Abstract: The invention relates to a pneumatic operating unit for compressed air brakes including a housing having at least one exterior compressed air connection device and at least one air-carrying connection. The operating unit further includes at least one piston, at least one piston rod, at least one valve body, at least one valve seat and at least one cylinder body fitted into the housing. The at least one cylinder body has at least one transverse connection and includes one or more of the at least one piston, valve seat and body. The at least one cylinder body also includes a seal in an axial direction between two transverse connections with respect to the housing so that the transverse connections are sealed off with respect to one another.

Abstract: Electropneumatic control valve for a pneumatic brake system of a vehicle having a relay valve housing (1) in which an axially adjustable control piston (5) is arranged for actuating a valve seat arrangement (8) which switches the compressed-air flow between at least one exterior brake line connection (11), a supply pressure connection as well as a bleeder connection (13), the control piston (5) being axially guided by means of a coaxial guiding arrangement and being capable of being acted upon by way of at least one electromagnetic pilot valve (6) for the axial adjustment, which pilot valve (6) is accommodated in a pilot valve housing (2) connected with the relay valve housing (1), in which case the guiding arrangement of the control piston (5) according to the invention comprises a separate guiding sleeve (17) which is stationarily fastened to the pilot valve housing (2) and which is provided with an upper guiding section (19) which, for the axial guidance, corresponds with a passage bore (18) in the control

Abstract: The underlying idea of the invention is to reduce the pressure force resulting from the inlet pressure and the outlet pressure of the back-up valve and affecting the valve body of the back-up valve. The valve body is a switching piston with a first and second switching piston side. The first switching piston side is pressurized by brake operating valve pressure or with brake cylinder pressure and the second switching piston side is pressurized on a first partial surface with brake cylinder pressure and on a second partial surface with brake operating valve pressure. The pressures affecting both sides of the switching piston thus cancel each other out.

Abstract: A high reliability and low power consumption anti-lock brake system is disclosed in the present invention. The two pilot valves in the present invention are controlled so as not to be energized concurrently. The secondary battery of the anti-lock brake system is charged by power supply and/or generator. An electric double layer capacitor comprising a housing made of functionally graded aluminum—ceramic material is used as the secondary battery.

Abstract: A trailer ABS diagnostics display system utilizes an output device to communicate specific ABS diagnostics information to a user located within the tractor cab in the form of ON-OFF code data. The system preferably includes wheel velocity sensors, at least one brake pressure modulator, an output device, a user interface which generates a user request signal, and an electronic control unit that is connected to the wheel velocity sensors, the brake pressure modulator, the output device, and the user interface. The electronic control unit generates the ON-OFF code data which is indicative of a diagnostic condition in response to the user request signal. The ON-OFF code data is transmitted to the output device for communication to the user located with the tractor cab.

Abstract: A valve arrangement includes an operating valve arrangement in the form of a relay valve and a control valve arrangement. The control valve arrangement includes a controlled inlet valve and a controlled outlet valve. Solenoid valves are provided for selectively routing pressure medium. A first control piston and a second control piston, which can be subjected to pressure by a pressure medium via operation of the solenoid valves, control actuation of the inlet valve and the outlet valve of the control valve arrangement. The control valve arrangement is installed directly on the housing of the operating valve arrangement to achieve a compact structural unit and to reduce the amount of pressure medium channels and pressure medium connections required. The operating valve arrangement and the control valve arrangement are designed such that parts of the control valve arrangement are located in, or constituted by, the operating valve arrangement.

Abstract: A single check manifold is provided for use with a trailer pressure control module in an electronically controlled braking system. The manifold has a valve body defining three distinct chambers. Two of the chambers communicate with air reservoirs and the third chamber communicates with the other two chambers and the trailer pressure control module. Separate elastomeric ball members serve as independently operating check valves for the individual pneumatic supply lines extending from the primary and secondary reservoirs that provide pressurized air for the trailer brakes and auxiliary devices associated therewith.

