Device for lathe machining of optical workpieces of materials of non-brittle hardness

An apparatus for the machining of optical workpieces of non-brittle materials, comprising:

• a holder constructed for operative connection with an actuator for imparting reciprocating movement to the holder;
• a support fixable relative to the holder in a selectable one of two different positions and having a free end projecting from the holder;
• a cutting tip comprising one of a monocrystalline synthetic diamond and a natural diamond, the cutting tip being secured to said free end of the support and defining an arcuate cutting edge, a usable opening angle of which is limited up to 120° about a circle center point of the arcuate cutting edge;
• wherein the support has two abutment surfaces arranged at an obtuse angle relative to one another, whereas a planar co-operating surface is formed at the holder, the abutment surfaces being disposed so that the co-operating surface bears against a respective one of the abutment surfaces when the support is fixed to the holder, and
• wherein the circle center point of the arcuate cutting edge represents a virtual fulcrum of the support at the holder for movement of the support from one of said positions to the other one of said positions, thereby to dispose respective substantially different circumferential sections of the cutting edge of the cutting tip in a predetermined location for rotary machining of workpieces.