US2801750A - Magnetic separator - Google Patents

Description

-Aug. 6, 1957 R. G. SWANSON MAGNETIC SEPARATOR 3 Sheets-Sheet 1 Filed Aug. 5, 1953 IN V EN TOR.

wfiflwm ATTORNEYS Pou- I G SWA/VSO/V WW R. G. SWANSON MAGNETIC SEPARATOR Aug. 6, 1957 s Sheet s-Shee't 2 Filed Aug. 5, 1953 1957 R. G. SWANSON 2,801,750

MAGNETIC SEPARATOR Filed Aug. 5, 1953K 3 Sheets-Sheet 3 Fic.7

V INVENTOR.

POL/- G. 5 1M4/vs0/v mwmw United States Patent C) MAGNETIC SEPARATOR Rolf G. Swanson, Minneapolis, Minn., assignor to Strong- Scott Manufacturing Company, Minneapolis, Minn., a corporation of Minnesota Application August 5, 1953, Serial No. 372,583 8 Claims. (Cl. 209-223) This invention relates to magnetic separators and particularly relates to magnetic separators of the permanent magnetic type adapted to be utilized in connection with a delivery spout or chute.

In the delivery of mobile non-magnetic materials, and particularly finely divided materials such as grain, through a chute or spout, there is always a certain amount of tramp iron or other magnetic material which must be removed from the grain or other non-magnetic material as the mixture flows through the spout, usually by the action of gravity. Thus, nuts, bolts, nails, tacks and shards of metal are often mixed with grain to the subse quent detriment of cattle or machinery.

It has been proposed to provide a magnetic separator positioned in the chute or spout where the mixture will flow over the separator for the removal of tramp iron or other magnetic material from the mixture as it flows thereover. It is to such a separator that this invention is specifically directed.

It is an object of this invention to provide a perma-. nent magnet type separator so constructed so that tramp iron or other contaminant magnetic material is stopped and held from flowing thereover.

It is another object of this invention to provide a magnetic separator of the self-cleaning type.

It is another object of this invention to provide a permanent magnet type separator designed for conduit use whereby magnetic material is held positively in place on the separator until a drop gate is manually lowered into position for discharge.

It is still a further object of this invention to provide in a permanent magnet type separator a means whereby when a drop gate is lowered, the magnetic material can.- not inadvertently continue its fiow down the spout but must discharge below it.

It is a further object of this invention to provide a new and useful permanent magnet type separator in which the magnets are moved from contacting position relative to the spout simultaneously with a drop gate and the magnets are then separated from the drop gate.

Another object of this invention is the provision of means for eliminating or minimizing the possibility of having an air-gap between the pole pieces of a magnetic separator and the magnetic poles. i,

It is still a further object of this invention to provide a permanent magnet type separator designed for spout use having pole pieces for transmitting magnetic flux into the area of fiow of a mixture containing magnetic and non-magnetic material and having means for eliminating or minimizing an air-gap between the poles of the permanent magnets and said pole pieces.

It is a further object of this invention to provide a permanent magnet type separator designed for spout use having pole pieces, and permanent magnets positioned tofloat relative to said pole pieces for providing maximum pull on the surface of the pole pieces.

. It is a further object of this invention to provide a permanent magnet type spout separator having a latch Patented Aug. 6, 1957 2 mechanism which positively maintains a. drop gate in position and permanent magnets in position relative to said drop gate. 1

Still a further object of this invention is the provision of a permanent magnet spout type separator having a latch mechanism for engagement with a drop gate and permanent magnet means whereby the permanent magnet means is prevented from being dropped or forced out of operating position at any time when the drop gate is looked in inoperating position.

Another object of this invention is to provide a spout ype magnetic se r t her in t ma i ma er is automatically discharged when the magnets are placed in inoperative position. i

Still another object of this invention is to provide a magnetic pa or having p man n ma t and pole pieces, in which the pole pieces and magnets are exposed to view when the magnetic material is being discharged.

