Patent ID: 8931899
Filing Date: 2015-01-13
Classification: B24B,G02C

Abstract:
1. A process for shaping an ophthalmic lens using a machining device equipped with clamping means for clamping the ophthalmic lens, a machining tool for machining the ophthalmic lens and a force sensor adapted to measure a force that is related to the force applied by the machining tool to the ophthalmic lens, comprising: a step of clamping the ophthalmic lens in said clamping means; and a step of shaping the ophthalmic lens using said machining tool, in which step the loaded value of said force is measured and said machining tool is controlled, relative to said clamping means, depending on the measured loaded value, so as to bring the initial outline of the ophthalmic lens to a final outline of different shape, wherein said process comprises, between said clamping step and said shaping step, at least one intermediate step in which said machining tool is controlled, relative to said clamping means, so as to travel the circumference of said ophthalmic lens, without contact, following a path deduced from said initial outline, and in which the unloaded value of said force measured by the force sensor is recorded, which value is related to the forces required to move said machining tool in free space relative to said clamping means, considering the frictional and inertial forces at work; and wherein, in the shaping step, said machining tool is controlled depending on the recorded unloaded value.