| 摘要 |
<p>DRILL HAMMER WITH VARIABLE AIR CONSUMPTION A drill hammer which utilizes pressurized air for reciprocating a piston to provide a percussive drilling force to the drill bit is shown. The hammer includes a cylindrical housing having a top sub-member threadedly received therein for mating with the drill string. The housing also defines a chamber enclosing the reciprocal piston between an upper member and the axially lower drill bit. A spacer member is releasably attached to the upper member and within the chamber to displace a predetermined volume of said chamber. Spacer members of various volumes are provided to thereby vary the volume of the chamber in accordance with desired air consumption for the hammer. Removal of the top sub permits withdrawal from the chamber of the top member and spacer member which are maintained together by a removable pin, permitting the spacers to be readily changed in the field for altering the consumption characteristics as dictated by drilling conditions or other variables in the field.</p> |
