DPU torque pipe shaft rotation is coupled to push the pointer across the scale panel by connecting link within the switch case. An actuating cam, directly connected to the heart of the torque tube, rotates with the motion of the shaft. By pressing and locking the buttons as they move on and off the cam, two rotor feeder roller / actuator frame units, one for each button, respond to torque tube spin. With elevated and low panel switch changes, the DP rates at which the buttons are actuated can be adapted on the scale panel.
Switch contact life is influenced by various application conditions such as temperature, humidity, airborne contamination, vibration, amount of plunger transport, cycling velocity and frequency of plunger transport (and others), as well as electrical (device) characteristics.