Rotary cutter

A rotary cutter of a type adapted to be secured on a rotatable arbor by holding means, comprising:

• a pair of pressing members immovably situated on the arbor by the holding means for rotation together with said arbor, said pressing members having outer pressing surfaces perpendicular to an axis of said arbor, inner pressing surfaces inclined to the axis of said arbor, said inner pressing surfaces facing and extending parallel to one another, and annular shoulders provided at innermost ends thereof, said annular shoulders projecting inwardly from the respective pressing members and abutting each other;
• a pair of clamping members provided on said annular shoulders and immovably situated between said inner pressing surfaces of said pressing members, said clamping members having outer clamping surfaces parallel to each other and inner clamping surfaces inclined against said outer clamping surfaces, said inner clamping surfaces facing and extending parallel to one another so that when said clamping members are turned against said pressing members, angle of said inner clamping surfaces to said arbor changes;
• and
• a rotary blade secured between said inner clamping surfaces of said clamping members and having a plurality of cutting elements on the periphery thereof, said cutting elements having cutting edges with acute cutting angles between a line perpendicular to both a tangential line and a radial line of the rotary blade at a point on the outer periphery thereof and a line parallel to the axis of the arbor at said point on the blade, said cutting angles changing successively from a maximum to zero for respective portions of a groove to be cut;
• whereby after said clamping members are set against said pressing members to determine an inclination angle relative to said arbor, said rotary blade is rotated against said clamping members to adjust the position of the cutting edges for properly cutting the groove by predetermined cutting edges so that the desired shape groove can be obtained.