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The Encyclopedia of Horology

Glossary · Mechanism

All-or-nothing piece

A safety component in repeating watches ensuring the striking train either runs a complete cycle or does not start at all.

Explanation

In a repeating watch the wearer pushes a slide or pusher to wind the repeating mechanism and set the racks against the snails. The all-or-nothing piece ensures the watch strikes only if that action has been completed. If the slide is pushed only partly, the hammers stay locked and nothing sounds, rather than giving a wrong number of blows.

The part, invented in the eighteenth century, is usually a sprung lever that holds the hour rack or the striking train until the slide reaches the end of its travel. It protects the truth of the indication: a repeater that strikes the wrong hour is worse than one that does not strike at all.

What to record

  • Test by pushing the slide halfway and releasing: a correctly working repeater stays silent.
  • A repeater that strikes incomplete sequences may have a worn or misadjusted all-or-nothing piece.

Repeating work is intricate; do not operate a repeater forcefully or repeatedly if it misbehaves.