Abstract: A two-stage brake valve includes a stepped valve bore and pressure piston defining a first stage with a large effective area and a second stage with a smaller effective area. The two stages become effective in succession so that, initially the first stage is used to fill a system and then, following a transitional phase, the second stage generates an operating pressure. A relief channel communicates the pressure chamber of the first stage with a reservoir. A relief valve closes the relief channel in response to an excess pressure generated by operation of the second stage.

Abstract: The master cylinder (10) with externally adjusted secondary compensation comprises a tandem master cylinder (10) having primary and secondary piston assemblies (20, 30) disposed within a stepped bore (12). The portion of the bore containing the secondary piston assembly (30) has an enlarged diameter bore section (14) such that an end member (50) may be threadedly received within a bore opening (13) of the master cylinder (10). The end member (50) includes a longitudinal portion (55) having therein at least one outlet opening (60) and one compensation opening (58), each opening (58, 60) communicating with an interior opening (56) receiving slidably the secondary piston assembly (30) and a resilient spring (34) seated at one end of the interior opening (56) and biasing the secondary piston assembly (30).

Abstract: In order to reduce the number of component parts required for a master cylinder incorporated in a hydraulic brake system and steering brake system which is composed of two master cylinders interconnected through a compensating line, it is suggested by the present invention that the compensating line (60) be connected to a compensating chamber (22) adjacent to the pressure chamber (21), and that a valve assembly isolating the pressure chamber (21) from the compensating chamber (22) be formed by a sealing cup (7) arranged on an operating piston (3) that is actuatable by the master cylinder piston (2).

Abstract: A tandem type master cylinder is disclosed having a housing with a through-bore defining an intermediate portion and opposed end portions. The diameter of each end portion is larger than the diameter of the intermediate portion, and the junctures between the end portions and the intermediate portion define step parts within the housing. Seal assemblies are positioned within the housing at the step junctures formed by the intermediate portion and the end portions and are retained in position by a plug secured within each end portion. Primary and Secondary pistons are disposed for guided movement along the intermediate portion of the housing, and return springs are provided within the housing for urging each piston to its initial rest position.

Abstract: There is disclosed a liquid-operated booster having a jump-up function, in which the production of an internal pressure in a reaction force chamber in accordance with a reduction of the volume of the reaction force chamber is prevented. To achieve this, a mechanism for relieving the reduction of the volume of the reaction force chamber due to a relative movement of a piston and an input member toward each other is provided at a position facing the reaction force chamber. Most preferably, this relieving mechanism is constituted by a movable small piston provided at the side of an operating input.

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: The tandem master cylinder comprises, in a bore, a primary piston defining with a secondary piston a primary chamber, the secondary piston defining with the bottom of the bore a secondary chamber, the primary and secondary chambers having respectively primary and secondary outlet orifices, the primary and secondary chambers being respectively associated with primary and secondary expansion holes, able to be closed respectively by the primary and secondary pistons.The method for adjusting the lost motion of the secondary piston comprises the following steps:placing the pistons and springs in the boreleaving the primary piston in contact with its rest stopmoving the secondary piston until it closes the secondary expansion holedetecting the closure of the secondary expansion holemoving the secondary piston until the secondary expansion hole just reopensdetecting the reopeing of the expansion holesetting the maximum separation.

Abstract: In a veneer stacking system, a sensing device for sensing the incoming veneer sheets and computer determining from the information of the sensing device the stack on which the sheets are to be deposited. Knock-off shoes are positioned above the path of incoming veneer sheets. Multiple hydraulic cylinders connected into a hydraulic control system controls movement of the shoes. The multiple cylinders are simultaneously actuated by master cylinders which in turn are simultaneously actuated by a computer controlled mover piston. Air leaked into the hydraulic system is bled off by bleed orifices in the master cylinders communicating with a hydraulic fluid reservoir whereby air rises in the system up through the orifices and into the reservoir.

Abstract: A clutch master assembly made of plastic material for an automotive vehicle. The assembly a plastic cylinder housing (1) and a piston (2) and a plastic bushing (3). The plastic bushing is arranged to allow it to be screwed in by means of a thread portion (4) which is located in the housing. By the screwing-in of the bushing a grooved disc (5) and a grooved cup (6) are secured in the assembly. The grooved cup is furnished with knobs (21, 22, 23) which exert a force in axial direction on the arrangement consisting of the grooved cup (6) and the grooved disc (5). The piston-side enlarged end of the piston rod (31, 104) is secured within the piston (2, 103) by a back injection.

