US Patent 11565432 Utility knife

A utility knife has a housing having a longitudinally open front end, a blade assembly including a blade and movable in the housing between a front end position and a rear end safety position, and a lever pivoted on the housing. Two links each have one end pivoted on the blade assembly and an opposite end pivotal on the lever so as to pivotally interconnect the blade assembly and the lever for relative movement of the blade assembly and the housing between the rear end safety position with the blade inside the housing and the front end position with the blade projecting longitudinally forward from the front end of the housing. A spring is connected to the links urges the blade assembly into the rear end safety position.