| 摘要 |
The radial position of a gem stone 12 is adjusted using a special rotary support which is used when working the stone and has a body member 1, 2 for connection to a rotary mount and a stone holder 8. For adjusting, the stone holder 8 can be moved radially with respect to the body member 1, 2 whilst keeping the axes of the stone holder 8 and body member 1, 2 substantially parallel, and there is means 13, 14, 15 for applying to the stone holder 8 a frictional clamping force which is substantially less than that required to hold the stone 12 in position during working. After adjustment, the stone holder 8 is firmly fixed to the body member 1, 2 using fixing means 13, 16. <IMAGE> |
