Anti-skid vehicle brake system with fluid pressure actuated regulating valve

Anti-skid brake system comprising master cylinder means for providing upon actuation a supply of hydraulic brake pressure, wheel brake actuating means, brake pressure supply passage means between said master cylinder means and said wheel brake actuating means, fluid return passage means between said master cylinder means and said wheel brake actuating means for return of hydraulic fluid, control valve means for opening when actuated said wheel brake actuating means to said fluid return passage means, skid control means for actuating said control valve means upon detection of skidding so that the wheel brake actuating means is opened to the fluid return passage means, fluid return pump means provided in said fluid return passage means for return of said hydraulic fluid through said passage means, first check valve means provided between the return pump means and the wheel brake actuating means to allow fluid flow only toward the pump means, second check valve means provided between the return pump means and the master cylinder means to allow fluid flow only toward the master cylinder means, fluid pressure actuated regulating valve means for introducing upon actuation a restriction to the brake pressure supply passage means, valve actuating fluid passage means provided between the fluid return pump means and the regulating valve means, third check valve means which is disposed between said fluid return pump means and the second check valve means and allows fluid flow only toward the second check valve means, said valve actuating fluid passage means being connected with said fluid return passage means at an area between said second and third check valve means.