Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH DRILLING; MINING
  • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B10/00—Drill bits
  • E21B10/36—Percussion drill bits
  • E21B10/38—Percussion drill bits characterised by conduits or nozzles for drilling fluids

Definitions

• This invention relates to a drilling apparatus by means of which a hole is drilled into rock or stony soil and soft clay. While drilling the hole, soft soil is forced aside and rock and stones are drilled away.
• Holes have been made in soft soil also by drilling, for instance by rotation of a wing bit or a screw bit, through which or con ⁇ veyed by which soil has been easily conveyed backwards as a huge flow of mass and removed from the hole.
• the above mentioned drilling devices are applicable means to make holes in a certain type of soil and it is hardly possible to make holes with them in any other type of soil.
• the most significant advantage of this invention can be con ⁇ sidered the possibility to make a hole into all possible types of soil with one and the same drill bit. It is not necessary to examine the quality of soil nor to change drilling apparatus or drill bit when the soil type changes. When the bit is hammering and rotating and fitted with working means, it can drill rock and stones. Further, thanks to the conical design of the drill bit loosened soil is forced to the sides of the bit in soft ground, whereat it needs not to be removed from the hole. This procedure works automatically while the bit is advancing. Usually, drilling into soft soil forwards rapidly and produces much removable soil. Since loosend soil is forced mainly aside from the hole, there is hardly any loose soil to be removed. The drilling goes on uninter- tedly without any delays due replacements of the drill bit, which makes the use of this kind of general-purpose drilling apparatus most advantageous.
• Fig. 1 is a section of the drill bit in a drilling apparatus.
• Fig. 2 is the bit viewed from the front.
• Fig. 3 is a section of the drill bit in another drilling apparatus.
• Fig. 4 is the bit viewed from the front.
• Fig. 5 is a section of line B - B of the bit.
• Figure 1 shows the drill head of the drilling apparatus with a hammering machine 1 that strikes a bit assembly 2,3.
• the hammering machine also rotates the bit assembly.
• the bit assembly has an inner bit 2 and around it a ring bit 3.
• the inner bit 2 can be pulled out from the bore while drilling.
• the outer ring bit 3 rests on protective tube 4 pulling it into the hole while drilling.
• Pressure medium mostly compressed air, flows from the hammering machine along channel 8 through the bit to the front side of the bit. This air is guided back through the bit along channels 6, whereby the air flow conveys drill waste along with it.
• buttons 5 fixed to the bit are striking the rock and loosening chips from it, which form the drill waste that is conveyed by means of the air to the rear side of the bit and out from the hole.
• the drill waste is conveyed only partly through channels 6 but is forced due to the conical bit, to the sides of the hole, becoming partly even more compact. Since the bit is both hammering and rotating, loosend soil is easily driven to the sides of the hole.
• Figure 2 is the front side of the bit, where channels 7 and 8 are also visible.
• Figure 3 shows another embodiment of the the bit assembly, where the conical angle OCis smaller, less than 90°' and where there are channels 12 from each step surface.
• the front face must be in the forward direction and not deviate very much from the face perpendicular to the drilling direction. The bit buttons won't stand hitting rock slantingly. Even the stepped conical form is well adaptable to force soft soil aside.
• Figures 4 and 5 show more accurately the position of channels running through the bit.
• grooves 14 are cut directed away from the centre.
• the purpose of these grooves is to grind soil in front of the bit while the bit is rotating and so the soil becomes more loose. Loose soil moves more easily from the front of bit to the sides.
• the openings throuhg the bit are so small that while advancing very fast into soft soil, the loosened soil cannot exit through holes 12 but is easily pushed to the sides.
• the conical angle of the bit can also be less than 70°.
• the cone must not have the same number of degrees all over the bit but the conical shape can vary step-by-step starting from the bit point.

Applications Claiming Priority (3)

Publications (1)

Family

ID=8541503

Family Applications (1)

Country Status (4)

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Family Cites Families (3)

• 1994
  • 1994-10-05 FI FI944640A patent/FI103430B1/fi active
• 1995
  • 1995-10-05 WO PCT/FI1995/000549 patent/WO1996011323A1/en not_active Application Discontinuation
  • 1995-10-05 KR KR1019970702202A patent/KR970706442A/ko not_active Application Discontinuation
  • 1995-10-05 EP EP95934147A patent/EP0784731A1/de not_active Withdrawn

Non-Patent Citations (1)

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