Fluid operated drilling device and a method for drilling a hole
AssigneePirkan Laatupalvelu Oy
InventorJuhani VÄLISALO
Life of this patent
Estimating the term…
Abstract
A fluid operated drilling device for drilling a hole includes a hammer connected to a drill rod, and a rotation device to rotate the drill rod and the hammer. The hammer includes a tubular main body, a back head, a cylindrical piston housing, a reciprocating piston and a space between the piston. The piston housing is divided by an annular pressurizing portion into first and second space portions for elevating and striking the piston. First communication channels from a hollow portion of the piston into a second space between the piston and the main body discharge fluid between the piston and the main body. A method for drilling a hole using the fluid operated drilling device is also disclosed.
Claims21
A fluid operated drilling device for drilling a hole, the drilling device comprising:
- a hammer for creating the hole with a rotating and percussive motion;
- a drill rod connected to the hammer;
- and
- a rotation device connected to the drill rod for rotating drill rod and the hammer, and transporting operating pressurized drill fluid through the drill rod to the hammer for creating the percussive motion of the hammer, the hammer comprising:
- a tubular main body having a hollow interior and an upper end and a lower end;
- a back head, for connecting the hammer to the drill rod, coupled to the upper end of the main body and having a fluid pressure supply passage;
- a cylindrical piston housing connected to the main body;
- a reciprocating piston slidably installed in the piston housing for impacting a drill bit of a bit unit installed at the lower end of the main body, the drill bit being movable for a predetermined length longitudinally relatively to the main body, the piston having a first end and a second end, the first end being closer to the drill rod than the second end, a hollow portion through which operating fluid is discharged, a first communication hole connected to the hollow portion and an annular pressurizing portion protruding on an outer circumferential surface of the piston;
- a space between the piston and the piston housing divided by the annular pressurizing portion extending in a radial direction of the piston into a first space portion for elevating the piston and a second space portion for striking the piston,
- a second space in the hollow interior of the main body between the piston and the main body in the radial direction of the piston and between the piston housing and the bit unit in axial direction of the piston;
- first communication channels from the hollow portion of the piston into the second space for discharging the fluid between the piston and the main body;
- a valve unit for controlling fluid discharge from the second space portion through the first communication hole to the hollow portion, and;
- a fluid pressure supply unit for supplying high pressure fluid delivered to the fluid pressure supply passage of the back head alternately to the first space portion and the second space portion;
- wherein the rotating device rotates the bit unit using the drill rod and the main body.
(canceled)
A method for drilling a hole using a fluid operated drilling device, which method includes steps of
- pressurizing pressurized operating fluid with a fluid pressure supply unit;
- rotating a drill rod and a percussive hammer attached to the drill rod with a rotation device,
- leading pressurized operating fluid to a percussive hammer through the drill rod;
- using pressurized operating fluid in the percussive hammer to alternately elevate and impact a percussive piston by pressurizing a first space portion inside a piston housing to elevate the piston and second space portion inside the piston housing to impact the piston to cause the percussive motion of a drill bit installed axially movably on the piston;
- guiding operating fluid discharged from the first space portion and the second space portion outside the piston to flush and lubricate a hollow interior of a main body between the piston and the main body of the hammer outside the piston housing, and
- guiding operating fluid discharged to the hollow interior back inside the piston before guiding the operating fluid through a bit unit.
Dependencies are inferred from the claim text.