| 摘要 |
<p>A laser cutting head includes a lens for producing a waist in a laser beam, an internal chamber having an inlet for pressurised gas, an outlet nozzle for both the laser beam and a jet of pressurised gas which communicates with the internal chamber, an inner hollow generally cylindrical lens holder which holds the lens. The lens holder has a body which (i) makes sliding engagement with an outer sleeve, (ii) holds the lens and (iii), in use, is axially displaceable away from the nozzle. A plurality of transverse pins extends through slots in the outer sleeve to engage the body of the lens holder, and an outermost adjustable limit ring the axial position of which is able to be reproducibly set, and which engages the sleeve, the adjustable limit ring defining the axial position of the lens holder.</p> |
