Expert: Michael Radi - 11/26/2008

Question
QUESTION: I have a Hermle 340-020.It keeps good time.  The chime will not work.  If I raise the silence bar and then return it to the chime position it will then chime . But once at the next quarter hour position it will not chime.   I have cleaned and oiled.  Any advice on what to check

ANSWER: Dear Will, When you raise and lower the the chime on/off on the front of the movement you are actuating the chime in an exaggerated way. Meaning, you are lifting it further than the star wheel at the base of the handshaft.
This leads me to think that the lifting arm of your chime system has become bent at some point. Here is the way to check it:
With the face off or the movement out of the clock, put the minute hand on the handshaft. As you rotate the minute hand forward you will notice a V shaped lever lifting every 1/4 turn (the lifting lever is sort of a sideways V attached to the movement at the base of the V). This is your chime lifting lever. It is lifted by a 4 prong "star" cam that is staked onto the hand shaft closest to the front plate of the movement. The star cam has one high spot and 3 low spots, the high spot is for the top of the hour. It must lift higher to actuate the hour strike (more on this below).
1) First, make sure that the lower tip of the V shaped lifting lever is engaging the 4 prong star cam properly. (the lever sometimes gets bent from rotating the minute hand backwards). check to see that the lever is lifted all the way up each section of the cam. If it is not, you may have to bend the lower end of the V shaped lever so that it rides on the cam properly.
2) If the chime lever is riding on the cam properly and you still don't get a chime actuation then the V shaped lever is probably out of adjustment. Look at the top of the chime lifting lever and locate a pin on the top gear (just below the fan) on the chime side of the movement train. Check the top of that V and see if it lifts high enough to clear the pin on the chime wheel inside the movement plates. On every 1/4 turn the top of that lever should be lifted enough for the pin to exit the lever.
If the lever does not lift high enough to let that pin pass, you have to open up the V in the lifting lever so that the top of it raises higher. You have to make a careful adjustment to this V shaped lever. If you need to open up to V to increase the lift, place a pair of needle nose pliers inside the V and open them up so that the tips of the pliers press against the inside of the V. The cam lifts it higher on the hour than on the other 3 quarters.
The lever must lift high enough of the 3 quarters to actuate the chime but not the strike. When the high point of the cam lift, it has to also actuate the hour strike.
I hope this information helps you.
Michael

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

QUESTION: I have another Hermle 340-020.  I have cleaned and oiled.  But even if I adjust the balance wheel to the fastest setting it will still run slow. THis is the last of the modern clocks that I am still working on.  I do have a grandfather dated 1817 that I would like to ask about once I receive your reply.

Thanks again for the advice on the chime lifting arm

Will Long

Answer
Will, these movements are problematic for a number of reasons: Most of them were made with soft brass causing the barrels and pivot holes to wear out in about 8 to 10 years. It is usually less expensive to replace the entire movement (about $135.00) than to buy new barrels, mainsprings, and have bushing installed.
If you are sure the movement is in good running order I can give you a tip on speeding up the balance. If you have the old style balance with the coiled spring running up and down the balance tube (as opposed to the hair spring used in the newer movements) you will notice small punchings along the ring of the balance wheel. These small dots are partially punched out (some of them may be totally punched out). These act as weights and slow the balance down. You can speed it up by removing some of these punchings. For each one you remove, take another one out on the opposite side of the wheel so that you don't upset the balance of the wheel.
This is just a little tip and will work if the movement is in good shape and you are getting close to a full circle of rotation.
Let me know if you need more help.
Michael Radi
norkro.com