Jump hour (digital display) — Jumphour.jpg — Jumphour.jpg — Wallstonekraft · CC BY-SA 3.0 · source

Jumphour.jpg — Wallstonekraft · CC BY-SA 3.0 · source

Complication

Jump hour (digital display)

Also known as: Pallweber · Heure sautante

How it works

Discs printed with numerals replace hands; a spring-loaded star and cam make the hour disc jump instantaneously at the full hour, and in Pallweber's system minutes are shown on a second disc.

Why it was invented

A clearer, more modern way of reading the time; an early 'digital' mechanical display.

Invented: 1883 (patent)
Credited to: Josef Pallweber
Historical period: Industrial Revolution

Experiment in the Simulation Lab →

History and development

Josef Pallweber patented his digital display in 1883; IWC produced Pallweber pocket watches from 1884. Jump-hour wristwatches were fashionable in the 1920s–30s and returned with the mechanical renaissance.