Abstract: Disclosed herein are embodiments of a pressure compensation piston and embodiments of rotary seal assemblies. In one embodiment, a pressure compensation piston for use with a rotary seal assembly includes a stepped piston having an opening extending there through for positioning the stepped piston about a rotatable shaft of a rotary seal assembly. In accordance with this embodiment, the pressure compensation piston further includes a rotary seal positioned along a radial surface of the opening for sealing the stepped piston relative to the rotatable shaft.

Abstract: An earth boring bit with sealed cutter bearings has a dual function pressure compensator for a lubricant reservoir. The earth boring bit has a bit body and downwardly extending legs which include bearing shafts that extend inward and downward for mounting rotary cutters, and seals are provided between the bearing shafts and the cutters. Lubricant flow passages extend from an interior cavity of the bit body, through the legs and the bearing shafts, and into the spaces located between the bearing shafts and the cutters. The pressure compensator extends between the cavity and the flow passages and has a movable piston. The compensator may be operated in a sealed lubricant system mode when the piston is locked in place or an air flow bypass mode by removing a locking member from securing the piston in place prior to securing the earth boring bit to a drill string.

Abstract: A sensor transportation apparatus for conveying a sensor assembly through a wellbore comprises at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly, at least one axle, a bearing connected to the axle, and a wheel connected to the bearing and provided with a shaft seal to prevent or reduce debris from the wellbore entering the bearing, and a lubrication delivery system to provide a lubricant to the bearing at a pressure which is greater than ambient wellbore pressure. The lubrication system comprises a bellows formation, and the apparatus comprises a housing to contain the lubricant, the housing in fluid communication with the bearing, the bellows formation sealingly mounted to the housing with at least a portion of the bellows received within the housing.

Abstract: At least one mechanical face seal is disposed within a cutter cartridge of a roller reamer. The cutter cartridge includes a roller cutter and a retention assembly. A bearing shaft of the retention assembly extends through an inner channel of the roller cutter. A first mechanical face seal is disposed or shared between the roller cutter and a first pillow block of the retention assembly. An optional second mechanical face seal is disposed or shared between the roller cutter and a second pillow block of the retention assembly. Each pillow block is rotatably coupled at an opposing end of the bearing shaft. The retention assembly includes two separately matched sets of one pillow block and a wedge. The wedges in combination detachably secure the pillow blocks to a tool body of the roller reamer.

Abstract: At least one labyrinth seal assembly is disposed within a roller cutter of a roller reamer. A first labyrinth seal assembly of a roller cutter is positioned toward a first pillow block of a cutter cartridge that includes the roller cutter. An optional second labyrinth seal assembly is disposed within the roller cutter and toward second pillow block of the cutter cartridge A bearing shaft of the cutter cartridge extends through an inner channel of the roller cutter. The cutter cartridge is retained in an axial recess of a tool body of the roller reamer via a compound and separate wedging of each of the two pillow blocks into a same axial recess. Each pillow block is rotatably coupled to the bearing shaft at an opposing end of the roller cutter.

Abstract: An integral pressure relief assembly is comprised within a roller assembly of a roller reamer. The integral pressure relief assembly extends through a pair of pillow blocks and a bearing shaft of a retention assembly of the roller assembly. A volume of lubricant is inserted under pressure through a relief valve into an interior channel of the bearing shaft. A spring element in combination with an elastomeric piston provides additional pressure to the pressurized volume of lubricant contained within the integral pressure relief assembly. The lubricant absorbs heat from motion of the bearing shaft and a cutter assembly. As the lubricant increases in pressure, the relief valve releases lubricant from the bearing shaft when a sufficient differential pressure between the contained lubricant and the outside environment is achieved.

Abstract: A rotary drill tool for cutting rock includes a set of journal legs that rotatably mount rotating cone shaped cutters via respective bearing assemblies. A fluid supply passageway extends through the journal legs to provide a cooling and cleaning fluid to the bearings during use. A by-pass passageway extends through a base region of the spindle that mounts each cone cutter and is provided in direct fluid communication with the supply passageway to divert the fluid to a base region of the bearing assembly.

