DRILLING MACHINE Russian patent published in 2002 - IPC

FIELD: instrument making, in particular, medical equipment. SUBSTANCE: drilling machine has driving electric engine, whose shaft shank is joined through connecting member with inlet end of detachable tip pin. Connecting member is made in the form of coil spring. One end of spring has radial whisker bent inside. Electric engine tip share is equipped with axial end cavity. Inlet end of detachable tip pin has longitudinal slot and cylindrical external groove. Coils of coil spring are oriented in direction opposite to direction of rotation of drive shaft and end of coil spring is opposed to bent whisker. Coil spring is positioned in stressed state on electric engine shaft shank. Inlet end of detachable tip pin is embraced with other end of coil spring, whose radial whisker is located inside longitudinal slot of inlet end of detachable tip pin. Outer groove of detachable tip is disposed partially or in spaced relation inside axial cavity of electric engine shaft shank. EFFECT: increased efficiency and prolonged service life at increased rotational speeds of drilling tool working member. 9 cl, 3 dwg