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.
Escapement wheel, fourth- and third wheel have get bearing jewels, 1948 this was an indicator for better movements.
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.
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.
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
Timegrapher resultThe 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:<br/> The rates nearly showed the limits of the timegrapher and the movement cries for a service!
|dial up||+-450 s/d||126°||2.6ms|
|dial down||+24 s/d||230°||0.6ms|
|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|
|Number of jewels:||15|
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:||3 hole(s)|
|Functions:||hour, minute, decentral second|
|Size:||8 3/4 x 12''' (measured: 19.9 x 26.4mm)|
Flume: 1952 36|