A utility knife has a housing in which a particle flow cross section is substantially constant or increases in a flow direction of particles from an inlet of the housing into an interior of the housing at an end of the housing to an outlet of the housing. A blade assembly has a blade with a cutting edge and is movable relative to the housing between a stowed position and an operating position for a cutting operation. A first actuating part and a second actuating part mounted movable relative to the first actuating part move of the blade assembly between the stowed and operating positions. First and second slotted links form a four-point linkage with the first and second actuating parts.