A taper point surgical needle having improved needle point strength is disclosed. In one embodiment of the needle, a tip portion includes first and second integral tapered regions having first and second cross-sectional areas respectively which decrease progressively toward the tip of the needle in accordance with first and second angles of inclination respectively, with the first angle being greater than the second angle. In another embodiment of the needle of the present invention, the tip portion includes a third tapered region integral with the second tapered region and having a cross-sectional area which decreases progressively toward the needle tip in accordance with a third angle of inclination which is smaller than the second angle.

A new machine for and method of manufacturing fluted pin fasteners and the pins produced thereby are disclosed which utilize a circular grinding arrangement of a plurality of grinders which grind flutes into a threaded pin. An internally threaded collar threads onto the pin. When the collar engages a surface of a work piece, resistance to further threading increases. When sufficient resistance to threading occurs, the driver deforms the lobes of the collar radially inward toward the axis of the collar. Material of the collar positioned internally from the lobes responds to deformation of the lobes and flows radially inward into the flutes of the pin to lock the collar, pin, and work piece together. The driver then rotates freely, and a joint has been made with a predetermined axial load thereby locking the component parts together. The apparatus grinding the flutes into the pins comprises a vibratory feed bowl loading threaded pins into a four station rotary drum assembly rotationally driven by a drive mechanism through a plurality of stations.

A surgical needle has a top edge formed by two pressed faces located inside or outside of curvature from pressing a material blank made of austenitic stainless steel having fibrous texture and cutting edges formed on both sides of a base. The top edge is sharp at a needle point and the sharp needle point is constituted of fibrous texture formed at the surface layer of the material blank. Grinding marks extending crosswise formed on the face of the mold are transferred to the pressed faces. A mold constitutes plural faces forming projecting angles (angle between two intersecting faces is 180° or below, and the line at which the two faces intersect is made as a projecting line) along edges of the blocks made of two rectangular prisms, and constitutes a cavity by suitably contacting the edges of the blocks.

A process for progressively manufacturing cutting edge needles or wire members. Needle blanks or wire blanks are cut from a roll of wire and mounted to a carrier strip. The carrier strip and needles are moved through a succession of coining dies and at least one trimming die, wherein the first coining die is an open coining die and the one or more successive coining dies are closed coining dies. The needle blanks or wire members are optionally curved, heat treated and electrochemically treated resulting in cutting edge needles or wire members formed without a grinding step and without adversely affecting point ductility.

There is disclosed an apparatus for forming curved and rectangular bodied needle blanks from a length of needle stock which includes a generally cylindrical inner mandrel having a plurality of longitudinal channels formed in an outer surface thereof, the mandrel being dimensioned and configured for insertion within the length of needle stock. The apparatus also includes a plurality of broaches insertable into the longitudinal channels such that an edge of each broach projects radially outwardly of the mandrel to form a plurality of inner grooves on an inner surface of the length of needle stock. There is also provided structure for forming outer grooves in an outer surface of the length of the needle stock to form a substantially grooved length of needle stock, cutters for cutting the grooved length of needle stock to form rings of curved rectangular bodied needle blanks interconnected by web portions and structure for dividing the rings at the web portions to form a plurality of curved rectangular bodied needle blanks. There is also disclosed a method of forming needle blanks from a length of needle stock having a longitudinal cavity therethrough and defining a longitudinal axis by forming at least two inner grooves in an inner surface of the length of needle stock and substantially parallel to the longitudinal axis, forming a number of outer grooves, equal to the number of inner grooves, in an outer surface of the length of needle stock and in substantial radial alignment with the at least two inner grooves to form a grooved length of needle stock and sectioning the grooved length of needle stock to form individual needle blanks.

A continuous process for heat treating and cleaning and tempering martensitic stainless steel surgical needles is disclosed. The method comprises exposing the surgical needles to a partial vacuum at a temperature less than the heat treating temperature to remove volatile surface contaminant. Then the needles are heat treated in an argon gas environment at a pressure equal to or greater than 1.0 Torr. Next the temperature of the oven is lowered to temper the needles.

