Abstract: An electrically powered hammer comprising a hollow spindle within which spindle is reciprocatingly mounted a piston, a ram, a beatpiece having an increased external diameter mid-portion and located within the spindle between the ram and the tool or bit, a two part sleeve arrangement located within the spindle and including an increased internal diameter mid-portion for receiving the increased external diameter portion of the beatpiece and a reduced internal diameter forward and rearward portion for guiding the forward and rearward ends respectively of the beatpiece and where the sleeve arrangement includes a forward sleeve and a rearward sleeve which are both guided with tight radial tolerances and with a slight axial play within and by the spindle and the forward axial movement of the forward sleeve is limited by a reduced diameter portion of the spindle and the forward axial movement of the rearward sleeve is limited by the forward sleeve.

Abstract: A method for manufacturing an EMI-shielding assembly having a substrate comprises the steps of: (a) providing oxygen plasma to clean the substrate; (b) ion plating the cleaned substrate with an adhesion layer comprising nickel; (c) ion plating the plated substrate with a metal shielding layer comprising copper; and (d) ion plating the plated substrate with a corrosion-resistant layer comprising stainless steel. The EMI-shielding assembly made by this method has a very firm adhesion between the substrate and the metal layers. Moreover, the EMI-shielding assembly has superb characterisitics for shielding EMI since the substrate has a more uniform shielding layer. In addition, this method is very suitable for making an EMI-shielding object which has an irregular shape.

Abstract: An apparatus and method for providing RF shielding for performing nuclear magnetic resonance (“NMR”) procedures, comprising a radio-opaque holder in combination with radio-opaque magnet components to form an RF shield around a patient undergoing an NMR procedure. In embodiments, a radio-opaque holder having a radio-opaque bottom portion and a radio-opaque canopy is adjoined to an NMR magnet having a radio-opaque cryostat and a radio-opaque service end cap to form an RF shield. A patient is placed on a patient support unit located in the holder bottom portion. The patient support unit, including the patient, is then inserted into the cavity of the NMR magnet and a canopy is placed on top of the bottom portion of the holder. An RF shield is thus created comprising the canopy, the bottom portion, the cryostat of the magnet, and an end cap on the service end of the magnet.

Abstract: A clamp (40) for attaching a vibration damper to an energized suspended conductor (98) includes a base (42) having a first clamp member (46) with first and second extension sections (50, 52). The clamp (40) further includes a second clamp member (56) positioned between the extension sections (50, 52), and an eyebolt (58) for securing the second clamp member (56), to the first clamp member (46). The extension sections (50, 52) continuously abut the second clamp member (56) to prevent its rotation about the eyebolt (58). During installation, the eyebolt (58) is captured by a hook member (92) of shotgun stick (94) and a single lineman secures the vibration damper to the conductor (98).

Abstract: A vault is constructed for mounting in the ground and formed with at least one wall defining an interior space. At least one cross-connect panel is mounted on the wall in stationery relation thereto. Signal conductors are attached to the panel and extend through the wall. A top cover enables ingress to and digress from the interior space by service personnel.

Abstract: A method for removing an image sensor from a printed circuit board. The printed circuit board has a first surface and a second surface. The image sensor is welded to the first surface, and the method includes the steps of: supplying a hot air stream to the first surface of the printed circuit board so as to distribute the hot air stream over a periphery of the image sensor and to melt solder; and providing a heater to heat the second surface of the printed circuit board and to raise a temperature of the second surface of the printed circuit board.

Abstract: A circuit module includes an insulating base including a first wiring pattern and a cavity; at least one first electrical component disposed in the cavity; and a lid including a second wiring pattern. The insulating base includes a circuit board composed of laminated substrates and a sidewall protruding from the board surface of the circuit board and forming the cavity together with the circuit board, and the lid has at least one second electrical component fixed thereto. Also, in a state in which the second electrical component is located in the cavity, the lid is fixed on the upper surface of the sidewall so as to cover the cavity, and the first and second wiring patterns are connected to each other with at least one connecting conductor.

Abstract: A coaxial feedthrough connector for connecting an RF signal through a wall in a hazardous environment and particularly to an antenna. The connector has a base with an axial passage. A coaxial transmission line extends through the passage and a nonconductive, preferably silicone sealing compound fills at least a longitudinal segment of the passage and sealingly engages both the transmission line and the interior surface of the passage. A sealant is used that is approved for use at the location in a hazardous environment where it will be used.

