Service brake system of adjustable lever ratio

The utility model provides a service brake system of adjustable lever ratio, it is limited to solve in traditional tricycle the brake disc degree of adjusting, and adjusts the problem of difficulty, include with tricycle rear wheel complex brake disc, the pull rod transmission is connected to the disc cam, the base circle end of disc cam down and be equipped with the through -hole, the through -hole endotheca has a hollow sleeve, and the contact department annular welding of hollow sleeve and disc cam connects fixedly, fixedly connected with service brake footboard on the telescopic periphery wall, service brake footboard slope kickup, the flexion of service brake footboard is equipped with the locating pin, and eccentric end of disc cam is equipped with the connecting hole that corresponds with the pull rod tip, the connecting hole is at least two, is connected with reset spring between the eccentric end of disc cam and the automobile body, reset spring lies in not homonymy of disc cam with the service brake