A tool-handling device developed for more efficient automated production of cutting tools may also be helpful for machine shops that have their own in-house area for tool regrinding or making custom tools. An adjustable tool pallet from Active Automation (Elk Grove Village, Illinois) holds tools of various diameters. The pallet reduces the various costs associated with storing and retrieving dedicated pallets for different sized holes.

To understand how the adjustable pallet works, it helps to understand why it was developed. Increasingly, the tool and cutter grinders used to manufacture rotary tools such as drills, end mills and reamers are served by free-standing robots or integral pick-and-place attachments that automatically load tool blanks into the grinder and unload the finish-ground tools. Usually, the blanks and the ground cutting tools are held in pallets that have a grid of holes drilled to the size (diameter) of the tool being produced. Depending on the                           space availability,separate pallets may be used to hold the blanks and finished cutting                           tools, or the samepallet may be used to hold both.

The adjustable tool pallet adjusts to hold a different tool diameter in minutes.

When production switches to a different tool diameter, the pallet must be changed for one with appropriately sized holes. Because of the many standard English and metric tool sizes, the cutting tool manufacturer quickly accumulates a large number of pallets, which must be stored in such a way that they can be quickly located and accessed. The setup person must return the pallet used for the job just completed to the pallet storage area, locate the pallet with the hole size required for the next job, and install it at the machine. If the manufacturer receives an order for a tool size and does not have the appropriate pallet, the manufacturer must buy or make a pallet drilled to the correct hole size, which can delay the start of the job.

Active Automation's adjustable tool pallet is topped by three plates, each with square or octagonal holes, that move relative to each other to provide an opening with an inscribed circle size that approximates the diameter of the tool being processed.

The adjustable tool pallet simplifies handling of various sizes of cutting tools by adjusting to the diameter of the current tool. The top of the pallet consists of a stack of three plates, each with a grid of square or octagonal holes. A thumbwheel adjusts the relative position of the plates: The top and bottom plates move in one direction while the middle plate moves in the opposite direction, reducing the resulting opening to the size of the round or multi-sided tool being processed.

The robot arm on a Rollomatic tool and cutter grinder loads tool blanks from the adjustable tool pallet at rear and delivers ground tools to the adjustable pallet in the foreground.

The relative movement of the plates is such that the centerline of the opening for the tool remains constant. As a result, the programmed movement of the robot or pick-and-place device does not have to be adjusted to compensate for a different tool diameter. The standard adjustable pallet accepts tool diameters from 0.025 inch to 0.500 inch; specials can be ordered capable of handling tool diameters to 1.25 inches. Because space for the pallet on the tool and cutter grinder varies from manufacturer to manufacturer, many pallet models are available to fit AAI, ANCA, Rollomatic, Unison, Walter and other tool and cutter grinders. Active Automation recommends that the pallets be purchased in pairs to avoid downtime caused by idling the machine when inserting                                         blanks in and unloading finished tools from anonly                                         pallet.

Sam Marinkovich, president of Active Automation, notes that for cutting tool manufacturers, the adjustable tool pallet represents a significant cost savings: It replaces 13 or more conventional pallets, each of which can cost $350 to $800 depending on the manufacturer. Ability to use the same pallet for different tool sizes helps to minimize downtime for setups and saves time that would otherwise be lost moving pallets in and out of storage. Just as importantly, the automated loading and unloading of cutting tools from the adjustable pallets through the
various production steps reduces handling by operators, resulting in fewer injuries
and less in-process damage to expensive tools. Similarly, the adjustable pallet will
benefit machine shops and other shops involved in tool grinding.

Tool Palletization

Whether a toolmaker is placing prepared or raw blanks into a tool and cutter grinder, or removing finished products from the grinder,
Active Automation Inc., Elk Grove Village, Ill., has developed a product to help them. Its adjustable tool pallets accept shank diameters from 0.025" to 0.5". Specials can be ordered that accept diameters up to 1.25". In addition, the pallets also accept square shanks and other shapes with an even number of sides.

According to Sam Marinkovich, Active's president, this eliminates the need to have separate pallet for each tool diameter. "A toolmaker might need 150 or more pallets to accommodate all its tool sizes, and the adjustable                                                     tray eliminates that need," he said.

The pallet's top and bottom plates move together in unison as the thumb wheel is adjusted, while the middle plate moves an equidistant in the opposite direction. This plate movement provides a constant tool centerline, so that once a robot is "taught" the centerline, it's able to grip each tool-without recalibration-regardless of the tool's diameter. Of course, even without a robot, Marinkovich said the pallet is an effective tool-handling system.

Each pallet should be adjusted so there's a slight amount of clearance between the tool and the pallet opening. This allows a tool to be easily inserted and removed, said Frank Kowalski, engineering manager for Active Automation. He added that as the robotic gripper experiences wear and loses accuracy, a chamfer on the bottom of the tool or top of the opening helps guide the tool into the tray.

Because tool and cutter grinders from individual machine builders have different footprints, Kowalski said Active either has to design a pallet based on a manufacturer-supplied print or reverse-engineer it when a print can't be obtained. Pallets are available for most of the popular machines on the market, including ANCA, Walter, Rollomatic, Unison, AAI and other tool grinders.

"Cutting Tool Engineering", January 2002 (page 53-54