Abstract: A method of joining the interfacing ends of cables, one to another, wherein each comprises a plurality of conductor strands, comprising (i) providing each of the ends with an enlarged terminal portion of greater diameter than the cable adjacent the end, (ii) inserting the ends into a connecting tube having an outer layer of an explosive charge, and (iii) detonating the explosive layer so as to compress the connecting tube around the conductor strands. The method offers a cheaper, faster and simpler method of joining a bundle of wires and the like than prior art methods.

Abstract: A shielded electrical wire construction, comprising an insulated wire, a conductive coating surrounding the insulated wire to provide a positive attenuation of and protection from electromagnetic and radio frequency interference. The conductive coating comprises a metallic powder dispersed in a PTFE solution. An outer insulation coating formed of PTFE surrounds the conductive coating.

Abstract: An electrical cable having at least one core including a conductor and an insulation surrounding the conductor and having at least two insulation layers. A first one of the layers is a silicone rubber compound and a second one of the layers is an ethylene(C2)-alkylene(Cx)-copolymer or terpolymer mixture adapted to have properties corresponding to those of a hardgrade-ethylene-propylene-rubber (H-EPR). The second layer can be a hardgrade-EPR. Such a cable construction in particular enables reduction of the cable diameter while still being capable of sustaining a burn test according to DIN 4102 Section.

Abstract: Disclosed is a cable installation in an office layout having a raised floor forming a plenum having air conditioned air charged therein. The conditioned air is lead through the floor by way of flexible tubes that are guided to the various office stations located above the floor. Wherever needed, the flexible tubes are connected above the floor and below the floor to rigid tubes that are located in the replaceable tiles in the raised floor. This installation requires that various cables also must be installed. It has been found that the most convenient way to accomplish this is to lead the cables through the flexible tubes to wherever they are needed. The cables are conveniently located under the floor. The rigid tube installed in the tile of the floor has a lower rigid extension. An opening is placed laterally into the rigid tube, a special plate is placed to cover the opening including a sealing element.

Abstract: A wiring board that allows the high-density connection with a plurality of circuit boards within a limited area, a manufacturing method for the same and electronic equipment using the same are provided. A wiring board includes: a plurality of conductive layers each including one or more wirings for transmitting signals; and a plurality of insulation layers for insulating the respective conductive layers. The conductive layers and the insulation layers are laminated alternately, and each of the plurality of conductive layers is provided with a terminal at at least one of both ends. The terminals are formed stepwise and separated by the insulation layers in a cross-sectional shape of a lamination structure of the conductive layers and the insulation layers.

Abstract: Manufacturing of miniaturised three-dimensional electric components are presented, as well as components manufactured by the methods. The manufacturing methods comprise micro-replication of at least one master structure, e.g. via a mould structure, in at least one polymer layer onto which layer at least one conductive path is provided.

Abstract: A structure and method for forming a tamper respondent electronic circuit enclosure that includes an integrated circuit structure, a mesh structure surrounding the integrated circuit structure, and a sealed enclosure surrounding the mesh structure. The mesh structure includes a layer of flexible dielectric having a first side and a second side, a screen-printed pattern of flexible electrically conductive first circuit lines forming a first resistor network on the first side, and a photo lithographically-formed pattern of flexible electrically conductive second circuit lines forming a second resistor network on the second side.

Abstract: A multilayer wiring board assembly, a multilayer wiring board assembly component and a method of manufacture thereof are described in which it is possible to easily laminate together flexible FPCs having highly packing densities by via-on-via and chip-on-via. The multilayer wiring board assembly is laminated by laminating together a plurality of multilayer wiring board assembly components, each of which is made by preparing a copper plated resin film 10 made of a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste filler embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste filler being projected from said resin film.

Abstract: A method and apparatus for forming an in situ borehole liner in which a laser beam from a laser energy assembly disposed within a transparent drill head enclosure of a drill head assembly is directed into a rock formation to be drilled and a portion of the rock formation is melted, forming molten rock. The drill head assembly is directed into the molten rock forming a borehole having a borehole wall. At least one air stream from the drill head assembly is directed into the molten rock forming the molten rock against the borehole wall after which the molten rock against the borehole wall is cooled, forming a borehole liner.

