Utility knife

Abstract

A utility knife includes a hollow handle, for retractably housing a blade mounted on a blade carrier. The blade carrier is pivotally coupled to an actuator. A user can extend or retract the blade through a front slot by depressing an actuating button and sliding the actuator along an actuator glideway and blade carrier along a carrier glideway to a desired position. Once in the desired position a resilient member on the actuator urges protrusions on the actuator into engagement with detents provided within the handle. The blade carrier glideway is provided in an non-parallel orientation with respect to the actuator glideway to obtain a beneficial force transmission to the actuator that tends to maintain engagement between the actuator and the detents. A blade guard at least partially surrounds the front slot to resist upward forces on the: blade during cutting, while a carrier guard contacts a portion of the cutting edge of the blade within the handle to protect the carrier from damage by the blade. The blade carrier and the actuator include abutment surfaces for effectively transmitting axial compression forces on the blade from the carrier to the actuator without exerting excessive force on the joint between the carrier and the actuator. The actuator is substantially rigid and is urged into engagement with the detents by a resilient member, thereby avoiding deflection of the actuator as a result of axial compression forces exerted on the blade.