Abstract: A roller guide wheel contains a single set of spherical bearings and is constructed with a precision outer race machined into the guide wheel interior and an inner race formed by the surfaces of two conically-tapered set screws that affix the roller guide wheel within a housing made part of a stage slider. The roller guide wheel, which contacts a rail on one side of the stage body and exhibits a non-nutating axis of rotation, serves as way for the translating slider. The way on the opposing side of the slider is a set of v-groove contacts that make sliding contact with a rail on the corresponding side of the stage body. A flexure is machined into the slider permitting preload of the slider contacts points with the rails. The stage geometry permits a large slider through-hole and the use of alternative way mechanisms with the roller guide wheel.

Abstract: Surface treatment of a tubular surface defining an axis extending from a first surface end to a second surface end includes partially surrounding the tubular surface, at a first position, with a first set of treating units, with the treating units arranged in a first arcuate array. Furthermore, each treating unit is configured to include a plurality of first applicator heads. In some examples, a position of each of the plurality of first applicator heads is determined relative to the tubular surface. The first set of treating units is moved from the first position towards a second position. In one non-limiting example, each of the plurality of first applicator heads is independently controlled to selectively apply a first treatment as the first set of treating units moves from the first position towards the second position.

Abstract: An object is to provide a mounting structure of a bearing member which enables size and weight reduction of entire apparatus and also contributes to cost reduction thereof. The mounting structure of a bearing member includes: a bearing member for supporting a rotary shaft; a case member to which the bearing member is mounted; and a mounting plate for clamping the bearing member in an axial direction of the rotary shaft in conjunction with the case member, wherein the mounting plate includes a mounting portion of a counter member which is mounted to the case member and clamps the case member in the axial direction in conjunction with the counter member.

Abstract: A paint can-clamping device applicable to a double-gyroscopic mixer is disclosed, including a lower supporting plate, left and right guide rails, an upper pressing plate and a locking mechanism. The locking mechanism includes an upper pressing plate-fixing frame, a locking piece and a locking piece spring. The upper pressing plate is connected to the upper pressing plate-fixing frame via a guide pole. A cam structure having a cam handle is mounted in the upper pressing plate-fixing frame, and is cooperated, via a cam pressing mechanism for pressing the locking piece downwardly, with the locking piece such that the locking piece moves away from the V-shaped groove of the guide rail to be in unlocking state, thereby achieving a linear movement of the upper pressing plate along the guide rails.

Abstract: Disclosed is a control system and method for controlling a superturbocharged engine system in various operation modes. Throttle control mode may idle the superturbocharger during low and medium engine loads, so that boost is not created in the intake manifold. During high engine load conditions (open throttle), boosting occurs in response to the driver, operator, or control system requesting increased engine loads. For transient control mode, the control system may respond to transient conditions in response to engine speed and load so that the engine does not bog down or overcome vehicle traction limits. The control system may also predict future operating points.

Abstract: A harmonic drive according to the present invention comprises a plurality of internal gears; a band type of flexible gear provided with teeth engaged with each of the internal gears on its outer circumferential surface, the flexible gear having a pitch circumference length shorter than that of said internal gears; and a wave generating part disposed on an inner side of said flexible gear, the wave generating part generating a plurality of harmonic motions by deforming said flexible gear as the wave generating part rotates. Further, said flexible gear is formed integrally to engage with said plurality of internal gears so that the plurality of harmonic motions are overlapped, and one or more of said plurality of internal gears and said flexible gear are formed of profile shifted gears.

Abstract: A vibration exciter for a ground compactor comprises an exciter shaft having at least one exciter weight disposed thereon and having at least one turnover weight which is disposed so that it can rotate relative to this exciter shaft. A ground compactor having such a vibration exciter is also disclosed.

Abstract: An orbital motion attachment for a die grinder includes a flexible collar mounted at a first end to a locating support ring and the locating support ring being removably secured to the die grinder. A collet has an offset bearing shaft extending from a first end. The collet is connected at a second end to an output shaft of the die grinder and the offset bearing shaft is connected at a second end to an applicator tip. An indexing ring is affixed to a second end of the flexible collar to secure the applicator tip to the offset bearing shaft.