To the accomplishment of the foregoing and related ends this invention then comprises the features herein: after fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

This invention will be described with reference to the drawings in which corresponding numerals refer to the same parts and in which:

Figure 1 is a fragmentary elevational view of my invention in position in an open delivery spout;

Figure 2 is a substantially top plan view of the apparatus of Figure 1 taken at right angles to. the spout floor;

Figure 3 is a view similar to Figure 1 but in vertical section;

Figure 4 is a vertical sectional view taken along the line and in the direction of the arrows 44 of Figure 2;

Figure 5 is a vertical sectional view through one of the magnet mounts;

Figure 6 is a fragmentary elevational view of my invention in a modified form of delivery spout; and

Figure 7 is a substantially vertical sectional view taken along the line and in the direction of the arrows 7-7 of Figure 6.

Referring now to the drawings, and particularly to Figures 1-5, there is shown my magnetic separator, gen erally designated 10, in position in a spout 11A11B. The spout 11A11B as shown in Figures 1-4, is of conventional construction comprising a substantially U- shaped metallic channel having an open top and adapted to transfer material such as grain or other comminuted material from one place to another down an incline by the force of gravity. In Figures 6 and 7, a closed spout or chute of wooden construction is shown. It is, of course, to be understood that my invention may be used in any delivery apparatus having a bottom over which a mixture of magnetie and non-magnetic material flows. While it is preferable to have a spout or chute, inclined as shown in Figures 1 and 6, my invention may be used with a level spout or chute, if desired.

The spout of Figures 1-4 comprises a bottom or floor 12, with gussets 13 forming inclined side wall portions which join bottom 12 to side plates 14 as is shown best in Figures 1 and 2. The floor 12, gusset-s 13 and plates 14 are placed as illustrated in those figures. Plates 14 are secured to the floor 12 and the gussets 13 and serve as supporting frame members. They are supportedby any suitable means, not shown. The spout, in this instance, comprises the two sections 11A and 1113 having cooperative inclined bottoms 12 so that when the separator, en ra e g ate 10, is e ted th s stwesn a tinuous U-channel for the flow of the mixture of magnetic and non-magnetic material therethrough is provided.

The spout section 11A is provided with a pair of angle uprights 15 at its terminal edge adjacent the separator 10. Uprights 15 are each provided with a pair of vertical webs extending at right angles to one another, as is conventional. Thus, one web extends in the place of the side walls 14 and the other web extends at rig-ht angles thereto. In this instance, the web extending at right angles thereto has been removed down to the juncture of upright 15 with the upper edge of floor 12, as shown in Figure 1, so that uprights 15 from their juncture with the upper edge of fioor 12 to the top edge of the section 11A comprise fiat webs secured to side plates 14 of section 11A.

Likewise, spout section 11B is provided with a pair of angle uprights 18 which have correspond-ing webs removed down t their juncture with the upper edge of floor 12 so that uprights 18 from their juncture with the upper edge of floor 12 to the top edge of the section 11B comprise flat webs secured to the side plate 14 of section 11B.

Secured to corresponding members of pairs of up rights 15 and 18 are angle braces 16 for supporting separator frame 19.

The separator consists of a welded frame 19 made of non-magnetic material such as aluminum and is supported by the spout sections 11A and 11B by being positioned and supported by members 15, 16 and 18. The frame, as shown best with reference to Figures 3 and 4, comprises a pair of side plates 20 having triangular apertures 21 therein. Plates 20 are joined by a front angle brace 22 having a downturned edge 23.

Gussets 24, similar to and cooperating with gus-sets 13, are secured to side plates 20 and to longitudinal braces 25.

Longitudinal braces 25 combine with angle brace 26, having an extending flange 28, and angle brace 29, having an extending flange 30, both flanges being in the inclined plane of the bottoms 12 of spout sections 11A and 11B, to form an integral rectangular frame as shown best with reference to Figures 3 and 4. Flanges 28 and 30 cooperate with the floor 12 of spout sections 11A and 11B and intermediate cooperating floor sections 31 and 32 to provide a relatively smooth inclined surface for supporting the flow of material.

