Handling time

How do we interact with the technical objects that are part of our everyday lives? Opening a car door, turning on the light, adjusting the flow and temperature of the shower, unlocking a mobile phone – we turn, push, press, pull and touch, often without a second thought. The relationship between human and machine, hand and tool, mind and technology, are rich and complex, yet rarely discussed. The most perfectly ergonomic objects are almost invisible, seamlessly becoming extensions of our bodies. This is the achievement of countless engineers who strive daily to create systems so natural and fluid that we forget their complexity.

For a mechanical watch, this question is especially crucial. The object is small, its inner workings extremely delicate, and its limited energy is drawn from our movements. In many ways, a watch is like a living organism, dependent on us to function.

Winding the mechanism, setting the time and date, activating the chronograph – all these actions require direct  interaction with the watch’s mechanics. Watchmakers know that even the slightest mishap can damage the heart of the timepiece. Over centuries, they have designed and refined ever more ergonomic solutions, seeking to minimise risk while balancing protection and accessibility – a near impossible challenge.

Prior to the advent of water-resistant and shock-resistant watches in the 20th century, users  had to assume the role of watchmaker. Winding the mechanism meant opening the case, inserting a tiny key, and turning it with care. Sometimes, a tiny wooden stick was needed to push a lever inside the movement. Watches were strictly shielded from water and humidity, and the slightest shock could break the balance staff.

Industrialisation changed everything. While the mechanism remains delicate, it is now better protected. Yet new challenges arise: how to turn a crown without compromising water resistance? How to easily set the date, day, month and moon phase of a perpetual calendar? Innovations continue to flourish, and Audemars Piguet is at the forefront of this ongoing quest for ergonomic excellence.

With Europe’s industrialisation in the 19th century, watches became indispensable companions of modern life. Yet winding keys proved increasingly problematic. Replacing them with a crown might seem straightforward, but to implement this idea, watchmakers had to invent additional mechanisms capable of controlling two distinct functions: winding and setting the time.

For a time, two systems coexisted. The technically simpler was the “push-piece” winding mechanism, which combined a crown and a small push-piece beside it. To wind the watch, the user simply turned the crown; to set the time, one pressed the push-piece while turning the crown.

More ergonomic was the “pull-piece” winding system, which concentrated all functions within the crown. As its name suggests, the user simply pulled the crown out to switch from one function to another. Though more complex to manufacture than the push-piece system, it took longer to become widespread.

The most significant inventions emerged in the first half of the 19th century. Among the many watchmakers involved were John Roger Arnold (1820) and the Breguet workshops (1830). The Vallée de Joux played an active role, notably with Hector Audemars’ system in 1838 and those of Adolphe Nicole and Antoine LeCoultre in 1846 and 1847, respectively.

However, the inventor who had the greatest impact on the development of the winding crown (then called the “knob”) was Frenchman Adrien Philippe. In his book Les Montres sans clé (Watches without Keys), published in 1863, he recounts seeing a crown-wound watch made by Louis Audemars in 1842. Fascinated, Philippe developed his own pull-out  winding system – a mechanism so sophisticated that it caught the attention of Antoine Norbert de Patek, leading to the formation of Patek Philippe.

Pressing a button to activate a function – a simple gesture that connects human to machine. Whether calling a lift, turning on a light, opening the cover of a pocket watch, this intuitive interaction is central to our daily lives. In watchmaking, this button is known as the push-piece, a component that comes in many forms and activates a wide range of functions.

On early chiming pocket watches, the chime was often triggered by pressing firmly on the bow or by pressing a semi-rotational knob set within it (see illustrations). Additional push-pieces on case sides allowed users to adjust the date, moon phase, or time zones.

But it was with the advent of the chronograph that the push-piece truly came into its own. The first monopoussoir (single-push-piece) mechanisms used one button to successively start, stop and reset the chronograph. In the 20th century, a second push-piece was introduced – one to start and stop, the other to reset – marking a new era in functional design.

Push-pieces vary in form and function – sometimes integrated into the crown for discretion, sometimes oversized to assert their presence. Their design balances utility with aesthetics.

Depending on the function they trigger, push-pieces require varying degrees of energy. The user-friendliness is integral to horological excellence. The force required to activate them, the smoothness of their movement, their travel (depth), dimensions, surface finish, and synchronisation with the movement – all are critical indicators of quality.

