Abstract: Apparatus for screw transmission on a spindle comprising a nut having at least a first and second part with internal threads, at least one bore in the first and second parts, and at least one spring located within the at least one bore of the first and second parts and arranged with a bending load acting crosswise to a longitudinal direction of the bore. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A motor vehicle includes a drive train having a drive unit, a gearbox having a first gearbox input shaft and a second gearbox input shaft, and a clutch having a first clutch device which is associated with the first gearbox input shaft, and a second clutch device which is associated with the second gearbox input shaft, for transferring torque between the drive unit and the gearbox. The first and second clutch devices are plate clutches to which an operating fluid, such as a cooling oil, is supplied to operate the same. The gearbox is associated with an actuator device and a control device for controlling the actuator device, the arrangement of which enables the gears associated with the first and second gearbox input shafts to be engaged and disengaged. The control device is designed such that at least one gear is automatically engaged by the actuator device, as a result of the clutch release of the vehicle.

Abstract: A shifter rod assembly used in automotive vehicles extends between a manual shifter assembly having a manual shift lever and a transmission spaced from the manual shift lever. Large tolerance universal joints with play between the components thereof connect the shifter rod assembly to the manual shifter assembly and to the transmission. In order to eliminate rattle noise in the universal joints, the universal joints are each encased in a layer of elastomer. A preferred elastomer is silicone elastomer can be applied in liquid form, cures at room temperature and maintains integrity at temperatures in a range of about 200° F. to 240° F.

Abstract: A rotatable selector mechanism for a motor vehicle transmission has a selector knob rotatable in a housing to select an operating mode of the transmission among a number of selector positions indicated by a label (P,R,N,D,M). The selector mechanism further includes a detent plate which cooperates with a detent pin for maintaining the selector knob in each of positions. The detent plate is connected to position sensors for generating selector signals to a transmission control unit which supplies control signals to an actuator for operate the transmission according to the operating mode selected. The detent plate is also associated to the selector knob and to a drive correction means by means of clutch devices respectively to engage the detent plate to one of the selector knob and the drive correction means.

Abstract: An apparatus (40) for transmitting force between a steering wheel (28) and a steering gear (26) that is operable to turn steerable wheels (14) of a vehicle (10). The apparatus (40) includes a shaft assembly (42) including a pair of telescoping shaft portions (52, 54) rotatable about a common axis (56) to effect vehicle steering. A bearing (60) that supports at least one of the shaft portions (52, 54) for rotation about the common axis (56). A support (244) for the bearing (260) is breakable when the shaft portions (52, 54) are blocked from telescoping movement. A containment structure (280) permits limited movement of the shaft portions (52, 54) transverse to the common axis (56) in the event that the support (244) breaks.

Abstract: An adjustable pedal assembly includes a screw (62) for moving a pedal (16) along a rod (22) between a plurality of adjusted positions. A conduit (53) rotatably supports a core element (55) that is rotated by an electrical motor (52). A pair of female (56) and male (57) connectors attach the conduit (53) in an operative position on a gearbox (20) with the core element (55) connected to a worm (58) engaging a worm gear (60) to rotate the screw (62). Any such adjustable pedal assembly may be characterized by a pair of electrical contacts (70) and (72) supported by the respective connectors (56) and (57) for electrical contact to transmit electrical current through the electrical leads (74) and (76) when the connectors (56) and (57) are connected together but for discontinuing electrical conductivity when the connectors (56) and (57) are separated. The drive motor (52) is operative only when the connectors (56) and (57) snugly interconnected.

Abstract: A transmission fluid sump for an automotive transmission comprising a reservoir portion, a threaded extension on the reservoir portion and a fill pipe threadably connected to the extension. A closure member seals a central opening in the extension independently of the fill pipe, thereby avoiding overlapping torque windows for the fill pipe and the closure member while providing a single leak flow path for the transmission fluid.

Abstract: A support structure for a rotor within a transmission system is provided. The cantilevered support structure is umbrella-shaped to create an area of space between the rotor and the main shaft where other vehicle components, such as a gear set or system of clutches, may be packaged. The cantilevered support structure may be a true cantilever or a steady-rested cantilever. The support structure maintains the rotor at a distance from the transmission main shaft to maintain torque within the system while compacting packaging requirements. A second cantilevered support structure is wineglass-shaped to create a second area of packaging space between the rotor and the main shaft. The support structures may be telescoped to further compact the transmission.