Abstract: A horizontal high-speed testing device for a spiral seal of a cone bit bearing is provided. The device comprises a shaft, a spiral sleeve and a cone. The spiral sleeve is in threaded connection to the cone. Sealing threads are provided on an inner diameter of the spiral sleeve. Both the spiral sleeve and the cone are sheathed on the shaft. By the testing device of the present invention, a spiral seal structure for a cone bit bearing is simulated, and the cone drives the spiral sleeve to rotate; the sand draining performance of the spiral seal can be tested in two ways, i.e., by measuring the time required to drain the sand-containing liquid and by measuring the weight of drained sand, so that the smooth production and application of spiral seal products can be assured.

Abstract: An apparatus for estimating properties of an earth formation includes a carrier connected to a drilling assembly, and a sensor assembly configured to measure at least one return flow parameter of a return fluid at a surface location, the return fluid returning to the surface location from a borehole. The apparatus also includes a processor configured to perform receiving one or more return flow parameter values for a period of time after injection of fluid is stopped, analyzing the one or more return flow parameter values to identify a ballooning event, in response to identifying the ballooning event, estimating at least one of a location and a property of one or more fractures in the formation, and performing one or more aspects of at least one of the drilling operation and a subsequent operation based on at least one of the location and the property of one or more fractures.

Abstract: A down-hole drilling apparatus includes a bearing housing defining a longitudinal axis and upper and lower portions. The upper portion of the bearing housing is configured for connection to a drill string, and at least one annular bearing package disposed within the bearing housing. A drill bit is coupled to the bearing housing and rotatable with respect to the longitudinal axis. The drill bit includes a leading body supporting a plurality of cutters thereon for engaging a subterranean rock formation, a shank portion projecting from the leading body, and a mandrel portion engaging the shank portion and defining an inseparable connection therewith. The mandrel portion extends longitudinally into the bearing housing and through the at least one annular bearing package.

Abstract: A well tool apparatus for damping torsional vibration of a drill string comprises stabilizing members projecting radially outwards from a housing that is, in operation, rotationally integrated in the drill string, to stabilize the drill string by engagement with a borehole wall. The stabilizing members are displaceably mounted on the housing to permit limited angular movement thereof relative to the housing about its rotational axis. The well tool apparatus includes a hydraulic damping mechanism to damp angular displacement of the stabilizing members relative to the housing, thereby damping torsional vibration of the housing and the connected drill string, in use.

Abstract: A down-hole drilling apparatus includes a bearing housing defining a longitudinal axis and upper and lower portions. The upper portion of the bearing housing is configured for connection to a drill string, and at least one annular bearing package disposed within the bearing housing. A drill bit is coupled to the bearing housing and rotatable with respect to the longitudinal axis. The drill bit includes a leading body supporting a plurality of cutters thereon for engaging a subterranean rock formation, a shank portion projecting from the leading body, and a mandrel portion engaging the shank portion and defining an inseparable connection therewith. The mandrel portion extends longitudinally into the bearing housing and through the at least one annular bearing package.

Abstract: A surgical access port and method for achieving articulation is disclosed, the surgical access port including a housing, at least one lumen extending through the housing, and an articulation structure. The housing comprises an access member having a proximal end and a distal end, and defines a longitudinal axis. The lumen in the housing extends from the proximal to the distal end of the access member along the longitudinal axis. The articulation structure comprises a first tubular member and a second tubular member, the second tubular member hingably attached to the first tubular member, and an articulation element slidably attached to the first tubular member.

Abstract: An expandable downhole tool apparatus includes 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. An activation device moves at least one working member between the inward deactivated position and outwardly deployed activated position. 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.

Abstract: A housing, mandrel and bearing assembly positionable in a wellbore includes a torque transmission member adapted to connect to a source of rotational torque (e.g. a downhole motor power output) and a tubular mandrel adapted to connect to a drill bit. A lower tubular housing is adapted to contain a lower bearing and catch sleeve assembly. The catch assembly is adapted to retain the mandrel in the lower housing if the mandrel breaks. An upper tubular housing contains an upper bearing and is adapted to connect to a housing of the downhole motor. A method of assembling the downhole housing, mandrel and bearing assembly is disclosed.

Abstract: A downhole housing, mandrel and bearing assembly 100 includes a flex shaft 20 adapted to connect to a downhole motor power output 309 and a tubular mandrel 30 adapted to connect to a drill bit 370. A lower tubular housing 60 is adapted to contain a lower bearing assembly 90 and catch sleeve assembly 110. The catch assembly 110 is adapted to retain the mandrel 30 in the lower housing if the mandrel breaks. An upper tubular housing 70 contains an upper bearing assembly 80 and is adapted to connect to a housing 302 of the downhole motor 301. A method of assembling the downhole housing, mandrel and bearing assembly 100 is disclosed.

