Microtunnelling system and apparatus
First Claim
1. A backreaming apparatus comprising:
- a plurality of intermediate drill rods configured to connect together to form a string of intermediate drill rod units, each intermediate drill rod unit including a drive shaft rotatably mounted within a casing assembly, the casing assemblies of the intermediate drill rod units being connected together by connections that allow a pull-back load to be transferred through the casing assemblies of the intermediate drill rod units, and the drive shafts of the intermediate drill rod units being connected by connections that allow torque to be transferred through the string of intermediate drill rod units;
a backreamer having a rearwardly facing cutting face positioned adjacent to and facing a first end of the string of intermediate drill rod units; and
an external drive positioned at a second end of the string of drill rod units for applying a pull-back load to the string of intermediate drill rod units and for applying torque to the string of intermediate drill rod units, the torque being transferred to the backreamer by the drive shafts of the intermediate drill rod units and the pull-back load being transferred to the backreamer by the casing assemblies of the intermediate drill rod units, wherein the intermediate drill rod units define a vacuum channel for removing slurry from a hole being backreamed, the vacuum channel having an inlet adjacent the backreamer and an outlet connected to a source of vacuum.
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Accused Products
Abstract
A microtunnelling apparatus and system that includes an external drive system having rotational and linear thrust drive means, a drill head section having drill rotor and drill rod and connecting to intermediate drill rods allowing extension of the boring hole created by the drill head section driven by the drive system. The drill head includes a modular construction having a plurality of circular disc like elements, a bearing module, a steering module, a spacer module, and a mounting module, for axial alignment and abutment and mounting within a cylindrical steering shell. Directional steering of the drill head includes a plurality of substantially radially extending channels in steering module, each with an hydraulically movable protuberance movable by control means to redirect the outer steering casing and thereby redirect the drill head section mounted on the distal end of the drill rods.
153 Citations
24 Claims
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1. A backreaming apparatus comprising:
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a plurality of intermediate drill rods configured to connect together to form a string of intermediate drill rod units, each intermediate drill rod unit including a drive shaft rotatably mounted within a casing assembly, the casing assemblies of the intermediate drill rod units being connected together by connections that allow a pull-back load to be transferred through the casing assemblies of the intermediate drill rod units, and the drive shafts of the intermediate drill rod units being connected by connections that allow torque to be transferred through the string of intermediate drill rod units; a backreamer having a rearwardly facing cutting face positioned adjacent to and facing a first end of the string of intermediate drill rod units; and an external drive positioned at a second end of the string of drill rod units for applying a pull-back load to the string of intermediate drill rod units and for applying torque to the string of intermediate drill rod units, the torque being transferred to the backreamer by the drive shafts of the intermediate drill rod units and the pull-back load being transferred to the backreamer by the casing assemblies of the intermediate drill rod units, wherein the intermediate drill rod units define a vacuum channel for removing slurry from a hole being backreamed, the vacuum channel having an inlet adjacent the backreamer and an outlet connected to a source of vacuum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for installing product comprising:
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drilling a hole by pushing a rotatable cutting face through the ground by progressively adding drill rod units to a string of drill rod units, wherein each of the drill rod units includes an outer casing assembly for transferring thrust to the cutting face and inner drive shafts for transferring torque to the cutting face; monitoring a direction of the string of drill rod units using a laser directed through the string of drill rod units to a target located adjacent the cutting face; after the hole has been drilled, replacing the cutting face with a backreamer; and enlarging the hole by pulling the backreamer back through the hole with the casing assemblies while applying torque to the backreamer with the drive shafts. - View Dependent Claims (20, 21, 22)
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23. A backreaming apparatus including a distal end configured for connection to product and a proximal end configured for attachment to a distal end of a drill string, the backreaming apparatus comprising:
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backreaming cutting elements having cutting sides that face toward the proximal end of the backreaming apparatus; a proximal assembly that extends between the proximal end of the backreaming apparatus and the backreaming cutting elements, the proximal assembly defining a vacuum passage for removing material cut by the backreaming cutting elements, the proximal assembly being configured to be attached to the drill string adapted to pull the backreaming apparatus through a previously drilled hole; a drive stem for transferring torque to the backreaming cutting elements for driving the cutting elements about a longitudinal axis of the backreaming apparatus, the drive stem being rotatably supported within the proximal assembly; and a distal assembly that extends between the backreaming cutting elements and the distal end of the backreaming apparatus, the distal assembly being configured to be attached to product desired to be pulled behind the backreaming apparatus into the hole during backreaming; and a vacuum blocking plate positioned distally with respect to the backreaming cutting elements, the vacuum blocking plate having an outer diameter generally equal to an outer cutting diameter of the backreaming cutting elements. - View Dependent Claims (24)
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Specification