Grinding guide assembly for a hand-held grinding machine for buttons of a button drill bit

A grinding guide assembly for a hand-held grinding machine having a body from which a rotary spindle projects, rotates about its own longitudinal axis and mounts a grinding disk having a radially outwardly opening groove that is generally U-shaped in longitudinal cross-section and flanked by two axially opposite radially outwardly facing shoulders, for receiving in said groove between said shoulders as said grinding disk rotates, and said body is hand-held, a respective generally hemispherical button having an outer perimeter of a given diameter, which button protrudes from a surface of a button drill bit body,

• said grinding guide comprising:
• a cover for an upper side of the grinding machine;
• means for securing the cover to the body of the grinding machine so that a portion of the cover extends into radially spaced, radial adjacency with the generally U-shaped groove in the grinding disk mounted to the spindle of the grinding machine on one side of the longitudinal axis of the spindle;
• a guide spring means having a central portion and two angularly opposite finger-like end portions based on said central portion and having respective free ends;
• and
• locking means securing said central portion of said guide spring means to said cover, so that said end portions of said guide spring means extend past said axis and said free ends project towards one another from angularly opposite directions and are disposed to engage the outer periphery of the button at two respective diametrically opposite sites.