Abstract: The present invention includes compositions and methods of supplying a corrosion inhibitor including placing a corrosion inhibitor attached to a nanostructure carrier, placing the nanostructure carrier containing the corrosion inhibitor at a location and the nanostructure carrier is capable of releasing the corrosion inhibitor.

Abstract: A drill bit of the type used to drill a wellbore in the earth can comprise a bore formed in the drill bit, and a plug sealingly and reciprocably disposed in the bore, whereby the plug prevents fluid communication between sections of the bore in the drill bit. The plug can comprise a spherically-shaped member. The plug can comprise a floating plug sealingly and reciprocably disposed in the bore, whereby pressure in the different sections of the bore on respective opposite sides of the plug is substantially equalized.

Abstract: A drill bit of the type used to drill a wellbore in the earth can comprise a bore formed in the drill bit, and a plug sealingly and reciprocably disposed in the bore, whereby the plug prevents fluid communication between sections of the bore in the drill bit. The plug can comprise a spherically-shaped member. The plug can comprise a floating plug sealingly and reciprocably disposed in the bore, whereby pressure in the different sections of the bore on respective opposite sides of the plug is substantially equalized.

Abstract: The present invention includes compositions and methods of supplying a corrosion inhibitor including placing a corrosion inhibitor attached to a nanostructure carrier, placing the nanostructure carrier containing the corrosion inhibitor at a location and the nanostructure carrier is capable of releasing the corrosion inhibitor.

Abstract: Roller cone drill bits may be provided with pressure relief mechanisms operable to control lubricant pressure within respective lubricant systems. Each lubricant system may be enclosed and isolated from downhole well fluids. Portions of each pressure relief mechanism may be completely surrounded by lubricant to increase downhole life of associated operating mechanisms and to produced more repeatable and more reliable opening and closing of the pressure relief mechanism. The downhole drilling life of bearing surfaces, fluid seals and other supporting structures associated with roller cones mounted on support arms of such roller cone drill bits may be substantially increased. Each pressure relief mechanism may be locked in a closed position to assist with filling the respective lubricant system with lubricant.

Abstract: What is claimed is a downhole lubrication system comprising a drill string component comprising an outer diameter and an inner bore. A reservoir may be disposed intermediate the outer diameter and inner bore. A piston may be disposed at least partially within the reservoir. At least one channel may extend from the reservoir to a bearing surface. As drilling fluid is passed through the inner bore, the piston may be pressurized, urging lubricant toward the bearing surface via the at least one channel.

Abstract: A device including a drill bit is disclosed. The bit preferably comprises lug members, joined by a support member, each lug member includes a through hole, bearings rotatably mounted on the lug members which bearings support cutter members, a sleeve with lubricant mounted upon the support member, a central channel within the sleeve whose lower end can be closed or opened with a reciprocating valve-plate, an annular piston snug-fitting between the sidewalls of sleeve and central channel, which piston has a discharge valve outletting the lubricant through the piston, a spring disposed in the sleeve, rods mounted in the sleeve and inserted through the holes, lubrication channels arranged in the lug members and communicating the lower portion of sleeve with the bearings for lubrication thereof. The rods are coupled to the piston and the valve-plate. Embodiments include shafts supporting the bearings. Some shafts are hollow and have a coolant system.

Abstract: What is claimed is a downhole lubrication system comprising a drill string component comprising an outer diameter and an inner bore. A reservoir may be disposed intermediate the outer diameter and inner bore. A piston may be disposed at least partially within the reservoir. At least one channel may extend from the reservoir to a bearing surface. As drilling fluid is passed through the inner bore, the piston may be pressurized, urging lubricant toward the bearing surface via the at least one channel.

Abstract: An earth bit includes a cutting cone mounted to a lug to form a bearing cavity. A valve is in fluid communication with the bearing cavity and a bit chamber, wherein the valve includes a diaphragm with an aperture. The aperture is repeatably moveable between open and closed conditions in response to a pressure difference between the material in the bearing cavity and bit chamber.

Abstract: What is claimed is a downhole lubrication system comprising a drill string component comprising an outer diameter and an inner bore. A reservoir may be disposed intermediate the outer diameter and inner bore. A piston may be disposed at least partially within the reservoir. At least one channel may extend from the reservoir to a bearing surface. As drilling fluid is passed through the inner bore, the piston may be pressurized, urging lubricant toward the bearing surface via the at least one channel.

