Abstract: A cartridge for selectively permitting flow from a master cylinder includes a cartridge body formed with an axial passage extending from a first end to a second end of the cartridge body. A cartridge stem is disposed in the axial passage and is movable in the axial passage between a closed position, in which the cartridge stem blocks flow between the first and second ends of the cartridge body, and an open position, in which the cartridge stem permits flow between the first and second ends of the cartridge body. A method for installing a master cylinder assembly, the master cylinder assembly including a master cylinder provided with a cartridge, in a fluid pressure control system is also disclosed.

Abstract: The invention relates to a bleed valve for a hydraulic circuit, comprising a piston capable of sliding in a bore formed in a body and actuating a shutter arranged between two sub-circuits and movable between a first position, in which it allows communication between the two sub-circuits, and a second position, in which it prevents this communication, the shutter being movable under the effect of an external mechanical action exerted by an actuating member. According to the invention, the sealing between the bore and the outside of the body is ensured by the actuating member, and the shutter is movable under the effect of a difference between the pressures which are exerted on its two faces.

Abstract: There is presented a method for assembling a tandem master cylinder and a vacuum brake power booster of a hydraulic brake system for automotive vehicles. Air is injected via the pressure connections (19, 36) of the pressure chambers (11, 18) associated with the pistons (2, 3). Simultaneously, the pistons (2, 3) are moved in the direction away from the brake pedal. The pressure increase in the pressure chamber (18) is measured during the movement of the pistons (2, 3) and thus during the movement of the central valve (14) accommodated in the floating piston (3). The air pressure in chamber (18) will rise as soon as the closing member (15) of the central valve (14) has moved to sit on the valve seat (16) and the central valve is closed thereby. A trigger point which determines a measured distance on the abscissa of the diagram is fixed in the curve of the diagram "Pressures as a function of the travel of the central valve", the said curve indicating the pressure increase.

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 hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately filled with hydraulic fluid, and the filled modular units are shipped unconnected to a user. Each modular unit is provided with a leakproof quick-connect connector member, through which filling of the modular unit may be effected, and which mates with a complementary leakproof quick-connect connector member of another modular unit, such that after installation on a utilization device, a motor vehicle for example, complementary connector members are reconnected, thus opening ports in each connector member placing each member in fluid communication with the other. Preferably, the two connector members are provided with a one-way locking arrangement preventing separation of the connector members after coupling.

Abstract: In a device for controlling the lift of a hydraulically operated valve comprising an actuating element which is pressure-loaded or spring-loaded in closing direction and which acts as the boundary of an actuating chamber in the valve cage, and further comprising a pressure-generating unit, the valve lift is made continuously adjustable, independent of the control times of the valve, by providing that a flying setting plunger be used, which is guided in a cylinder, and which bounds a pressure from the actuating chamber in the valve cage, and by further providing that the pressure-generating unit have a high pressure line controlled by a valve and leading into the pressure chamber, as well as a low pressure line controlled by another valve and leading into the actuating chamber, the setting plunger being pressed against a stop in the cylinder during maximum valve lift.

Abstract: A master cylinder apparatus for a vehicle is adapted to be attached to a bar type steering handle. This master cylinder apparatus comprises a master cylinder attached directly or via a bracket to the bar type steering handle, an operating level pivoted on the bracket or a lever bracket of the master cylinder by means of a support shaft, an adjust bolt provided thrustable forward and backward to the operating lever, and a push rod having one end abutting on the rear end of a piston in the master cylinder and the other end pivoted on a free end of the adjust bolt. The forward/backward thrusting movement of the adjust bolt alters the distance between the support shaft and the point of action of the operating lever to the push rod, thereby changing the lever ratio of the operating lever to provide the operational feeling desired by a rider.

Abstract: A method for topping off a reservoir chamber of a hydropneumatic pressure intensifier with oil, and the embodiment of such a hydropneumatic pressure intensifier, in which the reservoir chamber has a vent bore, which being usable as an overflow protection means as well is controlled by a flow control valve and is uncovered preferably by the reservoir piston in its outset position. In the event of improper aeration, the reservoir piston is thrust against a stop determining its extreme position, in a further feature of the invention a second vent bore can be uncovered by such movement.

