With Means To Couple Members To Prevent Relative Rotation Patents (Class 175/306)
  • Patent number: 9004196
    Abstract: A drill bit assembly has a bit head and a pin body. The bit head comprises a cutting end, an opposite connecting end with an engagement section, and a feature facing the connecting end. The pin body comprises a tubular body with an axial bore therethrough, a connecting end with an engagement section and a feature facing the connecting end. The drill bit assembly is manufactured by positioning the pin body connecting end with the bit head connecting end such that the pin body and bit head engagement sections overlap with a gap therebetween, and the pin body and bit head features are aligned; injecting a thermoplastic or other connecting material in liquid form between the bit head and pin body engagement sections and into the gap; and solidifying the thermoplastic or other connecting material such that the bit head and pin body are mechanically coupled together at their connecting ends and their features are securely aligned.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: April 14, 2015
    Assignee: Schlumberger Technology Corporation
    Inventors: Kjell Haugvaldstad, Derek Logan, Garry Holmen, Tony R. Dopf, Aaron Logan, Rob Utter
  • Patent number: 8910729
    Abstract: An apparatus for drilling a hole in the ground has a hammer drill installed at a bottom of a rod assembled in multi-stages at support structure on the ground. The hammer drill has a pilot hammer drill and a reamer hammer drill coupled to each other through a key structure formed in the vertical direction so as to allow simultaneous rotations and up-and-down movements relative to each other.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: December 16, 2014
    Assignee: Core Geotechnics Co., Ltd.
    Inventor: Sun Keun Park
  • Patent number: 8657040
    Abstract: A percussion drilling assembly includes an outer tubular, an inner tubular coupled within the outer tubular at a threaded region, a drill bit slideably disposed within the inner tubular, and a locking system located proximate the threaded region. The locking system is actuatable by translation of the drill bit relative to the locking system, whereby the locking system is configured to prevent rotation of the inner tubular relative to the outer tubular in at least a first direction.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: February 25, 2014
    Assignee: Smith International, Inc.
    Inventors: Alan Jackson Marshall, Shantanu Swadi, James A. Simson
  • Patent number: 8397839
    Abstract: A down-the-hole drill (DHD) hammer having a casing, a drill bit proximate a distal end of the casing, a piston mounted within the casing and a self-indexing drive transmission is provided. The piston includes a plurality of helical and axial splines. The drive transmission includes a driver sleeve, a driven sleeve and a wrap spring clutch assembly. The driver sleeve and driven sleeve are housed within the casing and circumscribes the piston. The driver sleeve includes a plurality of openings for receiving a plurality of bearings. The driver sleeve bearings are configured to operatively engage the helical splines on the piston. The wrap spring clutch assembly includes a wrap spring circumscribing the driver sleeve and driven sleeve. The driven sleeve operatively engages the drill bit to rotationally index the drill bit.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: March 19, 2013
    Assignee: Center Rock Inc.
    Inventor: Leland H. Lyon
  • Patent number: 8381843
    Abstract: A well bore reamer has an elongated body for coupling between members of a well string, a first set of cutting elements on the body at a fixed position, a second set of cutting elements on a sleeve closing around a sleeve carrying portion of the elongated body. The sleeve is slidable along a longitudinal axis of the body and rotatable thereabout. A lower clutch mechanism operates between the sleeve and the elongated body at a bottom end of the body's sleeve carrying portion to block rotation of the sleeve relative to the elongated body in a predetermined direction about the longitudinal axis under sliding of the sleeve into a lowered position adjacent said bottom end of the sleeve carrying portion.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: February 26, 2013
    Inventor: Bradley Allan Lamontagne
  • Patent number: 7997346
    Abstract: A percussion drilling assembly for boring into the earth. In an embodiment, the assembly comprises a tubular case having a central axis and a lower end. In addition, the assembly comprises a driver sub having an upper end threadingly engaged with the lower end of the case. Further, the assembly comprises a annular locking member disposed about the driver sub. The annular locking member engages the case and the driver sub and restricts the rotation of the driver sub relative to the case about the central axis.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: August 16, 2011
    Assignee: Smith International, Inc.
