Abstract: A self contained hydraulic valve system, for controlling the flow of a normally gaseous fluid such as, for example, anhydrous ammonia, includes a hydraulic valve connected to a pressurized vessel holding said normally gaseous fluid, a master cylinder hydraulically connected to said valve and controlling the operation thereof, and a hydraulic connection between the hydraulic valve and master cylinder. In operation, when the manual lever of the master cylinder is depressed, the hydraulic fluid within the self-contained system is pressurized thereby forcing the hydraulic valve open.

Abstract: In a reservoir assembly for a tandem master cylinder of a hydraulic braking system the container is separated into compartments by at least one baffle passages being provided for permitting limited communication between the compartments past the baffle. The arrangement is such that when the container is installed in a vehicle and the brakes are applied, the tendency of fluid to transfer from one compartment to another is resisted. The arrangement also ensures that even under the worst conditions of deceleration and altitude of the vehicle there will be a sufficient volume of fluid in the compartments to cover outlets to the master cylinder and thus sustain subsequent brake application.

Abstract: A pneumatic control device for a displaceable member of an electric circuit, having a compressible air reservoir adapted and connected by a flexible conduit to an enclosure comprising the said movable member, and comprising three superposed rigid or semi-rigid members which are at least partially housed or enclosed one inside the other, and at least one member having a compressible wall and having an edge which is engaged and clamped between two of the superposed rigid or semi-rigid members; the first of said members together with the compressible walled member delimiting the air reservoir and being provided with a nozzle leading into an inner chamber which is delimited by the assembly of said three rigid or semi-rigid members; the second and third of said members delimiting a passage between them which connects the inner chamber to an annular outer chamber delimited by the second and the third rigid or semi-rigid members and open at its periphery; said flexible conduit being connected to the nozzle in the in

Abstract: A device comprising two oil reservoir tanks communicating with the two respective oil-hydraulic chambers of a tandem type master cylinder and also with each other through an upper and a lower interconnecting oil passage. One of the two tanks has a top opening for oil filling use and normally closed with a vented cap while the other tank is closed at the top and provided therein with an oil level detector means which comprises a stationary reed switch connected with an appropriate external alarm circuit and a permanent magnet vertically movable with the oil level in the tank to close the reed switch as the volume of oil stored is reduced to a predetermined minimum. With the device, even if one of the two oil-hydraulic lines connected with the master cylinder fails to function due to oil leakage, the other line can properly function without any pressure failure as, in the associated tank, a predetermined minimum volume of oil remains on account of the height of the lower oil passage.

Abstract: A tandem master cylinder comprises two pistons, one of which includes a cylindrical bore for receiving therein the other piston, and limiting means for limiting the axial movement of the other piston.

Abstract: An auxiliary compensating piston in a tandem automotive master cylinder containing two pressure pistons closes relief port holes between the cylinder and brake fluid reservoirs. A compensating valve feeds replacement fluid into the cylinder during brake release. The auxiliary compensating piston opens the relief port holes at the end of brake release to relieve excess brake fluid from the cylinder.

Abstract: A brake master cylinder contains a primary and a secondary piston each having an associated brake fluid reservoir and compensator valve. Normally, the primary piston is actuated directly by mechanical force and the secondary piston is actuated by fluid pressure acting on it from the primary cylinder. If brake fluid pressure fails in either primary or secondary piston regions, the unfailed piston thereupon responds directly to mechanical actuating forces to produce normal brake fluid pressure in its associated wheel cylinders without interference from the failed piston.Compensator valves, external to the cylinders enable brake fluid replenishment without requiring additional cylinder length.

Abstract: Master cylinder reservoir comprising a housing having two adjacent reservoir sections separated by a transversely extending double wall partition having windows offset laterally from one another with a space between the walls.

Abstract: A master cylinder for a two-circuit brake system which includes anti-skid control has two separate chambers and pistons. The main control piston is surrounded by an auxiliary piston which it engages after a predetermined amount of travel. The auxiliary piston has an extension which holds the brake control valve and which is opened by the control piston during its travel. Furthermore, the second circuit cylinder includes a pressure sensor which can activate a warning when the piston travel is not in a predetermined relation to the applied fluid pressure.

