A locking device has a slide accommodated in a stationary casing and spring biased in the direction causing it to project out of said stationary casing. When the slide is retracted into said stationary casing, a locking arm which is pivotally coupled to the slide is turned to a position facing the exposed...http://www.google.fr/patents/US4688834?utm_source=gb-gplus-shareBrevet US4688834 - Locking device
