Abstract: To maintain stability of operation of a vehicle entering a curve, for example with excessive speed upon entering the curve, and application of the vehicle brakes by the operator, the braking effort (P.sub.HA) applied to the rear wheels or rear axle of the vehicle is controlled to be at a low and constant level, substantially below the braking effort (P.sub.VL, P.sub.VR) applied to the front wheels of the vehicle, and for a limited period of time (t), which may be a predetermined time duration, under control of a timing element (4), or which may depend on counted braking cycling events, of braking effort applied to the front wheels, for example under control of an anti-brake locking or blocking system (ABS). For example, a counter (8) may count two cycles of operation of the ABS and then release the low, constant braking effort phase applied to the rear wheels of the vehicle. Stability of operation of the vehicle, in the curve, is thus maintained.

Abstract: A brake system having a master cylinder including main pistons, a brake booster for displacing the main pistons a brake valve for controlling the brake booster and a pressure supply device. The brake booster has a booster cylinder and a booster piston which is displaceable into the booster cylinder. The booster piston divides a booster chamber from an auxiliary chamber, which is located between the booster piston and the master cylinder. A first valve assembly and a second valve assembly are provided. The second valve assembly is located between the pressure supply device and the brake valve as well as a connection associated with the booster chamber. The first valve assembly is intended for relieving pressure in the booster chamber in favor of a return line or to join it with the pressure supply device. In the anti-skid mode, pressure in the booster chamber is initially reduced by means of the second valve assembly.

Abstract: A method and a multi-circuit brake booster for feeding back disruptions of any arbitrary kind, even of an associated anti-skid brake system, to a then-changed brake pedal characteristic, the influence on the brake valve triggering being effected via a travel simulator device. The transmitting member in the travel simulator device is a travel simulator spring enabling a predetermined idle pedal travel, and this spring responds whenever, in response to an arbitrarily generated disruption signal, a lockable storage element assumes its other position and mechanically engages a transmitting member in the chain from brake pedal actuation to brake valve slide actuation in an arresting manner. Upon reaching a predetermined amount of biasing, as a result of the further compression of the travel simulator spring, the opening of the brake valve then takes place abruptly, with a corresponding increase in brake pressure and a corresponding increase in vehicle deceleration.

Abstract: A wheel anti-blocking control system (ABS), in which, subsequent to a brake pressure drop, the first brake pressure rise pulse .DELTA.P.sub.2 is controlled, in dependence on the preceding brake pressure drop (.DELTA.P.sub.1) and on a quotient defined by the relationship: ##EQU1## in which +.omega..sub.m and -.omega..sub.m are representative of maximum angular acceleration/deceleration of the respective wheel being controlled and .alpha. is a factor somewhat less than unity, and which may vary in dependence on the direction of movement of the vehicle, for example whether the vehicle is moving in a straight path or is moving along a curve. If moving along a curve, so that angular acceleration is involved, the factor .alpha. is reduced.

Abstract: A brake booster having one open and one closed brake circuit, in which a tight partition penetrated by a pedal tappet extension is disposed between the two pressure chambers of the brake circuits. During normal braking, the pressure distribution from the open brake circuit to the closed brake circuit is effected via a magnetic valve capable of being switched over for the initiation of ABS regulating functions, so that it is possible to realize a simultaneous control of pressure in both brake circuits for both normal braking and for the realization, by the simplest means, of ABS functions is possible.

Abstract: A vehicle having wheels driven via a differential transmission, non-driven wheels and wheel brakes individually associated with the wheels and having wheel brake cylinders has an apparatus for reducing drive slip between the driven wheels and a road surface located beneath these wheels. The apparatus includes a control unit, which is connected to angular velocity wheel sensors for rotational wheel angle associated with the wheels and has at least one differentiating device, which emits control signals whenever drive slip exceeds a preselected switching threshold. By using the control unit, brake pressure control valves of the slipping wheels are controlled such that brake pressure in their wheel brakes builds up (P2). The pressure buildup is terminated as soon as the differentiating device ascertains that a drop of the angular wheel accelerations have dropped below a maximum value. Subsequently the brake pressure initially remains substantially constant.

