US20060086207A1

US20060086207A1 - Method for manufacturing counterweights

Info

Publication number: US20060086207A1
Application number: US11/257,241
Authority: US
Inventors: David Swenson
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-10-25
Filing date: 2005-10-24
Publication date: 2006-04-27

Abstract

A work piece and a method for making the work piece from a plurality of grains of substantially cohesive scrap metal grains or granules is disclosed. The method includes providing scrap metal as a raw material, gathering a predetermined amount of the raw material to form a charge, and compressing the charge under a predetermined amount of heat and pressure to provide a substantially cohesive form. To aid with the cohesion, the charge may be enclosed within a polymeric container or bag which acts as a lubricant during the compression stage and as a binder to aid in keeping the scrap metal together in a cohesive form.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to earlier filed U.S. provisional patent application Ser. No. 60/621,492 filed Oct. 25, 2004, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to the recycling of raw materials, and particularly to a method for using those raw materials in a new and unique process for making counterweights.

BRIEF DESCRIPTION OF THE RELATED ART

Many devices including cranes, forklifts and other large machinery used for lifting heavy objects, and microphone stand among other devices, use counterweights to keep the objects from tipping over when used. Counterweights are also used for other purposes such as providing a source of power. For example, grandfather clocks have a series of weights used to power the clock mechanism. Traditionally these weights have been made from cast iron or standard commercial grades of steel, cut, stamped, or molded into specific shapes. Moreover, a substantial number of counterweights used today do not serve any structural purpose. In most instances, they are only a ballast to provide weight in the proper location so that the object functions as intended.
File cabinets used in offices also typically have a large mass in the back of the cabinet, behind the lower drawer boxes, to keep the cabinet from tipping over when a heavy drawer is opened. The size of the mass is determined by the anticipated weight of the contents in the filing cabinet drawers, how far each drawer is allowed to open, and whether or not other drawers are allowed to open at the same time.
In the past, different types of counterweights have been used to help stabilize file cabinets. The different types of materials are selected based upon the volume of the space available as well as the density of the material. The most often selected material has been steel plate because it does not require a substantial volume, can be easily stamped to the desired shape or area, and because of its weight. However, because of the ever increasing cost of steel, alternative sources of raw material for making counterweights must be explored.
Most counterweights used in file cabinets are not structural parts, and only function as mass. Therefore, material properties such as strength are not an issue. The disadvantage of current counter weight systems is that manufacturers are using original raw materials to manufacture such weights. Iron and steel are being worked in forges to produce molded objects or plate steel that is cut or otherwise stamped to the desired shape, let alone worked again and again to produce a desired shape. It is certainly a purpose of this invention to provide a novel and unique method for manufacturing counterweights at a lower unit cost than currently available, while at the same time reducing the demand on raw materials.

SUMMARY OF THE INVENTION

According to one form of the invention, a method is described for forming an object from scrap metal, comprising the steps of obtaining scrap metal for a source; organizing the scrap metal into predetermined classes based upon at least one criterion; forming a charge from at least one class of scrap metal; and compressing the charge into a predetermined shape. The method may be modified by of enclosing the charge within a polymeric container that may act both as a lubricant during the compression stage, and as a binder as a result of the polymer flowing in between at least some of the grains of scrap metal and substantially surrounding the finished form. Additional forms of the invention may include performing processes prior to the forming stage including the removal of contaminants and sorting of the scrap metal based upon one of size, type, and grade.
According to another form of the invention, a method is provided for making a non-structural work piece from scrap metal as a raw material, including sorting the raw material into at least one class based upon at least one criterion; enclosing a predetermined amount of the raw material in a container to form a charge; and pressing the charge into a predetermined shape. To aid in the forming of the shape, the invention also contemplates using the container to act as a lubricant and as a binding agent when the pressing step has been substantially completed.
In yet another form of the invention, it is contemplated that a suitable forming method is to compress the charge into one of a briquette or forming the charge by way of cold forging.
In another form of the invention a method for making metallic work pieces is disclosed, comprising providing scrap metal as a raw material; enclosing a predetermined amount of the raw material in a polymeric bag to form a charge; and compressing the charge under a predetermined amount of pressure to form the work piece.
The work piece resulting from the method is comprised of a plurality of grains of scrap metal compressed into a substantially cohesive form; and a polymeric material covering a substantial portion of the substantially cohesive form and at least a portion of said plurality of grains of scrap metal.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The sole drawing FIGURE in the application constitutes a flow diagram illustrating the basic steps of the invention

