World time clock with rotating time zone map - provided by disc cooperating with time zone scale around edge of underlying disc

摘要

The clock has a face indicating the time within the appropriate zone and a world map display marked with the different time zones coupled to the drive mechanism for the clock hands. The map display comprises an azimuthal projection printed on the surface of a circular disc (16) so that the pole coincides with the axis (17) of the clock hands. The disc is directly coupled to the hour hand (11) for rotation about this axis. An underlying concentric disc (21) has a projecting peripheral edge (22) carrying a 24 hour time zone scale and it is rotated in the same sense as the first disc from the hours tube or wheel (10) via a conversion gear (12, 13, 14, 15) with a ratio of 1.5 to 1. The clock is designed for compactness and easy read-out.