The Bulova 5 BD is an extraordinarily well made ladies’ watch form movement, which debuted around 1970. It impresses not only by its glossy golden-toned finish, but also by the number of used jewels: 23 jewels are record-breaking in this class!
The golden-toned Glucydur balance in beared in two KIF Ultraflex shock protection systems. The hairspring is connected to a moveable stud, its effective length can be regulated by the hairspring key only - a solution, which is a bit too simple for such a well made movement.
The (almost) empty main plate shows, that the escapement wheel is beared in a chaton with cap jewel, and that additionally, the mainspring barrel is jewel-beared, too. The latter has not go technical advantage, though.
How well the free space on that movement is used can be seen on the tiny lower boundary of the mainspring barrel. For a watchmaker, this requires exteme caution when clamping the movement for not bending or breaking it!
The gear train bridge also contains three chatons with cap jewels, which means, that the escapement wheel is beared in 4 jewels, fourth and third wheel in three jewels.
On the dial side you see two further chatons with cap jewels - here for the pallet lever and for the escapement wheel. And of course, this movement uses a yoke winding system, but that’s standard for such a fine movement.
|Number of jewels:||23|
Glucydur anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Size:||5 1/2''' (measured: 13,0 x 15,2mm)|
Flume: K3 -|