Abstract: A wheel braking cylinder and an expandable chamber of a pressure modulator are connected in a spatially closed arrangement that is connected to an operator controlled master cylinder, with the chamber being interposed between the braking and master cylinders. When vehicle deceleration reaches an upper threshold, an electromagnet is actuated and the armature thereof operates to isolate the master cylinder from the chamber and expands the chamber to reduce pressure in the braking cylinder, thereby reducing deceleration. When deceleration reaches a lower threshold the electromagnet is de-energized so that force generated by the armature biasing spring acts to reduce the chamber volume, thereby increasing pressure in the braking cylinder.

Abstract: A brake-slip-controlled brake system for automotive vehicles comprises a master cylinder (1) acted upon by the pedal force (F) in a direct or auxiliary-force-assisted manner and connected with the wheel brake cylinders in the vehicle wheels (VR, HR) e.g. via diagonally allocated hydraulic brake circuits 4, 5. The axial displacement of a rotating cam (32) is controlled by means of sensors (41-43) measuring the braking pressure, the axle loads, and the translational acceleration of the vehicle and feeding corresponding electric signals into an electric circuit arrangement (44). The cam (32) has bevelled control surfaces (48) and acts on braking pressure control valves (8, 9) by way of tappets.

Abstract: A pressure modulator for anti-skid systems in vehicle brake systems, including a plunger/cylinder assembly actuatable merely by supplying electrical auxiliary energy and in the form of a linear actuator is incorporated into a hydraulic or pneumatic pressure line between a master brake cylinder and at least one associated wheel brake cylinder in such a way that upon the onset of ABS functions a pump plunger is displaced by a linear motor action in such a way that fluid pressure arriving from the master brake cylinder is counteracted while the wheel brake cylinder pressure is simultaneously relieved. By appropriate design including a double check valve, ASR functions (anti-slip regulation) are also attainable, for which the pressure modulator can be mounted directly in an appropriately shaped housing recess of a brake caliper such as that of a disk brake.

Abstract: An auxiliary manual and physically controlled fluid pressure handling apparatus for vehicular pneumatic systems induced into the braking system to become a tool to aid the operator in providing rapid OFF-and-ON impulse or conventional braking, the selection of which is dependent upon the amount of force applied by the operator against the brake pedal, which also controls the frequency of intermittent application of the brakes by the apparatus.

Abstract: To monitor and control the pressure in the auxiliary pressure supply system of a hydraulic motor vehicle brake system, a circuit arrangement is employed which is provided with a door-contact switch (24) which closes when the driver's door of the motor car is opened and which at a pressure in the auxiliary pressure supply system (11-16) below the telltale threshold activates the hydraulic pump (11) irrespective of the activation of the ignition. Moreover, a holding circuit (25, 26, 30, D30) is provided through which, after closure of the driver's door, the hydraulic pump (11) continues to operate until the telltale pressure threshold or responding threshold is reached or exceeded.

Abstract: An antiskid control device including a main line system, a first oil hydraulic source generating a pressurized oil and supplying the oil to wheel cylinders through the main line system, a subline system, and a second oil hydraulic source generating a pressurized oil and supplying the oil to the wheel cylinders through the subline system. The main line system and the first oil hydraulic source are provided for a usual braking operation. The subline system and the second oil hydraulic source are provided for an antiskid control. The main line system has a cut-off valve which opens the main line system in the usual braking operation and closes the main line system in the antiskid control. The subline system has a switching valve which opens and closes the subline system according to a locking condition of the wheel during the antiskid control. The second oil hydraulic source generates a pressurized oil when a locking condition is sensed.

Abstract: The present invention concerns a control valve for use in a vehicle anit-lock braking systm adapted to control the application of pressurized brake fluid to at least one selected vehicle brake. The valve includes an outer housing having an inlet coupled to receive pressurized brake fluid from the vehicle master cylinder and an outlet coupled to supply pressurized brake fluid to the selected vehicle brakes. A passageway is formed in the housing for connecting the inlet to the outlet. A normally open isolation valve is located in the passageway and is utilized to control the flow of fluid through the passageway between the inlet and the outlet. When an incipient wheel lock condition is detected, the isolation valve can be closed to prevent a further increase in pressure to the controlled brakes and to hold the pressure supplied to the controlled brakes at a relatively constant level.

