US2990057A - Package of sheet metal and process for making the same - Google Patents

Description

J. T. NICHOLS June 27, 1961 PACKAGE 0F SHEET METAL AND PROCESS FOR MAKING THE SAME Filed Aug. 29, 1956 5 Sheets-Sheet 1 IN VEN TOR Jo/m T. NICHOLS K "W ATTORNEYS.

June 27, 1961 J. T. NICHOLS ,0

PACKAGE 0F SHEET METAL AND PROCESS FOR MAKING THE SAME Filed Aug. 29, 1956 5 Sheets-Sheet 2 Tia. Ev.

INVENTOR. JOHN T. NICHOLS Ly "W AT TORNEYS.

June 27, 1961 J. T. NICHOLS 2,990,057

PACKAGE OF SHEET METAL AND PROCESS FOR MAKING THE SAME Filed Aug. 29, 1956 5 Sheets-Sheet 3 7 f8 INVENTOR.

JOHN TINIcHoLs BY AQVM MW ATTORNEYS.

June 27, 1961 J. T. NICHOLS 2,990,057

PACKAGE 0F SHEET METAL AND PROCESS FOR MAKING THE sAME Filed Aug. 29, 1956 5 Sheets-Sheet 4 IN V EN TOR. JOHN I NICHOI. s

ATTORNEY Jum: 27, 1961 J. T. NICHOLS 2,990,057

PACKAGE OF SHEET METAL AND PROCESS FOR MAKING THE SAME Filed Aug. 29, 1956 5 Sheets-Sheet 5 'fi iE 1-1 .13.

W i t 7e I l I I 1' 1 7e I I a l 0 I I l I l I 1 1' IE 1 1 5 i I I] 7 l i 76 A3 i r; I Hi 3 i i en I I H: /l 14 '1. l 7 a I I L i 1 2a 22 W U u INVENTOR.

JOHN i. N/cwaw ATTORNEKS' nited States This invention relates to a package of sheet metal and to a process for making the same. The invention was developed specifically for application to the packaging of sheet steel and tinplate stacked in the usual form of a plurality of layers piled on each other with mutually flush edges, and sheet steel and tinplate in strip form coiled in the usual fashion. However, the principles of the invention may be used whenever a mass of superimposed layers of sheet metal must be packaged for shipping.

Technically and commercially many designations or names are applied to what the layman would usually call sheet metal. Throughout this specification and claims the reference to sheet metal is used in the lay sense regardless of length, width, and gauge, providing the product is either stacked or coiled so as to form a mass of superimposed layers which must be bound together and protected for shipping purposes. Such a package may be stored in warehouses as well as shipped and, of course, the layers may be formed by the successive convolutions in the case of coil strip.

Heretofore this type of product has been packaged by the use of taut metal strapping or wire, using pieces of wood where necessary to prevent denting or other deformation. Paper and wood have been used to provide more complete protection. In this prior art packaging procedure it has been necessary to resort to hand-labor almost exclusively, the workmen crawling around, using lifts and the like, and in general being subjected to slow working conditions which are to some extent also unpleasant and dangerous. The prior art package itself has left much to be desired, it being well known that tinplate is subjected to Surface marking during transit, for example, and that in general it is diflicult to prevent the product from being damaged when subjected to shipping and storage conditions.

One of the objects of the present invention is to provide for packaging the described type of product by using machinery more extensively than has heretofore been possible and so that the resulting package is substantially more secure and reliable in the direction of assuring safe delivery of the product to the point where the package is opened by the consumer. Other objects may be inferred from the following disclosure of specific examples.

The accompanying drawings illustrate these examples, the various figures being as follows:

FIG. 1 is a side elevation showing the machine packaging of a stack of sheet metal;

FIG. 2 is substantially the same as FIG. 1 but shows a later phase in the packaging operation;

FIG. 3 is a perspective view showing a partially completed package;

FIG. 4 is the same as FIG. 3 but shows the package in a more complete form;

FIG. 5 is like FIGS. 3 and 4 but shows the completed package;

FIG. 6 is a plan view of an element of the package in blank form;

FIG. 7 is a perspective view showing the element of FIG. 6 formed and ready for use;

FIG. 8 is a cross section taken on the line 8-8 in FIG. 5;

FIG. 9 is generally similar to FIG. 1 but shows the manner in which a coil of strip is handled;

FIG. 10 is an inside end view of an element used to complete the coil type of package;

mars? Patented June 27, 1961 FIG. 11 is a side view of FIG. 10;

FIG. 12 is an end view of another element of the coil package;

FIG. 13 is a side view of FIG. 12; 7

FIG. 14 is a side view or elevation of the completed coil package; and

FIG. 15 shows a modification of FIG. 3.