Attached to the vertical web of longitudinal braces 25 by a hinge pin 33 for pivotal movement thereabout, is a magnet mounting plate 34 which is made of non-magnetic material. Supported on plate 34 is a plurality of U- shaped or horseshoe permanent magnets 35 which are loosely retained in position thereon by means of a nonmagnetic mounting bar 36 which is firmly held in place by bolts 38 which immovably position it on spacers 39 secured to mounting plate 34.

The magnets 35 are retained in position relative to the mounting plate 34 by means of non-magnetic pins or studs 40 held in place by means of nuts 41 and having reduced upper ends 42 extend-ing into apertures 43 of bosses 44, one at each end of each horseshoe magnet as shown best with reference to Figure 5. It may be noted, specifically with reference to Figure 4, that the reduced portions 42 of pins 40 are of a smaller diameter than the diameter of the apertures 43 in which they are located. Thus, the pins serve to generally locate the magnets which are prevented from separation from the plate 34 by means of U-bars 36, bolts 38 and spacers 39, but which are permitted to move relatively freely without restriction as later explained more fully.

A drop gate, generally designated 45, of non-magnetic material, is pivoted by pin 46 to the vertical webs of braces 25, as shown best in Figure l. The drop gate comprises a U-frame comprising a pair of side bars 48, secured to an angle front bar 49. Planar members 50 and 51, attached thereto, are composed of non-magnetic material. Secured to the drop gate 45 is a pair of pole pieces 54 separated by a non-magnetic spacer 55, as shown best with reference to Figures 2 and 3. One of each of the pole pieces is positioned for cooperation with one of the machined faces of each of the horseshoe magnets 35, as shown best in Figure 3. Thus, four horseshoe magnets are shown with reference to Figure 4, each having two machined faces, which cooperated with the pole pieces 54.

Secured to lug 56 of the magnet mounting plate 34 is a handle 58 which may be grasped to pivot the mounting plate 34 around pivot pin 46.

A lockbar shaft 60 is passed between the side plates 20 and is provided at one end with a retaining collar 61, abutting bearing plate 62 which is secured to one of the side plates 20 as shown in Figure 4. Aifixed to the other end of the shaft 60' is a handle having a thumb plate 63 and an extension, 64 in which is positioned asymmetrical depression 65. The handle is secured to shaft 60 by collar 66 which abuts a bearing plate 68 similar to bear-ing plate 62. Positioned on shaft 60 is a pair of lockbars '76 secured thereto by collars 71 and having lock extensions 72 provided with rounded ends as shown in Figure 3, which serve to engage the underside of bars 48.

Thus, itwill be seen that the magnets 35 are mounted upon plate 34 and provided with spacer 39 limiting separating movement thereof. The spacers 39 are of sufficient extension to permit vertical movement of each magnet 35 so that its machined pole faces will be free to pull themselves against the machined undersides of the soft iron pole pieces 54, to provide positive metal-to-metal contact. This markedly increases the transferral of the magnetic flux through the pole pieces and consequently into the area of flow.

In the operative position of Figures 1 and 4, the magnets 35 and mounting plate 34 are held in position against drop gate 45 by the magnetic attraction of the magnets 35 against the soft iron pole pieces 54. The handle 58 1S rigid-1y attached to the mounting plate 34 to provide a means for pulling the magnets downwardly or counterclockwise with reference to Figures 1 and 3 into the -1n operative position shown in dotted lines in Figure 3, in which position they are retained by gravity. The handle 58 is also used to bring the magnets back into the operative position of Figures 1 and 4.

