Interior core protector

An interior core protector for protecting the interior of a coil of material, e.g., coiled sheet steel, from damage is disclosed. The core protector includes a pair of overlapping formed angular paperboard members each having a series of spaced die cuts in one leg thereof permitting the angular members to be bent to conform to the inner diameter of the coil. The cuts in one leg are offset from the cuts in the other leg such that when the protector is bent for placement in the interior core of the coil and the width of the cuts increases, a paperboard segment of one member nevertheless overlies the cut in the other to provide protection for the material about the full circumference of the interior core. The core protector is characterized in part by economies of materials used, economic use of such materials, and economies of shipment.

BACKGROUND OF THE INVENTION 
This invention relates to an interior core protector and, more 
particularly, to the protection of the interior material in a roll of 
coiled material, for example, a coil of sheet steel. 
It is well known that sheet steel, e.g., that which is used extensively in 
the automobile industry, is placed in large coils by the steel producer 
for shipment to the user. These coils weigh upwards to 15 tons and include 
a center core or opening therethrough. It is quite common in strapping of 
the coil to prevent its uncoiling to place steel straps through the center 
core and about the outside of the coil. Typically, at least two and 
sometimes three or four of these straps spaced about the coil are used. 
Furthermore, it is quite common in the transport of these heavy coils, 
particularly in their loading and unloading from trucks and railway cars, 
to use a C-hook which comes down and passes through the center core and is 
then raised to engage the interior surface of the material to lift the 
coil on and off the truck or railway car. In doing so, the C-hook often 
damages the metal particularly by bending of the edges of the material 
located at the center of the coil. That is, when the C-hook is placed 
through the coil and raised upwardly into engagement with the material, it 
is rare that the hook ever engages the material at both edges with equal 
pressure. Rather, the hook typically first engages one edge and then the 
other. When this happens, the pressure of the hook on the material causes 
its bending. This bent material, of course, is not usable and must be 
scrapped. It is not uncommon for the user to have to scrap 30 to 50 feet 
of the sheet metal because of such damage. 
In addition to damage by the C-hook in loading and unloading of the coil 
material, it is also quite common for the transporter to throw a chain 
through the interior core of the coil to secure the coil on a truck or 
railway car. This likewise causes damage to the edges of the material 
causing waste and scrap of what would otherwise be usable material. 
It has been suggested therefore to provide some form of protection for the 
material about the interior core of the coil. However, prior attempts to 
provide such protection have not been wholly successful either 
economically or in terms of providing the protection needed. 
SUMMARY OF THE INVENTION 
It is among the principal objects of this invention to provide an interior 
core protector for positioning about the inner diameter of a roll of 
coiled material to protect the material from damage that is relatively 
economic to produce, that provides full protection for the material about 
the 360.degree. circumference of the interior core, and that provides 
advantages in terms of economic use of materials and economies of shipping 
to the customer. 
In the presently preferred form of the invention, the interior core 
protector includes a pair of overlapping formed angular paperboard members 
which are manufactured in a flat, i.e., non-arcuate configuration. One leg 
of each of the members includes a series of cuts spaced along its length 
and extending from the free edge of the leg to the angle joining the legs. 
These cuts permit bending of the core protector to conform to the inner 
diameter of the coil. The cuts in the legs of one of the members are 
offset with respect to the cuts in the other member such that when the 
protector is bent to conform to the inner diameter of the coil and the 
spacing along each cut correspondingly increases, i.e., the cut opens up 
when the protector is bent, there is nevertheless provided a section of 
paperboard material overlapping each cut. The core protector thus provides 
protection for the material about the complete circumference of the inner 
core of the coil. Thus, when a chain is thrown through the core or a 
C-hook passing through the coil engages the material, the edges of the 
inner length of the material are protected from damage. No special 
locating or positioning of the C-hook, for example, is needed. Rather, 
since 360.degree. protection to the edges of the material at the inner 
core is provided, the coil may be grasped at any location. 
