THE WONDERS OF LIFTING MAGNETS.

Ohinemuri Gazette, Volume XXVI, Issue 3451, 29 October 1915, Page 4

THE WONDERS OF LIFTING MAGNETS.

WHAT A BOY'S TOY HAS

BECOME.

Although the lifting magnet *s by no means new, during the last tyro or three years in particular its usei have multiplied to such an extent that many new and widely different types have been designed to handle the multitudinous shapes of metal produced. The magnet is fast becoming adopted to handle all forms of iron and steel from iron dust or scraps to weights of 20,000 pounds. In fact, the world's largest magnet will lift as much as 50,000 pounds. Thus, Mr. W. Frank M'Clure points out in a paper the toy magnet ol our boyhood ', is converted into a useful instrument in the workshop. Used at first chiefly in carrying iron and steel to and from cars or storage piles, the lifting magnet is now utilised in breaking up imperfect castings, in holding sheets d metal in position -while being revited in the construction of ships, in lifting a "sow and pig»" at the furnaces, also as a gigantU broom to sweep both the large and small pieces 01 iron,, and in many other ways. A half-dozen kegs of nails may be seen travelling through the air, held.by magnetic lines of force despite th» wooden coverings of the kegs. Ever two or three men are sometimes lifted; from the ground, their feet resting upon a metal sheet > which is firmly held by the magnet. Lifting magnets are usually operated from an electric overhead travelling, crane, but they may also be operated from a locomotive, crane. Within the magnet are coils with which the service wires are connected just as an incandescent lamp is connected by service wires. The winding is, of course^ insulated. When th« magnets handle hot material, they are wound fireproof wire. Tbt novements of the magnet are directed by the operator of, the crane. The opening or closing of a switch, turning the electricity on or ofl, causes the magnet to pick up or release its load. ' ■ ' t

The 20,000-pound^ weight referred tc as atypical large lift made by magnet power is in the form of a "skul] jracker ball," used to break up imperfect metal that is to be remelted. The magnet Used; for this lift is 5J inches in .diameter, and its weight 1,800 pounds. It requires 4 feet 6 inches head-room. When this great weight has been lifted high in the air, and the current is turned off and the "skull cracker ball" has fallen, the magnet again picks it uj easily and quickly without any assistance fropr any one on the ground.

As a rule, a man on the ground is oot necessary where a lifting magnet Is employed, for the reason that there are no chains, slings, or hoisting blocks to be fitted about tht weight to be lifted^ However j then are a few instances where a ground man facilitates the work of the magnet. One of these Is the lifting of an ingot, say, of 6,000 pounds. If a ?rpund man places the magnet, two of these ingots can be lifted ; otherwise only one at;a time.- For if two Ingots are to be lifted simultaneously, they must be in proper position, on account of their weight, for the magnet to grip them in their right olace. ;

Instead of the round magnet just 'escribed, a rectangular magnet is ised in lifting a "sow and pigs" at the furnaces. When thus lifted from the sand they are not white hot, 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 cut 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 of magnet is also used for holding steel plates in place to be riveted in the construction of ships* 1 For two or three years past a number oi 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 of the sheet may dip down to an angle of 45 deg.and still the sheet be held tightly by the magnet.

The use of the lifting magnet makes It possible to pile acrap 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 done with great'rapidity. In loading from waggons to storage piles, the work of bours when done by hand is reduced to a few minutes by the use of the magnet.

With the 52-inch magnet, 600 to 800 tons of scrap are easily handled in a day of twenty-four hours at an openhearth furnace, even when four hours are allowed 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 60 inches in diameter and will handle "skull cracker balls" weighing 30,000 ta 50,000 pounds. — " Popular Science Sittings."

Critic (as the composer plays his last piece): "Very fine indeed. But what is that passage which ma'tc the cold chills run down the back ?"

Composer: "That is where the wanderer has the hotel bill broug'i! to him."