Patent Application
20100166533
This invention relates to equipment and a method for providing a system for economically and efficiently moving large quantities of irregularly shaped, multiply bent, pieces of scrap sheet metal from an initial location, such as from a factory, in which the scrap is generated during the production of products from sheet metal, to a remote facility. During the manufacture of products from sheet metal by a process that involves stamping the product from a larger, generally flat, sheet of a ferrous metal material, large quantities of scrap pieces are produced. These pieces, such as trim or punched or bent pieces, tend to quickly accumulate in large quantity particularly in manufacturing plants in which large quantities of articles are produced. For example, during the manufacture of stamped sheet metal automobile body parts, there are large quantities of scrap trim or excess material surrounding the stamped parts. These scrap pieces generally are irregular in shape and frequently multiply bent so that they are difficult to handle. When collected together in a container these scrap pieces occupy considerable volume, most of which is empty space because of the spaces between the irregular shapes and forms of adjacent pieces.
Various efforts have been made to recycle these scrap metal pieces, usually by conveying the pieces to a recycling melt furnace where the scrap pieces are melted and ultimately reformed into new sheets. However, stamping plants where the scrap pieces are generated, usually are remote from the recycling facilities where the parts are melted in suitable furnaces. Hence, it is usually necessary to transport the. scrap pieces considered distances from the generating location to the recycling facility.
Usual shipping methods involve the use of open-top railroad freight cars or open-top truck trailers into which large quantities of scrap pieces are dumped for transportation. Also, large container boxes have been used for containing such pieces with the boxes carried upon flatbed railroad cars or truck trailers. Typically, the transportation containers, whether truck trailers or railroad cars or large boxes, are capable of carrying considerably more weight of metal scrap than can be placed within each container when the individual pieces are loose. Hence, it is desirable to compact the pieces tightly together so as to utilize the maximum amount of the volumetric capacity of the shipping container. The more the container carries, up to its maximum weight, the greater the savings in the cost of shipping.
Thus, techniques and machinery have been developed for compressing loose pieces of scrap sheet metal into large bales or wafers which reduce the volume of space for moving large quantities of pieces.
An example of a system for compacting loose pieces is disclosed in U.S. Pat. No. 7,377,214-B2, issued May 27, 2008 to Donald R. Schomisch and Jonathan A. Little, entitled “Apparatus and Method for Temporarily Compressing Loose, Multiply Bent Pieces of Scrap Sheet Metal into Compacted Wafers.” That patent discloses equipment wherein loose pieces of scrap sheet metal are dropped into a compression chamber and then rammed by a reciprocal ram against an anvil-like door for compressing the batch of loose pieces together into compressed wafers. The wafers are discharged from the compression chamber and dropped into transportation containers for moving the wafers to a recycling facility for melting the scrap and forming new metal sheets. As illustrated in the patent, the wavers leaving the compression chamber, are dumped, helter-skelter into the container. That leaves considerable volumes of empty spaces between the wafers so that each container is not filled to its maximum weight carrying capacity. Hence, when the container travels to the recycling facility, although it may appear to be full, actually it does not hold the amount of material that it could hold.
Another example of a process and equipment for transporting loose pieces of scrap metal is disclosed in U.S. Published Application No. 2008/0156205-A1, published Jul. 3, 2008, entitled “Method for Transporting Bent Irregularly Shaped Pieces of Scrap Sheet Metal,” by Alfred George Hering. Here too, batches of the scrap sheet metal pieces are placed into a compression chamber where the batches are rammed against a vertically positioned door or anvil to form a vertically arranged wafer or slab of compressed sheet metal. The compressed wafers are pushed out of the chamber, when the door is lifted, and dropped into a transportation container which carries the wafers to the recycling facility. There the wafers may be unloaded and dropped into a melt furnace or into a pile for later moving into the furnace. The wafers are disassembled into their separate pieces so that the melt furnace receives separated pieces.
