Abstract: A master brake cylinder includes a unique mounting arrangement for securing thereof to a firewall of a vehicle and a particular porting arrangement. A cylinder sleeve includes a series of ports that cooperate with movement of the piston allowing for by-passing of the piston at one end position and then movement of the piston past the ports for brake actuation. Additionally a two stage pressure intensifier is provided that is in-line between a master brake cylinder and brake pistons. The intensifier also includes a by-pass position at one end of the movable piston having a differential area between a forward and a rear face of the piston.

Abstract: A piston assembly is provided for a human-powered vehicle. The piston assembly includes a main body and a primary seal. The main body is configured to be movable from a rest position to an actuated position along an actuation direction in a cylinder bore. The primary seal includes a primary seal body arranged on the main body. The primary seal body is made of a resin material. The primary seal body has a primary lip portion configured to be in contact with the cylinder bore in an arranged state where the piston assembly is arranged in the cylinder bore. The primary seal further includes a biasing part configured to be in contact with an outer circumferential surface of the main body to outwardly bias the primary lip portion of the primary seal body in the arranged state.

Abstract: A brake lever assembly includes a body, a seat and a pin. The body is connected to the seat and includes an outer surface which is engaged with an inner surface of the seat so that the body cannot rotate relative to the seat. The seat is connected to a brake lever and a handlebar. The body is connected to an adapter which is connected with a hydraulic oil pipe. A piston is located in the body and activated by the brake lever. The pin extends through the seat and the body to prevent the body from dropping from the receiving hole axially. The brake lever assembly is easily installed to the handlebar.

Abstract: An electronic hydraulic brake device includes: a pedal master to generate hydraulic pressure through pressurization of a pedal and including first and second master chambers; a reservoir including first and second reservoirs to store hydraulic fluid; an electric master to generate hydraulic pressure and including forward and backward chambers; a wheel cylinder to provide a braking force to front and rear wheels; a storage line connecting the pedal master and the reservoir to guide hydraulic fluid; a forward chamber line connecting the first master chamber, the forward chamber, and the wheel cylinder to guide hydraulic fluid; a backward chamber line connecting the second master chamber, the backward chamber, and the wheel cylinder to guide hydraulic fluid; and a connector selectively connecting the forward chamber line and the backward chamber line to guide hydraulic fluid.

Abstract: A vehicle includes a vehicle cabin, a storage chamber, and a partition wall separating the storage chamber from the vehicle cabin. The storage chamber is arranged on at least one side of the vehicle cabin in the vehicle front-rear direction. The partition wall has an opening and the storage chamber communicates with the vehicle cabin via the opening. A cover configured to open and close the opening is provided over the opening. A brake fluid pressure generation device is stored in the storage chamber. The brake fluid pressure generation device includes a reservoir tank in which hydraulic fluid is accumulated and is arranged at a position facing the opening.

Abstract: A hydraulic device is provided for a human powered vehicle. The hydraulic device includes a piston, a base member, and a hydraulic cylinder. The base member is made of a first non-metallic material. The hydraulic cylinder is provided to the base member and defines a cylinder bore. The hydraulic cylinder includes a main portion in which the piston is movably arranged. The main portion is made of a second non-metallic material that is different from the first non-metallic material.

Abstract: In order to offer an improved brake device without vacuum booster, in the case of which brake device the zero point of the cylinder piston remains as far as possible permanently within defined narrow tolerances and at the same time the impact noise is reliably reduced, it is proposed that the stop disk is elastically reversibly compressible in an axial direction over a defined compression travel and has the compression travel delimited, the delimitation being defined in a travel-controlled manner.

Abstract: A bicycle hydraulic device is basically provided with a base member, a piston, a guide rod and a guide rod seal ring. The base member includes a main body having a cylinder bore and a guide bore. The piston is movably disposed in the cylinder bore. The guide rod is coupled to the piston to move the piston. The guide rod is movably disposed in the guide bore. The guide rod seal ring is disposed on the guide rod and in sliding contact with the guide bore.

