SAW TOOTH EDGE FOR PORTABLE ELECTRIC MOTOR-DRIVEN CUTTING TOOL

PURPOSE:To suppress an increase of power to a minimum in a tool, even when it cuts a thick material, so as to prevent a cutting speed from decreasing, by constituting the tool forming a rake angle of a saw tooth edge, which protrudes to the bottom from a guide surface plate, smaller as the saw tooth edge advances to the point end side and setting the actual rake angle to the optimum value. CONSTITUTION:In the vicinity of a guide surface plate 4, a saw tooth edge 3 mounts its tooth end A1 to a swivel arm 5, and from a relation between a straight line A1-R1, crossing at a right angle with a tooth end line passing the tooth end A1, and a straight line A1-Q1, crossing at a right angle with a straight line P1=P1-showing the major axis of a locus of the tooth end A1, a tool obtains a rake angle beta21 in a minus value and the actual rake angle beta21' in a plus value. While in the point end part, from a relation between a straight line A2-R2, crossing at a right angle with a tooth end line passing through a tooth end A2, and a straight line A2-Q2, crossing at a right angle with a straight line P2-P2 showing the major axis of a locus of the tooth end A2, the tool obtains a rake angle beta22 in a minus value and the actual rake angle beta22' in a plus value. And the tool changes the rake angle from beta21 to beta22 so that the actual rake angle beta22' equals almost beta21'.