A major handling problem that arises when compacted wafers or bales are transported involves efficiently loading the transportation containers, whether a railroad car or a truck trailer, up to the maximum weight carrying capacity of the container. It is desirable to load the containers swiftly, with minimal handling and minimal labor, in order to reduce the transportation and labor costs and consequently the overall cost of recycling the metal.
Thus, the present invention is concerned with providing a system for handling heavy slabs formed of compressed together scrap sheet metal pieces, and for efficiently loading a shipping container, such as railroad freight cars or truck trailers as fully as is possible within the weight limits of the containers. This system contemplates efficiently forming and automatically placing compressed slabs in closely packed stacks and rows of slabs within the containers. Rather than merely dumping the slabs, stacking the slabs into stacks and rows of stacks avoids spaces between them as well as avoids possible shifting of the cargos during movement of the containers.
This invention is essentially concerned with equipment and methods for efficiently converting very large quantities of loose, irregularly shaped and bent pieces of scrap metal into tightly compacted slabs which are automatically transmitted from compression equipment into cargo shipping containers, such as conventional railroad cars or trailers or the like, and automatically packed within such containers in a way that uses virtually all of the available volume of the container. In general, the equipment comprises a compressor which receives batches of large quantities of scrap sheets which are rammed against a vertical plate or base to form upright, relatively thin, but large and wide, slabs. These slabs, when the plate is moved away, tip or tumble out of the compressor upon a table. The table is normally sloped downwardly so that each slab slides down the table a short distance. Then, a second slab is formed and is tipped over onto the table into end-to-end contact with the original slab. This forms a pair of adjacent, end-to-end, slabs.
After the two slabs are positioned upon the sloped table, the table is pivoted upwardly into a horizontal position. Then a large electromagnet is arranged over the slabs. Preferably the magnet is of a size and shape to substantially cover both slabs simultaneously. The magnet is suspended from an overhead crane so that when the magnet attaches to the pair of slabs, the slabs are lifted upwardly from the table. The table then returns back to its sloped position. Simultaneously, the magnet is moved by the crane, laterally of the table over the open top of a railroad car or trailer or other similar container. The magnet is then lowered to position the pair of slabs neatly within the container. By repeating the cycle, stacks of slabs are formed in the container. Another stack is formed along the side of the first stack. Then, by moving the container forwardly, such as by indexing a railroad car along the track the distance equivalent to the length of a pair of stacks, the process is repeated so that adjacent rows of stacks are formed along the length of the container. Hence, the container is completely filled by the rows of stacks, with virtually no empty spaces between the stacks up to the maximum weight carrying capacity of the container. In the case of a railroad car, filling the entire car close to the level of its open top normally would be within the weight carrying capacity of the car.
The container may then be transported, such as by rail if a railroad car, or by highway if a truck, to a recycling facility. There, the stacks may be unloaded by utilizing a similar magnetic and crane system for placing the slabs upon the ground for storage or for moving the individual slabs directly into a conventional melt furnace. The slabs may be disassembled at the furnace by applying a sufficient impact force and preferably some vibration forces to the slabs to shake the constituent parts thereof apart so that they individually fall into a molten pool of metal in the furnace.
A major object of this invention is to provide a system by which the loose pieces of scrap sheet metal are compacted together into unitary, heavy slabs which are closely stacked into shipping containers, preferably by an automatic system involving minimal labor and time for the loading process. Since the stacking enables shipping containers that are loaded close to their maximum weight carrying capacity, the number of containers, such as railroad cars or the like, is reduced to a minimum. Also, the system may be operated automatically so that the labor costs are substantially reduced.
Again, an object of this invention is to substantially reduce the cost of handling and transporting the scrap metal generated in a typical sheet metal processing plant where the scrap material is to be recycled at a remote location, by reducing the expense of handling the material between the point where it is generated to the point where it is transferred to the recycling facility.
Another object is to facilitate the loading of railroad cars or trailer trucks with the scrap metal generated at a large volume sheet metal manufacturing facility and especially to enable the loading to proceed automatically, around the clock, with virtually no human labor required.
