Locking means

Ball bearings, rollers, pins, segments, catches or flat slide valves or (push) buttons are mainly used to lock quick couplings. Less common are locking forks, bayonets, screw sleeves, toggle levers or eccentric locker. All these terms describe how an adaptor is fitted to the quick coupling, i.e. locked.

All locking types ultimately serve to securely join the two fitting halves against the separation forces which increase in proportion to the line pressure. The ball locking has established itself as a standard in industrial applications, accordingly roller or pin locking mechanisms are rather rare. Other locking mechanisms like catch locking are only used in special cases (e.g. high-temperature coupling).