Centering device

A centering device for use in a tool machine having a horizontal spindle wherein a circular milling cutter is mounted for cutting a cylindrical workpiece, comprising:

• an aligning fixture having a base provided with an elongated channel along a longitudinal center line, a pair of holding blocks slidably disposed in said channel of said base, said holding blocks mounted on a leadscrew capable of moving said pair of holding blocks towards each other to meet at a center position of said base when said leadscrew is turned in one direction and each moving apart an equal distance from said center position of said base when said leadscrew is turned in the opposite direction each of said holding blocks being provided with a cut-in and a lock screw adapted to lock the holding block on said leadscrew when said lock screw is tightened, an arm firmly fixed onto one side of said base, said arm having a center line perpendicular to said longitudinal center line of said base and passing through said center position of said base;
• and
• a centering pointer having a needle slidably held within a hollow holder and resiliently urged outwardly by a spring in said hollow holder, said needle being provided with a lever perpendicularly fixed thereto and capable of moving with said needle, said centering pointer being mounted onto said arm in said aligning fixture with said needle passing through and being perpendicular to said center line of said arm.