(under subclass 327) Apparatus in which the bit is provided with (1) relatively movable parts which are adapted to move during operation to provide a new cutting edge or (2) a body in the form of repeating similar structure extending longitudinally of the bit such that a new cutting edge is provided when the original cutter edge becomes worn.
(1) Note. Under part (2) a mere homogeneous bit body which inherently wears away is excluded, some specific repeating structure, such as for example, separate defined layers of specific material, symmetrically arranged apertures in the bit body or a cutter element combined with a backing member made of different material such that as the cutter element and backing member wear an effective cutting edge will be provided, is necessary for classification under this definition.
SEE OR SEARCH THIS CLASS, SUBCLASS:
331+, for rolling cutter bits having plural cutting edges which are used successively and continuously.
382+, for adjustable cutter elements which are not adjustable during operation and particularly subclass 383 in which the adjustment is for the purpose of presenting a different cutting edge.
409, for a homogeneous bit-body made of some specific abrasive resistant material.
