EP0110970A1

EP0110970A1 - Alternating-current attracting electromagnet

Info

Publication number: EP0110970A1
Application number: EP19830902173
Authority: EP
Inventors: Richard Mcclees
Original assignee: McCLEES INDUSTRIES Inc
Current assignee: McCLEES INDUSTRIES Inc
Priority date: 1982-05-26
Filing date: 1983-05-26
Publication date: 1984-06-20
Also published as: WO1983004340A1

Abstract

L'invention concerne un électro-aimant d'attraction. Les électro-aimants connus de l'art antérieur sont complexes et difficile à fabriquer. La présente invention s'emploie en particulier à faciliter un assemblage simple et économique de l'électro-aimant. L'éléctro-aimant comprend une tige allongée en fer doux (14) ayant un disque annulaire en cuivre ou argent (16) fixé à une extrémité de la tige (14), et un disque en bois ou fibre (18) fixé à l'autre extrémité de la tige (14). Une feuille d'étain flexible (24) forme une coquille extérieure (12) autour des périphéries des disques (16 et 18) pour créer un corps ayant l'aspect d'un cylindre. Un fil conducteur formant des couches (28, 34) est enroulé autour de la surface extérieure de la coquille (12) et une source de courant alternatif est appliquée aux couches de fils. L'électro-aimant peut fonctionner pour attirer tant des matériaux magnétiques que des matériaux non-magnétiques.The invention relates to an attraction electromagnet. The electromagnets known from the prior art are complex and difficult to manufacture. The present invention is used in particular to facilitate a simple and economical assembly of the electromagnet. The electromagnet includes an elongated soft iron rod (14) having an annular copper or silver disc (16) attached to one end of the rod (14), and a wooden or fiber disc (18) attached to the 'other end of the rod (14). A flexible tin foil (24) forms an outer shell (12) around the peripheries of the discs (16 and 18) to create a body having the appearance of a cylinder. A layered lead wire (28, 34) is wrapped around the outer surface of the shell (12) and an alternating current source is applied to the wire layers. The electromagnet can operate to attract both magnetic and non-magnetic materials.

Description

-1- Description

ALTERNATING-CURRENT ^'ATTRACTING ELECTROMAGNET

Technical Field

The present invention relates to new and useful improvements in electromagnets and more particularly pertains to a new and improved electromagnet construction which is operable to attract non-magnetic conducting materials as well as magnetic materials . Background Art

The use of electromagnets which will attract both magnetic and non-magnetic materials is known in the art. In this respect, reference is made to a September, 1962 issue of Popular Electronics magazine and specifically to an article at page 48 thereof entitled "The Master Magnet". The article discusses the construction of an alternating current electromagnet which will pick up pieces of copper, aluminum, silver, gold and other non- errous metals. However, the construction of the magnet described is substantially complex and difficult to build inasmuch as the same requires the use of a specially assembled frame and a -2- plurality of laminations taken from or constructed in the manner of a transformer. Additionally, the construction of the magnet requires the forming and installation of a plurality of copper washers which are specifically dimensioned to fill the space between ends of the inner and outer magnet cores. As such, the construction of the magnet is quite complex and is uneconomical to fabricate.

Also of interest with respect to the construction of electromagnets operable to attract both ferrous and non-ferrous materials is U. S. Patent 2,400,869, which issued to Lovell on May 28, 1946, wherein such an electromagnet is described. While various modified embodiments of the electromagnet are discussed in the Lovell patent, the construction of the disclosed embodiments are substantially different from the present invention, as well as being inefficient and uneconomical to manufacture in comparison thereto.

Lastly of interest is U. S. Patent 3,054,026, also issuing to Lovell on September 11, 1962, with this patent being directed to the use of an electromagnet for attracting non-ferrous materials

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^£ ι\'A in a surgical capacity. The construction of the electromagnet differs substantially from the present invention and accordingly, no further discussion thereof is necessitated. As such, it can be appreciated that there exists a continuing need in the electromagnet technology relating to the attraction of non- ferrous attracting electromagnets for new and improved non-ferrous attracting electromagnets which are of a simple and economical construction and which possess the capacity for easy maintenance, and efficient and reliable operation. In this respect, the present invention substantially fulfills this need. Disclosure of Invention

The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved electromagnet for attracting both ferrous and non-ferrous materials which has all the advantages of the prior art electromagnets and none of the disadvantages. To attain this, the present invention is particularly designed to facilitate a s imple and economical assembly. More specif ically , the present invention includes the use of an elongated soft iron rod having an annularly-shaped copper or silver disk attached to one end thereof and a second annularly-shaped plastic, wood or fiber disk attached to the other end thereof. In this respect, the two disks are provided with centrally-positioned apertures into which the ends of the soft iron rod may be frictionally inserted, and a sheet of flexible tin may then be wrapped about the peripheries of the disks along the axial length of the soft iron rod. The tin is of a continuous construction so as to extend between the disks and thus create the appearance of a cylinder wherein the soft iron rod is substantially concealed. The tin may be held in position through the use of electrical tape or some other well known binding means, and alternating layers of conductive wire and tape may then be wrapped about the outer surface of the encircling tin. A source of alternating current applied to the wrapped wire completes the construction of the invention.

