Abstract: The present invention relates to a brake system for a vehicle. The proposed brake system (1) comprises an actuation unit for actuating wheel brakes of the vehicle in a normal operating mode of the brake system (1). Further, the system (1) comprises a brake cylinder (2) for pressurizing the wheel brakes of the vehicle in an emergency operating mode of the brake system (1). The brake cylinder (2) comprises a brake cylinder housing (4) and a push rod (3) being displaceable within the brake cylinder housing (4) by operation of a brake pedal (5). The brake cylinder (2) further comprises a piston (14) movably arranged within the brake cylinder housing (4). The piston (14) has a first surface and a second surface opposite the first surface. A hydraulic chamber (11) is formed within the brake cylinder housing (4) between the first surface of the piston (14) and an inner surface of the brake cylinder housing (4). The hydraulic chamber (11) is configured for being selectively fluidly connected with the wheel brakes.

Abstract: A relay valve (10) for a pneumatic valve unit (14), for example for a braking system of a utility vehicle, has a first assembly component (18) and a second assembly component (20). A hollow cylindrical guide portion (28) of a piston (24) of the relay valve (10) is received, in an axially guided manner, in the first assembly component (18). The second assembly component (20) includes additional valve components and the venting region of the relay valve (10). At least the first assembly component (18) and the second assembly component (20), when assembled, form a preassembly unit (26) first assembly component (18) and are joined by a bayonet connection (30). The preassembly unit (26) is inserted into a housing (12) of the valve unit (14), The interior of the housing is delimited by a cup-shaped inner wall (32), and the preassembled unit is fastened therein.

Abstract: The invention relates to a device that is always open for the pressure medium for reducing pressure pulsations and that can be switched between a pressure chamber of a slave cylinder and a pressure chamber of a master cylinder of a hydraulic force transmission system for motor vehicles. The device has an additional line section in the form of a channel having an opening on the slave cylinder side, an opening on the master cylinder side, and a channel length equaling a multiple of the direct distance between the two openings, and a volume receiver that can be elastically deformed under pressure, wherein the channel and the volume receiver are combined into an assembly in a housing. The result according to the invention is a device that not only has very good vibration dampening properties, but is also very compact and has a cost-effective design.

Abstract: In some aspects, a master cylinder assembly for vertical lift aircraft is configured to move pressurized fluid through a conduit in response to applied movement of an input lever. A low pressure relief valve can be connected to a first conduit to limit pressure to a low level. An isolation valve can be connected to the first conduit and configured to isolate the low pressure relief valve from the conduit when engaged. A high pressure relief valve can be connected to a second fluid conduit to limit pressure to a high level. In some aspects, a rotor brake actuator is fluidly connected to the first conduit and the second conduit and configured to engage a rotor brake in response to hydraulic fluid pressure.

Abstract: A brake fluid reservoir is connected to a master cylinder by a neck which is arranged in an upper chamber of the master cylinder. Holes extend through a surface of a piston, opening to a pressure chamber. The piston extends through a bore hole of the master cylinder. A drill hole extends through an interior wall of the master cylinder, opening into the bore hole, thereby providing communication between the fluid reservoir and the pressure chamber. A floating orifice plate is arranged within the upper chamber, between the neck of the brake fluid reservoir chamber and the drill hole, such that the orifice plate forms a baffle that limits a flow rate of liquid from the brake fluid reservoir chamber to the pressure chamber; and includes supports pressing against a surface of the interior wall of the master cylinder and arranged around the first side of the drill hole.

Abstract: A pneumatic booster (40) disposed between a brake pedal (5) and a master cylinder (7) includes a cylindrical member (60) provided on an outer circumferential side of an output rod (58). A seal member (62) seals between an outer circumferential side of the cylindrical member and a cylindrical portion of a front shell, and an O-ring seals between the cylindrical member and the output rod. The cylindrical member causes a differential pressure between a negative pressure chamber (A) and an atmosphere chamber (C) to be applied to a valve body (46). One axial side of the cylindrical member is configured to cause an atmosphere pressure to be applied to the valve body by abutting against a cylindrical protruding portion of the valve body, thereby pushing the valve body with the aid of the differential pressure in the direction as a biasing direction of a return spring.

