There is a sub-second hand at 3 o’clock, and a power reserve indicator at 9 o’clock. An unusual set-up for a watch this age. Now where is that blasted crown? Nowhere! You can’t manually wind this watch, and it’s an early automatic. So this is where Seiko got their ideas from 😉
Here is the first clue… “Do not lift – slide”. The wheel on the back of the case sets the watch. No winding. If you slide it out, it engages with a wheel on the inside and you can set the time. Slide it back in, and it disengages.
First inside view. The centre wheel is for setting the time, and that’s where the sliding wheel on the case back engages. At 5 o’clock, there is a left-handed screw with an arrow pointing to it. This is used to let down the power, and my yellow oiler is engaged with the click that you can lift to let the power down. Essential if you don’t want to damage the movement.
The bottom plate is an engineer’s feast. As the slipping mainspring apparently wasn’t invented yet, these guys went completely overboard to tackle the problem of the automatic winding mechanism breaking the mainspring. At 9 o’clock, you can see that the oscillating weight has a little hook, that can engage with a pin. When the mainspring is fully wound, the pin will move outwards, and catch the hook of the weight, thus keeping the oscillating hammer weight locked, until the mainspring winds down a bit again, and releasing it. Mental 😉 If you had a wet dream about making this more complicated, you wouldn’t come up with this construction.
The mainspring in the barrel is pre-tensioned. As this watch doesn’t have a manual wind, the engineers thought it would be a good idea to leave a residual tension in the mainspring, so that the watch will start up instantly when slightly wound by the auto winder. Good thinking, but yet another complication.
Once the mainspring is pre-wound by 1 1/2 turns, two little screws are put into the centre plate. This plate rides up as there is a thread in the middle when the mainspring is wound. This serves to drive the power reserve indicator and the rotor catch pin that stops the auto winder once the watch is fully wound. The mind boggles!
The dial and hands go back on, and I can case the movement again.
Now for a word of warning… Not that this is a cheap watch to buy in the first place, but you have to make sure that the watch you buy is complete and working. There are no parts out there to be had, the movement is fiendishly complex, and is subject to quite a bit of wear and tear. So this is for Sunday best only, and for serious collectors that have time, money and patience.
Nevertheless, a piece of watch history, and one of the maddest designs I have seen so far. Probably the maddest.