Abstract: An anti-lock braking system for a two-axle all-wheel drive vehicle having two intra-axle differentials and an engageable central inter-axle differential comprises a wheel sensor associated with each of the wheels for determining the rotational behavior of each of the wheels, and a four-channel electronic control circuit for providing individual wheel regulation. The electronic control circuit also detects whether the central differential is engaged or not and whether a malfunction has occurred in one of the channels. If one of the regulating channels has a malfunction and the central differential is not engaged, the electronic control circuit switches off regulation only in the malfunctioning channel. If, however, the central differential is engaged when a malfunction in one of the regulating channels has occurred, then the electronic control circuit switches off both the malfunctioning channel as well as an intact channel associated with a diagonally opposite wheel.

Abstract: A known brake circuit comprises a mechanical brake-pressure control device and an electrical brake-pressure control device. The mechanical brake-pressure control device is furnished for assuring an emergency operation in case of a fault of the normally predominance-taking electrical brake-pressure control device. The known brake circuit can be controlled only then in a load-dependent way, when both the mechanical as well as the electrical brake-pressure control unit comprise a load-dependent automatic brake-pressure controller. According to the invention, a restraining device (103 3, 5) is furnished in the mechanical brake-prerssure control device (103 3, 5). The restraining device (3) allows for passage of the brake pressure, set in the mechanical brake-pressure control device (103 3, 5), only in case of a fault in the electrical brake-pressure control device (106 6, 9, 12, 13).

Abstract: A safety circuit (12) for the surveillance of the proper functioning of an electronic wheel lockup-protected motor vehicle brake system includes automatic control circuits (10, 38), automatically controlled magnet valves (4, 46), and pick-up transducers (3, 47) at the motor vehicle wheels (2, 48) to be monitored. An error message and/or a partial shut-off of a defective pair of circuits, relating to wheel lockup protection circuits relating to diagonally disposed wheels, occurs in this safety circuit when an upward jump or a downward jump is recognized in the measured velocity of the one wheel and, simultaneously, the speed of the diagonally, oppositely disposed wheel or of any other wheel is measured to be above a limiting value. It is thereby avoided that an undesired error message occurs already when a jump in velocity is recognized, for instance in case of a standing vehicle, in case of a starting of the motor, or in case of a beginning of rolling of the vehicle.

Abstract: An overload warning system for a trailer brake cylinder of a trailer brake system having a nominal deceleration rate. It has been found that previous temperature sensing overdue warning systems have a disadvantage that undue delay occurs and that no warning signal is initiated until after damage to the trailer brakes occurs. The present invention proposes that the tractor brake system and the trailer brake system compare their received operating control signals from which they form a ratio factor and then produce a warning signal when the ratio factor changes beyond a predetermined critical change velocity. The present invention employs the rapid drop in braking force caused by a brake overload and uses the rapid drop and increase brake demand for readjusting the brake deceleration. The present invention is used for uniquely recognizing the "Fading" effect of the trailer brake system.

Abstract: The present invention provides a method of and an apparatus for regulating an electrically regulated brake circuit of a multi-circuit brake mechanism with pressure medium activated brakes. To decrease the expense of such multi-circuit brake mechanism, the invention transforms the pressure, modulated by the brake actuating mechanism, to an electrical signal and regulates or co-regulates the electrically regulated brake circuit (II) by this electrical signal.

Abstract: This invention provides an anti-lock and/or an anti-slip apparatus for commercial-type vehicles, in which there is a front axle and two live rear axles. The apparatus includes an electronic system as part of the anti-lock and/or anti-slip system. Such electronic system is preferably a four-channel system. To improve the quality of regulation during acceleration and braking, there is an additional speed sensor for the direct or indirect monitoring of the angular velocity of the cardan shaft. The electronic system determines whether the rotational speed of the cardan shaft varies from the average speed of the monitored wheels (vehicle reference speed). If a variance is determined, the electronic system activates measures for an alarm indicator, the regulation of the retarder acting on the drive train and/or for the synchronization and subsequent locking of the longitudinal differential.

Abstract: An apparatus for generating a signal, dependent on the weight of an object, is provided for an air-suspended vehicle. Control processes of the air-suspended vehicle with automatic levelling control unit correct road conditions, such as, for example, curve inclinations, influencing the suspended weight. According to conventional apparatuses, the suspended weight is determined by the measurement of the pressure in the air suspension. This requires additional measurement and signal transfer means. The invention apparatus is to generate a signal corresponding to the suspended weight under use of the distance values stored in the automatic levelling control unit. The automatic levelling control unit (8) is structured such that it generates during automatic control an additional signal, dependent on the temporary change of the distance value. The additional signal serves as the signal dependent on the suspended weight.

Abstract: A control valve device is provided for a pneumatically-operated vehicle brake system equipped with an antilocking device. The control valve has a controlled inlet valve and a controlled outlet valve. A pressure medium outlet chamber may be connected to a pressure medium inlet chamber by the inlet valve and to atmosphere by the outlet valve. The pressure medium inlet chamber is divided into a first sectional chamber connected to the inlet valve and a second sectional chamber connected to the pressure medium inlet. The first sectional chamber and the second sectional chamber can be connected through an additional valve device acting as a check valve which can be moved into an open position in a direction of the first sectional chamber. In this manner, it becomes possible to achieve a pressure reduction by not directing the reflux of the pressure medium from the pressure medium outlet chamber through the pressure medium inlet chamber, but instead through the outlet valve directly to atmosphere.

