Uncovered Gear Train Wheels, Strange?

[Ishima]

Recently a customer came to us with a rather old and inexpensive Avia watch that had a rather peculiar ETA movement in it, 455.111 (maybe a 450.111) I believe was its serial, but I may have miss-remembered that. 

I took a picture with what I had to hand, so it's a bit blurry, but take a look. 


Perhaps the gasket should have been cleaned before the picture instead of after, hmn.

Anyway, as you can see a couple of the gear train wheels are not covered by any bridge or cock. 
At first I thought perhaps it had been cowboy'd and I was in for a little problem but then i could see no fixtures to hold a bridge, and could see no pivots, so it had to be by design, sure enough it worked okay once I carefully changed the battery. (you can see the wheels are unnervingly close to the battery.)

But I couldn't think of a time when I'd seen anything like this, is this as unusual as i think?, or is this an established way of configuring the gear train that I just by fluke hadn't seen til now? any thoughts or insights?
 

Edited April 12, 2015 by Ishima

[bobm12]

Very interesting movement! Thank you for postingit!

 

Cheers,

 

Bob

[Geo]

New one on me Ishima!

[seemore]

They used to put them in Mondaine railway watches, they are not made any more.

[Geo]

 

They used to put them in Mondaine railway watches

Is that because the movement looks like something off the railway? :)

[clockwatcher]

Geo, I'll have you know that a well-put-together locomotive is just like a watch!

 

Just a bit heavier!

[frenchie]

interesting... did the wheels fall off when you flipped the movement ?

[Geo]

interesting... did the wheels fall off when you flipped the movement ?

Hi Frencjie, they're actually designed to be like that. Do a Google search and you find other photos of the movement.

[frenchie]

Hi Frencjie, they're actually designed to be like that. Do a Google search and you find other photos of the movement.

 

Thanks Geo. I'm just wondering how they are held in place :) but it looks pretty cool like that !

[Geo]

Here's a clearer picture.

[bobm12]

It is the same way the canon pinion is held on ETA movements like the 2801 family...I think they call it a friction slot?

[WillFly]

Here's the tech sheet for ETA 450.111... looks like it.

 

ETA 450.111.pdf

[frenchie]

Here's the tech sheet for ETA 450.111... looks like it.

 

ETA 450.111.pdf

Key sentence :

"The hands must be fitted on a suitable movement holder with a central support"