Abstract: A system for supplying fluid under pressure for a motor vehicle brake system having a pressure supply system including which has a pump, a pressure reservoir, a reservoir pressure switch connected to the pressure reservoir for switching the pump on and off, and a check valve disposed following the pump, and a brake control valve connected to the pump and the pressure reservoir for directing fluid braking pressures into at least one brake circuit which has at least one wheel brake. Between the pressure reservoir and the brake control valve, there is a second check valve through which the pressure reservoir supplies the brake control valve with a pressure medium when the pump is not operating.

Abstract: To prevent undue low operating speed of an automotive vehicle engine if slippage of a driven wheel is sensed, the speeds of the driven wheels are sensed, and, when one of the driven wheels first exceeds a reference level, a braking effort is applied thereto, the other wheel, however, being permitted to slip or spin until the other wheel has reached either a predetermined speed, at which it is then selectively braked, or the engine has reached a predetermined engine speed level (n.sub.min), after which time the other wheel then can also be braked, or the spinning decreases due to lesser power being applied by the engine.

Abstract: A hydraulic brake booster including main cylinders operative relative to a pedal stroke by which a sufficient pedal stroke is still available in the event of a failure in the pressure supply so that the brakes can be actuated by the pedal stroke and furthermore flooring of the brake pedal is avoided in the event of failure of the fluid medium power supply.

Abstract: A main brake cylinder for vehicle brake systems, in which a control valve effects the application of an auxiliary force to at least one brake piston. Additionally engaging the control valve and supplementarily for possibly adjusting the brake pedal is an arbitrarily actuatable final control element, which is triggered by electrical signals of any desired form and duration. As a result, a feeding of pressure into the brake circuit is effected independently of the brake pedal actuation and as a function of electrical control signals, as a result of which a multiplicity of further possible applications of such a brake valve are afforded, for instance in order to realize a drive slippage regulation, self-diagnosis as to tightness, function, output and pressure supply, and stepped braking.

Abstract: A pressure fluid reservoir comprising a cylinder with a reservoir connection, a piston displaceable in the cylinder and non-contact switch means for indicating piston positions. Between the reservoir connection and the piston, the cylinder encloses a pressure fluid chamber, which is intended for storing a pressure fluid such as hydraulic oil, brake pressure fluid or the like. Opposite the pressure fluid chamber, the piston defines a gas chamber. The non-contact switch indicating means comprise Reed contacts, for example, and are disposed outside the cylinder such that they are longitudinally adjustable along the cylinder. Adjustment is effected by a temperature-dependent adjusting means, embodied for instance as an expansion element. Permanent-magnet actuating means, for actuating the Reed contacts in a non-contacting manner are fixed in recesses in one side of the piston.

Abstract: A hydraulic dual-circuit tandem master brake cylinder intended for use in brake systems of motor vehicles is proposed, to which a closed brake circuit (I) and an open brake circuit (II), the latter reinforced by auxiliary pressure, are connected. In order to switch the control valve, the main brake cylinder has a foot-actuated push rod as an actuation member, with transmission of force via a control contour or a travel-limiting spring, and it furthermore has an auxiliary piston member near the pedal, this member having an effective surface for making the feedback of the brake pressure which has been established perceptible. In this manner, a small, compact master brake cylinder construction which is very favorable in price is created. It is furthermore of advantage that the pedal characteristic is designed optimally in terms of human engineering. The main cylinder can also be used at little expense for an anti-wheel-lock apparatus as well.

Abstract: To simplify the anti-lock brake system in which two brake circuits (I,II) are used, connected to diagonally located wheels (2,3; 1,4), magnetic valves are provided in which one braking circuit fully controls the wheels thereof and the wheels of the other braking circuits are controlled by a slave or follower valve system (9,10) which includes a biassed valve (10) controlling the braking pressure at the front wheel of the second braking circuit (1) with a difference pressure, so that the second slave control valve operates as a differential pressure control valve (10,32). The differential can be controlled as a function of absolute braking pressure, as sensed, for example, by a brake pressure piston (30) and a biassing spring (30a) therefor.

Abstract: To prevent erroneous operation of a wheel anti-skid or anti-brake lock system which is arranged to compensate for yaw of the vehicle if the wheels at the respective sides of the vehicle operate on portions of a road surface of widely different roughness, e.g. one side of the vehicle on a dry road track and the other side on ice or snow, upon movement of the vehicle through a curve during which a brake is applied, so that the yaw-prevention portion of the system might erroneously recognize movement through the curve as yaw, that is, rotation about a vertical axis through the vehicle, an accelerometer (36') is provided, connected to sense transverse acceleration of the vehicle, e.g. about a vertical axis, and inhibiting application of the yaw-preventing signals to the automatic braking system.

