.~ Bit with leading portion (e.g., pilot) forming smaller diameter initial bore {6}
386
.~.~ Leading portion is separable starter
DEFINITION
Classification: 175/386
(under subclass 385) Apparatus in which the leading or pilot portion comprises a readily removable starter element for cooperating with the trailing portion to form a shallow, accurately positioned bore, the trailing portion then being described as usable independently of the starter element to continue the boring operation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
248, for similar structure comprising a core receiver removable through a below ground drill string.
