Abstract: A master cylinder (10) for a hydraulic vehicle braking system comprises a housing (12) which has a bore (14) extending along a longitudinal axis (A), whose one end is closed by an end wall associated with the housing (12) of the master cylinder (10) and whose other opposite end is sealingly closed by a closure element (16). In the bore (14) adjacent to the closure element (16) a piston (18) is accommodated sealingly and axially movable which can be actuated through same, which has a central valve (20) which enables a fluid connection between a fluid reservoir and a pressure chamber (28) which is defined in the bore (14) by the end wall and the piston (18). When the piston (18) is not actuated, the central valve (20) is held in the open position by means of an abutment member (transverse pin 34) acting on the closure element (16).

Abstract: A master cylinder (12) for use in a brake system. The master cylinder (14) has a housing (22) with a bore (20) therein connected by a radial port (28) and an axial port with a reservoir (32) and to the brake system through first (34) and second (36) outlet ports. First (42) and second (44) pistons located in the bore (20) are separated by a first resilient means (46) to define a first chamber (50) while the second piston (44) is separated from the bottom (21) of the bore (20) by a second resilient means (48) to define a second chamber (52). The first and second resilient means (46,48) each include a first spring (90) which is caged between a first retainer (94) and a second retainer (96) by a linkage member (98) and a second spring (92). The linkage member (98) has a head (126) which engages the first retainer (94) and an end (128) which engages the second retainer (96) to hold the first spring (90) between the first (94) and second (96) retainers.

Abstract: A boosted braking device having a master cylinder and a pneumatic booster wherein the force for actuating the master cylinder is derived from a combination of an input force and a boost force of the booster. A main hydraulic piston of the master cylinder has a holler cylinder for receiving the input force. A secondary hydraulic piston located within the holler cylinder of the main hydraulic piston receives a hydraulic reaction force to impart an increasing braking force corresponding to an input force applied over an entire travel of a brake pedal.

Abstract: A manually operated in-line secondary master cylinder can be configured for use with any hydraulic system which accommodates multiple manual input forces, and which requires the secondary input device to operate independently of the primary input device. The secondary master cylinder can be placed directly in a primary system operating pressure line, where it has no effect on system operation until it is actuated. Unlike a conventional master cylinder, the device draws a very small amount of charging fluid directly from the primary system line due to its use of a split piston, free backflow and volume displacement approach.

Abstract: An improved compensation piston arrangement for use with a dual circuit master cylinder having a single service piston for simultaneously pressurizing a first fluid chamber and a second fluid chamber, wherein the compensation piston arrangement provides for pressure balancing between the first fluid chamber and the second fluid chamber to compensate for minor normal differences between the first and second fluid chamber. The compensation piston arrangement includes a movable compensation piston slidably disposed within a bore of a compensation housing, wherein the housing defines a pair of end stops positioned on opposing sides of the compensation piston. The bore is in fluid communication with the fluid chambers such that the pressure within the first fluid chamber acts on a first side of the compensation piston, and the pressure within the second fluid chamber acts on a second end of the compensation piston which is opposite the first end.

Abstract: A brake master cylinder with a plunger piston is acted upon by a brake linkage. A floating piston is arranged between two working spaces and separates the first and the second working space fluidically from one another. Each of the two working spaces opens into a main brake circuit, and the floating piston is axially movable in the brake master cylinder. A sleeve is axially movable in the brake master cylinder and is provided at least between the floating piston and the wall of the brake master cylinder. The sleeve and the wall of the brake master cylinder each have an opening which, in interaction, connect the first working space, formed by the floating piston and the plunger piston, to a displacement passage at least in the case of a movement of the floating piston into a first position in the direction of a brake actuation. With a movement of the floating piston beyond the first position, the sleeve is moved axially and separates the first working space from the displacement passage.

Abstract: A master cylinder includes a housing and a piston movable therein, which is sealed relative to a pressure chamber by way of a sealing element fixed on the housing. The pressure chamber is connectable to an unpressurized supply chamber by at least one transverse bore provided in the piston, wherein the transverse bore has a slot-shaped configuration and opens into at least one groove provided on the outer surface of the piston.

