Concentric circle

from Wikipedia, the free encyclopedia
Round circle with ruler
approx. 1740

A circular circle , also known as a curved circle , is a watchmaker's tool for holding balance wheels or wheels to determine whether they run flat in the plane - or run over the tooth tips.

description

various round circles
at the bottom right, modern design with jaws that can be moved in parallel

With the simpler concentric circles in the form of an “ 8 ”, the hollow grains for receiving the pegs are not parallel to one another, but the more oblique the wider the jaws are opened. With the more modern compasses, the jaws with the hollow grains are shifted parallel to each other. In order to carry out a measurement precisely, a circular runner should have a fixable ruler (scanner).

Circular circles are available in many different designs.

Functions

Several functions can be checked with a circular circle.

  • Axial run : The balance or the gear is placed between the jaws so that it can be turned easily. The ruler is set at the minimum distance to the side of the wheel. When turning, the change in the gap between the wheel and the ruler indicates the lateral deviation of a wheel from its plane , which is perpendicular to the axis of rotation .
  • Radial concentricity : The wheel is reinserted between the jaws. The ruler is fixed to the wheel parallel to the axis of rotation. When turning, the change in the gap between the wheel and the ruler indicates a deviation in the shape of the wheel.
Circular circle
measuring the static unbalance
  • Static imbalance : The balance balance is usuallyusedfor this measurement. Instead, you can use the circular caliper if you provide its jaws with a series of notches on the inside. The balance is placed between the cheeks so that it can be turned easily, while holding the compass horizontally and running a watchmaker's screwdriver back and forth over the notches to trigger small vibrations. If there is an imbalance, the center of gravity of the balance is adjusted by the vibration below the axis of rotation.

literature

  • Theodore R. Crom: Horological shop tools, 1700 to 1900. Melrose, Florida 1980, ISBN 0-9604888-0-4 .

Web links

Individual evidence

  1. ↑ Circles of curiosity . In: Heinrich August Pierer , Julius Löbe (Hrsg.): Universal Lexicon of the Present and the Past . 4th edition. tape 11 . Altenburg 1860, p. 387 ( zeno.org ).
  2. ↑ Lukas Stolberg: Lexicon of the pocket watch. Carinthia Verlag, Klagenfurt 1995, ISBN 3-85378-423-2 , p. 194.
  3. ^ Frederick James Britten: The watch & clock makers' handbook. dictionary and guide. 1915. (Reprint: Baron Publishing, Woodbridge, Suffolk 1976, ISBN 0-902028-12-X , pp. 73f.).
  4. ↑ Hans Jendricki: The repair of the wristwatch. W. Knapp, Halle (Saale) 1948, p. 123.
  5. ^ Wilhelm Schultz : The watchmaker on the workbench. Verlag der Deutschen Uhrmacherzeitung, 6th edition. Berlin 1920, p. 437f.