Uses in Production Work. A magnetic chuck is essentially an electromagnet provided with a flat work face. Fig. 397 shows a magnetic chuck of the type commonly used on planers, milling machines, boring mills, and other machines producing plane surfaces. Fig. 398 shows how the magnetic chuck is adapted to a rotating spindle. Each of these tools are of the greatest service in machining small and rather thin pieces, as magnetic holding leaves the work surface clear for tooling.

The magnetic chuck shown in Fig. 397 is really two standard style 10-inchX32-inch Heald magnetic chucks, butted together end to end, used on a surface grinding machine. In the illustration

Fig. 397. Heald Magnetic Chucks Holding 528 Cones in Place for Grinding. With Ordinary Methods of Holding Work, Time.

Required 5 Hours; with Magnetic Chucks, Job Done in 1 3/4 Hours Courtesy of Heald Machine Company, Worcester, Massachusetts 528 cones are in position. Time for placing does not exceed twelve minutes. The cones are end ground to a limit of 0.002 inch.

The total time for the job from start to finish is 1 3/4 hours. Such a job illustrates the usefulness of the magnetic chuck upon a surface grinding machine. The results are similar when used upon the milling machine and for certain planer work.

Fig. 398. Heald Internal Grinder Fitted with Magnetic Chuck Courtesy of Heald Machine Company, Worcester, Massachusetts.

Fig. 398 shows the possibilities of a rotary magnetic chuck used in the grinding of holes, while Fig. 399 is illustrative of its use in lathe work. The essential quality of magnetic chucks is that the holding power is exerted upon the work without material straps, bolts, or other devices, which of themselves take up space and may interfere with the tooling which needs to be accomplished. Also they are instantaneously discharged by pulling a simple switch.

Fig. 399. Close View of Heald Chuck Holding Disc for Turning Operation.

Fig. 400. View of Magnetic Chuck Casting and Unit Coils.

Courtesy of Heald Machine Company,

Worcester, Massachusetts

The diagram, Fig. 400, illustrates the simple construction of the magnetic chuck.

Fig. 401. Heald Magnetic Chuck Faceplate.