Abstract: A blade scabbard including a safety lock which functions to prevent accidental or inadvertent withdrawal of a blade from a fully inserted position within the scabbard housing. The safety lock operates automatically in response to insertion of a blade into the scabbard and is preferably associated with blade sharpening mechanism which is also responsive to movement of a blade into and out of the scabbard housing. The sharpening mechanism is preferably inactive during blade insertion and active during blade withdrawal. Manually operable release means is provided to enable release of the lock for blade withdrawal purposes, and it is necessary to operate the release means while simultaneously withdrawing the blade from the scabbard. The safety lock is fully released after the blade has been withdrawn a distance from the fully inserted position and operation of the release means can then be terminated without hindering further withdrawal of the blade.
Abstract: The invention relates to knife blades and their methods of production. Whilst it has long been known that the surface hardness and wear resistant properties of metal objects can be enhanced by a hard surface provided on them, the effective employment of this in relation to knife blades has proved difficult to achieve. The object of the invention is to provide a knife blade with a cutting edge of a harder material than the body of the blade, and the objective is met by a construction comprising a v-shaped cutting edge formed on a blank and such that the cutting tip lies substantially centrally of the width of the blank characterised in that one side face of the v-shaped cutting edge is provided with a coating of a material harder than the material of the blank, the actual cutting edge being formed wholly of the harder material, and the coating having a columnar crystal structure that extends away from the surface of the blank and to the outer face of the coating.
Abstract: The invention relates to knife blades and in particular to a method of their production, and has for its object the provision of a knife blade with a cutting edge formed by a surface harder than the material of the body of the blade. This objective is met by a method comprising grinding a first face (2) of a V-shaped cutting edge to one side of the blank (1) to locate the lower edge of the first side face (2) at the approximate mid-point across the thickness of the blank (1), providing on the partly-ground blank (1) a hard surface (3) around the periphery of the blank (1) at least over the height of the first ground face (2) and grinding a second face (4) of the V-shaped cutting edge to the opposite side of the blank (1), to locate the V-shaped cutting edge at the approximate mid-point across the thickness of the blank (1).
Abstract: A blade sharpener of the kind having a pair of overlapping plates which are relatively arranged to form a vee shaped sharpening recess between them. Each of the opposite sloping sides of that recess is formed by an operative edge of a respective one of the two plates, and each of those edges extends between a front face and a back face of the respective plate. A relatively sharp corner is formed between each operative edge and the back face of the respective plate, and a relatively blunt--e.g., rounded--corner is formed between each operative edge and the front face of the respective plate. The plates may be mounted on a member which can pivot between a position at which the plates tilt forward and a position at which the plates tilt back. Spring means may be operative to engage the back edge of a blade located in the recess so as to press the cutting edge of the blade against the plates.
Abstract: A blade sharpener having a sharpening mechanism which functions to sharpen a blade engaging that mechanism and being moved longitudinally relative thereto. The sharpener also includes sharpening defeating means which, when operative, at least inhibits and possibly prevents sharpening of a blade by the sharpening mechanism when that blade is moved longitudinally through the sharpener in one direction. The defeating means is responsive to blade movement so as to adopt an operative condition when the blade is moved in the aforementioned one direction, and to adopt an inoperative condition when the blade is moved through the sharpener in the opposite direction. The defeating means includes a blade engaging member such as a roller, and in the operative condition that roller engages and presses against the cutting edge of the blade so as to impose a force on the blade which acts counter to the force causing the blade to engage the sharpening mechanism.