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.
I have the gyromax in my wristwatch, the PP is way more accurate than my Rolex which is also free sprung.
Philip, were the discs, and the "stubs" on which they sit, required to be of any particular metal? It strikes me that this invention works in principle exactly the same way as the previous screws. I would accept the claim that this made the adjustment process easier (for a Patek technisian) and more accurate, but I don't see it as competing with the regulator ... which I assume was designed for the user of the watch to adjust. I confess that I have never understood the "competition" between regulator and wheel screws, so this would be a good opportunity for you to teach me
Hi Martin, The regulator works by altering the effective length of the balance spring, which introduces small but undesirable variations in its isochronism. This effect is avoided in freesprung designs. The Gyromax adjusting discs also sit down in the thickness of the rim which improves the aerodynamics of it as compared with the traditional screws in the Pennington style balance. Regards, Graham
Yes, I understand what the regulator does, my question is aimed at the reason for using it - which is to speed up or slow down the rate of rotation of the balance wheel. Adjustment of the balance wheel screws (or discs) has inter alia the same effect does it not? By turning a screw or a disc, the centre of gravity of the screw or disc is moved further from or nearer to the centre of the wheel, decreasing or increasing its rate of rotation. Of course screw/disc adjustment also affects the symmetry of the wheel itself (which is what I assume is referred to as "poise"). But I have always considered that the first effect of screw/disc adjustment is (speed of rotation) is the same as that of regulator adjustment. To put that another way, I assume that a watch is sent to a specialist to carry out screw or disc adjustment because the watch is not keeping accurate time, and because just adjusting the regulator is no longer producing the necessary results in accuracy, which in turn is the result of loss of isochronism which you mention. So what is now needed is a combination of adjusting the speed of rotation whilst retaining isochronism.
Hi Martin, Because adjusting the position of the regulator alters its geometry as well as its effective length, by not only changing the length but potentially its mode of engagement with the index pins, the freesprung configuration removes those undesirable variables and allows the spring to 'breathe' without interference as it was designed to. As you know, freesprung watches have historically been amongst the best performing pieces and are usually the highest grades. If a watch is very closely adjusted, allowing the user to alter any of the parameters which the adjuster has so carefully set up just defeats the whole object of their labours. Dynamic poising involves working on the balance and spring as a complete oscillating system, not just treating each element in isolation. Regards, Graham
The way I like to think of it is that the hairspring is an incredibly complex structure with dynamic changes inherent in its function. Modifying it in any way unleashes the gates of hell. In an old style (pre-Guillaume) balance, the compensation screws are fixed to the rim and never adjusted once the balance is brought to compensation. That leaves only the mean time screws available for adjustment of the rate. These must exist in pairs or any adjustment of them will alter the poise of the balance. Even then, the dynamic poise may suffer alteration. The presence of screws at all, also introduces errors from turbulence and other aerodynamic effects. The gyromax must be based on a balance that has all the temperature compensation built into the basic design so that it is invariant with temperature. The only adjustments left are poise and moment of inertia. By having many very small elements extremely fine adjustments may be made for both at the same time. The changes in moment determine the rate and the poising disturbances are adjusted to restore poise. The question for me is how they train people to do that. (Perhaps it is all theory and no one really does it.) I have a hard time thinking of any circumstances in which a gyromax balance would need to be touched in normal operation of a watch equipped with one.
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
The Freund system has several advantages over timing screw adjustment. 1 The adjustment is doable with the balance fully supported reducing the risk of distorting it out of round and flat. 2 The adjustments are visible making it easier to maintain poise 3 If a weight brawls replacing it is easy. Break a screw, and it does happen,you have drill it out 're-tap and realign the balance and then repoise, It vastly improves maintenance. Freesprung versus spring regulations is another topic.
Freund patented the balance independently before he went to work for E. Howard Watch/Keystone. He was a very bright man.
I should have written breaking instead of brawling, If breakage occurs, the disk is more likely to break off. Also, I have seen a Keystone Howard series 10 with a Freund balance.