Abstract: A braking device for a vehicle is provided which is equipped with a hydraulic booster. The hydraulic booster includes a master cylinder, a braking simulator, and an input piston. The input piston is disposed in the master cylinder in connection with a brake actuating member such as a brake pedal and is moved in response to a braking effort applied to the brake actuating member to drive a spool valve which switches among a pressure-reducing mode, a pressure-increasing mode, and a pressure-holding mode. The braking simulator works to urge the input piston rearward and is disposed inside a cylindrical cavity of the master cylinder of the hydraulic booster. This layout improves the mountability of the braking device in vehicles.

Abstract: A pump housing has at least two inlet valve openings located in a first row, at least two outlet valve openings located in a subsequent second row, and at least one high-pressure switching valve opening and at least one changeover valve opening located in a further subsequent fourth row. At least one connection for a wheel pressure sensor is positioned in a third row between the second and fourth rows. At least one connection for a master cylinder pressure sensor is positioned in a fifth row following the fourth row.

Abstract: A hybrid or electric vehicle includes a hydraulic brake system having an active vacuum booster with an active boost control valve actuated by at least one controller. An isolation valve is disposed in a fluid circuit that fluidly connects a master cylinder to hydraulic brakes. A brake pedal is capable of moving in an initial deadband displacement range when initially depressed by an operator of the vehicle. While in the initial deadband displacement range, the controller selectively activates the isolation valve to inhibit fluid flow from at least a portion of the fluid circuit to the master cylinder based at least upon an operating state of the active boost control valve.

Abstract: A vehicle brake system includes a cylinder, a master piston including a pressure applying piston and a projection portion, a servo chamber, a contact/separation determining means determining a separated state and a contact state between the input piston and the master piston, a pilot pressure generating device generating a pilot pressure, a servo pressure generating device, a servo pressure measuring device measuring a servo pressure, and a master pressure estimating means estimating a master pressure from the pilot pressure and a first servo ratio, which is a cross-sectional area ratio between a first pilot chamber and a servo pressure generating chamber, in a case of the separated state, and estimating the master pressure based on the servo pressure, the pilot pressure and a second servo ratio, which is a cross-sectional area ratio between a second pilot chamber and the servo pressure generating chamber, in a case of the contact state.

Abstract: A pushing force controlling apparatus for a pedal simulator that includes a simulator cylinder in which a first pipe and a second pipe extending from a master cylinder are connected to a front side and a rear side thereof, respectively. A first solenoid valve and a second solenoid valve are installed in the first pipe and the second pipe, respectively and a first piston and a second piston are disposed at a front side and a rear side of an interior of the simulator cylinder. A buffering member is installed between the first piston and the second piston, and pedal pushing force characteristics are controlled by variably setting a position of the second piston in the simulator cylinder using an amount of fluid provided from the master cylinder during an operation of a pedal.

Abstract: A gas supply system for a mechanical seal turns on the gas supply at a pressurized flow rate at the time of compressor case pressurization and remains on during compressor rotation until pressure is adequate. The gas supply system has an intensifier that includes a pair of mechanically inter-connected pneumatic pressure cylinders which comprise a drive cylinder that affects movement of a boost cylinder wherein the displacement of these mechanically interconnected pistons in the drive cylinder and boost cylinder intensifies the pressure being discharged by the boost cylinder and supplied as a barrier fluid to the mechanical seal. The intensifier uses a control valve and operating system which includes a fast-acting 5/2-way solenoid valve having a feedback loop connected to a control system which includes a micro-processor that controls valve actuation.

Abstract: The present invention relates to a hydraulic control device for an antilock brake system, which is capable of maintaining a certain amount of braking performance even in the event of a disturbance or repeated use, by enabling the restriction of the displacement of a control bolt to a certain range. Therefore, through the present invention, braking ability is not lost under any circumstances, and accidents caused by a loss of braking function due to the malfunctioning of a hydraulic control device for an antilock brake system can be averted.

Abstract: A control unit of a hydraulic brake apparatus for a vehicle including a housing, a switching control valve, pressure increase control valves, pressure decrease control valves, a reservoir, a pump driven by a motor, a first passage, a second passage, an inner bore and a passage forming member being liquid-tightly fitted into the inner bore in order to form an extended ring-shaped passage, wherein the extended ring-shaped passage forms a part of the first passage, and the switching control valve, the pressure increase control valves and the outlet valve are connected to the extended ring-shaped passage, and a part of the second passage is formed within the passage forming member, and end portions of the part of the second passage are connected to the switching control valve and the switching valve.