Abstract: A preassembled, prefilled hydraulic actuator apparatus for a motor vehicle clutch and adapted for connection to a non-integral fluid reservoir. The apparatus comprises a master cylinder having a supply inlet and a working pressure outlet, a slave cylinder having an inlet, a working pressure conduit interconnecting the outlet of the master cylinder and the inlet of the slave cylinder, and a low-pressure supply conduit for connection to a reservoir. In one embodiment, the supply conduit is connected at one end to the master cylinder inlet and the free end of the supply conduit is sealed by a bung partition, a piercing coupling is provided on the free end of the supply conduit, and the coupling is connected to an outlet fitting on a prefilled reservoir which may also serve as the hydraulic fluid source for the brake system of the vehicle.

Abstract: In a master cylinder for use in various braking devices of an automatic vehicle and the like, a cylinder housing is constituted by a body having an opening at one end thereof and by a cap which is coupled with the body to close the opening. A piston is inserted through the cap and is freely slidably arranged inside the cylinder housing and is guided by a piston guide or a sleeve having a path which is in communication with an external fluid path. The master cylinder has a single groove or a plurality of grooves with a micro-sized depth defined in the surface of the piston guide where it engages the cylinder housing between the external fluid path and a pressure chamber defined by the master cylinder and piston. The master cylinder also has a tapered portion provided on the inner surface of the cylinder housing, and another tapered portion is provided on the end of the sleeve.

Abstract: In a master cylinder, a sleeve for guiding the piston and a cap for forming a cylinder housing are connected with each other and integrally formed, and a primary piston and a secondary piston are coupled with via a retainer and thus integrally formed. Consequently, when the master cylinder is disassembled, the sleeve and the piston can be pulled out simultaneously, thereby allowing the simultaneous withdrawal of the secondary and primary pistons.

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 fine adjustment device for turning tool bits in the form of a pneumatic/hydraulic converter for converting of control signals into proportional actuating or adjusting forces with a combination of an oil pump and pneumatically controlled overflow valve, whose outlet pressure is adjustable with the help of control air.

Abstract: A method is suggested for assembling a tandem master cylinder and a vacuum brake booster of a hydraulic brake system for automotive vehicles. Air is injected via the pressure connection (19) of the pressure chamber (18) associated with the push-rod piston (2). Simultaneously, the push-rod piston (2) is moved in the direction pointing away from the brake pedal. The pressure increase in pressure chamber (18) is measured during the movement of the push-rod piston and, thus, during the movement of the central valve (6) accommodated in the push-rod piston. As soon as the closure member (5) of the central valve is seated on the valve seat (4), thus the central valve being closed, the air pressure will increase in the chamber (18). In the curve of the "pressure-against-central-valve-travel" diagram, which curve indicates the pressure increase, a trigger point is established which determines a measured distance on the abscissa of the diagram.

Abstract: The master cylinder (10) comprises a front or first housing part (12) which is generally U-shaped and a second or rear housing part (14) which is also generally U-shaped, the second housing part (14) being received within an end opening of the first housing part (12). The second housing part (14) has an end opening (16) opposite the first housing part (12) through which a first piston (18) is received. The first piston (18) and a second piston (22) are biased by respective resilient mechanisms (20, 24) disposed within a bore (26) defined by the parts (12, 14). Captured between the first and second housing parts (12, 14) are first and second interface members (80, 90) which have seals insert molded thereon. The first and second housing parts (12, 14) are held together by self-threading screws (100) such that a predetermined clamp load is imposed upon the interface members (80, 90). The master cylinder (10) has outlets (34, 36) all of which are oriented longitudinally toward the fron of the master cylinder.

Abstract: A dual chamber master cylinder has a center compensation valve for fluid compensation of the secondary pressurizing chamber, eliminating lip seal damage to the secondary pressurizing piston seal that can occur when a bypass port is provided in the wall of the secondary pressurizing chamber. Center compensation is accomplished through a passage connecting the secondary pressurizing chamber, under control of the compensation valve, to a common compensation chamber for both the primary and the secondary pressurizing chambers. In the preferred embodiment the common compensation chamber is the quick take-up chamber of the master cylinder. This provides quick take-up pressure to both pressurizing chambers upon initial master cylinder actuation.

Abstract: Improvement in an annular seal for use in a hydraulic actuator is obtained in accordance with the present invention, which annular seal is of the type including fitting holes to be inserted by projections formed in a piston guide and is adapted to be mounted between a piston guide sleeve and the piston guide, by the provision of annular projections extending in an annular shape and in the axial direction of the seal in the inner and outer circumferential portions with respect to the location of the fitting holes or in the circumferential area of the piston guide corresponding to that circumferential portions.

