Seth Thomas Wall Clock

This Seth Thomas wall clock came to me because it stopped running. It is a large wall clock that is well made. It is time only and is run by a weight. It does have a second hand which goes through the dial and affixes on the escape wheel.

When I took the dial off, I discovered that the cable had come off the pulley and was caught.

I replaced the cable. When replacing the cable you should measure the diameter and length of the old one. Assuming the old cable is the correct one for the clock. I also put new bushings in the clock. This is a simple movement, in that it has only one "train" of wheels. But the design was well thought out. In the picture above and below you can see it has 4 posts at the bottom and top of the plate. The two slightly larger silver ends are actually what holds the movement to the case bracket. The two black screws hold the clock plates together. This is the first clock I have seen that mounts to the case in this way.  

It has a key that you put on the square shaft that turns the drum. This winds the cable around the drum pulling the weight up.  When pulling up any weights, you never want to put any slack in the cables or chains. I have the minute hand on the clock while testing it. Before I put the minute hand on, the wheel behind the hand would take about 24 hours and it would move forward on the hand shaft and wedge itself against the washer on the minute wheel and stop the clock. If they all do this I was not aware of it. This is the first clock for me. So to run the clock, it has to have the minute hand on it to hold the hour wheel in place.

In my opinion, Seth Thomas did a excellent job, in both the style of the case and the quality of the movement.

Hermle Barrel Mainsprings

I see many Hermle movements in clocks. I have quite a few in my discarded storage area. They are from Germany but are newer movements and not made to overhaul. If yours is worn out then a new movement is installed.

They do have one good feature regarding the mainsprings that power the clock. The mainsprings are contained in a "barrel". You can take the barrels out of the movement without disassembling the whole movement. This makes it easy if you have a broken spring and want to replace just the spring.

The first thing you want to do is power down the clock. This is the most important thing in clockwork, so you do not get hurt and neither is there any cause for damage to the clock. Having a let down key is handy but if you do not have one, you can use the clock key. You want to put the let down key on the winding arbor. Turn the arbor slightly toward the winding direction to release the click paw from the ratchet wheel. Press up on the other end of the paw with your thumb. Press enough that the paw is away from ratchet wheel so the wheel can turn and let the key in your hand turn slowly. Be careful not to let the key get away from you. Slowly let the spring unwind. There will be a lot of force against the key in your hand. Having a let down key will make it a lot easier to unwind because of the smooth handle. If you are using a key, the wings will get in the way. Which means you will only be able to let down a couple of teeth at a time. You will have to continually stop and start letting down the spring.  

After the power is totally off the spring you can start to remove the barrels. The winding arbors have a bracket with screw around them that is holding the click wheel in place. By taking the bracket and click wheel off, you are now able to pull the winding arbor straight out toward you. Take notice of the groove along the winding arbor. When you later install it, the groove will have a position inside the barrel. The springs in the same clock could have different strengths so be sure and check the numbers on the outside of the barrels. Now you can install new barrels and reverse the whole process.

            

Delft German Clock

Here is a clock I bought a few years back at an auction. I was going to school to learn to repair clocks up in Pennsylvania. They had a lot of auctions and I liked to attend them and buy clocks to practice on.

The clock's front is ceramic. Its from Germany and the movement is marked CH. Schlenker Sohne, Schwenningen, Germany. Of course when I bought it, it was missing the pendulum and the key. I was able to buy the items that fit the clock. The first things that get lost are the keys and the pendulum because they are not attached to the clock or can come off.

This is a time only movement and you can tell from the dial as it has one winding hole just below the hand shaft. This clock is powered by a spring. In the picture you can see the small spring wound up at the bottom. In this time "train" there are six wheels between the plates. Because this is a time train we number the wheels starting with a T. The first wheel with the spring is T1 or the main wheel(which generates power up through the train). Then comes T2 wheel which meshes with T1 by a latern pinion. T2 wheel meshes with T3's pinion. T3 is on the center shaft. When the hands are on they are on the center shaft with T3. T3 wheel meshes with T4's pinion. T4's wheel meshes with T5's pinion. T5's wheel meshes with the escape wheel's pinion. And the last wheel is T6 or the escape wheel. Above the escape wheel is the pallet. As the wheels go up the train they get smaller and each wheel has a different number of teeth. There are two wheels on the front of the clock outside of the plates and are the hour wheel and the minute wheel.

The pallet above the escape wheel rocks back and forth and lets one tooth "escape" each time. The escapement gets the power from the spring to do this. If there was no pallet and the spring was wound up the power would make the wheels whirl around until all the power was released. The escapement is set up to let the power out gradually, one tooth at a time on the escape wheel. This is where you get the "tick" "tock" sound. The pallet has a crutch attatched to it and from there is a suspension spring, pendulum leader and the pendulum.

This is a basic clock but they get more complicated with more functions to perform. If you are into finding out how clocks work, hope you enjoy.