Device for fastening a holding part on lenses

The invention relates to a device for fastening a holding part on lenses, of the type comprising, for placing a gripping block (12) onto a spectacle lens (10) waiting on a stage (11), a holding arm (16), designed for receiving the gripping block (12) removably, and a carriage (20), on which the holding arm (16) is mounted pivotably between two positions and which is itself mounted movably between two positions along a path in the course of which the holding arm (16) is presented automatically in line with the stage (11). According to the invention, since the carriage (20) is at least partially mounted movably in a straight line in a first direction (D1), the pivot axis (34) of the holding arm (16) extends in a second direction (D2) orthogonal to the first, and between this carriage (20) and this holding arm (16) is inserted a transmission (30) capable of causing the holding arm (16) to change from one of its positions to the other when the carriage (20) changes itself from one of its positions to the other. The invention is used especially in centring devices.