With Dropped Element Patents (Class 175/268)
  • Patent number: 11225849
    Abstract: A cutting tool includes an elongate main body having inlet and outlet ends with a fluid flow path defined therebetween. A piston is mounted within the main body and longitudinally movable with respect to the main body. One or more cutters are moveable between retracted and deployed positions. The piston and each cutter engage one another so that longitudinal movement of the piston with respect to the main body moves each cutter between the deployed position and the retracted position. A flow regulator is operable to divert fluid flowing into the inlet end of the tool selectively along a first path, which passes the through the piston to the outlet end of the tool, and a second path, in which the fluid tends to drive the piston longitudinally with respect to the main body.
    Type: Grant
    Filed: July 12, 2018
    Date of Patent: January 18, 2022
    Inventor: Bruce McGarian
  • Patent number: 10689913
    Abstract: A retractable and extendable roller reamer is positioned on a string. The retractable and extendable roller reamer is configured to support and centralize the string within the wellbore. An extension and retraction mechanism is configured to extend and retract the roller reamer. A hydraulic power unit is configured to control the extension and retraction mechanism. Sensors positioned on or within the roller reamer. The sensors are configured to detect parameters of the well-string stabilizing system. A controller is operatively coupled to the hydraulic power unit and the plurality of sensors. The controller is configured to be positioned in a wellbore. The controller is configured to receive signals from the sensors. The signals represent the parameters detected by the sensors. The controller is configured to identify the parameters represented by the signals. The controller is configured to adjust a well-string stabilizing operation in response to the received signals.
    Type: Grant
    Filed: March 21, 2018
    Date of Patent: June 23, 2020
    Assignee: Saudi Arabian Oil Company
    Inventors: Victor Carlos Costa de Oliveira, Mario Augusto Rivas Martinez, Khaled K. Abouelnaaj, Bader S. Al-Zahrani
  • Patent number: 10519737
    Abstract: A bottom hole assembly (BHA) and methods of using the BHA, the BHA having at least one tool configured to move between the interior and the exterior by fluid pumped down a string. The tool is configured to create a hole in a wellbore tubular, such as casing, tubing, or a liner. The BHA includes a ramp positioned adjacent to the tool to guide the tool to engage the tubular. The tool may be a mill configured to cut a hole in the tubular or a punch member configured to punch a hole in the tubular. A packing element of the BHA enables fluid to be pumped down the annulus and through the hole to treat and/or fracture the formation. The tool may be positioned between two packing elements and fluid may be pumped down the string and through a portion of the tool to treat and/or fracture the formation.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: December 31, 2019
    Assignee: BAKER HUGHES, A GE COMPANY, LLC
    Inventors: Darin H. Duphorne, James Scott Sanchez, André J. Porter
  • Patent number: 10294728
    Abstract: A downhole under-reamer for use in reaming a downhole bore. The under-reamer comprises a body and a plurality of cutters mounted on the body. The cutters are mounted on the body so as to be extendable from a retracted position to at least two extended positions. The at least two extended positions comprise reaming positions at respective first and second reaming diameters.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: May 21, 2019
    Assignee: NOV Downhole Eurasia Limited
    Inventors: Brian Andrew McCarthy, Philip Graham Rodger
  • Patent number: 9945184
    Abstract: A downhole under-reamer for use in reaming a downhole bore. The under-reamer comprises a body and a plurality of cutters mounted on the body. The cutters are mounted on the body so as to be extendable from a retracted position to at least two extended positions. The at least two extended positions comprise reaming positions at respective first and second reaming diameters.
    Type: Grant
    Filed: June 26, 2015
    Date of Patent: April 17, 2018
    Assignee: NOV Downhole Eurasia Limited
    Inventors: Brian Andrew McCarthy, Philip Graham Rodger
  • Patent number: 9587442
    Abstract: An automated locking joint can include a first member, a second member, a joint, a locking structure, and a positioning device. The joint can connect the first member with the second member. The second member can be pivotable about the joint relative to the first member. The locking structure can be positionable between a lock position that prevents pivoting of the second member about the joint and an unlock position that allows pivoting of the second member about the joint. The positioning device can automatically move the locking structure from the lock position to the unlock position or from the unlock position to the lock position.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: March 7, 2017
    Assignee: HALLIBURTON ENERGY SERVICES, INC.