Abstract: A rotating regulating device for the rotation and/or linear displacement of an actuating element of a valve, throttle, blowout preventer or similar, in particular in the field of gas or oil supply, exhibits a spindle drive and a drive train rotationally driving the spindle drive, the said drive train exhibiting at least one reduction gear unit and a drive device connected to it for movement.

Abstract: A diaphragm of a cup-shaped flexible external gear of a cup-shaped wave gear device having a high reduction ratio of 100 or higher is given a thickness t in a position of a radius r of the diaphragm whereby the thickness t is a value that satisfies the expression A/r2 when A is a constant. The constant A is preferably a value that satisfies the expression 0.0014D3<A<0.0026D3, where D is a pitch diameter of the flexible external gear, and the range of the radius r whereby the thickness t is defined as described above in the diaphragm is preferably set to satisfy the expression 0.6d<r<0.4D, where d is a diameter of a discoid rigid boss made continuous with an internal peripheral end of the diaphragm. Stress concentration can be alleviated, and it is possible for the allowable transmission torque to be increased compared to the prior art.

Abstract: The invention relates to the use of a hard metal alloy for parts, which are subject particularly to torsion in addition to wear. Said hard metal alloy substantially contains tungsten carbide having an average grain size of less than 1.2 ?m and 13 to 23 percent by weight of binder metal which comprises one or several metals that is/are selected among the group consisting of cobalt, iron, and nickel.

Abstract: Nanoparticles of intermetallic alloys such as FeAl, Fe3Al, NiAl, TiAl and FeCoV exhibit a wide variety of interesting structural, magnetic, catalytic, resistive and electronic, and bar coding applications. The nanosized powders can be used to make structural parts having enhanced mechanical properties, magnetic parts having enhanced magnetic saturation, catalyst materials having enhanced catalytic activity, thick film circuit elements having enhanced resolution, and screen printed images such as magnetic bar codes having enhanced magnetic properties. In contrast to bulk FeAl materials which are nonmagnetic at room temperature, the FeAl nanoparticles exhibit magnetic properties at room temperature.

Abstract: Molding compositions and forming processes for normally rust-prone iron-based powders, and articles produced therefrom. Metal alloy systems that can be successfully formed using the processes of the invention, include elemental iron and iron alloys including low and medium alloy steels, tool steels and a number of specialty iron-base alloys.

Abstract: The invention relates to monodispersable, optionally magnetic particles containing one or more metals, optionally, protected by a secondary treatment with air, having an adjustable average particle size of between 2 and 15 nm and a narrow distribution of particle size with a standard variance of 1.6 nm at the most. The invention also relates to a method for the production of said materials. Said materials are used in an isolated form or dispersed in a solution inter alia as a sealing medium against dust and gas in magnetic fluid sealing systems (liquid O-ring) for the lubrication and bearing of rotating shafts (magnetic levitation bearings), for the magneto-optical storage of information and additionally, for the magnetic marking of cells and the separation thereof in biological samples or for the local application of medicaments.

Abstract: The invention relates to a method for treating slag created in the production of blister copper processed directly from concentrate in a suspension smelting furnace, such as a flash smelting furnace, in order to recover the copper, so that at least part of the slag is leached in at least one step.

Abstract: A process for producing iron metal and slag by smelting iron-containing source material, having iron present as oxide and/or a partially metallised state, in a reactor containing a molten bath comprising or having a slag phase, utilises injection of fuel/reductant and oxygen-containing gas into the slag, by at least one top-submerged lance, to generate heating and reducing conditions in at least one reducing region in the bath. The source material is fed to the reactor, together with additional reductant and with flux, at or adjacent to the at least one reducing region, to subject the source material to smelting reduction which generates combustion gases comprising CO and H2. The rates of injection of the oxygen-containing gas and fuel/reductant by said at least one lance are controlled to achieve required, sufficient reducing conditions; and, in the reactor above the bath, the combustion gases generated by the smelting are post-combusted.

Abstract: A method of vacuum and pollution-free arsenic extraction, wherein increase the temperature of smelting chamber to 100-300° C. and then hold the temperature to remove the vapor and small quantity of dust in the arsenic concentrate; Under residual pressure50 Pa, increase the temperature of smelting chamber and crystallization chamber to 300-500° C. and then hold the temperature to remove the volatilized arsenic sulfides; Hold the temperature of crystallization chamber, increase the temperature of smelting chamber to 500-600° C. and then hold the temperature to remove the gaseous element sulfur decomposed; Increase the temperature of smelting chamber to 600-760° C. and then hold the temperature, lower the crystallization chamber temperature to 270-370° C. and then hold the temperature to get element arsenic; shutdown, lower the temperature, charge the air, stripe arsenic product and conduct deslagging, and extract fine gold using conventional method.