Abstract: A rim brake having a right arm and a left arm respective with one upper and one lower longitudinal portion separated from one another by a pivot bearing. The lower longitudinal portion is provided for holding a brake pad and the upper longitudinal portion engages with at least one hydraulic cylinder through a wedge element. The hydraulic cylinder is disposed between the right arm and the left arm and is configured to move the wedge element. A method for the installation of a hydraulic brake having a master unit and a slave unit connected to a hydraulic line is also provided.

Abstract: The braking control device for a vehicle is adapted to be used for a vehicle brake device and it is an object of the present invention to prevent an operator of the vehicle from feeling of any an unpleasant feeling by reducing an ineffective operating amount by which no braking force increases in response to the increase of the brake operating amount. The braking control device includes a controlling portion for changing a servo performance to an ineffective operating amount reducing servo performance which is closer to the increase ratio of the hydraulic pressure braking force relative to the increase of the brake operating amount after the input piston has been in contact with the output piston when the brake operating amount reaches to the servo performance change operating amount which is smaller than the assisting limit operating amount.

Abstract: A master cylinder includes a cylinder body which an operating fluid is introduced from a reservoir, a piston which is slidably fitted in the cylinder body and defines a pressure chamber inside the cylinder body, a supply pathway which is formed in the cylinder body and supplies the operating fluid from the reservoir to the pressure chamber, a bypass pathway which bypasses the supply pathway and allows the reservoir to communicate with the pressure chamber, and a check valve which is installed in the bypass pathway and opens a valve when the pressure inside the pressure chamber is lower than the pressure of the reservoir.

Abstract: A hydraulic brake apparatus includes a master cylinder pressurizing brake fluid in a pressure chamber and outputting a hydraulic pressure to a wheel cylinder of a first brake circuit, and a pressure control valve controlling a hydraulic pressure of an auxiliary hydraulic pressure source outputting the controlled hydraulic pressure to a wheel cylinder of a second brake circuit, wherein a master cylinder piston includes a first passage which hydraulically connects the pressure chamber and a reservoir, and a switching valve which closes and opens the first passage, and wherein a throttle means and a check valve, which allows the brake fluid to travel only from the reservoir to the pressure chamber, are hydraulically provided in parallel with each other at the first passage at a position between the switching valve and the reservoir.

Abstract: A valve intended to disconnect, in specific circumstances, the braking of the front wheels, and/or of a trailer whose braking system is connected through a trailer braking valve, for the braking system of a farm tractor or similar vehicle which includes two master cylinders, operated by two separate braking pedals, directly controlling the braking of the rear wheels, and controlling the braking of the front wheels and/or the braking device of the trailer through the disconnection valve. The disconnection valve includes a body, first and second inlet connections connected to the two master cylinders, and a delivery connection connected to a braking circuit of the front wheels and/or to the trailer brake valve. The valve body has a bore wherein is installed one movable piston subjected to the action of pressure applied to the first inlet connection.

Abstract: In a master cylinder, a supply passage for supplying operating liquid from a reservoir (2) to a pressure chamber (6) is provided in a cylinder body (3) coupled with the reservoir. A bypass passage (37) for bypassing the supply passage and connecting the reservoir and the pressure chamber is further provided, and a check valve (34) adapted to open when a pressure in the pressure chamber is lower than that in the reservoir is disposed in the bypass passage. A valve case (38) containing a valve body (41) of the check valve includes a valve seat (40) and a cylindrical wall (45) for slidably guiding the valve body which are integrally formed as a single member.

Abstract: A fast fill braking system includes a master cylinder, a primary pressure chamber having a first chamber portion located forwardly of a second chamber portion, the first chamber portion having a diameter larger than a diameter of the second chamber portion, and a primary piston including a first piston portion positioned within the primary pressure chamber and a second piston portion extending out of the primary pressure chamber, the first piston portion having a diameter (i) larger than a diameter of the second piston portion, and (ii) complementary to the diameter of the second chamber portion.