    Inventors: Sean Gregory Thomas, Jack Gammill Clemens
  • Patent number: 9388638
    Abstract: Expandable reamers for enlarging a borehole in a subterranean formation include a tubular body, at least one curved blade track carried by the tubular body, and at least one blade engaged with the at least one blade track and configured to slide along the curved blade track along a curved path between a first retracted blade position and a second expanded blade position. To form such an expandable reamer, a tubular body having at least one curved blade track carried by the tubular body may be formed, and at least one blade may be engaged with the blade track. The blade and blade track may be configured such that the blade slides along the blade track along a curved path between a retracted position and an expanded position. Such expandable reamers may be used to enlarge boreholes in subterranean formations.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: July 12, 2016
    Assignee: Baker Hughes Incorporated
    Inventor: Carl E. Poteet, III
  • Patent number: 9217316
    Abstract: Techniques for correlating depth on a tubular in a wellbore include a casing collar locator tool that includes a tubular mandrel defining a bore therethrough; a top sub-assembly and a bottom sub-assembly carried on the tubular mandrel; a profile carried on the tubular mandrel axially between the top sub-assembly and bottom sub-assembly and adjustable between an engaged state defined by the profile extending radially away from the mandrel and a disengaged state defined by the profile refracted towards the mandrel; and a wedge sleeve carried on the tubular mandrel between the top sub-assembly and the bottom sub-assembly and arranged, at least in part, axially adjacent the profile, the wedge sleeve actuatable to urge the profile into at least one of the engaged state or the disengaged state.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: December 22, 2015
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Muhammad Asif Ehtesham, Robert L. Pipkin, Tim Hunter
  • Patent number: 8960333
    Abstract: Expandable reamers are configured to operate in a first, retracted state in which a plurality of blades is in a retracted position when a sliding sleeve is in a first sleeve position and a seat is in a first seat position, to operate in a second, extended state in which the plurality of blades is movable to an extended position when the sliding sleeve is in at least a second sleeve position and the seat is in the first seat position, and to operate in a third, retracted state in which the plurality of blades is returned to the retracted position when the sliding sleeve is in the at least a second position and the seat is in a second seat position.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: February 24, 2015
    Assignee: Baker Hughes Incorporated
    Inventors: Steven R. Radford, Marcus Oesterberg, S. Richard Gentry
  • Patent number: 8794354
    Abstract: Embodiments of the present invention generally relate to extendable cutting tools for use in a wellbore. In one embodiment, a tool for use in a wellbore includes a tubular body having a bore therethrough, an opening through a wall thereof, and a connector at each longitudinal end thereof; and an arm. The arm is pivotally connected to a first piston and rotationally coupled to the body, is disposed in the opening in a retracted position, and is movable to an extended position where an outer surface of the arm extends outward past an outer surface of the body. The tool further includes the first piston. The first piston is disposed in the body bore, has a bore therethrough, and is operable to move the arm from the retracted position to the extended position in response to fluid pressure in the piston bore exceeding fluid pressure in the opening. The tool further includes a lock operable to retain the first piston in the retracted position; and a second piston operably coupled to the lock.
    Type: Grant
    Filed: January 23, 2013
    Date of Patent: August 5, 2014
    Assignee: Weatherford/Lamb, Inc.
