Abstract: An elongated structure (100) for the transmission of fluid-based compositions at non-ambient temperatures comprising a first conduit (130) for the transmission of a fluid-based composition, at least one flexible, elongated and inflatable temperature control conduit (110a, 110b) for the transmission of a temperature control fluid, the temperature control conduit (110a, 110b) having a relatively rigid elongated reinforcement member (116a, 116b); and elongated cover (140) holding said temperature control conduit (100a, 110b) in thermal communication with the first conduit (130).

Abstract: A cold plate and method for cooling using the cold plate are disclosed. The cold plate includes a housing having hyperporous, microchannel ceramic foam strips disposed therewithin. A plurality of plugs formed from a high thermal conductivity material are disposed into the ceramic foam strips. Heat is transferred in an extremely efficient manner by leveraging the high thermal conductivity of the plugs to transfer the energy deep into a high internal surface area ceramic foam, which in turn transfers the heat to a coolant via convection. Channels between the foam strips form coolant inlet and outlet plenums, which results in minimal coolant pressure drop through the cold plate. In one example, an exemplary cold plate may provide cooling to one or two printed circuit boards. In another example, a cold plate may be disposed within a heat exchanger housing to provide cooling to a fluid.

Abstract: A heat pipe structure including a pipe body and a working substance is provided. The pipe body has two closed ends opposite to each other, an inner surface, a compressed portion, and an expanded portion. The inner surface and the two closed ends form a cavity. The compressed portion includes a plurality of first grooves formed at the inner surface. Any one of the first grooves includes a first width. The expanded portion includes a plurality of second grooves formed at the inner surface. Any one of the second grooves includes a second width, and the first width is approximately equal to the second width. The working substance is contained in the cavity.

Abstract: A pulsed magnetic field is generated by a device having a magnet to be operated in pulse operation which contains at least one superconductive refrigerant-free winding that is disk-shaped or saddle-shaped. Also included is a refrigerating unit which has at least one cold head. A line system, having a refrigerant circulating in it according to a thermosiphon effect, thermally couples the winding to the cold head. The line system has a plurality of separate pipes lying next to one another. The pipes, open onto a common refrigerant distributor and closed at the other end, are thermally coupled to the surface of the disk-shaped or saddle-shaped winding.

Abstract: A heat sink assembly includes a base, a fin group located at a top of the base, a heat pipe connecting the base with the fin group, a fan mounted on a side of the fin group and a supporting bracket mounted on the base and supporting the fan. The supporting bracket includes a mounting portion secured on the base and a pair of supporting arms extending from the mounting portion and fixed to the fan. Four screws extend through the fan to threadedly engage with the fin group. Lower two of the screws also extend through the supporting arms of the supporting bracket whereby the supporting bracket also connects with the fan.

Abstract: A finned tube includes channels defined between adjacent fins on the tube body outer surface. Wings extend from side walls of the adjacent fins between the fin top and the fin base such that the wings form a barrier which splits the channel into an upper channel and a lower channel. A plurality of holes penetrate the barrier where the wings meet, so liquids and gases can pass into and out of the enclosed area defined by the lower channel. The wings can include alternating upper wings and lower wings, and there can be depressions formed in the fin top.

Abstract: A heated energy system includes an integral ceramic insert heat exchanger having an integral ceramic construction and an outer ceramic wall that is helical in shape. When the heat exchanger is positioned within a surrounding fluid path enclosure, the outer ceramic wall forms, with the enclosure, at least one spiral path for flowing products of energy generation. No more than one insert body has an outer wall that is helical in shape that is present along the first length of the surrounding fluid path enclosure. The outer ceramic wall receives heat energy when the products of energy generation flow through the fluid path. A method for fabricating integral ceramic insert heat exchangers includes using a tool having a silicon carbide channel and a cavity channel, the silicon carbide channel extending at least partially outside the cavity channel in directions defined by a rotational plane of the tool.

Abstract: A heat exchanger including plate fins stacked at respective intervals relative to one another, and heat exchanger tubes penetrating the fins in. The heat exchanger exchanges heat between first and second fluids flowing, respectively, inside and outside the heat exchanger tubes. Each of the fins includes a substantially planar main body and cut-raised portions extending from the main body and disposed at an upstream side of flow of the second fluid. Each of the cut-raised portions corresponds to a respective heat exchanger tube and includes first and second opposed side ends connected to the main body of the fin. The first side end is nearer to the corresponding heat exchanger tube than is the second side end, the first side end is longer than the second side end, and the first side end is disposed at a downstream side of the flow of the second fluid, facing the corresponding heat exchanger tube.

