Waltham 750-B

Description

The 7 1/2 ligne Waltham 750-B (also known as Waltham 767) is a very high-quality executed American movement from around 1940.

To achieve the then-high number of 17 jewels, even the minute wheel runs in two ruby ​​bearings.

The tonneau-shaped design allows for a particularly large mainspring barrel and thus simultaneously a long power reserve with good accuracy.

The gear train is of conventional design, with a directly driven central minute wheel, third wheel, decentral seconds wheel at 6 o’clock, and finally a steel escape wheel into which the Swiss-made pallet anchor engages.

The execution of the bridges with their chamfered edges is also very beautiful.

The balance wheel is a gold-colored Glucydur screw balance, where the actual use of poisting screw are still clearly visible. Of course, it doesn’t yet have shock protection.

Even though the regulator indicator and hairspring key are missing on this particular example, it’s clear that the balance spring has a (Breguet) terminal curve, which ensures, that the 18,000 A/h of this movement can be achieved with exceptional precision.

On the dial side, the yoke winding mechanism with its very robust designed setting lever spring immediately catches the eye, as does a detail that one usually only finds in American movements: The two banking pins for the lever are adjustable, so that the engagement depth of the pallets can be corrected.

Technical data

Usage gallery