Wrist watch with supplementary hour hands for different zones - selects hands by rotation of subsidiary 24-hour dials, not driven by movement, performing differential hand rotation

摘要

The wristwatch has conventional central hour, minute and seconds hands (9-11) driven in conjunction with three supplementary hour hands (17) which rotate on smaller 24-hour graduated discs (16) distributed around the main dial (13). Each disc (16) can be set in four positions corresp. to different time zones, the chosen one being visible through a 90 deg. window (18) below the disc. The disc (16) and its supplementary hand (17) are reset by a single knob (39), but the hand (17) is driven by a differential mechanism which does not move the disc (16). ADVANTAGE - Provides three supplementary hour hands each serving four alternative time zones giving 13 indications altogether, which can be increased by substitution of different discs selected by user.