FLAME SPRAY GUN

摘要

A flame spray gun (10) for feeding and melting rods (R) of heat fusible material and spraying molten droplets thereof onto a substrate comprising an improved main supply valve connected to air, fuel gas and oxidant conduits (14-22) (44-48) including air, fuel gas and oxidant inlet and outlet chambers (28-38), continuous seals (40) and vents (42) between the chambers, a valve shaft (50) with axially spaced slots movable within a bore and seals to connect the inlet and outlet chambers, a valve locking device (54-56) for maintaining shaft (50) either in a LIGHTING or ON position and an unlocking device (62-66) to release biased valve shaft to an OFF position. An improved combustion head (70) and flame spray nozzle (82) has seals situated on opposite sides of oxidant and fuel gas chambers and between the combustion head and nozzle. Further an improved turbine (130) comprises angularly spaced air jet passages in a shroud for simultaneously directing air under pressure from a surrounding sealed chamber against the turbine rotor (140) and axial exhaust passages between the air jet passages and a speed control for selecting, sensing and regulating the turbine comprises a throttle valve including differential pistons (172-174) responsive to back pressure created by movement of a magnet (160) within a magnetic cup (168) rotating with the rotor (140) which produces eddy current force torque which rotate the magnet (160) and an air jet obstructer (162) relative to an air jet orifice (164) and thereby vary the back pressure which acts to shift the throttle valve which adjusts the air supply and maintains the speed of the turbine accordingly to a constant preselected desired rate.