Patent ID: 8484854

Claim:
A blade-switchable utility knife, comprising: a housing defining an internal space therein, an opening, a sliding slot, a switch groove, a pair of first limit portions and a pair of second limit portions; a blade slider received in the internal space of the housing to be slidably movable backwards and forwards within the internal space and to move to at least a blade retraction position and a blade protrusion position, the blade slider comprising a first blade compartment and a second blade compartment, a fixing bulge formed in each of the first and second blade compartments; a slide actuator fixedly disposed on the blade slider, and installed and slidably movable in the sliding slot; a switch actuator slidably installed in the switch groove and comprising a push portion and a follower portion, the push portion capable of being pushed to at least a first switch position and a second switch position; a pair of blades respectively disposed in the first and second blade compartments, each blade of the pair of blades comprising a first concave portion and a second concave portion and being capable of being placed in an operative position and a non-operative position; and a pair of restoring elements used to respectively restore the pair of blades back to the operative positions thereof; wherein when the push portion of the switch actuator is located in the first switch position, the follower portion pushes against the blade disposed in the first blade compartment to move to the non-operative position thereof so as to allow the first and second concave portions of the blade in the first blade compartment to respectively engage with the pair of first limit portions, and the blade disposed in the second blade compartment remains in the operative position thereof with the first concave portion thereof engaging with the fixing bulge of the second blade compartment whereby the blade slider is capable of advancing forward from the blade retraction position to the blade protrusion position by pushing the slide actuator so as to simultaneously move the blade in the second blade compartment extending out of the opening, and when the push portion of the switch actuator is located in the second switch position, the follower portion pushes against the blade disposed in the second blade compartment to the non-operative position thereof so as to allow the first and second concave portions of the blade in the second blade compartment to respectively engage with the pair of second limit portions, and the blade in the first blade compartment remains in the operative position thereof with the first concave portion thereof engaging with the fixing bulge of the first blade compartment whereby the blade slider is capable of advancing forward from the blade retraction position to the blade protrusion position by pushing the slide actuator so as to simultaneously move the blade in the first blade compartment extending out of the opening.