Major elements of the new system include numerous belt and roller conveyors, storage racks, transfer carts, track-type shuttles, a glass separating station, a turnover device, and two Fanuc S420 robots (supplied by Ford). Control is via an Allen-Bradley PLC. The system accommodates six different styles of windshields. Changeover between styles is accomplished with the push of a button.

Peak's equipment features design simplicity and easy accessibility, while providing hands-off handling. The system includes 50 racks. Each rack holds 30 windshields, for a capacity of 1500 parts.

"This system has greatly improved our product flow over the old manual setup," said Ford project manager Dave Mersino. "Windshields are now delivered to the washer load station on a just-in-time basis.

"With the previous system, the windshields were manually loaded and off-loaded on trucks for transport through this portion of the line, requiring a large truck storage area and a high in-process inventory.

"Our quality has also improved with this setup," Mersino added. "Quality problems with the windshields coming out of the bending oven were often not detected for several days if those parts were waiting in storage while another style was being run. With this system, any quality issue is caught within several hours, at most."

The system begins at the bending ovens, where windshields exit as bent parts; that is, two pieces of inner and outer glass ready to be cleaned in preparation for the addition of a sheet of vinyl in between. The first Fanuc robot is located at the bending oven exit. Using a suction cup end-effector, it loads each bent pair into a storage rack mounted on a roller conveyor.

The full storage rack holding 30 bent parts is routed to a storage area consisting of nine accumulating conveyors. These conveyors are serviced by two shuttles, one on the in-feed end of the conveyors and one on the out-feed end. A self-powered cart, riding on tracks, transfers loaded racks to the accumulating conveyors. Each rack is placed on one of six conveyors as dictated by the logic system. The other three conveyors in the center of this layout are used to store empty racks ready for transfer back to the bending oven exit point.

The out-feed shuttle system transfers loaded racks out to the six accumulating conveyors to a roller conveyor for transport to a robot unload station. This second Fanuc robot places each bent pair onto a belt conveyor leading to the washer.

Peak also provided the equipment used at two stations just ahead of the washer. The first is a pneumatically actuated device that uses suction cups to separate the two glass pieces and place them individually on the conveyor belt. The second is a motor-driven, eight-part turnover unit that uses a precision clutch brake to index and roll the glass through 180°. The turnover puts the glass in a "wings down" orientation to facilitate handling further down the line.

The Peak-built storage racks in this system have a steel framework with steel arms. Silicone tubing on the arms cushions the glass and provides heat resistance. Tight dimensional tolerance rack-to-rack is important. The robots are programmed to go to a specific point in space, and the rack-held glass must also be delivered precisely to that point for pickup.

The logic system for shuttle cart movement and control involves sensors on each cart and the nine storage conveyors. The location of each of the 50 carts used in the system is know at all times.

"We're extremely pleased with the efficiency of this system," said Mersino. "Since its startup, it has reduced inventory and glass breakage, improved product flow, and helped to minimize the impact of any quality issue."

Peak Industries has been a supplier of custom automation, assembly tooling, special assembly machines and systems for the automotive and other manufacturing industries since 1966.