Abstract: The invention provides a fixed cutter drill bit for drilling through unconsolidated, highly abrasive formations. The bit includes a bit body having a cutting face and a side portion. The bit body comprising carbide matrix material. A plurality of blades azimuthally spaced about the cutting face and a plurality of cutters disposed along the blades. At least one gage pad is disposed along a side of the bit body and includes wear resistant gage elements formed of a material more wear resistant than the matrix material forming a portion of the gage pad. The wear resistant elements have a rounded surface and are embedded in gage pad material proximal a leading edge of the gage pad to provide a rounded wear-resistant edge or surface proximal the leading edge.

Abstract: A fixed cutter drill bit includes a plurality of gage pads, where certain of the gage pads have an active cutting region adjacent to the end of the gage pad adjacent to the bit face, and a passive region at the end of the gage pad adjacent to the pin-end of the bit. The active regions include forward-facing cutter elements. Other gage pads include an active region on the end adjacent to the pin-end, and a passive region on the gage pad end adjacent to the bit face. The passive and active regions have lengths within the range of 40 to 60 percent of the total axial length of the gage pads. A passive gage pad is positioned on the bit between the gage pads having both active and passive regions.

Abstract: A combined luggage and scale comprising a luggage platform for holding a plurality of items, an attachable scale for measuring the weigh of the items and a readout for reading the weight.

Abstract: A traveling system for heavy construction equipment is disclosed, which can prevent a flow rate of a hydraulic fluid to be supplied to a traveling spool from being suddenly decreased when a traveling device and a working device are simultaneously operated, and thus can minimize operation shock due to sudden reduction in traveling speed. The traveling system includes a sensing device that detects manipulation of an operation lever of the working device or manipulation of a traveling pedal installed in the operation lever or the traveling pedal and outputs an electric signal to a controller in a specific operation mode. The traveling system also includes first and second variable displacement hydraulic pumps that are driven by an engine and have the same maximum capacity and a main control valve that controls the flow direction of a hydraulic fluid discharged from the hydraulic pumps.

Abstract: A mobile staging system includes a readily movable framework and a motor-driven scooter joined to one another for relative pivotable movement. Means for controlling movement of the scooter is readily accessible from a worker's platform on the staging.

Abstract: A hybrid vehicle propulsion system is disclosed comprising an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherein the engine is configured to supply an engine output; a motor configured to selectively supply or absorb a secondary output; an energy storage device configured to selectively store at least a portion of the engine output and selectively supply energy to the vehicle; and a control system configured to control at least the engine, the motor, and the energy storage device, wherein the control system is configured to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the energy storage device.

Abstract: A hybrid vehicle propulsion system is disclosed comprising an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherein the engine is configured to supply an engine output; a motor configured to selectively supply or absorb a secondary output; an energy storage device configured to selectively store at least a portion of the engine output and selectively supply energy to the vehicle; a lean NOx trap configured to store NOx produced by the engine; and a controller configured to control at least the engine, the motor, and the energy storage device, wherein the controller is configured to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the lean NOx trap.

Abstract: In a drive control system for a hybrid vehicle, the electric power generated by an alternator driven by an engine and the electric power regenerated by a motor-generator are stored in a battery. The battery discharges electric energy to drive the motor-generator. An ECU calculates fuel consumption of the engine and fuel consumption of the motor-generator, and determines a distribution of motive power between the engine and the motor-generator from the fuel consumptions. The ECU calculates fuel consumption contributing to the electric energy stored in the battery, and then calculates the fuel consumption of the motor-generator by reflecting the contributing fuel consumption in it.

Abstract: A hybrid electric vehicle is arranged such that a driving force of an electric motor can be transmitted to driving wheels, and a rotary shaft of the motor can be coupled with an output shaft of an engine. When a starting switch is switched from the first to the second position, a start control unit starts power supply from a battery to a power control unit. When the starting switch is switched from the second to the third position, the start control unit starts the engine by the electric motor if a control of the power supply to the electric motor can be executed by the power control unit, and, on the other hand, starts the engine by a starter motor if the control of the power supply to the electric motor is not possible to be executed by the power control unit.

Abstract: Apparatus for installation on a motorcycle which is capable of shielding one or more riders thereof from heat generated during motor operation. In preferred embodiments, apparatus with a plurality of detachable shield panels which are capable of protecting one or more riders from excess heat generated by the operation of a motorcycle, and, conversely, in which the shield panels can be removed to provide beneficial heat to the rider and/or passenger when desired.

