A method of brake control of a vehicle combination (2) composed of a tractor vehicle (4) with an electronically controlled braking system (5) and a trailer vehicle (6, 8) with a pneumatically controlled pneumatic braking system (7, 9), involves introducing the brake control pressure (p.sub.BC) of the trailer vehicle (6, 8) into a tractor brake control line (19) extending to a tractor vehicle-side brake coupling head (26) via an electronically controlled trailer control valve (13) of the tractor vehicle (4). At the beginning of a braking operation, a pressure pulse (34) exceeding a target brake control pressure (p.sub.BC_soll) is introduced into the tractor brake control line (19). The volume of a trailer brake control line (28, 29, 32) coupled to the brake coupling head (26) is ascertained, and the absolute value (p.sub.PI) and/or the duration (t.sub.PI) of the pressure pulse (34) introduced are/is established depending on the ascertained volume.

A braking system of a trailer and work machine includes a pressurized fluid supply, a hydraulic base valve fluidly coupled to the supply, and a pneumatic base valve fluidly coupled to the supply. A proportional control valve is also fluidly coupled to the supply, and it includes an outlet disposed in fluid communication with the inlets of the hydraulic base valve and the pneumatic base valve. The system further includes a hydraulic output configured to be fluidly coupled to a hydraulic braking system of a trailer, and a pneumatic output configured to be fluidly coupled to a pneumatic braking system of a trailer. The hydraulic output is fluidly coupled to the outlet of the hydraulic base valve, and the pneumatic output is fluidly coupled to the outlet of the pneumatic base valve.

A pneumatic arrangement for a braking system of a vehicle, the pneumatic arrangement comprising a manually controllable brake actuator, a trailer parking brake outlet connectable to a parking brake cylinder of the at least one trailer unit, a tractor parking brake outlet connectable to a parking brake cylinder of the tractor unit, a first valve arrangement, and a second valve arrangement, wherein the pneumatic arrangement is operable to assume a parking brake mode in which the first valve arrangement is controlled to arrange the tractor parking brake outlet in fluid communication with an air outlet, and the second valve arrangement is controlled to arrange the trailer parking brake outlet in fluid communication with the air outlet.

The invention relates to a pneumatic valve system (5) for a braking system of a towing vehicle. The pneumatic valve system (5) comprises a valve block (28) comprising a supply pressure inlet (29), a towing vehicle supply pressure outlet (30) and a towing vehicle control pressure outlet (32), as well as a control valve (6), a redundancy valve (7), and a brake valve (10). The pneumatic valve system (5) permits a redundant pressure supply of a brake cylinder of a parking brake of the towing vehicle by connecting the valves and the supply pressure outlet and outlets to one another in a very compact and stable manner.

An electropneumatic trailer control module (100) with a housing structure (100a) includes a manual brake pressure port (154) receiving a driver's brake demand pressure component, a spring-supported electropneumatic input valve (104) with at least two ports and being capable of switching between two positions (open or closed), and an electropneumatic brake pressure port (144; 146) for receiving an electropneumatic brake pressure component from at least one independent pressure source (138; 140), and a relay valve (112) having a control port (110), a supply port (114), an outlet port (116), and a relief port (118). The spring-supported electropneumatic input valve (104) is retained in an open position when there is no electronic activation of the spring-supported electropneumatic input valve (104).

A parking brake system for electrically controlling a parking brake of a vehicle is provided. The parking brake system includes a parking brake provided for each wheel, an air dryer controller, and an actuator. The air dryer controller is provided to an air dryer to electrically control the parking brake. The air dryer dries compressed air for use in the parking brake. The actuator is provided for each axle of the wheel to actuate the parking brake with the compressed air in accordance with an electric signal from the air dryer controller.

Method and apparatus for providing self-contained brake release capabilities in a tractor trailer to facilitate autonomous movement of the trailer within a controlled environment such as in a yard, depot or other facility. Pressurized air is stored in a reservoir of the trailer while the trailer is in a stationary, parked position. Upon receipt of a wirelessly transmitted brake release command, a trailer controller circuit transitions a flow valve to interconnect the reservoir to a brake assembly to apply pressure sufficient to release the brake assembly and enable rolling movement of a wheel assembly of the trailer. In this way, a yard shifter or other transport vehicle can mechanically engage and move the trailer without the need to provide pressurized air or electrical power to the tractor trailer in order to release the brakes. Security protocols can be used to ensure the brake release operation is performed under authorized conditions.

When a brake of a tractor is released, a control unit having a computer built therein monitors the pressure of working fluid output from a trailer control valve that controls a brake of the trailer in conjunction with the brake of the tractor. When time required for a pressure of the working fluid to decrease to a predetermined pressure is a predetermined time or longer, the control unit determines that the trailer is coupled with the tractor. When the time is less than the predetermined time, the control unit determines that the trailer is not coupled with the tractor.

An electropneumatic device for a pneumatic braking system, including a compressed air reservoir for providing a reservoir pressure; a brake pressure modulator which receives reservoir pressure and outputs a brake pressure at a brake pressure connection in a manner dependent on electronic braking request signals; a protective valve unit with a protective valve inlet, a first protective outlet and a second protective outlet; the protective valve inlet receiving the brake pressure which it can provide at the first and second protective outlets; a first and a second pressure line; and, a brake actuator that is connected to the pressure lines. The protective valve unit is configured to throttle the brake pressure output at the first protective outlet in the event of leakage of the first pressure line and to throttle the brake pressure output at the second protective outlet in the event of leakage of the second pressure line.

A pneumatic brake arrangement for a combination vehicle comprises park brakes, an air production module, and a first pneumatic control line pneumatically controlling the park brakes of the trailer from the tractor. This control line is divided into an upstream portion mounted on the tractor and a downstream portion mounted on the trailer. The first and second portions respectively include a first coupling head and a second coupling head. The arrangement can actuate all park brakes at the same time, based on a braking order received from the tractor cabin. The first coupling head is a vented coupling head, which allows air present in the upstream pneumatic control line portion to be exhausted when the first and second coupling heads are not connected.