Abstract: A fixed scroll is provided with a pin shaft portion which is formed in a cylindrical shape. Formed in a movable scroll is a slide groove which extends in the radial direction of the movable scroll. The pin shaft portion of the fixed scroll is engaged into the slide groove of the movable scroll. During orbital movement of the movable scroll, the pin shaft portion slidingly contacts a side surface of the slide groove, whereby rotation of the movable scroll is restricted.

Abstract: The invention provides an eccentric thrust bearing assembly capable of bearing axial loads in opposite directions. A first aspect of the invention relates to a thrust bearing assembly a1 wherein a first radially outside member and a second radially inside member oppose each other at first positions a21 separately located and clamp therebetween a rolling element a8 disposed at each of the first positions a21, whereas a second radially outside member and a first radially inside member oppose each other at second positions a22 of a different phase from that of the first positions a21 and clamp therebetween a rolling element a8 disposed at each of the second positions a22. In this bearing assembly a1, respective certain portions of the rolling elements are present on the same plane.

Abstract: An apparatus for moving a mass, the apparatus having an arcuate track, a clamping member attached to a section of the arcuate track, an arm assembly pivotably connected to the clamping member, and a counterweight connected to the arm assembly. A projectile for use in a mass accelerator having an arcuate track, the projectile having a core and at least one of a low-friction layer, a propellant layer, and a polycarbonate layer.

Abstract: A fixed scroll (60) is provided with a pin shaft portion (70) which is formed in a cylindrical shape. Formed in a movable scroll (50) is a slide groove (80) which extends in the radial direction of the movable scroll (50). The pin shaft portion (70) of the fixed scroll (60) is engaged into the slide groove (80) of the movable scroll (50). During orbital movement of the movable scroll (50), the pin shaft portion (70) slidingly contacts a side surface of the slide groove (80), whereby rotation of the movable scroll (50) is restricted.

Abstract: An iron-base sintered part having high density and totally enhanced strength, toughness and abrasion resistance, a manufacturing method of the iron-base sintered part, and an actuator are disclosed. The iron-base sintered part is formed by an iron-nickel-molybdenum-carbon-based sintered alloy, has density of 7.25 g/cm3 or more, and has a carburization quenched structure. A method for manufacturing the iron-base sintered part includes a molding process of charging a raw mixture powder of an iron-nickel-molybdenum-based metal powder and a carbon-based powder into a cavity of a molding die and compressing the raw powder in the cavity to form a consolidation body, a sintering process of sintering the consolidation body at a sintering temperature to form a sintered alloy, and a carburization quenching process of heating the sintered alloy in a carburization atmosphere and quenching the heated alloy.

Abstract: A portable power tool having a turbine unit (10a, 10b) is proposed, which is intended to be driven by a suction air flow (12a; 12b), and having a gearing unit (14a; 14b; 14c) via which the turbine unit (10a, 10b) is coupled to an output unit (16a; 16b; 16c).

Abstract: The invention relates to an oscillation generating device for use in a soil compacter with a tipping moment compensation device. A second unbalance shaft pair with oppositely rotating unbalance shafts is arranged adjacent to a first unbalance shaft pair as a tipping moment compensation device. Diagonally opposite unbalance shafts rotate in the same direction. In this way, centrifugal forces and torques on the two unbalance shaft pairs reciprocally cancel each other out so that no tipping moment occurs parallel to the axes of rotation of the unbalances.

Abstract: A drive crank shaft and a load shaft with an eccentrically placed center shaft coupler form a mechanical torque transferring structure. Two convoluted rubber seals mounted on a center shaft coupler, a drive shaft support an a load shaft support enclose the working fluid to form double hermetic sealing. The rubber seals exert enough force against twisting to hold the center shaft coupler and prevent the center shaft coupler from rotating around its center. Two balance weights are mounted on both crank shafts symmetrically to eliminate vibration due to eccentric configuration. An enclosed housing prevents fluid from leaking into the environment. A sensor is used to detect the leakage and control the operation. This rotary shaft sealing device provides dynamically hermetic sealing by eliminating a leaking path for the pressurized working fluid.