DETAILED DESCRIPTION OF THE DIFFERENT EMBODIMENTS

For purposes of the following description, the terms “upper,” “lower,” “left,” “rear,” “front,” “vertical,” “horizontal” and derivatives of such terms shall relate to the invention as oriented on a particular page. It is to be understood that the invention may assume various alternative orientations and configuration, except where expressly specified, devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the invention. Specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting unless expressly stated otherwise.
The material for producing metallic work pieces such as counterweights and like objects is metal scrap often disposed of by other manufacturers as a waste by-product. The invention need not be specific to any particular form of scrap, although it is anticipated that the grade of scrap may become an important issue in certain manufacturing methods. For the purposes of this invention, the grade and type of metal scrap will not be considered a limiting factor. However, the following description will be given with respect to metal waste or scrap produced in a typical milling or turning operation in a machine shop.
In one embodiment of the invention, a work piece such as a counterweight may be manufactured by obtaining scrap metal from one of a number of sources. The source may be internal to the operation of the business or the scrap may be purchased from any one or more vendors who recycle such materials. The gathering of the scrap metal is represented as box 12 of the flow chart 10 shown in FIG. 1. Regardless of how the scrap metal is gathered or obtained, it may be preferred to sort the scrap based upon one or more predetermined characteristics. This step is represented by step 14 in FIG. 1. One such anticipated characteristic may be based upon composition—that is ferrous versus non-ferrous metals. Another basis for classification may include size, purity, shape, density, etc. that can be determined using any one of a number of sorting methods and techniques. In addition, it may be desired to clean the scrap metal to remove any contaminants including, but not limited to, oils or other volatiles that could later seep from the completed work piece or present a hazard to workers and the environment during the manufacturing process. The sorting and cleaning processes have been combined for the purposes of representing the steps in FIG. 1.
Once the scrap metal has been processed as minimally or thoroughly as desired, a predetermined amount of the scrap metal is metered to form what will be referred to herein as a “charge.” See Step 16 in FIG. 1. The term “charge” as used herein is to refer to a predetermined volume or amount of the scrap metal to be used in any subsequent process. The charge may be formed based upon the weight of the material. Alternatively a predetermined volume or cavity may be filled such as bucket of a loader or the like.
Once the charge of scrap metal is established, the forming process takes place. The particular type of forming method may vary depending in large part upon what, if any, subsequent processes will occur. For example, as represented by Step 18 in FIG. 1, it is contemplated that a user may simply perform a single step forging method where the charge is compacted and shaped at the same time. This type of process may be used to produce a shape having a lesser density than by other methods, but can be performed quickly with some degree of certainty that the shape will be retained for at least a short period of time. Alternatively a more complex multistage compression technique may be used to compact the scrap metal into a more dense and cohesive form. It is envisioned that a forming technique may be used to introduce sufficient pressure to possibly cause some of the grains or granules of the scrap to fuse or merge together. At the very least, it is envisioned that the technique used to compress the scrap metal will cause the different grain or piece of metal scrap to adhere to one another in a cohesive fashion.
In an alternative form of the invention, metal shavings are routinely collected by salvage vendors who either pay for the material or charge a fee for removal depending on the grade of the material collected. The vendor may then employ the invention or alternatively sell the scrap metal shavings to another who would employ the process. In either event, one type or category of machinery that may be used in the invention is generally referred to as a “briquetting” machine. The recycler would dispense a predetermined volume of steel shavings into the “briquetting” machine which is already configured to accommodate the amount of the shavings used. See Step 20 of FIG. 1. The briquetting machine is a commercially available device that compacts scrap material such as the steel shavings or millings into a brick or cylinder. Although the common form of the output from the briquetting machine may be a cylinder of predetermined length and diameter, it is also contemplated that these types of machines may be easily altered or modified to produce output of different shapes. Machine shops often purchase briquetting machines to compact their scrap into a more valuable form for sale to salvagers.
According to one specific form of the invention, the output from briquetting machines can be used as a low cost raw material for the production of parts. See Step 20 of the flow diagram 10. If the requirements for the part are simple, the briquette may require no further processing and used as is. If the part form is more complex, the briquette form may be placed into a die equipped with a cavity matching the desired shape of the final part and cold forged. The forging process increases the density to the part and allows custom features to be added.
The material for producing one form of a counterweight made according to the invention is shredded steel scrap such as produced in a typical milling or turning operation in a machine shop. The shavings can be routinely collected by salvage vendors who either pay for the material or charge a fee for removal depending on the grade of the material collected. This is the raw material feedstock according to one embodiment of the invention.
After collecting the scrap metal, it is envisioned that the material would be cleaned to remove any undesirable volatiles or environmentally undesirable chemicals. To aid in either of the manufacturing or cleaning process, it is also contemplated that the scrap metal may be shredded to produce a more uniform mix of chip sizes. Not only does the shredding increase the surface area of any cleaning, it also may be used to reduce the size variation of the material and make handling of the raw material easier.
After shredding the material and cleaning process, the raw material scrap may be fed on to the compaction process. The compaction process would most preferably compress the chips of scrap metal together into an interlocking mass. In certain instances, the pressure may be applied by rolling the material between platens or rollers designed to compact the chips into a dense sheet. This process could be similar to cold-rolling steel but with the aim of re-compacting the material and increasing the density. After rolling, the part may be die cut or sheared into smaller, more uniform and usable lengths and processed.
According to another form of the invention, the scrap metal is delivered to the manufacturer, either from a vendor or from an in-house source. Regardless of the source of the scrap metal, the grain size of the scrap may be made more uniform by passing the scrap through a grinding or shredding process. In addition the form of the grains or granules may be modified. For example, it may be desired to work with grains or granules that are more plate like in shape. This plate-like appearance may be obtained by passing the scrap through a ball mill or similar percussion device.
With the scrap in a more uniform grain size, the material lends itself to more conventional handling using conventional conveyor belts or material handling processes. Using these types of translative methods, the scrap metal may be passed through a number of processes to remove any contaminants, undesirable coatings, or it may be separated based upon density. This way, more refining of the scrap metal may be achieved.
Once the metal is passed through the refining process and sorted based upon one or more of those characteristics, the scrap metal may be dispensed in predetermined amounts into polymeric bags or containers. The containers not only would serve to constrain the smaller grains of scrap metal to an enclosed container, but the size of the container may also serve an additional function. As briefly mentioned, above the scrap metal is measured into charges suitable to provide the proper material for a given process. In this embodiment, not only do the polymeric containers contain the proper amount of a charge, but the container itself may act as a lubricant during the compression or compaction process, requiring relatively little heat to cause the container to change from a solid to a molten state. As the compaction process continues, the polymeric material housing the scrap is melted in a manner to form a protective coating over the exposed surfaces of the newly formed object or work piece. In certain instances, the polymeric material may actually form a protective envelope over the work piece to reduce the exposure to oxidizing processes, contact with sharp points and edges, and overall a safer work piece. In either event, the change in state of the container from a solid to a molten or plastic state will act to bind some of the grains/granules together and provide a more cohesive form. Following the forming process, the finished form is ready to be used in the desired application as ballast or counterweight or other function.
The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention.

