Review of English pocket movement
Andrew Babanin
There's the last watch I worked on. Here there's my lovely English
pocket movement.
Fig 1. Just a blank dial
Its case was made of gold so it had been lost in time. The dial is in
pretty good condition except on the crack at 12. There was a lug to fix
the movement to the case. Maybe smb dismounted it with no care and
cracked the dial a bit. The movement is covered with special hood. One
turn of the blued arc clockwise - and it's open, CCW - closed. So I removed
the hood to show you the guts. Unfortunately, I do not have any info about
manufacturer except two letters "TF" (what date can it be?) on the hood and its serial number 94579.
The movement came to me in pretty good condition, so I even hesitated
whether any person serviced it. The problem was with the balance wheel - the balance
rim and roller rotated freely on the axis, also its hairspring was
deformed. The whole movement was dirty with old oil.
Fig 2. The movement is covered with
hood
This movement is based on a fusee, so the only way to release the
mainspring is a special ratchet wheel under the dial. Normally it used
to make the mainspring be wound at 1-1,5 turns (Its principle is close to the
Maltese cross - where we allow the mainspring to work in the special range:
not to be fully released or wound). One of fusee aims also not to let
the mainspring to be released or full wound. Changing length of the
chain we can find the moment when we use only working area of the
mainspring.
Fig 3. Pretty nice movement inside
The movement was full wound, so I inspected it carefully before any
step. I decided not to release the mainspring traditionally because of
the risk to damage it. So I had to remove the balance wheel first and
make its repair. After centering the impulse jewel and improving the
hairspring I mounted the balance unit back. I had to give some benzene to
all pivots to make the watch running. And after some manipulations it
became working. At first the amplitude was very poor, so it stopped twice.
Then the matters went better - it worked about 28 hours before stopping.
Afterwards I was able to release the mainspring without any trouble (just
repeat: with a special ratchet wheel under the dial). Then it was not a
problem to disassemble the whole movement. I was amazed with the quality
of finishing - all parts, including brass wheels were polished and
shined brightly like a mirror.
Fig 4. The fusee chain
After careful cleaning and lubricating I assembled the movement. The
only problem was to mount the chain back - if the mainspring is released
- the chain should be on the barrel, not on the fusee. But in this
condition it tries to slip from the barrel surface. After several
attempts I mounted all wheels, the pallet fork, the fusee and the barrel with a coiled
chain and covered it with the bridge. I also didn't forget to wind the
mainspring on 1,5 turns.
Fig 5. Another view
After some tunes the movement works perfectly. "Perfectly" means that the
watch gains 5 seconds per day! After a week testing it was about 30
seconds gaining. Pay attention that balance rim is made of solid gold!
There's no any temperature compensation device.
Fig 6. The balance rim is made of
solid gold. As to the endstone - it's a diamond.
What else? As I mentioned before, in post .... all watches of that
period had no setting square at the back. So if you want to set time -
just open the glass, find a square on the minute hand and using the key
set the time. Also notice that escapement wheel has two cap jewels -
quite rare for that period. As to escapement - traditional English one
(not Swiss).
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