Abstract: The bleed valve (22) especially for a hydraulic brake circuit, comprises a fluid reservoir (20), a hydraulic motor (26) and a mechanism for putting the fluid under pressure (24), and has a first port (42) connected to the motor (26) and to the mechanism (24) by way of a first conduit (62) and a second port (54) connected by way of a second conduit (60) to the reservoir (20) which is likewise connected to the inlet of the mechanism (24) by way of a third conduit (64), the first and second conduits (60,62) communicating with one another by way of the valve (22) during the initial bleeding phase of the hydraulic circuit, and no longer communicating from the moment when the fluid is first put under pressure. The valve (22) comprises a piston (36) capable of sliding in a bore (32,34) and keeping the shutter (44,42) of the valve open during the bleeding phase counter to a compressed spring (46 ).

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately filled with hydraulic fluid, and the filled modular units are shipped unconnected to a user. Each modular unit is provided with a leakproof quick-connect connector member, through which filling of the modular unit may be effected, and which mates with a complementary leakproof quick-connect connector member of another modular unit, such that after installation on a utilization device, a motor vehicle for example, complementary connector members are reconnected, thus opening ports in each connector member placing each member in fluid communication with the other. Preferably, the two connector members are provided with a one-way locking arrangement preventing separation of the connector members after coupling.

Abstract: A master cylinder for hydraulic use, particularly for brake systems for cars. At least two bleed screw openings mounted on the master cylinder body. The first bleed screw opening receives the bleed screw, the second bleed screw opening receives a plug screw.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately, but simultaneously, filled with hydraulic fluid after simultaneous evacuation of atmospheric air from the apparatus modular units and test of the integrity of the modular units, and the pre-tested and prefilled modular units are shipped unconnected to a user.

Abstract: A rotary piston pump assembly includes a rotary piston pump having a pump housing. First and second outlets lead fluid out of the pump housing. The fluid is returned into the pump housing through the first outlets and the first outlets are closed during a portion of the rotation of the pump.

Abstract: Apparatus for use in the bleeding of fluid systems, especially the hydraulic brake system of a motor vehicle, comprises fluid pumping equipment (1) for pumping fluid to a main fluid reservoir (8) of the fluid system via a supply conduit (24). The pumping equipment (1) includes a fluid container (6) and an air pump (2) serving to discharge fluid from the container (6) into the supply conduit (24). The pump (2) is driven through an electric circuit (C1.C2) including a fluid pressure control (14) and a fluid level control (15A) of the container (6). The delivery end of the supply conduit (24) passes through an opening (26) of the reservoir (8) which opening (26) is sealed by an elastomeric plug (18) laterally expandable by a compression device. The above apparatus considerably conveniences the bleeding of motor vehicle brake systems.

Abstract: A device is provided for bleeding entrapped gas from a master brake cylinder assembly when the latter is removed from a vehicle or prior to the assembly being installed in the vehicle and all of the outlet ports of the assembly are plugged. The device includes a support member having an upright section with a transversely extending passage formed therein. Removably mounted on one side of the upright section is the master cylinder assembly. The assembly is positioned so that an access opening which is formed in one end of the cylinder assembly to provide access to an end portion of a primary piston of the assembly, is aligned with and is adjacent to the passage in the upright section. Disposed in spaced relation to the opposite, or second, side of the upright section is an actuating unit which is mounted on the support member for selective manual adjustment between operative and inoperative modes.

Abstract: This apparatus for removing air from a hydraulic system having a master cylinder, a wheel cylinder disposed at a lower level than the master cylinder, with a hydraulic line connecting the cylinders, and an adjustable bleed nipple at the brake cylinder. The method includes the steps of filling a syringe with fluid and injecting it into the wheel cylinder via the open bleed nipple and through the hydraulic line to the master cylinder where air bubbles rise in the fluid therein and are dispersed to ambient air.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately, but simultaneously, filled with hydraulic fluid after simultaneous evacuation of atmospheric air from the apparatus modular units and test of the integrity of the modular units, and the pre-tested and prefilled modular units are shipped unconnected to a user.