Among the many advantages of the present invention are the protection it 
provides the coiled material including protection to the edges of the 
inner length of material around the entire circumference of the inner 
core, the economy of the materials of construction in that the protector 
is preferably formed of relatively inexpensive paperboard, the economic 
use of this material in that there is very little waste in forming the 
protector, the rigidity of the formed angular members whereby when the 
protector is placed in the core the flanges closely conform to the 
material and do not fall down or tend to flatten out, the fact that the 
angular members once bent tend to want to straighten out and thus when 
placed in the core the protector tends to urge itself into engagement with 
the inner diameter of the coil, and the fact that the protector can be 
economically packaged and shipped merely by stacking up a series of 
protectors one on another and shipping them in a straight or non-arcuate 
position. This results in full utilization of shipping capacity with no 
waste of space. 
These and other objects of the present invention will be apparent from the 
following detailed description, reference being had to the accompanying 
drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, there is shown a coil of sheet material 10, for 
example, a large and heavy coil of sheet steel of the type typically used 
in the automobile industry, for purposes of illustrating the environment 
in which the present invention finds particular applicability. As shown in 
FIG. 1, the sheet material is coiled to form a large roll of material 
having a open center core 12. A series of steel bands 14 are placed 
through the core 12 and about the coiled material to keep the material 
from uncoiling. As is common practice in the industry, paperboard angles 
16 are provided on the outer diameter of the coil 10 to keep the edges of 
the sheet steel from cutting the steel straps. The interior core protector 
20 of the present invention is adapted to be placed about the inner core 
12 of the coil 10 on both sides of the coil, i.e., two protectors are used 
for each coil. Thus, when the coil protectors 20 are positioned in the 
core 12 of the coil 10 as shown in FIG. 1, the protectors 20 form a 
protective barrier around the inner edges of the coiled material. 
Referring in addition to FIG. 2, the core protector 20 is formed of two 
like overlapping formed angular paperboard members 22 and 24. Each member 
22 and 24 includes a pair of legs 22a and 22b and 24a and 24b, 
respectively, which are generally at right angles one to another. The 
protector 20 is preferably formed of a relatively inexpensive material 
such as paperboard. A presently preferred thickness of the protector is on 
the order of 0.120 inch, this being the total thickness of the protector 
or sum of the thicknesses of the two members 22 and 24. One leg 22b and 
24b of each member is die cut to provide a series of generally equally 
spaced cuts 26 extending from the outer edge 28 and 30, respectively, of 
each leg 22b and 24b to the angle 32 and 34, respectively, at which the 
two legs 22a and 22b and 24a and 24b of each member meet. These die cuts 
26 permit the protector to be bent in the generally circular configuration 
shown in FIG. 1. The two members may be joined by an adhesive placed 
between the overlapping uncut legs 22a and 24a of the angles 22 and 24. 
In a presently preferred form of the invention, the protector 20 is about 
75 inches long to cover the circumference of a 24-inch diameter core and 
each leg is approximately 3 inches long. Thus, when the protector is bent 
to conform to the diameter of the core and is placed in use as shown in 
FIG. 1, an area of protective paperboard extends interiorly 3 inches from 
the outer edge the coil from both sides of the coil and 3 inches radially 
outwardly along the face of each side of the coil 10. 
As shown in FIG. 2, the cuts 26 in one leg 22b of one member 22 are offset 
from the cuts 26 in the leg 24b of the other member 24. Thus, when the 
protector 20 is bent into its generally circular configuration and the 
width of the cuts 26 correspondingly widens, as shown in FIG. 3, there 
nevertheless is maintained at each cut 26 a section of protective material 
which overlies the openings caused by the cuts. As shown in FIG. 3, a 
section 22b overlies the cut 26 in leg 24, and a section 24b overlies the 
cut 26 in leg 22. Thus, even though the cuts 26 open up on bending of the 
material, because of the overlapping legs 22b and 24b there is maintained 
protective paperboard material about the entire circumference of the coil. 
