Is there something written about the history or beginning of pendulum locks and mechanisms? I'm not aware of any early type locks, but have run across three basic locks on later clock which are by Kundo (sliding lever which grabs the upper collar of the pendulum), a sliding lever on the front or back which elevates the guide cup (Schatz coach clocks), and a guide cup which is raised by a threaded mechanism under the base (Kern). There might be variations on a theme, but when were locks first introduced? I didn't see anything in the repair guide but could have missed it. Thanks...Kurt
Did a bulletin search...found something in Vol 47 Issue 358 Page 570. Will have to read about it in more detail. Looks like some patents were issued in the 1953-1954 timeframe. Kurt
Eric - Thanks. Certainly, Reutter was well ahead on various things. I was thinking more along the lines of the other 400-day clocks...I don't recall see them on anything other than post WWII. The patents found documented in the NAWCC Bulletin all suggest that these began to flourish early to mid 1950s. Kurt
Aside from Reutter's clocks where the pendulum is not removable, there was probably no need to lock the pendulums until the massive sales following WWII resulted in greater losses from breakage. The Schatz pendulum lock introduced in 1953 is an obvious derivative of Reutter's design. Just a thought. Eric
The only Schatz locking mechanism that comes to mind is the lever that is slid from one side to the other to raise the guide cup and pinch the pendulum against a bracket...pretty typical on the coach clocks. The NAWCC article suggests a patent for Schatz that activated a pendulum lock with the clock was picked up...haven't seen one of those. Kurt
Gustav Becker was way ahead of its time as he had developed a pendulum lock for his cylinder escapement 400-day clock as early as 1872. Pictures below show the simple yet effective way the pendulum can be screw locked securely onto the upper part of base of the Gustav Becker escapement clock. The clock shown with serial number 105004 was made in 1875. Mun C W