Referring first to FIG. 1, the stack of sheet metal 1 is shown as being placed in a tray 2 which is positioned on a platen 3 which may be pushed upwardly by a hydraulic vertical ram 4 which slides in a vertical hydraulic cylinder 5. When liquid under pressure is supplied to the cylinder 5 through the inlet 6 the platen 3 rises with great force.

FIGS. 6 and 7 show that the tray 2 is simply a blank of sheet metal 2a cut to provide tabs 2b which are bent upwardly to form the tray shown in detail by FIG. 7. It is not necessary to jointogether the abutting edges of the tabs 2b although this may be done if desired.

Going back to FIG. 1, a span of sheet metal 7 with its end edges gripped by grippers 8 is positioned above the stack 1. This piece 7 has a width at least substantially equalling the extent of the stack 1 in a direction transverse to the piece 7. The length of the latter is sulficient to permit it to be bent downwardly along the edges of the layers of the stack 1 for ultimate joining to the adjacent ones of the tabs 2b of the tray 1.

The grippers 8 are very powerful and are mounted on the piston rods 9 of hydraulic tensioning cylinders 10 designed to exert a tension on the piece 7 beyond the elastic limit of the latter when each cylinder is provided with hydraulic fluid under pressure through its inlet 11. Each gripper and tensioning cylinder assembly is mounted to swing in a vertical plane by a pivotal bearing 12 which connects the assembly with a horizontally shiftable carriage 13 moved horizontally in the extending direction of the piece 7 by a nut 14 which is in threaded engagement with a horizontal screw 15. The mutually opposing ends of the screws 15 are rotatively anchored by fixed mountings 16.

The solid lines in FIG. 1 show the parts arranged for the start of the packaging operation. The stack 1 having been placed in the tray 2 may be easily swung onto the platen 3, particularly if the machinery is located conveniently with respect to the floor level. The piece 7 is placed in the grippers 8 in the same manner that a length of sheet metal is handled in connection with stretcher levelling operations.

With this set-up completed fluid is admitted to the inlets 11 so that the tensioning cylinders 10 cause the piece 7 to be highly stretched. At the same time fluid is admitted to the inlet 6 so that the platen 3 pushes the stack upwardly. The screws '15 are also rotated at the same time so that clamps 8 approach each other. These various operations are conducted in the order and manner commonly used in the metal stretch forming art. In other words, the various actions in effect are controlled so that the sheet metal piece 7 is literally stretch formed or molded in a substantially plastic condition about the stack 1, the tension stress and other forming stresses on the metal piece 7 being at one time or another substantially in excess of the latters yield point.

The first phase in the above operations is generally shown by the broken lines in FIG. 1 while FIG. 2 shows the completion. 1

It can be seen that the piece 7 is in efiect a sheet metal wrapper which is wrapped around the stack of sheet metal product under such great tension force as to literally plastically mold the wrapper into place.

During the phase shown by FIG. 2 the ends of the wrapper 7 are still held by the grippers 8 and at this time the pressure of the hydraulic fluid introduced through the inlets 11 is suflicient to keep the wrapper, or at least its vertical portions, elastically stretched. In other words, the vertical portions at least are under substantial elastic strain. The described machine further includes spot welding electrodes 17 mounted by suitable elements (not shown) so that they can swing against the portions of the wrapper 7 which now overlap the adjacent tabs 2b of the tray 2. These electrodes 17 may be provided in the form of gangs of electrodes or may be made as single transversely movable electrodes. In any event the arrangement should be such as to permit the described overlapping portions to be joined together while at least the vertical portions of the wrapper 7 are elastically stretched. In FIG. 2 an electric power line 17a is shown going to the electrode 17, the platen 3, which is made of metal, of course, being grounded by a line 17b. The automatic welding art is capable of designing this type of equipment easily. Line welding using a suitable travelling roller electrode may also be used.

