Umbrella Arch Systems
3-Channel Pilot Bit
The FATE Engineering 3-Channel Pilot Bit is a high-performance bit for pre-drilling, guidance and cuttings removal in Umbrella Arch Systems.
About the product
3-Channel Pilot Bit
The 3-Channel Pilot Bit is a high-performance drilling bit designed for predrilling and guidance operations in Umbrella Arch Systems. Its three-flute design maximizes debris removal in steel pipe umbrella arch installations and reduces tunnel boring time.
This pilot bit precisely defines the drilling line before ring bit applications, ensuring safe installation. Made of high-strength material, it offers long-lasting and efficient use in a variety of rock types.
Applications
Predrilling and guidance of umbrella arch pipes
Preparation for ring bit applications
Cutting removal and precise installation during tunnel boring
Features
Triple-flute design for maximum debris removal and guidance
High wear resistance and long service life
Compatible with various rock types and drilling machines
Fully compatible with Umbrella Arch Systems
Technical data
3-Channel Pilot Bit technical data.
3-GROOVE PILOT BIT
| THREAD TYPE | MODEL | OUTER DIAMETER | THICKNESS |
|---|---|---|---|
| R32,T38,R38 | 2'' | 60 | 3-4 mm |
| R32,T38,R38 | 3'' | 76 | 3-4 mm |
| R32,T38,R38,T45,T51 | 3,5'' | 89 | 4-6 mm |
| R32,T38,R38,T45,T51 | 4'' | 102 | 6-8 mm |
| R32,T38,R38,T45,T51 | 4,5'' | 114 | 6-8 mm |
| R32,T38,R38,T45,T51 | 5'' | 127 | 6-8 mm |
| R32,T38,R38,T45,T51 | 5,5'' | 139 | 6-10 mm |
| R32,T38,R38,T45,T51 | 6'' | 168 | 6-10 mm |
Gallery
In the same group
Umbrella Arch Systems
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Tunnel
Two-Slot Ring Bit
An annular drill bit fitted to the front of the pipe-umbrella tube, working together with the pilot bit. While the pilot bit drills the centre of the hole, the ring bit enlarges it to the diameter needed for the tube to advance. In weak geological conditions, such as fault zones, weathered and blocky rock or loose ground, the hole often collapses and drilling becomes difficult. Because the tube advances with the drilling, the hole is kept open and the umbrella tube is placed directly in position. When drilling is complete, the pilot bit is released from the ring bit’s two-slot connection and withdrawn through the tube; the ring bit remains in the ground with the tube. Tungsten carbide buttons on the face break the ground, while flushing channels help carry the cuttings out.
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Tunnel
Three-Slot Ring Bit
An annular drill bit at the front of the pipe-umbrella tube, working together with the pilot bit. While the pilot bit drills the centre of the hole, the ring bit enlarges it to the diameter needed for the tube to advance. Advancing the tube with the drilling keeps the hole open and places the tube in position, especially in loose and collapsing ground. The three-slot connection transfers rotation and impact from the pilot bit to the ring bit. Tungsten carbide buttons on the face break the ground, while flushing channels help clear the cuttings. When drilling is complete, the pilot bit is released from the connection and withdrawn through the tube; the ring bit remains in the ground with the tube.
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Tunnel
Two-Slot Pilot Bit
The centre drill bit used together with the ring bit in pipe-umbrella drilling. While drilling the centre of the hole, the pilot bit transfers rotation and impact to the ring bit through its two-slot connection. The ring bit then enlarges the hole to the diameter needed for the tube to advance, and the tube is placed as drilling proceeds. Tungsten carbide buttons on the face break the ground, while flushing channels help clear the cuttings. When drilling is complete, the pilot bit is released from the ring bit and withdrawn through the tube for reuse; the ring bit remains in the ground with the tube.
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Tunnel
Umbrella Pipe
A steel pre-support tube installed before excavation from around the tunnel face in the direction of advance, along the crown at a slight outward angle. Installed side by side, the tubes form a protective umbrella above the section to be excavated, limiting ground movement and helping to maintain stability during excavation. Mainly used at portals, in fault zones and in weak, weathered and collapsing ground. Successive umbrellas overlap to provide continuous pre-support along the drive. With the pilot bit and ring bit system, the tube advances into the ground as drilling proceeds. When drilling is complete, the pilot bit is withdrawn; the tube and ring bit remain in the ground. Where required by the design, grout is injected through the tube and its injection holes to fill voids between the tube and the surrounding ground. Tube diameter, wall thickness, length, connection type and overlap length are selected according to ground conditions, tunnel geometry and the support design.
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Tunnel
Male / Female Coupling
Male and female couplers that join pipe-umbrella tubes end to end with a threaded connection. Tubes are added as drilling proceeds until the length specified in the design is reached. The connection transfers rotation and impact from one tube to the next during drilling and keeps the tubes on a common axis. During excavation, the joint must be as strong as the tube under the ground load it carries; coupler wall thickness and thread length are selected accordingly.