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: 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 is located in a reaction chamber which is connected to a second control pressure connection.

Abstract: The invention relates to a load-controlled brake force controller system for a pneumatically operated brake for tractor and/or trailer vehicles. A housing includes a load-controlled brake pressure controller for regulating the control pressure released by a brake valve as a function of the load sustained by the vehicle. A relay valve connected in series relationship with the brake pressure controller to cause compressed air to be introduced to the brake from a reservoir when the brake valve is activated. The relay valve being activated by a relay piston which is pressurized toward an open direction of the relay valve by a modulated pressure and toward a closed direction of the relay valve by the braking pressure in an outlet chamber which is connected to the brakes and which can be connected by the relay valve to the reservoir.

Abstract: A relay valve device which is actuated by the presence of a control signal pressure to a higher pressure supply into a consumer circuit than when the control signal pressure is not present. The relay valve device includes a first control surface and a second control surface, and includes a shut-off device disposed in the feed line of the control pressure to the second control surface. The shut-off device is opened when the control signal pressure is present and is closed when the control signal pressure is not present, and also causes the second control surface to be connected with atmosphere.

Abstract: The invention relates to a load-dependent brake pressure system for a pneumatically activated motor vehicle and/or motor vehicle trailer brake apparatus with an entrance device having an initial entrance phase in which the full control pressure is delivered to the cylinders of the wheel brakes. In an emergency situation, the supply pressure which is available on the vehicle must be able to be conveyed in a graduated and controlled manner as the brake pressure is applied to the wheel brakes. The present load-dependent brake pressure system which, in an emergency situation, makes possible the application of brake pressures which are higher than that corresponding to the control ratio up to the available delivery pressure, includes an entrance valve and piston, a control valve, a brake control piston, a relay valve, auxiliary valves, a control, delivery, brake pressure connections and chambers, and a valve tappet for controlling brake pressures in multiple phases.

Abstract: Apparatus for adjusting a mechanically operable load-dependent braking force regulator including a control shaft having a cam surface for setting the axial position of a push rod which controls a valve for supplying brake-operating pressure according to the axial position of said push rod. The axial position of the push rod is set by the cam surface on the control shaft which is rotated through a lever reflecting the actual vehicle load. The regulator may be set at a location away from the vehicle, such as a test rack, then installed on the vehicle. Thus it is not necessary to transport the testing equipment to the vehicle.

Abstract: A vehicle load controlled fluid brake pressure regulator having a relay valve portion that includes a variable area differential relay valve piston, the effective area of which varies in accordance with different load conditions. A control portion of the brake pressure regulator includes a stepped control piston having two piston faces subject to the load dependent pressure of separate air springs of the vehicle, so as to be axially displaceable for different load conditions. Oppositely inclined control surfaces of two cam members carried by the control piston translate the axial position of the control piston to the relay valve piston via an actuator stem. One cam member is axially adjustable relative to the other, so as to cause the hollow or low point of the cam profile formed by the inclined control surfaces to engage the actuator stem for any desired "empty" load setting of the relay valve portion.

Abstract: An adapter for use in a fluid pressure operable brake system, including a vehicle load responsive brake force regulator, for testing the brake force regulator for pressure leakage. The adapter is so designed as to require a single connection to be made to a source of test pressure rather than the two connections presently if the test pressure source is connected directly to the brake force regulator.

Abstract: In a variable load valve device of the type employing a walking beam type lever arrangement via which the control and compensating pistons are interconnected to obtain proportional control of the brake pressure, there is provided an externally accessible screw adjustment for varying the tension of a bias spring acting on one of the levers, whereby the proportional brake control is withheld until a predetermined level of brake pressure is achieved corresponding to the spring bias.

Abstract: In a variable load valve device of the type employing a walking beam type lever arrangement via which the control and compensating pistons are interconnected to obtain load-dependent control of the brake pressure, there is provided a screw adjustment that acts through an auxiliary piston to vary the tension of a bias spring acting on one of the levers of the lever arrangement to bias the compensating piston in order to withhold the load-dependent brake control until a predetermined level of brake pressure is developed. The auxiliary piston is subject to brake control pressure supplied to the variable load valve inlet and in one embodiment of the invention, the auxiliary piston is formed to urge the piston in a direction to counteract the spring force and in another embodiment, to urge the piston in a direction to supplement the spring force.

Abstract: A variable load valve device having a piston subject to air spring pressure that varies with vehicle loading to position a cam member formed on a control piston in accordance with the vehicle load condition. The cam member acts through a plunger or push rod to operate a relay valve device via which brake pressure is controlled. A spring that acts on the control piston in opposition to air spring pressure has an adjustable deflection characteristic wherein a clamping device threaded within the spring coils is rotated by a screwdriver or the like. An adjustable screw that serves as a stop for the spring clamp member is provided with a through bore to accommodate passage of the screwdriver into engagement with a slot in the clamp member to facilitate rotation of the clamp, without requiring valve disassembly or component replacement.