Rollers attached to the end of a sensing arm assembly ride both sides of the belt edge, detecting even slight variations in the belt path. Employing the force of the wandering belt, the arms automatically position a steering idler in the opposite direction of the misalignment. Transferring the motion to the steering idler through a unique parallel linkage requires less force to initiate the correction, so fine-tuning of the path can be continuous, active and precise.
According to Dan Marshall, product engineer for Martin Engineering, “The biggest issue from a mistracking belt is spillage,” Marshall said. “If the belt is out of place, it’s not handling the load properly, and that will cause material to leave the belt. The buildup can be extremely rapid, especially from a high-speed conveyor, which drives up expenses due to wasted material and added cleanup. It also introduces the inherent risk, which is always present when people are working around a moving conveyor.”
The multipivot design of the Martin system corrects many of the problems exhibited by current trainer systems on the market such as belt switches, vertical guides, v-idlers, crowned pulleys and sensing-roll trainers. Some correction systems have a tendency to overcompensate, requiring a safety tether or lead line to catch the device when the force of the misalignment detaches the unit from the mainframe. Many of these systems correct mistracking after it has occurred, rather than constantly working to prevent it. By continuously mitigating tracking issues rather than reacting to them, the risk of failure is significantly reduced.