Abstract: A wire thermal spray gun such as a two-wire arc gun has a speed regulator for a DC pull motor in the gun. Armature current corresponds to pulling torque on the pull motor depending on load resistance of the wires. A DC push motor is between a wire supply and the gun, with wire conduits connecting to the gun. A controller provides the push motor with a controlled pushing torque. Feedback of the armature current of the pull motor to the controller adjusts the pushing torque in direct response to change in the pulling torque, such that load sharing is maintained between the push motor and the pull motor.

Abstract: The front face of the nozzle of a plasma spray device has a shallow annular recession therein. The recession is bounded inwardly by an extended portion of the nozzle, outwardly by a ring member and rearwardly by an inner surface. The ring member has therein a plurality of arcuately equally spaced holes directed radially inward toward the inner face, the holes communicating with a source of air. Powder is injected radially into the plasma stream external to the nozzle member proximate the outlet end. The air flow from the holes and entrainment of surrounding atmosphere by the plasma stream drive a toroidal vortex anchored in the recession, the vortex effecting a wiping flow on the nozzle face such as to inhibit powder from depositing on the nozzle face.

Abstract: An arc spray gun is adapted to spray coatings in confined areas. An arc spray deflector includes a nozzle body with a nozzle seat thereon and a hole therein receptive of a flow of compressed gas. A first nozzle insert is sealingly insertable in the hole and has a first flanged end with a first thickness positioned on the nozzle seat and further has an orifice therein to direct a lateral deflecting jet of the gas toward the point of contact of the arcing wires. A second nozzle insert is sealingly insertable in the hole and has a second flanged end with a second thickness. The first and the second inserts are adapted to be interchanged whereby selection of the distance from a respective exit point to the point of contact is effected.