Tring Corp., Orrville, OH, has partnered with furnace builder Seco/Warwick Corp., Meadville, PA, to design an automated system for hot forming hole-saw blades. The equipment combines a custom rotary hearth furnace with a precision hearth.

In the saw-blade forming system, an operator loads straight blades into a magazine. The loading robot loads single blades into slots in the furnace hearth where they are heated to the appropriate temperature for heattreating and forming. The robotic unloader reaches into the furnace with a special gripper, grasps blades one at a time and places them in water-cooled dies, where they are formed into various hole-saw sizes. The furnace can handle blades with diameters from 0.75 to 6 in. To provide precise indexing, the furnace features an indexer rather than a complex servo drive.

A single PLC monitors the entire operation. The Allen-Bradley Panel-View operator interface checks system status and controls loader/unloader operation, furnace temperature, hearth indexing, atmosphere, die cooling and the former. A diagnostic system pinpoints the location of any problems and suggests corrective actions. Allen-Bradley remote I/Os and Numatics valves speed installation and field wiring. Tring also offers sawmakers a dual-loading configuration that doubles the production of a single furnace. Blades of more than one size can be run simultaneously by incorporating two loaders and unloaders in one furnace. The equipment can be supplied as a single system, with a second system retrofitted.

Each line can produce more than 1900 hole-saw blades per eight-hour shift. A single system requires 400 sq. ft. of floor space while a double system requires only 600 sq. ft. Atmosphere is controlled in the furnace and in the forming station, providing heat treating and scale-free parts. No blasting is needed.

In addition, quick-change tooling allows forming of hole saws of various diameters in a single operation. Size changeover time is less than 15 min. and, on double systems, one line can be changed while the other line continues producing blades.