Machine for grinding optical lenses

A machine for grinding optical lenses, of the type comprising:

• a grindstone set (21) mounted rotatably about a first axis (A-A′);
• a lens support (15) furnished with means (37) for rotating the lens (35) about a second axis (B-B′) which, at least during grinding, is substantially parallel to said first axis (A-A′);
• means (13, 39) for relative axial and radial positioning of the lens support (15) relative to the grindstone set (21);
• a tool-carrier assembly (17) comprising at least one tool (81;
• 83;
• 85) mounted integral with a tool-carrier shaft (75) rotatable about a third axis (C-C′), means (79) for actuating the tool-carrier shaft (75) suitable for moving the tool (81;
• 83;
• 85) between a retracted position and an active position in the vicinity of said second axis (B-B′), the third axis (C-C′) having an inclination that can be varied relative to the second axis (B-B′),
• the tool-carrier assembly (17) also comprising means (79) for controlling, on a value dependent on the value of the curvature of the lens, the angle of inclination (α) of the third axis (C-C′) relative to the second axis (B-B′) when the tool (81;
• 83;
• 85) is distant from the lens (35),
• characterized in that the control means (79) are suitable for retracting the tool-carrier shaft (75) via the control of said angle of inclination (□).