    Inventors: Wei Jake Xu, Albert C. Odell, II, Simon J. Harrall, Thomas M. Redlinger, Christopher M. Vreeland, Andrew Antoine, David J. Brunnert, Tommy L. Laird, Michael J. Moody, Frederick T. Tilton
  • Patent number: 8657039
    Abstract: A downhole apparatus for engaging a borehole in a subterranean formation includes a tubular body having a longitudinal axis and a first bore, an actuation element having a second bore and is positioned within the first bore of the tubular body, a drilling fluid flow path extending through the first and second bores, and a restriction element trap positioned within the second bore of the actuation element. The actuation element is configured to selectively retain an operable component of the downhole apparatus in an initial position and the restriction element trap is configured for retentively receiving a restriction element. A restriction element trap for use with an actuation element for retentively receiving a restriction element and an expandable reamer apparatus for enlarging a borehole in a subterranean formation are also provided. Further provided is a method of activating a downhole apparatus within a borehole of a subterranean formation.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: February 25, 2014
    Assignee: Baker Hughes Incorporated
    Inventors: Steven R. Radford, Kevin G. Kidder
  • Patent number: 8555983
    Abstract: A control mechanism for a downhole tool including a mandrel having a throughbore, at least one activation port, and at least one bypass port, a first sleeve detachably mounted within the throughbore at a first position and moveable to a second position, the first sleeve having a first seat, and a second sleeve detachably mounted within the throughbore at a third position located axially above the first position and moveable to a fourth position, the second sleeve having a second seat. A method of hydraulically actuating and deactuating a downhole tool, the method including disposing the downhole tool and a control mechanism in a well.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: October 15, 2013
    Assignee: Smith International, Inc.
    Inventor: Arturo Palacios
  • Patent number: 8540035
    Abstract: Embodiments of the present invention generally relate to extendable cutting tools for use in a wellbore. In one embodiment, a tool for use in a wellbore includes a tubular body having a bore therethrough, an opening through a wall thereof, and a connector at each longitudinal end thereof; and an arm. The arm is pivotally connected to a first piston and rotationally coupled to the body, is disposed in the opening in a retracted position, and is movable to an extended position where an outer surface of the arm extends outward past an outer surface of the body. The tool further includes the first piston. The first piston is disposed in the body bore, has a bore therethrough, and is operable to move the arm from the retracted position to the extended position in response to fluid pressure in the piston bore exceeding fluid pressure in the opening. The tool further includes a lock operable to retain the first piston in the retracted position; and a second piston operably coupled to the lock.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: September 24, 2013
    Assignee: Weatherford/Lamb, Inc.
    Inventors: Wei Jake Xu, Albert C. Odell, II, Simon J. Harrall, Thomas M. Redlinger, Christopher M. Vreeland, Andrew Antoine, David J. Brunnert, Tommy L. Laird, Michael J. Moody, Frederick T. Tilton
  • Patent number: 8459375
    Abstract: Expandable reamers for enlarging boreholes in subterranean formations include a tubular body and at least one member positioned in openings in the tubular body. The at least one member is configured to move between retracted and extended positions. A push sleeve is disposed at least partially within the tubular body and coupled to the at least one member. The push sleeve moves axially upward to move the at least one member to the extended position in response to a pressure of drilling fluid passing through a drilling fluid flow path in the tubular body. The push sleeve moves axially downward to move the at least one member to the retracted position in response to a pressure of drilling fluid upon a restrictive element disposed within the fluid passageway. The restrictive element disposed within the fluid passageway may be discarded from the fluid passageway by increasing the flow rate through the drilling fluid flow path.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: June 11, 2013
    Assignee: Baker Hughes Incorporated
    Inventor: Steven R. Radford
  • Patent number: 8381837
    Abstract: A downhole tool including a tubular body having an upper connection and a lower connection and an axial borehole therethrough, wherein the upper and lower connections are configured to connect to a drilling assembly, at least one expandable component coupled to the tubular body and configured to selectively extend radially therefrom, and an actuation assembly configured to selectively actuate, deactuate, and reactuate the at least one component. A method of selectively actuating a downhole tool, wherein the downhole tool comprises a tubular body with an axial borehole therethrough and at least one component, the method including circulating a drilling fluid in the axial borehole of the downhole tool, actuating the at least one component, deactuating the at least one component, and reactuating the at least one component.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: February 26, 2013
    Assignee: Smith International, Inc.