Abstract: What is claimed is a downhole lubrication system comprising a drill string component comprising an outer diameter and an inner bore. A reservoir may be disposed intermediate the outer diameter and inner bore. A piston may be disposed at least partially within the reservoir. At least one channel may extend from the reservoir to a bearing surface. As drilling fluid is passed through the inner bore, the piston may be pressurized, urging lubricant toward the bearing surface via the at least one channel.

Abstract: A device including a drill bit is disclosed. The bit preferably comprises lug members, joined by a support member, each lug member includes a through hole, bearings rotatably mounted on the lug members which bearings support cutter members, a sleeve with lubricant mounted upon the support member, a central channel within the sleeve whose lower end can be closed or opened with a reciprocating valve-plate, an annular piston snug-fitting between the sidewalls of sleeve and central channel, which piston has a discharge valve outletting the lubricant through the piston, a spring disposed in the sleeve, rods mounted in the sleeve and inserted through the holes, lubrication channels arranged in the lug members and communicating the lower portion of sleeve with the bearings for lubrication thereof. The rods are coupled to the piston and the valve-plate. Embodiments include shafts supporting the bearings. Some shafts are hollow and have a coolant system.

Abstract: A rotary rock bit includes a lubricant reservoir with a pressure compensation assembly disposed therein. The pressure compensation assembly is adapted to permit selective adjustment of the relief pressure set by the assembly through the selective adjustment of one member in the assembly with respect to another member in the assembly.

Abstract: A drill bit for drilling a wellbore, the drill bit having a body and at least one bearing. A rotary cone is rotatably attached to the bit body at the bearing. A lubricant reservoir is located in an inner portion of the bit body and is in fluid communication with the bearing. A communication port leads from the inner portion of the bit body to the exterior of the bit body. A fiber reinforced elastomeric pressure compensator diaphragm separates lubricant in the lubricant reservoir from the communication port.

Abstract: The invention relates to a roller assembly for a rotary roller reamer. The roller assembly includes a roller pin and a crushing roller. The crushing roller is arranged to be mounted on the roller pin and to rotate thereabout. The roller assembly is connected together so as to form a single cartridge which can be inserted into a pocket of the rotary roller reamer and secured thereto using a single fastener device.

Abstract: The invention relates to a roller assembly for a rotary roller reamer. The roller assembly includes a roller pin and a crushing roller. The crushing roller is arranged to be mounted on the roller pin and to rotate thereabout. The roller assembly is connected together so as to form a single cartridge which can be inserted into a pocket of the rotary roller reamer and secured thereto using a single fastener device.

Abstract: A rotary rock bit includes a lubricant reservoir with a pressure compensation assembly disposed therein. The pressure compensation assembly is adapted to permit selective adjustment of the relief pressure set by the assembly through the selective adjustment of one member in the assembly with respect to another member in the assembly.

Abstract: An earth bit includes a cutting cone mounted to a lug to form a bearing cavity. A valve is in fluid communication with the bearing cavity and a bit chamber, wherein the valve includes a diaphragm with an aperture. The aperture is repeatably moveable between open and closed conditions in response to a pressure difference between the material in the bearing cavity and bit chamber.

Abstract: Lubricating nutating single cone drill bit (10, 100) includes bit shank (12, 112) with axially skewed journal (18, 118) rotatably retaining cutter body (22, 122). Bearings (26, 28, 30, 32; 126, 128, 130, 132) can enable rotation of cutter body (22, 122). Lubricant can be dispensed to a gap between journal (18, 118) and cutter body (22, 122) from lubricant chamber (76; 176, 179) having plunger (80; 180, 183), the gap bounded by first (66, 166) and second (68, 168) radial dynamic seals. Fluid passage (90, 190) extending through bit (10, 100) can communicate with fluid inlet port (88, 188) on proximal end (16, 116) of bit shank (12, 122). Fluid passage (90, 190) can further communicate with first fluid outlet port (98, 198) on distal end (36, 136) of journal (18, 118) and with second fluid outlet port (94, 194) formed on lateral portion of bit shank (12, 112).

