Long before Oris was relaunched as “High Mech” company, there were one of the most interesting manufacturers of pin lever movement, with a bandwidth ranging from simple pillar constructions up to officially certified pin lever chronometers. The Oris 158 is from the entry range, but at least offers an interesting kind of shock protection.Video on YouTube
The construction of this movement, which is built as a pillar construction, is pretty standard: The high building mainspring barrel directly drives the center minute hand and this gear drives third wheel, fourth wheel and escapement wheel. The balance beats with 18000 A/h and can be adjusted by a long regulator arm. The hairspring key is less precise, since the distance between the two pins is very large.
The high building mainspring barrel contains a larger mainspring, which leads to longer power reserve and an increased precision.
At “4:30”, you see the U-shape of the lever bearing. A watchmaker can bend it to achive an optimal depthing for the lever pins.
The Oris 158 has got an axial shock absorber, which protects the axle of the three-leg balance against vertical shocks. It works with moveable cap jewels for the balance bearings.
Lateral shocks cannot be absorbed at all, and so in literature, these mechanisms are called partial shock absorbers.
The macro photos show the bordered cap jewel of the upper escapement bearing. It is held in position by a fork spring, whose one ending is connected to the long regulator arm.
On the dial side, there’s a similar mechanism: Here, a non-bordered cap jewel is held in position by a spring with two holes, so that it can be moved up and down on axial shocks.
At “9”, you see the balance bearing with dismounted cap jewel. The cap jewel is put into the hollow on the plate and kept in position by a spring.
On the dial side you see the rocking bar winding mechanism, whose spring is also used as click spring. The click mechanism is quite well made for such a simple pin lever movement.
|Number of jewels:||2|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||pillar construction|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||6 hole(s)|
|Size:||10 1/2''' (measured: 23,8mm)|
Flume: 1947 89|