One of the standard movements from the german Bidlingmaier GmbH from Schwäbisch Gmünd, was the Bifora 934 with a diameter of 9 3⁄4 lignes (hence the caliber number), an pallet lever movement with a pillar construction.
Its construction is classical and simple: The balance (here in its best version as glucydur screw balance), which is beared in two inhose Bishock shock protection systems, controls a conventional pallet lever movement, which contains a decentral second at “6”.
The hairspring is fix connected to the balance cock and regulated in its effective length by a long regulator arm with scale.
The gear construction is classical-conventional with escapement wheel, fourth wheel, third wheel and minute wheel.
The latter gets its energy from the mainspring barrel, which contains its click spring on the dial side.
On the side view, you see the pillar construction, which was cheaper than using massive plates, but results in a larger thickness.
On the dial side, there’s the rocking bar winding mechanism and the click spring, which is very well made. You also see the rather large bearing rubies.
Timegrapher resultThe specimen shown here, was completely gummed and cleaned and olied afterwards. Nevertheless, the timegrapher outputs are very unsteady, especially in the vertical positions. And there, the positions "12 up" and "9 up" are pretty worse; the reasons can be a badly poised balance or a bent balance staff.
|dial up||+45 s/d|
|dial down||+50 s/d|
|crown right (12 up)||-240 s/d|
|crown up (3 up)||-120 s/d|
|crown left (6 up)||+6 s/d|
|crown down (9 up)||-240 s/d|
|Number of jewels:||17|
Glucydur screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||pillar construction|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||4 hole(s)|
|Functions:||hour, minute, decentral second|
|Size:||9 3/4''' (measured: 21,0mm)|
|Production period:||1946 - 1958|
Flume: 1957 35|