| 摘要 |
A pressure fluid actuated downhole percussion tool includes a reciprocating piston hammer with differential transverse pressure surfaces cooperable with a cylinder housing, a guide sleeve and a bit carried exhaust tube to form opposed pressure fluid chambers to which pressure fluid may be conducted to deliver repeated impact blows to a bit having circumferentially spaced bosses and replaceable cutting inserts. The bit is drivenly connected to the tool by plural drive pins supported in circumferentially spaced grooves in the bit shank and in a removable sub supported by the tool housing. Improved earth penetration performance is realized utilizing a claw bit with a pressure fluid actuated percussion tool providing rotation as well as selective deliverance of impact blows through the bit.
|
