| United States Patent | 3,651,439 |
| Ioffe , et al. | March 21, 1972 |
METHOD OF ORIENTING ELECTRICALLY CONDUCTIVE BODIES, PREFERABLY
NON-MAGNETIC ONES, IN A MAGNETIC FIELD AND APPARATUS FOR PERFORMING SAME
Abstract
There are disclosed a method of orienting electrically conductive bodies, preferably, made of non-magnetic materials, in a magnetic field and an apparatus for performing this method, according to which a body is oriented by the action thereupon of a non-uniform magnetic field created by an alternating electric current, by means of a electromagnet, the orientation operation being determined by the features of the body, giving different electric conductivity to the portions of this body, disposed at the opposite sides thereof. Such method can be used for orienting various articles and workpieces having hidden internal characteristic features, such as flat bi-metal workpieces of non-magnetic electrically conductive articles having asymmetrical opposite sides, or else articles enclosed within an external casing, so that their characteristic structural or technological features are hidden from view.
| Inventors: | Ioffe; Benyamin Alexandrovich (Riga, SU), Mikelson; Artur Eduardovich (POSELOK Salapils Rizhsky raion, SU), Makhlin; Aron Judovich (Moscow, SU), Lapidus; Mikhail Khaimovich (Riga, SU), Salnikov; Jury Nikolaevich (Gorky, SU), Kazhe; Alexandr Zhanovich (Riga, SU), Trushelis; Ivan Avgustovich (Riga, SU) |
| Appl. No.: | 04/885,193 |
| Filed: | December 15, 1969 |
| Dec 25, 1968 [SU] | 1289058 | |||
| Current U.S. Class: | 335/219 ; 198/381; 29/744; 335/297 |
| Current International Class: | B07C 5/00 (20060101); B07C 5/02 (20060101); B65G 47/24 (20060101); B65G 47/256 (20060101); H01f 001/100 () |
| Field of Search: | 209/215 214/152 198/41 335/284,299,250,229,234 |
| 3054026 | September 1962 | Lovell |
| 181,481 | Oct., 1964 | SU | |||
Assistant Examiner: Bell; F. E.
What is claimed is:
1. A method of orienting an electrically conductive body, preferably, non-magnetic, in a magnetic field, said method comprising dropping through an orientation zone bodies having opposite sides with different electroconductivities therein, orienting each said body in said zone by the action thereupon of a non-uniform magnetic field created by an alternating electric current, and regulating the frequency of said alternating electric current to provide for a predetermined depth of penetration of the flux of said magnetic field into said body, said depth not exceeding the corresponding linear dimension of said body.
2. An apparatus for orienting an electrically conductive body, preferably, non-magnetic, in a magnetic field, said apparatus comprising: an electromagnet adapted to be connected to an alternating current supply source; said electromagnet including at least one pair of pole pieces defining therebetween an orientation zone, one of said poles pieces being substantially wedge-shaped and having a pointed edge facing said orientation zone; means for depositing the body for free fall through said orientation zone; and means for preventing rotation of said body during free fall about an axis parallel to said pointed edge of said substantially wedge-shaped pole piece.
3. An apparatus as claimed in claim 2, wherein said means for preventing rotation of said body about an axis parallel to said pointed edge of said substantially wedge-shaped pole piece comprises a second electromagnet adapted to be supplied with an alternating electric current of a frequency different from that of said alternating current supply to said first-mentioned electromagnet, said second electromagnet having at least one pair of substantially flatfaced pole pieces facing each other and said orientation zone.
The present invention relates to a method of orienting electrically conductive bodies, preferably, made of nonmagnetic materials, in a magnetic field, and to apparatus for performing this method, which apparatus performs orientation of such bodies into a desired position of their side surfaces or planes having different values of electric conductivity.
A method of orienting electrically conductive bodies in a magnetic field is known, according to which a body is oriented, as a result of interaction of a magnetic field produced by a permanent magnet with alternating electric currents induced in the body being oriented.
However, this known method does not provide for adequately accurate orientation of successive bodies, and, besides, it cannot be used for orienting flat bodies into a desired position of their opposite flat sides having different electric conductivity.
It is an object of the present invention to overcome these disadvantages.
The present invention contemplates a method orienting electrically conductive bodies in a magnetic field and of an apparatus for performing such method, which will provide for orienting a body into a desired spacial position of one of its planar surfaces, the body being characterized either by a structural asymmetry or by its being made of different materials, whereby different portions of this body have different values of electrical conductivity.
