Abstract: A method and apparatus for edge-trimming a board by means of an edger having two cutter heads adjustable in relation to each other in which the cutter heads are arranged to be movable in a direction transverse to the movement of the board while it is passing the edger. The movement of the cutter heads is controlled in such a manner that a trimmed board of optimum width is obtained.

Abstract: The width of a piece of timber, such as a board is measured with a device including a laser tube emitting laser beam to be reflected by a rotatable mirror polyhedron and a parabolic reflector into a direction along the board, mirror rasters being provided at intervals along the board so as to reflect laser beam pulses onto the board, each raster including a group of mirrors reflecting the beam pulses onto spots of the board that are spaced apart laterally across the board, and detecting means being provided for receiving the pulses reflected from the board surface in order to obtain information about the board width. Preferably, the pulses received by the detectors are transferred to a computer which calculates, in a manner known per se, the optimal sawing width for the board. Instead of the reflector, lens means may be used for directing the beam along the board.