Clocks, Watches/Striking Sessions Mantle Clock Info
QUESTION: I am from a country town in Australia where clock repairers are in short supply. I am repairing a Sessions 1927 tambour mantle clock for a friend. The main task was to replace the spring on the time train (erratic timekeeping).
Before disassembly I carefully photographed all that I could, but alas the strike train levers are between the plates making it hard to record their correct placement. After careful study I think I have worked it out however I have 2 questions.
Firstly a cam on the central arbor moves a lifting lever which in turn moves a lever that lifts the count lever out of its slot on the count wheel. This also lifts a stop lever away from the stop pin. Once the stop pin is released the stike train goes into warning.
Question 1 is "What holds the clock in warning?" I am guessing it is the J shaped lever that seems to sit between the stop wheel and the cam wheel (and serve no purpose).. Perhaps this is meant to go on top of the stop wheel and catch the stop pin when released?
Question 2 The cam pushes on a lifting lever. This, in turn, pushes on a short piece of metal attached to the hammer lever and lifts the hammer for the first strike. Currently this jams on the bottom of the lifting lever when the cam releases the lever. What is the correct position or shape for this wire so the levers don't jam?
Thanks, I hope my explanation is clear enough.
ANSWER: Bob, I apologize for the delayed answer. I was looking up some references for your particular clock and had a unusual number of service calls, etc. and did not get back to your question. I will get back with you on some answers sometime today.
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Thanks for getting back to me. As it turns out I worked out the answers to my own questions.
Question 1: Yes the J shaped lever is the warning lever that hold the Stop/warning pin in place during warning. It should be above the the stop/warning wheel to catch the pin.
Question 2: The extra wrire on the hammer lever is for the half hour strike. The cams on the central arbour are at different heights. The extra wire engages the top cam for a single strike.. The strike lever engages the bottom one.
I solved a final problem last night where the count lever did not turn off the chime. The movement has now been running since last night.
Half my frustration is that I could find very little documentation on how this movement works, especialy when a "J lever" means something else normally. I used another one of these movements for reference but it was more broken than the one I was fixing. So I thought I should "ask an American".
My final question, I am looking at buying books by Stephen Conover for reference. Do you reccomend them?
Thanks. I am aware that you offer your support for free so I hope I haven't wasted too much of it.
Bob, I am getting ready to go home after a long day at the shop. Just before I started to shut down the computer I was going to pull up your question so I could grab a couple of books to reference in explaining to you the function of the components of the strike operation. I was going to email you tonight. Guess who the books were by? Steven Conover. I highly recommend him. Great job in getting the movement running. I would also like to discuss your going into the clock repair field and how I might help. You sound like you might be a good candidate. I'll leave it right there for now and will be getting back with you. After I get back with you on Allexperts, we can exchange emails for some further discussion.
Sorry, but I cannot do any work tonight. Our home power failed as one half of the 220VAC (2 110VAC legs) is not working, so we have only have part of the circuits working and the power company is here turning the power off. I'll get back with you tomorrow.
Okay, last night the power company restored our service with a temporary transformer, so we are back in business.
On the strike function of the popular American turn-of-the-century (1900 era) clocks, the focus is on two arbors, having levers (mostly wire types) that control the strike initiation, number of strikes and stopping. There are variations between models and manufacturers. I'll stick with the one that counts the hour only and has three levers on the first arbor. About five minutes before the hour, one of the wires (lifting lever) is activated by the cam on the center shaft (minute hand shaft.) When the arbor rotates, it also lifts the unlocking and warning levers. The unlocking lever releases the pin on the warning wheel which allows the strike train to start moving. At the same time the the warning lever lifts the count lever on the second arbor. The count lever has been in a deep tooth on the count wheel and is moved out of the way. The drop lever is moved away from the cam. This is the cam with a notch in it and I have never heard any name other than "the cam". With some variations, the unlocking lever will catch the warning pin and stop the train. This is now in the warning pause. When the cam on the center shaft rotates to the hour it allows the lifting lever to drop and the strike begins. As the cam rotates, the notch passes the drop lever, but the drop lever will not drop unless the count lever drops into a deep slot on the count wheel after counting the correct number of strikes. This allows the warning lever to drop back down and stop the motion until the warning at the next hour. The whole warning function is like having to cock a gun before firing.
Of course all of this has to be synchronized, such as the position of the warning pin at rest. Also the pin wheel has to by synched so the tail of the hammer drops reliably just before the motion stops, and not to far after, so the train can get up to speed before the hammer lifts again, or it will possibly stall out.
As I said before, there are variations, depending on the configurations of the particular movement, but the process is about the same.
As I mentioned before, Conover's books are very good. I started with Clock Repair Basics, Clock Repair Skills, Striking Clock Repair Guide, Chime Clock Repair and How to Repair 20 American Clocks. I also had subscribed to his "Clockmakers Newsletter" for its duration of over 10 years. I understand he has revised and indexed the series which is available now. I like his publications because they apply to the beginner as well as the experienced clockmaker. One more thing and that is that I am a member of "Clocksmiths", a Yahoo Group devoted and limited to professional clockmakers. That means anyone that is in the business, basically where we charge for our services. We have about 700 members all over the world and I would say that about 40-50 of us are regular contributors. We discuss problems, techiques, tips, stories, provide parts and advice on running our businesses. There is no charge for membership.
Bob, below is my email address. Contact me and if you are interested in continuing with what good experience you seem to have and I will be glad to help you out.
Vintage Emperor Clock Consultant
THE VILLAGE CLOCKSMITH
137 First St
Prattville, Alabama 36067
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