A steel pin is disclosed of a type to be forcibly driven into a steel substrate by using a powder-actuated tool. The steel pin has a substantially cylindrical shank and a substantially sharp point which extends from one end of the substantially cylindrical shank, which conforms substantially to a tangent or secant ogive except for a substantially spherical tip having a radius in a range of approximately 0.02 inch (approximately 5 millimeters) to approximately 0.03 inch (approximately 7.5 millimeters), which has substantially true concentricity, which has surface-texture irregularities with a roughness-height index value in a range from approximately 10 microinches (approximately 0.25 micrometers) to approximately 15 microinches (approximately 0.38 micrometers), and which appears to be substantially free of other surface imperfections when viewed under 60× magnification. The substantially cylindrical shank is joined to the substantially sharp point at a transition having a substantially smooth, continuously curved surface, and is knurled near the transition. The steel pin is made by deforming a length of steel wire as by forging or swaging, so as to form the steel pin with the substantially cylindrical shank and with the substantially sharp point, and reshaping the substantially pointed end as by barrel finishing the steel pin in a finishing medium.

A steel pin is disclosed of a type to be forcibly driven into a steel substrate by using a powder-actuated tool. The steel pin has a substantially cylindrical shank, and a substantially sharp point which extends from one end of the substantially cylindrical shank, which conforms substantially to a tangent or secant ogive except for a substantially spherical tip having a radius in the range of approximately 0.015 inch (approximately 3.75 millimeters) to approximately 0.03 inch (approximately 7.5 millimeters), which has substantially true concentricity, which has surface-texture irregularities with a roughness-height index value not greater than approximately 30 microinches (approximately 0.76 micrometers), and which appears to be substantially free of other surface imperfections when viewed under 60× magnification. Optimally, the ogive is a tangent ogive with an ogive radius approximately ten times the shank diameter and with an ogive length approximately twice the shank diameter, and the tip radius is approximately 0.1 times the shank diameter. The substantially cylindrical shank is joined to the substantially sharp point at a transition having a substantially smooth, continuously curved surface, and which is knurled near the transition. The steel pin is made by deforming a length of steel wire, as by forging or swaging, so as to form the steel pin.

A curved surgical needle and a method for producing the same from a solid sheet of material rather than from coiled wire including the steps of drilling a bore in one edge of the material, grinding an edge opposite the drilled edge to form a sharpened point, curving the material and cutting the material at a point of equal distance between each drilled bored to provide a surgical needle. A suture is then attached to the surgical needle, optionally lubricated, sterilized, and packaged by suitable means known in the art.

This invention relates to a method for manufacturing a needle attached suture and an apparatus therefor. A needle attached suture is obtained by inserting a suture into an insertion hole formed in the end of a needle N which is held by a needle retaining unit 16 and by swaging the end of the needle with the suture. The method and the apparatus have been developed to accurately position the end of the needle for swaging with the suture to stabilize the swaging strength between the suture and the needle. Before the swaging, the needle is held by the needle retaining unit 16, and the end of the needle N is pushed to a certain position by a rod 99 or its equivalent. Thereby, the end of the needle N relative to the needle retaining unit 16 is accurately positioned.

A hypodermic needle featuring a multi-beveled point geometry is disclosed. In one embodiment, the multi-beveled point features a primary bevel, a pair of tip bevels, and a pair of middle bevels each intermediate the primary bevel and a respective one of the tip bevels. The primary and middle bevels are provided at angles of inclination, measured between the central axis and a reference plane that are substantially identical. The tip bevels are formed at an angle of inclination respective to the central axis which is not equal to the angle of inclination at which the primary and middle bevels are formed. The resulting five-beveled point geometry contributes to a more continuous bevel face free of abrupt intercepts or transitions between the respective bevel faces, lessening the penetration force required to urge the needle point through skin, flesh, or other material.

