Expert: Martin Meyer - 1/11/2010

Question
I have an Abel Cottey" grandfather clock(1970) that chimes a little tune every quarter hour progressive 1, 2, 3 then 4 times 3 minutes late then on the hour it only bongs 1 time no matter the time 2-12 o'clock am or PM.  any thoughts ?

Thanks,
Frank

Answer
Hi Frank,

Your clock has a "rack and snail" strike mechanism. I have attached a photo to help illustrate; it will not be like your clock, but the basic parts will be the same. On the hour, the rack hook lifts, releasing the rack to fall. The rack tail stops the rack from falling at the correct point by coming to rest on the correct step of the snail.

In your clock, the rack is not dropping all the way, and one common possibility is that the rack hook is being lifted only enough to allow the clock to strike once, as it does on the half hour. There is a whole series of interacting parts which cause the rack hook to lift the correct amount, and adjusting one part often throws several others out of adjustment. Therefore, diagnosis can be a difficult problem. Because this is a very technical issue, I would recommend having a professional clock repairer look at your clock.  http://www.clockmasteronline.com