Fiat Societa Per Azioni

Fiat Auto S.p.a.

Centro Ricerche Fiat S.p.a.

Industire Magneti Marelli S.r.l.

Virginio Maggioni

Vittorino Torrielli

Renzo Moretti

Enrico Rivetti

Giuseppe Amedei

Carlo A Quilico

Giancarlo Michellone

Pierluigi May

Carmelo Gemmellaro

A throttle-controlled hydraulic power brake employing a pressurized fluid produced via a pump and preferably stored in an accumulator for enabling servo-assisted displacement of a push rod acting on the master cylinder of a brake pump (of the same type employed on vacuum-operated power brakes) subsequent to axial displacement of a second push rod controlled directly by the brake pedal. Displacement of the second push rod towards the first provides, against the action of elastic means, for opening a first face seal valve, which feeds the pressurized fluid into a variable-volume accumulating chamber, so as to displace a piston connected axially to the first push rod and defining a movable wall of the accumulating chamber, and so close the valve. Opposite displacement of the second push rod, on the other hand, provides for opening a second face seal valve connecting the accumulating chamber to a drain.

Throttle-controlled hydraulic power brake booster

A hydropneumatic suspension system having the characteristic of being able to vary at will, and independently of each other, the rigidity of the sustaining and load-adaptation means of each vehicle wheel, consisting of a series of sensors for measuring the dynamic attitude of the vehicle connected to a central electronic control unit, and respective hydraulic dampers of adjustable internal pressure, which support the wheels and are connected to respective hydropneumatic service accumulators the internal pressure of which is controlled by solenoid valves controlled by the central control unit; hydraulic energy can be supplied to the accumulators by, for example, the servo-steering system pump via a common main accumulator. (FIG. 1).

Hydropneumatic vehicle suspension system of variable attitude

An electromagnetically operated rotary servovalve particularly suitable for controlling hydraulic actuators, for example forming part of vehicle suspensions is described; the servovalve comprises a valve body provided with at least one series of respective radial ducts disposed angularly spaced apart, a rotary distributor of cock type which depending on its angular position either blocks said radial ducts or selectively connects them together in pairs, a pair of linear electromagnetic actuators, and transmission means mechanically connecting said electromagnetic actuators to said rotary distributor and arranged to convert with a predetermined step-up ratio the linear motion of said actuators into rotary motion of said distributor.

Electromagnetically-operated rotary servovalve

A fluid pressure device for operating the brake members of a vehicle with a wheel anti-locking function includes a fluid pressure actuator controlled by a control circuit including sensors arranged to detect the tendency of the wheels to lock, in order to interrupt the braking action. The pressurized fluid from, for example, the lubrication circuit of the engine and passing through a three-way solenoid valve piloted by the control circuit may act in the sense corresponding to activation or de-activation of the actuator, against the action of a resilient biassing member.

Fluid pressure device for operating the brake members of a vehicle with

An automatic timer valve for irrigation plant includes a tubular differential-area piston which defines respective major-diameter and minor-diameter chambers in a hollow valve body. The chambers normally communicate through the piston to allow water to flow interruptedly from an inlet to an outlet. A build-up of back-pressure at the outlet acts against the major face of the piston and, overcoming the inlet pressure, advances the piston against a spring to cause abutment of the shutter disc and an annular shoulder. This abutment cuts off the flow, with the exception of a restricted passage, and puts the outlet into communication with a drain outlet. When the pressure in the outlet drops, the higher relative pressure at the inlet displaces the piston in a reverse stroke and uninterrupted flow recommences.

Automatic timer valve for controlling the output of irrigation plant

A self-cleaning flow-regulating valve for an irrigation system has a displaceable element which is adjustable axially within a valve body by rotation of an external nut to adjust the position relative to two opposing seats of a floating bush which defines the size of a flow passage for irrigating liquid.

Self-cleaning valve for regulating the flow of liquid in irrigation

A control device for a pneumatic braking system which is particularly suitable for industrial trucks and lorries the axle loading of which varies widely depending on whether the truck is empty or fully laden. The device has an inlet port which in use is fed with the braking control pressure, and an outlet port which feeds a servo-valve to determine the pressure fed to the brakes of, for example, the rear wheels. The control device comprises a generally cylindrical housing separated into two chambers by a piston, the two chambers communicate with each other through a controlled restrictor passage the size of the opening of which is controlled by the position of the piston. The exposed area of the piston in one chamber is greater than in the other, so that when the pressure in both chambers is the same, the piston experiences a resultant force towards the other chamber but movement is resisted by a force proportional to the axle loading derived by a mechanical or fluid pressure arrangement. If the braking control pressure in the two chambers reaches a value such that the resultant force on the piston is greater than the applied force the piston moves partly closing the restrictor thereby reducing the pressure in the one chamber until the forces on the piston are balanced. The outlet port from the device is fed from the one chamber so that the outlet braking pressure is reduced with respect to the inlet pressure in these circumstances.

Control device for a motor vehicle pneumatic braking system

A fluid operated braking system for a motor vehicle, having a main braking circuit for applying braking pressure to the actuators of both wheels of at least one axle of the vehicle and a subsidiary braking circuit for applying a reduced braking pressure to one of the wheels of the axle if it should enter a skid or incipient skid state, in which the subsidiary braking circuit is controlled by two distributors each of which has three ports, one connected to the main braking circuit, one connected to the subsidiary braking circuit, and one connected to the brake actuator of an associated wheel of the axle, the distributor being controlled by an electrovalve to connect the main braking pressure circuit to the brake actuator of the associated wheel of the axle under normal condition and to connect the subsidiary braking circuit, through an internal path within the distributor to the brake actuator of one wheel of the axle when this wheel enters a skid or incipient skid state, without affecting the distributor associated with the other wheel of the axle. This internal path in the distributor includes elements which produce a varying resistance to the passage of fluid thereby permitting a gradually increasing brake pressure to be applied to the skidding wheel.

Fluid distribution valve for a motor vehicle braking system

A fluid operated braking system for a motor vehicle, having a main braking circuit for applying braking pressure to the actuators of both wheels of at least one axle of the vehicle, and a subsidiary braking circuit for applying a reduced braking pressure to one of the wheels of the axle if it should enter a skid or incipient skid state, in which the subsidiary braking circuit is controlled by two distributors each of which is associated with a respective wheel and has three ports, one connected to the main braking circuit, one connected to the subsidiary braking circuit, and one connected to the brake actuator of the associated wheel of the axle, the distributor being controlled by an electrovalve to connect the main braking pressure circuit to the brake actuator of the associated wheel of the axle under normal braking conditions, and to connect the subsidiary braking circuit, through an internal path within the distributor, to the brake actuator of the associated wheel of the axle if this wheel enters a skid or incipient skid state, without affecting the distributor associated with the other wheel of the axle.

Motor vehicle braking system

An improvement in pneumatic anti-skid braking systems for at least one wheel of a vehicle, of the type having a first valve system for causing a controlled reduction in braking pressure in a brake actuator upon reception of a control signal from an anti-skid control device sensitive to the dynamic state of at least one wheel of the vehicle, and a second valve system for causing a subsequent controlled rise in pressure after the signal from the anti-skid control device has been removed, the improvement being the provision of an accumulator in parallel with the first valve system and having two unidirectional valves, one at each side, which permit the accumulator to charge up to the braking pressure during normal braking, store this pressure upon anti-skid release of the braking pressure, and then deliver its charge to the circuit, causing a rapid increase of braking pressure after the anti-skid control signal is removed from the first valve system.

Growing community of inventors

Rosta, Italy

Virginio Maggioni