The Tissot 2401, which was produced in the early/mid 1970ies, was probably one of the latest inhouse Tissot movements.
It is a typical ladies’ watch form movement of tiny size and is construced like any other movement of that type. Nevertheless, there’s one thing, which distinguishes it, that’s its fast beating movement, which uses 28000 A/h instead of the common 18000 or 21600 A/h.
Because of this, the precision was enhanced and since the balance had to be smaller and with less weight, the watch was less affectable by external influences and shocks.
The balance is secured in two Incabloc shock protections and controls a conventional pallet lever movement.Video on YouTube
On the dial side, you can spot the escapement wheel with its unusual many teeth - that’s due to the fast beating number.
|Number of jewels:||17|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Size:||5 3/4 x 6 3/4''' (measured: 15,3 x 18,0mm)|
Flume: K3 N1 -|