| 摘要 |
An elongate substantially rectangular abrading tool blade, which can be used either for smoothing or for heavy stock removal, is formed of sheet metal and has a multiplicity of ground and hardened cutting teeth distributed over a cutting face of the blade and a multiplicity of associated through-the-blade apertures. The cutting teeth and associated apertures extend in several parallel rows across the blade at an angle other than perpendicular to the longitudinal axis of the blade, with several cutting teeth and associated apertures in each row, all the said cutting teeth facing the same way, namely, perpendicular to the said rows. Each said aperture is directly in front of and adjacent its associated cutting tooth relative to the direction in which the teeth face. Two longitudinal side edge portions of the blade are bent back through an acute angle relative to the cutting face from a longitudinal, substantially flat, middle portion of the blade. The rows of cutting teeth and apertures extend across the full width of the middle portion of the blade and at least to the boundaries of said middle portion with the side edge portions, terminating short of both outside edges of the blade. One of said longitudinal side edge portions comprises edge teeth, which are not ground. The other one of said longitudinal side edge portions is smooth, devoid of edge teeth. The method of making the blade involves the bending back of said longitudinal side edge portions prior to hardening by heat of the blade. The bending back of said longitudinal side edge portions is effected by means of a pair of dies caused to close together and also at the same time to cut the blade from coil. |