Abstract: Condensate accumulating in the incoming outside air flow passages of a heat exchanger is fed back into the exhaust flow passages of the heat exchanger to provide improved heat transfer in the heat exchanger, and to avoid the necessity for drainage of the condensate from the heat exchanger. The heat exchanger includes a plastic multi-tube panel core and a solid plastic housing, with opposed-flow heat exchange and inlet-outlet extensions from only one side of the core.

Abstract: A process for retorting and extracting sub-surface hydrocarbons. The process comprises drilling an energy delivery well extending from the surface to a location proximate a bottom of the hydrocarbons. The hydrocarbons are heated from the bottom to form a retort, the retort extending along a portion of the energy delivery well. A vapor tube is extended to a location proximate the retort, the vapor tube having an entrance corresponding to the region of the retort along the energy delivery well that is nearest the surface exit.

Abstract: A downhole drilling tool includes a housing defining an axial passageway and a shaft mounted for rotation within the axial passageway such that the housing and shaft form an annular gap. An electrical connector provides a signal to the shaft. The electrical connector includes a first lead assembly coupled to the housing and the shaft, and a second lead assembly coupled to the housing and the shaft. Each lead assembly has an outer ring electrode fixed to the housing and an inner ring electrode fixed to the shaft for rotation therewith such that connector gaps are formed between the outer ring electrodes and the inner ring electrodes. Drilling fluid is pumped through the annular gap to flow through the connector gaps to complete electrical connections between the outer ring electrodes and inner ring electrodes.

Abstract: Methods and apparatus for connecting a tubular to a tubular string are provided. In one embodiment, an apparatus suitable for engaging, compensating, and connecting a tubular includes one or more compensating pistons, an engaging assembly for engaging a tubular, and a connector for connecting the engaging assembly to the one or more compensating pistons while allowing for rotation of the tubular relative to the compensation pistons.

Abstract: The disclosure provides a blowout preventer (BOP) system with a ram having a shear blade with a shear blade profile to shear a tubular member disposed in the BOP. The shear blade profile can include a stress concentrator and centering shaped surface. The stress concentrator and the centering shaped surface can be laterally offset from a centerline of ram travel and on opposite sides of the centerline. An opposing second shear blade can have a mirror image of the shear blade profile with the stress concentrator and centering shaped surface reversed to the orientation of the first shear blade. Further, the ram can include a mandrel with a mandrel profile for the tubular member to deform around during the shearing process and to reduce an overall lateral width of the sheared tubular member in the BOP through-bore to allow retrieval of the deformed sheared tubular member from the BOP.

Abstract: An apparatus for reverse circulation cementing of surface casing in subterranean formations and associated methods are provided. One example of a method may involve a method of reverse circulation cementing a surface casing in a well bore with a conductor casing positioned therein comprising: providing a tool comprising at least one isolation device coupled to the surface casing; positioning the isolation device in the well bore to isolate an annulus between the surface casing and the conductor casing; flowing cement through a port in the conductor casing in a reverse circulation direction; and allowing the cement to set therein.

Abstract: A method for the controlled delivery of a fracturing fluid to a well bore comprises formulating an aqueous base fluid such that it meets or exhibits desired physical and chemical characteristics for an optimal fracturing fluid. The formulation of the aqueous base fluid max involve commingling one or more sources of waste water with a source of fresh water followed by controlled injection of one or more additives. This process is substantially completed prior to delivering the aqueous base fluid to the well site. This allows the delivery of an optimal volume of the aqueous base fluid with homogeneously blended additives to the well bore.

Abstract: An injection backflow method for measuring fracture surface area adjacent to a wellbore measures an initial temperature profile along the length of a wellbore. A tracer composition is injected into the wellbore at an initial concentration. The tracer composition includes a reactive tracer and a secondary tracer that is less reactive than the reactive tracer. The tracer composition diffuses within subterranean reservoir for a time. A secondary tracer concentration and a reactive tracer concentration are measured as a function of time. A reservoir fracture surface area is calculated using a reservoir fluid flow model.

