System for polishing concave surface of e.g. glass of watch, has fixing device including displacing unit for displacing support, and grinding device having abrasive units whose contact surface is curved for polishing covering part

摘要

The system (21) has a fixing device (25) including a support (31) carrying a covering part made of crystalline alumina e.g. sapphire, corundum or ruby. A grinding device (27) includes abrasive units (33) mounted to rotate around a first rotation axis (A3) and for polishing the covering part along a first curvature (C1). The fixing device has a displacing unit displacing the support such that the support induces a back and forth movement (B) along a second rotation axis (A4). A contact surface of the abrasive units is curved for polishing the covering part along a second curvature (C2). The abrasive units are in the form of conical or curved shoe.