TIME RECORDER JUMP HOUR 1970's
A recent find to my collection is this collectible Time Recorder from the 1970's. It is a big piece of watch on the wrist supported by a wide 28mm leather strap. It features a generic and very common BFG582 calibre hence I started wondering why it was always so popular in auctions reaching more than an average pin-lever jump hour. The mystery is now all clear...the Time Recorder belongs to the very small family of jump minute watches being a slightly less complicated invention than the electronic Gruen ESA9159 Electronic. The plain Baumgartner movement has been expanded by a jump minute module fitted on top thus making the watch thicker by approx. 2-3mms.
Please review the pictures in detail. The cannon pinion from the base movement has been fitted with a wheel which drives two gears which in turn move the hour gear as well as the minute gears. The minutes move separately: single minutes are driven by a brass wheel on the right whereas the 10's of minutes are moved by the silver star-shaped wheel in the center-right with a lever on top preventing the wheel from jumping more than necessary. Not that complicated if you analyse it in detail. This jump module would allow practically any mechanical movement to be changed to a jump minute. It would of course require increasing the thickness of the case nevertheless I'm puzzled why it was not commonly used in the 70's? Very smart!
Keywords: time recorder, jump hour
Market value:
50-150$ (1j. or 17j. movement, condition)