| 摘要 |
PURPOSE:To protect objective lenses against liquid simply by making the diameter of a head slightly larger than the diameters of the objective lenses, by providing a hemisphere to the head which machines the work by a laser while spraying a high pressure gas and expelling the external liquid with said gas and rotating the hemisphere according to the presence or absence of the high pressure gas. CONSTITUTION:A high pressure gas enters a working hard 1 through the inflow port 17 thereof and applies pressure on an air cylinder 7 through a path 16, thereby pushing a piston against the force of a spring 9 and rotating a hemisphere 3 clockwise around a shaft 4. Then, the gas feed ports 12, 13 of the hemisphere coincide with the inflow paths 14, 15 for the high pressure gas and further the gas blow ports 10, 11 of the hermisphere and the head coincide. When the high pressure gas attains the prescribed pressure or above, the gas blow out finally through the port 10, and while the external liquid is expelled by the gas in such a way, the laser light can be irradiated to the work. When the pressure of the high pressure gas drops down to the prescribed pressure or below, the piston of a cylinder 7 is pulled, and the hemisphere 3 is rotated counterclociwise by the force of the spring 9 until the same abuts on a stopper 6, then the port 10 is closed with the hemisphere 3, and an objective lens group 2 is protected against the external liquid. |