With respect to the theory of operation of the invention, it should be noted that the scientific community still cannot entirely relate the effects of magnetism with other scientific knowledge, so as to clarify its basic nature. In this regard, it's easy to find out what magnets will do, yet it is far from obvious just exactly why magnetism exerts its force and why this force seems to exist at all known parts of the universe. Magnetism is like gravity, i. e. , we have an excellent understanding of its operation as a physical phenomenon, but while it is very useful, there is a great deal yet to be learned about its operational theory.

Based upon this lack of understanding of magnetism then, we at least recognize the fact that iron is a very strong magnetic material and the theory of why it is such has to do with its 26 electrons. These electrons are arranged in four shells, with there being two electrons in the first shell — one spinning in one direction and one spinning in an opposed direction. There are eight electrons in the second shell, with four spinning in one direction and four in the opposite direction, and there are 14 electrons in the third shell, with nine spinning in one direction and -6- five in the opposite direction. It should be noted that in the third shell, four electrons are spinning unopposed, i. e. , there are no matching oppositely spinning electrons, and the final two electrons are located in the fourth shell and move just as those in the first shell. Various physicists have shown that in addition to moving about the nucleus of an atom, an electron also spins on its axis and because of this spin, it is surmised that a magnetic field is generated. For this magnetic field to be strongly magnetically attracting, the assumption is that there must be more electrons spinning in one direction than in an opposite direction. As such, the iron with four unopposed electrons in the third shell is strongly magnetic. Cobalt, nickel and gadolinium are also strongly magnetic for the same reason as iron. Additionally, there are alloys which are strongly magnetic for the same reasons and as such, we surmise that the electron is the smallest known magnet.

It follows, therefore, that the magnetic properties of materials relate directly to the alignment of the magnetic fields of their

"~: T\oy electrons. More particularly, magnetic materials have groups of atoms whose magnetic fields are more or less permanently lined up. These groups of atoms are commonly referred to as magnetic domains. Each domain is made up of thousands of atoms clustered together with these atoms being arranged in such a manner that the domain acts as a small magnet with north and south seeking poles. In this respect, in an unmagnetized piece of magnetic material, the magnetic domains are arranged in a haphazard manner and as the magnetic material becomes more and more magnetized, more and more of the magnetic domains are aligned. Such alignment results in the north seeking poles all being directed in one direction, with the south seeking poles being similarly aligned in the opposite direction. The magnetic material is fully magnetized when all of these domains are aligned. With this understanding of magnetic domains then, it can be seen that the arrangements of domains within non-magnetic materials is such that they cannot easily be arranged to effect a desired alignment. Therefore, some means must be found to -8- effect an alignment of these atoms within the nonmagnetic materials if the same are to become magnetic. Inasmuch as the present invention causes nonmagnetic materials to become magnetic,

5 the assumption is that the invention operates to effect an alignment of the magnetic domains within the materials.

Continuing with the theory of the present invention, reference is again made to the

10 a bo ve -mentioned article "The Master Magnet" wherein a discussion of the magnetic theory associated therewith is provided. Specifically, the article notes that an electromagnet's windings are powered by alternating current so as to create

15 an alternately increasing and decreasing magnetic field in the center core. When this varying field passes through a set of copper washers fastened to an end of the core, a large current is induced so that the washers essentially act as a transformer

20 secondary. A strong varying magnetic field is set up in the washers as a result of the induced current, and the direction of the field is such that the washers and core repel each other. If the washers were not securely anchored to the core or some other retaining structure, they would spring out of their mounting as soon as the current was turned on. By the same token, the varying field in the washers will induce, in turn, a large current in any metal object (ferrous or not) brought near them, with the current then of course acting to set up a magnetic field in the approaching object. Further, the direction of the field will always be such that a part of the object in contact with the outside face of the set of washers will have the opposite magnetic polarity from that face and thus, the object will be attracted thereto. Brief Description of Drawings Figure 1 is a perspective view of the electromagnet forming the present invention. Figure 2 is a transverse cross-sectional view of the present invention taken along the line 2-2 in Figure 1. Figure 3 is a longitudinal cross-sectional view taken along the line 3-3 in Figure 2. Best Mode for Carrying Out the Invention

