Eccentric Overburden Drilling System

Concentric casing system with blocks is applicable to all kinds of core drilling rig, bolt rig, for geological exploration, deep foundation pit support, high slope anchorage, tunnel collapse tube shed support, pebble layer high pressure rotary jet and other fields

1. Eccentric Reamer System Step-by-step

1) When drilling starts, the reamer swings out and reams the pilot-hole wide enough for the casing tube to slide down behind the drill bit assembly.

2) When the required depth is reached, rotation is reversed carefully, whereupon the reamer swings in , allowing the drill bit assembly to be pulled up through the casing.

3) Casing tubes that are to be left in the drill hole should be sealed at the bottom of the hole by means of cement grout or some other sealing agent.

4) Drilling continues to the desired depth in the bedrock using a conventional drill string.

Application Range:

This product is made of alloy of high quality and apply for advanced high-frequency welding technology and maturity of heat treatment process, greatly improving the intensity, wear resistance and impact toughness of cutter head, increasingly prolonging the working life, enhancing the drilling efficiency.

It is recommended to drill in rock formation where contains some ovals and fractures.

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2. General Introduction

1) drill in overburden unstable rock
2) one step to drill and follow casing
3) flexible to open or close
4) effecient below 300mm


3. Design Principles:

Make the casing follow easy and the equipment and operation simple
Outstanding Advantages
Simple structure,simple operation,reliable quality,retrievable drilling tools,long service life.


4. Raw Material

Steel:
first class special alloy steel with high strength, heat resistance and wearable
Carbide:
The best tungsten carbides from China are commonly applied.
Tungsten carbide from European is also available.


5. Working Process:

1. Ring bit and casing shoe assembly is welded to casing prior to drilling. Lock the assembly into pilot bit with hammer. The pilot bit's upper shoulder engages the shoulder of the casing shoe.
2. On completion of drilling and casing, the drill string with pilot bit is retrived by a slight reverse rotation to unlock the bayonet coupling. The ring bit stays in the hole, and can be recovered only if the casing is retrieved.
3. Hammer's percussive energy is transferred through the pilot and ring bits, crushing rock. Part of impact energy advances casing.
4. Drilling continues to the desired depth in the bedrock using a convertional drilling.

6. Contact us :

We are a Robert Roschen family owned Global leading manufacturer of rock drilling tools, like Roller Tricone Rock Bits, Hole Opener, Single Cone Roller Bits, PDC Bits, Diamond PCD Tricone Drill Bits, DTH Drilling Tools, such as DTH hammers and bits, DTH drill pipes, RC hammers and bits, tophammer button bits, coupling, cross bits, drill rods located in Germany, China(joint-venture).

We have rich experience in this field of Roller Tricone Bits, PDC Drill Bits, Oil Drilling Toosl, Rock Drilling tools, DTH hammers and bits for 60 years.

Owing to high quality, professional serivce and competitive price, we have gotten good reputation from our customers from all over the world, such as US, Canada, France, Spain, Italy, South Africa, South Latin Amercia, Brasil, Saudi Arabia, UAE, Iran, Malaysia, Australia, etc.