Abstract: A master cylinder device includes a reservoir tank, a master cylinder, a piston, and a pair of cup seals. The master cylinder includes a cylinder body having a cylinder chamber and a master port. The piston is inserted into the cylinder chamber, and has a relief port that communicates with the master port. The cup seals are provided on an inner circumference of the cylinder chamber, being positioned in front and rear of the master port, and seals a space between the inner circumference of the cylinder chamber and an outer circumference of the piston. The relief port is closed by the front cup seal, as the piston moves forward, to generate brake fluid pressure in a brake fluid in a hydraulic chamber. The relief port is tilted from a front side to a rear side, from the outer circumference toward an inner circumference of the piston.

Abstract: A vehicle is able to be set to operate in a factory mode (as opposed to a normal mode) in which certain features are disabled, such as an alarm system, a power liftgate, etc. This allows assembly workers to assemble, test, and calibrate the vehicle without various systems in the vehicle being undesirably activated. While in the factory mode, the vehicle can accomplish multiple ignition on/off cycles while being tested or driven between stations. A steering column and connected steering wheel are provided in the vehicle, and are situated between an instrument panel and a front seat. In response to the ignition completing an on/off cycle, a controller commands a motor to move the steering wheel and steering column to a predetermined position that is based on a visibility of the instrument panel relative to the steering wheel and steering column.

Abstract: A fluid container having at least one internal chamber for receiving a fluid, and having at least one connector for hydraulically connecting the internal chamber to a downstream hydraulic apparatus, wherein the connector at the end thereof toward the internal chamber has a mouth portion. In order to propose an improved fluid container by way of which high volumetric flows can also pass through the connector at high throughflow rates with low losses and reduced resistance, it is proposed that an escape value of the connector is provided so as to be larger than 0.82, and the mouth portion in relation to a container wall region that directly surrounds the mouth portion is at least in portions designed so as to be raised in the direction of the internal chamber.

Abstract: A control device for a bicycle, has a first body adapted to be attached to a bicycle handlebar, at least one control member of at least one bicycle component, and a second body, distinct from the first body, connected to the first body to increase a grip surface of the control device and/or to vary the relative position of the at least one control member with respect to the handlebar of the bicycle, so as to adapt the control device to the size of the cyclist's hand.

Abstract: A master cylinder device 38 for a rear wheel brake of a motorcycle includes a master cylinder 35 and a reserve tank 36. The cylinder 35 discharges brake fluid when a piston thereof is pushed by depression of a brake pedal 40. The reserve tank is integrally formed with a cylinder body 35a of the master cylinder 35. A contour 60 of a rear wheel side of the master cylinder device 38 extending continuously from a bottom end ? of the master cylinder body 35a in a vertical direction to an upper end ? of the reserve tank 36 in the vertical direction is linearly formed to be oriented obliquely rearward and upward in a vehicle side view.

Abstract: A bicycle operating device comprises a base member, a hydraulic cylinder, a piston, and a fluid passageway. The base member is configured to be mounted to a bicycle. The hydraulic cylinder is provided on the base member and includes a cylinder bore. The piston is movably provided in the cylinder bore. The cylinder bore and the piston define a hydraulic chamber. The fluid passageway is connected to the hydraulic chamber. The fluid passageway is provided inside the base member. The fluid passageway has a length longer than a stroke of the piston.

Abstract: Flexible sheathing for the protection of piston-cylinder units for disc brakes are provided. Such flexible sheathing may be arranged in a retracted condition wherein the piston is completely accommodated within the cylinder and in an extended condition wherein the piston is completely extracted from a caliper body defining the cylinder. Pistons incorporating such flexible sheathings and calipers incorporating such pistons are also provided.

Abstract: A control device for a bicycle, has a first body adapted to be attached to a bicycle handlebar, at least one control member of at least one bicycle component, and a second body, distinct from the first body, connected to the first body to increase a grip surface of the control device and/or to vary the relative position of the at least one control member with respect to the handlebar of the bicycle, so as to adapt the control device to the size of the cyclist's hand.

