A patent in watchmaking is not merely legal protection: it is the documented trace of a technical problem solved. Dietrich Gruen understood its value in 1874, when he filed the Safety Pinion to protect the gear train from mainspring breakage. Since then, the patent has become the instrument through which manufacturers establish — and defend — every qualitative leap in mechanics.
The recurring problems that have generated patents are few, but profound: shock resistance, balance wheel precision, case sealing, energy management, acoustics. Wyler patented in 1927 the Incaflex balance wheel, an elastic structure capable of absorbing shocks without losing oscillation regularity; he demonstrated it publicly by dropping a watch from the Eiffel Tower in 1931. Four years before shock absorbers became an industry standard. The resonance between two independent balance wheels, a phenomenon described by Huygens in 1665, waited until 2016 to find a patentable solution wearable on the wrist: Armin Strom's Resonance Clutch Spring, miniaturized by Claude Greisler, synchronizes the two oscillators through a spring that manages energy transfer without rigid contact.
Some patents concern materials. A. Lange & Söhne developed in 2010 the Honey Gold, a secret and patented golden alloy more resistant than standard gold, with a hardness that reduces deformations over time. De Bethune patented the flat terminal curve of the oscillating spring and moonphase discs in steel and palladium, with an error of one day every 122 years. Other patents solve case problems: Rolex's Ringlock system enables sealing up to 11,000 meters, while De Bethune's floating lugs allow the case to adapt to the wrist independently of strap rigidity.
A patent can also concern the human-machine interface. Leica's push-crown system, developed by Reinhard Meis, former Lange, accomplishes three simultaneous operations with a single press: stops the movement, resets the seconds, activates the status indicator. Rolex in patent EP4632499A1 solved the problem of instant triple calendar with a secondary spring that accumulates energy and releases day, month, and date in sync with a single action, reducing friction and energy consumption compared to traditional systems.
A patent expires. The Horwitt design for the Museum Watch, filed in 1958, was already in the public domain by 1972. Breguet's tourbillon, patented in 1801, is today accessible to anyone. Patent expiration is the moment when a technical solution ceases to be the property of one and becomes the heritage of the craft.