A BRAKE CONTROL VALVE DEVICE FOR USE IN A VEHICLE WITH A BRAKE CYLINDER

摘要

This invention relates to a vehicle brake apparatus wherein a service brake application is effected by a spring in response to the reduction of the pressure of fluid in a first chamber on one side of a brake-applying piston, and an emergency brake application is effected by the establishment of a fluid pressure in a second chamber on the other side of this piston whereby this other side of the piston is subject simultaneously to both the fluid pressure force thus established and the force of the above-mentioned spring. A brake control valve device that includes a pair of self-lapping valve devices which respectively control the degree of reduction of the pressure of the fluid in the first chamber and the degree of pressure of fluid established in the second chamber, also comprises a spring-biased lever having a fulcrum adjustable according to the load on the vehicle and an operator-controlled device for rendering the spring-biased lever operable to so effect operation of the pair of self-lapping valve devices as to selectively effect a service or an emergency brake application and a subsequent brake release.