Abstract:
Die Erfindung betrifft ein Bohrwerkzeug (1), insbesondere zum Bohren von faserverstärktem Werkstoff (8), wobei das Bohrwerkzeug (1) zumindest eine Schneide (2) aufweist. Hinter der Schneide (2) ist in Vorschubrichtung mindestens eine, jeweils eine Quernut (3) oder eine Einschnürung begrenzende, Randfläche (31, 32) vorgesehen. Diese Randfläche besitzt eine Randkante (30, 30'), die zum Abtrennen von Faserstücken des faserverstärkten Werkstoffes dient.
Abstract:
In a device for limiting the advance of a drill during a drilling operation, which can be used in conjunction with a hand drill (15) or with an automatic manufacturing machine, the device comprising a housing (2) with a stop cage (2a) and a spindle (3) mounted rotatably and axially displaceably in the housing, and a stop (9) which is adjustable in the axial direction being arranged for limiting the advance, the invention consists in that the stop cage (2a) comprises a chip breakes (13) for breaking the chips, with a housing-side end and a free end, in such a way that it extends approximately parallel and directly adjacent to the workpiece surface and approximately radially from the outside towards the drilling tool (stepped drill bit 12) in such a way that its free end almost touches the countersink (12b) . Damage to the surface of workpieces is prevented by the invention, so that corresponding refinishing is avoided. Moreover, the removal of the coiled chips from the drilling tool previously necessary after each drilling cycle is dispensed with.