Abstract: An adjusting device (11) is for regulating the eccentric moment of an eccentric shaft (2) of a roller drum (1) through the influence of an axially directed force transmitted by a force transmission mechanism (12) to a turning device (5), in order to cause a rotation of the eccentric shaft (2). The force transmission mechanism (12) is connected to the adjusting device (11). The adjusting device (11) incorporates a driving device (20), a transmission (19), a tube sleeve (17) and a guide screw (14) which is rotatably arranged in a threaded bore (16) in a journalling shaft (15) for the roller drum (1). The driving device (20) is connected to the tube sleeve (17) via a transmission (19) for transmitting a rotary movement to the tube sleeve (17).

Abstract: An eccentric shaft assembly for a vibratory roller utilizes a cylindrical tubular shaft that considerably reduces the weight of the assembly, decreases substantially oscillatory shaft deflection during rotation and thereby improves bearing and seal life. The eccentric weights are mounted on the interior of the tubular shaft, thereby simplifying manufacture and providing a smoother operation.

Abstract: A spiral mass launcher for moving a mass including a spindle support assembly; connected to a swing-arm pair module. The spindle support assembly rotates on a motor shaft, allowing the swing-arm pair module to swing on a parallel bearing shaft. A spiral track passes through a radial opening in the bearing shaft. Thus, the swinging motion of the swing-arm pair modules allows the spiral track to move in a gyrating motion. The spiral track has a first end and a second end, the first end adapted to receive a mass or projectile and a second end adapted to launch the mass. A mass can be fed into the spiral mass launcher by either a feed mechanism that feeds the mass into the first end of the spiral. Such feed mechanisms include a feed mechanism that linearly oscillates and picks up the mass at a first amplitude of oscillation and feeds the mass into the first end of the spiral track at a second amplitude of oscillation; or a feed mechanism that includes a continuous tube and “crank arm” feed.

Abstract: A scroll thrust bearing having both-end conical rollers are rolling elements, being low in cost, high in precision, large in load capacity, and excellent in durability. A plurality of both-end conical rollers are held rotatably between a pair of bearing plates, and the relation of the scroll swirl radius (R) of both-end conical roller and the dimension (H) between opposite tracks of the both bearing plates is set in a range of 1<H/R<5. As compared with the preset scroll swirl radius (R) of both-end conical roller, the section curvature in the contact portion with the tracks of the both bearing plates of the conical surfaces of the both-end conical roller is kept as small as possible in a practical range, so that the surface pressure acting on the conical surfaces of the both-end conical roller is kept as small as possible.

Abstract: A torque transmission device for providing steplessly variable torque conversion. The torque transmission device has a set of unidirectionally-rotatable, slotted levers radiating from a first axis, capable of engaging a torque output ring which is also rotatable on the first axis. An abaxial ring, which has studs that operate in the slots of the levers, is rotatable on a parallel second axis which can orbit the first axis. Torque input induces the second axis to orbit the first, and the force of orbital motion bears, through the abaxial ring, on at least one lever in a direction opposite its rotatable direction, holding it fixed, and also bears on at least one other lever in a direction that coincides with its rotatable direction, causing it to rotate. The fastest-rotating lever engages and drives the torque output ring. Varying the distance between the first and second axes varies the torque conversion ratio.

Abstract: A vibratory mechanism which is composed of vibratory shafts, which are stored within a roll and are arranged symmetrically across a rotation axis of the roll, a fixed eccentric weight fixed to respective vibratory shafts, a rotatable eccentric weight rotatably attached to respective vibratory shafts, a rotation controller controlling a range of movement of the rotatable eccentric weight, and an eccentric moment controller which changes an eccentric moment around the vibratory shaft depending on the rotation direction of the vibratory shafts, whereby the vibration state of the roll is switchable between standard vibration and horizontal vibration.

Abstract: The invention relates to an internal combustion vibrator for compacting concrete, comprising a vibrator housing in which a rotational unbalance mass, an electric motor powering said unbalance mass and part of a power line connected to the electric motor for supplying power to said electric motor are integrated. The internal vibrator also comprises an interrupter interconnected in the power line for interrupting power supply of the electric motor. Due to the fact that the interrupter is configured in an electrically controllable manner, power supply of the electric motor can be precisely controlled by a plurality of signal transmitters.

Abstract: The conversion of vibration induced rotation into translational motion is effected by engaging two threaded bodies with a gap between them and vibrating one of the bodies to induce rolling contact rotation between the threads of the bodies relative to each other and generating a net translational motion of the other body along the axis of the threads of the translating body.