Abstract: A dual master cylinder for a vehicle brake system includes a housing having a housing bore with a open end and a closed end. The open end has a piston stop. Two pistons are reciprocably received in the housing bore and define therewith a first pressurizing chamber between the pistons and a second pressurizing chamber between the second piston and the housing bore closed end. Each piston has a piston cavity opening into the respective pressurizing chamber. A first locator member and a second locator member are respectively received in the pressurizing chambers and slidably mounted in the piston cavities of the respective pistons. The first locator member projects into engagement with the rear wall of the second piston and the second locator member projects into engagement with the housing to establish the pistons at respective normal rest positions enabling fluid communication through the port between the fluid reservoir and the respective chambers.

Abstract: The present invention relates to a tandem rotary master-cylinder for a vehicle brake circuit comprising a body (10;102) in which a first vane (20;114) is mounted for rotation in response to rotation of an input shaft (12;100) in order to generate pressure in a first working chamber (18;126) formed in the body (10;102) and delimited in part by the first vane (20;114).According to the invention the master-cylinder further comprises a second vane (30;120) rotatably mounted in the body (10;102) and delimiting with the first vane (20;114) the first working chamber (18;126) the second vane being rotatable in response to rotation of the first vane (20;114) to generate pressure in a second working chamber (62;128).A rotary master-cylinder with braking assistance is also described.

Abstract: A hydraulic pressure generator comprises a body in which is formed a bore, at least one piston mounted slidably in the bore, an annular sealing mechanism located in the bore, and the piston being slidable from a rest position during operation of the generator to cooperate with the sealing mechanism and divide the bore into a working chamber connectable by an output passage to a hydraulic actuator. A refill passage is connected to a source of hydraulic fluid. The output passage is formed in part between a first surface fixed in the bore and a second surface formed on a member mounted in the bore.

Abstract: A brake control valve has a valve bore, a piston member and an end member closing one end of the valve bore. One of the piston and end members has a projection and the other member has a corresponding blind bore for sealingly receiving the projection. The blind bore and the projection are spaced apart axially in the rest position of the piston. Upon axial movement of the piston the projection is sealingly received by the blind bore so that the effective working area of piston is reduced. By means of appropriate channels and grooves the chamber surrounding the projection is connected to reservoir.

Abstract: A master cylinder in which a sleeve is provided inside a cylinder main body to define a first pressure chamber in cooperation with primary and secondary pistons. A plurality of through-holes adapted to communicate with an outlet port are disposed in the sleeve in such a manner as to be longitudinally spaced away from each other. positioning means is provided between the sleeve and the cylinder main body for positioning the sleeve with respect to the circumferential direction relative to the cylinder main body. The sleeve is positioned relative to the cylinder main body in such a manner that at least one of the plurality of through-holes adapted to establish communication between the outlet port and the first pressure chamber when the pistons are at their rearmost positions is located to face the top portion of the circumferential wall of the cylinder main body.

Abstract: A master cylinder having pistons sliding through high pressure lip seals during operation. When the pistons are at rest during release, the seals are in an open position relative to the pistons sufficient to permit the passage of fluid therepast for compensation. The open positions are attained by providing piston portions of smaller diameter than the high pressure seals. These piston portions may be at least parts of piston beveled edge surfaces, or such edge surfaces in conjunction with notches or grooves which are of smaller diameter than the high pressure lip seals. The notches or grooves may extend circumferentially completely around the pistons, or may be arcuately extending circumferentially spaced notches or grooves.

Abstract: A valve for an automotive brake master cylinder piston is disposed at the end of forward stroke of the brake master cylinder piston in a passage defined along the axis of the master cylinder piston and communicating mutually an oil reservoir and an oil outlet, and is adapted to close and open the passage when abutting upon the departing from a side wall surface of the end of forward stoke of the master cylinder piston in accordance with a forward stroke motion and a return stroke motion of the master cylinder piston.

Abstract: An apparatus for the fine radial adjustment of a turning tool of a rotating cutter head with a first converter for converting a low pneumatic control pressure into a fluid pressure and with a further pressure converter for converting the intermediate pressure into a high working pressure for acting upon an adjusting medium, adjusts a turning tool. The first converter is stationary outside of the rotating head and is connected to the second converter, which is disposed in the rotating head, over a connection of conduits providing a rotary transmission for pressure transformation. The intermediate pressure is set higher than the control pressure, but lower than the adjusting pressure for unloading the rotary transmission.