Abstract: A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore at a flow rate, determining velocities of the MEMS sensors along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the velocities of the MEMS sensors and the fluid flow rate. A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore, determining positions of the MEMS sensors relative to one or more known positions along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the determined positions of the MEMS sensors.

Abstract: An apparatus for use in deployment of downhole tools is disclosed. Preferably, the apparatus includes at least an in-ground well casing, a housing providing a hermetically sealed electronics compartment, a tool attachment portion, and a first flow through core. The housing is preferably configured for sliding communication with the well casing. The hermetically sealed electronics compartment secures a processor and a location sensing system, which communicates with the processor while interacting exclusively with features of the well casing to determine the location of the housing within the well casing. A preferred embodiment further includes a well plug affixed to the tool attachment portion, the well plug includes a second flow through core capped with a core plug with a core plug release mechanism, which upon activation provides separation between the second flow through core and the core plug, allowing material to flow through said first and second flow through cores.

Abstract: A downhole tool for use in a well may comprise a vessel having a piston or a valve disposed therein and defining first and second volumes wherein the first volume is configured to receive formation fluid from an inlet port, and an actuator configured to extract formation fluid, the actuator being fluidly isolated from a fluid flow path extending between the inlet port and the first volume. The downhole tool may also comprise a flow-line configured to deliver formation fluid to the vessel, and an actuator configured to register an end of the flow-line with the inlet of the vessel.

Abstract: A elongated plunger assembly for pressurized, conduit-enclosed travel utilized in recovery of hydrocarbon deposits in a ground penetrating oil or gas well. The plunger comprises an elongated mandrel, a plurality of radially movable curvilinear wear pads circumferentially disposed adjacent each end of the elongated mandrel, a pad-edge retaining housing extending on at least one end of the elongated mandrel to enclosably retain the longitudinally distal end of a circumferential array of wear pads onto the mandrel, and a centrally disposed wear pad securement ring arrangement to permit release of a worn wear pad, replacement of the worn wear pad at an inner longitudinal edge thereof, thus to permit simple field-accessable removal and replacement of any particular “conduit-worn” “wear” pad from the mandrel of the plunger.

Abstract: One apparatus for releasing a chemical in a well bore includes a casing collar configured to couple to a casing string. A chemical container is disposed within the casing collar, and the casing collar is configured to release the chemical from the chemical reservoir.

Abstract: The present disclosure is directed to a system and method for managing cement in a subterranean zone. In some implementations, a method of cementing in a subterranean formation includes positioning a cement slurry including a plurality of activation devices in a wellbore. The activation devices configured to release an activator that increases a setting rate of the cement slurry. A signal is transmitted to at least a portion of the cement slurry to activate the activation devices. The activation device releases the activator in response to at least the signal.

Abstract: A method of treating a subterranean formation includes pumping into a cased, perforated wellbore that intersects the formation an invert emulsion kill fluid, the invert emulsion kill fluid comprising: an oleaginous continuous phase; a non-oleaginous discontinuous phase; an emulsifier; at least one degradable material; and at least one bridging material; contacting the formation with the kill fluid; and allowing the degradable material to at least partially degrade.

Abstract: The present invention includes methods relating to the setting of fluids or slurries in a wellbore. In one embodiment, a method of isolating a portion a wellbore by preparing a sealant composition comprising a fluid component and a polymeric additive component, placing the sealant composition into a wellbore and subjecting the sealant composition to ionizing radiation. The ionizing radiation can cause bonding between polymeric additive components and create a polymer matrix within the sealant composition that increases the mechanical strength of the sealant composition.

Abstract: Methods and compositions are provided that relate to cementing operations. Methods and compositions that include a latex strength enhancer for enhancing the compressive strength of slag compositions.

Abstract: A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300° C.

Abstract: A gas-lift valve comprising an elongated vertically orientated tubular body with inlet ports positioned for communication with the inlet ports of a gas-lift valve mandrel, a valve seat and valve port at the upper end of the valve body, a movable gas charged dome positioned within the body below the valve seat, a valve ball assembly attached to the dome, and a collapsible bellows positioned to move the dome and manipulate the valve ball assembly downward onto and off of the valve seat in response to pressure from said inlet ports of the valve body and pressure on the seat and thereby allow injection gas to flow upward through the valve port to exit at the upper end of the valve body. A tubular latch is provided with a removable plug to provide for pressure testing and completion of the well with only one wireline trip.