With reference now to the drawings and in particular to Figure 1 thereof, a new and improved electromagnet for attracting both ferrous and non-ferrous materials embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described. In this respect, it can be seen that the elec romagn t 10 may normally be of a cylindrical construction to include an outer shell portion 12 circumf erentially positioned about a soft iron rod core 14, while being attached thereto and spaced therefrom by a pair of annular disks 16, 18, onl -one of which is illustrated in Figure 1.

Viewing Figures 2 and 3 concurrently with Figure 1, a more thorough understanding of the construction of the present invention can be ascertained. In this connection, the annularly-shaped disk 16 is formed of either copper or silver. By the same token, disk 18 should be formed from either plastic, wood or fiber materials, with the respective disks 16, 18 being then securely attached to opposed ends of the aforementioned soft iron rod core 14. This securement of the disks 16, 18 can be accomplished by drilling respective centrally-posi ioned apertures 20, 22 in the disks, such apertures being constructed approximately one-thousandth of an inch smaller than the outside diameter of the soft iron rod 14 to thereby accomplish a desired frictional fit.

To undertake the construction of the outer shell 12 of the electromagnet 10, a sheet of tin 24 may be wrapped about the outer peripheries of the disks 16, 18, with such tin being of a continuous construction whereby the same extends between the disks along the longitudinal length of the soft iron rod core 14. Upon being wrapped tightly about the disks 16, 18, a layer of electrical tape 26, such as Scotch brand, may be used to securely hold the tin 24 in position about the disks. In this regard, the tape can be utilized to completely cover the tin 24, thereby to insure a tight and secure connection between the tin and the circumferential portions of the disks 16, 18. Using varnished motor rewind wire, a first layer 28 thereof may be wound about the tin shell 24 along the complete axial length thereof as measured from the plastic, wood or fiber disk 18 to the copper or silver disk 16. An extending lead 30 of this initial layer of wire 28 should be left projecting outwardly from the tin shell 24 so as to form the first half of an eventual electrical connection to a source of alternating current.

Once the first layer 28 of electrical wire has been smoothly and symmetrically wound about the tin shell 24 along the axial length thereof, a second layer of electrical insulating tape 32 may be utilized to retain the wire in its tightly wrapped position, and then a second layer 34 of the wire may be wound in the opposite direction over the tin shell 24. This second layer 34 of wire will also be symmetrically and tightly wrapped along the axial length of the tin shell 24, as measured from the disk 16 to the disk 18, with this second layer then being tightly and securely retained in position by a third layer of insulating tape 36. While the preferred embodiment of the present invention as illustrated in Figures 1-3 only discloses two layers 28, 34 of electric motor rewind wire, it is to be understood that any such number of layers of electrical wire could be -13- employed without departing from the scope and intent of the invention or without departing from the function thereof. In actual practice, the preferred embodiment would normally employ the use of five layers of electrical wire. As can be seen with further reference to Figure 3 of the drawings, upon the completion of the winding of the final layer 34 of electrical wire, such wire may be left extending outwardly to form lead 38, whereby the leads 30, 38 may then be electrically interconnected with the aforementioned source of alternating current, thereby to provide the power circuit of the electromagnet 10.

In operation, the electromagnet 10 may be connected to a source of alternating current, as af orediscussed, through the use of the electrical connection leads 30, 38, and with such driving electrical power being supplied thereto, the electromagnet 10 assumes its operable capacity. In this regard, the end of the electromagnet 10 formed by the copper or silver disk 16 can then be utilized to attract various ferrous and non-ferrous materials. Additionally, it has been found that the capacity of the electromagnet 10 to attract various non-ferrous materials can be substantially varied by controlling the magnitude of the voltage supplied thereto. In this respect, the supplying of a first voltage to the electromagnet 10 may facilitate its attraction to some specific element such as gold, while causing the same to substantially ignore other metallic substances, while a slightly varied voltage may result in the electromagnet attracting aluminum, as opposed to gold and other metals. In effect, the present invention can be operated at a certain voltage to effectively attract one specific non-magnetic material that might be mixed among many different non-magnetic materials, and then by changing the voltage to a differnt setting, a different non-magnetic material may be withdrawn from such a mixture. Through appropriate voltage control, the domains of the electromagnet 10 can be appropriately aligned to give either an attraction or pulling force or alternatively a repulsion or pushing force. Similarly, the magnetic field strength of the magnet can be controlled by utilizing a higher frequency alternating current than the normal 110 volt, 60 -15- cycle commercially available supply. By experiment, it has been shown that the attraction or repulsion of any non-magnetic material by the electromagnet 10 is proportional to numerous variables, examples of which are wire size, wire length, wire type, core size, core type, number of windings, size of windings, etc.