Abstract: A brake system provided for automotive vehicles comprises a braking pressure generator (3) and a braking pressure modulator (4) which is arranged in the pressure medium conduit leading to the rear wheel brakes (16, 17) and which allows to vary the apportioning of the braking pressure to the wheel brakes of the front and the rear axle to achieve approximation to an ideal brake force distribution in dependence on the instantaneous axle load. The braking pressure modulator (4) contains valve assemblies (5) serving to supply braking pressure alternately to the wheel brakes (16, 17) of the right and the left rear wheel in such a manner that one of the two rear wheels (HR or HL) furnishes the predominant portion of the brake force allotted to the rear axle. The pressure delivery alternates to connect to the other rear wheel on each braking operation or on each brake actuation or according to predetermined time criteria.

Abstract: This invention is a braking force modulator for hydraulic vehicle brakes which is intended to be inserted into the braking fluid conduit between the main cylinder or the like and one or more of the wheel braking cylinders and controlled by a sensor system for performing braking force modulation. The braking force modulator comprises a piston pump unit (12) with normally open inlet and outlet valves (37, 38) adapted to be closed under the action of a solenoid device (47, 48, 49, 52) whereby the unit is conditioned to act as a piston pump. The inlet and outlet valves (37, 38) are two mutually independent units adapted to be operated individually by one solenoid device each.

Abstract: An electropneumatic door control for vehicles is disclosed which consists of a pneumatic portion and an electronic portion. The electronic portion processes successive commands actuated by the vehicle operator to channel the signals to the pneumatic portion of the apparatus to activate alternate door openings and closings. Any blockage of the door movement is detected and signals processed to reverse the door closing or to halt the opening until the fault is corrected. The electronic portion also assures that the vehicle doors can only be opened after the vehicle has come to a stop, that when the vehicle doors are open the station or parking brake is held engaged, and that an audible warning signal sounds for a predetermined interval before the closing of the door.

Abstract: An auxiliary manual and physically controlled electronic-actuated air pressure handling apparatus for air-braking systems induced into the braking system to become a tool to aid the operator in providing rapid OFF-and-ON or conventional braking, the selection of which is determined by the road surface and the traction thereof.

Abstract: A recirculating pumping device for an anti-locking two-circuit motor vehicle brake system, with the pumping device including one pump piston provided for each brake circuit. The pumping device recirculates brake fluid released from the wheel brake cylinder or cylinders to a master brake cylinder during an anti-locking regulating or control process. The pumping device includes piston pumps, with one pump being provided for each braking circuit of the braking system. The piston pumps are constructed as free piston pumps having working chambers connectable periodically to a pressure source provided on the vehicle through a valve. The valve is switchable at a predetermined switching frequency or may be vented to the tank of the pressure source. The pistons are preferably constructed as stepped pistons, so that the recirculating pumping device may be adapted to the pressure level of a pressure source already available on the vehicle by an appropriate selection of a ratio between the piston surfaces of the pistons.

Abstract: The invention concerns a hydrodynamic torque transfer unit, particularly in the form of a hydrodynamic brake. Flow to the inlet of the working chamber of the transfer unit is controlled by an inlet valve movable between a closed, partially open and fully open position. A first piston moves the valve between its positions. A change over device cooperates with the first piston. The change over device includes a second piston. A first pressure chamber is defined between the first and second pistons. A second pressure chamber is defined behind the second piston. Initially, the first pressure chamber is pressurized, driving the first piston and thus the inlet valve to the fully open position. The second piston is moved by pressurization of the second pressure chamber to cut off pressure to the first pressure chamber and to instead cause communication between the first pressure chamber and the working chamber.

