Note: Descriptions are shown in the official language in which they were submitted.
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Backgroun-d of the Inventi_
This invention relates to racks for storing coils of
sheet steel.
Coils of sheet steel produced in steel making opera-
tions may be of various widths and thickness. For ease of handling
and storage, great lengths of these sheets are coiled into large
cylindrical coils. These coils are usually stored in "eye
horizontal" position while awaiting further processing or shipment.
Overhead cranes are often used to transfer the coils
from or to the storage area. Many industries use steel racks to
store these coils, the racks consisting of parallel spaced bars
laid on the floor of the factory or warehouse, the coils of steel
laying transversely across these bars. Wedges or blocks are
slipped in at the base of the coils, on each side, between the
coils and the steel rack, to prevent shifting of the coils. Usual-
ly a second row of coils is stored resting on the first row. With
such steel rack storing systems, shifting of the bottom row often
occurs if the blocking has not been properly carried out, present-
ing a serious safety hazard and resulting in damage to the coils.
Efficient use of storage space is also restricted with such sys-
tems, since they normally permit stable stacking of only two rows
of coils.
Other, specialized types of racks for coils of sheet
steel, for use on flat bed trailers and the like, have been pro-
posed by Stoneburner, in United States Patent No. 3,724,675, issued
April 3, 1973 and Almasy in United States Patent No. 3,460,684,
issued August 12, 1969. These coil racks are designed to support
only individual coils. They would not support without damage or
shifting a number of rows of stacked coils.
Other prior art references of interest are Bayers,
United States Patent No. 3,084,803, issued April 9, 1963 and
Hancock, United States Patent No. 3,430,773, issued March 4, 1969,
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both of which describe and illustrate locking racks for beams of
textiles.
It is an objeet of the present invention to provide a
rack which cooperates with similar racks to permit stacking of
two or more rows of coiled sheet steel. lt is a further object of
the present invention to provide such a rack which will store such
coils more securely and reduce the danger of shifting of stored,
stacked coils.
Summary of the Invention
In accordance with the present invention, there is pro-
vided a raek which cooperates with at least one other similar rack
beside it for storing a coil of sheet steel on a horizontal sup-
porting surface, the rack comprising a pair of spaced rectangular
end members and a pair of spaced side members fixed thereto to
provide a rigid frame of parallelogram shape. The side and end
members have upper and lower surfaces. Their lower surfaces rest
on the supporting surface. The upper surface of each of the end
members is parallel to the supporting surface and has an arcuate
indentation on which a portion of the outer circumference of the
eoil of sheet steel is to rest. The arcuate indentation is of
sufficient depth and width such that coils stacked thereon are
stabilized against shifting. In its broadest sense, the depth
and width of the areuate indentation must be of sufficient depth
and width that, at eaeh end of each arcuate indentation, the sum
of the outward moments of the resultant forces exerted by the
coils on the coil resting thereon is less than the sum of the in-
ward momentsof the resultant forces exerted by the coils on the
eoil resting thereon.
The length of the end members of each rack is prefer-
ably no greater than the horizontal diameter of a coil to rest
therein so that the racks and coils may be arranged with sides of
the coils in the first row in abutting relationship.
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Description of the Drawings
Other obJects and advantages of the present invention
will become apparent upon reading the following detailed descrip-
tion and upon referring to the drawings in which:
Figure 1 is a perspective view of a rack in accordance with
the present invention,
Figure 2 is a side view of a series of racks above which
three rows of coils have been stacked;
Figure 3 is a schematic diagram illustrating the factors on
which the length and depth of the arcuate indentation of racks in
accordance with the present invention depend for two levels of
stacked coils.
While the present invention will be described in con-
nection with a preferred embodiment, it will be understood that it
is not intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications
and equivalents as may be included within the spirit and scope of
the invention as defined by the appended claims.
Detailed Description of the Invention
As illustrated in Figure 1, the rack consists of end
members 2 and side members 4 having flat upper surfaces 6 and
lower surfaces 8. The lower surfaces of the side members and end
members are flush with the floor or other supporting surface to
provide maximum support.