Abstract: A master cylinder includes: a cylinder housing; a piston which is movably disposed in the cylinder housing so as to form a pressure chamber and a hydraulic fluid supplying chamber; a sealing member which is interposed between the cylinder housing and the piston. The piston has a plurality of communication holes for connecting the pressure chamber and the hydraulic fluid supplying chamber, and the plurality of communication holes are formed on a slanted surface which is provided to an outer surface of the piston.

Abstract: A master cylinder includes: a cylinder housing; a piston which is movably disposed in the cylinder housing so as to form a pressure chamber and a hydraulic fluid supplying chamber; and a sealing member which is interposed between the cylinder housing and the piston. An indentation portion is provided on an outer circumferential surface of the piston, wherein a rear wall of the indentation portion is formed as a slanted surface. A plurality of first communication holes are formed on a bottom surface of the indentation portion and a second communication hole is formed on the rear wall of the indentation portion.

Abstract: A master cylinder for a hydraulic brake comprises a compensating chamber, a cylinder in which a piston is movably disposed, a pressure chamber disposed in the cylinder and connected to the compensating chamber through at least one connecting opening, and a gasket for interrupting the connection between the pressure chamber and the compensating chamber. The gasket seals the compensating chamber and the pressure chamber against the environment.

Abstract: A bicycle control device is basically provided with a mounting bracket, a hydraulic unit and a shift unit. The mounting bracket includes a handlebar clamp defining a handlebar mounting axis. The hydraulic unit is provided on the mounting bracket and includes a cylinder housing defining a cylinder bore, a hydraulic reservoir and a piston. The hydraulic reservoir is fluidly connected to the cylinder bore. The piston is movably disposed in the cylinder bore along a cylinder axis of the cylinder bore. The shift unit is provided on the mounting bracket and includes a wire take-up member pivotable about a take-up axis. The wire take-up member of the shift unit and the hydraulic reservoir are disposed between the handlebar mounting axis and the cylinder axis as viewed along a first direction parallel to the take-up axis of the wire take-up member.

Abstract: Disclosed herein is a master cylinder for a brake system. The master cylinder for a brake system comprises a cylinder body in which a bore is formed, at least one piston provided to be movable forward and backward in the bore, a hydraulic chamber pressurized by the piston, an oil port connected to a reservoir and configured to supply oil to the hydraulic chamber of the cylinder body, and a sealing member installed in the cylinder body and configured to block a flow of oil between the oil port and the hydraulic chamber according to a movement of the piston, wherein the piston includes a piston groove having an inclined surface in contact with the sealing member and a plurality of piston holes formed along an outer circumferential surface of the piston groove configured to communicate the oil port with the hydraulic chamber.

Abstract: A master cylinder apparatus includes: an input piston that can be moved forward by operating a brake operating member; a pressure piston that is provided in front of the input piston to be capable of moving relative to the input piston; and a stroke velocity ratio modification device that is capable of modifying a stroke velocity ratio, which is a ratio between a stroke velocity of the pressure piston and a stroke velocity of the input piston, in at least two stages while the input piston moves from a rear end portion position to a front end portion position, and that sets the stroke velocity ratio at 1 when an abnormality occurs—in the master cylinder apparatus.

Abstract: A brake master cylinder arrangement includes a housing with a cylindrical recess, a pressure piston moveable in the cylindrical recess along a longitudinal axis and guided in a sealing manner, and a reservoir for storing brake fluid that is fluidically connected via a fluid channel to the housing. The pressure piston and the housing enclose a pressure chamber that is connected to a fluid circuit of the brake system. Depending on the position of the associated pressure piston, the pressure chamber is either fluidically connected to the fluid reservoir or disconnected therefrom. In a region that axially spans the sealing arrangement in a starting position of the pressure piston, the outer circumferential surface of the pressure piston has profiling that provides a fluidic connection between the fluid reservoir and the pressure chamber.

Abstract: A device is described for receiving and dispensing hydraulic fluid, in particular for a hybrid or electric vehicle, having a cylinder, a piston, which is movable in the cylinder for receiving and dispensing hydraulic fluid, and a drive unit; a ramp mechanism being provided, having at least one ramp on which at least one rolling element rolls for moving the piston, the ramp mechanism being situated between a face of the piston and a face of a gearwheel driven by the drive unit.