Abstract: A lubricating nutating single cone drill bit 10 is disclosed. Bit 10 includes a bit shank 12 with an axially skewed bore 18 rotatably retaining a cutter body 22. A plurality of cutter elements (46, 48) are affixed to the cutter body 22. Bearings (26, 28, 30, 32) enable rotation of the cutter body 22 and lubricant is dispensed to the bearings from a lubricant chamber (76, 76?) by a plunger 80 driven by drilling fluid. A method to drill includes attaching the bit 10 to a drill string, engaging the bit 10 into a formation (WB), pumping a drilling fluid into a plunger 80 in the lubricant chamber 76 to dispense lubricant to the bearings (26, 28, 30, 32). The method can include pumping the drilling fluid through a fluid passage 90 in the bit 10 and out of a low pressure orifice 94 on the cutter body 22.

Abstract: Methods and apparatus for maintaining lubrication of rolling cone cutters mounted on journal pins. Embodiments comprise a rotating cone disposed on a journal pin and forming a journal gap there between. A cylindrical journal sleeve is disposed in the journal gap. The journal sleeve has a longitudinal gap forming opposing end portions, which are continuously contoured. A lubrication port is disposed in the journal pin and in fluid communication with a lubrication supply. The lubrication port has an outlet located in a recess in the journal gap. Each end of the recess comprises a transitioning surface extending between the bottom of the recess and the outer surface of the journal pin to prevent sharp transitions. In certain embodiments, the journal pin may comprise two or more lubrication ports, each located in a recess with transitioning surfaces.

Abstract: An earth boring bit has rotating cones with two lubricant passages to increase bearing capacity and cause lubricant circulation. A lubricant reservoir in the body supplies lubricant to passages between the cone and bearing pin. A pressure compensator equalizes lubricant pressure to the exterior of the bit. A first passage leads from the reservoir to the upper side of the bearing pin. A second passage leads from the reservoir to the bearing pin at a point from 185 degrees to 225 degrees as seen from an inner end of the bearing pin. This point is located in a diverging region 51d of an annular clearance surrounding the bearing pin.

Abstract: A lubricating grease is specific for a rock bit for drilling subterranean formations. The rock bit body includes a plurality of journal pins, each having a bearing surface, with a cutter cone mounted on each journal pin and also including a bearing surface. A grease reservoir provides lubricating grease to such bearing surfaces. The grease composition adjacent the bearing surfaces comprises a lubricating base oil, sufficient thickener and additives in the base oil to form a rock bit grease, and an effective amount of polarized graphite.

Abstract: A roller-cone rock bit in which the compensation reservoir is integrated with a hydrostatically-asymmetric seal, such as a V-seal, which provides pressure relief. This seal not only relieves overpressure during filling, and when the grease thermally expands as the bit first goes downhole, but also compensates transient overpressures during operation.

Abstract: O-ring seals for rock bit bearings comprise a body formed from an elastomeric material having a lubricant additive in at least the dynamic seal surface to reduce the coefficient of friction and stick-slip amplitude at O-ring seal surfaces. The lubricant additive comprises polarized graphite. O-ring seals made from elastomeric compositions comprise in the range of from about 50 to 99 percent by volume elastomeric material, and in the range of from about 1 to 50 percent by volume of the polarized graphite based on the total volume of the composition. Preferably, the polarized graphite is in the range of from 7 to 25 percent by volume. As the O-ring seal experiences wear from adjacent metal surfaces, flakes of polarized graphite are released from the O-ring seal and adhere to the adjacent metal surfaces and form a lubricating film.

Abstract: A rotary cone rock bit, comprises a bit body including a plurality of legs extending therefrom, each of the legs having an outer surface that includes a leading surface and a trailing surface, a roller cone rotatably supported on each of the legs, a bearing system between each cone and the leg on which it is supported, and a lubricant reservoir in fluid communication with the bearing system. The reservoir can be provided with a wear resistant plug, if desired. In the present bit, the reservoir has at least one opening positioned in either the leg's leading surface, trailing surface, center surface, shoulder surface or some combination of these. Alternatively, the reservoir can be formed inside the bit body, preferably by a canister or the like, which can be provided with a venting as desired.

Abstract: The apparatus (10) for delivering grease through the individual string (12) includes a tubular member (14) for holding a supply of grease, a piston (16) sealing slidable through the tubular member (14) and a first valve (18) coupled to a downstream end (20) of the member (14). Valve (18) has a body (22) provided with orifices (24) and a collar (26) slidably mounted over an end of the body (22) and biased to a sealing position in which it seals the orifices (24). Piston (16) is initially located above an upstream end (28) of the tubular member (14). Apparatus (10) is slid through the drill string (12) until collar (26) abuts a stub, typically a core bit retained at the end of the string. Fluid pressure is then applied to apparatus (10) by pumping water or mud down the drill pipe (12). This forces collar (26) to be displaced in covering the orifices (24).

