An exploded version of a Grayhill rotary switch deck section is shown here. A typical deck section consists of a common pole and it’s integral terminal, switch position terminals and a moving contact mounted to the shaft. In an actual switch, the moving contact touches, or contacts, the selected switch position terminal and the common pole. As the shaft is rotated, the moving contact is moved between the switch position terminals. Note that contact is always maintained between the moving contact and the common pole.