Switchblade

A switchblade (also known as switch knife, automatic knife, pushbutton knife, ejector knife, flick knife, gravity knife, flick blade, or spring knife) is a pocketknife with a sliding or pivoting blade contained in the handle which is extended automatically by a spring when a button, lever, or switch on the handle or bolster is activated. Virtually all switchblades incorporate a locking blade, where the blade is locked against accidental closure when the blade is in the open position. It is unlocked by a mechanism that allows the blade to be folded and locked in the closed position.

During the 1950s, US newspapers as well as the tabloid press promoted the image of a new violent crime wave caused by young male delinquents with a switchblade or flick knife, based mostly on anecdotal evidence.^[1][2] In 1954, Democratic Rep. James J. Delaney of New York authored the first bill submitted to the U.S. Congress banning the manufacture and sale of switchblades, beginning a wave of legal restrictions worldwide and a consequent decline in their popularity.