Societe Anonyme Francaise Du Ferodo

Valeo Corporation

Valeo Societe Anonyme

Jean L Dauvergne

Patrice Bertin

A hydraulic distributor device comprises two members movable relative to one another, either in rotary or translational movement, along a planar sliding interface, at least one narrow groove being provided superficially in one of the members along the interface, so as to minimize or eliminate the axial thrust generated by the fluid pressure. The distributor device may be used in power-assisted steering apparatus for a vehicle.

Hydraulic distributor devices

The invention provides a power assisted hydraulic control system suitable for actuating clutches and brakes. The system incorporates a master cylinder having a master piston therein defining a control chamber, a hydraulic power assistance unit, and a distributor adapted to connect, by means of a slide valve, the power assistance unit with the hydraulic receiver controlling the brake or clutch unit. The distributor comprises a slide-valve having a plunger one end of which is subjected to the pressure in the control chamber and the other end of which is subjected to the pressure in the receiver. A bypass channel links the control chamber of the master cylinder to the pipeline connecting the operating port of the distributor to the receiver. The bypass channel has a bypass valve controlled by a spring which opens in the event of failure of the power assistance to permit manual operation by the master piston.

Power assisted hydraulic control system

A hydraulic control system, for at least one hydraulic braking circuit, comprising a control unit, a brake pedal, an assisting hydraulic pressure plant having a fluid pressure source and a reservoir, a distributor valve having a slide fitted movably in the control unit between a rest position, when the braking circuit connects with the reservoir, and an active position, when the braking circuit is pressurized. This slide is urged in one direction by the pedal and in the opposite direction by the pressure in the braking circuit. The slide moves only about a millimeter, and to give the driver a resonable pedal displacement, a first resilient device, in the form of either stepped parallel or in series helical springs or an elastomer block, is disposed between the pedal and slide. To avoid excessive braking except in a real emergency, a second resilient device, either a spring or the elastomer block, is disposed between the pedal and unit and is adapted to be actuated by the pedal for only a fraction of the pedal stroke at its end of travel, to warn the driver that the end of travel is being approached.

Hydraulic control system

The invention relates to a master cylinder for an automobile braking circuit which is suitable for dual-circuit or single-circuit application. The master cylinder has at least one chamber connected to the braking circuit, the pressure in the chamber being controlled by depression of a master piston by a brake pedal. An auxiliary hydraulic circuit is connected to the master cylinder and this circuit has a source of pressure and a jack, a piston of which co-operates with the master piston to cause depression thereof; a distributor is provided suitable for feeding the jack with auxiliary hydraulic pressure from the source, the distributor having a slide valve which is subjected to two opposing forces, one of which is developed by the auxiliary hydraulic pressure and the other of which is developed by the action of the pedal via means for transmitting this force between the pedal and the slide valve, with the intervention of elastic means for simulating the pedal movement, and manual backup means acting on the master piston, from the pedal, in the event of failure of the auxiliary circuit. A movable member in the master cylinder which is controlled by the auxiliary hydraulic pressure at the same time as the slide valve of the said distributor, is associated with the elastic means for simulating the pedal movement, so as to put these means out of action in response to a failure of the auxiliary hydraulic pressure. According to the invention, the manual back-up means, the movable member, and the slide valve of the distributor act respectively along three separate and parallel axes.

Hydraulic control device for a motor vehicle braking circuit

The invention relates to a device for the power-assisted steering of a vehicle, of the kind comprising a steering column in two parts which are capable of limited relative angular displacement on either side of a neutral position. The assistor means are adapted to act on the steering system in the same sense as the steering column in response to this angular displacement, and comprise a hydraulic power source, a distributor, and an assisting jack. The distributor comprises stators connected to the power source and the jack, and two corresponding rotors each integral with a respective part of the steering column and being provided with passages for the hydraulic fluid. According to the invention, elastic means for returning the parts of the steering column to the neutral position comprise an elastic return arm integral with one of the rotors, which is connected to the other rotor, the neutral position of elastic return being coincident with a position of the rotors in which no fluid is directed to the assisting jack. The formation of the elastic means integrally with a rotor means that these parts can be formed by stamping from a single blank. The assembly is therefore cheaper and simpler than the previous torsion bar arrangements.

Power-assisted steering device and the manufacture thereof

The invention relates to a power-assisted braking device of the kind having a master piston sliding in a master cylinder, a jack having a piston linked to the master piston by an interconnection such as a rod, a source of auxiliary hydraulic pressure, and a distributor which feeds the jack with auxiliary hydraulic pressure and which is operated by a brake pedal and two mutually articulated levers. The unit consisting of these two levers cooperates with a fixed point and has three working points of which the first cooperates with the pedal, the second cooperates with the distributor and the third cooperates with the master piston. According to the invention, the first and second working points are located on one of the levers (the primary lever) and the fixed point and the third working point are located on the other lever (the secondary lever). This enables the distributor to be acted on directly by the pedal thereby providing more precise operation.

