Compressor system

EPSA Ervin Piquerez compressor patent drawing

The EPSA (super) compressor rediscovered and re-invented A water-resistant watch with two crowns is a (super) compressor watch, right? Not quite. In a way, this could be true for vintage watches, but in fact, not always. And for today, this is even more doubtful, as nearly all double crown & internal bezel watches just use […]

Compressor crown

The original MONOFLEX compressor crown by EPSA, Ervin Piquerez SA, original illustration from an advertisement

The MONOFLEX crown As hinted in our last blog post about the Compressor principle invented and widely used by EPSA for cases of various watch brands of the 1950s and 1960s, also the crowns used in the EPSA cases featured the compressor principle. EPSA called them MONOFLEX crowns and they were an integral part of […]