Abstract: A protection system for an accelerator and brake (A&B) assembly of a utility vehicle is provided. The protection system comprises a brake pedal (BP) protective boot that conforms with and sealingly fits around a brake pedal arm. The protection system additionally includes an accelerator pedal (AP) protective boot that conforms with and sealingly fits around an accelerator pedal arm.

Abstract: A powered snowboard having a drive assembly mounted thereon, the drive assembly including a frame, a track assembly having a track suspended over multiple wheels, the track assembly being supported in the frame such that it is able to travel in a vertical direction as well as pivot about an axis, and a motor operatively engaged with the track such that it drives the track thus propelling the snowboard. A cutout is formed in the snowboard through which the track assembly engages the snow or ice below the snowboard, and the track assembly is biased against the snow or ice to maintain a constant contact with the snow or ice during use.

Abstract: According to a present powertrain, a first rotation shaft serving as an input shaft of a front side gear mechanism is located in a portion of a vehicle lower than a second rotation shaft serving as an output shaft, so that a crankshaft of an engine provided coaxially with the first rotation shaft is located in a portion of the vehicle lower than in a conventional example. Solely the engine shaving a heavy mass is thus disposed in a lower portion, so as to achieve a lower position of the center of gravity of the vehicle. In this manner, a powertrain having a layout structure attaining lower center of gravity as well as high rigidity of a body and improvement in aerodynamic characteristics is provided.

Abstract: A hybrid electric vehicle is arranged such that a driving force of an engine and a driving force of an electric motor can be transmitted to driving wheels through a transmission and that the engine and the transmission can be mechanically connected and disconnected by means of a clutch. When an upper limit decelerating torque generable by the electric motor is equal to or greater than a requested decelerating torque, a vehicle ECU disengages the clutch and controls the electric motor to generate the requested decelerating torque. Meanwhile, when the upper limit decelerating torque is smaller than the requested decelerating torque, the vehicle ECU engages the clutch and controls the engine and the electric motor so that the sum of a decelerating torque generated by the engine and a decelerating torque generated by the electric motor is equal to the requested decelerating torque.

Abstract: In a power steering system, the steering state of wheels is detected based on the steering speed to judge as to whether the steering state is in turning of the steering wheel or holding of steering speed is the steering wheels. At the time of the steering operation state, the control is executed so that a difference between a torque command value to an electric motor and the actual torque thereof will become smaller. Also, at the time of the holding operation state, the control is executed so that a difference between the revolution speed of the electric motor and a revolution-speed command value thereto will become smaller.

Abstract: An electric power steering apparatus requires no external connecting member connecting between a power main body and a control main body, and hence can be reduced in size and cost, and the reliability of electrical connection between the power main body and the control main body can be improved. High current parts constituting the power main body and low current parts constituting the control main body are mounted on opposite sides of a circuit board, and are electrically connected with one another via conductor layers of the circuit board and through holes formed therein.

Abstract: An electric power steering apparatus includes a worm interlockedly connected to an output shaft of an electric motor, a first and a second bearing each supporting the respective side of the worm in a housing, and a gear wheel meshed with the worm. The housing includes a fitting bore in which the first bearing supporting a side of the worm closer to the electric motor is to be fitted, and an annular retaining portion located at a position corresponding to the second bearing and eccentrically oriented with respect to the center (axial center) of the fitting bore in a direction that shortens a distance L between the center of rotation of the worm and that of the gear wheel, and the annular retaining portion retains a coil spring around an outer circumference of the second bearing.

Abstract: A vehicle steering control apparatus has a steering wheel, a steering mechanism mechanically separate from the steering wheel for steering the left and right front wheels and a reaction force motor for imparting an operation reaction force against the steering wheel. A steering motor is provided to impart a turning force to the steering mechanism, while a clutch is provided to mechanically connect and disconnect the steering wheel to and from the steering mechanism. A drive torque detector is provided to detect a drive torque imparted to the steering reaction force actuator. A torque sensor is provided to detect an operating torque imparted to the steering wheel. A clutch connection determiner determines that the clutch is in a connected state when a drive torque direction detected by the drive torque detector and an operating torque direction detected by the operating torque detector are different.

