Gyro-stabilized tool bit with wide, removable mounting adaptor for use in a wide mouth chuck

摘要

A tool bit includes a shaft portion having an adaptor end and a working end and a middle segment connecting the adaptor end and the working end, the middle segment having an average radius and a longitudinal axis, an adaptor base having an axial bore for receiving the adaptor end and having a fastening structure for removably securing the adaptor end within the axial bore, where the adaptor base has an average radius which is at least two times the average radius of the shaft portion middle segment, for enhanced tool bit stability, and where the adaptor base includes a lateral chuck engaging surface adapted to abut during rotational loading of the tool bit a corresponding lateral adaptor base engaging surface within a power tool chuck, and to abut the adaptor base engaging surface at a distance from the shaft portion longitudinal axis of at least two times the average radius of the middle segment so that the chuck engaging surface lockingly abuts the adaptor base engaging surface with a substantial moment, to resist adaptor base stripping and slipping, and to further enhance tool bit rotational stability. The chuck engaging surface preferably includes a substantially planar lateral face and the adaptor base engaging surface within the chuck also preferably includes a substantially planar lateral face.