Abstract: The invention comprises a method for more efficiently bleeding a hydraulic system of air comprising a method of reversing normal flow of the hydraulic fluid within the hydraulic system, externally recirculating hydraulic fluid from a reservoir at the one end of the system to a cylinder at another end of the system, and watching the system reservoir for bubbles evidencing the escaping gas, and a pump apparatus for efficiently implementing the method.

Abstract: A master-slave hydraulic control system preferably for actuating a vehicle clutch utilizes single-acting hydraulic cylinders which are both connected to a fluid reservoir. The higher mounted cylinder has a bleed valve in the line connecting that cylinder with the fluid reservoir. The lower mounted cylinder is connected to the fluid reservoir via a check valve. The check valve allows fluid communication between the reservoir and the lower cylinder when the pressure within that cylinder is below a predetermined value. The hydraulic system may be bled regardless of the position of extension of either cylinder.

Abstract: A dual-piston hydraulic brake master cylinder includes a large hydraulic piston which supplies an initial large brake fluid volume and a small hydraulic piston which continues to supply brake fluid to the brakes when the large piston stops moving forward in its cylinder at higher brake pressures. The small, central hydraulic piston is connected to the end of a piston rod extension of a pneumatic booster piston. The large piston surrounds the small piston and opens a reservoir line tilt-valve in the piston retracted position. A passageway between the large and small hydraulic chambers is open in the retracted position to allow communication of braking fluid therebetween. During brake actuation a seal arrangement interrupts this communication. The large and small hydraulic chambers supply the brake circuits through delivery passages.

Abstract: A hydraulic fluid bleeding apparatus for removing air from a closed hydraulic brake system. The invention includes a container, a sealable lid for the container, and two conduits air tightly mounted through the lid. The first conduit includes a liquid level check valve positioned at the inner distal end within the container when the lid is secured thereto for closing off the vacuum source to the inside of the container when fluid level therein reaches a certain level. The outer distal end of the first conduit is connectable by flexible hose or the like to a vacuum source such as that within a running engine's intake manifold. The outer distal end of the second conduit is connectable to the brake system's bleed valve or petcock. The inner distal end of the second conduit is maintained at negative pressure by the vacuum condition within the container to effect brake fluid withdrawal from the bleed valve.

Abstract: This invention relates to hydraulic master cylinder assemblies having a hydraulic master cylinder and an actuating mechanism and in particular to a hydraulic master cylinder assembly in which it is possible to alter the travel ratio between a driver operable actuating lever and a piston of the hydraulic master cylinder. The actuating mechanism includes a lever mechanism interposed between the actuating lever and the piston the effective lever arm length of which can be altered by means of an adjustable member forming part of the lever mechanism.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. A leakproof quick-connect connector is placed between the master cylinder and the slave cylinder, preferably at the end of the conduit where it connects to the master cylinder or the slave cylinder, one member of the connector forming part of the master cylinder or slave cylinder. The apparatus, after assembly, is filled with hydraulic fluid, the two members of the connector being held momentarily engaged. After filling, the connector is broken, and the filled components are shipped to a user. After installation of the apparatus for operation of a mechanism such as a clutch release mechanism, the two connector members are reconnected, and the connector members having been provided with a one-way locking member can no longer be separated such as to preserve the integrity of the system.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately, but simultaneously, filled with hydraulic fluid after simultaneous evacuation of atmospheric air from the apparatus modular units and test of the integrity of the modular units, and the pre-tested and prefilled modular units are shipped unconnected to a user.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately filled with hydraulic fluid, and the filled modular units are shipped unconnected to a user. Each modular unit is provided with a leakproof quick-connect connector member, through which filling of the modular unit may be effected, and which mates with a complementary leakproof quick-connect connector member of another modular unit, such that after installation on a utiization device, a motor vehicle for example, complementary connector members are reconnected, thus opening ports in each connector member placing each member in fluid communication with the other. Preferably, the two connector members are provided with a one-way locking arrangement preventing separation of the connector members after coupling.

