Patent ID: 6467554
Filing Date: 2002-10-22
Classification: E21B

Abstract:
An impact-operated, ground-penetrating tool powered by a primary supply of pressurized fluid, and controlled between a forward operating mode and a reverse operating mode by a second supply of pressurized fluid, the tool comprising:a housing having a front end, a rear end, and body defining an interior operating chamber with an inner surface, an exhaust conduit providing communication between the operating chamber and the outside of the tool, a forward striker surface, and a rearward striker surface; a striker reciprocally supported within the operating chamber of the housing between the forward and rearward striker surfaces, the striker having a forward end, a rear portion terminating in a rear end, and a striker body defining an interior striker chamber, wherein the rearward portion sealingly engages the inner surface of the operating chamber to divide the operating chamber into a forward operating chamber and a rearward operating chamber, the rearward operating chamber continuous with the exhaust conduit, wherein the striker body has at least one striker port to provide fluid communication between the forward operating chamber and the interior striker chamber; a manifold near the rear end of the housing and comprising a primary conduit connectable to the primary fluid supply and a secondary conduit connectable to the secondary fluid supply; a primary fluid inlet tube extending from the primary conduit of the manifold; a valve chamber in fluid communication with the secondary conduit in the manifold; a control sleeve having a rear portion, a front portion, and an interior sleeve chamber defining a passage between the rear portion and the front portion, wherein the front portion is slidably and sealingly supported inside the rear portion of the striker, wherein the rear portion is slidably and sealingly supported on the primary fluid inlet tube at least partially inside the valve chamber, whereby the sleeve provides continuous fluid communication between the primary fluid inlet tube and the striker chamber, so that in response to a supply of primary fluid the striker reciprocates between a forward position in which the striker port is open between the interior striker chamber and the forward operating chamber and a rearward position in which the striker port is open between the forward operating chamber and the rearward operating chamber and exhaust conduit; a primary fluid inlet tube extending from primary conduit of the manifold a distance into the interior sleeve chamber of the control sleeve; and wherein the rear portion of the sleeve includes a nodular lobe inside the valve chamber movable between a forward position in response to pressurization of the valve chamber and a reverse position in response to depressurization of the valve chamber, so that the forward portion of the sleeve moves between a forward position in which the striker hits the forward striker surface as it reciprocates and a rearward position in which the striker hits the rearward striker surface as it reciprocates.