Abstract: A master cylinder (10) for a hydraulic brake system comprises a quickfill stage (28) which in the initial phase of an actuation of the master cylinder rapidly fills an associated brake system with hydraulic fluid upon a relatively short actuation travel. A housing (12) of the master cylinder (10) extends essentially along an axis (A) and comprises at least one pressure chamber (14) formed therein which is open at the actuation end of the master cylinder (10). A quickfill piston and a quickfill chamber of the quickfill stage (28) are essentially formed by a cup shaped component (30) which is guided on the acutation end of the master cylinder housing (12) in a telescopical and pressure chamber sealing manner. This solution can be manufactured economically and requires little installation space.

Abstract: A compliant master cylinder includes a primary piston and a secondary piston which are movable to provide fluid pressure to effect wheel braking in a vehicle. In addition, the master cylinder includes a compliant assembly which supplies conventional pedal feel and travel characteristics when the primary and secondary pistons are substantially immovable due to isolation the master cylinder from the wheel brakes. The compliant assembly includes a push rod piston that is movable against a selected amount of fluid pressure and spring force while the primary piston remains stationary. The fluid force is supplied by controlling the flow of fluid from behind the push rod piston through a flow restrictive orifice to a conventional fluid reservoir on the master cylinder assembly.

Abstract: A tandem master cylinder having a small-diameter cylinder formed on the same axis as a cylinder bore in a floating piston, communicating with a primary fluid pressure chamber and a secondary fluid pressure chamber. A small-diameter piston is movably inserted in the small-diameter cylinder, dividing the primary fluid pressure chamber from the secondary fluid pressure chamber. A small-diameter piston spring is mounted in the small-diameter cylinder, pressing the small-diameter piston toward the secondary fluid pressure chamber. A stop is provided in the small-diameter cylinder to stop the forward movement of the small-diameter piston in the small-diameter cylinder. An elastic member is disposed in an unbiased state between the small-diameter piston and a cylinder front end wall. The elastic member has an elastic force in a direction of compression which is greater than that of the small-diameter piston spring.

Abstract: A master cylinder includes a cylinder body including a cylinder portion, a piston fit into the cylinder portion so as to fluid-tightly divide the cylinder portion into a pressure chamber and a supply chamber, a connecting passage which is disposed in the piston and which connects the pressure chamber with the supply chamber, a valve mechanism which is mounted on the piston and which disconnects the connecting passage when the piston is moved for a predetermined distance and a restriction member installed in the connecting passage for restricting a flow of a fluid from the pressure chamber into the supply chamber when the piston is operated and allowing the flow of the fluid from the supply chamber into the pressure chamber when the piston is returned.

Abstract: A traction control low-restriction check valve for use in a compensating port master cylinder used with a traction control system and an antilock braking system. The check valve is a poppet valve mounted in a primary piston of the master cylinder. The popper valve is resiliently biased in a sealing position but allows brake fluid to be drawn by a traction control pump from a brake fluid reservoir against the resilient bias when the primary piston is not being translated to increase brake fluid pressure within the master cylinder.

Abstract: A brake master cylinder includes a shiftable seal that provides an apparatus for maximizing compensation fluid flow during minimal fluid draw conditions such as occur through automatic traction control brake intervention type operation. The shiftable seal moves forward to compress a low load spring during fluid draw from the master cylinder's high pressure chamber to open a compensation flow path between the seal and the piston.

Abstract: An hydraulic master cylinder has a cylinder body containing a valve of which a valve element cooperates with a valve seat carried by a piston, the piston performing a working movement, in use, to compress fluid in a pressure chamber of the body. The valve element and valve seat are relatively movable to permit opening and closing of the valve. A first abutment is arranged to set the retracted position of the piston and a second abutment, spaced from the first one in a direction opposite to the working piston movement, serves to hold the valve element in a desired open position when the piston is in its retracted position. The first and second abutments are both formed on a sleeve surrounding the piston.

Abstract: A dual master cylinder having a bore of uniform diameter extending through an open end thereof and slidably supporting therein a pair of tandem pistons defining a pair of pressurizing chambers. Fuel input is controlled by center-port poppet valves, and the relative disposition of inlet and outlet brake fluid passages are reversed compared to conventional master cylinders to facilitate master cylinder recession into a vacuum booster without requiring long, angled brake fluid passages and to require a shorter and lighter housing. The inlet and outlet passages are positioned so that seals do not slide over fuel passage ports during operation, eliminating seal wear caused thereby and allowing the ports to be larger, thus reducing back pressure and improving compensation when the pistons are returning to, or are in, an unstroked position.

