Models 5E, 5F, 5G & 5H Electric Switch Machines: Single ... - Alstom

Theory of Operation2. SECTION 2 - THEORY OF OPERATION2.1. GENERALThis section discusses the basic operation of the 5E, 5F, 5G, and 5H Switch Machinesand highlights the main differences between the four versions. Table 1–1 compares andsummarizes the principle features of each switch machine.2.2. POWER OPERATIONA switch machine is an electro-mechanical device consisting of a motor and gear trainwhich moves the rails (points) into position for a rail vehicle to change route.The motor uses a clutch and gear mechanism to move the throw bar. The throw rodconnected to the throw bar moves the switch points. Depending on the direction ofrotation of the switch machine motor, either the near or far switch points will close.The lock rod is connected to the switch points by the lock connecting rod. The lock rodmechanically locks the switch points against any movement away from the position ofcorrespondence, which is defined as the point where the position indicated by theswitch call circuitry “corresponds” with the indications provided by the point detectorcircuits. The switch machine remains in the locked position until the machine receives asignal to reverse the action.The point detector rod is connected to movable switch points by the point detectorconnecting rod. The point detector rod operates the detector as the switch points move,providing the associated circuits of the display panel and signal control relays with theswitch point position indications. Figure 2–1 shows the cam bar and point detector rodalong with the detector yoke. Figure 2–2 shows each of the four operating positions.The point detector motor control contacts remove energy from the motor after eachstroke.P1293, Rev. Jun/07 2–1 Alstom Signaling Inc.