Abstract: A hydraulic master cylinder formed by telescopically fastening together a pair of cylinder housings to form a cylinder. A piston in the cylinder is operative to transfer hydraulic fluid to a slave cylinder connected to the master cylinder. The pressure or power stroke of the piston is effected by exerting a pull on the piston by a pull cable attached to one side of the piston. A body, attached to one of the cylinder housing, provides a reservoir for hydraulic fluids. A cap on the reservoir closes a fluid filling opening. Expansion bellows in the reservoir accommodates changes in the fluid level in the reservoir as the piston is being reciprocated. The bellows is connected to the cap so as to be removed as a unit with the cap when the reservoir is being filled.

Abstract: A hydraulic master cylinder assembly of the type including a reservoir in which a diaphragm is disposed to divide the reservoir chamber into a hydraulic fluid chamber outside of the diaphragm and in communication with the pressure chamber of the master cylinder and a gas chamber within the diaphragm. The diaphragm is generally tubular with an open end and a closed end, and in a cross section transverse to the central axis of the diaphragm, includes a plurality of radially extending arms arranged about the central axis of the diaphragm and each including a pair of side walls defining therebetween a portion of the volume of the gas chamber. The diaphragm is movable between an expanded condition in which it assumes a substantially circular configuration in cross section and a collapsed condition in which each of the pairs of side walls of the arms are collapsed with respect to each other to reduce the volume of the chamber.

Abstract: A fastener driving tool for driving remotely located fasteners through preformed openings in a structure. The tool (10) comprises a housing (12) having a pneumatic-hydraulic intensifier (14) mounted thereon and a remotely located second hydraulic cylinder assembly (20) attached to the housing (12) by means of an extension tube (110). Pressurized air is provided to the tool (10) through a cartridge regulator (36) that is controlled by a trigger assembly (41). A pneumatic piston (72), connected to a first hydraulic piston (76) by a piston rod (80), moves from a first position located away from a nose portion (66) to a second position located toward a nose portion (66). The pressurizing valve (56) admits air to the pneumatic piston (72) to cause the first hydraulic piston (76) to move to the second position, thereby pressurizing hydraulic fluid (92) and causing the second hydraulic piston (102) to extend from the second cylinder housing (104).

Abstract: A replaceable cartridge assembly for master cylinder having a housing with a longitudinal bore and an oil inlet connected to the longitudinal bore. The assembly includes a cylinder removably mounted in the longitudinal bore, a pair of seal rings mounted on the cylinder and located on each side of the oil inlet, an axial bore in the cylinder having a fluid outlet at one end connected to the brake system, and a pair of ports connecting the space between the seal rings to the axial bore in the cylinder. A piston in the cylinder has a cup seal around the outside and an O-ring seal spaced from the cup seal. A collar in the end of the axial bore in the cylinder retains the piston in the bore while a spring in the axial bore in the cylinder biases the piston away from the end of the cylinder.

Abstract: A tandem master cylinder with a booster used for a hydraulic actuator such as an automotive brake system. The master cylinder has a first and a second independently movable presser piston disposed in tandem in a first housing such that the presser pistons and the first housing define a first and a second pressure chamber. The booster has a first power piston advanced by a fluid pressure in a first power chamber formed in a second housing, to advance the first presser piston. The booster has a valve operable due to a relative movement between the first power piston, and an operating member for operating said booster, whereby the fluid pressure in the first power chamber is controlled according to an operating force applied to the operating member.

Abstract: A hydraulic master cylinder piston carries a circumferential seal ring which allows recuperation flow valving. The floating seal has a reinforcing metal girdle which prevents radial expansion and axial crushing. The seal material resists extrusion and has an outer radius slightly greater than the radius of the circumferential girdle. A forward slotted bearing ring maintains the piston in alignment with the bore. During piston return, recuperation occurs through a path comprising the radial clearance between piston and floating seal ring and at least one slot or groove in the bearing ring. Upon full piston return, the seal is withdrawn from the master cylinder working chamber into a larger diameter bore communicating with the reservoir and thus allows relatively free make-up flow.

Abstract: A master cylinder for a vehicle braking system comprises a body (2) with a bore (3) open at the rear end of the body, a reservoir (4), a transverse port (17) in the body opening into the bore (3) and positioned rearwardly of the reservoir, and a passageway defined between the exterior of the body (2) and a sleeve (22) mounted thereon to communicate the transverse port (17) with a chamber (7) of the reservoir. in different disclosed embodiments the sleeve may be integral with the housing of a booster assembled with the master cylinder and an element may be interposed between the sleeve and the master cylinder body and be provided with a tubular extension interconnecting the reservoir with the passageway.