Abstract: In order to make the idle stroke which occurs as small as possible in a master cylinder, in particular for a clutch, actuating or brake system of a vehicle, comprising a cylinder housing with a piston bore, a piston arranged in the piston bore and having an end side facing a cylinder chamber and at least one afterflow opening which leads from a piston skirt surface through a piston wall to the cylinder chamber at a distance from the end side and adjoins an afterflow space in a pressure equalization position of the piston so that in the pressure equalization position hydraulic medium can run on into the cylinder chamber in order to equalize the pressure, and an inner sealing element which is arranged between the housing and the piston in the area of the piston bore and limits the cylinder chamber, it is suggested that the afterflow space be arranged between the sealing element and the piston skirt surface on a side of a sealing lip of the sealing element facing away from the cylinder chamber and that in the pr

Abstract: Disclosed is a hydraulic brake booster. A relative movement structure of a control plunger and an output shaft is modified in such a manner that the output shaft operates in the control plunger, thereby reducing the overall length of the booster and the manufacturing cost. An inner circumferential surface of a guide of the control plunger does not make contact with an outer circumferential surface of the output shaft, so that the vibration and the impact caused by the contact between the control plunger and the output shaft are not delivered, thereby improving brake pedal feeling. The control plunger includes a guide having a groove, and an inner diameter of the guide is greater than an outer diameter of the output shaft. The control plunger and the output shaft perform relative movement in the overlap state therebetween, thereby reducing the overall length of the booster and the manufacturing cost.

Abstract: A hydraulic element, in particular for arranging in a pressure line between a master cylinder and a slave cylinder of a hydraulic clutch actuating arrangement, having a housing which has a master-cylinder-side hydraulic connection and a slave-cylinder-side hydraulic connection and which holds a valve arrangement, a simpler design is obtained in that the valve arrangement has two valve bodies which are mounted in a floating fashion in the housing and which can be moved relative to one another counter to the force of a spring.

Abstract: The invention relates to a piston pump, in particular for brake pressure regulation in a hydraulic vehicle brake system. To control the pressure medium flow, piston pumps of the known type have an outlet valve which is accommodated in a valve lid. An outflow duct of the piston pump opens out into a pressure fluid conduit of a pump housing. As viewed in the direction of the longitudinal axis of the piston pump, the pressure fluid conduit is arranged above an end, which is situated in the interior of the pump housing, of the valve lid. The pressure fluid conduit is therefore at a relatively great distance from an outer side of the pump housing. The invention is directed to a special embodiment of the outflow fluid conduit of the piston pump, which makes it possible for the distance between the pressure fluid conduit and the outer side of the pump housing to be reduced. The pump housing may thereby be optimized in terms of installation space.

Abstract: The invention relates to a control valve for a vehicle brake system having a first fluid connection, a second fluid connection, and a decompressed connection toward the atmosphere. An adjustment spring applies a spring force to a control piston moving in longitudinal direction on the decompressed side, the control piston completely releasing a fluid connection between the first fluid connection and the second fluid connection in an initial position, and to a corresponding vehicle brake system having such a control valve. According to the invention the control valve includes a valve body having a seal seat and a sealing element coupled to a control piston. A sealing region of the sealing element interacts with the seal seat of the valve body in order to limit an effective pressure present on the second fluid connection to a predetermined maximum pressure value. The effective diameter of the control piston is greater than or equal to an effective diameter of the sealing element.

Abstract: Disclosed herein is a master cylinder for a vehicle. The master cylinder includes a housing, a piston, inlet ports and a seal. The housing has therein a liquid pressure chamber to contain oil. The piston reciprocates in the liquid pressure chamber to control the pressure in the liquid pressure chamber. A front end of the piston has a stepped structure. The inlet ports are provided in the housing so that oil is supplied into the liquid pressure chamber through the inlet ports. The seal is seated into a seating depression which is formed in the inner surface of the housing. The seal opens or closes a flow path of the oil depending on whether the seal is brought into contact with the piston. The oil flows into the liquid pressure chamber along the stepped outer surface of the piston through a space defined between the piston and the seal.

Abstract: A hydraulic element, in particular for arranging in a pressure line between a master cylinder and a slave cylinder of a hydraulic clutch actuating arrangement, having a housing which has a master-cylinder-side hydraulic connection and a slave-cylinder-side hydraulic connection and which holds a valve arrangement, a simpler design is obtained in that the valve arrangement has two valve bodies which are mounted in a floating fashion in the housing and which can be moved relative to one another counter to the force of a spring.