The drop gate 45, when in the position of Figures 1 and 4, closes any opening at the bottom of the U-shaped delivery chute or spout. Thus, in the position of Figures 1 and 4, bottoms 12 of sections 11A and 11B, sections 31 and 32, extensions 28 and 38, sections 50 and 51 and pole pieces 54 together with spacer 55, cooperate to provide a continuous uninterrupted floor surface over which the mixture of non-magnetic material containing the tramp iron will flow. The drop gate 45 is arranged to swing downwardly for the removal of magnetic material which will be retained thereon as it passes thereover in the flow of the mixture. The drop gate 45 is retained in the position of Figures 1 and 4 by the engagement of extensions 72 with the underside of bars 48 in slightly over-center position with reference to a perpendicular dependent from said bars. The extensions 64, having the asymmetrical depression 65, serve to retain and lock the magnets 35 in position against the pole pieces 54 so that they cannot be removed or separated therefrom when the drop gate is in this position. This is accomplished by the mating of the handle 58 in asymmetrical depression 65.

Thus, when the drop gate 45 is in position to close the opening in the chute, the magnets must necessarily be in operating position. When the lever 63 is moved so as to release extensions 72 from bars 48 and thus to move the drop gate 45 to the position of Figure 3, handle 58 is automatically disengaged from the asymmetrical depression 65 and the handle 58 may then be moved from the full line position of Figure 3 to the dotted line position to separate the magnet mounting plate 34 from the drop gate 45. It will be noted that the drop gate 45 in the position of Figure 3 impinges on the shaft 60 and is thus prevented from further counterclockwise motion. As the drop gate 34 is" moved from the positlon of Figure l to that of Figure 3 magnetic material Will be retained on the pole pieces 54 and the angle of incline of the drop gate will be increased. When the magnets 35 are then moved from the full to the dotted line position of Figure 3, the tramp iron or caught material will fall from the demagnetized soft iron pole pieces 54 into a Suitable receptacle.

The separator may be used together with baifies or barracades which extend across the chute or spout to slow up the flow of material or to thin out the flow directly over the magnetized pole pieces 54. t

In operation, the material flows down the chute or spout, and the spout is usually positioned at an angle of incline of 25-40. The material will usually flow in a layer of the depth of one and one-half inches. While the magnets 35 and drop gate 45 are in the operating position, any tramp iron or "magnetic material which may be present is pulled into contact withthe pole pieces 54 and is held thereon. When it is desired to discharge the magnetic material, the flow of the material is stopped in any of the usual ways, the lever 63 is then moved clockwise with reference to Figures 1, 2 and 4, releasing the drop gate 45 which falls in a counterclockwise direction to the position of Figure 3 under the action of gravity. Handle 58 is then manually depressed in a counterclockwise direction, causing the magnets 35 and the mounting plate 34 to swing from the full to the dotted line position of Figure .3. Gravity holds the magnets in this inoperative position. In this position the pole pieces 54 become demagnetized and the tramp iron or other magnetic material is discharged by gravity. In the event small pieces cling to the surface of the pole pieces 54, they can be readily removed simply by hand, by jarring the drop-gate 45 against shaft 60.

When it is desired to resume operation, the handle 58 is pulled upwardly or in a clockwise direction until the magnets 35 pull themselves into intimate contact with the pole pieces 54. It is to be noted at this time that the pole pieces 54 are fully magnetized whenever they are in operative position in the spout, or in the position of Figures 1, 2 and 4, thus preventing any accidenta'l discharge into the spout of magnetic material which may have remained on the pole pieces or which may have been lodged in the spout .at some point above the separator. After the magnets 35 have made contact with pole pieces 54, the lever 63 is pulled upwardly or in a counterclockwise direction with reference to Figure 3, causing the lockbar extensions 72 to make contact with the underside of bars 48 and close the drop gate firmly. in place against member 28 as it swings to the position of Figures 1, land -4. The'upward movement f.the lever 63 is continued until the asymmetrical depression 65 makes contact with the handle 58 at which time lockbars 7t? have assumed a position slightly overcenter in relation to their movement against the underside of bars 48. This position insures positive locking of the gate against its being opened by pressure from its upper side. Any pressure on this surface will tend to rotate the lockbars 70 and extensions 72 downwardly, which movement is restrained by the contact of the asymmetrical depression 65 with handle 58.