Abstract: The present invention relates to a piston with a central valve, in particular for hydraulic boosters, the valve case (6) which is composed of a supporting insert (8) radially embraced by a valve seat (7). It is disadvantageous in some valve cases that sometimes the positive coupling between the two elements in axial direction is not sufficient. The present invention provides a remedy to this problem by using undercuts behind which the valve seat engages the supporting insert in both directions. In an advantageous improvement, the valve insert is of symmetrical design, and a sealing projection is shaped at the valve seat. The guidance of the valve tappet (19) is performed within the piston (1).

Abstract: A master brake cylinder for an anti-locking hydraulic brake system is provided, comprising a central valve provided in each piston. The central valve comprises a first valve and a second valve. The opening distance A of the first valve is smaller than the opening distance B of the second valve. The first valve is made of a metallic material while the closure member of the second valve is made of a soft-elastic material, such as a rubber ring 40. Being made of a hard material, the first valve can perform a pressure regulating function, involving, however, the risk that dirt particles contained in the pressure fluid, are forced into the valve ball and the valve seat, respectively, thereby preventing the valve from closing completely. In such an event, at least the closing function of the central valve is performed by the second valve. To a limited extent, the second valve also can take over a pressure control function.

Abstract: A piston arrangement for a master cylinder having a pin for linking a center compensation valve in primary and secondary pistons with a stop members. The primary and secondary each have a pin located in a blind bore which has a cylindrical body with a first semi-spherical head on a first end and a second semi-spherical head located on a second end. A valve return spring acts on a poppet assembly of each compensation valve to position a stem between the first and second semi-spherical heads to hold the pins in the primary and secondary pistons. When a piston return spring moves the primary and secondary pistons toward a rest position, the second semi-spherical heads are held stationary as the pins pivots about the first semi-spherical heads to act on stems and move poppets away from seats and communicate fluid from a source to pressurizing chambers associated with the primary and secondary pistons.

Abstract: Left and right two stage brake valves communicate fluid pressure to left and right brake mechanisms. Each brake valve has an inlet for receiving pressurized brake fluid from a pump, a reservoir port, a stepped bore and a stepped piston member comprising a larger diameter prefill piston and a smaller diameter high pressure piston. The stepped piston is movable away from a rest position to transfer fluid to the brake mechanism. The stepped bore and the stepped piston form a high volume prefill chamber and a high pressure chamber. The high pressure piston has a groove communicated with the brake mechanism, and the groove communicates with the inlet when the high pressure piston has moved a certain distance to transfer fluid from the high pressure chamber to the brake mechanism. The prefill piston has a sealing land and a second land on either side of a sealing ring which is slidable in the stepped bore.

Abstract: An actuating unit for a hydraulic brake system for automotive vehicles which operates by a precisely defined change-over pressure and with lost travel independent of the speed of actuation. The actuating unit includes a pneumatic brake power booster and a master brake cylinder connected downstream of the pneumatic brake power booster. The master brake cylinder contains a primary piston coupled with an annular piston of larger diameter. The annular piston confines a filling chamber which may be connected to the hydraulic pressure chamber. The annular piston is adapted to uncouple from the primary piston when the pressure acting on the annular piston reaches a predetermined amount. Thus, the displacement of the filling volume by the annular piston does not require an entire stroke of the master brake cylinder.

Abstract: A brake pressure control device (1) is described in which a low-pressure valve (19) and a high-pressure valve (29) are both actuatable by a brake pedal, resulting in a brake circuit (36) being connectible alternatively either to a reservoir (23) or to a pressure source (33, 34) by releasing or depressing the brake pedal. In order to allow control of the brake pressure by an electronic control, a valve piston (17) operating the high and low pressure valves (19, 29) is movable by an electromagnet (15) independently of the actuating position of the brake pedal, into a position in which the brake circuit (36) is connected to the reservoir (23) and the connection to the pressure source (33, 34) is closed.

