Patent ID: 7377729

Claim:
A method of drilling holes in lenses for making “rimless and pierced-lens” spectacles by means of a numerically-controlled drill having a tool support that is mounted to move in translation in three co-ordinate directions X, Y, Z, the associated drill tool being drivable in rotation about and movable in translation along its axis which is parallel to one (Z) of said directions, said method comprising the following successive steps: a) positioning a lens (V) by moving it in a plane substantially perpendicular to the axis of the drill tool, relative to a reference pointer of position in said plane that is known to the numerically-controlled drill, until a pre-marked reference point (PR) on an edge of the lens (V) is brought into abutment against the reference pointer, whereupon said lens is held stationary in that position; b) then bringing the drill tool towards the lens (V) which continues to be held stationary, and retracting the reference pointer in order to leave clear the abutment zone of the lens; and c) controlling the drill tool so as to perform the pre-programmed machining sequences, by using the position of the reference point (PR) of the lens (V) as a zero point for said sequences.