Abstract: An electric power steering system is provided which is capable of providing a favorable steering feeling without using compensation logics such as of inertia compensation and friction compensation. The electric power steering system includes road-noise suppression control means (213) for controlling a steering assist motor (9) in a manner to damp torque transmission in a higher frequency region representing road noises than a frequency region representing road information. A friction value of a steering mechanism (A) is decreased enough to allow the intrinsic vibrations of the steering mechanism (A) to appear. Rotor inertia of the steering assist motor (9) is set to a value small enough to allow the frequencies of the intrinsic vibrations to be present in the frequency region where the torque transmission is damped by the road-noise suppression control means (213).

Abstract: A seismic signal generating system comprises a hammer positionable to impact a baseplate assembly. An actuator acts cooperatively with the hammer to urge the hammer to impact the baseplate assembly. A friction brake is actuated to impart a friction force to the hammer. The friction force restrains motion of the hammer until the brake is released. A method of generating a seismic signal comprises coupling a hammer to an actuator. The hammer is restrained from motion using a friction brake. The friction brake is released such that the actuator urges the hammer into contact with a baseplate assembly generating a seismic signal.

Abstract: An active muffler (1) for an exhaust system (2) of an internal combustion engine has a first space (3) and a second space (4) that is separated from the former via a partition (5). The partition (5) has a wall opening (6) into which is inserted an electronic sound absorber (7) having a chassis (8) and a diaphragm (9). During operation, the electronic sound absorber directs anti-sound toward the first space (3) and thereby reduces the sound emission generated by the exhaust system (2). The chassis (8) of the electronic sound absorber (7) and the partition (5) are made in one piece.

Abstract: A silencer having improved noise reduction characteristics is disclosed. The silencer includes a first cylindrical connection pipe for guiding the flow of a fluid, a cylindrical expansion pipe communicating with the first connection pipe at one end thereof for guiding the flow of the fluid, the expansion pipe having a sectional area greater than that of the first connection pipe, and a second cylindrical connection pipe communicating with the other end of the expansion pipe for guiding the flow of the fluid. The expansion pipe has a length (L) decided depending upon a diameter (D) of the first connection pipe or the second connection pipe. According to the present invention, resonance caused by a pipe connected to the silencer is prevented, and therefore, the noise reduction efficiency of the silencer is improved.

Abstract: The present invention relates to a muffler for an exhaust system of an internal combustion engine, including a housing having at least one absorption chamber which is filled with an absorbent material that has an absorbent effect for airborne sound, a straight-through pipe that carries exhaust gas during operation of the muffler and passes through the housing, and at least one blind pipe that is connected at one end laterally to the straight-through pipe and is sealed at the other end. The blind pipe has a wall that is acoustically transmissive for airborne sound in an area running in the absorption chamber.

Abstract: The improved muffler design has a housing that is hexagonal in shape that is formed from an upper plate, a lower plate and sidewalls that form a perimeter around the housing. An inlet and outlet are attached to opposite sides of the housing along the length. A primary vein is mounted within the housing with that allows some of the gases to around the vein and some of the gases to flow through holes in the leading surface of the primary vein. A secondary vein is mounted downstream of the primary vein and a mixing vein is mounted downstream of the secondary vein. The widest point more of the housing is closer to the than the outlet so the housing resembles a coffin.

Abstract: A mobile mount for attachment of a fall arrest system is provided for example for aircraft and includes a base carried on ground wheels and a support which is adjustable in height upstanding from the base and an arm cantilevered over the base. At least one receptacle is mounted on the arm of the support at a position located over the base for attachment to a personal fall arrest system including a harness for one or more persons, with the receptacle, base and support being designed and arranged to receive a loading from the personal fall arrest system sufficient to accommodate a fall of the person from the elevated structure.

Abstract: A simple, economical, and highly effective auto locking belay device is presented, certain embodiments of which contain no moving parts. The simplicity of the device is due to the fact that it derives certain functionality from its attachment carabiner that would normally be found within an auto-locking belay device itself. In its simplest form, the Device (10) comprises only a Body (14) with an Inner Channel (16) and a Pin (12_). The attachment carabiner supports the path of the rope through the device, constrains an axis of rotation around which the device rotates, and provides one of two surfaces between which the rope is pinched. The device is able to extract these functions from the carabiner due to a unique, and counter-intuitive, placement of the carabiner within the same geometric plane as the path of the rope through the device.

