The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1904-08-19
Invention.

William A. Dunn of Duluth, for
mer superintendent Of the Ironton
Steel company of that city, has caus-
ed to be patented in this and num-
erous foreign countries a process for
increasing the strength of cross sect
Ions of Il" beams, girders, angles,
etc., beyond the limits now consider
ed practicable by iron manufacturers.
1t is a principal that iron makers
have long been seeking to solve and
is considered by those who have made
an investigation as Of immense i'm
portance. BY its use a 24-inch "I''
beam which ordinarily weighs so
pounds per foot may be made as light
as GO pounds.
Since the Iroaton company plant
closed down several years ago Mr..
Dunn has been at work %perfecting his
device and the result is that it is
now protected in Canada, Great
Britain, France, Germany and Bel
gium. as we'll as in this country.
The process is said to consist in the
main of subjecting the ingot to roller
pressure eXerted in a vertical direct
ion; the sides of the slab or ingot TO
pressure eXerted in a horizontal
direction, and, simultaneously, APP
plying roller pressures to the side
edges of the slab in an inward direct
ion, and at an abrupt angle to the
horizontal. Processes now in use
embrace much closer limits than does
the new method. on the extent to
which fanges can be forced out.
They have to be formed by hori-
zonal pressure directly on the web of
the beam, thus forcing metal lateral
ly into flange grooves. This pull on
the flanges by the grooves reduces the
former every pass instead of building
them up; and it is the heavy slope
required on the fianges to permit
metal to enter the grooves easily that
gives the comparatively heavy sect
ions.
Beams up to "A inches, columns to
6x5 inches and to 14xl2 inches to take
the place of Z-bars; girders up to "a
inches, with 6 and finch fianges,
angles and tees, slitted by a simple
device in the final passes, from chan
nels and beams-these are among the
shapes that it is claimed can be made
advantageously by this new device.
Mr.. Dunn suggests that by Sitting
channels and beams into angles and
tees double the product can be got
that is produced from any bar mill,
besides doing away with the blooming
mill. The mill is universal and will
roll plates.
The one great advantage claimed
for this process is that it will give a
beam of much lighter weight than
now produced for the same web sect,
ion; also that the process gives a
greater product than other mills III
the same time and with less labor
and that it makes the various sizes
and shapes mentioned.
One of Mr.. Dunn's several paseE5s
covers a rolling mill and cutter. Fine
special feature is that after the wide
beams or channels: which it is pos
sible to roll on the type Of structural
mill referred to above, makes theil
last pass through the regular rolls
they go to a finishing machine which
consists of a pair of rolls in which
centrally of each roll are introduced
cutter blades. These slit the bean
into two rs and the channel into two
angles as each passes through. This
invention reduces the number Of
passes of the metal, diminishing thu
cost of production and increasing thu
output and Ly the peculiar form o
the cutter blade employed finishes
the Il or angle. In addition, tin