Abstract: An automatic drilling system is disclosed which includes an electric servo motor operatively coupled to a winch brake control, a servo controller operatively coupled to the servo motor, and a drum position encoder rotationally coupled to a winch drum. The controller is adapted to operate the servo motor in response to measurements of position made by the encoder so that a selected rate of rotation of the drum is maintained.

Abstract: A well drilling system includes a platform mounted on the ground, a tubular sleeve mounted movably on the platform, a drilling device inserted into the sleeve, and a circulation device. The drilling device includes a support seat connected detachably to a lower end of the sleeve, a drilling head mounted rotatably on the support seat, and at least one powered actuator connected to the support seat and the drilling head to actuate the drilling head to rotate relative to the support seat. The circulation device includes a pipe, and is mounted inside the sleeve for removing soil out of the sleeve.

Abstract: The invention provides an under-reamer tool and method for creating a large diameter volume within a well bore. The under-reamer tool includes a mandrel for connection to a drill pipe and for supporting a torque arm assembly and hole initiator assembly. The hole initiator assembly, upon activation, creates a nominally larger diameter volume that triggers activation of the torque arm assembly thereby allowing the torque arm assembly to extend to cut away a cutting face thereby creating a significantly larger diameter volume within the wellbore as the under-reamer is rotated within the wellbore. Reverse circulation of a circulation medium in combination with the geometry of the cutting face provides effective removal of the cuttings from the cutting face.

Abstract: An assembly for drilling a deviated borehole includes a bottom hole assembly connected to a string of coiled tubing and includes a bit driven by a downhole motor powered by drilling fluids. A surface pump pumps the drilling fluids downhole through a cross valve to provide a first path directing drilling fluids down the coiled tubing flowbore and a second path directing drilling fluids down the annulus. The bottom hole assembly has a downhole valve allowing flow between the flowbore and the annulus. A first flow passageway directs drilling fluids down the coiled tubing flow bore and then up the annulus and a second flow passageway directs drilling fluids down the annulus and the up the flowbore. The bottom hole assembly includes a subsurface pump capable of pumping drilling fluids from the second fluid passageway to the surface. The bottom hole assembly includes an electric motor to rotate the subsurface pump and the motor is provided with power conduits embedded in a wall of the coiled tubing.

Abstract: A drill bit shaft member for tapping a hole in a blast furnace is disclosed. The drill bit shaft member comprises an elongate rod, a first fluid pressure inlet, a second fluid pressure inlet, a chamber in fluid communication with the first fluid pressure inlet and the second fluid pressure inlet, and an outlet in fluid communication with the chamber. A liquid and a gas are combined in the drill bit shaft member to form a mist to provide cooling for the drill bit shaft member. By cooling the drill bit shaft member, certain components that would normally be destroyed may be re-used.

Abstract: The drill string element has at least one bearing zone for bearing against the wall of the borehole during drilling. The bearing zone comprises at least one bearing segment extending in the axial direction and having an outside surface that is cylindrical and of constant diameter greater than the diameter of any other portion of the surface of the element, and also having a guide zone that is circularly symmetrical about the axis of the drill string element. The bearing zone preferably also has a drilling fluid activation zone extending axially in a disposition adjacent to the bearing segment. The guide zone presents a radius of curvature not less than one-third the outside diameter of the bearing segment.

Abstract: A printed circuit board (PCB) is provided for use with electrical apparatus. The PCB has a body with a surface provided for the location of electrical components thereon and electrically conductive tracks are provided for electrically connecting the component in a required arrangement. A portion of the PCB body has a test port thereon for allowing testing of functions of the PCB, electrical conductive tracks and/or electrical components. The testing portion of the PCB body provided with the test ports is detachably attached to the PCB body to allow removal therefrom.

Abstract: A weight scale for a extracorporeal pump controller including: a load cell mounted to a support housing; a spring coupled to the load cell to apply a force to the load cell; a scale beam connected to the spring and at a proximal end connected to the support housing, and an overload protection bore having an aperture through which extends said beam and said aperture having at least one edge in a path of said beam, wherein said edge terminates said path and the beam has maximum rated load position in the path before the edge.