Abstract: A circuit for the surveillance of the switching state of a power transistor is constructed such that both, the voltage applied to the power transistor (1) is surveyed by way of a voltage comparator (7), as well as the voltage applied to the load (3) is surveyed by way of a further voltage comparator (8). The comparator (7) in the switched-on state and the comparator (8) in the switched-off state are activated by the input signal (U.sub.IN) of the power transistor (1). The output signals of the two comparators (7, 8) are combined to a status signal (U.sub.Stat). It is possible by way of the proposed circuit to recognize both a short circuit or, respectively, a shunt circuit of the load as well as a leakage current of the power transistor (1) and thus an interruption of the load occurs.

Abstract: An apparatus for the generation of compressed air is disclosed, where the supply of air from the compressor (1) to the user (6) is interrupted in case of preset user-side pressure. This apparatus prevents a freezing in case of low ambient temperatures in the pressure lines in which condensed water has formed. A temperature sensitive switching device (14, 29) responds to the actual ambient temperature. The switching device (14) does not stop the compressor (1) in case of a preset user-side pressure and in case of a falling below of a preset ambient temperature. The compressor (1) carries then the warmed-up air through a region of the device before discharging it into the surrounding atmosphere. The device is particularly suited for compressed-air generation plants in motor vehicles which are adapted to be used in cases of low ambient temperatures.

Abstract: A valve vane is provided, where the valve vane is movable along the surface of a casing part and is driven by a dog follower, guided in a slot of the casing part, wherein the slot is furnished at least at one end, and wherein a flat slider is required for a sealing of the casing part. Such a flat slider requires by itself a substantial structure. The invention valve vane (6) is structured such that it covers the slot (12) in each phase of its motion. The invention structure is particularly suitable for being employed in a inlety valve system of a compressor.

Abstract: A method for the approximate determination of the average temperature of a device component of a brake device. The average temperature is determined by the deformation of the device component at the start of a brake actuation and at a point in time t.sub.1 following said start as well as by a temperature-dependent change of the elasticity module of the material of the device component. The method is particularly useful for surveillance of brake devices of vehicles with respect to overloading and fading.

Abstract: A strain relief device for an electrical cable disposed in a cable lead-through system for a housing containing an electrical component. The housing includes a cup-shaped housing portion and a closure portion. The strain relief includes two opposingly moving elements for clamping the cable. The two elements of the strain relief are braced against an inside wall of the cup-shaped housing portion. The closure portion is formed by one of the two elements of the strain relief.

Abstract: An automatic level control device for vehicles is furnished with an electrically triggered shut-off valve (44). The shut-off valve (44) can be loaded with a pressure in closure direction corresponding to an air-suspension pressure. The force to be exerted by the electrical actuation device (23) for opening of the shut-off valve (44) is independent of the closure pressure loading the shut-off valve (44). The device components of the electrical actuation device (23) of the shut-off valve (44) can be furnished of small volume size and the passage cross-section of the shut-opff valve (44) can be formed of relatively large size. The device serves for automatic level control devices for vehicles.

Abstract: A device for changing the pressure in tires of a motor vehicle. The novel device achieves that the venting of the tires can be performed independent of throttling. The device includes a tire-pressure control valve (1) with a pneumatic connection terminal (8). A control element (10) is chargeable via the pneumatic connection terminal (8). The control element (10) is formed as an actuating piston, for actuation of the valve device, comprised of valve seat (5) and closure body (6), against a restoring force, furnished by a valve spring (7), into the open position by the pressure of the compressed-air source. The device can be retrofitted into the conventional tire-pressure control device systems.

Abstract: The present invention provides a dual-circuit hydraulic brake system, which has a hydrostatic circuit and a servo circuit. The brake system also has an electronic anti-locking system, which is fed by the servo circuit. To cut off the master cylinder in case of a controlled braking and thereby to guarantee a closed circuit, an annular receptacle in the servo cylinders used for circuit separation is connected to a volume receptacle in case of a braking controlled by the anti-lock system. At the sametime, the master cylinder is cut off by means of a central valve.

Abstract: This invention provides a servo cylinder and a power brake for an anti-lock hydraulic brake system. It enables elimination of a cutoff valve in the static circuit for anti-locking operation and at least compensates for a brake pressure component produced in the servo cylinder by the static control pressure by providing an oppositely directed dynamic control pressure independent of the anti-locking system.

Abstract: A printed circuit board provided for mixed-component assembly of electrically hard-wired and surface-mounted components which eliminates the difficulties of bonding large components and which alleviates thermal shock and stress during the soldering of the contacts by a flow bath process. The printed circuit boards for mixed-component assembly are capable of utilizing PLCC components which, in many cases, are difficult to mount on a printed circuit board. The printed circuit board includes at least one recess for receiving and holding a PLCC component. The sides of the recess are provided with conductive indentations which serve to guide the PLCC component during insertion and which provide soldering points for electrical connections.

Abstract: A valve including a housing in which is disposed a relay piston. The relay piston has an upper control surface adjacent a control chamber leading to a control connection. The underside of the relay piston is in communication with a reaction chamber leading to a working pressure connection. An outlet valve seat is formed on the lower extremity of the relay piston. A multistage hollow graduated piston disposed within a graduated bore formed in the housing. The graduated piston has a tapered edge extending downwardly to form an inlet valve seat. A hollow valve element is cooperatively associated with the inlet and outlet valve seats to form inlet and outlet valves. The underside of the graduated piston a reaction chamber which is connected to a second control pressure connection.

Abstract: This invention provides an apparatus for transmitting a driving force between two components. The apparatus utilizes a cover rotatably mounted in a housing such that, as a result of engagement between the cover and a first component, a rotation of the cover corresponds to a displacement of such first component. The first component drives a second component by means of an actuator.