Abstract: A method of shipping and installing a hydraulic system such as a motor vehicle clutch hydraulic release mechanism comprising a driver-operable hydraulic master cylinder, a hydraulic slave cylinder and a conduit connecting the outlet of the master cylinder to the inlet of the slave cylinder. Prior to shipment and installation on a motor vehicle, the hydraulic system is filled with hydraulic fluid and bled or purged of atmospheric air, and installation on a motor vehicle is therefore greatly simplified as the requirement of filling with hydraulic fluid and bleeding or purging the hydraulic system after installation is entirely eliminated.

Abstract: A wheel cylinder assembly has telescoping brake actuating pistons with a brake pressure proportioner in the larger actuating piston to proportion brake actuating pressure.

Abstract: A liquid reservoir for a hydraulic master cylinder, having a body with a detachable cap for refilling the reservoir, and a diaphragm secured in position by the cap and dividing the reservoir into an air chamber, vented to atmosphere via a hole in the cap and a liquid chamber connected to the master cylinder. An inlet port is provided in the wall of the reservoir for initial charging of the liquid into the liquid chamber without removal of the cap, the port being closed by a plug after the liquid reservoir has been filled. The method of filling a hydraulic control system which has such a reservoir is by the application of vacuum to the system via the inlet port, introducing liquid into the system through the port and subsequently sealing the port with the plug.

Abstract: A liquid reservoir for a hydraulic master cylinder, having a body with a detachable cap for refilling the reservoir, and a diaphragm secured in position by the cap and dividing the reservoir into an air chamber, vented to atmosphere via a hole in the cap and a liquid chamber connected to the master cylinder. An inlet port is provided in the wall of the reservoir for initial charging of the liquid into the liquid chamber without removal of the cap, the port being closed by a plug after the liquid reservoir has been filled. The method of filling a hydraulic control system which has such a reservoir is by the application of vacuum to the system via the inlet port, introducing liquid into the system through the port and subsequently sealing the port with the plug.

Abstract: A stationary pressure bleed stem and a movable pressure bleed stem are mounted on a base plate to adjust for varied spacing between the master cylinder ports at the reservoir bottom. The fixture is clamped over the master cylinder reservoir. The stems may be interchangeable with other similar stems of various dimensions to accommodate for variations in dimensions of different master cylinders. The device simplifies and expedites pressure bleeding of master cylinders having different configurations.

Abstract: A hydraulic fluid reservoir for automobile including a plurality of fluid chambers separated by a partition, the fluid chambers being communicated with hydraulic systems in the automobile respectively, and a baffle plate between the upper end of the partition and an inlet at the upper portion of a reservoir body to define openings of the respective fluid chambers at predetermined ratios which define the flow rates of fluid into respective fluid chambers.

Abstract: A hydraulic fluid reservoir for automobile including a partition wall within a reservoir casing defining a float chamber and extending from the bottom of the reservoir casing, a float which is movable in said float chamber so as to cause a switch to close or open at a predetermined float level, a communication opening communicating the float chamber with the outside chamber of the partition wall at the lower portion thereof and a fluid reflection cover disposed on the float chamber, malfunction of the level detector is avoided.

Abstract: The wheel cylinder bleed passage is incorporated in the brake fluid connector mounting bolt and includes a ball check valve assembly fitting for bleeding purposes.

Abstract: A tandem brake master cylinder comprising a longitudinal bore having two pressure chambers therein each associated with a different one of two pressure pistons, each of the two pressure chambers and its associated one of the two pressure pistons are associated with a different one of two brake circuits. Two parallel inlet sockets are provided in the housing of the tandem master cylinder, each of the two inlet sockets connecting a different one of the two pressure chambers to a brake fluid reservoir. A transverse bore is also provided in the housing of the tandem master cylinder containing a pressure control device for one of the two brake circuits, the control device including a stepped piston and a valve controlled by the stepped piston. The transverse bore intersects a plane containing the axes of the two inlet sockets in an approximate perpendicular manner between the two inlet sockets and beween the longitudinal bore and the reservoir.