A new machine for and method of manufacturing fluted pin fasteners and the pins produced thereby are disclosed which utilize a circular grinding arrangement of a plurality of grinders which grind flutes into a threaded pin. An internally threaded collar threads onto the pin. When the collar engages a surface of a work piece, resistance to further threading increases. When sufficient resistance to threading occurs, the driver deforms the lobes of the collar radially inward toward the axis of the collar. Material of the collar positioned internally from the lobes responds to deformation of the lobes and flows radially inward into the flutes of the pin to lock the collar, pin, and work piece together. The driver then rotates freely, and a joint has been made with a predetermined axial load thereby locking the component parts together. The apparatus grinding the flutes into the pins comprises a vibratory feed bowl loading threaded pins into a four station rotary drum assembly rotationally driven by a drive mechanism through a plurality of stations. There is a feed station to receive pins into drum assembly, a grind station to grind the pins, and an eject station to eject the ground pins. The circular arrangement of grinders is mounted on a table which is translated up and down by an air spring against a cam wheel to grind the pins located at the grinding station.

A swaging apparatus for attaching sutures to surgical needles includes at least a first die and a second die. The first die has a first member, which includes a first surface, and a second member, which includes a second surface. The second member is movable relative to the first member between an extended position, in which the second surface extends beyond the first surface, and a retracted position, in which the second surface does not extend beyond the first surface. The second die has at least one surface and is movable relative to the first die between a remote position and an adjacent position. When the second die moves relative to the first die from the remote position towards the adjacent position, the second member of the first die is caused to move from the extended position towards the retracted position, and the surfaces of the first and second dies cooperate with one another so as to swage a surgical needle positioned between the first and second dies. The second member of the first die is movable to the retracted position when the second die abuts the first die. In this manner, surgical needles of many different types or sizes can be swaged by the swaging apparatus.

A tip portion of a needle main body having an edge point includes a first slant surface slanted at 10-18 degrees with respect to the axis of the needle main body, a pair of second slant surfaces slanted at 16-23 degrees, and a pair of third slant surfaces slanted at 19-27 degrees. The ratios of the lengths of the first, second, and third slant surfaces are set to be 40-50%, 5-15%, and 35-55%. At the time of forming the second slant surfaces and the third slant surfaces, a grinding wheel or the needle main body is turned relative to the other in a horizontal plane so that the direction of axis of the grinding wheel and the direction of axis of the needle main body are in a twisted or distorted relationship from a substantially orthogonal relationship such that the radial outer sides of the second and the third slant surfaces are included downwardly.

A quilting needle for achieving substantially uniform stitches in a multi-layer fabric/batten quilting substrate. The needle is formed as an elongated straight slender needle body having an eyelet at one end thereof sized for receiving a quilting thread therethrough and a sharp quilting fabric piercing point at another end of the needle body. A viewable stitch size guide is permanently disposed on the needle body so as not to disrupt the smooth needle body surface and is positioned from the point a distance equal to a desired stitch size. Successive stitches formed into the substrate of uniform size or length when the needle body is consistently pierced through the substrate to a depth defined when said stitch size guide just touches or meets and aligns with an obverse surface of the substrate before piercing the point into a reverse surface of the substrate to complete each stitch.

An apparatus for forming armed sutures has a swaging station for receiving, holding and swaging needles that are deposited therein. A linear motor drives a suture insertion gripper, which pulls suture from a supply reel and inserts a cut end thereof into a needle held in the swaging station. A ganged needle transfer assembly with a plurality of spaced needle gripper units carries needles along a line substantially at right angles to the suture line and transfers them to and from the swaging station and other needle processing stations. A precisor orients needles prior to placement in the swaging station and a pull test assembly tests armed sutures in both destructive and non-destructive modes. Both ends of the production line may be automated, e.g., by robots which load and offload needles prior to and after swaging, respectively. The apparatus is capable of forming double armed sutures by using a rotatable mount for the suture insertion gripper and a secondary, loop gripper. A suture transfer gripper extending up to the suture from a multi-tiered stack of slide tables. The suture transfer gripper cooperates with the suture insertion and loop grippers to hold the suture during cutting, insertion and transfer to the pull test apparatus and thereby protects the suture during processing.

A method for manufacturing a surgical needle devoid of a grinding process includes the steps of swaging a needle blank to define a substantially tapered or conical needle end, pressing the tapered needle to form a plurality of intersecting surfaces and forming cutting edges along the lines of intersection of the intersecting sides. The needle may be subjected to an etching process (e.g., an acid bath) to sharpen the cutting edges and/or provide a matte finish on the needle. The needle produced by the novel process is extremely sharp and durable, and exhibits an enhanced retention of sharpness relative to conventional ground needles over periods of prolonged use.

