Extendable pilot for barrel cutter
AssigneeTerex USA, LLC
InventorJohn Pantzke
Life of this patent
Estimating the term…
Abstract
A system and method for boring a hole in rock with a digger derrick; which utilizes a hollow stem auger, a kelly bar, and a core barrel with a top support member with a hole therein for receiving the kelly bar with a detachable central pilot bit thereon which is translatable up and down with respect to the core barrel as the kelly bar and auger are manipulated. The kelly bar is selectively positionable with respect to the auger so as to allow the ability to retract the pilot bit inward into the core barrel and to shorten the separation between the pilot bit and the auger.
Claims20
A system for boring holes with a digger derrick comprising:
- a shaft configured to be coupled to a source of rotary power;
- a core barrel having a barrel top and a barrel bottom and configured to rotationally couple to said shaft so said shaft provides rotary power to said core barrel and said shaft is free to translate within said core barrel in a direction from said barrel top toward said barrel bottom;
- and
- a pilot bit coupled to said shaft, so that said pilot bit is free to translate within said core barrel in a direction from said barrel top toward said barrel bottom and said pilot bit is rotated by said shaft without said pilot bit receiving rotation forces through said core barrel.
A system for boring holes with a digger derrick comprising:
- an auger configured to be coupled to a source of rotary power;
- said auger having a hollow central stem;
- a shaft configured to be received in said hollow central stem;
- a core barrel having a barrel top and a barrel bottom and configured to rotationally couple to said shaft and thereby receive rotary power from said shaft;
- and
- a pilot bit which is coupled to and rotated by rotation forces from said shaft which rotation forces are provided to said pilot bit without being transferred through said core barrel.
A system for boring holes with a digger derrick comprising;
- means for providing rotary power;
- means for cutting a cylindrical hole into a layer of rock, with said rotary power;
- where said cylindrical hole is at least 12 inches in diameter;
- means for cutting a central pilot hole with said rotary power;
- and
- said means for cutting a central pilot hole being configured to selectively translate through and beyond a bottom end of said means for cutting a cylindrical hole;
- said means for providing rotary power comprises:
- a digger derrick;
- a shaft coupled to and rotated by the digger derrick;
- said means for cutting a cylindrical hole comprises a core barrel rotationally coupled to and receiving rotary power from said shaft;
- and
- said means for cutting a central pilot hole comprises a pilot bit rotationally coupled to said shaft but said pilot bit does not receive rotary power through said core barrel.
A method of boring a large hole in rock which is suitable in size to receive therein a telephone pole, the method comprising the steps of:
- providing a mobile source of rotary power with a member configured to receive a shaft therein;
- providing a core barrel, configured to receive rotary power from said shaft;
- providing a pilot bit centrally disposed with respect to said core barrel;
- rotating said core barrel and said pilot bit with said mobile source of rotary power without rotary power being provided to said pilot bit through said core barrel;
- and
- while said core barrel and said pilot bit are being rotated;
- translating said pilot bit with respect to said core barrel and along a central line through said core barrel.
Dependencies are inferred from the claim text.