DRILLING DEVICE

摘要

A drilling device for a down-the-hole drilling apparatus. The drilling device includes in a guide, a drilling member and a flushing mechanism configured to flush drilling waste. The drilling mechanism includes first and second drilling bit arrangements that are movable with respect to the drilling device and that are arranged to be expanded to drill a hole having a greater cross-sectional surface area than an end of the casing and arranged to be reduced to a size smaller than the end of the casing. Bit pieces of the second drill bit arrangement expand and reduce the second drill bit arrangement. The bit pieces expand the second drill bit arrangement by moving in a radial direction outwards in slide grooves, by rotating the guide in a drilling direction, and move in the radial direction inwards in the slide grooves, by rotating the guide in an opposite direction.

主权项

1. A drilling device that is meant to be used in a down-the-hole drilling apparatus for drilling a hole by using the drilling device and a casing part and a hammering device when needed, the drilling device comprising:
in a drilling head thereof a guide, a drilling member, and a flushing arrangement configured to flush drilling waste being generated, whereby the drilling member comprises a first drill bit arrangement and a second drill bit arrangement that is movable with respect to the above, whereby the drill bit arrangements comprise drilling organs, wherein the second drill bit arrangement is arranged to be expanded for drilling a greater hole than a free cross-sectional surface area of an end of the casing part and to be reduced to a smaller size than the free cross-sectional surface area of the end of the casing part in order to make possible removal of the drilling device from a hole that has been drilled and for leaving the casing part in the drilled hole by removing the drilling device through the casing part from above, whereby the second drill bit arrangement comprises at least two bit pieces that are movable in radial direction on a drilling surface of the drilling member, and in which the drilling organs are arranged when viewed in a longitudinal direction of the drilling device on the front surface thereof, wherein the bit pieces of the second drill bit arrangement are arranged, for expanding/reducing of the second drill bit arrangement utilizing the guide, movable in slide grooves that pass wide open in the radial direction on the drilling surface of the drilling member for expanding the second drill bit arrangement by moving its bit pieces in the radial direction outwards in the slide grooves, by rotating the guide in one direction in a drilling direction, and for reducing the second drill bit arrangement by moving its bit pieces in the radial direction inwards in the slide grooves, by rotating the guide in an opposite direction, wherein the slide grooves of the bit pieces of the second drill bit arrangement are arranged either in an auxiliary frame, wherein the first drill bit arrangement is arranged in an immovable manner in connection with the guide, or in an intermediate frame, wherein the first drill bit arrangement is in connection therewith, the frame being coupled with the guide rotatively in a restricted manner in a crosswise plane.