Keeping bar stock unmarked, holding a small diameter on center, holding a thin-wall part, ejecting parts and working with extruded bar shapes are common gripping dilemmas for the Swiss-turning industry. Hardinge offers a number of gripping devices for machining small diameter parts for medical component manufacturing. One category of products includes Swiss-type headstock collets, pickoff collets, carbide guide bushings, bar loader collets and custom manufactured devices for Swiss turning.
The Swiss-type collets are finish ground for a smooth, concentric gripping area (order hole) for the bar stock or work piece and are inspected on a Hardinge SUPER-PRECISION® (0.000015 in. TIR) headstock to meet strict concentricity standards. These headstock collets, pickoff collets and guide bushings are available in many styles and sizes. Their standard round guide bushings are carbide-lined to keep the stock clean and unmarked. Hardened steel or Meehanite-lined bushings can be made for certain stock that is not compatible with carbide. Standard extended-nose headstock and emergency collets feature added length (straight or tapered) for doing pickoff work or to compensate for tooling interference. Emergency collets can be machined to the desired bore size to accommodate small runs or get you by in a pinch while they ship your desired size collet.
Grippers are available with special accuracy order holes of 0.0005 in. or better for holding strict tolerances, as well as micro-inch finish order holes. Collets and guide bushings for D-shaped and other extruded shapes, along with pickoff collets with a built-in spring ejector that pushes the part into a basket or conveyor to automate the process are also available.
Filed Under: Design World articles, Medical, Bushings • plain (sleeve) bearings