Abstract: A sealing structure for a rock drill bit includes an elastomeric diaphragm for installation in the drill bit so as to separate grease from drilling mud. The diaphragm has an aperture extending through it, and a plug is disposed in the aperture so as to form a mechanical seal with a wall of the aperture. The plug has a channel therethrough which is normally held sealed by a face of the aperture in the diaphragm. If the pressure of the grease exceeds pressure in mud on the other side of the diaphragm by more than a critical value, the diaphragm aperture deforms and allows grease to move through the plug channel and escape. The critical value can be varied by using, with the same diaphragm, plugs having different numbers, sizes and axial positions of plug channels.

Abstract: A lubricant ejector used downhole has a reservoir holding replenishment lubricant, and it includes a driver to eject at least a portion of the lubricant. A flow coupler connected to the ejector channels lubricant to a connected apparatus. One specific ejector includes a hollow rotor of a downhole motor, and a specific flow coupler includes a cross-channel diverter that directs lubricant from the hollow interior of the rotor to a bearing pack and that directs drilling fluid, used to drive the motor and create pressure that moves a piston in the rotor, from outside the rotor to inside a passageway through the bearing pack. A method includes injecting lubricant from a reservoir in the downhole motor into the bearing pack as the downhole motor operates.

Abstract: Canister, sealing method and composition for sealing a borehole. The canister includes a container with slurry inside the container, one or more slurry exits at one end of the container, a pump at the other end of the container, and a piston inside that pushes the slurry though the slurry exit(s), out of the container, and into a borehole. An inflatable packer outside the container provides stabilization in the borehole. A borehole sealing material is made by combining an oxide or hydroxide and a phosphate with water to form a slurry which then sets to form a high strength, minimally porous material which binds well to itself, underground formations, steel and ceramics.

Abstract: A roller-cone rock bit in which the compensation reservoir is integrated with a hydrostatically-asymmetric seal, such as a V-seal, which provides pressure relief. This seal not only relieves overpressure during filling, and when the grease thermally expands as the bit first goes downhole, but also compensates transient overpressures during operation.

Abstract: A bit is provided having at least one leg extending downwardly and inwardly from the bit body. A cutter cone is rotatably mounted on a shaft extending inwardly from the lower portion of each leg. The annular space defined by the base of the shaft and the inner surface at the base of the cone forms a seal gland. An elastomeric o-ring sealingly engages an inner surface of the cone and a first rigid ring which rotates with the o-ring and cone. The o-ring energizes the first rigid ring for sealingly engaging a second rigid ring mounted to the leg of the bit near the base of the shaft. The second rigid ring is secured to and seals against a surface at the base of the shaft and is held stationary relative to the surface. A lubricant passage for lubricating the seal is pressurized by the drilling fluid pressure in the center of the bit body.

Abstract: A pressure compensating assembly for use in roller cone drilling bits of the sealed bearing type. The compensating assembly includes a hollow body arranged to fit into a cavity in the bit connected with the lubrication system of the bit and the hollow body includes a normally open lubricant passageway extending therethrough. A seal encircles the body on one side of the lubricant passageway and is arranged to sealingly engage the bit and an elastomeric, cup-shaped diaphragm is located on the body and has a lip arranged to sealingly engage the bit on the other side of the lubricant passageway. The diaphragm having a protuberance on the side of the diaphragm facing the passageway and sized to enter and close the passageway. The body, seal, and diaphragm being assembled into a unitary cartridge for introduction into the bit as a unit.

Abstract: A rotary cone rock bit, comprises a bit body including a plurality of legs extending therefrom, each of the legs having an outer surface that includes a leading surface and a trailing surface, a roller cone rotatably supported on each of the legs, a bearing system between each cone and the leg on which it is supported, and a lubricant reservoir in fluid communication with the bearing system. The reservoir can be provided with a wear resistant plug, if desired. In the present bit, the reservoir has at least one opening positioned in either the leg's leading surface, trailing surface, center surface, shoulder surface or some combination of these. Alternatively, the reservoir can be formed inside the bit body, preferably by means of a canister, which can be provided with venting means as desired.