Abstract: Disclosed is a driving apparatus for a robot cleaner enabling drive wheels to be in contact with a floor all the time. The driving apparatus for a robot cleaner includes a robot cleaner main body, driving motors mounted in the robot cleaner main body, and for transferring power to drive wheels, driving motor housings hinged with the robot cleaner main body, and for accommodating the driving motors therein, and pressure members disposed between the robot cleaner main body and the driving motor housings, and for pressing the driving motor housings. Accordingly, the driving motor housings are mounted to rotate about the center of the rotation hinges so that the drive wheels come in contact with the floor all the time, preventing the drive wheels from being lifted over the floor and making lost rotations due to curved portions of the floor or obstacles.

Abstract: There are two basic methods of steering a wheeled vehicle. One method is to turn one or more steerable wheels. The other is to drive one or more left hand wheels independently of one or more right hand wheels. Traditional vehicles address the potential conflict between to two steering systems by either disabling one system or by causing one to overpower the other. This leads to skidding or scuffing problems respectively. In the present invention both steering systems are enabled but are integrated by means of an on board computer so that they always act in unison. This mutual reinforcement will allow the invention to operate safely on steep or slippery slopes while minimising fuel consumption and ground damage. The invention will also be more manoeuvrable than traditional vehicles since it is capable of both pure rotation and pure translation or any combination of rotation and translation.

Abstract: An electrical distribution system for a vehicle having electrical devices includes at least one junction box and a plurality of terminals interconnected by at least one conductive path. The electrical distribution system operatively interconnects the electrical devices when the electrical devices are appropriately connected to the electrical distribution system via the terminals. A method for advantageously using an electrical distribution system having sufficient terminals and sufficient conductive paths to accommodate a plurality of vehicle electrical device combinations is also provided.

Abstract: The invention comprises twin double-acting electrical machinery assembly, each being of interactive rotational type, and such that the interactive rotational assembly on the non-outputting side of either double-acting electrical machinery assembly gets coupled to its counterpart interactively by slidably applied damping effect or alternatively by solid coupling technology.

Abstract: To simplify wire harness including power cables and reduce power loss in an engine-motor hybrid vehicle drive train system.

Abstract: Device and method for operation of at least one electrical machine for a motor vehicle. In order to coordinate torque requirements for the propulsion system and voltage requirements for the vehicle power supply system and at least one battery for the vehicle power supply system, a voltage reference variable is formed for the voltage requirements for the vehicle power supply system, and a torque reference variable is formed for the torque requirements of the propulsion system. The voltage reference variable is limited by upper and lower torque limit values which must not be overshot or undershot in the event of changes to the voltage reference variable. The torque reference variable is limited by voltage limit values which must not be overshot or undershot in the event of torque changes.

Abstract: An off-road vehicle has a frame with a floorboard extending laterally over a middle region of the frame. The floorboard has a upward projection that defines a tunnel. At least a portion of an air intake system of an engine of the vehicle is positioned within the tunnel. A foot pedal is disposed in front of a seat such that a driver of the vehicle can operate the pedal by foot. The tunnel has a surface that is laterally adjacent the foot pedal such that the foot of a driver can simultaneously contact the surface and the foot pedal.

Abstract: An off-road vehicle includes a frame and a plurality of wheels. An engine powers the wheels. An air intake system supplies air to the engine. The air intake system has an air inlet through which ambient air enters the intake system. The air inlet is positioned higher than the wheels. An air intake duct extends rearward to the engine from the air inlet. At least a portion of the air intake duct is positioned lower than the tops of the wheels.

Abstract: A front grill impact-absorbing structure has a load-transmitting member (90) which retreats together with a front grill (30) when a collision force (F1) acts on the front grill from the front. By the load-transmitting member retreating together with the front grill, the collision force is transmitted to a water-cooled engine radiator (20) inside an engine compartment (11). In the initial state of the collision, the radiator absorbs the collision force and moderates the collision force.

Abstract: A traction unit capable of traversing and turning on surfaces that include compound curves like the surface of a sphere or are inverted like a ceiling. The traction unit includes a plurality of trucks operable to propel the unit across a surface and a plurality of adherence members operable to releasably secure the unit to the surface. In operation, the adherence members cyclically attach to and release from the surface as the trucks propel the unit across the surface. Within each cycle, after the unit has traveled a predetermined distance relative to an attached member, the member releases the surface and reattaches to the surface at a different point.

