Abstract: The invention provides a lever displacement enlarging mechanism which is applicable for a positioning apparatus of an optical stage, is provided with bisymmetrical levers enlarging and transmitting a displacing force of an actuator element, and in which the distance between the leading end sides of boundary grooves and outer edges of coupling posts is smaller than that between the trailing end sides thereof and the outer edges and action point hinges are located closer to the axis of symmetry so that the fulcrum hinges and the force point hinges are closer to the outer edges of the coupling posts.

Abstract: A plasma gas is injected from a vortex flow forming hole defined to an insulator in a tangential direction with respect to the circumference of the arc column of a torch to enable the axis of the arc column to be aligned with the axial of the torch and a vortex annular gas sheath is coaxially formed to thereby narrow down a plasma flame. Further, the torch comprises the above insulator and a casing which are connected in series each other.

Abstract: A single torch-type plasma spray coating method wherein a gas flow in a nozzle of a plasma torch is made to be a laminer flow, thereby the plasma flame jetted from the end of the plasma torch is modified to be a laminer flow flame, the plasma is separated from the plasma flame which contains liquid droplets of molten spray coating material and runs toward an object to be worked by means for separating plasma arranged immediately before said object to be worked, and remaining droplets of molten spray coating material impinges on said object to form a coating film thereon, and an apparatus therefor.

Abstract: A multiple torch type plasma spray coating method and a multiple torch type plasma spray coating apparatus in which a main torch and an auxiliary torch are disposed so that their center axes may intersect each other, is improved in that laminar flow plasma is generated by the main torch, spray coating material is charged into the plasma flame in the proximity of the outlet of the main plasma torch, the plasma flame is blown onto an object to be treated, plasma is separated from the plasma flame just in front of the object to be treated, and the then left spray coating material is made to deposit onto the object to be treated.