Abstract: An anti-locking system controls the service braking pressure for controlling the application of pneumatic braking pressure applied to a wheel vehicle. A valve responsive to the speed of the wheel causes actuation of a fluid pulse generator to generate fluid pulses of predetermined amplitudes and frequency to switch the braking pressure on and off when the vehicle wheel becomes locked.

Abstract: A safety-brake control system for a vehicle for the automatic actuation of the parking-brake valve to the brake-applied position comprising a lever arm connected at one end to the actuator of the valve and at the other end to a flexible connector element which in turn is connected to the moving arm of a solenoid. Energization of the solenoid pulls the flexible connector element to move the lever arm to actuate the valve to the brake-applied position. The valve thereafter can be actuated to the brake-released position by manual movement of the valve actuator.

Abstract: A modulator apparatus for use in a rotating member braking arrangement which has a fluid pressure responsive brake to which pressurized fluid is supplied for braking the rotating member, with the anti-locking modulator interposed between the brake and the source of supply of fluid pressure for cyclically decreasing and increasing the fluid pressure supplied to the brake. The modulator valving is constructed in such a way as to control the rate of rise of fluid pressure applied to the brake, thereby governing reapplication of braking forces by the brake and aiding in optimizing brake performance.

Abstract: An anti-skid power valve means for brake control apparatus, which valve means connects a pressure supply line to a wheel brake system, the valve means including a piston operably positioned in a chamber means, and a check valve means operably carried by the piston to cause flow of liquid from the wheel brake system to the pressure supply line when the piston is driven. Other means connect the pressure supply line to the wheel brake system and include a flow control orifice therein to permit by-pass liquid flow from the pressure supply line to the wheel brake system.

Abstract: To produce pulsating operation of vehicle wheel brakes in response to a continuous application of pressure to the brake pedal, a motor operated pressure switch controlled pulsating or pumping device is interposed between the brake master cylinder and the wheel brake cylinders of a hydraulic braking system. A ported piston within the pumping device is reciprocated and this action cyclically relieves pressure in the wheel brake cylinder lines and re-establishes braking pressure at a rapid rate of pulsation.

Abstract: A vacuum powered modulator for an adaptive braking system includes a housing that defines a chamber. The housing also includes an inlet that communicates with a conventional master cylinder and an outlet that communicates with a brake wheel cylinder and a valve for regulating the communication between the master cylinder and the wheel cylinder. A pressure responsive member is movably disposed within the housing chamber to define a first cavity and a second cavity. The first cavity communicates with a vacuum source and a passage through the housing communicates the second cavity with the first cavity so that the second cavity is also in communication with the vacuum source in a normal condition. When a skidding condition is imminent, a sensor is actuatable to close communication between the first and second cavity via the passage and to vent the second cavity to atmosphere so that the pressure responsive member moves to cooperate with the valve to reduce the communication to the wheel cylinder.

Abstract: A valve arrangement is provided for giving a continuous quick service facility in a triple valve controlling rail vehicle brakes in response to brake pipe pressure reductions. The arrangement comprises a pressure responsive member which responds to more than a predetermined brake pipe pressure reduction in relation to a reference pressure to operate a pulsator which discharges repetitive pulses of air from the brake pipe for as long as the pressure reduction persists.

Abstract: An apparatus for braking a rotating member which has a fluid pressure actuated brake cylinder for exerting force braking rotation of the member, a reservoir for supplying fluid to the actuated cylinder, a conduit for establishing operative communication between the actuated cylinder and the reservoir, and a sensor for detecting the rate of retardation of rotation of the member and for signalling the occurrence of a rate of retardation in excess of a predetermined rate, and an improvement in such apparatus in which a controllable anti-lock modulator is interposed in the conduit between the reservoir and the actuated cylinder for normally accommodating free flow of fluid between the reservoir and the actuated cylinder through the conduit and the modulator. The modulator is operatively connected to the sensor and responsive thereto for pumping fluid through the conduit in response to a signalled excessive rate of retardation and thereby for releasing braking force otherwise retarding rotation of the member.