Assisted braking device

An assisted steering device for a vehicle has a steering column in two parts which are capable of limited relative angular play, permitting angular offsetting of the parts under the effect of the steering wheel. This enables two rotor discs, movable respectively with the two parts, to be offset relative to each other. These discs are located between two stators formed with annular grooves, and one of the discs has a circular series of passages which extend over a mean radius the value of which is between the values of the mean radii of two circular series of passages provided in the other disc.

Assisted steering device for a vehicle

A hydraulic control system for a brake device comprises independent first and second brake circuits, the first circuit communicating with a first chamber pressurized by movement of a master piston actuated by a brake pedal, and the second circuit communicating with a second chamber whose pressure is dependent on that of the first and is developed by an assistance circuit, the second chamber being separated from the assistance circuit by a piston.

Hydraulic control system for brake device

The invention provides an assisted braking device which operates in conjunction with a brake pedal disposed at one end of a brake lever. The device comprises a master piston and cylinder assembly the piston of which is interconnected with the piston of an assisting jack by means of a connecting element on which is articulated the brake lever. The end of the brake lever remote from the brake pedal acts on a distributor adapted to feed the assisting jack with assisting hydraulic pressure so that when a force is applied to the brake pedal and thereby to the master piston via the connecting element, the distributor directs hydraulic fluid under pressure to the assisting jack, the piston of which then applies an assisting force to the connecting element.

The invention relates to a power-assisted steering arrangement in which the power-assisting mechanism is controlled in response to a limited relative angular movement which takes place between two parts of a control element such as a steering column. According to the invention, a coupling interconnecting the two parts in a manner which provides the limited angular displacement comprises external teeth formed on the two adjacent ends of the parts, and a connecting part such as a sleeve, or a disc with a central bore, which is provided with internal teeth which engage the external teeth of the two parts. A limited amount of play is present between the internal teeth and one or both sets of external teeth to provide for the relative angular displacement of the two parts.

The device comprises a master piston and cylinder assembly the piston of which is interconnected with the piston of an assisting jack by means of a connecting element on which is articulated the brake lever. The end of the brake lever remote from the brake pedal acts on a distributor adapted to feed the assisting jack with assisting hydraulic pressure so that when a force is applied to the brake pedal and thereby to the master piston via the connecting element, the distributor directs hydraulic fluid under pressure to the assisting jack, the piston of which then applies an assisting force to the connecting element. In the improvement of the invention, an abutment surface is provided for the brake lever located between the articulation point of the lever and its point of contact with the distributor so as to increase the mechanical advantage of the brake lever in the event of failure of the assisting hydraulic system.

An assisted braking device comprises a master cylinder and piston for applying the brakes. Depression of a brake pedal is arranged to move the master piston and to control brake assisting means to assist in the movement of the master piston. The assisted braking device is arranged such that if the brake assisting means is defective a driver can still effectively displace the master piston by applying the brake pedal. In this respect a safety rod is connected between a pedal lever of the brake pedal and the master piston independently of the brake assisting means and is arranged to be actuated if the assisting means break down.

An assisted braking device comprises a master cylinder and piston assembly the piston of which is connected to the piston of an assisting jack by an axially aligned interconnecting element. A brake pedal is adapted to operate the interconnecting element by a thrust member and a lever which is articulated to the interconnecting element and connected at one end to the thrust member; the other end of the lever acts on a distributor which can direct hydraulic fluid under pressure to the existing jack. A force on the brake pedal is transmitted via the thrust member and the lever to the interconnecting element to displace the master piston, and the end of the lever acting on the distributor simultaneously energizes the assisting jack. Safety abutment means which operate in the event of failure of the assisting hydraulic pressure allow displacement of the master piston by the force directly applied through the thrust member.

A power assisted steering mechanism comprises a steering column in two parts which are connected by a plain cylindrical torsion bar which may be solid or hollow and which allows a certain degree of relative angular displacement. An abutment is also provided to prevent excessive relative angular displacement resulting from failure of the torsion bar. The torsion bar has one of its ends bonded to one of the parts in any relative angular position and the other end is bonded to the other part as by welding, brazing or adhesive bonding, and a power assistance means are adapted device operates in response to relative movement of the parts resulting from a steering movement.

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Fosses, France

Jean L Dauvergne