Which bicycle component did Tullio Campagnolo patent in 1930?

Tullio Campagnolo patented the quick-release skewer in 1930.

The quick-release skewer lets a rider secure or remove a bicycle wheel without using a separate wrench. Campagnolo developed the mechanism after encountering difficulty removing a wheel during a race in cold, snowy conditions.

His invention used a cam-operated lever to clamp the wheel securely in the fork or frame. The design made wheel changes faster and became a standard feature on many road bicycles, especially before thru-axles became widespread.

Campagnolo later built a major Italian component company known for derailleurs, cranksets, hubs, and complete groupsets. The quick-release is sometimes confused with the derailleur, but Campagnolo’s early landmark patent concerned wheel retention and removal rather than gear shifting.