Abstract: Disclosed is a scaffold installed within a large structure such as a pressure vessel or a tank of a ship, and an insulation system construction method using the same. The scaffold for use in performing desired work within a large structure includes a supporting structure installed adjacent to both side surfaces and a top surface of the large structure, and a carrying unit installed movable along the supporting structure to allow materials to be carried or to provide a working space for a worker thereon, wherein the supporting structure is installed to be movable along a wall surface of the large structure.

Abstract: Disclosed is a scaffold installed within a large structure such as a pressure vessel or a tank of a ship, and an insulation system construction method using the same. The scaffold for use in performing desired work within a large structure includes a supporting structure installed adjacent to both side surfaces and a top surface of the large structure, and a carrying unit installed movable along the supporting structure to allow materials to be carried or to provide a working space for a worker thereon, wherein the supporting structure is installed to be movable along a wall surface of the large structure.

Abstract: Disclosed is a scaffold installed within a large structure such as a pressure vessel or a tank of a ship, and an insulation system construction method using the same. The scaffold for use in performing desired work within a large structure includes a supporting structure installed adjacent to both side surfaces and a top surface of the large structure, and a carrying unit installed movable along the supporting structure to allow materials to be carried or to provide a working space for a worker thereon, wherein the supporting structure is installed to be movable along a wall surface of the large structure.

Abstract: A ladder attachment device having at least a substantially rigid and substantially planar first member which is connectable at or adjacent a first end to a substantially flat portion of a rung or a top member of a ladder. A substantially rigid and elongate second member pivotally is connected at or adjacent a second end of the first member. The device can be clamped to the rung or top member of a ladder to provide a storage area for tools or materials, and the elongate member provides additional support for the ladder. The first member sets the ladder back from a wall or structure meaning that a person working on the ladder tends to lean into the ladder when working, rather than leaning back which can cause a ladder to topple.

Abstract: A method and system for fabricating molded composite support members for use in climbing structures, which molded composite support members comprise variable performance properties along a longitudinal length thereof. The variable performance properties are achieved or provided by selectively reinforcing one or more regions determined to be subject to greater stress, thus allowing a minimum amount of material to be used in other areas that will subject to less structural stress. Selective reinforcement is accomplished by adapting one or more regions of a primary composite material composition with a supplemental composite material composition, wherein the supplemental composite material composition increases the amount of composite material fibers within that particular region.

Abstract: A kneeling device comprising a platform produced from a resilient material, and handles capable of releasably interlocking with the ends of the platform, the platform further having two depressions formed therein for receiving knee pads for accommodating the knees of an individual.

Abstract: According to certain aspects of the invention, a trailerable miniature forklift is disclosed for moving portable toilet enclosures. The forklift may include a chassis including a frame, a power source, a control interface, and a plurality of wheels, the chassis sized and configured to permit walk-behind operation of the forklift. The forklift may also include a movable lift arm attached to the chassis configured for selectively lifting or placing a portable toilet enclosure of a given size, the control interface allowing a user to manipulate the power source to drive the forklift chassis via the wheels and to selectively position the movable lift arm relative to the frame. The forklift frame and wheels may be sized and configured so as to define an external perimeter no larger than a portable toilet enclosure of the given size, and the forklift may be sized and configured so as to have a weight that is no more than about four, or three, times the weight of the portable toilet enclosure of the given size.

Abstract: A materials handling vehicle is provided comprising a power unit, a mast assembly and a fluid supply system. The mast assembly is coupled to the power unit. The mast assembly comprises a weldment, a movable element and a ram/cylinder assembly coupled to the movable element to effect movement of the element. The fluid supply system includes manifold apparatus and at least one fluid line coupled to the manifold apparatus and the ram/cylinder assembly. The manifold apparatus provides pressurized hydraulic fluid to the ram/cylinder assembly via the fluid line to raise the movable element. The manifold apparatus is mounted to the mast assembly.

Abstract: The invention relates to an elevator installation and a method for mounting a drive unit of an elevator installation. The elevator installation comprises a car and a counterweight in a shaft and a drive unit mounted on a crossbeam or the shaft roof. The drive unit has two spaced-apart drive zones. The drive zones are in that case integrally integrated in the drive shaft and directly machined therein.