Abstract: A master brake cylinder for two-circuit brake systems of motor vehicles which includes two cylinders and pistons for the two brake circuits arranged one behind the other in a tandem arrangement; the piston for the front axle brake circuit thereby has a larger diameter than the piston for the rear axle brake circuit while the pressure space for the front axle brake circuit is connected with that of the rear axle brake circuit by way of a line in which a control valve is arranged that is controlled in dependence on the vehicle load.

Abstract: The invention relates to an anti-skid brake system for vehicles. The system shows a new-type sensor and a new brake pressure control device which is activated by the sensor when and for as long as is required. If necessary, the pressure control device produces brake pressure pulsations so that the vehicle's wheels will be intermittently braked. The amplitudes of these pulsations control a special pressure regulating valve depending upon the braking force being applied.The shown sensor controls and compares by electrical means the wheel angular deceleration with the vehicle linear deceleration and provides data signals when the decelerations deviate inadmissibly from one another.

Abstract: An antiskid device for air brakes comprising a modulator mounted in a pressurized air line connecting a brake valve to brake actuators, and a signal producing means adapted to produce a throttling electric signal and a pressure reducing electric signal whereby the speed of the wheels can be controlled and the slip rate of the wheels can be maintained at an approximate optimum level of 0.2.

Abstract: A vehicle brake system having a power booster coupled to a master cylinder for normally supplying fluid pressure to the wheel cylinders of the vehicle includes an anti-skid device comprising an actuator hydraulically connected in parallel with the power booster for applying brake pressure to the wheel cylinders independently of the power booster when skidding occurs. The brake system includes solenoid controlled valves responsive to electrical signals generated when skidding occurs and operative to interrupt hydraulic communication between the power booster and wheel cylinders while establishing hydraulic communication between the actuator and the wheel cylinders.

Abstract: An improved anti-locking control of the type having a conduit through which hydraulic pressure is applied, a valve interposed in the conduit for controllably interrupting and releasing the application of pressure and an oscillating mass-spring actuator for the valve. In accordance with one aspect of this invention, reduction in braking force is carried out in a series of steps. In accordance with another aspect of the present invention, oscillation of the actuator mass is substantially limited to no more than a maximum amplitude. In each instance, greater efficiency is achieved in the use of energy required for operation of the anti-locking control.

Abstract: A pressure control valve applicable to anti-skid devices in automobile vehicles is provided with two hydraulically independent fluid circuits. One circuit controls the actuation of vehicle's brakes and the other circuit controls the braking effect of the vehicle's wheels to avoid skidding of the vehicle. Both circuits are related through the functions of two pistons, one piston being for storage to serve as an intermediary between a control fluid and a spring which accumulates energy and work as a differential piston, and the other piston being for the main actuation of the valve. The axial movements of the pistons allow the brake circuit fluid to compress or decompress as well as to open and close a valve which connects the conventional brake circuit to the anti-skid system.

Abstract: Brake lock in a fluid operated braking system is automatically suppressed by a brake diminishing cylinder and piston unit between the master cylinder and at least one wheel brake cylinder. Spring pressure upon the brake diminishing piston is normally over-balanced by a backstop pressure which is monitored by a wheel sensor. When a brake lock is imminent the backstop pressure drops and causes shifting of the brake diminishing piston from a first position in which it connects the main cylinder with the wheel cylinder into a second position in which it disconnects the main cylinder from the wheel cylinder and lowers the fluid pressure in the latter. Timely restoration of the backstop fluid pressure is insured by electrical contact elements disposed on the brake diminishing piston and engageable with complementary electrical contacts on the brake diminishing cylinder and functional to cause increased backstop pressure to be applied.