Abstract: Process for extracting and recovering metals, including precious metals, such as platinum group metals and gold, from natural ores, ore concentrates or industrial materials, including contacting the natural ores, ore concentrates or industrial materials with a hydroxide-containing compound at an elevated temperature; dissolving the material in a solution, and recovering the metals from the solution.

Abstract: A hammer includes a handle, a head mounted on the handle and having a distal end having an end face formed with an insertion recess, and a striking portion mounted on the distal end of the head and having an end face formed with an insertion block inserted into the insertion recess of the head. Thus, the cushioning gap between the striking portion and the head provides a vibration absorbing and cushioning effect during operation of the hammer, so that the hammer is operated smoothly and stably, thereby enhancing the striking effect of the hammer, and thereby facilitating a user operating the hammer.

Abstract: A bit for removing a broken fastener comprises a tip from which extend two or more notches separated by scraping surfaces formed from two-sided frusto-conically-shaped regions. The scraping surfaces are bounded on one side by a cutting edge and on the other side by a non-cutting edge and are configured to cut into the fastener when the bit is rotated in a direction opposite to the fastener's direction of engagement. Specific embodiments include configurations where the cutting edges extend at different angles with respect to the bit axis and where the scraping surfaces comprise a plurality of serrations.

Abstract: This invention relates to a method for economically and efficiently producing cores for use in the production of an image cylinder or a blanket cylinder for use in an electrophotographic process.

Abstract: The disclosed embodiments are directed to an improved automatic screw machine employing a first servomotor connected to cause rotation of a first set of tooling cams independently of the operation of a spindle drive, and a second servomotor to cause rotation of a second set of cams independently of the operation of the spindle drive, wherein a multi-axis controller controls at least the speed of the spindle drive in conjunction with at least each of the two servomotors, and where the operation of at least the two servomotors is electronically synchronized.

Abstract: An apparatus for sensing a position of a cutting tool in a computer numerical controlled machine tool is provided including an arm supporting and moving a sensor that cooperates with the cutting tool. Also provided is a housing including a gear assembly and a driving motor for moving the arm, and a stopper for defining an operating position of the arm. The driving motor supplies rotation force to the gear assembly so as to pivot the arm against the stopper and then apply force to an elastic member. When the driving motor is stopped, the elastic member applies a force, through the gear assembly, urging the arm against the stopper in the operating position.

Abstract: A system and method for sealing a live center is provided. The live center has a spindle disposed, at least in part, within a housing, bearings provide a rolling connection between the spindle and the housing, and a labyrinth seal is mounted to at least one of the spindle and the housing and is configured to reduce an amount of contaminant from entering the housing. A method of sealing a live center is also provided. In some embodiments of the invention, the method includes restricting a fluid path along a spindle, defining the fluid path to have a labyrinth section, providing a drain to the outside of the live center for fluid moving along the path and substantially blocking the path of the resilient seal.

Abstract: A laser marker 28 includes fixed legs 64 and 66, and a retractable leg 76, extending therefrom. With legs 64, 66 and 76 extended, the laser marker 28 can be moved about a workpiece surface 124 to selectively locate the line mark 137. With the leg 76 retracted, the legs 64 and 66 can be moved along, a workpiece edge surface 140 to selectively locate the line mark 137. The laser marker 28 can be positioned precisely on a circular saw shoe 150 by placing the legs 64 and 66 within reference holes 180 and 182 on a platform 164 on the shoe. The laser marker 28 can be positioned precisely on a protractor platform 244 by locating the legs 64 and 66 in a first circular guide track and the leg 76 in a second circular guide track 111.

Abstract: An apparatus (10) and method for crosscutting a web (12) of material has employs a knife (24) that is angled relative to the surface of the web. Orienting the knife so that an upper portion of the cutting edge engages the web after a lower portion of the cutting edge engages the web facilitates cutting the web at a transverse cut angle (?) of about 20 degrees. Simultaneously orienting the knife so that the upper portion of the cutting edge engages the web at a different position along the side edge than the lower portion of the cutting edge facilitates cutting the web at a horizontal cant angle (?) in the range of about 10 degrees to about 50 degrees.

