Precision chucks cor aircraft industry

Modern Machine Shop, March, 2002 by Shavna R. Pope

Northfield precision instrument, booth 2345

Precision workholding air chucks designed to meet a range of needs in the aircraft industry will be showcased.

One such chuck, Model 425, has been developed to hold skin-to-airframe fasteners during hard turning and tapping operations. The chuck features special flow control, sub-jaws and inserts.

For the flat-head style fasteners, the chuck jaws open wide enough to clear the head of the fastener. The part is pushed into the chuck to the stop. The jaws close and the part is ready. A special stop allows a continuous chip to exit from the side.

The button head style fastener goes all the way into the chuck. The jaws begin to close in sequence with a pusher piston mounted on the face of the chuck, forcing the part up against the back of the jaws. The pusher is adjusted with a built-inflow control valve. This method allows for greater accuracy than had been possible before, the company says.

To accommodate the variety of sizes, the chuck uses a sub- jaw/insert setup that allows users to change sizes by simply removing three screws and three inserts.