Abstract: In a sealed fluid reservoir for a hydraulic brake master cylinder, inlet and outlet check valves are compactly assembled with a reservoir cap to constantly seal brake fluid stored in the reservoir against the surrounding air. The inlet and outlet check valves are selectively opened in response to rise or drop of the level of fluid in the reservoir to ensure smooth fluid supply to the brake master cylinder.

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 break release but preventing flow from the quick take-up chamber during brake apply. A normally closed check valve is held open while the master cylinder is in the fully released position to provide communication between both pressurizing chambers and the fluid reservoir. As the pressurizing cup for the high pressure chamber closes its compensation port, the check valve is permitted to close by camming action of a valve pin and a camming surface on the piston. Initial flow is obtained from the quick take-up chamber past the pressurizing cup into the high pressure chamber.

Abstract: A master cylinder reservoir molded of glass fiber filled nylon. An integrally molded window in a side wall is thinner than the reservoir walls and has a lower concentration of fibers so that it is sufficiently translucent to permit visual determination of the level of hydraulic brake fluid in the reservoir by observation through the window. The method of making the reservoir by molding, in which the flow of fibers into the window section is restricted to reduce the fiber concentration in the window and make it more translucent, is also disclosed.

Abstract: A master cylinder assembly for simultaneously actuating the front and rear wheel brakes of a vehicle. The master cylinder assembly includes a housing having a bore therein with a first piston separated from a second piston by a first spring to establish a first pressurizing chamber while a second spring separates the second piston from the bottom of the bore to establish a second pressurizing chamber. The first and second piston each have a compensating passage therethrough for communicating fluid from a reservoir into the first and second pressurizing chamber, respectively. A first valve seat located in the first pressurizing chamber is connected to a second valve seat in the second pressurizing chamber. A valve return spring in the second pressurizing chamber urges the first and second valve seats toward the first and second pistons.

Abstract: Master cylinder reservoir comprising a housing having two adjacent reservoir sections separated by a transversely extending double wall partition having windows offset laterally from one another with a space between the walls.

Abstract: A hydraulic booster unit and system for use in operating hydraulic units, such as work holding hydraulic cylinders, from a compressed air power source is disclosed. The booster includes a unique refill unit that automatically feeds hydraulic fluid from a reservoir to the booster to replace lost fluid during use, and also includes an alerter for giving warning on the onset of a low fluid condition (such as may occur from an exhausted reservoir or excessive leak), and thus protects against excessive leakage as well as the dangers to the work piece and worker inerent in a low fluid condition. The alerter may be a visual unit or a compressed air-operated audible alarm or both.

Abstract: A reservoir in a master cylinder for use in a vehicle braking system comprising two or more barrier plates vertically spaced and fitted in the reservoir to partition the interior of the reservoir into three or more chambers. Each of the plates has one or more through holes for restricting fluid flow across the plate, thereby preventing ingress of air bubbles into pressure chamber of the master cylinder.

Abstract: The hydraulic master-cylinder of the invention is of the kind having a valve ring made of elastomeric material mounted on the head of a piston adjacent to the pressure chamber. The master-cylinder further includes a safety valve in the pressure chamber. The safety valve is guided on the piston head and is adapted to sealingly cooperate with both one face of the valve ring and a shoulder provided on the piston head. The safety valve is biased toward the valve ring by a spring abutting on a stop fixed relative to the piston.

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: Hydraulic input-output device working with a hydraulically unbalanced system. This is made possible according to the present invention by in a useful way taking advantage of the pressures, which arise upon actuation in a hydraulically unbalanced system, in that the created fluid differential can be translated to a fluid flow towards or away from a fluid accumulator.

Abstract: A master cylinder of the dual pressurizing chamber type for pressurizing brake fluid in separate brake actuating circuits has the primary piston reciprocably mounted in a stepped bore so that the piston rear land moves within a larger bore section than does the piston front land. The secondary piston moves in the same bore section as does the primary piston front land, and has a pair of spaced lands with oppositely facing lip seals. The front land of the primary piston is also provided with a lip seal. These seals operate to permit the build-up of pressure in the pressurizing chambers located on either side of the secondary piston, while permitting fluid to flow past the seals into the pressurizing chambers when the chambers adjacent the pressurizing chambers are producing a greater pressure than that being produced in the pressurizing chambers.

Abstract: A master cylinder having an indicator activated by either a low level fluid condition in a reservoir or any operational pressure imbalance between first and second fluid distribution systems of a master cylinder to inform an operator of an adverse condition which could affect braking.

