A drilling and tapping machine includes a power head assembly supported at a vertical orientation, a parallelogram arm structure including a head support and an arm base, and an arm positioning assembly coupled with the head support and the arm base support for guiding corresponding movements of the head support and the arm base support so as to ensure a vertical trajectory of the power head assembly. The machine further includes a counterweight configuration to vertically move the power head assembly via a lever. The machine further includes an operational control assembly to selectively shift the power head assembly between a drilling operation and tapping operation. Therefore, the machine is suitable to make a hole with a diameter of 0.5 to 3 mm.

The present application pertains to a rebar hole doweling cart to construct or repair sidewalks, driveways, roadways, curbs, floors and the like. The cart has a frame with wheels, an elongated upwardly extending riser with a handle, and a nose piece that pivotally supports a drill mounting assembly near the ground. The mounting assembly holds an electric hammer drill and its bit in an aimed direction. The cart is rolled forward to tap a hole in a concrete slab and place the bit in a set aimed direction. The cart handle is then pushed forward with the nose piece in gripping engagement with the ground to advance the drill bit forward to form the rebar hole in the slab. During this forward handle rotation, the drill mounting assembly simultaneously counter-rotates (pitch pivotal movement) relative to the nose piece to substantially maintain the drill bit in its set aimed direction.