Abstract: A circular saw blade has a rotary axis and a flat annular body arranged therearound. The annular body has a periphery being provided with teeth. The annular body is of hollow conical shape. For manufacturing the circular saw blade, an initially flat annular body is bolted into a concentric conical support element, thereby deforming the annular body into a hollow conical shape.

Abstract: A method and an apparatus are disclosed for separating or slitting a rigid material, in particular a piece of wood, having a modulus of elasticity of between 50,000 and 400,000 kg/cm.sup.2. A narrow tool having chip-removing elements, in particular a circular saw blade, produces a slot or kerf of finite width in the material at a cutting speed of more than 40 m/s. After the chip-removing elements having passed, a separator element bends a side piece out of the slot plane so that after the chip-removing elements have passed, the side piece is always at a distance from the tool. When viewed along the feed direction of the material, the separator element is provided with a hump at a distance from its periphery adjoining the tool and being first to come into contact with the material when the material is fed in. An imaginary connection line extending between the hump and the chip-removing elements is at a distance above a first portion of the separator element lying between the hump and the periphery.

Abstract: A method serves for flattening logs (10) showing a curved longitudinal center line (10a). The logs (10) are conveyed in horizontal position in their longitudinal direction, with their convex side (11) up and their concave side (12) down. The concave side (11) of the logs (10) is flattened from below in the area of their butt ends (27). In order to optimize the yield in wood, the logs (10) are measured before carrying out the flattening step, in a position where they are supported on a reference plane (13) by the end points (20, 22) of their concave side (12) only. The geometrical position of a first point (26) of the log (10) is determined on the convex side (11) as its elevation above the reference plane (13).

Abstract: A method and apparatus for producing lumber products which are machined on all sides. With this method, the curved trunk which is to be machined, and which increases approximately conically in thickness toward one of its ends, is first, prior to flattening its longitudinal sides and cutting off boards, aligned relative to a processing line of sawmill equipment in such a way that its longitudinal central plane, which is disposed in the direction of curvature of the trunk, extends approximately parallel to the machining surfaces of side cutting devices which flatten the longitudinal sides of the trunk. After that, a portion of the large trunk end which projects beyond an alignment plane is flattened. This flattening is effected in a plane which is tangential to the two trunk ends on a convexly curved surface portion thereof.