End members 2 have arcuate indentations 10 centered
therein, on which a portion of the outer surface of coil of sheet
steel 12 rests. The depth and width of indentations 6 are suffi-
cient that coil 12 resting thereon, and any coils stacked as, for
example, in Figure 2, will be stable and will not shift. A series
of racks according to the present invention may be expected to
stack, for example, three rows of coils, each coil weighing forty
to fifty thousand pounds. In such a case, each rack should be de-
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signed to carry up to one hundred and twenty to one hundred and
fifty thousand pounds. Suitable steel or hardwood materials may
be used in the construction of the racks. While three rows of
stacked coils have been illustrated in Figure 2, additional rows
may of course be stacked where load limitations of the racks and
height limitations of the storage facilities are not exceeded. As
can be seen in ~igure 2, to ensure stability of the coils stacked
on a series of racks, preferably at least in the lowest row, coils
resting on the racks, are arranged with sides abutting each other.
As also can be seen in Figure 2, the length of the front and end
members of each of the racks is preferably less than the horizontal
diameter of the coil resting thereon.
In view of the extremely heavy weights to be supported
by such a rack, it is essential that the arcuate indentation of
the rack be of sufficient depth and width that the stacked coils,
and particularly the coil resting therein, be stable and not shift
during storage. In Figure 3, two racks 20 and 22 in which coils
24 and 26 rest respectively are illustrated, a third coil 28 stack- `
ed above and resting on coils 24 and 26. It is preferred, accord-
ing to the present invention, that the arcuate indentation has a
radius of curvature of about the same as (as shown in Figure 3)
or greater than that of the circumference of the coil which rests
therein. The radius of the outer circumference of coils 24 and 26
is shown to be rl, as is the radius of arcuate indentation XY of
rack 20 (arc s). The radius of the circumference of coil 28 is
r2. In determining the length and depth of arcuate indentation XY,
or length of arc s, according to the invention, this arcuate inden-
tation must have sufficient depth and length such ~hat, at X or Y,
for rack 20, the sum of the outward moments of the resultant forces
(i.e. "outward" in the sense of acting away from the center of the
front or end of the rack in which the indentation appears) exerted
by the coils on coil 24 must be less than the sum of the inward
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achieve full and even support of the weight of the coil on the rack
and to further reduce the tendency of the coil resting therein to
shift. As a typical example of dimensions suitable according to
the present invention, a rack having front and end members 36
inches long might have a central arcuate indentation 26.2 inches
in arc length, with radius 25 inches, to support a coil having a
circumferential radius of about 25 inches.
Thus it is apparent that there is provided, in accor-
dance with the present invention, a rack for coiled steel, which
fully satisfies the objects, aims and advantages set forth above.
While the invention has been described in conjunction with speci-
fic embodiments thereof, it is evident that many alternatives,
modifications and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it
is intended to embrace all such alternatives, modifications and var-
iations as fall within the spirit and broad scope of the appended
claims.
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moments of the resultant forces exerted by these coils on coil 24. .
For example, when considering this requirement insofar as the in-
ward and outward moments at point X (at the end of arc s in rack 20)
are concerned, arc s must be of sufficient length such that the com-
ponents of weight of coils 24, 26 and 28, acting in a counter-
clockwise direction about point X must be less than the sum of the ::
clockwise moments exerted by the relevant components of the weight ~.
of coil 24 and coil 28 acting about point X.
Assuming coil 26 exerts no forces contributing to counter-
clockwise mbment on coil 24, this means: .
W3 cos T x a = or ~ Wl x B,where l and 03 are the centers of gravity of coil 24 and coil 28
respectively, Wl and W3 are the weights of coil 24 and coil 28 res-
pectively, P is the point of contact between coil 24 and coil 28,
through which point the weight of coil 28 may be imagined to act,
angle T i9 the angle between the vertical and 03P, a is the per-
pendicular distance between x and the extension of the line 03P
and b is the perpendicular distance between X and the vertical
line drawn through l~
In a similar manner, at point Y, the sum of the moments
of the forces tending to produce clockwise movement of coil 24
about point Y must be equal to or less than the sum of the moments
of forces tending to produce counter-clockwise movement of coil 24
about that point for stability to be achieved.
These forces and moments may readily be calculated in
a given situation to either permit calculation of the length of
arc s or to confirm that a rack having an arcuate indentation of
: arc length s and radius r will be stable under those conditions.
While arc s may not conform precisely to the circum-
ference of the outer periphery of a coil of sheet steel, it is
preferred that there be a maximum contact of the outer circumfer-
ence of the coil with the arcuate indentation of the rack to
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