Abstract: A primary piston composed of a skirt and an intermediate back wall having a rear face receiving the servobrake thrust rod and a forward face for the telescoping rod and the spring pushing the secondary piston. The front of the skirt has longitudinal grooves open in front and closed in the rear. The thickness of the skirt beneath the grooves and the part of the skirt between two successive grooves in the peripheral direction form a front face enabling the principal piston to push the secondary piston. The principal piston is made of a single piece of plastic material.

Abstract: An actuator system for hydraulic actuation of a clutch comprises a master cylinder with a master piston, a readjustment container for containing hydraulic fluid, a connection opening between the readjustment container and the master cylinder, where a degree of openness of the connection opening is dependent on the position of the master piston, and a hydraulic actuator to control a position of the master piston. In an actuator system, a control device for controlling the hydrostatic actuator is also provided, such that a speed of motion of the master piston is high while the connection opening is wide open, and low while the connection opening is open a little. In a method according to the disclosure, a position of the master piston is detected, and the actuator is controlled at different speeds depending on the position or the degree of openness.

Abstract: A master cylinder for a controlled brake system, including at least one piston which is displaceable in a housing and is sealed with respect to a pressure chamber by a sealing element arranged in an annular groove of the housing, which pressure chamber is connectable to an unpressurized supply chamber by control passages formed in the piston. The piston 46 is formed in at least two parts, including a main body and an annular control element, the control passages being provided in the control element.

Abstract: A hydraulic pump including a containment body (2) having inside a cylindrical cavity (3) provided with a conduit (4) communicating with a hydraulic actuator and capable of holding a fluid. A piston (5) is movable in the cylindrical cavity (3) and a reservoir (12) of the fluid is in fluid communication with the cylindrical cavity (3). An actuation device (6) connected to the piston (5) move the piston (5) within the cylindrical cavity (3) to operate the hydraulic actuator. The pump also comprises structure (13) for closing or opening the connection between the reservoir (12) and the cylindrical cavity (3). The reservoir (12) is substantially lined up with the cylindrical cavity (3) along an axis of longitudinal development (X) of same cylindrical cavity (3), so as to reduce the overall dimensions and the weight of the pump.

Abstract: Disclosed is an integrated braking system including a hydraulic piston cylinder unit that is operated by a brake pedal, a pressure medium storage unit that is connected to the hydraulic piston cylinder unit, a pressure generating unit that is driven by a motor, and has first and second hydraulic chambers that are divided by a piston movable within a housing, and a pressure control unit that transmits a pressure to a wheel unit from the hydraulic piston cylinder unit and the pressure generating unit. A hydraulic line directly connects the first hydraulic chamber and the pressure medium storage unit.

Abstract: A piston pump includes a piston assembly having at least one cross bore and a longitudinal bore corresponding to the at least one transverse bore, a cylinder, into which the piston assembly is guided in a longitudinally movable manner, and an inlet valve with a cage element, in which an inlet valve spring and an inlet valve sealing element are disposed, and a corresponding inlet valve seat, which is disposed on the piston assembly. Fluid flows through the longitudinal bore into a compression chamber via the inlet valve. A return spring is disposed in the compression chamber. The cage element has a resilient high-pressure sealing element that is configured to receive radially acting power components, and to effect a seal against a cylinder wall via a radial sealing surface, and in order to effect an axial seal against the piston assembly via an axial sealing surface.

Abstract: Master-cylinder seal housed in a groove around a piston has a core connected to three annular and concentric lips. The core rests against a side of the groove and has: a surface provided with an interior edge followed by a peripheral platter cut by at least one channel, and an exterior crown provided with a connection zone formed by an interruption in the crown and deformable due to pressure within the seal to recreate the crown's continuity and impermeability while facilitating purging the brake system when there is no pressure in the channel and the connection zone.