A process for manufacturing a surgical needle incorporates at least one pressing operation which, preferably, in conjunction with a trimming and/or etching process, ultimately forms the sharpened needle end. The grinding operation in the preferred process does not produce the primary sharpened edges of the needle, but, rather is incorporated, in one instance, to reduce excess needle material prior to the pressing operation. Consequently, the amount of flash material generated during pressing is substantially reduced. This feature desirably enhances the subsequent trimming and etching operations, and produces a needle which is extremely sharp, durable and exhibits an improved retention of sharpness over periods of prolonged use.

In a manipulator needle portion defect repairing method, the existence of an abrasion or a fracture in a needle portion for holding a sample at an end of a manipulator disposed in an FIB device is confirmed using a microscope function of the FIB device. The abrasion or the fracture in the needle portion is then repaired by chemical vapor deposition using a focused ion beam of the FIB device.

Surgical needles are produced by immersing a needle possessing a distal end surrounded at least in part by flash material and a body portion in an acid bath according to a predetermined sequence, wherein the distal end of the needle is exposed to the acid bath under conditions sufficient to remove flash material from the distal end of the needle and the body portion of the needle is exposed to the acid bath under conditions sufficient to provide a matte finish on at least a portion of the body portion of the needle.

A process for manufacturing a surgical needle incorporates at least one pressing operation which, preferably, in conjunction with a trimming and/or etching process, ultimately forms the sharpened needle end. The grinding operation in the preferred process does not produce the primary sharpened edges of the needle, but, rather is incorporated, in one instance, to reduce excess needle material prior to the pressing operation. Consequently, the amount of flash material generated during pressing is substantially reduced. This feature desirably enhances the subsequent trimming and etching operations, and produces a needle which is extremely sharp, durable and exhibits an improved retention of sharpness over periods of prolonged use.

A method of mechanically treating alloy metal surgical needles to improve bending strength is disclosed. The needles are curved and reverse-curved in this method to improve bending strength.

A method of stress relieving drilled surgical needles is disclosed. At least the metal about a drilled bore hole is heat treated to relieve stress without annealing.

A method of actuating an assembly of a transmission, with which are associated a plurality of actuators with whose help the assembly can in principle be actuated, such that out of the actuators available in principle for actuation, a control unit selects at least one actuator for the actual actuation and activates the selected actuator with an output signal in such manner that a status parameter of the actuated assembly corresponds to or follows a control-side nominal value, such that out of the actuators available in principle for actuating the assembly, the control unit selects at least one actuator for the actual actuation of the assembly in such manner that, for all the actuators available in principle for actuating the assembly over the operating life of the transmission, the extent of their utilization is approximately uniform.

The present invention relates to an implement, in particular an excavator or machine for material handling, with an element movable via at least one working drive, wherein at least one energy recovery cylinder is provided for energy recovery from the movement of the movable element, which includes a chamber filled with gas, wherein the actuation of the implement is effected in dependence on the directly or indirectly determined temperature of the gas in the chamber filled with gas.

Method of indicating the position of a hydraulically actuated armature, comprising an adjust cylinder for actuating the armature, connected by at least one pressure medium line to an adjustment valve through which the pressure medium line can be switched between pressure-causing forward flow and pressure-less backward flow, wherein the flow through the pressure medium line is converted into a number of electric pulses and the number of pulses reflecting the flow is processed in a program in an indicator unit such that the number of pulses occurring in a predetermined adjustment travel when the flow in the pressure medium line is pressure-less is calculated as being the same adjustment travel as when the pressure medium line is switched to be the pressure line.

The invention relates to a method for constructing a gas-filled double-acting hydraulic cylinder (1) with gas spring action, comprising: —a cylinder sleeve (3) with a cylinder bottom (3a) and cylinder head (3b) —a piston/piston rod assembly (5) a hydraulic fluid seal on the piston (9) —a connection for the head-side chamber (13) to a hydraulic line; —a connection for the bottom-side chamber (15) to a hydraulic line, —a gland (20) with a bore, the gland being attached between the cylinder bottom (3a) and the piston (9), the piston rod (7) extending over the entire stroke of the piston rod through the bore, wherein the gland comprises two seals —(25), one for providing a seal with the cylinder sleeve (3) and one for providing a seal with the piston rod.

