Abstract: A blade for a utility knife is provided which has a trapezoidal shape with a cutting edge and a pair of side edges which converge towards a blunt back edge. A safety edge joins each of the side edges with the cutting edges. The safety edges intersect with the cutting edge at an obtuse angle and provide substantially blunt surfaces. Safety corners are formed at intersections of the safety edges and the side edges. The safety corners are disposed at the outermost distal ends of the blade relative to the cutting edge. Cutting corners are formed at the intersections of the safety edges and the cutting edge. The cutting corners are disposed inwardly along the cutting edge relative the safety corners. This way, inadvertent contact between an operator and a safety edge would not be likely to cause injury since the safety corners would be contacted first.

Abstract: An improved, adjustable-blade safety knife of the type having a replaceable, single-edge blade slidably-retained within a single-piece handle against a keeper plate having a tang to engage the blade in a side-by-side assembly for protraction and retraction out of one end of the handle has planar guide member extending forward from the cutting end at one side of the knife at a controlled distance from the blade when the blade is extended and at a slight angle relative to the blade such that, when the face of the guide is brought into contact with the surface of a cardboard container, the blade is constrained to cut the side of the carton at a slightly inclined angle from the horizontal and along a line whose spacing from the container top is closely controlled, thereby preventing injury to the container's contents.

Abstract: A holder is described which holds a conventional, single-edge razor blade and permits the blade to be held safely in the hand and used to cut thin, elongated articles, such as sheets or strands by drawing the blade into edgewise contact with the sheet or strand. The cutting edge of the blade is protected except for a portion thereof, which is exposed at the end of a guide slot in the holder, which serves both to guide the article being cut into cutting contact with the blade at an optimum angle of incidence with respect to the blade, and to prevent other articles and parts of the hand from being cut accidently. The blade is replaceable without tools and is reversible to use portions of both ends. A finger extends outward from the holder and parallel to the guide slot to hook the article to be cut into initial engagement into the guide slot.

Abstract: A device for supporting a limp disposable container in a generally open position to receive material and for preventing the container from collapsing as material is inserted therein has rim means for releasably engaging portions of the container peripherally about an opening in the container and for supporting these portions in an open position, second means defining a base for providing stability for the device relative to a surface upon which the device is positioned, strut means interconnecting the rim means and the second means for maintaining a desired spaced relationship therebetween and mounting means for securing the rim means and the second means to the strut means to provide a rigid support device for the limp container. The device may be provided in unassembled kit form of primarily straight tube sections suitable for assembly in an easy and facile manner.

Abstract: A device for longitudinally slitting generally cylindrical objects has body means for supporting a cutting element, alignment means for positioning the cutting element relative to the body means, bearing shoulder means for longitudinally aligning the cylindrical object with respect to the cutting element and positioning the cylindrical object such that a surface thereof contacts the cutting element and protective means adjacent the cutting element for protecting the cutting portion of the cutting element when the device is not in use and, at the same time, being moveable to expose the cutting portion of the cutting device when a cylindrical object bears against the bearing shoulder means.

Abstract: An adjustable blade knife is made by extruding a continuous strip of extrudable hardenable material with the strip having a planer web between thicker marginal portions and opposing slots in the marginal portions, individual knife handle bodies are stamped from the strip and a knife blade is assembled to each body by inserting the blade in the opposed slots of the body. The blade is preferably preassembled to a slide plate with the slide plate and blade positioned together in the handle body slots to slide along the web portion of the handle body which is provided with a longitudinally extending slot having at least one side wall of an irregular surface configuration to co-operate with positioning means provided on the slide plate to facilitate locating the blade-plate sub-assembly in adjustable positions of use.