    Inventors: Tommy Laird, Richard C. Davis
  • Patent number: 8365842
    Abstract: A tool comprising a fluid path defined by a bore formed within a tubular body includes a guided sleeve and a reciprocating sleeve disposed within the bore. A gearwheel is located on an outer surface of the guided sleeve and at least one pawl located on an inner surface of the reciprocating sleeve. When the reciprocating sleeve translates axially, it rotates in a first direction. As the reciprocating sleeve rotates, the at least one pawl pushes the gearwheel and causes the guided sleeve to rotate in the first direction into a new position.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: February 5, 2013
    Assignee: Schlumberger Technology Corporation
    Inventors: David R. Hall, Scott Dahlgren, Jonathan Marshall
  • Patent number: 8251161
    Abstract: A downhole tool may include a generally hollow piston having a trigger element extending therefrom, the piston configured to slide along an axial cavity extending through a tubular body of the tool. The trigger element may move from a first position where the trigger engages a support on the body and the piston is fixed, to a second position where the trigger disengages and the piston is released. The tool may also include a generally tubular relief sleeve releasably coupled with the piston using a shear pin, while the trigger element is in the first position, and disposed between the trigger and an extension of the piston, to allow the sleeve to slide between the trigger and the extension after shearing of the pin. The piston, sleeve and pin may be configured to allow the sleeve to release from the piston in response to the shearing of the pin.
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: August 28, 2012
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Erik Dithmar, Philippe R Fanuel, Stein Eric Moi, Luis Quintana
  • Patent number: 8205689
    Abstract: Drilling systems and methods for enlarging a borehole that include at least one expandable reamer and at least one expandable stabilizer axially spaced therefrom in a tubular string, such as a drill string, the at least one expandable reamer and the at least one expandable stabilizer being independently actuatable by different-sized actuation devices. A relatively lower tool is actuatable by a smaller actuation device, such as a drop ball, which passes through a relatively higher tool in the drill string without triggering the higher tool.
    Type: Grant
    Filed: May 1, 2009
    Date of Patent: June 26, 2012
    Assignee: Baker Hughes Incorporated
    Inventor: Steven R. Radford
  • Publication number: 20120031673
    Abstract: A downhole tool comprises a body, an extendable cutting member operable to cooperate with a hydraulically actuated cam member, and a cam member lock. The lock is configurable to be activated downhole to restrict movement of the cam member relative to the body and prevent extension of the cutting member.
    Type: Application
    Filed: August 4, 2011
    Publication date: February 9, 2012
    Applicant: NOV DOWNHOLE EURASIA LIMITED
    Inventor: Alan MacKenzie
  • Publication number: 20110232969
    Abstract: A downhole tool including a tubular body having an upper connection and a lower connection and an axial borehole therethrough, wherein the upper and lower connections are configured to connect to a drilling assembly, at least one expandable component coupled to the tubular body and configured to selectively extend radially therefrom, and an actuation assembly configured to selectively actuate, deactuate, and reactuate the at least one component. A method of selectively actuating a downhole tool, wherein the downhole tool comprises a tubular body with an axial borehole therethrough and at least one component, the method including circulating a drilling fluid in the axial borehole of the downhole tool, actuating the at least one component, deactuating the at least one component, and reactuating the at least one component.
    Type: Application
    Filed: March 26, 2010
    Publication date: September 29, 2011
    Applicant: SMITH INTERNATIONAL, INC.
    Inventors: Tommy Laird, Richard C. Davis
  • Patent number: 7975783
    Abstract: In accordance with an embodiment of the present invention, a drilling tool includes a tubular body defining a longitudinal axial cavity extending therethrough and defining at least one cutter element recess. The drilling tool also includes a cutter element at least partially disposed within the at least one cutter element recess and includes at least first and second cutting arms at least substantially disposed within the cutter element recess in a retracted position. The first and second cutting arms are operable to move from the retracted position to an extended position in which the first and second cutting arms extend at least partially beyond a periphery of the tubular body. The first and second cutting arms and the tubular body enclose a space when the first and second cutting arms are in the extended position.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: July 12, 2011
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Philippe Fanuel, Jean-Pierre Lassoie, Olivier Mageren, Luis Quintana, Erik Stein Moi, Erik Dithmar
  • Publication number: 20110155465
    Abstract: An underreamer is provided in which the cutting elements are retracted into the tool body during run in, extensible for the performance of cutting operations, and retractable into the body of the tool afterwards.