A system comprises a first piston comprising a first piston shaft and a first drive pin. A first piston cylinder comprises a first body and a first groove, wherein the first groove defines a first aperture, the first aperture oriented axially along the first body and configured to receive the first drive pin. The first body encloses the first piston and allows the first piston to travel axially within the first piston cylinder. A drive shaft comprises an axis, a drive groove, and a surface, wherein the drive groove forms a continuous channel along the surface and receives the first drive pin. In one embodiment, a first distribution wheel comprises a first face, a second face, a first inlet aperture, and a first outlet aperture. The first distribution wheel couples to the first piston cylinder and to the drive shaft at a first end of the drive shaft, and rotates axially with the drive shaft along the axis of the drive shaft. The first inlet aperture allows hydraulic fluid to pass through the first face and the second face and the first outlet aperture defines a groove on the second face.

The invention relates to a neutral setting apparatus for adjustable hydraulic machines, in particular the adjustment of the neutral position of a servo valve. In particular, the invention relates to servo adjustment devices with mechanically adjustable control pistons, wherein the forces necessary for this can be applied mechanically, electro-magnetically, pneumatically or hydraulically. The invention relates to a neutral setting apparatus of an adjustable hydraulic machine, with a housing in which a mounted input shaft is arranged, to one end of which a torque can be applied for rotating the input shaft about an axis. Thus providing a robust and cost-effective setting mechanism for the neutral position of a servo valve.

The disclosed invention introduces an efficient lifting mechanism for reciprocating vertically a load system, the load consisting of the aggregate weights of a cargo payload in conjunction with “dead weights” of moving parts of the lifting apparatus. The disclosed invention uses a hydro-pneumatic linear actuator to lift the load and a pressurized accumulator, acting as a force intensifier. The pressurized accumulator, acting as a self-contained stored energy source, provides to the actuator adequate power to lift the “dead weights” plus part of the cargo payload. An external power source provides to the actuator adequate power to lift the remainder of the cargo payload. The disclosed invention saves significant amounts of power and energy in applications in which the “dead weights” are sizable compared to the cargo load. The disclosed invention provides also exceptional means for accurate motion control of the cargo payload.

In a stroke-limiter equipped integral power steering apparatus, a valve body of a spring-loaded-plunger-equipped limiter valve is configured to enable a position of the valve body relative to a housing to be adjusted in a longitudinal direction of the valve body via an intermediate sleeve.

A method and apparatus for a fluid damper comprising a first fluid-filled chamber, a second chamber filled with a fluid having variable flow characteristics and at least partially displaceable by the first fluid, and a gas chamber, the gas chamber compressible due to the displacement of the second chamber. In one embodiment, the fluid in the second chamber is a variable rheology fluid.

The present invention relates to devices and systems that alter intracranial compliance, cerebral blood flow and/or intracranial pressure pulsatility/waveform by oscillating the contraction and expansion of a compressible composition within the cranial or spinal cavities such that they increase intracranial capacity. The contraction and expansion of the compressible composition in the oscillating compliance devices can be due to an individual's intracranial pressure, the result of the expansion and compression of a reservoir which is mediated by the contractility of the heart or driven by a pump gaited to a biorhythm. The invention also relates to methods for protecting an individual's brain from abnormal arterial pulsations and for altering an individual's cerebral blood flow using the devices and systems of the invention. The oscillating compliance devices can be used to treat several diseases and/or conditions characterized by altered/abnormal intracranial compliance, cerebral blood flow and/or intracranial pressure pulsatility/waveform, including hydrocephalus, stroke, dementia and migraine headaches, vasospasms, congestive heart failure, cardiopulmonary bypass or carotid endarterectomy.

The invention relates to an energy-efficient apparatus driven by compressed air and equipped with a dual piston function for tensioning, or clamping, or centering, or punching, or welding, or clinching, for use in body construction in the automotive industry. The apparatus is driven by a pressurized fluid, in particular by compressed air. It is shown how a significant amount of operating costs can be saved while, at the same time, conserving the environment and consuming a low amount of pressurized fluid, in particular compressed air. In addition, the pivoting angle of a toggle joint assembly and thus of an apparatus connected thereto, for example, a tensioning arm of a toggle tensioning apparatus, can be continuously adjusted in both directions while, at the same time, adjusting a sampling device using sensors, for example, microswitches, or inductive switches, or pneumatic switches, or limit switches.

