Load sensing control mechanism for vehicle hydraulic brake system

Claim 1

In a hydraulic pressure control mechanism inserted in a hydraulic conduit extending between a hydraulic master cylinder and wheel brake cylinders of a powered vehicle for control of the pressure prevailing in the latter cylinders, said mechanism being resiliently bridged between a chassis frame and a wheel axle of said vehicle through the intermediary of a load-sensing spring and a transmission rod means and comprising a cylinder, a control piston slidable therein, valve means provided in the lastmentioned cylinder for on-off control of the passage of the hydraulic fluid flow from the master cylinder to the wheel cylinders, said piston having two different hydraulic pressure receiving areas for cooperating with said valve means, the improvements comprising a ball portion having a spherical acting surface integrally formed on the iNner end of said rod means and a coating surface formed on an extension of said control piston, said both surfaces being kept always in pressure contact with each other; an abutting ring; a biasing spring provided in said cylinder for the control piston, said spring acting on said ball through the intermediary of the abutting ring consisting of a cylindrical part kept in slidable contact with said cylinder and having a ring part having a curved sectional configuration.