| 摘要 |
<p>1,246,481. Cutting glass. PILKINGTON BROS. Ltd., F. J. GROVE, D. C. WRIGHT, and F. M. HAMER. 21 March, 1969 [29 March, 1968], No. 15301/68. Heading C1M. Glass is cut along a desired line by effecting relative movement between the glass and a laser beam impinging thereon, which laser beam is of a wavelength to which the glass is' opaque, the energy density of the beam being regulated so that a stress field is set up in the glass along the line in question, and the glass is separated by a fracture which runs from a point of weakness along said line. The process may be applied to cutting or trimming sheet glass produced by the float or vertical draw processes. The laser may be traversed from a weakened point, e.g. a score in the edge of the sheet, so as to start the desired fracture, or the beam may travel towards the score so that the fracture runs back from the score along the line of energy application. Alternatively the score may be made after traversing the sheet with the laser. The glass may be subjected to mechanical stress after application of the beam, since the glass is not necessarily fractured immediately on applying the beam. The invention may also be applied to cutting other glass objects, e.g. tubes. In the embodiment illustrated a glass sheet 2 has impinging thereon a laser beam 10 produced by the laser 7, the beam being reflected on to the sheet by mirror 16 which is so mounted as to allow the beam to traverse the glass. The mirror may be of glass plated with gold on its front face. For cutting commercial glasses a laser with an output wavelength of 2À5-500 Á is used.</p> |