A sensor coupler adapted to operatively connect a sensor to a piston-cylinder assembly. The sensor coupler includes a first end member and a second end member. The first end member is disposed on a port of the piston-cylinder assembly, in communication with the sensor, and the second end member is disposed in a cylinder chamber of the piston-cylinder assembly. Further, one or more cables are extending between the first end member and the second end member. The one or more cables are configured to transmit signals indicative of a position of a piston in the piston-cylinder assembly to the sensor. The sensor coupler further includes a biasing member to connect the first end member and the second end member.

An energy-saving valve includes a spool-driving unit which changes the position of a spool to a position at which compressed air is discharged from a first output port without pressure control and includes a pressure control unit which changes the position of the spool to a position at which compressed air is discharged from a second output port in a predetermined pressure level due to pressure control. The pressure control unit includes a pressure control piston, a pressure-receiving surface which enables air pressure in the second output port to act on the pressure control piston, a cylinder chamber, a pressure control channel, and an elastic member which applies biasing force to the pressure control piston in a direction opposite to the action of air pressure on the pressure-receiving surface to determine pressure.

A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a pump, a tank, and an actuator. The hydraulic control system may also have at least a first valve configured to control fluid flow between the pump, the tank, a first chamber of the actuator, and a second chamber of the actuator; a second valve fluidly disposed between the second chamber and the tank; and a third valve fluidly disposed between the first and second chambers. The hydraulic control system may further have a controller configured to selectively cause the second valve to block fluid flow from the second chamber of the actuator to the tank, and to selectively cause the third valve to fluidly communicate the first and second chambers of the actuator when the second valve blocks fluid flow from the second chamber of the actuator to the tank.

A manual release valve is provided for a electro-hydraulic actuator of the type including a piston movable in a cylinder and defining a piston side chamber and a rod side chamber, the valve threadedly attached to the housing of the actuator and extending at least partially within the fluid housing conduits, the valve moveable from a closed position fully seated in the housing to an open position for fluidly connecting both the piston side chamber and the rod side chamber to the reservoir, the valve further including a pressure relief portion that is operable when the valve is in the closed position for relieving pressure from at least one of the piston side chamber or the rod side chamber.

A radial thermal engine with an improved valve system is disclosed herein comprising intake and exhaust port valve assemblies fluidly connected to respective intake and exhaust ports contained within a cylinder head assembly. Each intake and each exhaust port valve assembly comprises at least one rotatable port cover having spaced apart openings which are periodically alignable to the intake and exhaust ports, respectively.

The invention relates to a method for the impregnation of a product consisting of fibrous material and formed from a continuous web (22), the method comprising at least one first step of cutting out a specific zone (24) of the continuous web (22) and at least one second step of applying an impregnation product to the specific zone (24), the first and second steps being carried out simultaneously or virtually simultaneously.

This disclosure provides for pressure limiting a hydraulic system to a desired pressure value by a particular circuit by controlling and closing the compensator when the desired pressure setting is achieved. Closing the compensator will reduced the pressure head and flow in the circuit resulting in improved efficiency. One illustrated embodiment of the disclosure provides a relief valve in the pilot signal for a compensator. The method relates to limiting the pressure on an open side of the compensator, such that the pressure on the other side closes the compensator thereby limiting the pressure and also flow in the hydraulic circuit. In other words, the pressure on the open side is limited by the relief valve. Thus, the pressure on the other side increases thereby regulating the flow and pressure through the compensator. In another embodiment of the disclosure, instead of reducing the pressure on the open side, the pressure on the closed side is increased, thereby controlling the flow and pressure of the hydraulic circuit. The pressure can be increased by a pump or any other suitable mode.