Their vulnerability, however, should not be overlooked. A shock to a push-piece or crown can spread to the heart of the mechanism and cause serious damage. To mitigate this, some watches feature protective guards, designed to absorb impact while preserving access. In some models, these guards swivel to fully cover the push-pieces, ensuring optimal protection.

The more functions a watch has, the more activation and adjustment elements it requires. So how can aesthetic harmony be preserved? How can the case remain free of visible push-pieces, crowns and levers? Watchmakers understood early on the importance of arranging these mechanisms according to their frequency of use. The secret to true ergonomics is in making rarely used components discreet – without compromising ease of access.

To open the cover of a pocket watch, watchmakers almost always placed a push-piece within the crown-integrated bow. However, chronograph pocket watches often used that same position to activate the chronograph. So, what happens when a pocket watch serves both purposes?

Should a separate push-piece be added, at the risk of having to redesign the entire watch mechanism? Or should both functions be combined in the same place, without the act of opening of the cover inadvertently triggering the chronograph?

This short chapter explores a few ingenious solutions found in select timepieces from the Audemars Piguet Heritage Collection. These technical innovations showcase he boundless creativity of watchmakers – masters of reconciling complexity with elegance. 

Water resistance is not the only challenge posed by crowns and push-pieces. Another critical concern for watchmakers is untimely adjustments – interventions made while delicate mechanical operations are underway. These can cause serious damage to the movement.

For instance, setting the date on a 1920s calendar watch while a tiny pin is actively advancing the date or moon phase forward can easily break the mechanism. Over the past half-century, systems have become more secure, but caution remains essential. The golden rule: never force a corrector. If it resists, it’s not the right moment to operate it.

In the absence of a user manual, a simple method is to turn the hands through a full 24-hour cycle and observe when the indications change. Then, make adjustments at the opposite time, so if the date jumps at 23:45, it is safest to use the corrector around midday.

Another forbidden adjustment is setting the time on a minute repeater while it is chiming. This can damage key components such as the minute wheel, the beak of the minutes piece, or the striking studs.

But how can users be aware of these golden rules? For striking watches, watchmakers have long relied on the owner’s horological knowledge, the salesperson’s guidance, or careful reading of the instruction manual. Yet, unfortunate mishandlings still occur.

In 2016, Audemars Piguet introduced a unique safety feature: when the watch is chiming, it becomes almost impossible to pull out the crown to set the time. This discreet innovation protects the movement without affecting user experience.

Such safety features are important steps in the quest for ergonomics. They are rarely communicated, barely noticeable to the wearer and yet essential. As in other fields, ergonomics only becomes noticeable when it is lacking. A well-designed chair moulds itself to the shape of the body so seamlessly that one forgets it is there. The same is true of a well-designed watch.

Since its invention in the 19th century, the chronograph has undergone numerous technical developments – split-seconds hands, jumping seconds, column wheels, cams, vertical clutches, flyback functions, selfwinding systems and laptimers. Each innovation has enriched this emblematic complication.

However, one element remained unchanged: the reset function. The force and precision required to return all hands to 12 o'clock in a fraction of a second is colossal – especially considering the scale. Patented by Adolphe Nicole in 1844, the traditional system relies on a hammer striking a heart-shaped cam, instantly rotating it back to zero when the push-piece is pressed.

In the late 2010s, Audemars Piguet began to rethink the push-piece itself: could it be smaller, more sensitive – like a smartphone button? In short, more ergonomic. One conclusion quickly became clear - the system inherited from Nicole needed a complete reimagining.

On the Royal Oak “Jumbo” Selfwinding Flying Tourbillon Extra-Thin Chronograph RD#5, the reset mechanism works differently. Behind the low-travel, low-force push-pieces winds a small spring that tightens as the chronograph hands advance. When the push-piece is pressed, the stored energy is released, instantly resetting the hands – without requiring additional force. Imagine a child on a swing. Once pulled back, he or she will swing forward effortlessly when released. This new chronograph works in the same way – energy is stored in advance and then released at the right moment.

Smaller, more responsive and requiring less force, the new push-piece marks a major leap forward. What might seem like a minor refinement, is, in fact, a major innovation –  one that opens a new chapter in the history of the chronograph.