| 摘要 |
<p>In order to determine when a facet is complete when polishing a gemstone 5 and without discontinuing working in order to make the determination, a caliper 7 is fixed to the gemstone holder 3 and carries spaced sensors 12 which are adjacent and on either side of the stone 5. These sensors 12 respond to eddy currents induced in the scaife 1. When the sensors 12 detect that they are sufficiently close to the scaife 1, without touching it, a stone lift mechanism (not shown) is automatically actuated to lift the stone 5 off the scaife 1. <IMAGE></p> |