    Inventor: Alan J. Marshall
  • Patent number: 7987930
    Abstract: The invention relates to a drill bit assembly for fluid-operated percussion drill tools comprising a percussion bit (1) having a head portion (3) formed with an axially extending stub shank (32). The stub shank is provided with axially extending splines (36), which are slideably engageable with complementary splines (35) formed on a drive chuck (4). Rotational drive from the chuck (4) may be transmitted to the stub shank (32) by means of the splines. Bit retaining means (6, 7, 41, 42) at the chuck are adapted for engagement with complementary retaining means (37, 51) at a spline portion of the stub shank to retain the stub shank in the drill bit assembly. Engagement means on the chuck (4) are adapted for connecting the chuck (4) to a drive means (5) of the fluid-operated percussion drill tool.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: August 2, 2011
    Assignee: Minroc Technical Promotions Limited
    Inventor: Joseph Purcell
  • Patent number: 7975784
    Abstract: A drill bit assembly for fluid-operated percussion drill tools. The assembly comprises a percussion bit (1) having a head portion (3) formed with an axially extending stub shank (32). A drive bush (2) is releasably connectable to the bit head portion (3). Axially extending splines (35) on the drive bush (2) are slideably engageable with complementary splines (36) formed on a drive chuck (4) whereby rotational drive from the chuck (4) may be transmitted to the drive bush (2). The assembly further comprises engagement means on the chuck (4) adapted for connecting the chuck (4) to a drive means (5) of the fluid-operated percussion drill tool.
    Type: Grant
    Filed: January 4, 2007
    Date of Patent: July 12, 2011
    Assignee: Minroc Technical Promotions Limited
    Inventor: Joseph Purcell
  • Patent number: 7882906
    Abstract: A drilling and vibratory jarring device is provided. The device has an inner mandrel shiftable upward or downward in an outer housing from an intermediate position in the outer housing. When the inner mandrel is in the intermediate position within the outer housing mating splines, one set of splines attached to inner mandrel, the other set of splines attached to the outer housing, engage and rotatably lock inner mandrel and outer housing together. When the inner mandrel is shifted to the upward position said splines disengage and the saw-tooth surfaces of an upper pair of jars engage creating longitudinal vibratory forces down-hole when inner mandrel is rotated with respect to outer housing. When the inner mandrel is shifted to the downward position said splines disengage and the saw-tooth surfaces of an lower pair of jars engage creating longitudinal vibratory forces down-hole when inner mandrel is rotated with respect to outer housing.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: February 8, 2011
    Inventor: Perry Joseph DeCuir, Sr.
  • Patent number: 7866416
    Abstract: A downhole tool string, comprising a tool string bore and a drill bit located at the bottom of the tool string. The drill bit comprises a body intermediate a shank and a working surface. The working surface may comprise a substantially coaxial rotationally isolated jack element with a portion of the jack element extending out of an opening formed in the working surface to engage a subterranean formation. The tool string may comprise a driving mechanism adapted to rotate the jack. The clutch assembly disposed within the tool string bore may comprise a first end in communication with the jack element and second end in communication with the driving mechanism.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: January 11, 2011
    Assignee: Schlumberger Technology Corporation
    Inventors: David R. Hall, David Lundgreen
  • Patent number: 7234544
    Abstract: In a tool having an inner member supported within an outer member, wherein the tool defines a longitudinal axis, a device is provided for preventing relative rotation of the inner member and the outer member. The device is comprised of a locking mechanism and a locking actuator. The locking mechanism is positioned between the inner member and the outer member, wherein the locking mechanism is movable longitudinally between a first locking mechanism position in which the inner member and the outer member are disengaged and capable of relative rotation and a second locking mechanism position in which the inner member and the outer member are engaged and not capable of relative rotation. The locking actuator causes the locking mechanism to move longitudinally.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: June 26, 2007
    Assignee: Halliburton Energy Services, Inc.
    Inventor: Gerald Edward Kent
  • Patent number: 7017682
    Abstract: A valve assembly connects into a drill string for opening and closing a passage within the drill string. The valve assembly has an inner valve member for opening and closing an inner passage of the drill string. The valve member moves between the open and closed positions in response to axial movement of the drill string. Lifting the drill string causes the upper portion to move upward relative to the lower portion, bringing along with it the valve member, while the valve sleeve remains stationary with the lower portion, opening the valve. The valve assembly can include an annular valve assembly for opening and closing an annular passage located around the inner passage. The annular valve assembly is opened and closed by increasing the pressure in the annular passage above the annular valve assembly.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: March 28, 2006
    Assignee: Vetco Gray Inc.
