Buckling spring
Provided by the ASK Keyboard Dictionary
Buckling springs (B/S) are keyboard key-switches that characteristically buckle into a kink instead of compressing in a straight column. The term most often describes IBM's famous buckling springs switches designed by Richard Hunter Harris. Buckling springs allow a key-switch to provide actuation, tactility, auditory feedback and a keycap return force all with just one spring.