An additional object of this system is to provide for continuous, that is, uninterrupted, flow of scrap pieces to the compressor from the generating source, while intermittently ramming predetermined size batches in the compression chamber by temporarily accumulating incoming scrap pieces upon the upper surface of the ram as the ram moves forwardly to compress a batch within the compression area, and then automatically dropping the accumulate pieces into the compression area as the ram is retracted.
These and other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part. Now, referring to the drawings:
Extending forwardly of the compressor is a table or platform 15 which receives slabs that are discharged from the compressor. The table includes an end extension portion 16 which may act as a stop for slabs sliding down the table or, alternatively, as a steep, downwardly sloped, portion of the table for discharging slabs from the table. The table is normally tilted at a downward angle and can be raised into a horizontal position as indicated in dotted lines in
Returning to
On one side, approximately parallel to the compressor and the table, is a railroad siding upon which open-top railroad freight cars move. The cars 25 travel along railroad tracks 26 and can be moved in conventional manner along the tracks beneath the crane 21 and the magnet 20.
On the opposite side of the compressor, a trailer truck 28 having an open-top conventional trailer 29, pulled by a tractor 30, rests upon a roadway 31.
In general, slabs 35, composed of numerous compressed together pieces of scrap sheet metal, are formed in the compressor initially. Then each slab falls from the compressor upon the table 15 from which it is lifted by the electromagnet and transferred into either the railroad car or the truck, as desired.
The horizontally reciprocating ram 45, which is driven by a horizontally arranged ram rod 46, is arranged within the housing. The rod extends to the rear of the chamber 39 and is powered by a conventional hydraulic power system 47.
A horizontal cover sheet or plate 48 is secured to the ram and extends rearwardly therefrom. Side braces 49 made of roughly triangularly shaped metal plates rigidify the ram and horizontal plate 48.
The housing 38 is provided with an inlet or feed opening 50 located in the upper wall 51 above the collection area 40. Scrap metal pieces 13 are fed or poured through the opening into the collection area of the compressor interior chamber. During forward movement of the ram for ramming pieces of sheet metal against the backing plate, the upper horizontal plate of the ram closes the feed opening of the compressor. However, the conveyor system 11 which supplies the separated pieces 13 of sheet metal continues to operate, without stop, depositing, pieces of sheet metal upon the upper surface of the horizontal sheet 48 as the ram is moved forwardly for compressing the batches of pieces collected in the collection area against the backing plate 42. The scrap pieces may accumulate temporarily as the ram moves forwardly. Then, when the ram retracts a scraper 54 causes the accumulated pieces to drop off the ram sheet 40 into the collection area of the housing.
The backing plate or closure 42 may be raised and lowered, by a suitable hydraulic lift 43 formed of conventional hydraulic pistons, piston rods and hydraulic cylinders. Those are conventional, commercially available parts. Thus, when the closure is lifted up the loose pieces at the opening 50 are still accumulated upon the sheet 48. Thus, only when the ram is retracted, does a new batch of pieces fall into the compression area.
After a slab is formed within the compressor and closure 42 is raised, the slab is pushed outwardly through the opening 41. The slab tilts forwardly and drops down upon the downwardly sloped table or platform 15. Then the table or platform is swung upwardly (shown schematically) into a horizontal position (see
The operation of the system is shown schematically in a series of steps, 1-9 inclusive, illustrated in
Step 1 schematically illustrates the loading of scrap pieces into the compression or collection area of the compressor housing through the opening 50 in the upper wall 51 of the housing. The ram 45 at that point is retracted to allow the pieces 13 to fall into the collection area 40.
In step 2, the ram is moved forwardly towards the closure or back-up plate 42. That movement, with sufficient force, compresses the irregularly shaped, multiply bent, pieces of scrap sheet metal to bind together into a unitary slab 35. The slab is vertically arranged against the backing plate at that point.
In step 3, the backing plate or closure 42 is raised upwardly by the hydraulic lift mechanism 53, thereby clearing the opening 41 at the discharge end of the compressor chamber. The slab 35, assisted with the forward movement of the ram, moves outwardly of the opening where it tilts forwardly and downwardly to fall upon the table 15. In step 4, the slab is illustrated as lying in face-to-face contact upon the downwardly sloped table or platform. In steps 3 and 4, the ram's upper sheet blocks opening 50 to stop the feed of pieces into the collection area.