    Inventors: Kwong-Onn C. Chan, Behrooz Movaffagh, Xiaoping He, Loren Pierre Boisvert
  • Patent number: 6981560
    Abstract: A method and apparatus for delivering a well treatment fluid to a productive zone of a subterranean formation at the same time that a well bore is being drilled is provided. The method includes the steps of delivering a drill-in fluid to a drill bit drilling a well bore in, or adjacent to, the productive zone; removing drill cuttings from the well bore; and simultaneous with these steps injecting the treatment fluid into the productive zone. The apparatus includes at least three nested tubes, which form one internal flow path and two annuluses. The drill-in fluid and drill cuttings are delivered to, and removed from, the drill bit, respectively, through the internal flow path and one of the two annuluses. The treatment fluid is delivered to the subterranean formation through the remaining annulus and an expandable bladder mounted to the intermediate and outer tubes.
    Type: Grant
    Filed: July 3, 2003
    Date of Patent: January 3, 2006
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Philip D. Nguyen, Michael Sanders
  • Patent number: 6896060
    Abstract: A downhole jarring apparatus including a shaft and a first mandrel configured to releasably engage, a collar operatively attached to the shaft such that an axial position of the collar relative to the shaft is adjustable by access through an opening in an outer surface of a second mandrel, and an energy store configured to exert a force against the shaft, wherein the force is adjustable in response to the axial position of the collar relative to the shaft.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: May 24, 2005
    Assignee: Impact Selector, Inc.
    Inventor: Ray O. Tillett, Jr.
  • Patent number: 6866096
    Abstract: According to the present invention, the e-line downhole jarring tool is an electrical line downhole tool for manipulating a work string which is easily configured to deliver a specific amount of force to the work string in a small and simple apparatus.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: March 15, 2005
    Assignee: Impact Selector, Inc.
    Inventor: Ray O. Tillett, Jr.
  • Patent number: 6745836
    Abstract: The down hole motor is a self-contained radial drive unit that is driven by a linear input, which can be supplied from various sources. As linear motion is applied to the input of the tool, drive pins on a drive shaft follow a helical path, converting the linear motion into radial motion at the attached mandrel end. This may then be utilized in various activities such as drilling, boring and obstruction removal. This tool may also be used in conjunction with jarring mechanisms in order to create an impact drilling device, or a percussion motor.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: June 8, 2004
    Inventors: Jeff L. Taylor, Mark A. Taylor
  • Patent number: 6705415
    Abstract: In a directional drilling apparatus in which a sensor/transmitter or sonde is located in one section of a drill string and an element of an adjacent section is configured to “steer” the bore drilled in a predetermined lateral direction, a device is provided for automatically ensuring correct registry or alignment of the sensor/transmitter and the steerable element, this device comprising an azimuth member on the section carrying the sensor/transmitter engageable with a reference member of the adjoining section to present, after such engagement, relative rotation of the azimuth member, which is rotatable in the section carrying it, with the sensor/transmitter, but non-rotatably connected with the sonde. The reference member or the azimuth member is resiliently displaceable axially to allow the two sections to be screwed up together.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: March 16, 2004
    Assignee: Halco Drilling International Limited
    Inventors: Alistair Michael Falvey, John Willoughby Gartside
  • Patent number: 6702040
    Abstract: A telescopic drilling method includes the steps of drilling an outer bore through a surface, inserting a hollow outer conduit into the outer bore, and at least partially inserting a first hollow inner conduit through the outer conduit. Next, the method includes the steps of preventing the first inner conduit from moving longitudinal with respect to the outer conduit engaging a rotatable inner drill bit with a ring drill bit and further drilling the outer bore using a unitary drill bit head to a successive depth. The inner drill bit is disengaged from the ring drill bit and a second end of a successive hollow inner conduit is attached to a first end of a preceding one, and the preceding inner conduit is unclamped.
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: March 9, 2004
    Inventor: Floyd R. Sensenig
  • Patent number: 6516903
    Abstract: A stabilizing sleeve device for an impact drill bit used in underground drilling operations. The cylindrical tubular device has arcuate keys on a bottom edge for interlocking with keyways in the shoulder of a hammer drill bit and a locking key groove in its top edge.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: February 11, 2003
    Assignee: Weatherford/Lamb, Inc.
    Inventor: Cody H. Rogers
  • Patent number: 6397957
    Abstract: A jacket tube for a device for drilling holes and forming an anchorage in the earth or rock. The jacket tube is coupled with a drill pipe and/or a drill bit or a drill hammer and is configured with a plurality of through openings across its periphery. Once the borehole has been made, or after an anchor has been introduced, the jacket tube can be filled with a hardenable suspension. The jacket tube consists of at least one expanded metal element which has evenly distributed through openings and connecting elements, especially sleeves, at the ends for connecting to a drill bit and/or other jacket tube elements. The borehole is therefore easy to produce and the jacket tube can be anchored securely.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: June 4, 2002
    Assignees: Techmo Entwicklungs-und Vertriebs GmbH, “ALWAG” Tunnelausbau Gesellschaft m.b.H.
    Inventors: Josef Mocivnik, Karl Bohm
  • Patent number: 6357538
    Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, may be a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.
    Type: Grant
    Filed: December 6, 2000
    Date of Patent: March 19, 2002
    Assignee: Baker Hughes Incorporated
    Inventor: Gordon A. Tibbitts
  • Patent number: 6182774
    Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, may be a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.
    Type: Grant
    Filed: October 14, 1998
    Date of Patent: February 6, 2001
    Assignee: Baker Hughes Incorporated
    Inventor: Gordon A. Tibbits
  • Patent number: 6082457
    Abstract: A method of operating a drill string tool for use in a wellbore formed in an earth formation is provided. T he method comprises rotating an upper drill string part while a rotation transfer assembly transfers the rotation of a first element to a second element so as to rotate a lower drill string part in order to drill a section of a wellbore, inducing a controller to disengage the rotation transfer assembly so as to allow the first element to rotate relative to the second element by virtue of bearings, and rotating the upper drill string part about its longitudinal axis while the lower drill string part remains substantially stationary.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: July 4, 2000
    Assignee: Shell Oil Company
    Inventors: Bruno Best, Markus Antonius Van Buren
  • Patent number: 5947214
    Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, maybe a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: September 7, 1999
    Assignee: Baker Hughes Incorporated
    Inventor: Gordon A. Tibbitts
  • Patent number: 5778993
    Abstract: A common problem with reverse circulation downhole hammers is retention of the sample tube that extends through the actual hammer component., There is a tendency for the sample tube to become loose in its mounting, and the resulting movement through vibration results in accelerated wear which rapidly leads to failure of the component In this application, the sample tube for use in a reverse circulation downhole hammer comprises a sample tube that has a lower end connected to a drill bit sample delivery aperture and an upper end connected to a drill string sample delivery tube. The sample tube has at least one projection intermediate the upper and lower ends of the sample tube that has a non-circular cross section extending radially from the sample tube. The projection locates within a recess that has a corresponding cross sectional shape, the recess being fixed with respect to the hammer to prevent rotation of the sample tube with respect to the hammer.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: July 14, 1998
    Assignee: SDS Pacific PTE, Ltd.
    Inventor: Frederick Graham Moir
  • Patent number: 5407021
    Abstract: A down-the-hole hammer drill having a reverse circulation system which conducts pressurized air downwardly to a lower cutting face of a drill bit. The air travels across the cutting face and upwardly through a central exhaust passage. The air is conducted to the cutting face through longitudinal and lateral passages in the bit which are kept isolated from the environment surrounding the bit so that no appreciable amount of pressurized air can escape, and so that the passages do not become clogged with dirt. The drill bit comprises upper and lower pieces. Upper sections of the longitudinal passages are formed in the upper piece, and lower sections of the longitudinal passages are formed in the lower piece.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: April 18, 1995
    Assignee: Sandvik Rock Tools, Inc.
    Inventors: Robert F. Kane, Matthew Shofner, Faisal J. Yousef, Kenneth Ahlhorn
  • Patent number: 5010965
    Abstract: In a self-propelled ram boring machine, in particular for making earth bores, having a striking tool at the leading end of a cylindrical housing, a striking piston movable to subject said striking tool to ramming blows, said striking piston being driven with pulsating, translatory working strokes, the striking tool is mounted in the housing to rotate about the axis of rotation and comprises kinematic means cooperating with the housing to change a translatory movement following each blow of said striking piston into a gradual rotary movement, and pneumatically operable means for initiating or interrupting the rotary movement.
    Type: Grant
    Filed: April 4, 1990
    Date of Patent: April 30, 1991
    Assignee: Tracto-Technik Paul Schmidt Maschinenfabrik KG
    Inventor: Robert Schmelzer
  • Patent number: 5005656
    Abstract: Device in impact machines. The device comprises a number of rods (6) provided with projections (51). The rods are journalled in a surrounding set of tubes (7) by means of elastic bushings (52,53) which are provided with grooves (57) through which said projections can be passed.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: April 9, 1991
    Assignee: Atlas Copco MCT AB
    Inventor: Jorgen A. R. Rodert
  • Patent number: 4745983
    Abstract: The present invention relates to a seat protector device of the type which may be employed with drill rods for transmission of thrust from a driving member to a driven member. More specifically, the invention relates to an improved drill rod system for earth drilling where the rod also provides an axial passageway for a fluid to carry drill cuttings away from the cutting area. The seat protector device of the present invention may be detachably inserted between one or more drill rod sections and/or between one of the drill rods and the drill bit and/or between one of the drill rod members and the driving chuck for transmitting thrust load forces while simultaneously reducing damage and/or wear between the component parts.