A pump assembly having an air motor includes a valve connected to a motive fluid inlet of the air motor. The valve shifts between a first position, in which a flow of motive fluid is directed into a pilot port, through a two way pilot conduit and into a pilot chamber portion, and a second position, in which the flow of motive fluid is inhibited from flowing into the pilot port through the two way pilot conduit and into the pilot chamber portion, and in which fluid in the pilot chamber portion flows out through the two way pilot conduit and is directed by the valve to exhaust. The valve is connected to a programmable logic controller, so that the valve is shifted between the first position and the second position in response to the programmable logic controller.

Valve control device includes a body with a longitudinal axis, a control member housed at least partially in the body in a bottom portion along the longitudinal axis, a piston movable along the longitudinal axis and housed in a portion of the body forming with the piston a control chamber of the piston, an element movable in rotation with respect to the longitudinal axis on a top portion of the body, and sealing means between the movable element and the control chamber in the area of the connection port and/or of the passage.

A fluid-working machine has a working chamber of cyclically varying volume, high and low pressure manifolds, and high and low pressure valves for regulating the flow of fluid between the working chamber and the high and low pressure manifolds respectively. A controller actively controls at least one said valve to determine the net displacement of working fluid of the working chamber on a cycle by cycle basis. At least one said valve is a variable timing valve and the controller causes the valve to open or close at a time determined taking into account one or more properties of the performance of the fluid working machine measured during an earlier cycle of working chamber volume.

A brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type having a brake booster. In order to provide a brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, which on the one hand fulfills the statutory requirements care and which on the other hand is inexpensive to produce, it is proposed according to aspects of the invention, that the brake booster be provided as a travel-controlled brake booster, so that when not in the “brake-by-wire” operating mode the brake pedal is decoupled from feedback forces of the brake actuating unit, and the return force is simulated by the pedal travel simulator even when not in the “brake-by-wire” operating mode.

A brake booster with regenerative brake force generation comprising a force input element coupled to a brake pedal. A chamber arrangement having a vacuum chamber and a working chamber that are separated from one another by a movable wall. A control valve actuated in accordance with a displacement of the force input element. The working chamber is connectable selectively to the vacuum chamber and the atmosphere to generate and reduce a differential pressure at the movable wall. The control valve has a control valve housing that is connected for joint movement to the movable wall. In a first actuation phase of the brake booster from its rest position, the force input element is displaceable relative to the control valve housing by an idle travel, in which the control valve remains non-actuated to suppress a build-up of a differential pressure at the movable wall.

In a reciprocating piston compressor with delivery rate control, the electromagnetic actuating device (3) of the valve lifter (2) has a separate positioning drive (10) for adjusting the working stroke range of the magnetic actuator (5) used, whereby this can be chosen to be small and highly dynamic and only low power losses occur.

An arrangement for providing a throttle cross-section for a fluid flow. The throttle cross-section can be varied depending on a pressure difference present across the throttle cross-section. The arrangement is designed such that the polarity of the pressure difference, by which the throttle cross-section can be varied and/or changed. It is thereby possible to use the arrangement for fluid flows that alternate in the flow direction thereof.

A hydraulic system is provided, having a pump, operably connected to a motor. It also comprises a controller-driven hydraulic actuator, operably connected to the pump and a hydraulic valve, operable to direct hydraulic fluid to and from either a rod side or a cylinder side of the hydraulic actuator. Rod and cylinder side pressures are pre-defined based on the instantaneous acceleration or deceleration required. Decelerating the hydraulic actuator could involve maintaining the current pressure in the meter-out side of the hydraulic actuator and decreasing the current pressure in the meter-in side by varying the speed of the pump. Deceleration of the hydraulic actuator could also include decreasing pressure on the meter-in side of the hydraulic actuator at a higher rate than on the meter-out side. Acceleration is achieved using a similar approach.

In a fluid pressure cylinder, a piston is displaced in an axial direction under the action of a pressure fluid. A circular protrusion, which projects toward the piston along an axial direction of the cylinder tube, is formed on an inner end surface of a collar member constituting part of the fluid pressure cylinder, a concavity, which can be fitted externally over the circular protrusion, is formed on the piston, and an annular groove is formed on an inner circumferential edge of an end plate. By the piston coming into contact with the end plate, a pressure receiving chamber is formed between the piston and the annular groove, together with an opening of a second port on an inner side of the cylinder tube being closed to a maximum of 90%.