This is attained in the herein disclosed method of orienting electrically conductive bodies in a magnetic field, in which, in accordance with the present invention, a body is oriented by the action thereupon of a non-uniform magnetic field generated by an alternating electric current, the orientation being determined by the features of said body yielding different electric conductivity of the portions thereof disposed adjacent to the opposite sides of said body, the frequency of said alternating electric current being selected to provide a predetermined depth of penetration of the magnetic flux of said field into said body, said depth not exceeding the respective linear dimension of said body.
An apparatus for performing said method comprises, in accordance with the present invention, an electromagnet adapted to be supplied with an alternating electric current, one of the pole pieces of said electromagnet being shaped as a wedge having its pointed edge facing the orientation zone, and means preventing rotation of said body about an axis parallel to said pointed edge of said wedge-shaped pole piece.
In a preferred embodiment of the present invention, said means for preventing rotation of said body includes a second electromagnet adapted to be supplied with alternating electric current, the frequency of said last-mentioned alternating current supply being different from the frequency of said first-mentioned alternating electric current supply to said first electromagnet, the pole pieces of said second electromagnet having substantially flat faces facing each other and said orientation zone.
A method of orienting electrically conductive bodies in a magnetic field, embodying the present invention, and the apparatus performing such method have been found to attain the aims and objects, as set hereinabove, and also to be capable of orienting various articles and workpieces by their internal characteristic features, for example, flat bi-metal articles, or else non-magnetic electrically conductive parts having asymmetrical side planes and encased within a solid plastic housing, hiding from view the structural features and the internal asymmetry of these parts.
The present invention will be better understood from the following detailed description of an embodiment thereof, with due reference being made to the accompanying drawings, wherein:
FIG. 1 illustrates schematically in perspective view an operation of indexing asymmetrical flat bodies by the different electric conductivity of their opposite sides, in accordance with the present invention;
FIG. 2 shows several samples of articles which may be indexed by a method embodying the invention;
FIG. 3 shows schematically in perspective view an apparatus performing a method embodying the invention; and
FIG. 4 shows schematically an arrangement of chutes for supplying successive bodies into the indexing zone and delivering said bodies therefrom, in the apparatus shown in FIG. 3.
Referring now in particular to the appended drawings, the main aspects of a method, embodying the invention, are, as follows.
A body to be oriented, e.g. an article 1 (FIG. 1) is forwarded along a chute 2, from the open end of which it falls by gravity into the space between the respective pole pieces of electromagnets 3 and 4 of which the respective windings are supplied with alternating current, the frequency of the alternating current supplied, respectively, to the windings 5 and 6 of the electromagnets 3 and 4 being different.
The electromagnet 3 produces a magnetic field whose induction decreases toward the body being oriented, whereby the latter, as it falls in the magnetic field, is repelled by this electromagnet. The value of the electromotive force produced by the interaction of the magnetic field created by the electric current induced in the side portion of the article 1, facing the electromagnet 3, with the external alternating magnetic field is in direct proportion to the electrical conductivity of the last-mentioned portion (presuming that the other parameters, such as the voltage of the field, its frequency and the rate of the descent of the article 1 are of pre-determined constant respective values).
Thus, it has been found essential to adjust the frequency of the alternating current supply to the electromagnet 3 to a value corresponding to a desired depth of penetration of the magnetic flux of this electromagnet into the article 3, this depth of penetration not exceeding, however, the corresponding linear dimension of the article being oriented in the direction of the magnetic flux, i.e., in the direction toward the source of this magnetic flux. For example, if the side of the article 1, facing the pole piece of the electromagnet 3, has grooves or indentations of a depth about 1.5 mm., it has been found desirable for the frequency to be about 1,000 cycles per second; should the depth of these grooves or indentations be about 0.5 mm., the corresponding frequency is about 3,500 c.p.s.
In the case when the opposite sides of the article 1 are of different configurations, or else they have different structural features, e.g. one of the sides is grooved, knurled, slotted, etc., and also when the opposite sides of the article are made of materials with different values of electrical conductivity, the path of the free fall of such article in the magnetic field of the electromagnet 3 would be different, depending on which side of the article faces the electromagnet 3, whereby at the end of that fall the article will arrive in a respective one of the two delivery chutes 7. The last-described principle can be successfully applied either for assorting successive article according to their structural features (when different ones of the successive articles have different structural features of their side portions facing the electromagnet, or else when similar articles are supplied, with their different side portions facing the electromagnet) or for rejecting defective articles in a likewise manner, which can be highly useful for a broad variety of automatically performed processing and assembling operations.
