Braking pressure control apparatus capable of switching between two brake operating states using power-operated and manually operated pressure sources, respectively

Abstract

A braking pressure control apparatus including a first pressure source including a power-operated pressurizing device, a second pressure source operable by a manually operable brake operating member to pressurize a fluid to a pressure higher than a level corresponding to the operating force of the brake operating member, a switching device for selectively placing the braking system in a first state in which a brake cylinder is operated with the fluid pressurized by the first pressure source and a second state in which the brake cylinder is operated with the fluid pressurized by the second pressure source, and a change restricting device operable upon a switching between the first and second states, to restrict a change of the operating state of the brake operating member and a change of the brake cylinder pressure, which change take place due to the switching, or a switching control device for controlling the switching device on the basis of the running condition of a vehicle whose wheel is braked by the braking pressure.