Abstract: Apparatus for controlling a two-circuit brake system for motor vehicles with the aid of a controllable pressure reducing valve which reduces the pressure in the rear wheel brake circuit compared to that in the front wheel brake circuit and which includes a by-pass line between the pressure inlet from the master cylinder and the pressure connection to the rear wheel brakes which is controllable by a solenoid valve; the brake slippage at the front and at the rear wheels is thereby measured, the thus-obtained values are compared with each other, and the solenoid valve is then controlled by a pulse sequence as long as the brake slippage at the front wheels is larger by a predetermined value than that at the rear wheels.

Abstract: A valve unit for controlling air flow and braking pressure in the brake cylinder of a pneumatic braking system. The valve unit has an inlet and an outlet valve assembly each of which are controlled by a solenoid valve, which is in turn controlled by an electronic braking control system. In the inlet valve assembly there is a valve diaphragm which on one side is biased by one pressure to close the valve unit, and which on the opposite side is biased by two pressures to open the valve unit. The ratio between the areas affected by the respective pressures is selected in such a way that the brake cylinder pressure is raised in essentially constant steps.

Abstract: The modulator of an antiskid device for air brakes of the type wherein a throttling electric signal is produced to change the braking pressure applied by brake actuators from a rapid increase state to a slow increase state before the braking pressure reaches a pressure increase target value, a pressure reducing electric signal is produced by rapidly decrease the braking pressure when the braking pressure has reached the pressure increase target value, and a throttling electric signal is produced again to change the braking pressure from the rapid decrease state to a slow decrease state before the braking pressure reaches a pressure decrease target value comprises a first solenoid assembly, a second solenoid assembly, a first pilot valve assembly, a second pilot valve assembly and a main valve assembly.

Abstract: The modulator of an antiskid device for air brakes mounted in a pressurized air line connecting a brake valve to brake actuators comprises a first valve which can move between an open position in which it allows pressurized air from the brake valve to pass freely therethrough and a throttling position in which it allows the pressurized air to pass therethrough in a reduced quantity, a second valve connected in series with the first valve and capable of moving between an open position in which it allows the pressurized air from the first valve to pass freely therethrough and a discharge position in which it permits pressurized air from the brake actuators to be discharged therethrough, a first air operating means for operating the first valve and a second air operating means for operating the second valve.

Abstract: A vehicle brake system comprises an actuator which is hydraulically connected in parallel with a power booster between the master cylinder and wheel cylinders of a vehicle. The hydraulic connections include solenoid control valves normally operative to connect the power booster to the wheel cylinders and to disconnect the actuator from the wheel cylinders. The valves are responsive to electrical signals generated when vehicle skidding occurs to disconnect the power booster from the wheel cylinders, to connect the actuator to said wheel cylinders, and to supply a pulsating fluid pressure from the actuator to the wheel cylinders in place of the steady fluid pressure normally applied to the wheel cylinders from the power booster, thereby to stop the skid.

Abstract: A motor vehicle wheel engages a gear which drives a multistage cam which actuates a system of hydraulic valves and pistons. A pressure-sensitive spool valve detects when the hydraulic pressure in the brake system exceeds the value which causes the wheel to enter the skid mode. The hydraulic pressure from the brake system passes through the pressure-sensitive valve to the system of hydraulic valves and pistons operated by the cam. The outlet of the hydraulic valve and piston system goes to the brake cylinder in the wheel. During the skid mode, a valve in the hydraulic valve and piston system closes and a cam action on one of the pistons in the system causes a pumping pressure to be applied to the brake cylinder. This anti-skid device further includes two fail-safe features to protect against system failure.

Abstract: A method of braking a vehicle having an antiskid brake circuit of the type having a modulator of which the modulator chamber is connected to a set of brake actuators, and a plunger projecting into the chamber, the plunger being moved by way of a driving assembly operated by a motor driven by an antiskid control device, responsive to rotary motion of the vehicle. The curve ploting the variation with time, in the volume of the modulation chamber from the position of maximum penetration by the plunger follows substantially the same course as the absorption curve for the set of brake actuators connected to the modulator. This absorption curve represents the increase in pressure in the brake actuator as a function of the increase in the volume of fluid contained in the brake actuator.