Abstract: An elevator system comprises a hoistway; an elevator car (12) arranged to move vertically within the hoistway; a plurality of landings opening into said hoistway; and a pit (22) located below a lowermost landing (18). The elevator system further comprises an engineer interface, e.g. a key switch, located at or near the lowermost landing arranged to generate a control signal for moving the elevator car to a predetermined parking position above the lowermost landing thereby allowing access to the pit.

Abstract: The invention is relating to a coupling device for elevator car (5) and landing doors of the kind comprising moving cams (3) integral with the car door (5) and driving the landing door in front of a story landing by means of a coupling plate integral therewith and engaging with the cams (3), locking it mechanically and electrically upon door closure to allow the subsequent drive of the car, wherein said cams (3) are movably mounted with a variable distance from each other on the car door (5), independently from the car door drive belt (19), and a part (7) is provided to drive the cams (3) with a variable distance, which part (7) is mounted on the car door (5) and connected to the drive belt (19) and to one of the cams (3) to drive it towards and away from the other cam (3) with a large displacement relative to a small overtravel drive of the belt (19), in order to respectively allow to unlock the coupling plate and its landing door drive coupling when the doors open and to lock it when they close.

Abstract: A brake stroke indicator, comprising a L shaped indicator member disposed on the push rod clevis pin, and a concealing means. The indicator member comprises a first section with holes to connect with the push rod clevis pin and slack adjuster, and a second section of highly reflective color surface angularly disposed to the first section. The indicator member moves with the clevis pin, and oscillates as the push rod is reciprocating. The indicator member hides behind the concealing member while the push rod reciprocates within safe limits. The second section of indicator show up out of the concealing means when the push rod goes beyond its safe operational limits.

Abstract: A pad clip is made by an elastic plate and includes a base plate portion, and a pair of elastic plate portions folded to bend in the same direction from both end portions of the base plate portion. The pad clip is provided with an elastic force in a direction of expanding an interval between the two elastic plate portions. In a state of elastically contracting the interval between the two elastic plate portions, the pad clips are inserted to inner sides of guide recessed portions formed at a pressure plate constituting the brake pad, thereby, the two elastic plate portions are elastically pressed to inner faces of the two guide recessed portions to thereby mount the pad clip to the pressure plate.

Abstract: An axle shaft includes an electromechanically or pneumatically actuated disc brake, especially for a useful vehicle. The brake disc and the caliper can be displaced in relation to each other, and the caliper is fixed to the axle shaft on at least two fixing plates extending preferably from the axle shaft in different directions, at at least respectively one fixing point. The axle shaft is characterized by the arrangement, especially the orientation and/or embodiment, of the fixing plates, and the fixing points of the caliper or of an optional brake carrier on the fixing plates, which is selected in such a way that there is either no displacement of the fixing points on the fixing plates or a parallel displacement of the fixing points on both fixing plates perpendicularly to the brake disc.

Abstract: The invention relates to a rapid recovery shock absorber system with hydraulic end stop, comprising a stem (3) and a body (1), in which a piston (8, 9, 10, 11) runs which is fixed to a tube (71) and which defines at least one upper chamber (S) and one lower chamber (I) in the body (1). A body (32, 32a) in the stem (3) comprises a housing (321), in which a piston (33, 33a) runs which is connected to a rod (7) which slides in the tube (71). A clamp (31), for fixing the shock absorber system to the vehicle, tensioning means (35, 37, 39), exerting a force which tends to displace the piston (33, 33a), sliding in the stem body (32, 32a), driving the displacement of the rod (7) which results in the opening or closing of a section of an oil passage in the lower chamber (I) towards the upper chamber (S) are also provided.

Abstract: A shock absorber is attached coaxially with a reciprocating rod driven by a reciprocating unit to prevent a bending moment from being applied to the reciprocating rod in absorbing an impact force. The shock absorber has a hollow rod and an outer cylindrical body mounted axially movably relatively to and outside the hollow rod. An accommodating space is formed between the hollow rod and the outer cylindrical body. A spring force in a direction of being relatively directed to one end portion side of the hollow rod is applied by a compression spring to the outer cylindrical body. The hollow rod is provided with an annular piston which partitions the accommodating space into two liquid chambers. When an impact force in a direction of being relatively directed to the other end side of the hollow rod is applied to the outer cylindrical body, liquid flows from one of the liquid chambers to the other through a gap, so that a resistance force is applied to the annular piston.

