CA1072919A

CA1072919A - Cradie pallet

Info

Publication number: CA1072919A
Application number: CA264,124A
Authority: CA
Inventors: Raymond K. Rogers
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-10-25
Filing date: 1976-10-25
Publication date: 1980-03-04

Abstract

Abstract of the Disclosure A rack which cooperates with at least one other similar rack beside it for storing a coil of sheet steel on a horizontal supporting surface, the rack comprising a pair of spaced rectangu-lar 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 coil of sheet steel is to rest. The arcuate indentation is of sufficient depth and width such that coils stacked thereon are stabilized against shifting.

Description

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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, - 1 - ~ ' 7Zgl9 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.

~C~7Z9~9 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-, .

^ 16372919 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.

- 1~7Z9~9 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 .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A series of individual racks, each rack to cooperate with at least one other similar rack in the series, for storing coils of sheet metal in stacked arrangement on a horizontal supporting surface, each rack comprising a pair of spaced rectangular end members and a pair of spaced side members fixed thereto to provide a rigid frame of parallel-ogram shape, the side and end members having upper and lower surfaces, the lower surfaces of each of the side and end members being flat and co-planar to rest on the supporting surface, the upper surface of each of end members having an arcuate indentation on which a portion of the outer circumference of the coil of sheet steel is to rest, the arcuate indenta-tion having sufficient depth and width that coils stacked on racks in the series are stabilized against shifting, the length of the end members of each rack being no greater than the horizontal diameter of the coil which is to rest thereon so that the sides of the coil resting will abut with the sides of coils on adjacent racks.

2. A series of racks according to Claim 1, wherein the arcuate indentations of each rack are of sufficient depth and width that, at each end of each arcuate indentation, the sum of the outward moments of the resultant forces exerted by the stacked coils on the coil resting thereon is less than the sum of the inward moments of the resultant forces exerted by the stacked coils on that coil resting thereon.