Expert: John Newman - 1/24/2011

Question
MY EMPEROR CLOCK MODEL 101 MOVEMENT,ONLY GONGS ONCE ON EVERY HOUR.
THIS HAPPENED ONE OTHER TIME BACK IN 1997.I HAVE IN MY NOTES,IF ONLY ONE GONG ON ANY HOUR,MOVE HOUR HOOK ASSEMBLY TO 10 OCLOCK
PART #[15-27] BUT I CAN,T REMEMBER HOW TO DO THAT.AM I ON THE RIGHT TRACK? WHAT ARE YOUR THOUGHTS.
                       THANK YOU,
                                 LEE

Answer
Lee, I'm not sure where you got that information, but I believe it is a little confusing.  Emperor called the part #15-27 an hour hook assembly.  Most clockmakers call it the rack hook. I cannot see why it would be moved to 10 o'clock to correct the problem.  There are some instances where the rack tail can become lodged behind the snail. When this happens the minute hand can be turned backwards to the 12 o'clock position and it will free up the rack tail.  Your movement, like most modern production models are "safe back", which means you can turn them backwards safely.  But I don't think this is happening.  

Let me explain what could be the cause.  The mechanism that determines the number of hour strikes is called the rack and snail.  The snail looking cam is found on the hour tube and has 12 sections on it, each being a descending level from the outermost one which is the first level for hour 1.  As the chime completes its hour chime, it lifts the rack hook and allows the the rack tail to drop to one of the levels, and the rack hook engages the rack tooth corresponding with the hour to be struck. A cam (called the gathering pallet) with a pin on it rotates and lifts the rack one tooth at a time until the rack hook passes the last tooth and drops down and stops the strike.  When a clock strikes only once for every hour, it is usually the result of one of two things.  It could be that the lubricant in the rack hook pivot is gummy and/or there is a bind so that the rack does not drop past the first lever, thus striking only once.  The second could be that the series of levers from the chime mechanism is not lifting the rack hook far enough to clear the rack teeth.  Therefore, it catches and remains at the first level and strikes only once.  As you mention the parts of the movement which can only be accessed when the dial is removed, have you done this before?  If you are capable of doing it, you can observe what is happening with the dial removed.  If the problem is because of insufficient lift, the cause has to be determined by which mechanism has worn or is out of adjustment.  This might require the services of an experienced clockmaker, as making the incorrect adjustment can affect other interacting parts.  Let me know what you find.  I just remembered, I have a couple of labeled photos showing the parts we are talking about.  If you will reply to my email address below, I will email them back to you.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama

klokdok@juno.com

(Due to the number of Allexperts questions and
the workload I have at my clock shop, I regret
that I cannot answer personal email questions on a timely basis
other than Allexperts follow ups.)