Abstract: A device and method to convert ordinary rotary motion of input frequency &OHgr; into a composite motion with the same primary frequency &OHgr; plus an eccentric motion at a higher frequency &ohgr; enables a low speed rotary input to drive a higher-speed eccentric motion. A preferred embodiment enables an existing rotary motion machine to be easily adapted to provide compound rotary and eccentric motion. Optional attachments are used to collect waste products generated by rotary motion machine.

Abstract: A spiral mass launcher is disclosed. The spiral mass launcher includes provisions that permit greater packing density and permit better support of a track. Some of these provisions include the use of specially designed angled swing arms. The spiral mass launcher also includes provisions to assist the spiral in achieving faster gyration speeds. Some of these provisions include improved arm designs and vacuum enclosures. A feed mechanism for a spiral mass launcher is also disclosed.

Abstract: A simple device producing both action effect and electronic effect includes a housing, an elastic driving mechanism and an electronic control circuit with a vibration sensor. The elastic driving mechanism has an elastic member, a transmitting shaft, a power input device, an eccentric action member. The electronic cir-control circuit has a circuit board, the vibration sensor, a battery and a function device. The elastic member stores and releases energy, and a changed energy is produced in the storing and releasing process. The eccentric member is connected to the output shaft of the elastic driving mechanism and rotated by the changed energy to produce vibration or jumping phenomenon. Then the vibration sensor senses the vibration phenomenon and triggers a signal of changing its own condition and starts the electronic circuit to produce function to let the function device perform preset action or function.

Abstract: The velocity of a mass is monotonically increased from an initial non-zero value at the time it enters a spiral track. A drive gyrates the track about an axis so the mass makes each turn around the track in about the same period of time. The drive includes plural rotary drive shafts eccentrically and fixedly connected to the track at several points. The drive shafts and track are arranged so points on a first side of a particular spiral turn where the mass is located are driven toward the axis and points on a second side of the particular spiral turn remote from where the mass is located are driven away from the axis.

Abstract: A device and method to convert ordinary rotary motion of input frequency .OMEGA. into a composite motion with the same primary frequency .OMEGA. plus an eccentric motion at a higher frequency .omega. enables a low speed rotary input to drive a higher-speed eccentric motion. A preferred embodiment enables an existing rotary motion machine to be easily adapted to provide compound rotary and eccentric motion.

Abstract: A mass located in a track defined by a closed, continuous path is gradually and smoothly accelerated or decelerated by controlling movement of the track so a portion of the track where the mass is sensed to be located is moved inwardly (for acceleration) or outwardly (for deceleration) along a local radius of curvature of the track.

Abstract: A hand grinder, comprising a housing, a motor arranged in the housing, a tool holder with a grinding tool received in the tool holder, a work shaft driven by the motor, two rotary bearings which support the work shaft, a compensating unit arranged on the work shaft for joint rotation therewith between the rotary bearings and provided for compensation of an imbalance produced by the tool holder with the grinding tool during rotation of the work shaft, the compensating unit including different imbalance masses which are offset from one another in an axial direction of the work shaft and are arranged on the work shaft diametrically opposite to one another.

Abstract: A roller bearing by far less costly and highly accurate compared with conventional products and having double-cone rollers as rolling elements. A plural number of track pockets are provided facing a pair of parallel bearing plates, double-cone rollers are swivelably and rollably held in the opposing pair of track pockets respectively, both the bearing plates are connected and held in a state relatively swivelable by a connecting mechanism.

Abstract: An infinitely variable rotary drive transmission system which provides a true infinitely variable speed range that begins with zero output and accelerates smoothly and steplessly into the over-drive range, provides limitless horsepower capacity and does not require a clutch mechanism to change speeds. The infinitely variable rotary drive transmission system comprises an input shaft, hub assembly, a plurality of identical differential gear assemblies and a plurality of cam rod assemblies operatively coupled to vary the rotational output velocity of an output shaft.

Abstract: The inner circumference 4a2 of the bearing ring 4a is square-shaped, and the outer circumference 4a3 thereof is circular. The shoulder 1a1 of the attaching portion 1a of the scroll member 1 is formed to be square-shaped, corresponding to the inner circumference 4a2 of the bearing ring 4a. When attaching the bearing ring 4a to the attaching portion 1a, the square-shaped inner circumference 4a2 of the bearing ring 4a is fitted to the square-shaped shoulder 1a1 of the attaching portion 1a. Thus, by fitting the inner circumference 4a2 of the bearing ring 4a to the shoulder 1a1 of the attaching portion 1a, the bearing ring 4a is prevented from rotating with respect to the swivel scroll member 1.