Abstract: A multi-blade adaptor is comprised of a drive bushing that is inserted into a circular saw and of a cap or blade clamp that fits onto the drive bushing, sandwiching the blades between the two.

Abstract: Disclosed is a blade tension gauge for a band saw which provides a constant reading of the magnitude of the forces that act to put tension on the blade. The band saw includes a moveable wheel, a blade, and a frame, where movement of the moveable wheel in relation to the frame tensions the blade. The blade tension gauge includes a wheel positioning assembly rigidly connected to the moveable wheel and connected to the frame to be moveable relative to the frame. A load element is positioned to receive a load existing between the wheel positioning assembly and the frame. A sensor is configured to measure the load. A display is configured to display the tension value. Also disclosed is a method for outputting the tension of the blade of a band saw.

Abstract: The present invention provides a horizontal paper cutter that includes a pair of movable arms, each of which has a spindle attached thereto. The spindles are generally aligned with each other, and are configured to engage respective ends of a horizontally oriented paper roll. A pair of actuators are used to move the arms upward, thereby lifting the paper roll off the floor. One of the spindles is operable to rotate the paper roll after the paper roll is lifted off the floor. A saw that is initially above the paper roll is moved downward into the paper to effect removal of a damaged end of the roll.

Abstract: An apparatus for sawing a workpiece on predetermined cutting lines while the workpiece is being continuously transported in a downstream direction includes first and second conveyors having a spaced array of workpiece elevating supports mounted on at least the second conveyor translating for the workpiece in the downstream direction, at least one saw mounted on corresponding saw transports adjacent the second conveyor, a workpiece scanner and a data processor and controller for processing the data received from the scanner; determining the position of the cut lines; for controlling the relative phase positions of the first and second conveyors such that the cut lines do not coincide with the position of the workpiece elevating supports; and for actuating downstream translation of the saw on the saw transport so as to align the saw with the cut lines as the workpiece and the saw are translated downstream in unison while the saw cuts the through workpiece at the cut lines without contacting the underlying conve

Abstract: A circular saw for sawing wood pieces, which circular saw has blade guides (5, 21) which are fastened to fastening arms (4, 22), and in which the fastening arm (4, 22) of the blade guides (5, 21) is fastened concentrically with a drive axle (6, 23) of the saw blade (1) pivotedly so that the fastening arm is able to turn around the drive axle (6, 23), and the blade guides are fastened to the fastening arm (4, 22) pivotedly with a fastening bearing (10, 24) so that they are able to turn around the fastening bearing (10, 24).

Abstract: A rotary cutting apparatus includes a rotary cutter and a cooperating anvil roll, each including a center arbour, a peripheral sleeve, and an intermediate sleeve disposed radially between the peripheral sleeve and the arbour. The intermediate sleeve of either the rotary cutter on the anvil roll, or both can be formed of a material for vibration damping, thermal insulation, thermal conduction, weight increase and/or weight reduction.

Abstract: A sawdust collection system includes a sawdust duct secured in a saw blade housing and having an enlarged portion formed on a front end thereof. A sawdust chute is partially pivotally received in a lower portion of the enlarged portion of the sawdust duct such that the sawdust chute can be swung relative to the sawdust duct. A first stopper laterally outwardly extends from a bottom of the sawdust chute and a torsion spring is mounted between the sawdust duct and the sawdust chute to prevent the sawdust chute from a vibration during operating. A second stopper laterally outwardly extends from a top of the sawdust chute. The second stopper selectively abuts a distal edge of the enlarged portion for limiting the moving range of the sawdust duct.

Abstract: A microtome comprising a knife holding device for a cutting element (16) and comprising a specimen holding device (12) for a specimen which is to be cut thin is described. Associated with the specimen holding device (12) for performing a cutting movement is a first drive device (18) and associated with the specimen holding device (12) or the knife holding device is a second drive device (38) for performing a feed movement. A sender (20) is associated with the first drive device (18). The sender (20) is connected with an electronic control means (28). Control of the first drive device (18) is effected by means of a first operating element (28). Control of the second drive device (38) is effected by means of a second operating element (44). To achieve an excellent degree of operating comfort for the microtome the first operating element (28) has two control modes, namely a standard mode and a second mode.