Abstract: A vehicle brake system including a brake force booster, controllable a brake pedal, for actuating a main brake cylinder in order to supply wheel brake cylinders with braking pressure for service braking operations and also includes brake pressure control valves, which direct braking pressures into individual wheel brake cylinders if there is a danger that the wheels will lock during braking. To this end, pressure is supplied to the brake pressure control valves from the brake force booster via controlled valves. In order to be able to reduce drive slip as well, the controlled valves are embodied as a switchover valve, so that pressure can be directed to the brake pressure control valves directly from a pressure supply container bypassing the brake force booster. The vehicle brake system is inexpensively further embodied for reducing drive slip by modifying the control valves.

Abstract: To prevent spinning of wheels in all-wheel vehicles, a traction control system is used which, in its simplest form, may use existing wheel speed sensors. If any one, or more, or all of the wheel speed sensors provide output signals representative of spinning of a wheel, for example by providing output signals representative of a substantially higher speed than other wheels, or higher than a reference--indicating that all wheels are spinning--an output signal is generated by the electronic control unit (6) which, in turn, controls application of the wheel brake to the respective wheel, thus preventing its spinning. Spinning of any one wheel, of course, causes loss of traction at another one due to the effect of the normally interposed differentials (4, 5, 3a).

Abstract: To prevent oscillation of a wheel being intermittently braked in an anti-slip or anti wheel block system, an increase of braking pressure, after a prior decrease, is controlled to occur during a first time interval which is short with respect to an oscillation period of the wheel if subjected to brake pressure pulses, so that the braking pressure increase will be small or short, e.g. about 3 milliseconds, comparable to stepped pressure increases after an initial wheel deceleration and permitted re-acceleration, the pressure then being maintained at an even level for an interval (T.sub.3) which, likewise, is short with respect to the intervals (T.sub.0, T.sub.4) between stepped increases. The respective time intervals can be controlled by individual, special pulse generators, or by suitable programming of microprocessor elements.

Abstract: A pressure control device, preferably for use in a control system of an automatic transmission of a motor vehicle, comprises a housing which accommodates a magnetic coil and an armature, and a control slide actuated by the armature and movable within a valve through which pressure medium to be controlled passes. A plunger carrying the armature is arranged coaxially to the magnetic coil within the housing and is supported at the both ends axially. A diaphragm spring is arranged at the end of the plunger facing toward the control slide. A pin loaded with the control pressure and arranged at the end of the control slide opposite to that facing the plunger acts on the control slide. A compression spring provided on the armature develops a force which acts against the force of the electric magnet and the hydraulic force which acts on the pin. The pressure control device is therefor suitable for controlling of considerably higher pressures and greater volumes of the pressure medium.

Abstract: A control unit (14, 60) controls the braking pressure (P) at the brakes or the wheels, at both right and left sides of an axle, in accordance with "select-low" and/or "select-high" mode. The system is improved by associating a pressure sensor responsive to braking pressure in at least one of the front wheels. The control unit (14, 60) is so arranged that, upon sensing a tendency to skid or block at the rear wheels (FIG. 3: t.sub.3), the pressure at the rear wheels is controlled to a lower level than that at which tendency to block had been sensed, and then a constant pressure maintenance phase is commanded at a predetermined pressure (P.sub.oHA) for an extended period of time (to t.sub.8), for example under control of a timing element (FIG. 2: 19) or until the pressure sensor determines that the braking pressure (P.sub.

Abstract: To provide for change in application of pressure rate, or pressure gradient, in a simplified control system, a group of shunt valves (36-39; 51, 52), which are normally open, are hydraulically connected in parallel to at least one of the brake fluid control valves (8-11; 43, 44, 45) which receive, hold, or drain pressurized brake fluid from main brake cylinders (2, 3) under command of an automatic braking system evaluation stage or unit (ABS) in accordance with sensed wheel speed, acceleration or deceleration, to apply additional pressurized brake fluid to the brake associated with the wheels. The brake fluid control valves (8-11; 43, 44, 45) include chokes, or have inherent choking action, in their hydraulic path which is bypassed by the shunt valves.