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 toggle assembly for vehicles or cars comprising a relay cylinder mounted on an end plate including a booster cylinder and an output cylinder, a control chamber arranged in coaxial relation to the relay cylinder, a control valve for controlling a gas by a hydraulic pressure of a master cylinder, said valve being arranged in operable association with the control chamber, and a booster piston disposed in the booster cylinder and in operable association with the controlled gas, wherein said end plate is provided with a shell for said booster cylinder as an integral piece, said shell is integrally provided with a first compressed air passage having its one end being open in the back chamber of the booster cylinder for the booster piston and its other end passing through said end plate and being open at the end of a relay valve body, and a second compressed air passage is provided to extend from a casing for said control chamber, said second passage having its one end in communication with the other open end of s

Abstract: Friction clutch release apparatus for a motor vehicle comprises a driver-operable master cylinder, a slave cylinder and a conduit which connects the master outlet to the slave cylinder inlet. A liquid reservoir communicates with the bore of the master cylinder between the piston and the outlet when the piston is retracted and has a vent port. The apparatus is assembled, filled with liquid and bled before being installed on the motor vehicle. The vent port may be closed temporarily for convenience of transport and storage after the apparatus is bled, for example by use of a suitable removable closure device which would be removed after installation of the apparatus on the motor vehicle, or may include a movable wall within the reservoir chamber by which liquid within the chamber is separated from that part of the chamber with which the vent port communicates.

Abstract: A land plane for leveling or grading the surface of a land area. The plane includes a frame defined by a center section and end sections pivotally connected to the center section, with each connection permitting relative physical movement about an axis transverse to the longitudinal axis of the plane. A first hydraulic system is provided for pivoting the end sections about their transverse axes for raising and lowering the center section with respect to ground level, wherein the system includes a device for equalizing fluid between hydraulic cylinders carried by the end sections to permit adjustment of the grader assembly with respect to ground level under different operating conditions.

Abstract: A fluid-operated brake embodying a pressurized fluid chamber with a single supply and bleed fitting is provided. The pressurized fluid chamber can be a wheel cylinder of a drum brake or a caliper housing of a disc brake, by way of example. The chamber has a single port therein in which a fitting is mounted, the fitting being designed to supply fluid under pressure to the chamber and to bleed gas, commonly air, from the chamber. With only a single opening for the chamber, one boss can be eliminated to save weight, and machining of that boss is also eliminated to save costs. The single opening also achieves greater flexibility in design options.

Abstract: A liquid pressure control system for advancing logs (19) towards a rotary cutter wheel (10) in timed relationship to successive cuts by cutters on that wheel (10). A cam arrangement (52) on the cutter wheel (10) actuates jerk pumps (71 and 72) to dispense hydraulic fluid to hydraulic rams (33 and 34) in the timber feed mechanism (18).

Abstract: A bleeder kit for use in bleeding a master cylinder in a hydraulic brake system is disclosed wherein the kit includes a number of unidirectional flow valves and a corresponding number of flexible conduits suitable to connect a valve to each outlet port on the master cylinder housing, with a flow conduit connected to each valve so as to unidirectionally direct brake fluid from the master cylinder bore into the master cylinder reservoir upon pressurization of the brake fluid within the master cylinder. A hose clip is releasably mountable on the reservoir and operative to guide the discharge ends of the flow conduits into the reservoir.

Abstract: A brake bleeder adapter, for use with automotive brake system master cylinders having reservoirs which should not be subjected to clamping and/or bleeding pressures as was done according to prior methods of brake bleeding, connects the hydraulic brake system of the automobile to a supply of pressurized brake fluid without subjecting the reservoir to such pressures during the process of bleeding the brakes. When securing this adapter to the brake system, the master cylinder fluid reservoir is essentially by-passed and the adapter is connected directly to the master cylinder. Entrained air within the replacement brake fluid is effectively prevented from entering the brake system by either releasing such air from the fluid or confining it to the fluid remaining in the adapter thus reducing the time needed to complete the bleeding process.

Abstract: An auxiliary hydraulic fluid circuit for purging air from a hydraulic brake system in either an agricultural or industrial type of tractor vehicle by diverting hydraulic fluid through the auxiliary circuit from the hydraulic power system of the tractor into the hydraulic brake system. The fluid diverted into the brake system is observed flowing, through transparent means in conduits comprising the auxiliary circuit, until the fluid flow is clear, to the reservoir of the hydraulic power system. At which event, the brake system is now purged of air and the hydraulic circuit is disconnected between the tractor hydraulic power and brake systems.

