Osco 42

 
Osco 42 | 17jewels.info - The Movement Archive

Osco 42

Description

One of the first Osco-movements, which Osco, born in 1948, shortly after the end of WW II, launched, was the form movement Osco 42 with a size of 8 3/4 x 12 lignes.

A characteristical feature of this pillar-constructed movement is its single bridge construction, which bears all gears, starting with the mainspring barrel, and finishing with the escapement wheel.

Osco 42: base plate

base plate

Escapement wheel, fourth- and third wheel have get bearing jewels, 1948 this was an indicator for better movements.

Osco 42: gear train

gear train

The gear train has got a classical linear (one-storey) construction, at that time, this was standard. You can see, how much space was unused.

Osco 42: side view of the gear train

side view of the gear train

A speciality of the specimen shown here is the gold-toned Glucydur screw balance. It doesn’t neccessiarily fit the rather simple pillar construction and the lack of a shock protection. To find such a movement in running condition (more or less, as the timegrapher will tell later), is not easy.

Osco 42: Osco 42 dial side

Osco 42 dial side

The dial side mets the expectations - for the winding system, a rocking bar mechanism has to be sufficient, and the click is nothing but a simple wire spring. Somewhere costs had to be reduced in 1948.

In the lab

The specimen shown here was gummed and came without winding stem into the the lab. Das hier gezeigte Werk kam ohne Aufzugswelle ins Labor und war verharzt. Since it had to be made viable only for documentation purposes, only a simple cleaning was done, which would not have been sufficient for daily use.

Timegrapher result

The visually very pleasing Glucydur screw balance deceives a bit about the bad timegrapher results. For fairness one must say, that the rates would have been much better after a real service. Without that, the specimen tell about long and hard use:
The rates nearly showed the limits of the timegrapher and the movement cries for a service!

horizontal positions
dial up +-450 s/d 126° 2.6ms
dial down +24 s/d 230° 0.6ms
vertical positions
crown right (12 up) +250 s/d 154° 2.6ms
crown up (3 up) +600 s/d 150° 2.6ms
crown left (6 up) -400 s/d 125° 2.1ms
crown down (9 up) -550 s/d 147° 2.0ms

Technical data

Manufacturer:Osco
Caliber:42
Size:8 3/4 x 12''' (measured: 19.9 x 26.4mm)
A/h:18000
Number of jewels:15
Escapement:Pallet lever
Balance types: Glucydur screw balance
Shock protection(s): none
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel, center minute wheel, mainspring barrel
Construction type:pillar construction
Winding mechanism:rocking bar winding system
Setting lever spring:3 hole(s)
Features:
  • s (decentral seconds)
References: Flume: 1952 36
Inventory number:17003

Usage gallery

Osco 42: Ankra gents watch  (with non-matching stem)

Ankra gents watch (with non-matching stem)