supplying energy to the ionizer, and a single source of air under pressure connected both to the air motor and to the ionizer. Upon failure of air supply to the ionizer the motor automatically stops so as to discontinue the supply of electrical energy to the ionizer and avoid an explosion of the solvent vapor. Additionally a pressure responsive switch acts to open the circuit to the ionizer if the gas pressure decreases in the conduit leading to the ionizer.
An electrostatic spray gun apparatus for coating systems having an entirely self-contained light weight electrical power supply adapted to convert the kinetic energy available in a moving air stream into the required high d.c. potential and which dispenses with external electrical supply connections thereto.
An improved image transfer device for intermittently bringing a continuous image transfer medium into contact with the images on an image bearing member and transferring the images from the image bearing member to the image transfer medium. The image transfer device of the present invention utilizes an air pressure to bring the continuous image transfer medium into contact with and separate it from the image bearing member without the transfer medium and the surface of the image bearing member being contacted by a mechanical member such as an image transfer roller or bar or the like.
An improved energy converting and electric power generating system for electrostatic spray apparatus for coating systems adapted to convert the kinetic energy available in a moving air stream into electrical power.
An electrostatic spray apparatus wherein a charging chamber is formed as an enlargement in the conduit feed to the spray nozzle. The charging electrode is disposed axially of the conduit with a pointed end located at the exit end of the enlargement and facing upstream of a particle stream flow and opposed to a counterelectrode end located at the inlet side of said enlargement. The counterelectrode may be an obtuse end of an elongated element or may be formed as a grid extending across the conduit or as an annular element formed about a wall of the conduit. Optionally shown are a plurality of enlarged charging chambers, as annular element forming a constricted flow path and a charging electrode second end extending beyond the spray nozzle. Means introduce an air flow into the particle stream at both the nozzle and at the charging chamber.
The ionizer of the present invention comprises a chamber which has an ionization part that ionizes a portion of an ion carrier gas that is supplied to the interior of this chamber, and a blowing part which feeds the ion carrier gas toward a charged body. The ionization part is constructed from an ionization source which is contained in the chamber, and a control device which is connected with this ionization source via a high-voltage cable. Either the generating part of a soft X-ray generating device, the generating part of a low-energy electron beam generating device or the generating part of an ultraviolet radiation generating device is used as the ionization source. The control device, the connecting part between the control device and the high-voltage cable and the connecting part between the ionization source and the high-voltage cable are formed with an explosion-proof structure.