Abstract: A master cylinder assembly for simultaneously actuating the front and rear wheel brakes of a vehicle. The master cylinder assembly includes a housing having a bore therein with a first piston separated from a second piston by a first spring to establish a first pressurizing chamber while a second spring separates the second piston from the bottom of the bore to establish a second pressurizing chamber.The second piston has a first passage which connects the first pressurizing chamber to a reservoir in the housing and a second passage which connects the second pressurizing chamber to the reservoir. A guide on the second piston is located in a keyway in the housing to prevent the second piston from rotating. A first telescoping sleeve member located on the first piston is aligned with the first passage while a second telescoping member attached to the housing is aligned with the second passage.

Abstract: A joint, subject to a pressure differential between inside and outside, having two tubular members flexibly joined by couplings comprising an annular piston sliding within an annular cylinder containing an incompressible fluid, a fluid reservoir connected to and at a higher pressure than the cylinder interior and valve means responsive to fluid loss from the cylinder allowing fluid flow from reservoir to cylinder. The valve may comprise two semi-circular arms pivoted at their ends to each other and to the piston or cylinder, the arms operating on opposite ends of a rocker plate attached centrally to a valve plunger. A differential piston maintains the high reservoir pressure. The valve is adjustable to operate at a predetermined value of cylinder fluid volume.

Abstract: An apparatus for reciprocating a piston in a diaphragm pump wherein the piston alternately pressurizes and relieves an oil filled chamber having a diaphragm separating the chamber from a liquid pumping chamber, the invention comprising a bearing shoe interposed between the piston and driving crank shaft, wherein the shoe has oil ports for lubricating and for relieving excess fluid volume from the oil chamber during each piston stroke.

Abstract: Dual master cylinders are arranged to apply hydraulic pressure to a single set of vehicle brakes through a double check valve and single brake fluid conduit. A first of the master cylinders is actuated by compressed air in response to manipulation of an operator's service brake control, while the second master cylinder is actuated to a lesser extent by compressed air responsive to an operator's retarder control. A modulatable emergency brake control may independently and simultaneously actuate both master cylinders together with a third master cylinder coupled to separate brakes. Thus, braking capacity remains available if the service brake system or the retarder brake system or both should fail, or if the emergency system should itself fail while either the service system or the retarder system remains functional.

Abstract: A device for compensating temperature dependent volume variations in a closed pressure medium system where at least two variable volume members are connected via a pipe to each other for transfer of movement between each other. At least one of the movement transmitting members has two ends freely movable relative to the pipe. One of the ends cooperates with a support, the position of which varies with the temperature as the volume of a flexible means, which is rigidly attached to the pipe, changes. The other end of the movement transmitting member is freely movable relative to the flexible means.

Abstract: A pressure differentially controlled valve for use in a two stage servomotor to prevent reversion from the second stage to the first stage. A first valve initially moves to transfer the output of a servomotor from a first piston to a second piston. A pressure differential responsive second valve prevents the output of the second piston chamber from being communicated to the first piston chamber by moving thereafter with the first valve until an input force is terminated.

Abstract: A combined fluid motor and pumping apparatus including a unitary multi-land piston device having a motor piston end slidably mounted in a motor portion of an elongated tubular housing and an opposite pump piston end slidably mounted in an opposite pumping portion of the housing wherein the working area of the motor piston end is provided with a greater effective working area than the pump piston end so that upon directing a source of fluid at a predetermined pressure against the motor piston end of the piston device the pumping portion is effective to pressurize a work system to a higher pressure than the pressure at the source of fluid with the housing incorporating a fluid reservoir in the motor portion for making up fluid losses in the pumping portion.

Abstract: A multi-circuit brake installation for vehicles, in which two transmitter brake pistons which possess differently large effective brake pressure piston areas and which are hydraulically connected with each other, operate within a master brake cylinder actuatable at will by means of a servo-assist; these two transmitter brake pistons are connected into a respective brake circuit and are provided with corresponding means for limiting the relative movement with respect to one another, whereby control means are provided independent of the brake circuit for disengaging the hydraulic drive connection between the two transmitter pistons, which are displaced positively into the disengaging position exclusively upon the occurrence of a critical value of the servo-assist.

