My 960 project watch is a bit of a sleeper. From the look of it, you would never expect it to be such a high end watch. Back in the day, you typically picked out the watch movement and then the case to install it in. So you could put an entry-level movement in a solid gold case or a high end movement in a simple nickel silver case. For my project watch, the movement was installed in a 25 year gold filled case. Based on the amount of wear thru, this case got a tremendous amount of use but the warranty expired 91 years ago.
The case back is engraved with a monogram but it's hard to tell what it is. I won't polish this case since the existing gold is very thin. I'll just give it a good cleaning.
Once the back cover is removed you can see the 21 jewel movement inside - and what a beautiful movement it is. The only distraction is the two holes on the balance cock that reveal the regulator spring / gooseneck is missing. Based on the catalogs, this movement shares a spring with other period calibers but only the 960, 961, 964 or 965. Unfortunately I don't have a donor movement to replace it. However, the safety of railroads is no longer at stake and the movement will be just fine without it.
The 960 is a lever set movement so you have to remove the front bezel and slide the lever at the 1 out a little to set the time. That's probably part of the reason for the extensive case wear - you need to unscrew the bezel to access the lever... do that enough times over 25 years and you will probably wear off some of the gold. You might also chip the dial a little, like this enamel watch dial shows.
Early Hamilton pocket watches had four dial feet. Eventually movements were changed to three dial feet locations so swapping dials from one movement to another requires having the correct number of feet. These dial foot screws are much smaller than other calibers I've seen. That's one of the challenges of really early Hamilton calibers, not all parts are interchangeable if you're missing something.
With the dial out of the way you can see how the lever will slide the clutch from the winding position (as shown) to the time setting position. It's a very simple mechanism but it was a requirement for railroad-approved watches - as a lever set movement cannot accidentally pop into the time setting position without your knowledge.
With the mainspring fully released, the first part off is the ratchet wheel. Now the movement is de-energized and can be carefully disassembled.
In this photo you can see one of the distinctive parts of the 960 movement - the train wheels are solid gold, except for the escape wheel. The escape wheel is steel and since it's what get's banged into by the pallet forks, steel is actually a premier material over other choices of the time. The ruby jewels are also set in solid gold.
The mainspring inside the barrel is a white alloy spring and does not need to be replaced (just cleaned).
Everything is thoroughly cleaned and dried so that now it can be reassembled with fresh lubrication. This movement is noticeably brighter and shinier than before - a testament to why cleaning is important.
Everything is reassembled with the exception of the balance. At this point I can wind the mainspring up a bit so that once the balance is back in place it will start ticking and show me everything is aligned correctly.
It's always a satisfying relief to see the balance start to swing back and forth with a vigorous motion. Now to see that the timer thinks of it.
When you hear the tick tick tick of a watch you're actually hearing several ticks in rapid succession. The impulse jewel on the balance swings into the pallet fork and moves it out of the way. The pallet for bangs into the banking pin that governs the travel of the fork and that releases the escape wheel. The escape wheel bangs into the other side of the pallet fork and is stopped by the other pallet jewel. That's all one "tick". Then the balance swings back the other direction, hits the pallet fork and moves everything once again. All of that is captured by the watch timer and compared to what is expected.
You can see in the photo below that this 960 is tick ticking a little fast but has great motion otherwise. The beat error of 0.0ms means the balance swings equally from one side to the other.
A slight tweak to the regulator slows the watch down and a couple of more tweaks get it to settle in to 14 seconds fast per day. I'll leave it there for now and check it again after a while.
I have 2 of these Ham. # 940`s. One is lever Set, the other is Pendent Set. I had a watch maker in TN. Do a COA on both of these # 940`s. Both have a new 4 foot Dials and new heavy style hands. They are my pride and joy. I also have a Ham.ReplyDelete
# 931. Took me 6 years to get. 48 Ham. in my collection !