As can be appreciated then, the present invention offers unlimited opportunities for scientific exploration and possesses an enormous number of potential uses which could be beneficial to mankind. For example, it is well known that the oceans of the world are essentially enormous ore deposits, with it being predicted that there is a million dollars' worth of gold alone dissolved in every cubic mile of sea water. Through a- proper use of the present invention, it is conceivable that this gold could be recovered inexpensi ely by simply moving the sea water past a bank of the electromagnets 10. By the same token, various other minerals could be removed from sea water by choosing the appropriate voltage frequency settings. Another potential use of the present invention, of course, would be in the metal sorting industry where it is desired to remove certain metals intermixed with other metals. Also the present invention might be utilized as a cleaner in the food industry, i. e. , to remove certain metallic materials from food, while there is also potential in non-moving part propulsion systems for vehicles of the future.

Other potential uses of the present invention include the holding and clamping of non-ferrous materials .in work stations, such as brass cartridges and the like, the testing of multi -material welds, metal forming by magnetic tension, the lifting of non-ferrous metals in oil field wells and the like, the retrieval of spilled non-ferrous metals, such as aluminum nails, on highways , and as a stud finding device. Additionally, the present invention could be utilized in the capacity of particular material detection and/or holding, or as a magnetic broom, as an electromagnetic brake whereby certain non-ferrous metals could be employed to facilitate better heat dissipation, as magnetic couplings or switches, as magnetic shock absorbers, and for physiotherapy applications in the medical field. Of course, the present invention could also be utilized for metal identification, anti-friction bearings, magnetic suspension in vehicles, toys and games, magnetic locks, magnetic alignment or centering or for magnetic closures. In effect, it can be seen that the applications of the invention are essentially endless and it is expected that all such applications fall within the scope and intent of the present invention. With respect to the above description then, it should be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, shape, form, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention

- XJKtA ^*' G__?I_ ⁷cT;.;_.τlO to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted, falling within the scope of the invention.

Claims

1. A new and improved electromagnet for operably attracting both magnetic and non-magnetic materials comprising: core means; disk means operably connected to said core means; shell means operably attached to said disk means; and conduction means selectively positioned over said shell means, said conduction means being operable to receive a supply of alternating current to power said electromagnet.

2. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 1, wherein said disk means includes at least a first .disk constructed of electrically conductive material and a second disk constructed of an electrically insulative material.

3. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 2, wherein said first disk means is constructed from a material consisting of one of silver and copper.

4. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 2, wherein said second disk is constructed from a material consisting of one of fiber, wood and plastic.

5. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 2, wherein said shell means is of a tin construction operably connected between said first and second disks.

6. The new and improved electromagnet for 10 operably attracting both magnetic and non-magnetic materials as defined in claim 2, wherein said conduction means includes the use of electrically conductive wire operably wrapped about said shell means.

157. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 6, wherein- said electrically conductive wire is of a continuous construction and is wrapped in multiple layers

20 over said shell means, said multiple layers being appropriately insulated from one another.

8. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 7, wherein electrical tape is used as a means of insulating said multiple layers of electrically conducting wire wrapped about said shell means.

9. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 2, wherein said core means is constructed of a magnetic material.

10. The new and improved electromagnet for operably attracting both magnetic and non-magnetic materials as defined in claim 1, wherein said core means is of an elongated rod construction, said core means being constructed of a soft iron material, and further wherein said disk means includes first and second disks frictionally attached to opposed ends of said rod, said first disk being constructed from a material consisting of one of silver and copper, and said second disk being constructed from a material consisting of one of plastic, fiber and wood, said shell means being positioned between said first and second disk and extending about peripheries thereof, said shell means being constructed from tin, with said conduction means being operably wrapped about said shell means, said conduction means consisting of a continuous length of electrically-conductive wire wrapped in multiple layers about said shell means, said multiple layers being appropriately insulated from one another by insulation means comprising electrical insulation tape, with opposed ends of said electrically-conductive wire being then directable to a variable alternating current voltage source, whereby current may be supplied to said electromagnet to effect a desired operation thereof.