Manual or motor driven mechanical calculator - has mechanical toothed cam coupling discs enabling either drive to be used

摘要

The mechanical calculating machine may be operated by either a manual or an electric motor driven spindle. The coupling units are in the form of co-axial toothed cam wheels mounted on the same spindle. The wheel adjacent to the motor drive typically has six teeth mating with an arcuate lever arm with a locking tooth which engages with the cam teeth in such a fashion as to permit it to rotate in one direction only. The manual lever is mounted externally to the instrument and connected to the main drive by a chain drive arrangement and has a spring-loaded cam coupler which enables the manual drive to be disconnected.