Fixtures for holding a tool subject to grinding

Claim 1

A fixture to support a cutting tool for grinding comprising a base and a carrier block extending upwardly therefrom, a positioning block mounted on said carrier block, said positioning block having a flat tool holder receiving surface with a hole through said tool holder receiving surface for rotatably supporting a tool holder, indexing holes on opposite sides of said tool holder hole, a first zeroing hole positioned at a point spaced from said tool holder hole, said tool holder having a center line being formed perpendicular to a line between said zeroing hole and said tool holder hole, said positioning holes including a pair of holes positioned slightly above the center line to utilize in grinding square thread cutters, tool holder means for holding tool steel subject to grinding rotatably positioned in said tool holder hole and adapted to be removably positioned with one end of said tool holder in one of said positioning holes said base and carrier block being integral with one another, said carrier block tilting slightly from the vertical and said base extending outward under said positioning block and forming a horizontal ledge, said positioning block lowermost portion, when in a vertical position, touching said horizontal ledge, said positioning block having along the bottom thereof, when in said vertical position, a semicircular portion with a measuring scale thereon, the other portion of said positioning block having flat side surfaces, said tool holder hole being in said other portion of said positioning block, said positioning block being rotatably mounted to said carrier block at the center of said semicircular portion to a position wherein one of said flat side surfaces abut said horizontal ledge.