Abstract: A pre-engagement unit for a braking pressure modulator for a pressure regulating circuit includes a first pneumatic inlet, a second pneumatic inlet, a first pneumatic output terminal, and a second pneumatic output terminal. The unit includes an electrically actuated valve system having a plurality of solenoid valves and a plurality of electrical terminals connected to output terminals of an electronic control unit. An electric braking command signal transmitter delivers a driver initiated electric brake value setting to an input of the electronic control unit. Under normal conditions, a supply pressure and a redundancy pressure are delivered at the first pneumatic output terminal to be converted by an air quantity augmenting relay valve to a braking pressure. In case of failure of the electronic braking system, the redundancy pressure is delivered at the first pneumatic output terminal to be converted by the air quantity augmenting relay valve to the braking pressure.

Abstract: In order to solve the problem of the passing of an elbow piece (15) with a right-angle bend (16) through an opening (21) in a seal (19), said seal (19) is provided with a deformable slot (20). The tightness of the system, consisting of the seal (19) and the elbow piece (15), results from the existence of fir-branch shaped protrusions (27) on the base (26) of the elbow piece (15).

Abstract: A modulator relay valve assembly for selectively controlling brake application to an associated brake chamber is provided. The modulator relay valve assembly comprises a housing having a supply port, a delivery port, a control port, and an exhaust port. A piston is received in the housing defining a control volume in communication with the control port and is movable to control communication among the supply, delivery, and exhaust ports. A quick release valve with a direct passage to atmosphere communicates with the control volume, allowing contaminants to be expelled form the control volume during service and ABS braking. The quick release valve is biased toward an open position allowing communication from a control volume to atmosphere during service brake and ABS brake applications to decrease a pressure exerted by the control volume on the piston.

Abstract: The underlying idea of the invention is to reduce the pressure force resulting from the inlet pressure and the outlet pressure of the back-up valve and affecting the valve body of the back-up valve. The valve body is a switching piston with a first and second switching piston side. The first switching piston side is pressurized by brake operating valve pressure or with brake cylinder pressure and the second switching piston side is pressurized on a first partial surface with brake cylinder pressure and on a second partial surface with brake operating valve pressure. The pressures affecting both, sides of the switching piston thus cancel each other out.

Abstract: The invention relates to a pneumatic operating unit for compressed-air brakes, having a housing, having at least one piston, having at least one piston rod, having at least one valve body, having at least one valve seat, that housing having at least one exterior compressed-air connection device.

Abstract: A pneumatic servobrake having a detector (13) for the measurement of the pressure in a front chamber (1). The detector (13) has a baseplate (14) that is situated opposite an opening (25) in a wall (26) of the front chamber (1). A yoke-forming cage (38) that is placed over the opening (25) has an opening (40) that is traversed by a pressure sampling tube (16). The tube has a collar (41) that is retained between the cage (38) and the baseplate (14). An adapter (23) connected to the wall (26) urges the tube (16) against the cage (38) to allow for both a sideways motion (20) and a tilting motion (21). The lower part (31) of the tube (16) is fitted with an O ring (33) to establish a sealed pneumatic connection between the tube (16) and baseplate (14) such that a first sensor (15) is isolated from a second sensor (48) in a measurement of pressure in the first chamber (1).

Abstract: A pre-engagement unit for a braking pressure modulator for a pressure regulating circuit of an electronic braking system includes an electrically actuated valve system with three substantially identical 2/2-way solenoid valves. First and second terminals of the 2/2-way solenoid valves are selectively connected to the pneumatic inlets and output terminals of the pre-engagement unit, and to each other so that the first 2/2-way valve serves as an air admission valve for supply pressure, the second 2/2-way solenoid valve serves as an air admission/exhaust valve for redundancy pressure, and the third 2/2-way solenoid valve serves as an exhaust valve. Thereby, the pressure in the pressure regulating circuit can be increased, decreased, or maintained. Desirably, the first, second, and third 2/2-way solenoid valves are connected in parallel to each other.