    Type: Application
    Filed: December 28, 2009
    Publication date: June 30, 2011
    Inventors: Jerry Allamon, Kevin O. Trahan, Jack Miller, Javier Bolivar
  • Patent number: 7775302
    Abstract: An earth boring bit assembly has a tubular mandrel carried by a casing shoe at the lower end of a string of casing. The casing shoe has stabilizer blades spaced circumferentially apart from each other. A cutter arm seat is formed on the leading edge of each blade at a lower end of the casing shoe. Windows are formed in and spaced circumferentially around the mandrel. A cutter arm is pivotally mounted within each window of the mandrel and movable from an extended position located within one of the cutter arm seats to a recessed position within its window. The cutter arm seats support the cutter arms for torque and axial weight. A sleeve inside the mandrel prevents the cutter arms from pivoting to a recessed position until the sleeve is moved to a released position.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: August 17, 2010
    Assignee: Tesco Corporation
    Inventor: Tommy M. Warren
  • Patent number: 7673708
    Abstract: A ball-activated mechanism adapted to be incorporated in a drillstring and to control the activation, and de-activation of a downhole tool. The mechanism includes a ball seat that receives surface launched activation balls and moves to activate or deactivate the downhole tool, an indexable latching device, and a linearly displaceable actuator co-operable with the indexable latching device, the actuator allowing pressure fluid communication to activate the tool when the actuator is in its activating position. Upon launch of a first activation ball, the ball seat moves so that the latching device carries out indexing movement to a latched position and moves the actuator moves to its activating position so that the downhole tool can be activated. Upon launch of a second activation ball, the latching device undergoes return movement and returns the ball seat to its first position and the actuator moves to deactivate the downhole tool.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: March 9, 2010
    Inventor: Paul Bernard Lee
  • Patent number: 7665545
    Abstract: A method and apparatus for temporarily increasing fluid pressure at a specific location in a work string to perform an operation in an oil or gas well bore. Apparatus is provided which, in a first position provides fluid flow through the work string; in a second position provides the desired increase in fluid pressure to perform the operation in the well bore by dropping a ball (62) into the apparatus; and, by shearing pins (52) to move a sleeve (50) within the apparatus, provides a third position which returns fluid flow through the work string via bypass channels (26) created in the apparatus around the ball. Operation of a pressure activated near bit reamer in conjunction with the apparatus is also described.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: February 23, 2010
    Assignee: Specialised Petroleum Services Group Limited
    Inventor: George Telfer
  • Patent number: 7584811
    Abstract: In accordance with an embodiment of the present invention, a drilling tool includes a tubular body defining a longitudinal axial cavity extending therethrough and defining at least one cutter element recess. The drilling tool also includes a cutter element at least partially disposed within the at least one cutter element recess and includes at least first and second cutting arms at least substantially disposed within the cutter element recess in a retracted position. The first and second cutting arms are operable to move from the retracted position to an extended position in which the first and second cutting arms extend at least partially beyond a periphery of the tubular body. The first and second cutting arms and the tubular body enclose a space when the first and second cutting arms are in the extended position.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: September 8, 2009
    Assignee: Security DBS NV/SA
    Inventors: Philippe Fanuel, Jean-Pierre Lassoie, Olivier Mageren, Luis Quintana, Erik Stein Moi, Erik Dithmar
  • Patent number: 7401666
    Abstract: In accordance with an embodiment of the present invention, a drilling tool includes a tubular body defining a longitudinal axial cavity extending therethrough and defining at least one cutter element recess. The drilling tool also includes a cutter element at least partially disposed within the at least one cutter element recess and includes at least first and second cutting arms at least substantially disposed within the cutter element recess in a retracted position. The first and second cutting arms are operable to move from the retracted position to an extended position in which the first and second cutting arms extend at least partially beyond a periphery of the tubular body. The first and second cutting arms and the tubular body enclose a space when the first and second cutting arms are in the extended position.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: July 22, 2008
    Assignee: Security DBS NV/SA
    Inventors: Philippe Fanuel, Jean-Pierre Lassoie, Olivier Mageren, Luis Quintana, Erik Stein Moi, Erik Dithmar
  • Publication number: 20080128169
    Abstract: A downhole apparatus for engaging a borehole in a subterranean formation includes a tubular body having a longitudinal axis and a first bore, an actuation element having a second bore and is positioned within the first bore of the tubular body a drilling fluid flow path extending through the first and second bores, and a restriction element trap positioned within the second bore of the actuation element. The actuation element is configured to selectively isolate an operable component of the downhole apparatus from exposure to drilling fluid pressure within the tubular body and the restriction element trap is configured for retentively receiving a restriction element. A restriction element trap for use with an actuation element for retentively receiving a restriction element and an expandable reamer apparatus for enlarging a borehole in a subterranean formation are also provided. Further provided is a method of activating a downhole apparatus within a borehole of a subterranean formation.
