Westminster chime movement stops chiming after an hour

QuestionEdit

QUESTION: Hi, I have a westminster chime movement (Hermle I think). I have had it from new for 12 years. The first 3 of which it was in abox while I built the long case. It never has consistently chimed. I can make it chime on the quarter hour and then the hour. But it stops chiming after a complete cycle. On the front of the movement there is a hook like lever that slips into a notch ( what I would call a 3/4 cheese i.e. one quadrant is missing from a solid brass wheel). If I lift the hook up, the next time it is due to chime it does and continues through the next hour chime, and then nothing. Any help much appreciated.

ANSWER: if you move the minute hand round to the quarters clock-wise it does: a)nothing b) does all the quarters except the hour quarter and strike. Which? a or b?

---------- FOLLOW-UP ----------

QUESTION: Thanks for the reply,

It doesn't strike the quarter or the hour, unless I have 'kick started' ( as mentioned previously), but if I have it strikes the quarters and the hours happily by moving the minute hand. If I leave it on it's own it will stop striking within the hour.

Dave

AnswerEdit

a worn movement will do this --but 12 years should not be it's problem in this case --

might be the lift lever that rides the back of the hand shaft and gets raised by the 4 lobed cam just in front of the front plate --it should lift the hook like lever that slips into a notch each quarter - watch it when it is not working and see if it is being lifted clear each quarter by that arm--may need to bend it closer to the cam? ( what I would call a 3/4 cheese i.e. one quadrant is missing from a solid brass wheel) advise