An adjustable safety utility knife includes a 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. A
fastener secures the shell members together at their
peripheral edges along a parting plane to form an elongated
internal cavity. The
handle defines a front end, back end and an intermediate portion suitable for being gripped by a user and also defines top and bottom surfaces extending along opposite sides of the shell members along the
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. The
cutting blade is mounted for movement by a suitable guide member or a
carriage between a first position for safely storing the blade fully inside the cavity and a second position for selectively extending the blade beyond the aperture to
expose at least a portion thereof. A manually operated button is arranged on the top surface of the handle and is coupled to guide element or blade
carriage for selectively moving the blade between the first and second positions. Slip resistant elements are secured to the shell members along the top and bottom surface between a rearwardmost operative position of the manually operated button and the back end of the handle. The slip resistant elements generally conform to the outer convex surface of the handle and enhance gripping of the handle and minimize slippage thereof during use of the utility knife when gripped by a user.