The degree of stretch maintained on the wrapper 7 prior to and until completion of the Welding should be sufficient so that when the clamps 8 are released at least the vertical portions of the Wrapper 7, and possibly the entire wrapper, remains under a state of elastic strain. The strain should be sufiiciently great so that it does not disappear or unload when the package is subjected to heat such as would normally be encountered during shipping and storing. The tray should be designed so that its flat portion 2a just about fits the bottom of the stack and, therefore, does not bend when the stress is placed on the tabs 2b fastened to the wrapper 7.

It can be seen that the stack of sheet metal layers 1 is now somewhat like a stack of paper held together by rubber bands. However, the elastically stretched element is the sheet metal piece or Wrapper 7 which extends for the full width of the stack and is literally molded thereabout. The sheet metal layers are held together by the tremendous elastic forces constantly and always available because of the stretched wrapper 7. Since the latter would ordinarily be made from sheet steel the package binding force is great at all times. There is practically no chance for the individual sheets to slip relative to each other and excellent external protection is provided for all parts encompassed by the wrapper and tray.

FIG. 3 shows the package as it appears at this time and for some purposes this stage of the packaging operation may prove adequate. The downwardly projecting flanges 7a represent those portions held by the grippers 8 and they may be either bent under or sheared off as desired.

FIG. 4 shows how simply more protection may be obtained. In this case a second Wrapper 70 has been applied at right angles to the wrapper 7. The same procedure is used all over again excepting that the stack is rotated through a quarter turn to receive the second wrapper piece. Obviously the tray 2 is a part of the wrapper and all of its tabs 2b are now stretched under elastic tension unless the gauge of the metal from which the tray 2 is made is heavier than that of the wrapper pieces 7 and 7c. The parts 7a of the wrapper sheet 7 remain and the wrapper sheet 70 and the corresponding parts 7d. As described before, these may be bent inwardly and upwardly or removed by shearing. The elastic stretching of the two wrapper pieces should be proportioned preferably so that the tension on the first wrapper 7 is not completely diminished by the tension applied to the right angular wrapper 70. In all cases, the pieces 7 and 7c have widths substantially equalling the lengths of the tabs 2b which they overlap and to which they are attached in a substantially integral fashion. As shown by FIG. 4 the package now provides almost complete protection in that the stack of metal sheets or layers are almost completely encompassed by a molded sheet metal sheath under an elastically stretched condition.

The exposed corner portions of the package shown by FIG. 4 are shown in FIG. 5 as being closed by angle bars 18. These angle bars 18 may be made of light-gauge steel and spot welded in position. If the metal is light- 4 gauge it will stretch and recover with stretching and recovery of the elastically stretched wrappers, the angle bars being of relatively small cross sectional area. Alternately, these corner protecting units may be formed from heavy paper or fiber board and applied by means of a suitable adhesive.

In FIG. 9 only the pertinent elements of the previously described machine are indicated. In this case the product being packaged is a coil of metal strip 1a. The platen 2 is modified and is now in the form of a heavy standard 3a from which a circular spindle 3b projects through the open center of the coil. The tray 2 is replaced by a more appropriately shaped wrapper segment in the form of a short length of wrapper sheet metal 20. To provide the upward push on the coil a saddle beneath the coil could be used instead of the spindle 3b. The wrapper 7e encircles the coil 1a more completely than the wrapper 7 encircled the wrapper shape 1, this being largely due to the difierence in contour. The grippers 8 pull the wrapper 7e stretched elastically while the electrodes 17, or their equivalent, interfasten the Wrapper sections 2a and 72. It can be seen that the coil is elastically held under a large radial compressive force at all times during the life of the package by the elastically stretched encirclement of metal.

The result of this procedure shown by FIG. 9 might be likened to a huge can package of the evacuated type wherein the atmospheric pressure compresses the package at all times. In this case it is the elastically stretched wrapper which applies the pressure. The various layers cannot possibly slip relative to each other during shippage and storage.

Top and bottom ends 19 may be provided for this coil package. These are shown by FIGS. 10 and 11 as being stamped from light-gauge sheet metal. It is to be understood that the metal may be of any gauge depending on the protection desired. FIGS. 12 and 13 show how the encircling wrapper formed by the parts 2a and 7e would appear if removed, and it can be seen that the ends 19 can telescope over the ends of this body portion of the package. Either welding or a suitable adhesive may be used to secure the ends in place.

