Abstract: A load-responsive pressure reducing valve assembly for hydraulic brake systems to be interposed between a brake master cylinder and the rear wheel brake cylinders of a wheeled vehicle and includes a fluid pressure proportioning valve which restricts the flow of fluid from the master cylinder to the brake slave cylinder during a predetermined range of increasing fluid pressure supplied therefrom to the brake slave cylinder. The assembly also incorporates an inertia-responsive valve which includes a valve member usually in the form of a ball which is responsive to a predetermined rate of deceleration so as to vary fluid pressure acting on the aforesaid proportioning valve to thereby correspondingly vary or set the reduction starting pressure of the fluid pressure proportioning valve.

Abstract: A reducing valve which performs proper vehicle braking control in proportional response to the load being carried on the vehicle by sealing off a hydraulic braking pressure, which is regulated to be proportional to the load on the vehicle, in a control chamber through the use of a control valve for the control of the pressure reducing function of the reducing valve. The control valve is regulated to remain open, in opposition to the applied hydraulic pressure from the braking pressure source, in proportion to the increase of vehicle load thereby correspondingly raising the reduction starting pressure of the reducing valve which reduces the braking hydraulic pressure to the rear wheel brakes of the vehicle.

Abstract: A load responsive pressure modulating valve device for use in a brake system of a vehicle is so constructed that the starting pressure for the pressure modulating operation is controlled by a specific valve operated by a partial pressure of the input hydraulic brake pressure. The device is capable of distributing the hydraulic brake pressure corresponding to a transient weight transfer from rear wheels of the vehicle to front ones caused by the braking operation, to the front and rear brakes by varying the starting pressure in response to load and deceleration of the vehicle.