Abstract: A mass located in a track defined by a closed, continuous path is gradually and smoothly accelerated or decelerated by controlling movement of the track so a portion of the track where the mass is sensed to be located is moved inwardly (for acceleration) or outwardly (for deceleration) along a local radius of curvature of the track.

Abstract: A vehicle washing machine is disclosed having an inverted U-shaped housing mounted for movement lengthwise of a stationary vehicle and return movement to an initial reference position during a vehicle washing cycle of the machine. The housing includes first mechanism comprising a vertically movable and rotatable pod depending from a bridge portion of the housing and having horizontally reciprocative nozzles mounted thereon for successively applying a cleaning solution and pressurized rinse water to a front end, top, and rear end of the vehicle, and second mechanism associated with opposite legs of the housing and having vertically reciprocative nozzles mounted thereon for successively applying a cleaning solution and pressurized rinse water to opposite sides of the vehicle. The machine includes a relay logic system for controlling the vehicle washing cycle.

Abstract: A mechanism is used for transmitting the power output of a power drive source such as a wind-up music to an ornament supported thereon. The transmission mechanism has a first drive wheel mounted on a power output shaft of the power drive source at one end of the power output shaft. A drive gear is mounted on the power output shaft of the power drive source at the other end of the power output shaft. A second frame is fixed to the first frame sopporting the power drive source. An idler gear is supported on the second frame by a first shaft and meshed with the drive gear. An output gear is supported on the second frame at the far side of the drive gear and meshed with the idler gear. A second drive wheel is supported on the second frame and securely connected to the output gear through a second shaft. A support plate having a hole formed thereon is pivoted to the first drive wheel at one end and the second drive wheel at the other end.

Abstract: A device for producing drilled holes with an undercut in facing panels includes a drill bit with a drill head that produces an undercut, and a drilling table for supporting a facing panel in which the drilled holes with an undercut are to be produced and displaceable in a plane of the drilling table. A trunnion projecting from a rotatable base member and engaging a bearing secured to the drilling table is movable between a first position in which the trunnion axis coincides with the axis of rotation of the base member, and a second position in which the trunnion axis is eccentric to the axis of rotation of the base member to effect swiveling of the drilling plate when the rotatable base is driven rotatably.The device has a mechanism for moving the trunnion between the first and second positions including a lever pivotally mounted on the base member, the trunnion being mounted on the lever, and a piston-cylinder drive secured to the base member for pivoting the lever.

Abstract: The invention relates to the driving mechanism of multi-action doll. The driving mechanism comprises an eccentric roller, a cross-shaped driving component and several driving gears. The cross-shaped driving component has a rectangular hole which accommodates the eccentric roller which moves the cross-shaped driving component back and forth in a linear direction when the roller rotates in the hole. The cross-shaped driving component has racks that mesh with and rotate the driving gears when the driving component is moved by the eccentric roller. Rotation of the gears also rotates shafts on the gears which convey motion to selected portions of a moveable doll.

Abstract: An apparatus for providing linear motion in two opposed directions and circular motion in a first direction using a single drive motor.

Abstract: A rotatable turntable for vortexing reactants comprises a vortexing plate which is rotatable. The motor drives for vortexing and rotation are stationary such that simple mechanical and electrical connection relative to the peripheral supports and to the vortexing plate can be achieved. A vortexing work station located in alignment with the turntable operates in synchronism with the turntable. Reactants at any radial reactant station on the vortexing plate can be withdrawn from and located onto the turntable at any radial location when the turntable stops rotation. The radial position of the turntable in relation to the outside vortexing and non-vortexing periphery remains relatively aligned.

Abstract: A wobble device is provided including a circular platform, a structure for pivoting the platform to achieve a wobbling movement, a shaft transverse to and positioned in a center of the platform, a moveable carriage rotatably attached through an arm to the shaft, a roller structure for moving the carriage on an upper surface of the platform, and a support frame below the platform. A forcing structure attached to a plurality of extension members downwardly directs the platform tilting an end of the platform toward the support frame. As the platform inclines towards the forcing structure, the carriage also begins to rotate. Once in motion, only a minimum amount of electrical energy is needed to maintain the wobble. As the carriage rotates, it turns a spur gear system attached to the center shaft. This rotational movement is then transferred through the gear mechanism to an armature of an electrical generator fastened to the platform upper surface.

