Automating a Product Conveyor

A large baking company supplied a broad range of bakery products to retail customers located over a large area in the Rocky Mountain region. Distribution of all products to the retailers was made via the use of eighteen-wheel tractor-trailer units. Trailers were loaded by use of fork trucks that picked up their loads from product palletizers and placed the pallets in the proper trailers, which were parked according to destination. Given the size of the bakery and the number of fork trucks, traffic in the shipping area was usually congested. To reduce the cost of the loading operation by reducing the number of forks and drivers, and to speed up the operation, the owners decided to automate the process.

A single conveyor would pick up the loads from the palletizers and convey them to transfer units which would place the pallets on take-away rollers that would automatically load them into the correct trailers. These would be new trailers with powered rollers on their floors. That is, the entire loading operation would be fully automated following the palletizing step.

The configuration of the main conveyor had to allow for the location of the transfer units, and the location of the transfer units was determined by the spacing of the dock bays into which the trailers had to be parked. The speed of the main conveyor had to be slow enough to accommodate the transfer operations. Spacing of pallets on the main conveyor was therefore a critical parameter.

After the conveyor manufacturer had made preliminary layouts to show how the individual trailers could be loaded, a project manager was called in to supervise the remainder of the project. His responsibilities were primarily to assure that the budget and schedule were met. However, upon noting the rate at which products were being palletized and at which pallets would enter the new conveyor, he asked if the spacing between pallets on the conveyor would accommodate the transfer operation. It would not. That is, to convey the number of pallets to be conveyed per unit of time, the transfer units would be unable to remove the pallet loads form the main conveyor, and if the main conveyor were to be slowed down, it would be unable to keep up wti the bakery production rate.