Abstract: A wood chipper knife includes a knife body and, in relation to a vertical axis of the wood chipper knife, at least one cutter side, which comprises a top cutting edge portion and a bottom cutting edge portion that intersect to form a cutting edge. The bottom cutting edge portion includes a planar wood attacking portion, which begins at the cutting edge and towards the knife body is followed by a recess. The recess is a pressure release recess, which, from the wood attacking portion, abruptly falls to a bottom of the pressure release recess, and which stretches from the wood attacking portion to the knife body. The knife body comprises a chip guiding portion, which, from the pressure release recess, rises towards the knife body.

Abstract: A chipper knife adapted to be mounted in chippers which have a rotatable tool, in the form of a disc, drum or frustoconical member, on which a plurality of chipper knives are mounted has at least one cutting edge which is defined between two edge-forming surface portions of the knife at an acute angle to each other. At least one of the two edge-forming surface portions extends from the cutting edge inwardly to a shoulder extending parallel to and facing away from the cutting edge and defining a step surface on the knife behind the shoulder with respect to the rest of the adjacent knife surface and chipper knife.

Abstract: A knife includes first and second edges, a ridge, a concave surface, and a planar surface. The edges are defined by intersections of outer edge forming surfaces on an outer side of the knife and inner edge forming surfaces on an inner side of the knife. The ridge is on the inner side and the crest of the ridge is parallel to the first and second edges. The concave surface is between an inner edge forming surface and the ridge, and the planar surface is adjacent to the concave surface and between that first inner edge forming surface and the concave surface. A reference plane intersects the first and second edges, and a distance between any point on the concave surface and the reference plane is not less than a distance between any point on the planar surface and the reference plane.

Abstract: The invention relates to a chipper knife of the type that is adapted to be mounted in chippers which have a rotatable tool, in the form of a disc, drum or frustoconical member, on which are mounted a plurality of such chipper knives to provide, during rotation of the tool and simultaneous feeding of pieces of wood to the same, material-cutting working or disintegrating of the pieces of wood into chips. The chipper knife comprises at least one cutting edge (7) which is defined between two edge-forming surfaces (9, 10) at an acute angle to each other. At least one of the two edgeforming surfaces is formed with a thickened cutting edge portion (12) in the area next to the cutting edge, said thickened cutting edge portion having a shoulder edge (13) toward the rest of the edge-forming surface and forming an angle to, or having a different centre of curvature to, the rest of the edgeforming surface. The invention also relates to a method of manufacturing such a chipper knife.

Abstract: A knife includes first and second edges, a ridge, a concave surface, and a planar surface. The edges are defined by intersections of outer edge forming surfaces on an outer side of the knife and inner edge forming surfaces on an inner side of the knife. The ridge is on the inner side and the crest of the ridge is parallel to the first and second edges. The concave surface is between an inner edge forming surface and the ridge, and the planar surface is adjacent to the concave surface and between that first inner edge forming surface and the concave surface. A reference plane intersects the first and second edges, and a distance between any point on the concave surface and the reference plane is not less than a distance between any point on the planar surface and the reference plane.

Abstract: A knife for a disk chip cutting machine which is mounted between a carrier part and a clamping part and which includes a chip breaking surface extending into an opening adjacent an outer surface of the carrier part. The chip breaking surface includes a concave portion which terminates in a rib which extends outwardly and downwardly with respect to an interface between the knife and the carrier part with the concave portion being oriented to direct cut chips in a direction away from the outer surface of the carrier part during use.

Abstract: A knife for a disk chip cutting machine which is mounted between a carrier part and a clamping part and which includes a chip breaking surface extending into an opening adjacent an outer surface of the carrier part. The chip breaking surface includes a concave portion which terminates in a rib which extends outwardly and downwardly with respect to an interface between the knife and the carrier part with the concave portion being oriented to direct cut chips in a direction away from the outer surface of the carrier part during use.

Abstract: A knife for disk type chip cutter machines with a circular rotatable cutter disk (10) on its first axial side being provided with several knives running from the disk centre to its periphery. An opening (14) is provided in the disk in connection with each knife. The opening (14) has a chip guiding surface to guide separated chips to the other axial cutter disk side. The knife includes a knife carrier, on which the knife Is fixed between a first carrier part (18) provided essentially in line with the first axial cutter disk surface and second carrier part (16) extending downwards in the opening from said cutter disk surface into the cutter disk inside and being a part of the chip guiding device. The knife (12) is on its side facing the other carrier part provided with a chip breaking surface (22) passing the other carrier part (16) into the opening and protecting said carrier part from wear in that the separated chips by means of the chip breaking surface are guided in a direction away from the carrier part.