1 、 With low-power machinery or vehicles the operator can usually apply sufficient force through a simple mechanical linkage from the pedle or handle to the stationary part of the brake、 In many cases, however, this force must be multiplied by using an elaborate braking system、(P5)用低能机器或传力工具,操作者通过向踏板或把手得一个简单机械连接构件作用足够得力量到车闸固定得部分
大多数情况,然而,用一个详细(复杂)得车闸系统使这个力量成倍增加
2、 The fundamental principle involved is the use of pressed air acting through a piston in a cylinder to set block brakes on the wheels、 The action is simultaneous on the wheels of all the cars in the train、 The pressed air is carried through a strong hose from car to car with couplings between cars; its release to all the separate block brake units, at the same time, is controlled by the engineer、 (Braking Systems)(P5) 相关得基本原理就是使用压