In FIG. 14 the completed package is shown as being vertically arranged and resting on. a circular pallet 20 to which the adjacent one of the ends 19 may be secured by an adhesive layer 21. This practice may also be used in the case of a rectangular package excepting that in such an instance the pallet would be rectangularly shaped to match the package contour. In either case the package may be picked up easily by the usual fork lift truck type of equipment and thepallet provides a skid or support at all other times.

Due to the heavy compression under which the various metal layers of the packaged product are maintained, the normal oiling or other coating practice used in the mill might desirably be modified to make certain that the consumer can separate the layers. Although the present package contemplates great compression which is continuously maintained, trouble with. separation of the prodnot should not be expected, it being remembered that tinplate, for example, is arranged with one package on top of another up to considerable heights with the result that the lowermost package has the separate layers under a compression as great as that contemplated in the case of the present package.

As was previously indicated the form of the package shown by FIG. 3 may prove to be adequate.

However, this leaves the edges of the packaged product exposed to the possibility of damage. In the modification shown by FIG. 15 these edges are protected by covers 22. These covers need not be stretch formed and may consist simply of sheets of metal having edge flanges 23 which embrace the package proper and may be spot welded to the same. This form completely encloses the packaged sheets or layers but requires only the single stretch forming operation.

All of the packages illustrated may be mounted on wood pallets 0r platforms and secured thereto by adhesive along the lines indicated by FIG. 14. The package shown by FIG. 15 is very attractive commercially since it is a relatively inexpensive form providing very complete protection. As just indicated this package of FIG. 15 normally would be mounted on the platform 20 and held in place by the adhesive 21 shown by FIG. 14, with the understanding that the platform would have the shape of the FIG. 15 package.

I claim:

1. A package comp-rising a mass of tightly superimposed layers of metal each having the thickness of sheet metal, a sheet metal wrapper wrapped about said mass and conforming substantially exactly to the thus enwrapped shape of the latter, said wrapper having a transverse width substantially as wide as said mass is transversely to said wrapper, and means for interconnecting the ends of said wrapper, the latter being permanently elastically stretched and under a state of elastic strain, said strain being sufficiently great to prevent it from completely disappearing or unloading when the package is subjected to heat such as would normally be encountered during shipping and storing.

2. A package comprising a mass of tightly superimposed layers of metal each having the thickness of sheet metal, a sheet metal wrapper Wrapped about said mass and conforming substantially exactly to the thus enwrapped shape of the latter, said wrapper having a transverse width substantially as wide as said mass is transversely to said wrapper, and means for interconnecting the ends of said wrapper, the latter being permanently elastically stretched and under a state of elastic strain, said strain being sufiiciently great to prevent it from completely disappearing or unloading when the package is subjected to heat such as would normally be encountered during shipping and storing, said layers being in the form of a stack of flat metal sheets and said means being in the form of a sheet metal tray having upturned side Walls snugly fitting the bottom of said stack, said wrappers ends being interconnected by being connected to said side walls.

3. A package comprising a mass of tightly superimposed layers of metal each having the thickness of sheet metal, a sheet metal wrapper wrapped about said mass and conforming substantially exactly to the thus enwrapped shape of the latter, said wrapper having a transverse width substantially as wide as said mass is transversely to said wrapper, and means for interconnecting the ends of said wrapper, the latter being permanently elastically stretched and under a state of elastic strain, said strain being sufficiently great to prevent it from completely disappearing or unloading when the package is subjected to heat such as would normally be encountered during shipping or storing, said layers being in the form of convolutions of a coil of sheet metal strip, said wrapper being wrapped about said coil circumferentially thereof, and said means being in the form of a short length of sheet metal fitting the side of said coil and to which said wrappers ends are connected for interconnection thereof.

References Cited in the file of this patent UNITED STATES PATENTS 874,779 Marks Dec. 24, 1907 1,646,982 Schlafly Oct. 25, 1927 1,732,619 Ryan Oct. 22, 1929 1,970,781 Stevens Aug. 21, 1934 2,321,187 Di Cicco June 8, 1943 2,342,025 Watter Feb. 15, 1944 2,585,237 Gay Feb. 12, 1952 2,661,838 McCracken Dec. 8, 1953

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