    Type: Grant
    Filed: December 17, 1986
    Date of Patent: May 24, 1988
    Assignee: Sandvik Rock Tools, Inc.
    Inventors: John L. Moorehead, Ray H. Shaw
  • Patent number: 4665998
    Abstract: A mechanical well jar is disclosed having inner and outer tubular members movable longitudinally relative to each other a limited distance for connecting in a pipe string. Annular shoulders on the members engage to limit the relative longitudinal movement of the members. A plurality of laterally spaced, arcuate cam plates are attached to the inner surface of the outer member. Each plate has a laterally extending U-shaped notch opening into the space between the plates and formed with curved outwardly flaring sidewalls. Rollers are mounted on the outer surface of the inner member to extend into the spaces between the cam plates for movement into the U-shaped notches to hold the members from longitudinal movement relative to each other.
    Type: Grant
    Filed: January 31, 1985
    Date of Patent: May 19, 1987
    Assignee: Eastman Whipstock, Inc.
    Inventor: Clifton A. Burton
  • Patent number: 4573536
    Abstract: A method and apparatus for flushing a well involves the use of a tool which enables a certain jarring displacement to cause a flush valve to be opened. Rotary oscillation of a stem in a given direction may be converted by a ratchet mechanism into rotation of a sleeve in the same direction. The stem may oscillate in either of two rotary directions but rotation in only one direction is transferred to the sleeve. In addition, the ratchet mechanism may be arranged so that rotation of the stem by a given amount results in rotation of the sleeve by a lesser amount. The rotation of the sleeve may be converted into a reciprocating motion of a valve portion through a cam-like engagement between the sleeve and the valve portion. The valve portion includes a port which is capable of communicating with a port in the barrel in response to a predetermined extent of displacement along the longitudinal axis of a drill string.
    Type: Grant
    Filed: November 7, 1984
    Date of Patent: March 4, 1986
    Assignee: Dailey Petroleum Services Corporation
    Inventor: James D. Lawrence
  • Patent number: 4452307
    Abstract: A reamer for removing paraffin, scale, ice and other accumulations from the inside surfaces of oil well pump tubing and casing and loosening tubing in a well, which includes a hollow shell or housing having a tapered base, which in a preferred embodiment is fitted with external blades for cutting, the reamer further provided with an enlarged upper internal bore area to accommodate a threaded lock nut, and a threaded shaft projecting into the housing cavity in threadable cooperation with the lock nut and provided with stops to permit limited rotation of the housing and base on the shaft and to prevent the shaft from exiting the housing when fully extended from the housing on the lock nut. When the reamer is lowered by means of a wire line and swivel joint into a length of tubing or casing to a constricted area and the shaft is extended from the housing, a repetitive impact load on the projecting end of the shaft effects rotation of the housing and base, and the blades cut into and remove the deposits.
    Type: Grant
    Filed: October 29, 1981
    Date of Patent: June 5, 1984
    Inventor: Gary B. Horton
  • Patent number: 4408670
    Abstract: A sub assembly to be inserted between a drill string and a bit has a stabilizer sleeve to engage the walls of a bore hole and hold a first cam against rotation. A second cam is fixed to a drill holder at the lower end of the assembly and is driven in rotation by a rotary driving member extending through the assembly. The cams interengage so that relative rotation between them applies periodic impacts to the drill holder.
    Type: Grant
    Filed: April 24, 1981
    Date of Patent: October 11, 1983
    Inventor: William N. Schoeffler
  • Patent number: 4210316
    Abstract: A shock absorbing apparatus for use in an earth boring drill string is disclosed herein. The shock absorber is of the type having a mandrel reciprocally mounted for rotation with a tubular body; a sealed chamber between the tubular body and the mandrel containing pressurized fluid for absorbing load and shock. Torque is transmitted between the mandrel and body by pins which are inserted in cavities formed by grooves on the exterior of the mandrel and the interior of the body. Means are provided to prevent pin rotation and to prevent the pins from contacting the groove edges to provide improved loading and wearing characteristics of the pins.
    Type: Grant
    Filed: January 29, 1979
    Date of Patent: July 1, 1980
    Assignee: Hughes Tool Company
    Inventor: James R. Hall