Abstract: A two solenoid pressure modulated ABS relay valve incorporates a quick release valve in the control air circuit to allow a majority of the air in the control cavity to escape directly to ambient. The orifice through the exhaust solenoid need only handle a relatively small volume of air upstream of the quick release valve, i.e., between the quick release diaphragm and the inlet solenoid seat.

Abstract: A braking system for a wheeled vehicle includes a pressurized air source (63), an air actuated wheel braking device (51, 59), an operator control (49, 61) for commanding the supply of air to the braking device, an electronic control (19) which responds to vehicle speed and wheel speed to selectively invoking an antilock mode of braking. A control valve (37, 55) responds to the electronic control (19) and the operator control (49, 61) to selectively control the supply of air from the source to the braking device. In the antilock mode, the control valve is initially enabled to release braking pressure and thereafter alternately enabled and disabled to maintain braking pressure at a substantially constant reduced pressure, and subsequently alternately enabled and disabled at a reduced ratio of enabled duration to disabled duration to rebuild braking pressure.

Abstract: A self-cleaning feature is provided for a trailer ABS modulator. Direct exhaust is provided through the piston or diaphragm to establish control line and control volume drain capabilities. This provides for moisture removal from the control line or control volume. Quick exhaust during normal service braking is also improved and, likewise, exhaust during the ABS mode is improved.

Abstract: A full-function value for the tractor-trailer vehicle is provided with a unitary valve body enveloping service brake, pressure-protection, at least one solenoid, modulator and delivery pistons actuatable to be displaced between respective rest and operative positions within the body to provide a regular braking and ABS braking modes of the full function valve.

Abstract: A contaminant-ejecting relay valve for a pneumatic brake system is disclosed. Two embodiments of the valve are disclosed: in one embodiment, the valve is actuated by pilot air pressure, which is either supply air pressure or control air pressure; in another embodiment, the valve is solenoid-actuated. In both embodiments, the valve comprises a housing enclosing a chamber; a control port in the housing in fluid communication with the chamber; an exhaust port in the housing permitting removal of contaminants from the chamber; a main piston mounted within the chamber and movable between a first position and a second position; an exhaust passage through the main piston connecting the chamber and the exhaust port in fluid communication; and a blocking member movable between an open and closed position for opening and closing the exhaust passage, such that when the blocking member is in the open position it permits pressurized air from the control port to eject contaminants from the chamber.

Abstract: A compressed-air disk brake for vehicles comprises an actuating device for applying brake blocks in the direction of a brake disk and a brake cylinder, which, on arrival of the compressed air, initiates a braking action via the actuating device. At least one control module, comprising individual pneumatic and electronic components, is incorporated into the brake and/or the associated brake cylinder. For example, the control module may be formed directly on the brake cylinder housing section which encloses the ventilation chamber.

Abstract: A trailer control valve having control pistons for actuating a double seat valve, which can control the communication between a compressed air reservoir, a compressed air consumer, and a pressure relief location. In order to structurally simplify the trailer control valve, a control piston is provided that is jointly associated with an electrical control circuit and a pneumatic control circuit of a service brake system. Furthermore, a valve is provided that is connected to the pneumatic control circuit of the service brake system, which closes the pneumatic control circuit of the service brake off from to the trailer control valve when the electrical control circuit is functional, and in the event of a failure of the electrical control circuit, unblocks the pneumatic control circuit of the service brake system.

Abstract: A brake pressure control device is provided that includes a brake valve, an air master cylinder, and an air control valve. The air control valve is provided between the brake valve and the air master cylinder for selectively controlling the air pressure supplied from the brake valve to the air master cylinder. The air control valve includes an input port coupled to the brake valve for receiving air pressure provided from the brake valve; an exhaust port coupled to open air and to a back pressure chamber of the air master cylinder; an output port coupled to the air master cylinder; a pipe passageway coupled between the input port, the exhaust port, and the output port; at least one diaphragm provided within the pipe passageway; and a release valve connected between the exhaust port and the output port for releasing air pressure from the output port to the exhaust port during a brake releasing operation.