| 摘要 |
PURPOSE: To provide a permanent display timepiece displaying only by a gear. CONSTITUTION: The timepiece with a permanent calendar comprises a date wheel 6 having two stages and controlled by 24-hour rings 2a, 2b driven by an hour ring 1 by itself. The data wheel has superposed complicated gear train substantially constituted by three rotary rings 19, 20, 23 having protruding teeth driven by the 24-hour ring at the end of each month. The numbers of the teeth which must be advanced by one step (month having 31 days), two steps (month having 30 days), three steps (February of intercalary year) or four steps (February of the year except the intercalary year) at a date disc according to the positions of the three rotary rings to be decided by the rotation of the data disc are respectively one, two, three and four. The structure avoids all a lever, an oscillating rod and return spring except a jumper spring for indexing the data ring. |