Abstract: A brake system for a vehicle including a master cylinder in which a front pressure chamber and a rear pressure chamber are defined by movably supporting an input piston and a pressure piston in a cylinder. A high-pressure supply pipe of an accumulator is coupled to wheel cylinders via hydraulic supply pipes, and coupled to the rear pressure chamber via a hydraulic supply pipe and a second hydraulic pipe. Pressure booster valves and pressure reducing valves are attached to the hydraulic pressure supply pipes, respectively. The wheel cylinder is coupled to the front pressure chamber via the first hydraulic pipe, and a coupling pipe for coupling a first hydraulic pipe and the hydraulic supply pipe is provided with the switching valve.

Abstract: A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoir 2 to a pressure chamber 6 is formed in a cylinder body 3 connected to the reservoir 2. A bypass 37 for bypassing the supply passage connecting the reservoir 2 and the pressure chamber 6 is formed and provided with a check valve system 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2. A valve case 38 and a covering member 32 constitute a cartridge 39, which accommodates a valve body 41 and an urging spring 42, so as to form a check valve system 34. The cartridge 39 is placed in a valve chamber 33 of the bypass 37.

Abstract: A master cylinder having at least one piston that pressurizes a hydraulic fluid when a stepping force on a brake pedal is transmitted thereto and sends the pressurized hydraulic fluid to at least a wheel cylinder. The piston includes a large diameter passage and a small diameter passage having a diameter smaller than that of the large diameter passage, and a valve body is fastened to the large diameter passage to control fluid communication between the large diameter passage and the small diameter passage, the valve body including a plunger coupling hole and a channel through which the hydraulic fluid communicates between the large diameter passage and the small diameter passage, wherein a plunger slidably passes the valve body through the plunger coupling hole and closes the channel of the valve body when the stepping force on the brake pedal is transmitted to the piston.

Abstract: A hydraulic brake system includes a piston that separates a first pressure chamber from a second pressure chamber of a cylinder bore. A valve within a piston bore is movable between three positions. In the first position, the first and second pressure chambers are in fluid communication with a low-pressure fluid supply; in the second position, the second pressure chamber is isolated from the first pressure chamber and the low-pressure fluid supply; in the third position, a high-pressure fluid supply is in fluid communication with the second pressure chamber, allowing high-pressure fluid to flow into the second pressure chamber. High pressure in the second pressure chamber moves the boost piston, applying boosted braking pressure to a vehicle brake. Pressure in the second chamber against a surface of the valve biases the valve toward the first position.

Abstract: A clutch peak torque limiter for regulating the flow rate of fluid between a clutch master cylinder and slave cylinder in a vehicle transmission, the valve having a non-return valve for allowing free flow of fluid from the clutch master cylinder to the clutch slave cylinder, a return orifice for allowing return flow of fluid from the slave cylinder to the master cylinder, and a pressure controlled valve in parallel with the non-return valve and return orifice for allowing flow of fluid between the slave cylinder and the master cylinder, the valve opening when the pressure on either side of the pressure controlled valve exceeds a predetermined level.

Abstract: A force amplifier comprising a housing is provided. The force amplifier includes a force assembly positioned in the housing. The force assembly comprises an input force component, an output force component, and an intermediate force component rigidly coupling the input force component to the output force component. An assist piston is positioned in the housing. The assist piston is coupled to the force assembly. A regulating piston is positioned in the housing. The regulating piston is coupled to the force assembly. The regulating piston controls the supply of a pressurized fluid acting on the assist piston.

Abstract: A hydraulic cylinder has a pressure chamber delimited on one side by a piston accommodated in a longitudinally displaceable manner in a cylinder housing, on the other side by a housing bottom of the cylinder housing, and radially outwards by a circumferential wall of the cylinder housing, wherein the pressure chamber can be acted upon by a pressure medium via a pressure connection provided at the housing bottom in order to displace the piston in the cylinder housing. An insertion part is inserted in the pressure connection and has a channel section which communicates with the pressure connection and, in the installed position of the hydraulic cylinder, extends essentially in the vertical direction and opens into the pressure chamber in the vicinity of the circumferential wall of the cylinder housing. As a result, a hydraulic cylinder is provided which is compact and is designed in a simple manner, and which can be deaerated in a simpler manner compared to the prior art.