Abstract: A drive control apparatus for a vehicle having an accelerator pedal and a brake pedal both of which are operable by a driver of the vehicle, and a power source. The drive control apparatus includes a vehicle speed measuring device which measures a vehicle speed, a control operation switching device which places the drive control apparatus in an operating state upon receiving an operation from the driver, a vehicle speed adjusting device which is placed in an operating state upon receiving a command from the control operation switching device, and which, during the operating state, automatically adjusts the vehicle speed measured by the vehicle speed measuring device, independently from driver's operations of the accelerator pedal and of the brake pedal, so that a target vehicle speed is achieved, and a target vehicle speed changing device which changes the target vehicle speed depending on predetermined driver's operations of the accelerator pedal or of the brake pedal.

Abstract: A vehicle comprises a frame and a slide rail pivotally coupled to the frame. A spring member urges the slide rail in a direction away from the frame. The spring member has a first portion mounted to the frame and a second portion supported on the slide rail at a first spring support position in a first configuration. A spring support is coupled to the vehicle at a second spring support position and is arranged to engage the spring member upon deflection of the slide rail in a second configuration. The vehicle suspension system becomes increasingly stiffer as the deflection of the slide rail increases, to contribute to a more comfortable ride and to reduce the risk of bottoming-out.

Abstract: A vehicle comprises a frame and a slide rail disposed below the frame for guiding a drive track along a road surface. An arm has a first portion pivotally coupled to the frame at a frame pivot location and a second portion pivotally coupled to the slide rail at a rail pivot location. Vertical movement of the slide rail causes a length of the arm between the frame pivot location and the rail pivot location to extend or contract. The vehicle suspension system becomes increasingly stiffer as the deflection of the slide rail increases, to contribute to a more comfortable ride and to reduce the risk of bottoming-out.

Abstract: A bicycle power supply apparatus comprises a battery unit; a bicycle condition detecting unit that detects when a bicycle is in a selected condition that ordinarily does not require drawing current from the battery unit for powering a current drawing element; and a current drawing unit that causes current to be drawn from the battery unit when the bicycle condition detecting unit detects the selected condition.

Abstract: An auxiliary wheel conversion assembly for a motorcycle comprises a frame having side members on opposite sides of a receiving space to receive the rear drive wheel of the motorcycle when connected thereto. The assembly has a pair of wheels having a common axis but each being independently mounted to a side member opposite the receiving space, and the pair of wheels substantially in contact with the ground surface at all speeds and is not adapted to selectively lift the wheels. The frame also is substantially at or below the axis of rotation of the rear wheel of the motorcycle.

Abstract: A articulate vehicle comprises a first frame disposed at one of front and rear portions of the vehicle and a second frame disposed at the other of front and rear portions of the vehicle. The first frame supports a first transaxle apparatus supporting a first axle. The second frame supports a second transaxle apparatus supporting a second axle. Proximal ends of the frames with respect to the vehicle are coupled to each other through a coupling part so that the first and second frames are rotatable relative to each other around a vertical axis according to steering operation. An engine is mounted on the first frame. A first hydraulic motor is integrally assembled in the first transaxle apparatus so as to drive the first axle. A working vehicle is equipped at a distal side of the second frame with respect to the vehicle. A second hydraulic motor is integrally assembled in the second transaxle apparatus so as to drive the second axle.

Abstract: An off-road vehicle has front and rear wheels. An engine unit powers the wheels. The engine unit has an output shaft. A front differential is coupled with the front wheels. The front differential has a front input shaft. A front drive connects the output shaft and the front input shaft with each other. The front differential can operate in one of three modes: an unlocked mode, a locked mode and a disabled mode. A rear differential is coupled with the rear wheels. The rear differential mechanism has a rear input shaft. A rear drive connects the output shaft and the rear input shaft. The rear differential can operated in at least two modes: an unlocked mode and a locked mode. In one embodiment, the front differential is allowed to be locked only when the rear differential is locked.