Abstract: The invention relates to an assembly including a pressure medium reservoir and a manually actuable master cylinder, in particular for a hydraulic motorcycle brake system, wherein the pressure medium reservoir is connected permanently to the master cylinder by at least one pressure medium connection, wherein the master cylinder has at least one pressure chamber, which can be connected to wheel brakes. According to the invention, provision is made for a protection device to be arranged in the region of the pressure medium connection, the device preventing air from penetrating into the pressure chamber and allowing air to escape in the direction of the pressure medium reservoir.

Abstract: A cup for a master cylinder coming into contact with its primary piston or its secondary piston and subjected to the pressure of the brake fluid of the primary chamber and of the secondary chamber. The cup has two large grooves bordered: by a rib between the heel and the first groove, by a rib between the first groove and the second groove, by a rib between the second groove and the small grooves, these ribs being in protrusion relative to the cylindrical surface of the heel in the mounted position of the cup in order to separate the heel from the surface of the piston and form, between the heel and the surface of the piston, a gap with a film of brake fluid. Master cylinder notably a tandem master cylinder fitted with such cups.

Abstract: A circumferential wall of a circumferential groove near a bottom section of a cylinder main body has an outer wall section extending from a bottom section of the circumferential groove in a radial direction of the cylinder main body, a stepped surface section extending from the outer wall section in a bottom direction of the cylinder main body, and an inner wall section having a flat surface section parallel to the radial direction of the cylinder main body and formed further inside in the radial direction of the cylinder main body than the stepped surface section. The inner wall section is formed at a position at which the center lip section first abuts the inner wall section prior to the outer wall section when the seal member moves toward the bottom section of the cylinder main body.

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 herein is a hydraulic master cylinder body having a bore defined at least in part by a bore wall, wherein the bore wall includes an opening for hydraulic fluid to be passed into the bore, and a piston assembly situated at least substantially in the bore, the assembly having a piston with a piston body and at least one cup seal situated substantially around the piston body, the cup seal situated adjacent to the bore wall so as to be in sealing engagement therewith, and a back-up ring that is situated about the piston body, wherein the back-up ring is positioned to at least partially cover a portion of the cup seal that is adjacent to the bore wall and to prevent at least a portion of the cup seal from contacting the bore wall and the opening for hydraulic fluid during piston actuation.

Abstract: A brake booster includes a housing, a retention cuff, and a spring. The housing defines a passage to an interior chamber. The retention cuff is positioned in the interior chamber about the passage. The spring engages the retention cuff in the interior chamber. The master cylinder arrangement includes a tube member and a brake fluid reservoir. The tube member includes a first end and a second end. The tube member extends through the passage and the retention cuff such that the first end of the tube member is exposed to the interior chamber of the brake booster. The brake fluid reservoir is in fluid communication with the tube member.

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 cup seal includes a base portion disposed on a cylinder bore opening portion side of a seal groove, an inner circumferential lip portion extended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston (plunger), and an outer circumferential lip portion extended from an outer circumferential side of the base portion toward the cylinder bore bottom portion and having an outer circumferential surface abutting against a seal groove bottom surface. The cup seal also includes an abutment surface and contact pressure adjustment surface.

Abstract: A sealing member for a piston slidably disposed within the cylinder bore of a hydraulic system includes a seal body having an outer sealing surface arranged to contact the cylinder bore and a glide ring at least partially disposed within the outer sealing surface of the seal body. The glide ring includes an outer surface and the outer sealing surface of the seal body includes at least one seal lip projecting beyond the outer surface of the glide ring.

Abstract: Master cylinder of a hydraulic braking circuit, particularly for a motor vehicle, comprising a piston (2) sliding axially in a body (4) comprising an annular lip seal (51) produced by molding, and comprising an internal, dynamic sealing lip (14) surrounding the piston and connected by a curved surface (36) to a planar rear face (30) comprising radial passages which are defined by blocks formed as projections on the rear face of the seal, these blocks being separated from the curved surface (36).

