Bifora 55

 
Bifora 55 | 17jewels.info - The Movement Archive

Bifora 55

Description

Die 5 1/4 ligne Bifora 55 is an early ladies' form watch movement from Bifora.

It sill has got the classical design with partially angeled bridges, a scale on the balance cock and a stripes decoration.

Bifora 55: base plate

base plate

The base plate is massive and has got the typical construction of small form movement where the gears and bearings partially overlap each other.

Of course, all bearings, except those of the minute wheel, contain rubies. In some models the minute wheel has got ruby bearings, too.

Bifora 55: gear train

gear train

This movement has got really small third and fourth wheels, the third wheel has got a very long axle. That is not very watchmaker-friendly, but there’s no other way due to the limited space.

The large escapement wheel partially runs below the fourth wheel bearing, so, it’s the two-storey construction, which is typical for that kind of movements.

Bifora 55: side view of the gear train

side view of the gear train

The screw balance is not shock protected and beats with 18000 A/h. The minute wheel is directly driven by the mainspring barrel.

Bifora 55: Bifora 55 dial side

Bifora 55 dial side

On the dial side, there are no surprises, but you still find the yoke winding system, which Bifora pared down in later movements in favor of the cheaper rocket bar winding system.

In the lab

Unfortunately, the specimen shown here is not shock protected and so suffers of a broken balance staff. Hence no service and regulation was made.

Technical data

Manufacturer:Bifora
Caliber:55
Size:5 1/4 x 8 1/2''' (measured: 12,8 x 19,3mm)
A/h:18000
lift angle:51.5°
Number of jewels:15/17
Escapement:Pallet lever
Balance types: Nickel screw balance
Shock protection(s): none
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
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)
References: Flume: 1952 32
Production years:1934-1953

Usage gallery

Bifora 55: Bifora Ancre ladies' watch

Bifora Ancre ladies' watch

Many thanks go to Mr. Keilhammer for the donation of that movement!