Longines Weems (Small) Bezel Lock Rebuild- How Did It Work?

[rehajm]

There were many variants of the bezel lock and crown for the Weems. Usually there was a crown and a wedge part that prevented the bezel from turning when locked. The 2 o'clock position is the look I am going for...

...but the unit I'm trying to restore to function was held together with one screw wedged inside the case tube and screwed into the crown. The crown turns freely, unfortunately and would not lock down the bezel....

 

There was no wedge piece and this set up served only to keep the crown with the watch. Losing these parts was all but assured and replacements are nil. I've built the wedge part but I'm wondering if anyone knows how these were supposed to work originally as I cannot see the best solution? The tube is threaded as if there was a stem threaded to the case and a tip that threaded to the crown? As it stands the crown/screw combo I have is .80 and the screw head is 1.80. 

 

Edited June 10, 2024 by rehajm

[RichardHarris123]

It's a new one to me but it must of been a stem with two different sizes of threads, one to fit the crown the other to fit the case tube, maybe with a unthreaded bit between the two for the wedge. 

[rehajm]

Project update- now completed. I saw another weems where the locking crown was threaded and matched the thick diameter of the threaded case, the end inside was mushroomed so it would lock out before becoming detached. The crown I have had only the internal threads so I hunted for a replacement screw that would fit like the 'original'. A setting lever screw from a scrap movement had a .8 pitch and a head wide enough to wedge into the case and allow for unscrewing of the crown. I wish the screw was longer but it will allow the bezel to be unlocked and turned. The watch is a gift for a young pilot so I'll warn not to unscrew the crown too much. I found a donor movement with the extra long version of the seconds pinion spring so movement is working brilliant...

I made the little wedge part from a tiny piece of .015 annealed 1075 steel shim. My work is quick and dirty and wouldn't fly on a nicely finished case but my rough finish doesn't really show under the locking crown and matches the damage on the bezel quite nicely thank you ...

I have a bigger version weems on the bench at the moment. There are so many variants of case and movement they feel more like the days of hand made. I'll post the other soon....

Edited June 27, 2024 by rehajm