Driving mechanism for perpetual calendar - gives automatic data indication except for february, which requires adjustment by hand

摘要

The actuating arrangement for a perpetual calendar uses a smaller number of parts and is more simply constructed than comparable mechanisms. The mechanism drive shaft holds a cog wheel, a data adjustment wheel, a month adjustment wheel, and a cog which engages with a pinion wheel. The periphery of the date wheel is divided uniformly into 31 sections, that representing the 30th day having a concave surface. The month wheel is rotated 1/122 or 1/24 of a full revolution ech month by a coupling. Its periphery is subdivided uniformly into 12 or 24 sections, each section corresponding to a month with 30 days having a concave surface. A lever pressing against both date and month wheels drops into the concave surfaces of both wheels when they coincide, so that a trip wheel which is normally moved by one cog each day is moved two cogs.