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 cup seal (21) of the invention includes an intermediate lip portion (21d), positioned between an inner lip portion (21b) and an outer lip portion (21c), provided in a base portion (21a). The intermediate lip portion (21d) is configured in such a way that first intermediate lip portions (21d1), communication passages (21d3), second intermediate lip portions (21d2), whose axial direction length is less than that of the first intermediate lip portions (21d1), and the communication passages (21d3), which have no lip portion, are cyclically disposed, in this order, in the peripheral direction. An easy elastic deformation portion of the base portion (21a) which elastically deforms easily is formed by the second intermediate lip portions (21d2) and communication passages (21d3) and, by the easy elastic deformation portion elastically deforming easily when supplying liquid, a flow passage with a larger passage area is formed.

Abstract: A master cylinder assembly for a hydraulic actuation system for a handlebar-steered vehicle. The master cylinder assembly generally includes a housing mountable to a frame member of the handlebar-steered vehicle and having a chamber including a fluid cavity with first and second fluid cavity regions. The first fluid cavity region is in fluid communication with the hydraulic actuation system. The housing includes discrete first and second housing portions. The first housing portion has first and second end portions. The first end portion of the first housing portion extends axially into the second fluid cavity region creating an annular gap radially outboard of the first end portion extending into the second fluid cavity region. The second end portion of the first housing portion is connected to the hydraulic actuation system. A piston assembly includes a piston slidably disposed within the fluid cavity.

Abstract: A master cylinder includes a cylinder bore, a first piston positioned within the cylinder bore, a second piston positioned within the bore and located forwardly of the first piston, a first pressure chamber within the cylinder bore and defined in part by a rear portion of the second piston and a forward portion of the first piston, a first pressure chamber seal extending radially outwardly from the rear portion of the second piston, a first reservoir inlet configured to provide fluid communication between a reservoir and the cylinder bore at a location forwardly of the first pressure chamber seal, and a first groove extending axially along the cylinder bore and positioned such that (i) when the second piston is in a released position, the first groove is located directly outwardly of the first pressure chamber seal and the reservoir is in fluid communication with the first pressure chamber through the first groove, and (ii) when the second piston is in an activated position, the first pressure chamber seal is

Abstract: A cup seal 21 includes a base portion 21a disposed on a cylinder bore opening portion side of a seal groove, and an inner lip portion 21b extended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston. In a state where the cup seal 21 is fitted into the seal groove and a plunger 19 is inserted into a cylinder bore 12, an abutting force maximum portion 21m where an abutting force against the plunger 19 becomes maximum within an inner circumferential surface of the cup seal 21 is provided on an end portion on the cylinder bore opening portion side of an inner circumferential surface part of the base portion 21a.

Abstract: A projection (21b4) provided at a tip portion of an inner lip portion (21b) of a first cup seal (21) comes in contact with a second side wall (20c) of a recessed portion (20) and a large axial force is exerted in the axial direction on a first tapered inner peripheral surface (21b1) of the first cup seal (21) from a rear side tapered surface (4b2) of a primary piston (4). This makes it possible to reliably hold the first cup seal (21) in the axial direction by utilizing the axial force. Therefore, the first cup seal (21) can be suppressed from moving in the axial direction. In particular, the projection (21b4) of the first cup seal (21) comes in contact with a tapered surface (20c?) of the second side wall (20c) to obtain a further increased axial force, and the first cup seal (21) can be held more reliably.

Abstract: An actuation device and a method for actuating a clutch, in particular for a hybrid drive, include a master cylinder having an interior separated by a master piston into master and slave oil chambers. The slave oil chamber is connected, via a valve in a first valve position, to a tank line leading to an oil reservoir and in a second valve position, to a pressure line of the oil reservoir. The master oil chamber is connected via a working line to an oil chamber of a slave cylinder and to a compensating tank via a compensating line as a function of the position of the master piston. The compensating tank has a compensating volume which has, at its highest point, an overflow which is connected to the tank line and in its first position the valve connects the slave oil chamber to the compensating tank via a return line.

Abstract: A cup seal 21 includes a base portion 21a disposed on a cylinder bore opening portion side of a seal groove, an inner circumferential lip portion 21b extended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston (plunger), and an outer circumferential lip portion 21c extended from an outer circumferential side of the base portion toward the cylinder bore bottom portion and having an outer circumferential surface abutting against a seal groove bottom surface.

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.