This was very popular in the 1980’s and was used mostly by Ridgeway Clock Company, but others as well. It is one of my favorites. The dial has not only a seconds feature but also date, date, and month sub-dials.The repair or replacement of the movement is straightforward if one keeps in mind a couple of details before any disassembly.

First, we assume that the secondary unit was working properly in the first place. Changing the date at midnight, etc.

Second, never take the secondary plate apart to clean, bush, etc. the parts may appear sloppy, but they came that way from the factory. The secondary set of plates come off as a unit. There are four screws, one on each pillar to be removed and the set of plates can be removed intact. Do not separate the plates.

MOST IMPORTANT! Before removing, set the clock to an hour. Any hour, but write it down for later. Now remove the secondary plate set. Do the repairs or replace the primary unit. Once that is done, set the movement to the hour that was predetermined. Now install the secondary plates on the movement. All of the calendars should turned at midnight.

Note that because of this feature, it acts like a 24 hr clock and you need to make certain it is midnight and not noon.

Thanks to Joe Hoenhous for the photo.