Switzerland · Swiss patents granted 15 May 1949 and 31 December 1951; the balance entered production use from 1952
Gyromax Adjustable-Inertia Balance
Partially verifiedThe Gyromax became a hallmark of Patek Philippe's precision regulating organs and directly influenced later adjustable-inertia balance designs used across the industry, including Rolex's own Microstella system.
The Gyromax balance replaces the traditional timing screws projecting from the rim of a balance wheel with small turnable eccentric weights (collets) recessed into the rim itself, allowing both poise and rate adjustment without external projecting screws.
Because the balance carries no separate regulator acting on the balance spring, it is a free-sprung design, avoiding the small timing inconsistencies that a moving regulator index can introduce.
How to verify this yourself
Confirm the two cited Swiss grant dates (1949 and 1951) directly against the Swiss Federal Institute of Intellectual Property's historical patent register under Patek Philippe's name before citing a specific patent number, since secondary sources vary in how precisely they specify each filing.
Manufacturers known to have used it
- Patek Philippe
Sources & references
- Patek Philippe, published technical history of the Gyromax balance
- Perez, C., 'A Perfect Circle', TimeZone (2003), historical survey of adjustable-inertia balance design
Where sources disagree, the disagreement is stated rather than resolved silently.