Abstract: An annular insert disposed at one end of a hydraulic cylinder and embedded in the material of the cylinder housing during molding of the housing. The insert has an internal groove in which a conventional retainer and abutment member in the form of an elastic spring steel split ring is engaged, whose function it is to act as a direct abutment preventing the piston disposed reciprocably in the cylinder from being pushed out of the open end of the cylinder, in some structures. In other structures the annular insert acts directly as a retaining member for the end of a sleeve installed in the cylinder housing, or indirectly through the intermediary of an end cap.

Abstract: A piston for acting on both a master cylinder and a fluid pressure booster is slidably disposed in a housing and defines a pressure buildup chamber communicating with a wheel brake actuating cylinder on one end and a power chamber on an opposite end. The cylinder has a plurality of axial slots defined in an outer peripheral surface thereof and communicating with inlet, supply, and outlet ports, there being seals disposed in the axial slots.

Abstract: In a hydraulic double-acting hydropneumatic pressure multiplying device suited for generating hydraulic pressure, and comprising a cylinder within which a piston is slidably mounted. The multiplying device is capable of generating hydraulic pressure in both the backward and forward strokes of the piston within the cylinder. For this purpose, the cylinder is closed at the bottom by a lower cap having an upwardly extending plunger received within a portion extending upwardly from the piston. The cylinder also provides an upper cap with a dome and the upwardly extending portion of the piston is reciprocating within this dome, thus defining between the portion of the piston and the dome a first pressure generating chamber, and within the upwardly extending portion of the piston and the plunger of the lower cap a second pressure generating chamber for obtaining hydraulic pressure in both of the strokes of the piston.

Abstract: A master cylinder has a piston slidably fitted in a stepped cylinder bore including a first pressure chamber connected through a coupling hole to a reservoir. When a fluid pressure in the first pressure chamber is increased to a predetermined level at the time the piston is moved forward, a second valve disposed in the coupling hole is opened to release a fluid pressure from the first pressure chamber into the reservoir. When a negative pressure is developed in the first pressure chamber as the piston is moved back, a first valve in the coupling hole is opened to supply a fluid from the reservoir into the first pressure chamber.

Abstract: A master cylinder of the quick-fill type has a pressure cylinder, a reservoir mounted thereon and a quick-fill chamber. The reservoir forms a compartment housing valve means controlling communication between the quick-fill chamber and reservoir.

Abstract: A master cylinder of the quick-fill type has an open-ended pressure cylinder closed by a closure member and a reservoir mounted on the cylinder. The closure member partially defines a quick-fill chamber in which slides a piston connected to a piston of the pressure cylinder. A valve controls communication between the quick-fill chamber and the reservoir.

Abstract: A tandem master cylinder for an automobile disclosed herein includes a cylinder body having a cylinder bore, a first and a second pistons slidable in the cylinder bore and axially apart from each other, a first and a second power chambers defined, independently from each other, in the cylinder bore by the first and second pistons, and an auxiliary reservoir formed integrally with the cylinder body at its upper side adjacent the first power chamber. The auxiliary reservoir has a first and second reservoir chambers separated from each other by a partition and both connected with a main reservoir. The first power chamber is connected with the first reservoir chamber through a pair of first vent and supply ports. The second power chamber is connected with the second reservoir chamber through an oil passage which is formed in the cylinder body and which uprises in the direction from the latter to the former.

Abstract: A tandem master cylinder for an automobile disclosed herein includes a cylinder body having a cylinder bore, a first and a second pistons slidable in the cylinder bore and axially apart from each other, a first and a second power chambers defined, independently from each other, in the cylinder bore by the first and second pistons, and an auxiliary reservoir formed integrally with the cylinder body at its upper side adjacent the first power chamber. The auxiliary reservoir has a first and second reservoir chambers separated from each other by a partition and both connected with a main reservoir. The first power chamber is connected with the first reservoir chamber through a pair of first vent and supply ports. The second power chamber is connected with the second reservoir chamber through an oil passage which is formed in the cylinder body and which uprises in the direction from the latter to the former.

