Method and apparatus for reaming pilot hole
AssigneeJapan Drilling Co., Ltd.
InventorShohei Kato
Life of this patent
Estimating the term…
Abstract
By using a reaming machine which arranges a plurality of hydraulic hammer driven drill bits in parallel on a cross section to be reamed, a horizontal or gently inclined pilot hole is reamed. A pressurized water introducing drill pipe and a drill pipe as a discharge pipe are connected to the reaming machine, a seal which forms a sealing between the drill bits and a reamed hole is provided, and a passage for feeding drilling water into the drill pipe is provided, whereby the reaming machine can be propelled while discharging cuttings with a small amount of water through the drill pipe.
Claims5
A pilot hole reaming method for reaming a horizontal or gently inclined pilot hole, comprising:
- employing a reaming machine having a plurality of hydraulic hammer driven drill bits in parallel on a cross section to be reamed;
- connecting drill pipes to at least one of a trailing-end side and a leading-end side of the reaming machine;
- and
- discharging cuttings through at least one of the pilot hole and the drill pipe while reaming.
A pilot hole reaming apparatus, comprising:
- a reaming machine having a plurality of hydraulic hammer driven drill bits in parallel;
- drill pipes connected to at least one of a trailing-end side and a leading-end side of the reaming machine;
- and
- a seal mounted on an outer periphery of the reaming machine to form a seal between a drill-bit side front surface and a rearward side of the reaming machine.
Dependencies are inferred from the claim text.