Abstract: The master cylinder (30) includes primary and secondary pistons (42, 52) each of which has a center compensation valve member (44, 60). An abutment member or pin (38, 40) extends across a bore (36) of the master cylinder (30) adjacent ends of each of the pistons (42, 52) and the pins (38, 40) are each engaged by shafts (45, 64) of the spring biased valve members (44, 60) of the primary and secondary pistons (42, 52). An output rod (43) of a vacuum booster (41) to which the master cylinder (30) is attached disposes the primary piston (52) slightly spacedapart from the respective pin (40) in an at-rest position. The primary piston (52) includes a self-adjusting compensation center valve seat (70) located within the primary piston (52), the valve seat (70) sealingly and slidingly movable relative to the primary piston (52). The valve seat (70) extends through a rear opening (59) of the piston (52) to engage the respective pin (40).

Abstract: An actuating unit for hydraulic automotive vehicle brake systems, including a vacuum brake power booster, a master brake cylinder, and an operating element, configured to achieve a reduction of overall axial length and a simultaneous reduction of the weight and a relief of the booster housing from forces of reaction. The brake pedal (3) operating arm is interposed between the vacuum brake power booster (1) and the master brake cylinder engaging an axially extending member interconnecting a control valve piston and a master cylinder piston (2). The booster housing (10) and fluid reservoir (4) are mounted within the engine compartment while the master cylinder housing has a flange portion fixed to the splashwall and a main portion which projects out of the engine compartment through the splash wall, and into the passenger compartment. The hydraulic reaction forces are absorbed directly from the master cylinder housing into the splashwall rather than through the booster housing.

Abstract: A center-compensation master cylinder (10) has first (20) and second (30) pistons with center-compensation valve members (27, 37). The pistons (20, 30) have diametrically extending slots (22, 32) at central axial portions thereof through which extend pin members (53, 54) to effect opening of the valve members (27, 37) when the pistons (20, 30) are in at-rest positions. A first spring (29) extends between a head (24) of the first piston (20) and the second piston (30), and a second spring (39) extends between an end (15) of the bore 0 (I4) and the head (34) of the second piston (30). The first spring (29) is caged via a caging mechanism (60) ensuring that the first (20) and second (30) pistons will travel simultaneously when the center-compensation valve members (27,37) are closing. The caging mechanism (60) is adjustable to control accurately the location of the second piston (30 ) in an at-rest position.

Abstract: The present inventive relates to a master cylinder (1 ) with elastomeric central valves (20) which can be opened in opposition to a relatively high pressure in the pressure chambers (8 and 9) without damage. The sealing face (29) of the valve member (26) is in the form of a hollow cylinder protruding slightly from the broad head portion (24) of the valve pin (21). The valve member sealing face does not, as has been conventional practice, extend radially inwardly past the head portion (24) in the direction of the central bore (13) to avoid being drawn into the bore (13).

Abstract: A vacuum brake power booster is presented in which the vacuum control valve (81) is arranged parallel to the master cylinder (55). The housing (92) of the booster is used as a carrier element for actuating members, such as the brake pedal (60, 8) and the clutch pedal (11) as well as for other elements. A twin master cylinder is employed. A short overall axial length and a space-saving design of the assembly as a whole, enabling efficient incorporation of the overall assembly at the assembly line of the vehicle manufacturer, are achieved by the selection and arrangement of the components of the brake power booster and of the master cylinder, as well as of the actuating members.

Abstract: A setting method for minimizing the closure travel of a central valve in a master cylinder is proposed, wherein, after the assembly of all internal parts except the stop (10), the internal parts having a position which corresponds to the inoperative position, the distance (y) between that end of the axial extension (12) which is on the actuating side and a fixed point is measured and wherein then, in dependence upon the measured distance (y) a stop (10) is chosen such that the desired closure travel (x) between the closing body (13) and the valve seat (14) of the central valve is established. By means of said method the closure travel of the central valve (x) is exactly adjustable irrespective of the tolerances of other component parts or a preceding power booster.

Abstract: A caging arrangement for limiting the extension of springs in a bore. The caging arrangement includes cylindrical members which are connected to pistons in a master cylinder. The cylindrical members which are joined to the pistons and communicates the force of piston return springs to urge the pistons toward a rest positions while a valve return springs retained by the cylindrical members urges valves toward stops to control fluid communication between a reservoir and pressure chambers associated with the pistons.