Abstract: In a servomotor having a first diameter piston concentric to a second diameter piston for supplying a braking system with a first pressurizing force and a second pressurizing force in response to an operator input. A transfer valve has a first face and a second face which are located on opposite sides of a radial bore in the second piston to receive a first pressurizing force. The transfer valve has an axial passageway therethrough which communicates relief or reservoir pressure to the first and second faces of the transfer valve to provide a balance pressure force on the same. A spring holds the second face of the transfer valve against a seat to prevent communication of the first pressurizing force into the relief chamber.

Abstract: A cover for a retention chamber in a master cylinder reservoir which will permit a probe to pass through a tab and pressurize a piston in a pressurizing chamber with a test fluid under pressure. This test fluid will allow an operator to visually inspect the master cylinder for fluid failures at various pressures. In the normal operation, the tab of the cover will allow fluid to flow from a supply chamber into the retention chamber. However, during a brake application when fluid is transmitted through the compensator port as the pressurizing piston moves past the compensator port, the tab will prevent this fluid from being squirted into the supply reservoir. This will assure that a minimum quantity of fluid is always present in the retention chamber to operate the brake system even though a low fluid level indicator in the supply chamber presents a failure warning signal to the operator.

Abstract: A hydraulic clutch system comprising a first piston and cylinder assembly including a piston rod for causing a first piston to move within a first enclosure in response to actuation of a vehicle clutch pedal or the like, a second piston cylinder assembly including a second piston movable within a second enclosure from a non-actuated position to an actuated position to operate a vehicle clutch mechanism, a fluid circuit including a hydraulic conduit communicating fluid from one end of the first enclosure to the second enclosure and operable to bias the second piston from the non-actuated position toward the actuated position, a fluid reservoir communicable with the fluid circuit, and a valve operative in response to preselected movement of one of the pistons within the associated of the enclosures for communicating the reservoir with the conduit.

Abstract: A master cylinder having a secondary piston for absorbing rapid initial pressure increases in proportion to the stroke of the primary piston. The master cylinder includes a housing having a first cylinder formed therein. A first piston is movable within the first cylinder. A second cylinder is formed in the first piston. A second piston is movable within the second cylinder.

Abstract: A hydraulic linkagae for transmitting reciprocating motion comprising a master unit, a slave unit, the master and slave units each comprising a pair of interconnected rod pistons reciprocally moveable within the cylinders in opposite directions by a force applied to the pistons, hydraulic lines connecting one master cylinder to one slave cylinder for transmitting motion from master to slave, a reservoir, a pair of one-way pressure valves mounted in opposite directions and in parallel between the reservoir and each master-slave connection so that volumetric increases in the fluid in the system will be forced out through a first valve of each valve pair and to the reservoir, and volumetric decreases in the fluid in the system will draw fluid from the reservoir through a second valve of each valve pair, thereby providing volume change compensation.

Abstract: A hydraulic brake force-multiplying device includes a body, an output member fitted slidably in the body, a working chamber defined between the output member and the body, a pressure chamber defined in the body and receiving pressure fluid introduced from a source of pressure fluid, a valve seat member positioned in the pressure chamber and urged against the body under fluid pressure of the pressure chamber, a rod member provided integrally with the valve seat member and extending to the interior of the working chamber, a guide bore extending through the rod member axially, a valve stem having a valve portion adapted to cooperate with a valve seat of the valve seat member, thereby forming a valve mechanism in combination with the valve seat, and being sealingly and slidably fitted in the guide bore, an input shaft provided in the body adjacent to one end of the valve stem remote from the working chamber, an intermediate chamber defined between the input shaft and the valve stem and adapted to be communicated

Abstract: A dual master cylinder has a cylinder housing in which one bore is provided. A pair of pressurizing pistons are mounted in tandem in the bore to define therewith a pair of pressurizing chambers. Each chamber is connected to a separate brake circuit. The cylinder housing also has formed in it a pair of secondary reservoir chambers which are connected to the bore by compensation ports. A single primary reservoir chamber is formed by a stamped metal reservoir body which is secured to the cylinder housing over the secondary reservoir chambers so as to cover those chambers and seal them. Fluid transfer ports through the bottom of the reservoir body connect with the secondary reservoir chambers, and have their axes axially misaligned relative to the axes of the compensation ports so that fluid returning to the reservoirs through the compensation ports will not be able to enter the primary reservoir chamber when a squirting action takes place.

Abstract: 6.