Pallet-handling prowess: Automation & Robotics

A new automated system for moving and storing pallets is designed to boost the productivity and unmanned operating time of multiple connected machines.

Recently unveiled by Grob Systems Inc. in Bluffton, Ohio, the PSS-L linear pallet storage system is suitable for a variety of metal parts. The modular system can be used with individual Grob Systems machine tools and can interlink up to five of the company’s machines. The machines are connected to pallet storage racking with a maximum of 87 pallet positions. Pallets are staged close to the machines to shorten exchange times.

The PSS-L features a pallet-changing vehicle with a gripper that transports materials among work-setting stations, workpiece deposits and machines. Traveling on a linear rail, the vehicle can move in the x and y directions and is capable of rotary motion. The vehicle can move a pallet from a setup station to any of the machining centers in the line or store the pallet in the rack system. Pallets of parts machined by one of the machine tools in the line can be moved to the rack system or brought back to a setup station, where an operator can unload finished parts or reload parts into another fixture for an additional machining operation.

The new linear pallet storage system can link multiple machine tools. Image courtesy of Grob Systems

The PSS-L comes with production control software that allows autonomous part and pallet control, as well as monitoring and verification of tool resources for scheduled orders.

Construction of the PSS-L is “very rigid and heavy-duty,” said Derek Schroeder, sales supervisor for universal machines. The system is surrounded by a sheet metal enclosure with windows that provide visibility into the workspace and pallet storage locations. The PSS-L also includes a full base, which sets it apart from many similar systems “built on top of the concrete” in factories, he said.

Another key difference between the PSS-L and other linear pallet systems is in how signals and information are transmitted. He said similar systems normally employ a cable track for this purpose, but the cable track presents a problem when users want to expand the systems.

“Typically, customers start with one or two machines and keep adding machines over the years,” Schroeder said. “But if you do an expansion, the cable track is very hard, time-consuming and expensive to replace.”

So the PSS-L design leaves out the cable track and instead uses infrared signals for transmission purposes. He said this change makes expansions much easier and less expensive for users.