THE WONDERS OF LIFTING MAGNETS.

King Country Chronicle, Volume V, Issue 392, 2 September 1911, Page 3

THE WONDERS OF LIFTING MAGNETS.

+ ; WHAT A BOY'S TOY HAb | ! BECOME. I Although the lifting magnet <«is by : no means new, during the last two ; or three years in particular its uses have multiplied to such an extent that many new and widely different ; types have been designed to handle the multitudinous shapes of metal ; produeed. The magnet, is last becoming adopted to handle all forms of iron and stee! from iron dust or i scraps to weights of 20,000 pounds. . In fact, the world's largest magnet will lift as much as 0,000 pounds. j Thus, Mr. W. Frank M'Clure point,? out in a paper the toy magnet o! i our boyhood is converted into a use- , ful instrument in the workshop. i Used at first chiefly in carrying j iron and steel to and from cars 01 | storage piles, the lifting magnet is j now utilised in breaking 1151 impel - ; feet castings, in holding sheets cil metal in position while being revited in the construction of ships, in lifting a "sow and pig? l " nt the furnae.es, also as a gigantic broom to sweep ■ both the large and small pieces oJ : iron, and in many other ways. A : half-dozen kegs of nails may be seen travelling throng!) the air. held b\ ! magnetic lines of foreo despite tlu j wooden coverings of the kegs. Even j two or three men are sometime:- j lifted from the ground, their feet . resting upon a metal sheet, which it j firmly held by the magnet.

Lifting magnets are usually opera<- : ed from an electric, overhead tra\e!l- j ing crane, but they may also be, j operated from a locomotive erane. | Within the rruagnet are coils witi: j which the servk'e wires are connoc.;'-

just as an incandescent lamp is c. ii nected bv service wires. The winding . is, of course, insulated. When thi • magnets handle hot material. tl.<\ are wound with fireproof wire. )ht movements of the magnet are directed by the operator of the crane, i The opening or closing of a svvif.'h ; turning the electricity on or off, ; causes the magnet, to pick up or re- j lease its load.

The 20,000-pound weight referred <<: l as a typical large list mane by mag- ■ net power is in the form of a "skulcracker ball." used to break up im- j perfect metal that is to be remelted. The magnet used for this lift is 5: .nches in diameter, -and its weight 1.800 pounds. It requires i feet 0 : inches head-room. When this great j weight has been lifted high in tlu | air, and the current, is turned o!T { and the "skull cracker ball" has fa 1. j len, the magnet. again picks it uj | easily and quieklj without any assistance from any one on the ground

As a rule, a man on the -round if not necessary where a lilting magnet : is employed, for the reason that, there are no chains, slings, or hoist j ing blocks to be iitted about tlu j weight to be lifted. However, there! are a few instances where a ground man facilitates the work of the mag- ! act. One of these is the lifting oi ; an ingot, say. of 6,000 pounds. If a : ground man places the magnet, two! d£ tlie.se ingots can be lifted ; other- j wise only one at a time. For if two | ingots are to be lifted simultaneous- j ly, they must, be in proper position, | on account of their weight , for the j magnet to grip them in their right | place. j

Instead of the round magnet just described. a rectangular magnet, is ised in lifting a "sow and pigs" at

the furnaces. When thus lifted from the sand thev are not white lint, but yet, strongly heated. Hot metal in the. form of billets is also lifted by a special magnet to a conveyer, and taken to where it: is sheared or :ut into shorter lengths or to where it may be stamped out by a hydraulic press into car wheels and finished upon a lathe. A rectangular type :>f magnet is also used for holding steel plates in place to !>e nvetei in the construction of ships. For two or three years past a number o! these magnets have been in use at the imperial shipyards in Yokohama. •Japan. Another interesting sight is afforded in the lifting of a very long metal sheet by one magnet applied at the sheet's centre. The ends oi the sheet may dip down to an angle of <•> ueg. ami still the sheet lie held tightly by the magnet. The use of the lifting magnet makes it possible to pile scrap iron in storage piles of unusual height with. ease. It is not uncommon to see storage piles of this kind 25 feet" high, and the work of piling it. is dime with great rapidity. In loading from waggons to storage piles, the work of hours when done by hand is reduced to a few minutes by the use- of the magnet. With the f,2-inch magnet, :'-00 to 800 tons of. scrap are easily handler in a day of twenty-four hours at an openhearth furnace, even when four hours are a H«wetl for delays. When thus operated day and night, the magnet takes the place of fourteen labourers. If operated with a specially fast crane, the amount handled is still further increased.

The magnet mentioned as the most powerful in the world is (>0 inches in diameter and will handle "skull cracker balls" weighing 30,000 tc 50,000 pounds. —■ " Popular Science Sittings."