Abstract: Process and device for cleaning pollutants from a surface using a laser for applying laser pulses to the surface to be cleaned, in which the laser is pulsed in pulse durations not exceeding 30 nanoseconds, the area on the surface is contacted with the pulsating laser, the surface is cleaned in the absence of an observably thermal effect, and the laser is removed from the area on the surface after the area is cleaned, the laser beam is manipulated by means of a hand piece, and an optical system is provided to separate the laser beam into a plurality of individual laser beams with energies approximately equal to each other, and guided by an optical fiber assembly together with a recombining of the individual beams into a single laser beam, and the afocal optical assembly for adjusting the diameter of the recombined laser beams.

Abstract: A staged tool for boring a hole in a heated element of a material such as metal. The tool is adaptable to being axially forced and operation of the tool causes plastic deformation of the bored material. The tool successively includes, beginning at its front end, a front cylindrical or conical end portion having a first relatively small diameter, a neck followed by a working portion of evolving revolution having a right cross-section which increases in the direction of advancement of the tool, whose major base has a second diameter greater than the first diameter. To improve lubrication during boring, positioned on the neck at the rear of the front end portion is a mass of solid lubricant having a fusion point less than the temperature of the element during the piercing operation. The solid lubricant melts when the tool penetrates into the heated element and the contact surface between the element and the working element is constantly lubricated by a melted lubricating film.