Claims

1. A method for forming an object from scrap metal, comprising the steps of:

Obtaining scrap metal;

organizing the scrap metal into predetermined classes based upon at least one characteristic of the scrap metal;

forming a charge from at least one of said predetermined classes of scrap metal; and

compressing said charge into a predetermined shape.

2. The method as defined in claim 1, further comprising the step of enclosing said charge within a polymeric container.

3. The method as defined in claim 1, further comprising the step of removing contaminants from the scrap metal prior to the step of forming the charge.

4. The method as defined in claim 1, further comprising lubricating the charge during the step of compressing.

5. The method as defined in claim 1, wherein the step of obtaining scrap metal includes at least one of acquiring the scrap metal from a third party and gathering the scrap metal as a result of a bi-product internally.

6. The method as defined in claim 1, wherein organizing the scrap based upon at least one characteristic comprises sorting the scrap metal based upon one of size, type, and grade.

7. The method as defined in claim 1, wherein the step of forming a charge includes defining a predetermined amount of the scrap metal using a predetermined metric.

8. The method as defined in claim 1, wherein the step of compressing the charge comprises subjecting the charge to a predetermined amount of pressure and heat to cause the scrap metal to remain in a cohesive form.

9. The method as defined in claim 2, wherein the step of compressing causes the container to act as a binder.

10. The method as defined in claim 2, wherein the step of compressing includes flowing at least a portion of the container around at least a portion of the scrap metal.

11. The method as defined in claim 2, wherein the step of compressing comprises melting at least a portion of the container into a least a portion of the scrap metal.

12. The method as defined in claim 3, wherein the step of removing contaminants includes at least one of cleaning the scrap metal and sorting the scrap metal based upon meal type.

13. The method as defined in claim 4, wherein the step of lubricating comprises the step of placing the scrap metal within a polymer.

14. A method for making a non-structural work piece, comprising the steps of:

providing scrap metal as a raw material;

sorting the raw material into at least one class based upon at least one criterion;

enclosing a predetermined amount of the raw material in a container to form a charge; and

pressing the charge into a predetermined shape.

15. The method as defined in claim 14, further comprising lubricating said charge during the step of pressing.

16. The method as defined in claim 14, further comprising providing a polymer to at least partially surround the raw material during the step of compressing.

17. The method as defined in claim 14, wherein the step of compressing including producing a briquette.

18. The method as defined in claim 14, wherein the step of compressing includes the step of cold forging.

19. A method for making metallic work pieces, comprising the steps of:

providing scrap metal as a raw material;

enclosing a predetermined amount of the raw material in a polymeric bag to form a charge; and

compressing each charge under a predetermined amount of pressure into a predetermined work piece.

20. A work piece, comprising:

a plurality of grains of scrap metal compressed into a substantially cohesive form; and

a polymeric material covering a substantial portion of said cohesive form and encasing at least a portion of said plurality of grains of scrap metal.