In order to prevent rotation of the main plane of a flat-shaped article (under the expression "flat-shaped" here is understood an article having a thickness substantially smaller than the other two dimensions thereof, and the main plane of such article is the one perpendicular to its thickness) relative to the electromagnet 3, as the article falls through the orientation zone, a desired position of this plane of the article is retained by the action of a magnetic field produced by a second electromagnet 4, of which the vector of the magnetic flux is directed along the said plane in the desired position thereof. Thus, the article 1 would not only fall with the desired position of its main plane being positively retained, but would be also rotated into this desired position, in case it is supplied into the orientation zone in a different angular position.
Therefore, as the article 1 falls through the space defined by the pole pieces of the two electromagnets, it is oriented by the action of two magnetic fields simultaneously.
The hereinabove disclosed method of orienting successive bodies can be performed by an apparatus shown schematically in FIG. 3.
It can be seen from FIG. 3 that the apparatus comprises an electromagnet 8 with a winding 9 adapted to be supplied with alternating electric current, and a pair of pole pieces 10 and 11, the pole piece 10 being wedge-shaped, with the pointed edge facing the orientation zone, the pole piece 10 being positioned for the spacing of its pointed edge from the path of travel of a body 12 being oriented to be substantially constant throughout this path within the orientation zone (if the body 12 is facing the pole piece 12 with that one of its sides which has a smaller value of electric conductivity than the opposite one). The opposite pole piece 11 of the electromagnet 8 has a V-shaped cut aligned with the wedge-shaped portion of the pole piece 10. The spacing between the pole pieces 10 and 11 may be adjusted by moving the pole piece 11, to correspond to the thickness of the body 12 and the range of its possible positions in a direction, normal to the pointed edge of the wedge-shaped pole piece 10. The wedge-shaped configuration of the pole piece 10 provides for a desired degree of non-uniformity of the magnetic field in the orientation zone.
The apparatus shown in FIG. 3 further comprises a second electromagnet 13 whose winding 14 is adapted to be supplied with alternating electric current having a frequency different from that of the alternating current supply to the winding 9 of the electromagnet 8. The pole pieces 15 and 16 of the electromagnet 13 have flat end faces, facing each other and the orientation zone. The electromagnet 13 prevents rotation of the body 12 about an axis parallel to the pointed edge of the wedge-shaped pole piece 10, i.e. it maintains a desired angular position of the main plane of the body 12, as it falls through the orientation zone. However, it is possible to prevent the abovedescribed rotation of the bodies being oriented by other means, e.g. by rigid guideways.
As an example of the operation of an apparatus, embodying the invention, let us consider the operation of orienting a flat body in the form of a bi-metal plate 17 (FIG. 4).
The FIG. 4 shows schematically (in an axially sectional view) the arrangement of the pole pieces 10 and 11 and a pair of chutes 18 and 19 used, respectively, for supplying successive plates 17 into the orientation zone and for delivering the oriented plates 17 therefrom.
In FIG. 4 that side portion of the plates 17, which has a smaller value of electric conductivity, than the opposite one, is unhatched, while the opposite side portion with the greater electric conductivity is hatched.
As a successive plate 17 leaves the open end of the chute 18 and falls through the orientation zone, the path of its free fall is determined by the value of the electrodynamic force "F" applied thereto, this value, in turn, on depending on which side of the plate 17 is facing the pointed edge of the wedge-shaped pole piece 10. As the value of the electrodynamic force "F" decreases with the plate 17 moving away from the pointed edge of the pole piece 10 (the plate 17 being repelled by the action of the field produced by this pole piece), it is advisable, in order to obtain more positive results, for the path of the fall of the plate 17, when it moves with its side portion of the smaller electric conductivity facing the pole piece 10, to be uniformly spaced from the pointed edge of the pole piece 10, which should provide for the plate 17 positively getting into the proper one of the two branches of the delivery chute 19. This can be attained by setting the pole piece 10 at an appropriate angle ".alpha." to a vertical plane.
When a successive plate 17, as it falls through the orientation zone, faces the pole piece 10 with its side portion having the greater electric conductivity, it would be more strongly repelled by the pole piece, whereby the path of its fall would be more greatly deflected from the pointed edge of the pole piece 10, and the plate would arrive in the other one of the two branches of the delivery chute 19.
As a result of the abovedescribed orientation operation, every one of the successive plates 17 would be positioned in either one of the two branches of the delivery chute 18, with the side portion of each plate, which has the greater electric conductivity, facing upwardly.
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