What is a Power and Free Conveyor?
A Power and Free conveyor can be thought of as a train track system, with multiple trains moving independently, starting and stopping, changing tracks as required to get them where they need to go. We refer to this as a non-synchronous conveyor.
Power and free conveyors get their name from the basic design; the engine is a continuously moving “power” chain running in the upper track, and the loads are suspended from “free” trolleys located in the lower track. The “free” trolley has a cast body and 4 load carrying wheels. It has a front flipper, and a rear flipper. The cast pusher dog mentioned earlier rides between these two flippers, and controls the movement of the trolley forward but also restrains it if it is going down a decline. The powered chain has a cast iron “drive dog” attached that will engage with the flippers of the free trolley, thus propelling it forward.
The most common style of power and free conveyor is where the load is being carried beneath the track, (we call it “slot down”).
This particular conveyor can also carry the load above the track, making it ideal for the highest quality paint systems where zero defects can be tolerated. Anything originating from the conveyor, be it oil or dirt, is eliminated. This feature also allows it to be used for over/ under systems, which reduce the amount of space used.
In conclusion, the power and free conveyor can be a large investment compared to a simple overhead conveyor and so it is best applied to more expensive products being carried through complex processes that extend over multiple shifts. These factors will all contribute to a suitable ROI.