Abstract: An arrangement and process for adjusting a supply valve closing in a tandem piston master cylinder is disclosed. The tandem piston master cylinder includes a piston stroked by engagement with an operating rod and a spaced floating piston driven by an interposed return spring, the floating piston captured by the rod engaged piston during the return stroke by a headed screw abutting a projection at the end of a bore within the screw head moves during relative movement between the pistons. Supply valves are opened and closed by the position of each piston. The piston relative positions are adjusted to achieve proper supply valve closing by rotation of the rod engaged piston while fixing the floating piston against rotation which rotates the screw thread which also slightly varies the precompression of the return spring. This adjustment selectively controls the point of closing of the supply valve associated with the floating piston relative the position of the rod operated piston.

Abstract: A cylinder-piston unit including a central valve having a valve shaft, on which two spring plates with a pre-stressed restoring spring are disposed. One of the spring plates is engaged from behind by a cross-sectional enlargement of the valve shaft which has a valve closing element. The cross-sectional enlargement is formed by a collar of the valve shaft. Another cross-sectional enlargement comprises a sleeve, which is longitudinally displaceably guided on the valve shaft. On the side remote from the restoring spring, the sleeve has an enlarged inner bore, with which the enlarged inner bore complementarily fits over a snap ring that engages the valve shaft. As a result, a form-locking connection is attained between the sleeve and the valve shaft that assumes that a preassembled valve component unit will be held together even if the snap ring breaks.

Abstract: A hydraulic braking system includes a master cylinder having a bore with an opening and a closed wall at opposite ends. At least one piston is slidably fitted in the bore and operatively connected to a brake pedal and at least one pressure chamber is defined in the bore by the piston and in communication with wheel cylinders of the vehicle. A normally open valve is associated with the piston so as to close a passage communicating between a reservoir and the pressure chamber when the piston is moved in response to the depression of the brake pedal. A hydraulic booster actuates the master cylinder in response to depression of the brake pedal, and an interrupting device interrupts the communication between the pressure chamber and the reservoir before the normally open valve closes the passage means and is interposed between the pressure chamber and the reservoir. Thereby, the idle stroke of previous master cylinders is eliminated.

Abstract: A dual master cylinder (10) for the braking system of a motor vehicle comprising a primary portion and a secondary portion (14) in which the high pressure chamber (56) of the secondary portion includes a check valve (62) mounted within a piston bore (64) in the secondary piston (44), the piston bore providing a fluid passage (70,96,66) between the high pressure chamber and the low pressure chamber (48) of the secondary portion, the check valve allowing hydraulic fluid to flow through the fluid passage during a rest mode or a release mode of the dual master cylinder, but preventing such flow during an apply mode. Prevents damage to elastomeric cup seal (52) when back-pressure is generated by ABS dus to the absence of a dilation port in the secondary portion, which is no longer required due to the presence of the check valve.

Abstract: An annular elastomeric seal, a piston utilizing the seal, and a fluid cylinder assembly utilizing the seal. The seal includes an axially forward portion defining a circumferentially inner and a circumferentially outer deflectable lip seal and an axially rearward portion defining a circumferentially inner and a circumferentially outer arcuate heel seal. When positioned in an annular groove in a piston and with the piston slidably received in the bore of a cylinder, the annular seal provides fluid pressure sealing at the deflectable lip seals, provides secondary fluid pressure sealing at the arcuate heel seals, provides air sealing at the arcuate heel seals, and functions at the arcuate heel seals to preclude the entry of contaminants into the sealing interfaces. The seal is especially effective when employed in a hydraulic pressure cylinder of the center feed type since it allows the usage of a single annular seal positioned in a singular annular groove in the piston.

Abstract: The actuator comprises a clutch pedal lever (12) which is pivotally connected to a support (17). The pedal is integral with a cylinder (18) having a piston (20) therein which is connected to a hollow pushrod (28). The pushrod is also pivotally connected to the mounting (17). Pivoting movement of the pedal (12) causes the cylinder (18) to move relative to the piston so that fluid within the cylinder will operate a slave cylinder (44). The clutch and pushrod have spaced axes of pivoting (13a, 14a) and the piston (20) is shaped to permit a degree of tilting to take place between the piston and the cylinder. The system also includes a reservoir which can communicate with the cylinder when the piston occupies a particular position in the cylinder.