Abstract: A remotely operated submersible vehicle (ROV) is used to carry a bridge plug down to a sub sea well. The ROV is operated from a surface vessel or platform and is outfitted with a submersible hydraulic pump and a manipulator arm. Additionally, the ROV is provided with a carrying rack which can support a well closure assembly made up of an inflatable bridge plug and an affixed hydraulic running tool. The bridge plug and running tool are placed into the carrying rack and operably interconnected with the hydraulic pump so that the plug element can be selectively inflated by the pump.

Abstract: An improved motion compensator device that includes a compensated framework for various types of well intervention operations where a stable work area is required that is stationary to the sea bed and equipment in the annulus. The device is intended for use on offshore drilling vessels that are primarily either moored or dynamically positioned and therefore subject to the motions created by the sea. The device is designed to compensate for the vertical motion of the rig by means of two steel frame assemblies, pneumatic compensating cylinders, and a load and motion transfer apparatus.

Abstract: Dual gradient drilling may be performed by anchoring drilling tubulars from a drilling ship on the seabed. The drilling tubulars may include an inline pump for pumping mud through another set of tubulars that actually drill the well. Then dual gradient drilling may be instituted by controlling the pressure by controlling the operation of the pump.

Abstract: An autonomous junk collecting sleeve for a riser is provided. The sleeve is constructed and arranged to be independently lowered and seated above a subsea tree section and, subsequently, raised and removed independent of the work string. The autonomous junk collecting sleeve includes a first cylindrical structure, a second cylindrical structure concentric to the first cylindrical structure and which are joined together in spatial relation at a bottom end to form an interior J-channel basket. The J-channel basket is operable to collect debris traveling up through the bottom end and over of the second cylindrical structure for deposit therein.

Abstract: A system for operating downhole equipment in a well includes a drive shaft extending from a surface of the well to a downhole location. A motor is positioned at the surface and is operably connected to the drive shaft to selectively rotate the drive shaft. A lift system is positioned at the surface and is operably connected to the drive shaft to axially lift and lower the drive shaft.

Abstract: A downhole tool has housing components that are relatively movable. One of the components is supported downhole while a control line provides fluid pressure to move the other housing component relative to the supported component to put the tool in a first position. Loss of control line pressure allows the weight of tubulars bearing on the upper housing or rods to move it to put the tool in another position. The tubing weight overcomes the hydrostatic pressure in the control line even when there is no applied pressure in the control line to cause relative housing or rods movement to operate a tool. In that sense the tool can be fail safe to shut off flow, for example, on loss of control line pressure while reducing or elimination the need for a large return spring to offset hydrostatic pressure.

Abstract: A method and apparatus for expanding a tubular below a restriction in a wellbore. An expandable tubular may comprise a first end having a first wall thickness, a second end having a second wall thickness, and a middle section disposed between the first and second ends and having a third wall thickness that is less than the first and second wall thicknesses. The first and second ends may include one or more grooves disposed along a length of the ends. A method for expanding a tubular below a restriction in a wellbore may comprise running the tubular past the restriction, wherein the tubular comprises a first end and a second end, each end having a wall thickness greater than a wall thickness of a middle section disposed between the ends. The method may include expanding the tubular, wherein the first and second ends of the expanded tubular have outer diameters greater than the outer diameter of the middle section.

Abstract: A pilot valve assembly for regulating the output of a first pressure source relative to a second pressure source, a fluid system equipped with the valve assembly, and a method of operating the valve assembly. The valve assembly includes a valve body with inlet and outlet ports and first and second sensing ports. The first and second sensing ports are adapted to sense, respectively, the fluid pressures of the first and second pressure sources. The inlet port is adapted for fluidically connecting to the first pressure source. The valve assembly defines a flow path between the inlet and outlet ports, and has components for allowing fluid flow from the inlet port, through the flow path, and to the outlet port only if the fluid pressure of the first pressure source exceeds the fluid pressure of the second pressure source by a differential by the flow-allowing components.