    Type: Application
    Filed: December 3, 2007
    Publication date: June 5, 2008
    Inventors: Steven R. Radford, Kevin G. Kidder
  • Patent number: 7100713
    Abstract: An expandable reamer shoe is provided for use with expandable casing in a borehole. The reamer shoe has a number of reaming members in the form of blades which remain closed against the body of the shoe when inserted through casing, and can then be expanded to underream below the casing. Additionally, the expandable reamer shoe is made substantially of a drillable material so that the borehole can be extended beyond the point reached by the expandable reamer shoe.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: September 5, 2006
    Assignee: Weatherford/Lamb, Inc.
    Inventor: Rory McCrae Tulloch
  • Patent number: 6443247
    Abstract: A casing drilling shoe adapted for attachment to a casing string and comprising an outer drilling section constructed of a relatively hard material such as steel and an inner section constructed of a readily drillable material such as aluminum. The drilling shoe further includes a device for controllably displacing the outer drilling section to enable the shoe to be drilled through using a standard drill bit and subsequently penetrated by a reduced diameter casing string or liner.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: September 3, 2002
    Assignee: Weatherford/Lamb, Inc.
    Inventor: Michael Wardley
  • Patent number: 6131675
    Abstract: A combination milling and drilling bit which can be converted from a first type of cutting operation to a second type of cutting operation by hydraulically moving a plurality of movable blades to extend beyond a plurality of fixed blades. The fixed blades are dressed with cutting inserts suitable for the first type of cutting operation, while the movable blades are dressed with cutting inserts suitable for the second type of cutting operation.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: October 17, 2000
    Assignee: Baker Hughes Incorporated
    Inventor: James W. Anderson
  • Patent number: 4603749
    Abstract: Downward displacement of an inner tube with respect to the outer tube in a coring tool is effectuated by an apparatus comprising a bearing assembly, a cylinder, a piston telescopically disposed within the cylinder, and a mechanism for selectively applying an hydraulic force to the piston. The bearing assembly is longitudinally fixed with respect to the outer tube while providing rotational freedom with respect to the outer tube. A cylinder is axially disposed within the coring tool, is connected to the bearing assembly, and hence is rotationally free with respect to the outer tube. The piston, which is telescopically disposed within a cylinder, is downwardly longitudinally displaceable within the cylinder, and hence with respect to the outer tube. A mechanism is incorporated within the coring tool for selectively applying a hydraulic force to the piston in order to longitudinally displace the piston downwardly within the cylinder.
    Type: Grant
    Filed: August 27, 1984
    Date of Patent: August 5, 1986
    Assignee: Norton Christensen, Inc.
    Inventors: J. Stanley Davis, Steven R. Radford
  • Patent number: 4177866
    Abstract: A raise boring system is provided for boring raise holes wherein the finished raise holes have portions of different diameters. The system includes a raise head with a central drive stem defining an axis of rotation. Primary cutter means are positioned on the raise head for disintegrating the earth formations out to a first radial distance from said axis of rotation. Expanding secondary cutter means are positioned on the raise head for selectively disintegrating earth formations from said first radial distance out to additional and greater radial distances from said axis of rotation. The expanding secondary cutter means may be selectively located in a first position either beneath or in the same plane as the primary cutter means during boring at said first radial distance from said axis of rotation and selectively located in additional positions for boring at greater radial distances from said axis of rotation.
    Type: Grant
    Filed: May 30, 1978
    Date of Patent: December 11, 1979
    Assignee: Dresser Industries, Inc.
    Inventor: Howard E. Mitchell