GM4000A™ Switch Machine - Alstom

General Description1.7.1. Cam BarThe split link cam bar is located under the main drive module and point detectionmodules. Figure 1-5 shows top and side views of the cam bar. The cam bar is visible inthe assembly drawing, Figure 7-1 sheet 2.TOP VIEWSIDE VIEWFigure 1-5. Cam BarThe cam bar moves in a machined channel within the switch machine base and is keyto the operation of the point detector system. It is the mechanism that, in conjunctionwith the lock rod, locks the switch points in position. The cam bar also preventsindication while the switch machine is unlocked.When the lock rod is out of position relative to the cam bar locking dog, a fouledcondition occurs. The split link allows the cam bar to separate so the throw bar cancomplete stroke without locking the lock rod or indicating position (normal or reverse).This occurrence allows switch points to be moved by the hand throw device. With thelock rod out of position, the split-link feature permits the hand throw lever to bepositioned in the latch stand.When the lock rod is in adjustment, the cam bar automatically resets itself whenoperated once manually or electrically.P2496, Rev. 6, Jul/11 1-12 Alstom Signaling Inc.