A laser centering mechanism of a drilling machine includes a clamp ring fitted
around a drill chunk of a drilling machine, upper and lower knobs, and two laser
modules. The clamp ring has several spaced upwards-sticking flexible plates, and
several downwards-sticking flexible plates. The knobs are fitted around an upper
end, and a lower end of the clamp ring respectively. The knobs are securely screwed
to each other so that inner annular portions thereof make corresponding flexible
plates tightly and securely pressed against the drill chunk. The laser modules
are fixed to an inner edge of the lower knob, and are equipped with such lenses
that laser lights emitted therefrom form intersecting straight light lines on a
plane under them, which will form a centering light point on a central axis of
the lower knob in rotation of the present mechanism together with the drill chunk.
