Stem-Setting and sleeves and Detents and Pocketwatch Cases

Earlier American pendent-set pocketwatches have the mechanism that snaps in and out as part of the case.  In the neck of such a case there is a "sleeve" with spring fingers that grip the winding arbor.  A shoulder on the arbor snaps to one side or the other of the fingers when you pull it out or push it in.

Later watches have an improved design where the snap is part of the movement instead.  The winding arbor is free in the neck of the case, but held in the movement by something called a "detent" which acts as a lever, changing from winding to setting.  This is how the vast majority of mechanical watches work to this day.

This pocket watch has a detent.  Interestingly, I found the broken remains of a sleeve threaded into the neck of the case.  This case may be older than the movement, or perhaps it was designed to work either way.  But it does seem that at some point an older style movement was in this pocketwatch case.

I included in this photo a normal (not broken) sleeve for an example.