Abstract: Disclosed here in the present utility model is a pattern cutter. The pattern cutter includes a base and blade. The blade is located on the base. The blade forms the shape of pattern to be cut. The said base and blade are of one-piece structure, which is machined to shape at one go through die-casting process. The height of the said blade is greater than or equal to 2.5 mm on the base. The angle of the cutting edge of blade is smaller than or equal to 60°. The said blade is surfaced with a plating coat. The present utility model is characterized by simple and rational construction, easy to make, low cost, high product accuracy and good consistency, with a wide range of adaptability and better market prospect.

Abstract: A circular gang edger blade comprises a plurality of teeth having a cutting angle and being arranged on the periphery of the blade so as to yield a pitch between two adjacent of the teeth between about 2.3 cm and about 3.2 cm; each pair of adjacent teeth defining a rounded gullet therebetween for receiving and removing sawdust. The teeth are configured and sized so that each gullet defines a sawdust-receiving area comprised between about 1.1 cm2 and about 1.7 cm2. Some of the gullets are provided with a recess defining an expansion joint extending in a direction defining a smaller angle than the cutting angle. Contrarily to gang edger blades from the prior art which are characterized by a sawing variation of at least 0.635 cm, it has been observed that a gang edger blade according to the present invention is characterized by sawing variation of no more than 0.25 cm.

Abstract: An electric music apparatus comprises an interface for connecting an external device, a memory that stores device drivers for external devices connected to the interface and a list recording relationships between external devices and corresponding device drivers, an obtaining device that obtains an external device information from an connected external device, a searching device that searches a device driver corresponding to the connected external device with reference to the list in accordance with the obtained external device information; a first determining device that determines the device driver corresponding to the connected external device when the searching device detects the corresponding device driver from the list, and a second determining device that executes a specific command to the connected external device by using a device driver stored in the memory when the searching device cannot detect the corresponding device driver and determines a driver without an error as a corresponding driver.

Abstract: A slide rule for music includes a first element that includes a first set of indicia representing in linear form the structures of a plurality of musical scales, chords and/or modes, and a second element that includes a second set of indicia representing the names of the notes of a chromatic scale. The second element is constructed and arranged for movement relative to the first element in two orthogonal directions, so as to indicate the relationship between the notes of the chromatic scale and the structure of a selected one of the musical scales, chords, and/or modes.

Abstract: An automatic tuning system for a stringed instrument is provided having a string adjustment assembly comprising a motor and gear assembly, wherein the motor and gear assembly is pivotable on a housing for the tuning system. The system can also include a vibrato arm in contact with the motor and gear assembly, and a vibrato return spring in contact with both the motor and gear assembly and the instrument, which is capable of reversibly changing the position of a string contact surface in the string adjustment assembly with respect to the string, thereby lowering the pitch of the string and then raising it to its original pitch. The system can also include an option board for wireless communication with remote components such as a remote footswitch or other type of control panel. Other remote devices may also be wirelessly connected to the tuning system, including other instruments, audio devices for receiving sound, and the like.

Abstract: A method of positioning a set of frets on a musical instrument. This method comprises dividing a fretboard of the musical instrument into a plurality of units, and then dividing these plurality of units into a series of groups. Next, these groups can be divided into sub-groups to form intervals. Next musical pitches or frets can be positioned for the musical instrument wherein these pitches are further sub-groups of the intervals of these units. In one embodiment, these units can be in the form of 360 equally divided units. In another embodiment, these units can be in the form of 648 units of 1 mm in length. A set of predetermined spacing relationships can then be used to create the spacing distances and the positions of the frets on a fretboard.

Abstract: A switching power circuit in which a synchronous rectification circuit of the winding voltage detection system by use of a resistance device is provided on the secondary side of a compound resonance type converter, whereby a high power conversion efficiency can be obtained, and a reduction in the circuit scale through circuit simplification can be had. The gap length of an insulated converter transformer is enlarged to set the coupling coefficient at about 0.8, and the numbers of turns of the primary winding and the secondary windings are so set that the induced voltage level in the secondary winding is not more than 2 V/T. This causes the secondary-side rectified current to be in a continuous mode even under a heavy load condition by setting the magnetic flux density of the core in the insulated converted transformer to be not more than a predetermined value.

Abstract: A rapid mine removing system comprises a remote controlled air-means (A) provided with mine—(M), in particular anti-personnel mine-surveying and controlling devices; an also remote controlled terrestrial means (T) provided with mechanical means suited to pick up from the ground the booby traps as located by the air-means (A) for their subsequent blasting through skilled personnel or concurrent hydromechanical neutralization; as well as a terrestrial means (C) with manned crew working at a safety distance according to the data automatically given by the remote controlled means (A, T).