Abstract: A wobble drive mechanism for a translationally moving structural part includes a wobble rod which is moved by way of a crank drive mechanism. The wobble rod includes a spherical section at one end thereof that is seated in a bearing bush of a crank. At its opposite end, the wobble rod includes a second spherical section that is seated in a stationary structural part. A third spherical section is positioned between the two ends of the wobble rod and is seated in the translationally moving structural part. The spherical sections are supported in hemispherical articulation sockets located in the manner of a mirror image in the two structural parts. A spring device can be provided to ensure full contact of the spherical sections in their respective articulation sockets.

Abstract: A mechanical transmission device to provide selective gear speed output from a constant input. A variation gear affixed to an adjustable crank determines output speed of a free floating following gear and connecting rod assembly dependent on the relative orbit size of the variation gear as determined by the crank. The orbit size is adjusted by the angular inclination of the adjustable crank.

Abstract: Apparatus is provided for simultaneously rotating a plurality of parallel shafts connected, for example, to an array of rf switches that feed energy to or from an array of antenna feed horns. Each shaft is connected by a separate crank to a planar drive plate that is controllable moved relative to the switches in an orbiting fashion, to rotate the shafts in unison. The drive plate is controllably moved by a motor drive system that includes an orbiting motor secured to the plate and a base motor secured to a fixed substrate that houses the switches. The output shafts of the two motors are coupled together such that operation of either motor moves the orbiting motor, and thus the drive plate, in an orbiting motion about the base motor and substrate.

Abstract: A method and apparatus are provided for applying multidirectional vibrations to a resilient support. The excentric of the unidirectional vibration generator cooperates with a spherical shaped member mounted for free rotation on the lower face of the vibrating table connected to the base through springs. The unidirectional vibration generator is carried by a plate parallel to the vibrating table and which is rotated about an axis X--X which is perpendicular thereto, under the action of a motor. This rotation of the unidirectional vibration generator ensures the application of multidirectional vibrations to said table.

Abstract: An orbital table assembly having a top plate which can be made to orbit or translate in a path without rotating, and having a fixed base plate under said top plate and a linkage plate between the two other plates, while an orbiting cam secured to the top plate imparts orbital motion thereto. A first set of arms is provided to secure the linkage plate to the base plate to prevent rotation of the linkage plate while permitting linear lateral movement in one direction only, and a second set of arms is provided secured to secure the top plate to said linkage plate to prevent rotation of said top plate while permitting linear lateral movement in a single direction perpendicular to the aforesaid direction.

Abstract: A device for obtaining a directional force from a rotary motion has a frame rotating about a longtiudinal axis at a selected angular speed. A weight is connected to the frame and rotates about a transverse axis at the same angular speed. When the weight has transversed 180.degree., the frame itself will have rotated through 180.degree., so that the weight will return to its original position on the same side of the apparatus as it transversed in the first half cycle. The resultant centrifugal forces all act to one side of the apparatus, producing a unidirectional thrust.

Abstract: In the embodiment of the invention described in the specification, a drive assembly for an eccentrically driven mass has a drive shaft which drives the mass by a first eccentric device and a secondary shaft, driven synchronously with the drive shaft, which drives a second eccentric device spaced from the first eccentric device so as to guide the mass in a constrained manner. The connection between the second eccentric device and the mass includes a resilient mounting. In order to avoid, or at least reduce, sinusoidally varying stresses imposed on the resilient mounting during operation as a result of deflection of the drive shaft, the eccentricity of the second eccentric device is larger than the eccentricity of the first eccentric device by at least a portion of the magnitude of the maximum deflection of the drive shaft in the region of the mass occurring during operation.

Abstract: The diameter of an orbiting scroll plate is increased and the periphery of the plate is notched or scalloped to clear the bolt bosses or spacers located between the fixed scroll and crankcase. The bolt bosses act as guides for the notches in the orbiting scroll plate to thereby create an anti-rotation mechanism. Because the anti-rotation structure is on the periphery of the plate, a greater thrust surface is available.