Drill apparatus having a primary drill and a pilot drill
OwnerRobert N. Behrensinventor
Life of this patent
Estimating the term…
Abstract
Drill steel or bit apparatus includes a primary drill bit having a base and a stem, a drill tip, and a bore extending longitudinally through the base, the stem, and the tip, and a pilot drill bit having a base and a stem, and a tip, and the stem and the tip extend through the longitudinal bore in the primary drill bit. The pilot drill bit includes a longitudinally extending bore through which compressed air flows. The base of the pilot drill bit is impacted by a drill piston and the base of the pilot drill bit in turn impacts the primary drill bit. Drilling is accomplished by the tips of both the pilot drill and the primary drill bit.
Claims6
Drill bit apparatus, comprising, in combination:
- primary drill bit means for drilling holes, including
- first base means for securing the primary drill bit means a drill chuck, said first base means having an axially extending portion having flat surfaces thereon adapted to be received by said drill chuck,
- a first stem portion connected to the first base means,
- drill tip means connected to the stem portion and including
- a plurality of drill tips, and
- slots disposed between the drill tips of the plurality of drill tips, and
- first bore means extending through the first base means, the stem portion, and the drill tip means through which compressed air flows;
- and
- pilot drill means, including
- second base means having a rear impact face for receiving an impact for drilling and a front impact face for impacting the first base means of the primary drill bit means,
- a second stem portion connected to the second base means and extending through the bore means of the primary drill bit means,
- a tip connected to the second stem portion remote from the second base means and extending outwardly from the drill tip means of the primary drill bit means, and
- second bore means extending through the second base means and the second stem portion through which compressed air flows to blow dust and debris from the hole being drilled.
Dependencies are inferred from the claim text.