Abstract: A ballistic resistant armor plate. The plate is a stack of laminae impregnated with an elastomer. Each lamina is a fabric of polyaramis impregnated with the elastomer. To prepare the armor plate, the stack of pre-impregnated laminae is cured, typically using heat and pressure. Typically, the elastomer does not react chemically with the but rather serves as a filler and binder.

Abstract: A readily replaceable bolt face for a firearm (10) with a movable slide (12) that strips a round from a magazine, extracts the spent round from the firing chamber and then ejects the round from the firearm by means of an ejector. A bolt face insert (32) has an external configuration that is common to a range of calibers, but with a bolt face side (66) designed to fit the rim of a specific caliber or calibers having the same rim dimension. The insert may be replaced to fit a different caliber without replacing the slide. The bolt face insert is provided with a slot (62) for the ejector and a groove (60) to accept an extractor for the specified caliber.

Abstract: The invention concerns a hydraulic machine, in particular a hydraulic motor, comprising: a body (1), a piston (9) adapted to slide in reciprocating motion in a cylindrical housing (7) of the body, a chamber (C1, C2) being formed on either side of the piston, hydraulic switching means for feeding and evacuating the respective chambers (C1, C2), control means (H) for abrupt change of the position of the switching means, and triggering means (13, 15) for, at the end of the stroke of the piston (9), changing the position of the switching means. The piston (9) is a single acting and non-differential piston, having a closed cross-section and the switching means are arranged in the body (1) of the machine, radially outside the cylindrical housing (7) wherein slides the piston (9).

Abstract: This invention improves response by preventing a steady-state difference and a disturbance from occurrence even when the volume of a pressure chamber of an air cylinder varies dramatically. In a method for controlling an air cylinder such that air is supplied to and exhausted from pressure chambers of the air cylinder by air servo valves; pressures in the pressure chambers are detected by pressure sensors; signals of the detected pressures are feedback to a controller; and the degrees of opening of the air servo valves are adjusted by corresponding PID adjusters of the controller on the basis of the respective differences between instruction values and detection values, the displacement of the rod of the air cylinder is detected by a displacement sensor, and a detection signal of the displacement is fed back to the controller so that a gain of the PID adjuster is always changed in accordance with the detection signal of the displacement.

Abstract: A positioning system includes an actuator, valve (preferably pneumatic), position sensor and an electronic valve controller, integrated in a single unit. Continuously variable setpoints are possible within the range of operation. A preferred control circuit includes a signal converter, a ramp generator to smooth the shape of the command or target value signal applied, a position feedback sensor to report the actual position of the actuator, a controller, and a driver, containing an H-bridge, for controlling the pneumatic valve which feeds air into the actuator mechanism. Integration of all these components into a single unit shortens signal paths, improves resistance to electrical noise, and permits faster response time.

Abstract: A pneumatic servomotor for an assisted braking including an emergency-braking assistance device to increase the assistance ratio when an input force is applied to the control rod that is higher than a predetermined value through an extrusion of the reaction disk. The device (D) has a plastically-deformable first member (68) and second member (74) to accurately set a jump height of the servomotor and the activation force.

Abstract: A vacuum booster which moderates a retraction speed of a valve seat member to restrain a contact noise between a key member retracting in a unitary manner with the valve seat member and a flange surface of a plunger. The vacuum booster includes a noise restriction device.

Abstract: The invention relates to a fluid circuit, in particular a hydraulic circuit for a load displacement device of an industrial truck, having a fluid supply line (118a, 118b, 118c), through which a fluid can be conveyed from a fluid tank (112) by means of a fluid pump (116) to at least one fluid store (120) of a consumer (122), and having a fluid return line (118c, 148, 118a), through which fluid can be returned, driven by the consumer, from the at least one fluid store (120) via the fluid pump (116) to the fluid tank (112), a valve (130) being provided in the fluid supply line (118a, 118b, 118c), which valve (130) allows fluid to pass through depending on the flow direction, allows a fluid supply flow (Z) to pass through from the fluid tank (112) to the fluid store and blocks a fluid return flow (R) from the fluid store (120) to the fluid tank (112), the fluid circuit also comprising at least one switchable valve (132, 134) which can be switched between a return flow passage position (140, 144?) in which it allo