The morning times., 1896-05-17
MAGNETS THAT LIFT TONS
Growing USeOf Electric Cranes
In FOundrieS and ArSenalS.
GREAT SAVING OF LABOR
No Sings Required Especially Con-
venient in Handling Heavy Shot.
Safe and Effective.
downright. 1861

tCOpyTISnI, lO5o.1
BY means OF the electric crane and the
electro-magnet which were introduced into
this country and recently exhibited before
the American Society OF Mechanical Engi-
ueers, II is claimed that three men can
now do in fifteen minutes the same amount
OF worK wnlcn Iorineriy taxed Iue streugtn
OF six men for ninety minutes. II is found
Invaluable In working Will pig iron. heavy
castings, and immense boiler plates.
1t . ,rIics uy engineering experts that
| these lifting magnets will soon replace
the present forms Of the derrick and tray-
| cling crane. Preparations are being made
| to introduce this device in the great Car
| negie works at PttsDurg and it's practical
| workings are being very carefully watched
| by at least half a dozen large manufacturers
| throughout the country.
| AT first sight, it appears odd that a
| small coil OF metal weighing only about
| forty-fiye pounds can, by That strange force
| known as Rgnetic influence, aided by the
| equally mysterious power of electricity
| lift tous OF iron with no apparent grip upon
| the weight TO be lifted. 1t has been proved
| by experiment, however, that such an
| electro-magnet can lift seventy-two times
| its own weight
USED IN ENGLAND.
| In England, the electric crane and electro
| magnet are In use in u number OF places-in
| particular at the WoolWich Arsenal and
at the Sandycroft works. Those in use at
! the WOolwich Arsenal were designed by
| All officer in the British army and greatly
simplify the work OF lifting and moving
heavy shot and plates OF iron and steel
Particularly is the electro-magneU OF value
In Ifting heavy shot, as previous to their
use Workmen experienced no end OF
trouble In getting sings securely around
the shot, IL was a long and heavy task,
and required the labor OF many men.
Now tile electro-magnet is lowered by
the magnetic crane and simply laid on
the side of the shell To be raised: the
turning OF small lever at the base OF the
crane switches on the current, and the
work Is done. Here the new APPARATUS
enables three nen to do the work which
formerly required niue men
The construction OF the crane and he mag
net IS peculiar, aud its inventors claim
that there Is less chance of q break than
Wien the old-rashinned tackle was used
Indeed, so far as is Known no accidents
with the new method have thus far &C
CURED.
RESEMBLES A SWINGING CRANE.
The electric crane looks very much like
an ordinary swinging crane Ii is CON
structed OF the best steel, the frame be
ing comparatively light, but of a strength
far IN excess OF any strain which will
ever be put upon 1t. From the base or
an upright steel beam a long steel arm
projects, first upward at an angle Of 46
degrees; then, with bend upward a nd out
ward, 1t extends for a distance nearly vice
the length OF the supporting beam. Two
steel rous reaching from the top or ne beam
10 the crane act as supports or holds One
Is attached TO the crane abuut.a third of tho
way from the base, and Just at the bend
While the other is attached To the upper
end OF the crane.
The Wire through which the electric cur
rent is carried from the battery at the
base OF tue crane to the magnet runs uD
along the upright beam and across the
upper support TO the end of the crane,
! then over a small wheel to the end of
t1ttIe chain 10 which is attached the lifting
magnet. Duplicate wires are used to pre-.
vent any possible accident in case the
wire should foul with anything or in any
way be broken. The swltch-b board gov
ernlng the current is placed II the base
In lifting a weight of $500 pounds a
current of from three TO four amDeres at
from 20 TO 80 volts is used The mag
nets vary in size and weight from com
parativeiy small ones weighing 45 pounds
TO those having a weight of $50 pounds,
but the lifting power OF the ma gnet is
not always in proportion 10 its size.
NUMBER OF IDEAS PATENTED.
The body or core OF the magnet used
In lifting steel shells or circular pieces of
metal is shaped like an inverted L and
closely bound with wire, the winding
being protected by brass flanges and by
thick covering of brass. The two ends
OF the wire winding are led TO duplicate
terminals, where they are joined to the
two wires from which they receive the
current Through the center OF the Magnet
run two bars. 10 which are attached the
rings by which the ma gnet is attached to
the hook at the end of the pulley on the
lifting chain.
There are Il number of different patents
already out on electro ma gncts and cleo
tric cranes. Some of the cranes are in
tented to he permanent fixtures in mills
and iron works, while others. for lighter
work, are known as movable cranes and
can be used on flat cars or in yards The
movable cranes are balanced by a coun-
terweight placed at the base of the up-
right beam, but the general idea is the
same in all.
The magnets differ more than the
cranes, those in use in rolling mills and
foundreS being very different in shape
from those used i'll arsenalS and other
places where the greater part OF the ma
tenal to be lifted is spherical or cyin-
drCal in form. For use in factories and
yards the magnets vary in size from 100
to 2T5 pounds. They are usually made
with what are known as limbs. which
are simply two projections from Il steel
cross bar. Such is the one in use at the
SandycrOft works in England. In this
magnet the limbs are wound with wire.
and on the cross-bar is switchboard
for throwing the current on and off. II
is used in lifting pieces of iron and steel
varying in weight from 100 pounds to
two tons. Before the advent of the
eiectroma gnet the packing of such masses
of metal was work of the hardest kind:
but now two men can do in quarter
of an hour what it formerly took six men
an hour and an half to do. Attached
to the cross-bar. between the limbs of the
magnets. is a hook from which q sling
can be suspended for use in lifting non
ma rDp tic substances