Abstract: An adjustable manual abrasive sharpener having a pair of sharpening slots formed in a frame with opposing abrasive arms being pivotally mounted in each of the sharpening slots. A rod is mounted on the frame for rotatable motion and for linear motion long its axis of rotation from a position at which the rod is locked against rotation to a depressed position whereby the rod may be rotated. The bottom end portion of the rod includes a pinion gear which engages a pair of gear racks which are mounted for movement laterally relative to the axis of rotation of the rod. The pair of gear racks respectively engage slots formed on the bottom of the abrasive arms in each sharpening slot. Rotation of the rod causes movement of the gear racks to adjust each pair of abrasive arms with respect to each other to vary the sharpening angle of the abrasive elements.

Abstract: A grinding fixture that allows a variety of helical shapes to be ground upon a variety of cutting inserts. The grinding fixture includes a bottom sine base for varying a first angle. A shaft is rotatably attached to the bottom sine base for providing rotation of the insert about an axis. A primary slide is rotatably attached to the shalt in parallel relation to the top surface of the bottom sine base for adjusting the position of a locating point on the insert in a first direction relative to the axis of rotation. The locating point is adjusted in a second direction relative to the axis of rotation by a cross slide attached to, and disposed in perpendicular relation with, the primary slide. A top sine assembly is fixedly attached to the cross slide for varying a second angle and includes a connection surface for fixedly connecting the insert holder to the sine assembly.