Abstract: The invention resides in a harness adapted for connection with various master cylinders provided in automotive brake systems includes two body members connected together by a hose and adapted for thrust connection to a dual master cylinder at its two inlets to supply brake fluid under pressure to the master cylinder from a tank or other source. The thrust connection of each member is maintained by an adjustable elastic strap which extends around the master cylinder and has selected portions received and retained within open end key hole slots in opposite ends of a cross bar carried by the member for the purpose of bleeding air from such systems.

Abstract: Hydraulic pulse generating apparatus for actuating one or more slave motors, comprises at least one hydraulic master cylinder, which in use is connected to a slave motor by flexible tubing or otherwise.The master cylinder is fitted with a reciprocating plunger which is operated by power actuated driving means, and the cylinder communicates with a hydraulic fluid reservoir which is maintained at a pressure intermediate the maximum and minimum pressures produced in the cylinder by operation of the plunger.Manual control means are provided, to prevent the transmission of pressure pulses to the motor while the power actuated driving means continues to operate and for this purpose the master cylinder preferably communicates with a transfer chamber, the volumetric capacity of which is variable by operation of the manual control means.Means are also provided whereby, when the capacity of the transfer chamber is thus increased beyond its normal capacity, the further inflow of fluid from the reservoir is prevented.

Abstract: A hydraulic brake system for the hoist drum of a lifting crane to achieve good control over loads being held or lowered by the load line wrapped on the hoist drum comprises a brake band for exerting a braking force on the hoist drum. The system further comprises a brake cylinder for operating the brake band; a brake valve for controlling the supply of fluid from a fluid source to the brake cylinder; a brake pedal for operating the brake valve and movable between a brake release position and a brake applied position; a valve toggle linkage connected between the foot pedal and the brake valve piston to cause the brake valve to supply fluid to the brake cylinder at a predetermined pressure when the pedal is depressed to a first brake applied position and for applying fluid at a greater pressure when said pedal is moved to a second brake applied position which offers a mechanical advantage; and a hydraulic simulator for adjusting the position to which the foot pedal can be depressed.

Abstract: A fishing reel, of the type having a rotating line spool, includes an hydraulic braking system for the spool. The braking system comprises a manually operable lever associated with a piston in a first hydraulic cylinder through which fluid forces are applied to a second piston operating friction plates bearing upon the reel spool. A third, spring loaded, piston is located in a second cylinder in fluid connection with the first cylinder.

Abstract: Hydraulic systems comprising master and servo cylinder assemblies are sometimes bled only with difficulty, and even then not effectively.The invention provides a method of bleeding such systems, which involves the introduction of hydraulic fluid into the servo cylinder via a hydraulic connector having a fluid feed passage and a non-return valve therein. The fluid passes from the servo cylinder into the master cylinder. The hydraulic connector has engaging means for engaging with a connecting member of a hydraulic fluid feed line. A removable dust cap co-operates with the engaging means to seal off the passage and to protect it against dust and foreign matter when the engaging means is not connected to the connecting member.

Abstract: A position-transmitting equipment especially suitable for transmitting steering commands in a small watercraft comprises a transmitter unit in which a cylinder is reciprocable endwise in a housing in accordance with position information to be transmitted. The cylinder is divided internally into two working chambers by a transverse partition. A gland at each end of the cylinder seals about a tubular plunger fixed to the housing so that reciprocation of the cylinder differentially adjusts the working chamber volumes, without risk of jamming and the need for close tolerances. The housing, cylinder and plungers can all be made of plastics material. The plungers provide communication via conduits to a double-acting actuator constituting a receiver unit. The equipment optionally includes a recuperator unit to maintain a selected working fluid pressure in the system.

Abstract: This invention relates to hydraulic master cylinder assemblies having a hydraulic master cylinder and an actuating mechanism and in particular to a hydraulic master cylinder assembly in which it is possible to alter the travel ratio between a driver operable actuating lever and a piston of the hydraulic master cylinder. The actuating mechanism includes a lever mechanism interposed between the actuating lever and the piston the effective lever arm length of which can be altered by means of an adjustable member forming part of the lever mechanism.