| 摘要 |
An expandable downhole tool apparatus is disclosed. The apparatus comprises a body adapted to be incorporated into a drill string and at least one working member moveable relative to the body between an inward deactivated position and an outwardly deployed activated position in order to engage the wall of a borehole. Activation means adapted to move at least one said working member between the inward deactivated position and outwardly deployed activated position is provided. At least one passage is formed through the body and extends from a location on the body adjacent at least one working member to a location remote from the respective working member to enable debris accumulating underneath the respective working member to move along the passage and exit the body. |
