CHESS CLOCK Russian patent published in 1995 - IPC

FIELD: instrument engineering. SUBSTANCE: sand flasks are disposed in mutual perpendicular one to another and fastened on both sides by means of insertions with spherical grooves inside cylindrical case made in form of a cup. Distance between the flasks is minimal and equal to external diameter of contracted part of the flasks. The flasks are protected by transparent disk. Rests are mounted onto external surface of the case for engage with lamellar spring which has slopes and grooves; as a result smoothness of contact is provided when case is stopped and fixed. EFFECT: improved precision. 2 dwg