It is important to note that legs 22b and 24b are not glued together prior 
to bending of the core protector since the sections between the cuts 26 
must be free to slide over their overlying sections to permit bending of 
the protector. However, in some cases, particularly with lighter material, 
it may be desired to adhere the overlying sections together after bending 
so that the sections do not fall or extend outwardly where possibly they 
may be torn off during use. Both objectives may be accomplished by 
providing the surface of leg 22b facing leg 24b with a layer of pressure 
sensitive adhesive covered with a removable release paper. The release 
paper prevents the facing legs from adhering before bending. To form the 
core protector to the shape of the interior core of the coil, it is merely 
necessary to remove the release paper thereby exposing the pressure 
sensitive adhesive, bend the protector to its generally circular 
configuration, insert the protector in the coil, and then press the legs 
22b and 24b together. 
There exist other alternatives for increasing the rigidity of the core 
protector and particularly the legs 22b to maintain them upright and in 
close relation to legs 24b. As shown in FIG. 4, a bendable but relatively 
rigid piece of material such as a piece of sheet steel 40 of 0.020 inches 
thickness, for example, may be laminated between the paperboard layers of 
member 22 so that when angular member 22 is formed it includes therein the 
angular member 40 having legs 42a and 42b extending respectively along 
legs 22a and 22b of member 22. Preferably, legs 42a and 42b terminate 
short of the ends of legs 22a and 22b so as not to expose any potentially 
sharp metal edges. The sheet steel 40 is likewise die-cut at 26 to permit 
spreading between the legs 22b when the core protector is bent to its 
arcuate shape in use (FIG. 5). The steel sheet 40 being relatively stiff 
readily serves to hold the die-cut legs 22b upright and close to legs 24b. 
With the protectors 20 in place in the core 12, when the coil is grasped, 
for example, by a C-hook, or a hold down chain is thrown through the core, 
protection of the edges of the inner length of the coiled material is 
provided about the full circumference of the inner core. Thus, the core 
protector 20 provides for complete protection along the entire 360.degree. 
circumference of the core, and the C-hook can therefore enter the core 
from any position about the core. 
One of the advantages of the present invention is that when the protector 
20 is bent to conform to the diameter of the core 12 the resiliency or 
memory properties of the paperboard material from which the protector is 
made tends to want to straighten the material back to its flat or unbent 
condition. This is desirable since it causes the protector to expand 
outwardly and, as a result, to tightly engage the material about the inner 
core. Thus, there is no need for any special provision for either locating 
or holding the core protector in position before strapping of the coil. 
Second, since the core protector is made of a formed angular paperboard 
member, the angle between the legs is rigid and maintains itself in both 
the unbent and bent conditions of the core protector. Thus, the legs 
having the cuts 26 tend to lie flat against the surface of the coil as 
contrasted to falling down as would be case if a flat material such as 
paper were only creased to lie against the face of the coil. Third, in 
addition to being made of relatively inexpensive paperboard material, the 
core protector makes very economic use of this material. That is, there is 
no waste of material as would otherwise occur if the core protector were 
to be made as a annular piece. This would require cutting of an annulus 
out of a flat square sheet which would waste the core as well as the 
material lying outside the outer diameter of the annulus. Thus, a savings 
in material on the order 60% is realized with the core protector of the 
present invention. 
Still further, in the preferred form of the invention, the core protector 
can be packaged and shipped in its flat or unbent condition (as shown in 
FIG. 2) such that the core protector must be bent by the user to fit it 
into the coil. This permits the protectors to be economically packaged and 
shipped merely by stacking them one on another. There is none of the 
wasted space which would be occasioned if annular protectors were shipped. 
Thus, the core protector of the present invention provides not only 
excellent protection for the coiled material but is relatively economic to 
produce and to ship. Since these core protectors are a disposable item, 
this is very important to the producers of the coiled material. 
Although the presently preferred form of this invention utilizes paperboard 
as the material of construction for the reasons stated above, it will be 
appreciated that other materials such as sheet steel or other metal may be 
used instead if so desired.