In today's lean manufacturing environment, every piece of equipment can have a significant impact on the efficiency of the production process. That became clear when the Tower automotive plant in Milwaukee, Wis., prepared to begin production of Dodge Ram truck chassis frames.

Tower needed containers that would be compatible with a new, automated production process. After the irregularly shaped frames pass through manufacturing, two materials handling robots would grip the frames and transfer them to crates. From there, the parts would move by forklift to the assembly area.

The challenge was to find a container that could give the robots unimpeded access, secure a 3,000-pound load of 77 parts without any banding or manual intervention, and still allow easy unloading at the assembly cell. Clearly, customized crates were the answer.

Tower and ABB, the robots' manufacturer, worked with the container supplier to design and test prototypes for more than a year. The result: an innovative design that uses their own weight and gravity to secure some parts, while the shape of the container and bracing hold the rest of the components.

The crate has an inner frame that actuates a clamping bar. During loading or unloading, a floor-mounted pedestal holds up the inner frame. When the container is removed from the pedestal, the inner frame tips downward, clamping the parts against the wall of the crate. When the load arrives at its destination and is set on another pedestal, the cam lock opens, readying parts for picking.

Parts can only be placed in the crate in the correct orientation for processing at the next station. The error-proof crates also are color-coded to ensure that the right parts are placed in the right crate.