The Mystery Behind the Gyromax Balance

In 1947 Patek Philippe applied for a patent of a new balance. It was granted in 1948*.



The company called the new device the Gyromax balance and began installing it in many watches. The main advantage of it was that a watch could be poised easier and could be adjusted for time without hairspring’s regulator (which does contribute to small irregularities). Watches without a regulator are called free sprung. Almost all marine chronometers are free sprung.

The company fitted them into all kinds of models. Here is one of them, a perpetual calendar, Ref. 3940 from 1980’s.



The claimed invention was based on small friction-tight discs placed on the periphery of the balance. They were slotted, and therefore springy, and fitted tightly over small pins fixed vertically to the balance. By revolving them it was easy to regulate the poise and the mean time. There is no doubt it was a substantial improvement.


A close up of a balance


And a close up of its disc


Patek Philippe’s add from 1963. It reads:

"The Gyromax Balance, developed in the Patek Philippe Laboratory for Advanced Research, is the outstanding horological achievement of modern times. It permits the most precise and enduring regulation of a watch ever achieved, making the old-fashioned index regulator obsolete and eliminating the need for periodic readjustment.
The Gyromax is only one of the elements and only one of the exclusive patents which make Patek Philippe the world’s foremost watch.
PATEK PHILIPPE
CRAFTSMEN OF PERFECTION”

As long as the patent lasted Patek Philippe was the only company making watches with the new improved balance. Or was it?

Below is a close up of the balance from an American Edward Howard model made circa 1912.




And a close up of its regulating organ:

Doesn’t it remind you of something?

And the device was even patented



by one Joseph Alexander Freund of Manhattan, New York, on April 25, 1905.**

Free-sprung, Edward Howard with sapphire banking pins and Gyromax-type balance was a remarkable watch, ahead of its time. Unfortunately, only about 300 of them were made.

It is a little known fact that an American idea, 40 years later, found its way into complicated Swiss wristwatches. Freund, its inventor, did not live to see his invention reinvented, he died in 1944, four years before.

Philip Poniz


* The same year (1948) the company applied for an improvement in its design which was granted in 1951.
**Two years later Freund obtained a patent (No. 862,465) for an improved “toothed” version of the discs.

 

Hi Marty,

In case of Gyromax balance the collets are of the same metal as the balance, that is Glucydur, which is a Beryllium copper alloy.

A balance spring regulator has a few inherent faults, of which the most problematic is that there has to be some space between the regulator pins and the spring.



Otherwise, the pins will drag the spring with them. In large amplitudes, the spring, most of the time, will lean against one pin or the other. But in small amplitudes it will not. In an extreme case, at a very small amplitude, it might actually not touch the pins at all. Therefore, the point of the effective outer attachment is a function of the amplitude, in other words, the regulator can make the spring longer or shorter by itself, which, of course, affects the rate. There has been all kinds of patents to fix the problem, such as in the photo below, but none have been used commercially.



In case of a flat spring, the second coil, in large amplitudes, can touch the inner pin, affecting the rate.

Additionally, the regulator “moves” with the temperature changes, with the increase, the arm becomes longer and the pins embrace the spring tighter.

There is no doubt that an average owner, who can adjust his/her watch with a regulator, cannot fix it with mean-time screws, or collets in case it has a Gyromax balance.

I hope we will continue a discussion of horological patent infringements. I know about a dozen of such and I hope to hear more about them.


Philip

 

I just found a Patek Philippe Gyromax balance even more strikingly similar to Edward Haward's:

Patek Philippe Cal. 13.5-320 Edward Howard No. 248, circa 1912
made in 1965