Abstract: An object of the present invention is to make it possible to easily improve precision with which the valve body is seated on the valve seat of the check valve, and provide a master cylinder which can be easily manufactured and in which high precision is realized. In a master cylinder, a supply passage for supplying operating liquid from a reservoir 2 to a pressure chamber 6 is provided in a cylinder body 3 coupled with the reservoir 2. A bypass passage 37 for bypassing the supply passage and connecting the reservoir 2 and the pressure chamber 6 is further provided, and a check valve 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2 is disposed in the bypass passage 37. A valve case 38 containing a valve body 41 of the check valve 34 comprises a valve seat 40 which the valve body 41 is seated on and moves away from, and a cylindrical wall 45 for slidably guiding the valve body 41 which are integrally formed as a single member.

Abstract: A controller 20 includes an initial current value calculation unit 22 calculating an initial current value to open a normally open linear solenoid valve when a hydraulic pressure is shifted from a pressure reducing state or a pressure holding state to a pressure increasing state, a valve opening amount increasing unit 23 reducing the energization amount from the initial current value so that a valve opening amount of the normally open linear solenoid valve increases, an offsetting necessity determination unit 24 determining based on a predetermined condition whether or not the energization amount needs to be offset to an increase side when the valve opening amount increasing unit 23 reduces the energization amount, and an energization amount offsetting unit 25 offsetting at least once the energization amount to an increase side only for a predetermined time period when it is determined that such offsetting is necessary.

Abstract: A pump of an electronically controlled brake system. The pump includes a bore formed in a modulator block and connected with a suction port and a discharge port, a piston installed in the bore in a reciprocating movable manner and defining an inlet path therein, an inlet valve to open or close an exit-side end of the inlet path according to a position of the piston, and an outlet valve provided at one side of the bore, operations of the inlet and outlet valves being contrary to each other. The outlet valve includes a valve seat, a sleeve to surround the valve seat, an outlet ball interposed between the sleeve and the valve seat and used to open or close a path defined in the valve seat, and a valve cap provided at one side of the sleeve to isolate an interior from an exterior of the bore. One or more of the valve sheet, sleeve, and valve cap are formed by press-forming, to achieve improved assembly efficiency and reduced manufacturing costs.

Abstract: The present invention relates to a brake fluid valve assembly (12). Assembly (12) comprises a housing (14) defining an inner chamber (21). A first non-return valve (32) and a second non-return valve (33) are arranged in the chamber (21). The housing (14) defines an inlet (22) and outlets (23, 24). Assembly (12) also comprises feed port means (34) arranged to allow fluid to flow from the inlet (22) to the first non-return valve (32). The first non-return valve (32) is arranged to let fluid flow from a master cylinder (11) through the inlet (22) and through the outlets (23, 24) towards a caliper (1) to apply a brake. Return port means (50) are arranged to allow fluid to flow from the outlets (23, 24) to the second non-return valve (33). The second non-return valve (33) is arranged to let fluid flow from a caliper through the outlets (23, 24) and through the inlet (22) towards a master cylinder (11). The assembly also comprises a restrictor port (52) between the outlet and the second non-return valve.

Abstract: A linear or rotary positive displacement expander (10) is fed by compressed gas or vapour from a reservoir (11) by means of a fast acting pulsed flow control valve (12) actuated by a PWM microprocessor (13) which receives input data from the expander (10) and the reservoir (11) to determine the correct operation of the valve (12). By injecting single or multiple controlled volume pulses of gas into the expander (10), the need for additional pressure regulation between the reservoir (11) and the expander (10) is eliminated, and the expander can operate efficiently within its built-in pressure ratio capability whereby the gas or vapour is expanded to be as close as possible to ambient pressure at the outlet of the expander.

Abstract: In a hydraulic system for motor vehicles in particular, including a master cylinder, a slave cylinder, and a pressure medium line connecting them, an inexpensive pressure boost is achieved by the fact that the hydraulic system includes a pump having an inlet and an outlet and a valve which are situated between the master cylinder and the slave cylinder in the pressure medium line. The valve has a first valve position in which the master cylinder and the slave cylinder are directly interconnected and a second valve position in which the master cylinder and the slave cylinder are interconnected via a pump.

Abstract: A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoir 2 to a pressure chamber 6 is formed in a cylinder body 3 connected to the reservoir 2. A bypass 37 for bypassing the supply passage connecting the reservoir 2 and the pressure chamber 6 is formed and provided with a check valve system 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2. A valve case 38 and a covering member 32 constitute a cartridge 39, which accommodates a valve body 41 and an urging spring 42, so as to form a check valve system 34. The cartridge 39 is placed in a valve chamber 33 of the bypass 37.

Abstract: A pressure intensifier for generating a relatively large force includes a plurality of pistons driven in advancing and retracting directions. The pressure intensifier includes a rod selectively drivable into a cavity to amplify the force acting on one of the pistons. A valve limits fluid flow to control the rate of movement of one of the pistons.

Abstract: The present invention includes a piston valve for charging and discharging a first fluid chamber. The piston valve includes a piston shaft and a ring comprising a seal element. The piston shaft has a first end and a second end with the first end including a counter bore having at least one vent. The ring is disposed within a cylinder and the seal element is disposed intermediate the piston shaft and the ring. The piston valve may be used for intensification purposes such as in a high pressure high temperature hydraulic cartridge.

Abstract: A pressure-limiting device in the hydraulic path for a clutch including at least one restrictor member having a central restrictor bore for pressure reduction and a cup-shaped retaining ring to which pressure is applied by a spring and the bottom of which has a central bore and, radially spaced therefrom, a plurality of radially spaced openings arranged on a reference circle. At least one of the restrictor member and the central restrictor bore is activatable when a predetermined volumetric flow rate of the fluid is exceeded during clutch engagement and the plurality of radially spaced openings is closable when a predetermined pressure drop is exceeded. The central restrictor bore can be activated independently of temperature because the surface area acting on the retaining ring is smaller in the unshifted state than during shifting, resulting with the temperature-dependent pressure losses caused by leakage between the retaining ring and housing being compensated for.

Abstract: Methods and systems for retaining hydraulic fluid in a hydraulic valve actuation system adapted to be installed on an internal combustion engine are disclosed. The system may include a hydraulic fluid supply connected by one or more passages to a fluid accumulator and a hydraulic valve actuator. The one or more passages may include a retaining portion elevated above portions of the fluid accumulator and/or the hydraulic valve actuator. The retaining portion may include an air vent and thus prevent back flow of all the fluid in the accumulator and/or hydraulic valve actuator to the fluid supply during periods that the engine is shut off. Retention of hydraulic fluid in the system may be further enhanced during engine shut off by selectively controlling the release of hydraulic fluid from the hydraulic valve actuator during the engine shut off process.

Abstract: A master cylinder suitable for a vehicle braking system has an unusual capability to supply quantities of fluid and fluid pressures at its output in differentiated manner in dependence on the braking stage, preventing long transitory stages between an approach stage and an actual braking stage. The cylinder comprises a cylinder body having a first chamber and a second chamber provided inside. The first chamber is in operative communication with at least one braking member and houses a first piston. The second chamber, which has larger transverse dimensions than the first chamber, is in operative communication with the first chamber and houses a second piston. Ducts are provided and put the first chamber and the second chamber into communication during the approach stage. The ducts house a low-pressure valve which is open during the approach stage and closed during the actual braking stage.

Abstract: An adjusting device for a tool includes a body with two ends and a fluid filled passageway, which extends between the ends, one end of the body cooperates with a work piece. An actuating member is movably connected to one end of the body, communicates with the fluid in the passageway, and has a surface, which cooperates with the work piece. Another actuating member is movably connected to the other end of the body and communicates with the fluid, and moves the fluid against the first actuating member to extend it. The fluid is locked against the first actuating member so that it retains the work piece in the body end.

Abstract: A choke valve of the clutch release cylinder wherein the actuating oil is slowly discharged when the clutch pedal is released, and when the clutch pedal is depressed, resistance to the actuating oil is minimized for the actuating oil to be swiftly and smoothly supplied to the clutch release cylinder, thereby improving the responsiveness of the clutch and preventing occurrences of noise and vibration when the clutch is in operation.

Abstract: A double-acting pressure intensifying cylinder and method, wherein a first cylinder a second cylinder are connected via an operation chamber in series. The first fluid chamber is provided with a first piston and the second fluid chamber is provided with a second piston. In an operation chamber, a rod is slidably inserted. The first fluid chamber has a first fluid supply port and an air port, the second fluid chamber has a third fluid supply port and a fourth fluid supply port, the operation chamber has a second fluid supply port. A check valve is provided wherein the series connected first and second cylinders at a position closer to the second cylinder than to the second fluid supply port in the operation chamber and makes it possible for a fluid such as a hydraulic fluid to flow only in one direction from the operation chamber to the second cylinder.