Bolt hole locating and marking tool

A self contained hand actuated inertial impact marking tool for establishing and marking predetermined distances on concrete and the like, comprising:

• an elongated generally flat rectangular base member having a support face and an aperture therein intermediate the ends thereof, the length thereof between said aperture and said ends defining means for establishing predetermined distances;
• an elongated tubular guide member secured at one end to, and extending upward from said base member in alignment with said aperture;
• a hand actuated inertial impact member defined by an elongated bar having a sharp point on the lower end and an elongated, cylindrical grip handle adapted to extend through and be gripped by the hand on the upper end mounted in said tubular guide member on said base member and having said sharp point positioned for extending through said aperture for establishing a mark upon impact engagement with a surface, said bar and said tubular member having sufficient length extending from said base member to extend from said base member at the foot of a workman upward to his waist, to enable a workman in the upright position to grasp the grip handle in his hand and said elongated bar having sufficient mass to enable hand actuation to mark on a concrete floor at the feet of said workman;
• and
• a coil spring disposed between a pair of opposed annular flanges disposed respectively on the upper end of said tubular member and adjacent said handle on said elongated bar for normally supporting said impact member so that said point does not protrude beyond said support face,
• a semi-circular cut out at each end of said base member for receiving a bolt, and
• clamping means for clamping said elongated bar to said tubular member.