Abstract: An upright fire protection sprinkler having an input orifice at an input end of the sprinkler for receiving fluid and an output orifice at an output end of the sprinkler for outputting fluid. The sprinkler has a connection portion at the input end of the sprinkler and a body extending between the connection portion and the output end. A pair of frame arms extends from the output end and meets at a hub positioned in axial alignment with the output orifice. A deflector is positioned on the hub and is configured to direct fluid output from the output orifice substantially in a direction back toward the output end.

Abstract: To dissipate hydraulic shock created by the bouncing of an implement mounted on a wheeled vehicle, such as a towed tillage implement or the bucket of a vehicle, such as a wheel loader, an electronic control valve, which supplies hydraulic fluid to the hydraulic actuator that raises and lowers the implement, is actively controlled by an electronic controller. As the vehicle with an implement is transported at higher speeds, the implement tends to bounce creating pressure spikes in the hydraulic system that raises and lowers the implement. The pressure spikes are dissipated by actively generating random or cancelling hydraulic pulses in the hydraulic system.

Abstract: An implement that conditions the ground surface as it is moved there over aerating the soil and distributing fertilizer and/or seeds thereon. The implement has a pair of aerator rollers mounted on a frame that can be towed by a tractor or constructed so as to be self-propelled if so desired. The aerator rollers project below the frame for rolling engagement with the ground and are located one behind the other in tandem relation relative to the direction of travel of the implement during use thereof. Each aerator roller has a plurality of formations defining teeth that penetrate the ground surface. The formations on each aerator roller are spaced apart from one another circumferentially around and longitudinally along the roller associated therewith and such formations on one aerator roller are offset from those on the other roller permitting overlap of the same. The aerator rollers are interconnected in drive and driven relation to rotate in a predetermined ratio.

Abstract: A tiller can include a frame supported by at least one wheel. An upright assembly can extend from the frame. A drive mechanism can be supported by the frame and include a motor having an output member. A tilling implement can have a drive shaft that is driven by the output member. The tilling implement can comprise at least one tine plate. A slider assembly can communicate with the wheel and be movably coupled along the upright assembly. The slider assembly can be configured to securably locate in at least a first position wherein the wheel is located at a first elevation relative to the frame and a second position wherein the wheel is located at a second elevation relative to the frame. The first and second elevations can be distinct.

Abstract: A device for impacting a fastener in one embodiment includes a drive mechanism configured to impact a fastener, a lever arm pivotable between a first position and a second position, and a motor including a plurality of permanent magnets mounted on a rotatable housing, the motor mounted on the lever arm such that when the lever arm is in the first position, the rotatable motor housing is isolated from the drive mechanism and when the lever arm is in the second position, the rotatable motor housing is positioned to transfer rotational energy to the drive mechanism.

Abstract: An ergonomically enhanced electric power tool is disclosed that incorporates a new type of user grip and control system. This grip and control system is housed in a substantially rigid control-housing sheath, which provides enhanced leverage and control over the drilling process while reducing stress on the user's hand, wrist, and arm. The tool motor is disposed substantially in parallel with the user's wrist, but on a different plane, and eliminates the traditional “pistol” type of power-tool grip. The control-housing sheath contains a grip-controller assembly that allows the user to control most major drill operations within the gauntlet-like control-housing sheath. The inventive concepts described can be applied to myriad hand-held power tools, and a detailed example for a power drill is provided.

Abstract: A powered hammer includes a body in which is disposed a motor and a hammer mechanism driven by the motor when the motor is activated. A tool holder is coupled to a front portion of the body and which is capable of holding a cutting tool. The hammer mechanism, when driven by the motor, is capable of imparting impacts to a cutting tool, when held by the tool holder. A handle is moveably coupled to a rear portion of the body for movement toward and away from the body along a tool axis of the tool holder. The handle includes a grip portion and first and second end connection sections coupled to opposite end portions of the grip portion. The first and second end connection sections are slideably mounted on first and second arms that project rearward from the body. A movement control mechanism is mounted inside the handle and coupled to the first and second arms and the handle.