Abstract: A dual master cylinder (10) for the braking system of a motor vehicle comprising a bore (18), a primary portion (12) and a secondary portion, in which the primary piston (16) comprises an outer piston (65) slidable in the bore (18), and a central piston (78) slidable in a piston bore (64) defined by the outer piston, the piston bore having a shoulder (72) engageable with an abutment face (98) on the central piston to define a check valve (62), the piston bore providing a fluid passage (70,96,68) between the high pressure chamber (30) and the low pressure chamber (22) of the primary portion, the check valve allowing hydraulic fluid to flow through the fluid passage during a rest mode or a release mode of the dual master cylinder, but preventing such flow during an apply mode. Prevents damage to elastomeric cup seal (26) when back pressure is generated by ABS due to the absence of a dilation port in the primary portion, which is no longer required due to the presence of the check valve.

Abstract: A dual brake circuit master cylinder with center compensation on the second circuit is provided. The master cylinder has a second piston mounted within a housing bore sealably separating a second reservoir passage from the second brake circuit passage when the pressure within the bore exposed to the second brake circuit passage exceeds the pressure within the bore exposed to the second reservoir passage. The second piston also has a compensating passage with an inclusive valve seat with an inserted compensating valve allowing fluid communication between the second reservoir and second brake circuit passages when the pressure in the second reservoir is greater than the pressure in the brake circuit. An auxiliary piston is provided to insure that the second compensating valve is retained to an open position when ever the second piston is in a retracted position and excessive pressure in the brake second circuit has acted to close the second compensating valve.

Abstract: In a hydraulic pressure control valve for use with a master cylinder, a valve chamber is formed at an attaching section of a valve body. An annular recess is formed in the valve body at a location of an end of the stepped bore, which opens to the valve chamber. A valve element is arranged within the valve chamber for movement therewithin. The valve element has a stud which extends to an interior of the master cylinder and which receives, from the piston within the master cylinder, such a force as to cause the valve element to fall down. An annular preventing element is formed separately from the valve element and the valve body. The preventing element is arranged between the valve element and the end of the stepped bore, which opens to the valve chamber. The preventing element substantially covers an annular end of the annular recess, which opens to the valve chamber, for preventing a seal element from coming out of the recess, which is arranged therewithin.

Abstract: A tandem master cylinder for hydraulic brake systems for automotive vehicles, with the brake systems comprising a brake pressure control means, in particular, an anti-locking control means. The tandem master cylinder has a push rod piston (7) and a floating piston (8), with each piston having a central valve. The valve closure member (13) of the central valve in the push rod piston (7) can be controlled both by a pin (16) directly or indirectly abutting the housing of the tandem master cylinder and by a pin (17) coupled to the floating piston.

Abstract: A tandem master cylinder (1) with central valves (12, 37) positioned in the secondary piston (15), separate from the latter at the end of the cylinder bore (2) and arranged with filter elements (27, 28, 48, 49) upstream of the central valves (12, 37) so as to protect the latter from dirt. In order to be able simultaneously to reduce the total overall axial length, hydraulic fluid flows radially through the filter elements (27, 49) which become effective in the event of a backflow of hydraulic fluid and said filter elements (27, 49) are positioned on the pedal side in respect of the second stop (14) of the secondary piston (15), respectively radially aside the closing spring (46) of the second central valve (37).

Abstract: A tandem master cylinder in which the primary piston and the secondary piston are configured in the shape of plunger pistons which are captivated to each other in the longitudinal bore of the cylinder housing. A cylindrical bushing is provided in the housing longitudinal bore and accommodates sealing cups sealing off the two pistons. The two valves which control hydraulic fluid flow are actuatable independently of each other.

Abstract: In order to shorten the overall axial length of a dual piston tandem master cylinder for hydraulic brake systems, the second piston thereof is anchored on the bottom of the longitudinal bore and the first piston is anchored on the second piston.

Abstract: A master cylinder is provided with an arrangement which prevents a valve from being held in a closed and inoperative position by residual pressure in the system. By preventing the valve from being held in the closed position, residual pressure can be released from the cylinder and prevent brake fluid pressure from disabling the brake system.

Abstract: A fluid pressure actuator according to the invention is suitable for use as a master cylinder for a vehicle brake or clutch system. The actuator includes a housing having a bore extending therethrough and at least a primary piston movably disposed within the bore and extending out of the housing through one end thereof. The other end of the bore is closed by a removable end cap. A pressure chamber is defined within the bore between the end cap and the piston. Preferably a cylindrical cartridge is located within the housing and that cartridge defines the bore with which the piston is in engagement. The cartridge is removable from the housing when the end cap is removed and this facilitates maintenance or repair of the master cylinder. A fast fill seal assembly may be included on the piston and the actuator preferably a double piston and pressure chamber assembly with a secondary piston being located between the primary piston and the end cap.

Abstract: A hydraulic braking system includes a tandem master cylinder having a bore with an opening and a closed wall at opposite ends thereof which formed in a housing, a first piston slidably fitted in the bore so as to define a first pressure chamber and a first fluid chamber therein and operatively connected to a brake pedal, a second piston slidably fitted in the bore so as to define a second fluid chamber adjacent to the first pressure chamber and a second pressure chamber and operatively connected to the first piston. A normally open valve communicates with each piston so as to close passages formed in the each pistons and communication between each fluid chambers and each pressure chambers, respectively, when each piston is moved in response to the depression of the brake pedal. A power source generates a hydraulic power pressure.

Abstract: A dual chamber master cylinder has a center compensating valve for bypass compensation of the secondary pressurizing chamber, eliminating lip seal damage to the secondary piston seal that can occur when a bypass port is provided in the wall of the secondary pressurizing chamber.

Abstract: A tandem master cylinder for hydraulic brake systems of automotive vehicles. The push-rod piston (29) and the floating piston (34) both are provided with a central valve. The central valve of the push-rod piston is coupled to the floating piston. The length of the bore (28) of the central valve in the push-rod piston (29) is dimensioned to allow the valve closure member (27) of the central valve in the push-rod piston to travel a distance within the bore of the central valve at least equal to the stroke of the floating piston (34).

Abstract: An oleopneumatic load intensifier apparatus for creating a rapid advance of a tool carrying piston rod followed by slow advance of the piston rod at an increased load. The apparatus has a master cylinder and an actuating cylinder that can assume different positions with respect to the master cylidner while maintaining fluid communication therewith. An enclosed hydraulic system is shared by the master and actuating cylinders. Pneumatic pressure actuates a piston within the master cylinder that causes a rapid advancement of a hydraulic fed piston within the actuating cylinder, causing a piston rod and a tool associated therewith to contact a workpiece. Pneumatic pressure then causes a piston and associated piston rod, located in the master cylinder, to increase the hydraulic pressure in the line to the hydraulic fed piston located within the actuating cylinder, thus, increasing the load delivered to the workpiece.

Abstract: A tandem master cylinder for a hydraulic brake unit with slip control. In the housing of the brake unit a primary piston pre-loaded by a first return spring and a secondary piston pre-loaded by a second return spring define a primary and a secondary pressure chamber within a longitudinal bore. The pressure chambers are connected to a fluid reservoir and are associated with a first and a second control valve which release or shut off a second connection between the pressure chambers and the fluid reservoir depending on an actuating force. In order to reduce the overall axial length of the tandem master cylinder, the control valves (10, 11) are arranged outside the pistons (6, 7) and are actuated linearly by the pistons (6, 7).

Abstract: A hydraulic cylinder having an internal groove in which is disposed a seal member peripherally engaging a seal-less reciprocable piston. In one form, the hydraulic cylinder is a master cylinder having a valved port in fluid communication with a source of fluid, opening and closing of the port being effected by a reciprocable plunger mounted on the end of the piston. An outlet port and a conduit places the chamber of the master cylinder in fluid communication with the chamber of the slave cylinder. In a slave cylinder version, a single port places the pressure chamber of the slave cylinder in communication with the master cylinder for introducing fluid and withdrawing fluid into and from the slave cylinder chamber, and thereby reciprocating the slave cylinder piston.

Abstract: A hydraulic braking system having an auxiliary piston disposed between an input piston and a presser piston, so as to define a first power chamber between the auxiliary and presser pistons, and a second power chamber between the input and auxiliary pistons. The presser piston cooperates with a housing to define a pressure chamber connected to a first braking arrangement. The first power chamber is connected to a second braking arrangement and supplied with a power pressure from an external hydraulic source through a control valve and the second power chamber. The system includes a connecting mechanism connecting the auxiliary and presser pistons such that the two pistons are normally placed in a spaced-apart state but are abuttable on each other.