Abstract: Disclosed herein is a pneumatic operated hammer for rock drilling, the hammer comprising a cylindrical casing, a back head mounted at an upper portion of the casing, a check valve for opening/closing a compressed air passageway in the casing, a guide for supporting the check valve, a piston adapted to ascend and descend with compressed air in the casing, and a button bit for performing a drilling work through the striking of the piston. The piston is extended to a certain length to conform to the work condition of the pneumatic hammer to thereby prevent a water back-flow phenomenon in which underground water, etc.

Abstract: The present invention relates to a borehole drilling apparatus with in-line extending wings and driving method thereof. The drilling apparatus comprises a guide device rotating while moving upwardly and downwardly in a casing to fit into a borehole, extending wings for extending the diameter of a drilled hole, and a pilot bit installed at a lower portion of the guide device to strike the bottom of the borehole, wherein spiral projections formed at a lower surface of the guide device slidably engage with guide grooves formed at a side of the extending wings to each other, and a window is formed at a side of the pilot bit for advancing and retracting the extending wings so that they can spread and return linearly from the center of the pilot bit.

Abstract: The present invention relates to a borehole drilling apparatus with in-line extending wings and driving method thereof. The drilling apparatus comprises a guide device rotating while moving upwardly and downwardly in a casing to fit into a borehole, extending wings for extending the diameter of a drilled hole, and a pilot bit installed at a lower portion of the guide device to strike the bottom of the borehole, wherein spiral projections formed at a lower surface of the guide device slidably engage with guide grooves formed at a side of the extending wings to each other, and a window is formed at a side of the pilot bit for advancing and retracting the extending wings so that they can spread and return linearly from the center of the pilot bit.

Abstract: Disclosed herein is a pneumatic operated hammer for rock drilling, the hammer comprising a cylindrical casing, a back head mounted at an upper portion of the casing, a check valve for opening/closing a compressed air passageway in the casing, a guide for supporting the check valve, a piston adapted to ascend and descend with compressed air in the casing, and a button bit for performing a drilling work through the striking of the piston. The piston is extended to a certain length to conform to the work condition of the pneumatic hammer to thereby prevent a water back-flow phenomenon in which underground water, etc.

Abstract: Disclosed is a bit striking apparatus in an excavator capable of efficiently striking the entire area of the hammer bit under uniform pressure without exerting excessive load to the excavator so that the hammer bit may be free from damage owing to local concentration of striking force of the piston.

Abstract: Disclosed is a bit striking apparatus in an excavator capable of efficiently striking the entire area of the hammer bit under uniform pressure without exerting excessive load to the excavator so that the hammer bit may be free from damage owing to local concentration of striking force of the piston.

Abstract: Disclosed are bisaminothiol and amino compounds with appended pharmacophores, complexes of these compounds with .sup.99m Tc(V)0, Re(V)0, In.sup.+3, .sup.67 Ga.sup.+3, .sup.90 Y.sup.+3, .sup.109 Pd.sup.+2 or .sup.105 Rh.sup.+3, and pharmaceutical compositions containing the complexes. Also disclosed are methods of diagnosing a mammal for the presence of a mammalian tumor, methods for in vitro detection of a cancer cell in a mammalian tissue sample, and methods of treating a mammal having a tumor.