Box cutter with autoretracting blade

Abstract

A knife has a housing and a blade slide carrying a blade and displaceable longitudinally in the housing between a rear retracted end position with the blade wholly received in the housing and a front extended end position with the blade extending forward from the housing and through an intermediate position. A spring urges the blade slide continuously rearward into the retracted position. An actuator slide is displaceable in the housing independently of the blade slide between a front end position and a rear end position and through an intermediate position and is provided with an externally accessible actuating formation. Another spring urges the actuator slide continuously into the rear position. A seat member on one of the slides is displaceable along a path on movement of the one slide between its end positions and a coupling member on the other of the slides is engageable in the seat member on forward movement of the actuator slide from its rear position into the intermediate position of the actuator slide for pushing the blade slide forward from its rear retracted position to its intermediate position on displacement of the actuator slide from its intermediate position to its front position. The members are disengaged from each other and the coupling member is displaced out of the path of the seat member on displacement of the blade from its intermediate position into its extended position.