An adjustable safety utility knife includes an elongated ergonomically shaped
handle formed of two elongate shell members each having a
peripheral edge and an outer generally convex surface and an inner generally
concave surface. The shell members are fastened at the
peripheral edges along a vertical parting plane to form an elongated
internal cavity. The
handle defines a front end, a back end and an intermediate portion suitable for being gripped by a user and also defining top and bottom surfaces extending along opposite sides of the shell members along said
peripheral edges. The
handle has a slot-like aperture at the front end substantially aligned with the parting plane and dimensioned for passage of a flat
cutting blade therethrough. A guide element within the elongated cavity guides the
cutting blade between a first position for safely storing the blade fully inside said cavity and a second position for selectively extending the blade beyond the aperture to
expose at least a portion thereof. A manually operated button arranged on the top surface is coupled to the guide element for selectively moving the blade between the first and second positions. The handle has a rear opening at the back end for providing access to the elongated
internal cavity. A carrier frame has a blade
cartridge receiving compartment and dimensioned to be removably receivable within the cavity through the rear opening between a retracted position in which the carrier frame is fully stored within the
internal cavity of the handle end and an extended position in which the carrier frame is at least partially moved exteriorly of the back end to provide access of the
cartridge receiving compartment. A blade
cartridge for storing a plurality of flat
cutting blades is receivable within the blade cartridge receiving compartment.