Abstract: A system and method for downhole measurement for use with drill strings to reduce the borehole gap with respect to sensors carried by the drill string. In one embodiment, the sensors are mounted on a surface of the directional drilling hinged pad that comes in contact with the borehole wall. The hinged pad is pressed against the borehole wall as contact is made with the wall, thereby keeping the sensors at a minimum gap with respect to the wall. In another embodiment, the hinged pad is not used for directional drilling. Therefore the hinged pad is extended outward to the wall with the minimum necessary amount of force. Activation of the hinged pad can be initiated, for example, by flow of mud in the annulus of the string or through a user-provided command. The sensors can include resistivity, density, neutron, electromagnetic, acoustic, seismic, and NMR measurement sensors.

Abstract: A drill bit made according to one embodiment includes a bit body and at least one preloaded sensor in the bit body. In one aspect, the sensor may include a sensor element on a sensor body having a first end and a second end and wherein the sensor is preloaded after placing the sensor body in the bit body. In another aspect, the sensor may be preloaded outside the bit body and then placed in the bit body in a manner that enables the sensor to retain the preloading.

Abstract: Disclosed is an apparatus for vibrating a downhole drill string operable to have a drilling fluid pumped therethrough. The apparatus comprises a tubular body securable to the drill string and having a central bore therethrough, a valve in the tubular body for venting the drilling fluid out of the drill string and a valve actuator for cyclically opening and closing the valve. The method comprises pumping a drilling fluid down the drill string and cyclically venting the drilling fluid through the valve so as to cyclically reduce the pressure of the drilling fluid in the drill string. The valve may comprise a tubular body port and a corresponding rotor port selectably alignable with the tubular body port as the rotor rotates within the central bore. The valve actuator may comprise at least one vane on the rotor for rotating the rotor as the drilling fluid flows therepast.

Abstract: A system and method for excavating a formation according to which at least one vessel that is selectively pressurized from a first pressure to second pressure to inject a suspension of liquid and a plurality of impactors into a formation to remove at least a portion of the formation.

Abstract: In an aspect, an apparatus may include a chamber configured to receive a core at a receiving end of the chamber and a cutting device configured to cut the core at a location distal from the receiving end of the core chamber. In aspects, a method may include drilling into the formation to retrieve a core, receiving the core into a chamber at an open end of a chamber, and cutting the core uphole of the open end of the chamber so as to continue to receive the core into the chamber as the drilling continues.

Abstract: A force balanced asymmetric drilling reamer comprising a plurality of blades, each blade having at least one cutter section and a gage section. The cutter section is designed to have a plurality of cutting devices for cutting through swelling formations and cutting free sloughing formations. The gage section has a full bore diameter with gage elements flushly coupled to gage section's outer surface. The blades may be curve/concave shaped or boomerang/chevron shaped, which thereby agitate the cutting beds. At least a portion of the drilling reamer's diameter is incrementally force balanced, starting from the outermost diameter, so that the net radial force is less than 10% of weight on bit with respect to the center of rotation. This balancing allows a greater cutter longevity and provides for a better wellbore condition. Optionally, at least a portion of the drilling reamer's surface may be treated by nitriding for repelling the cuttings.

Abstract: Embodiments of the invention relate to superabrasive compacts including multiple superabrasive cutting portions and methods of fabricating such superabrasive compacts. In an embodiment, a superabrasive compact comprises a cemented carbide substrate including a first interfacial surface and a second interfacial surface longitudinally spaced from the first interfacial surface. A first superabrasive cutting portion may be bonded to the first interfacial surface of the cemented carbide substrate. The first superabrasive cutting portion includes a first working surface. A second superabrasive cutting portion may be bonded to the second interfacial surface of the cemented carbide substrate and spaced from the first superabrasive cutting portion. The second superabrasive cutting portion includes a second working surface that generally opposes the first working surface of the first superabrasive cutting portion.

Abstract: Theme To provide a small-sized crawler device that can stably ride over bumps or steps or stairs. Means to Solve The crawler device includes a device body (1) having main crawlers (20) on its left and right and auxiliary crawlers (30) provided as auxiliary members at one end portion of the device body. Before the crawler device ascends a step or stairs with the auxiliary crawler (30) positioned backward, the controller (65) brings the auxiliary crawler (30) into a preparatory state in which the auxiliary crawler (30) is freely rotatable with respect to the main crawler (20) or the auxiliary crawler (30) is maintained in a position above a line extending longitudinally from the main crawler by a predetermined angle.