Planetary gear for date mechanism in a wristwatch

US4443112A · kind A · utility

Assignee

• Timex Corporation · US

Inventors

• Gerhard Stotz · Eisingen, DE
• Adolf Sedlak · Pforzheim, DE
• Jean P. Skwarek · Besançon, FR

Key dates

• Filing date: Sep 29, 1982
• Grant date: Apr 17, 1984
• Expiry date: Sep 29, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G04B19/25
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A wristwatch with a stepping motor driving the hands through a normal gear train also includes a supplementary gear train driving a circumferential date ring showing the calendar date. The gear train includes a planetary gear assembly, which may also be selectively operated by an exterior manually rotatable button to change the date without interfering with the normal driving of the date ring from the stepping motor. Preferably the manually rotatable button is operable from the back of the watch using a ball-point pen or the like.