Abstract: A combined hydropneumatic brake cylinder/air reservoir device having a hydraulic piston formed on the end of a push rod through which interconnected, different sized, pneumatic pistons operate to transmit the desired brake force. The hydraulic piston operates in a hydraulic cylinder having a slack adjuster piston arranged to supply or reduce the hydraulic fluid in the braking circuit in order to compensate for overtravel and undertravel of the pneumatic piston assembly due to brake shoe wear and brake shoe replacement respectively. The double-acting slack adjuster action results in the stroke of the pneumatic piston assembly being maintained constant to assure continued optimum operating efficiency.

Abstract: A fast-fill master cylinder (14) includes a housing (26) defining a bore (38) therein having a portion (y) thereof of substantially constant diameter. A primary piston (54) is movably received in the bore portion (y) and a secondary piston (56) is movably received in the remainder of the bore (38). The secondary piston (56) cooperates with the housing (26) to define a secondary variable-volume chamber (62). The primary piston (54) cooperates with the housing (26) and with the secondary piston (56) to define aprimary variable-volume chamber (58). The primary piston also cooperates with the housing to define a constant-volume recess (84) circumscribing the piston (54). An annular partition member (94) circumscribes the piston member (54) within the recess (84) to divide the recess (84) into a pair of variable-volume compartments (108, 110). A bore 120 communicates the one compartment (110) with the primary chamber (58).

Abstract: An automotive tandem type master cylinder comprising a cylinder body mounted in a frontwardly upwardly inclined manner for increasing the effective engine room space under the cylinder body, and an oil reservoir disposed at rearward, or lower position on the cylinder body for avoiding an increase in height of the hood. An oil passage is formed in the cylinder body in a rearwardly upwardly inclined manner for eliminating air bubbles in working fluid, and a mounting flange projects at the rear end of the cylinder body perpendicularly to the cylinder axis, whereby the cylinder body can be made easily and be shortened in its overall length.

Abstract: A compensation control and blow-off valve unit in a quick take-up master cylinder. In one embodiment, a stamped valve body forms a valve member within a valve chamber which permits compensation flow from the master cylinder reservoir to the pressurizing chambers. It has an O-ring seal controlling a passage from the valve chamber to the reservoir which opens the passage at a predetermined quick take-up pressure to return fluid to the reservoir. Other embodiments use an umbrella valve or a spring biased ball check valve. The valve housing in some embodiments also retains the reservoir housing in sealed position on the master cylinder housing.

Abstract: A master cylinder includes a sleeve (31) which defines fixed positions for a pair of seals (30, 32). A pair of pistons (36, 38) cooperate with the seals (30, 32) to form pressure chambers (40, 42) which communicate fluid pressure to brake circuits during braking. A bearing member (44) cooperates with one (36) of the pistons to define an auxiliary pressure chamber (50) and the bearing member (44) is provided with an additional passage (140) for communicating fluid into and out of the auxiliary pressure chamber as well as an end (46) directing movement of the one piston (36).

Abstract: A master cylinder includes a housing (22) with a bore (24) for receiving a pair of pistons (36, 38). The housing defines a reservoir (28) with an outer wall (26). The housing also defines at least one outlet passage (62, 66) communicating fluid from the bore (24) to a brake assembly (16). The outlet passage (62, 66) is partially defined by a boss (60) formed integrally with the housing (22) and the boss (60) cooperates substantially with the outer wall (26) to separate the reservoir (28) into a pair of cavities (84, 86).

Abstract: According to the invention, the communication between the supply orifice (40,41) and the corresponding pressure chambers (38,39) of the master-cylinder (11) is tested while the stop (25) defining the rest position of the piston (15) of the servo is being displaced, and this stop (25) is finally immobilized by crimping when the correct position of the stop has thus been found.

Abstract: A master cylinder assembly has a low pressure, high volume displacement quick take-up chamber and a high pressure, low volume displacement pressurizing chamber formed by a stepped bore and a stepped piston. A compensation control and blow-off valve unit has a peripheral lip seal type valve providing compensation flow on brake release but preventing flow from the quick take-up chamber during brake apply. A normally closed check valve can open to provide communication between the quick take-up pressurizing chamber and the fluid reservoir. When the pressurizing cup for the high pressure chamber closes its compensation port, the check valve is subjected to the pressure in the quick take-up pressurizing chamber. Initial fluid flow is obtained from the quick take-up chamber past the pressurizing cup into the high pressure chamber.

Abstract: A brake or clutch master cylinder has a slightly stepped bore with angularly equispaced grooves extending from the large diameter step into the small diameter step across the seal of the piston in its rest position. The fluid reservoir communicates with a groove of the large diameter step via a radial port.