In detail: What makes the crown of the Cronus Protoyp 2 so special?

By Montredo in Lifestyle
March 4, 2021
In detail: What makes the crown of the Cronus Protoyp 2 so special?

Those who read us regularly will already be familiar with Cronus. The watch brand was launched only in 2015 by product designer Juri Schob and has since successfully launched three collections within a short period of time: Prototype 1,2 and 3. (You can read the full article here: Cronus: Innovative dive watches “Made in Germany“.)

One aspect that we touched on in our first article, but by no means explored in all its facets, is the patented crown mechanism of the Prototype 2 series. Schob filed an according patent application in 2013 already, even before it was ready for the market, and today it represents a major USP of Cronus. Reason enough for us to take a closer look at this in-house development.

The Cronus Prototype 2

A brief review of the Prototype 2

The inspiration for the Prototype 2 collection was an old Russian diving watch made by AGAT, the “191 CHS” model to be exact, which was once the first choice for USSR Navy divers due to its extreme dimensions. Thanks to a crown that protruded far out, it withstood extreme water pressures of up to 700m deep, while being able to be operated with diving gloves on.

Schob liked the watch, but wanted to develop it further. The basic idea was as follows: To develop a specially locked crown protection mechanism that would be durable on the one hand and easy to operate on the other. It goes without saying that the intricate inner mechanics must be protected from possible water penetration as well as possible, too.

Identifying the problem

Of course there are diving watches with a wide variety of crown locking mechanisms from other manufacturers as well. In Schob’s eyes, however, there was none that would provide sufficient protection for extreme diving watches without having a downside. So, as a first step, he identified a number of problems that most diver’s watches hold, and then subsequently a way in which the new crown mechanism could eliminate them.

Prototype 2 with black PVD coating

Above all, the relatively long “unscrewing” time of the crown was a thorn in his side. This not only costs time, but in the long run is also associated with locking, which makes revisions unavoidable. In addition, inadequate tightening of the crown harbors further dangers, as too strong tightening damages the seal in the long run, while too lax tightening no longer guarantees 100% water resistance.

Solution to the problem

Schob succeeded in developing a winding crown that is constantly pressed against the case with the help of a protective device, guaranteeing water resistance up to 300m or 30 bar without any problems.

The principle is as efficient as it is convenient for the user: The crown can be accessed or made more operable by means of a slide that moves back and forth between two positions. Only when the crown is “unlocked” can one pull the crown out. Once you’ve set the time correctly, all you have to do is flip the slider back over to securely lock the crown. This has the great advantage of eliminating the need to touch the crown after setting the correct time, which can sometimes move the minute hand with other watches.

The elimination of a screw mechanism also prevents material fatigue, which means that a damaged rubber seal will need to be replaced far less frequently. Due to the predefined position of the slider, the pressure on the crown/seal is always constant, resulting in longevity.

Schob also relies on a visual signal effect for the Prototype 2 watches: When the crown is open and ready for use, a red signal circle protrudes from the safety bar. Only when the crown is correctly closed does it disappear again. Finally, a Control Before Dive lettering on the dial reminds the wearer to flip the locking lever again before taking a dip (or shower).

Red = Danger

Cronus watches at Montredo

With his German-made watches, Juri Schob shows that it doesn’t always have to be a Grande Complication to make a watch special. Sometimes a good idea that pays tribute to an existing mechanism while making it even better is enough.

If you have a soft spot for Cronus’ Protoyp 2 watches, you can find them directly in our store. See here for our large selection of Cronus watches.

The vintage variant can be artificially aged by a special process if desired.

By the way: If the description wasn’t technical enough for you, we recommend a visit to the German Patent and Trademark Office for more interesting insights.


This is a sponsored article by Montredo for Cronus.


Previous comments (1)

  1. Very interesting, never heard about Cronus before.
    My pick would be the Prototype 3 though.

    March 10, 2021

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