Bifora 114

 
Bifora 114

Bifora 114

Description

In 1958, the pretty modern built Bifora debuted, a 11 1/2 ligne selfwinding movement with twin pawl changer.

base plate

base plate

The base plate shows the good execution of this movement, all important bearings contain rubies and even the center minute wheel is ruby-beared.

base plate with center minute wheel

base plate with center minute wheel

As usual in the 1950s, this movement uses a directly driven center minute wheel, beared under an own cock.

gear train

gear train

The remaining gear train is typical for a movement with directly driven center seconds indication: Third wheel, center seconds wheel and finally the filigree steel escape wheel.

side view of the gear train

side view of the gear train

Unlike later movements, this is a massive and not a pillar construction.

As balance, a modern screw-less anular balance is used, which is beared in two inhouse Bishock shock-protecting bearings.

It beats contemporarily slow with 18000 A/h can be adjusted only directly at the hairspring key. In return, it already uses a moveable stud to minimize the beat error.

mainspring barrel bearing

mainspring barrel bearing

Even the upper mainspring barrel bearing has got a ruby, but probably only for the reason to reach the well-marketable number of 21 jewels.

selfwinding mechanism missing

selfwinding mechanism missing

You can see here the two brass bearings for the two pawl changer gears and the ruby bearings for the reduction wheel, which engages with the crown wheel.

lower side of the selfwinding mechanism

lower side of the selfwinding mechanism

The selfwinding mechanism consists of only three parts, two identical pawl changer gears, whose inner/lower gear engages with the reduction wheel. This meams, both turn their inner part always in the same direction.

In this video, you see the winding by the oscillating weight and how regardless of its turning direction (and thus the turning direction of the upper pawl changer wheel) always one of the two gears spins freely, while the other one transmits the power.

selfwinding gear train

selfwinding gear train

Since the two outer sprockets of the ratchet changer also mesh with each other stationary, i.e. both wheels turning in opposite directions, it is clear that the pawls on the pawl changer wheels ensure that they is always one wheel idling while the other is transmitting the power.

On manual wind, both gears spin freely and detatch the oscillating weight.

lower side of the pawl changer wheels

lower side of the pawl changer wheels

On the lower side of the pawl changer wheel, you can see the riveted axle, which bears the pawl on the upper side of the wheel.

selfwinding mechanism

selfwinding mechanism

It is noteable, that both wheel are beared on one side only, the upper side is held in place only by the cover between position 7 and 10 o’clock.

inside the oscillating wheel

inside the oscillating wheel

The oscillating weight, which engages only with the upper pawl changer wheel, is ruby beared.

Bifora 114: Dial side

Bifora 114: Dial side

Since the Bifora 114 does not have a date indication, the dial side looks pretty clean. On the left there’s in inhouse Bishock bearing, on the right the yoke winding system.

In the lab

This movement came as a movement without case into the archive and got a simple service.
Except one value with a large deviation, whose cause is unknown, the rates are quite satisfactory.

Timegrapher result



horizontal positions
dial up -9 s/d 215° 0.2ms
dial down -7 s/d 252° 0.3ms
vertical positions
crown right (12 up) -46 s/d 159° 0.7ms
crown up (3 up) +-0 s/d 211° 0.8ms
crown left (6 up) +12 s/d 222° 0.4ms
crown down (9 up) +29 s/d 178° 0.1ms

Technical data

Manufacturer:Bifora
Caliber:114
Size:11 1/2''' (measured: 25,7mm)
A/h:18000
Number of jewels:21
Escapement:Pallet lever
Balance types: Nickel anular balance (two legs)
Shock protection(s): Bidlingmaier (Bifora)
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel
  • center minute wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:2 hole(s)
Features:
  • SCD (direct center seconds)
  • AUT (selfwinding)
References: Flume: K3 228
Production years:1958-1965
Inventory number:22013

Usage gallery

Bifora gents watch  (case missing)

Bifora gents watch (case missing)

This movement is kind donation to the movement archive