Osco 1065

 
Osco 1065

Osco 1065

Description

Osco (Otto Schlund) in Schwenningen was one of the large ebauche factories in Germany, which was especially important in the cooperation “Parat”. However, there was only one single series of selfwinding movements, which consts of only two members, the caliber 1064 and the caliber 1065 without date indication, shown here.

Both movements base on the manual wind movement Osco 1060.

base plate

base plate

As you can see on the image, the base plate was enlarged for the oscillating weight to a diameter of 11 12 lignes.

minute wheel cock

minute wheel cock

The gear train is fully beared in ruby bearings and has got a contemporary construction with a central and directly drive minute wheel, located under its own cock, and a directly driven center second.

gear train

gear train

The two-storey construction is space-saving, you can see, that large parts of the massive base plate are not covered by wheels.

side view of the gear train

side view of the gear train

The Osco 1065 has got a screw balance with two long, slightly curved legs, which beats with 18000 A/h and is normally beared in two Rufarex Shock protection bearings. But there are exceptions, the specimen shown here uses a pair of Rufasuper bearings, which at least visually remind a bit of Incabloc shock protections.

Rufasuper shock protection

Rufasuper shock protection

The selfwinding mechanism consists of an axle beared oscillating weight, which drives the crown wheel with a rocking bar and two reduction wheels. The first reduction wheel is interfered by a pawl to avoid running out.

selfwinding mechanism

selfwinding mechanism

The second, large reduction wheel has got a commutator clutch on its lower side, which decouples the selfwinding gears on manual wind.

reduction wheel with commutator clutch

reduction wheel with commutator clutch

This mechanism is as simple as genious!

The complete selfwinding module can be released from the movement; all bearings contain rubies.

selfwinding module, top

selfwinding module, top

The oscillating weight is axle beared.

inside of the oscillating weight

inside of the oscillating weight

As long as the selfwinding module is not mounted, you can see the relationship to the Osco 1060, the two biggest diferences is the larger diameter of the base plate and the additional bearing next to the crown wheel for connection of the selfwinding mechanism.

Osco 1065 without selfwinding module

Osco 1065 without selfwinding module

A final image with mounted selfwinding module, but missing oscillating weight:

movement without oscillating weight

movement without oscillating weight

On the dial side, you can see the yoke winding system and the closed exchange wheel for driving the hour wheel. On the bevelled edge, there’s space for a date ring, but this is only available onn the Osco 1064.

Osco 1065 dial side

Osco 1065 dial side

In the lab

The specimen shown here has got lots of problems, a scratched dial and missing hands, when it came into the lab. Among the problems, there’s a missing ruby inset of the upper Rufasuper bearing, a floating ruby and a shortened axle of the center second arbour. Because of all these problems and the lack of spare parts, a repair was not possible.

Technical data

Manufacturer:Osco
Caliber:1065
Number of jewels:25
Escapement:Pallet lever
Balance types: Nickel screw balance
Shock protection(s): Rufasuper old
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
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:1 hole(s)
Features:SCD,AUT
Functions:hour, minute, second, selfwinding
A/h:18000
Size:11 1/2'''
Literature: Flume: 1962 74

Usage gallery

Stowa gents watch  (incomplete)

Stowa gents watch (incomplete)