Hi, i have a peculiar Longines: a 1953 automatic (originally) watch equiped with the 22AS movement. In my possesion this watch arrived without the automatic parts (rotor etc), but with the barrel mainspring adapted for being a manual winding mechanis. Now the real question (the above part was only to explain the bottom picture my watchmaker says that the hairspring is flat, not a Breguet hairspring, but in the late dr. Ranfft's site this movement has a Breguer hairspring. Were there also 22AS movements with flat hairspring, from your knowledge? Thank you
The quality of the image on Ranfft is such that it is difficult to compare with the subject watch. Partly because the auto wind mechanism obscures portions of the balance cock. The image appears to include a kind of ”yoke” screwed to the balance cock which surrounds the regulator index which yours doesn’t have. Again, the Ranfft image is such that it is next to impossible to ascertain that the movement actually has a Breguet hairspring. I don’t think it does, actually. As great a resource as the Ranfft archive is, it seems that there are often some inconsistencies in the information provided. It is not uncommon for manufacturers of watches to build several levels of finish in the same calibre of movement.
Yes, I believe that the caliber 22AS can be found with either a flat hairspring or a hairspring with a Breguet overcoil. Looking at the photos below, you can see that the triangular hairspring stud of (1) is farther from the balance wheel pivot than it is on (2). This suggests to me that (1) has a flat hairspring and (2) has a Breguet overcoil. Further below is an illustration (3) from a 1949 Longines service manual that shows the difference more clearly. (1) Source: https://www.ebay.com/itm/174021373146Purchases made through these links may earn this site a commission from the eBay Partner Network (2) Source: https://www.wristlabs.store/product-page/longines-cal-22as-stepcase-automatic-movement (3) Source: @DirtyDozen12
yes, thank you, Canuck and DirtyDozen12, it is clear to me know this movement was done in 2 versions. Very attentive answers, thank you very much!