Abstract: A shock absorber is attached coaxially with a reciprocating rod driven by a reciprocating unit to prevent a bending moment from being applied to the reciprocating rod in absorbing an impact force. The shock absorber has a hollow rod provided with a through hole and an outer cylindrical body mounted outside the hollow rod so as to be movable axially relatively and attached to the reciprocating unit. An accommodating space is formed between the hollow rod and the outer cylindrical body. A spring force in a direction of being relatively directed to one end portion side of the hollow rod is applied to the outer cylindrical body by a compression coil spring. An annular piston for partitioning an accommodating space into two liquid chambers is provided in the hollow rod. When the impact force is applied to the hollow rod so as to be slid to the hollow rod, the liquid flows from one liquid chamber to another liquid chamber through a gap, whereby a resistance force is applied to the annular piston.

Abstract: This invention relates to a collision impact energy absorber that offers to absorb shock, impact and subsequent damage to vehicles in motion and other moving objects that require safety from impacts. This device fitted at appropriate impact zones of vehicles and crafts that move on and over land, air and water is capable of absorbing impacts of very high order and enhances the safety of lives and property. These can act in single units or in clusters where impacts of very high order are anticipated. The impact energy is directed into the hollow housing unit by a ram shaft that dislocates a series of vertically positioned sectional plates placed at intervals thereby absorbing the energy of the impacts on the host vehicle. This device is fitted as multimodular mode in tandem and also as multiple integrated modules to enhance its load dissipation efficiency.

Abstract: A hydrodynamic clutch includes a housing which can be brought into working connection with a drive; a hydrodynamic circuit formed by a pump wheel and a turbine wheel; a torsional vibration damper having a drive side transmission element, a takeoff side transmission element, and at least one energy storage group between the transmission elements; and a bridging clutch including first friction elements connected to the housing and second friction elements connected to the drive side transmission element. A first flow route extends from a first flow passage to the friction elements, and a second flow route extends from the hydrodynamic circuit to a second flow passage. A sealing arrangement cooperates with the drive side transmission element to separate the first flow route from the second flow route.

Abstract: The invention relates to a coupling device for establishing a couplable connection between two rotationally mounted machine parts, particularly a first shaft and a second shaft. To this end, the second shaft comprises a coupling ring that, on the inside, has tensioning bodies, which act against each another in pairs and which are arranged so they surround the shaft.

Abstract: One-way clutches primarily employ a driving ring, a driven ring, and a number of identical connectors. The driving ring and the driven ring are rotationally detached, are concentric, and are configured to house the connectors between them. In one rotational direction, the connectors engage the driving and the driven rings, causing them to rotate in unison. In the opposite rotational direction, the connectors disengage the driving and the driven rings, causing them to freewheel. All existing one-way clutches are aided by means that bias the connectors toward engagement, introducing noise, wear, and heat while freewheeling. Additionally, existing one-way clutches that utilize relatively more efficient pawls as connectors, undergo relatively more backlash from freewheeling to engagement, introducing operational imprecision. The one-way clutch in the present invention utilizes pawls for maximum mechanical efficiency.

Abstract: A clutch assembly and damper arrangement is provided that includes a driver hub and a driven element coupled to the driver hub by a compliance element. A clutch is provided that is selectively engageable to the driven element. The clutch has a housing supporting the compliance element and is torsionally unitary with the driven element.

Abstract: A viscous fan drive in which the output drive to the fan is controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. The input-coupling assembly and cover member are formed with a unique combination of continuous and non-continuous radially extending lands and grooves designed to distribute the viscous fluid in a continuous film throughout the shear zone so as to maximize output fan speed at a given input speed. An armature-venting feature is designed to simplify the opening and closing of the valve disk in an electronic version of the viscous fan drive depending upon the desired operating condition.

Abstract: The invention relates to a system for the hydraulic control (10) of a clutch (12), e.g. a motor vehicle clutch, comprising an upstream master cylinder (14) which is connected to a down-stream slave cylinder (18) by means of a conduit (16). The invention is characterized in that the system comprises a servo cylinder (30) which is disposed in the conduit (16) between the master cylinder (14) and the slave cylinder (18), said servo cylinder comprising at least one servo piston which can be subjected to an assist force produced by a servo device.