DETACHABLE DRILL BIT Russian patent published in 1998 - IPC

FIELD: drilling equipment. SUBSTANCE: invention refers to two and more cone drill bits. Detachable drill bit is fitted with gear transmitting axial load on to sections of drill bit, with locking device that holds sections in body of drill bit. Each section has capability for axial movement and internal surface of body of drill bit and external surfaces of sections are equipped with coaxial ring grooves to house locking device. Grooves in sections of drill bit have bigger width to provide for vertical movement of sections. Gear transmitting axial load on to sections of drill bit includes thrust journal having spherical form on one side mated with spherical socket of thrust bearing and interacting via spherical supports with sections of drill bit in vertical planes passing through axes of journals of sections of drill bit. Locking device is made in the form of split ring of rectangular section, for instance. Members of interaction of body of drill bit with its sections are manufactured in the form of grooves corresponding to bosses of sections in shape. EFFECT: improved functional reliability and efficiency of drill bit. 3 cl, 3 dwg