Step 5 illustrates the ram retracting toward the rear of the housing thereby unblocking the feed opening 50 in the housing and allowing scrap pieces to again fall into the collection area. While the housing opening 50 had been blocked by the horizontal sheet (step 4) scrap pieces which nevertheless were continuously fed from the conveyor system temporarily accumulate above the ram. Meanwhile, as shown in step 5, the slab 35 has slid down the table and is stopped by the upraised table extension 16. And the backing plate is lowered to close the discharge opening.
Next, step 6 shows the loading of fresh pieces of scrap in the collection and the ram preparing to move forward for the next compression stroke to form another slab.
In step 7, the second newly formed slab, is, now completed, pushed out the opening, and tilts forwardly, under gravity force, to fall flat upon the table (shown in dotted lines) and to slide down the table into end-to-end contact with the first slab. Thus, at this point there are now two slabs, arranged end-to-end on the downwardly sloped table. For example, the table may be sloped approximately 20 degrees from horizontal to implement sliding.
In step 8, the table is swung upwardly, by its lift mechanism 61, into a horizontal position with both slabs on the table arranged in end-to-end contact and horizontal. At that point, the horizontal electromagnet 20 is positioned above the pair of slabs and comes down upon them into magnetic engagement.
After the magnet engages both slabs, the magnet lifts both slabs simultaneously. Then the magnet, carrying both slabs, is moved laterally by the crane over the open-top rail car, as illustrated in
In the event that neither a railroad car nor truck is available at a particular moment when the pair of slabs are on the horizontally-arranged table, the table may be slanted downwardly forwardly again, perhaps to a further angle of 30 degrees, and its table extension 16 will likewise be swung into a downwardly angled position so that the slabs will slide downwardly off the table entirely and land on the ground 67 and remain there until removed.
The magnetic crane arranges the pairs of slabs within the container, that is, the truck trailer or the railroad car, in stacks. The stacks are arranged in parallel rows. This is illustrated in
The formation of the stacks of slabs and the rows of stacks almost completely fills all the space in the shipping container, whether a rail car or a trailer. By way of example, a typical railroad car has a weight-carrying limit of about 220,000 pounds. When the car is filled with the closely-fitted rows and stacks of slabs, almost that entire space is used so that close to that maximum weight limit is accomplished. In the case of a truck trailer, a typical weight limit is about 20 tons or about 40,000 pounds and that weight limit amount is closely reached by the stacks and rows of stacks.
A typical slab formed by this method may be on the order of 48 inches high, 43 inches wide and about 6-12 inches thick. A typical railroad open-top freight carrier has about 90 inches of transverse space so that two rows of slabs can be formed leaving a very small amount, such as an inch, on the sides of the rows to enable the slabs to closely fit easily into, and substantially fill, the space. The result is that there is almost no empty space in the container. This contrasts with shipping loose pieces or even loose slabs or slabs or wafers that are haphazardly dropped into the container where there are considerable empty spaces. The result is that the cost of shipping, and the number of containers, such as railroad cars or trailers, required for a particular place, is substantially reduced. Consequently the cost of transferring the scrap from its source, such as the factory where the scrap is generated, to the recycling area, such as the melt furnaces, is substantially reduced.
Significantly, the system may be controlled by conventional programmed computers to automatically perform the cycle of forming the slabs, then forming the pairs of slabs, and next moving the electromagnet for lifting and depositing the slabs in the shipping container, so that virtually no manual labor is required to operate the system. The system lends itself to be completely automatic in operation. The selection of suitable computer controls and the necessary computer programming of the controls can be done by skilled technicians from commercially available equipment. Therefore, the controls and computers and programming are not further described here since variations may be used.
The foregoing description is for an operative embodiment and best mode known to the inventor herein. Thus, having filly described at least one operative embodiment, it is desired that the foregoing description be read as merely illustrative and not in a strictly limiting sense. I now claim:
