A belt conveyor system with a distributing belt conveyor unit having upper and lower movable frame assemblies that are pivotally connected to a gear unit that simultaneously moves the lower movable frame assembly in opposition to the movement of the upper movable frame assembly, therein allowing the belt to track smoothly when transferring the articles between one branch belt conveyor unit and two or more branch belt conveyors units. The construction of the distributing belt conveyor unit allows for easy removal of the belt.