Abstract: A vehicle occupant gas-contact restraining system including at least one gas generator or gas source located within a vehicle and adapted to discharge a gas flow which flows between a seat back of a vehicle seat and a vehicle occupant seated on the vehicle seat when the gas generator or gas source is activated or actuated during a vehicle collision. The gas flow is adapted to come into contact with the occupant's body to form an enlarged occupant-contact area, and to generate a force which pushes or attracts the vehicle occupant toward the seat back of the vehicle seat, thereby reducing an inertial force of the occupant's body and restraining the vehicle occupant from forward inertial movement during the vehicle collision. The entire process of restraining the vehicle occupant takes place in a fraction of a second, and it will not interfere with the driver's visibility or the ability to steer or operate other controls.

Abstract: A method for actuating a reversible vehicle occupant protection device in a motor vehicle having a driving state sensor system and a reversible vehicle occupant protection device. The reversible vehicle occupant protection device can be triggered before the collision time and as a result moved into an effective position. For this purpose, the driving state data are monitored with respect to a state of emergency braking, and when the state of emergency braking is detected the vehicle occupant protection system is actuated. In addition, a state of oversteering and a state of understeering are determined by the data processing device. The reversible vehicle occupant protection system is actuated when the data processing device detects the state of emergency braking and/or the state of oversteering and/or the state of understeering.

Abstract: A car-mounted device control system is obtained which can prevent or lessen erroneous operation of operating portions, switches, and the like during rotation of a steering wheel. When a CPU 16 starts up a function switching program from a storage medium 24 on the basis of an inputted touch signal, a present center control unit 10 compares a comparative rotational position R0 read from the storage medium 24 and a rotational position detection signal R from a steering angle sensor 32. As a result, when the rotational position detection signal R exceeds the comparative rotational position R0, a touch signal and a click signal are cancelled. Thus, inadvertent switching of functions due to a body touching a controller 70 while a steering wheel 22 is rotated can be prevented.

Abstract: A possibility for controlling and supplying energy to a larger number of restraint means components in a vehicle seat that can be installed in variable fashion, this possibility being able to be realized using a constructively simple and robust electrical connection, so that this connection in particular also withstands the mechanical stresses that occur during the installation and removal of the vehicle seat. For this purpose, the vehicle seat is equipped with at least one system bus for controlling and supplying energy to the individual restraint means components of the vehicle seat. In addition, means are provided for the electrical contacting of the system bus during the installation of the vehicle seat.

Abstract: A mounting structure for a vehicle firmly and stably supports an engine or a transmission at a lateral side of an engine room by using a chassis bracket and a mounting bracket, thereby effectively minimizing vibration transfer from the engine or the transmission to the car body.

Abstract: An off-road vehicle includes a frame and wheels. An engine of the vehicle has a crankshaft. A transmission transmits the rotation of the crankshaft to the wheels. A housing houses a transmission mechanism of the transmission. The housing has an air inlet duct through which ambient air enters the housing and an air outlet duct through which the air leaves the housing. The air inlet duct has an inlet opening. The outlet duct has an outlet opening. The inlet and outlet openings are positioned higher than the wheels.

Abstract: A frame structure and a method of manufacturing a body frame that is divided into small assemblies to facilitate the carriage and storage of articles and individuals and the manufacturing efficiency. A body frame is divided into three, namely, a front assembly having a closed loop structure, an engine support system assembly having a closed loop structure and a rear suspension support system assembly having a closed loop structure. The front assembly and the rear suspension support system assembly are connected to the engine support system assembly to form the body frame. The small assemblies to have a closed loop structure whereby the rigidity is enhanced, and the shape is also stabilized. Therefore, the accuracy management can be performed.

Abstract: An apparatus (10) for turning steerable wheels of a vehicle comprises a housing (14) that defines a fluid chamber (24). A rack bar (26) extends longitudinally through the housing (14) and is connectable with the steerable wheels of the vehicle. The rack bar (26) is movable relative to the housing (14) for turning the steerable wheels. A piston assembly (34) is fixedly attached to the rack bar (26) and sealingly engages the housing (14). The piston assembly (34) divides the fluid chamber (24) into first and second chamber portions (40 and 42). A fluid source (80) directs fluid toward one of the first and second chamber portions (40 or 42) for creating a differential pressure between the first and second chamber portions (40 and 42). The piston assembly (34) and the rack bar (26) move relative to the housing (14) in response to the differential pressure. The piston assembly (34) includes structure (132) for dampening fluid pulsations emanating from the fluid source (80).