Patent · US Expired

Centering and working gemstones

US4417564A · kind A · utility

14Cited by
1References
11Claims
0Family size

Inventors

Key dates

Filing dateJun 1, 1981
Grant dateNov 29, 1983
Priority date
Expiry dateJun 1, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/87
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A rough gem stone is centered by mounting the stone on a dop, providing an image of the stone, as seen normal to the axis, providing a reference shape which corresponds to the shape of a cut stone, and superimposing the stone image and the reference shape, altering the size of one relative to the other until the reference shape corresponds to the stone that can be cut from the rough stone, and altering the position of the rough stone until the stone image registers correctly with the reference shape. In a method of working the stone, the final radial dimension to which the stone is to be worked is estimated and is used for terminating working when the actual radial dimension reaches the corresponding value.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.