Referring now specifically to Figures 6 and 7, there is shown a slightly modified form of my invention. In this form, instead of being positioned in a metallic chute, as is the modification shown in Figures 15, my invention is positioned in place in a wooden chute. Likewise, the modification of Figures 6 and 7 shows a closed chute in contrast to the open chute of Figures 1-5. Thus, with reference to Figures 6 and 7, there is shown a spout or chute generally designated 80 having a top 81, a bottom 82 and sides 83, thus providing a rectangular enclosure through which the grain or other finely comminuted material is adapted to flow. A pair of depending strap hangers 84 are secured by wood screws 85' to sides 83 and serve to support the lockbar shaft 60.

In this instance the rectangular frame; 25, 26 and 29 is supported by attachment to the wooden side walls 83 by a plurality of wood screws 86 shown in Figures 6 and 7. Otherwise the function of this mechanism is identical with that shown in Figures 1-5.

Referring specifically to Figure 6, there is shown a further modification of my invention in which magnets 35 are provided which are fixedly and immovably positioned upon mounting plate 34 by use of spacers 40A and mounting bar 36. Mounting plate 34 in this instance is provided with a hinge pin 33A having an elongated aperture 3-33 therein. Elongated aperture33B is perpendicular to the bottom of the chute and thus permits movement of the hingepin in the direction of the double arrow 33C. Inasmuch as the magnets 35 are fixedly mounted, it is in this instance'the provision of theelongated hingepin 33A which permits the magnetic attraction of the magnets for the pole pieces to draw the machined faces of the magnet in engagement with the pole pieces. However, it is to be understood that the embodiment shown in Figure 6 is not as preferred as the embodiment of Figures 1 5, inasmuch as the complete flexibility of engagement of the modification of Figures 1-5 is not present.

As many apparently widely differing embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments disclosed herein.

What I claim is:

l. A permanent magnet type spout separator comprising in combination a conduit down which a mixture of magnetic and non-magnetic material is adapted to slide, a drop gate pivotally positioned on said conduit com, prised of non-magnetic material, pole piece means positioned on said drop gate comprising a material adapted to be magnetized by contact with a permanent magnet, a permanent magnet mounting plate pivotally supported relative to said drop gate and substantially parallel thereto, a plurality of permanent magnets supported .on said mounting plate having magnetic faces adapted to engage said pole piece means, a first handle means positioned on said mounting plate, a pair of lockbars pivoted beneath said conduit and adapted to engage the underside of said drop gate for locking the same in position, second handle means for pivoting said lockbars to an over-center locking position, said second handle means cooperating with said first handle means on said drop gate for locking said drop gate and said mounting plate in engagement.

2. A magnetic separator comprising in combination a conduit surface over which a mixture ofmagnetic and non-magnetic material is adapted to slide, a pprtion of said conduit surface being removable, said portion ineluding planar pole piece means providing an undersurface, a magnet means having spaced planar faces, said spaced planar faces being normally positioned in substantially complete abutment with the undersurface of said pole piece means, removable magnet supporting means whereby said magnet faces may be completely removed from said pole piece means, said magnet supporting means including means permitting translation of said magnet means in a direction substantially normal to the undersurface of said pole piece means and into said abutment therewith and permitting tilting of said magnet means, and means providing a limit for said translation of said magnet means at a position beyond engagement of said magnet faces with the underside of said pole pieces whereby translation of said magnet means in the direction of said pole pieces is normally limited by engagement of said faces therewith for telescoping of said magnet means on said magnet supporting means.

, 3. The apparatus of claim 2 further characterized by said magnet means being loosely positioned on pin means substantially perpendicular to said planar faces.

4. A magnetic separator comprising in combination a conduit surface over which a mixture of magnetic and non-magnetic material is adapted to slide, including planar pole piece means comprising a portion of said surface and providing an undersurface, a magnet means having'spaced planar faces, said spaced planar faces being normally positioned in substantially complete abutmentwith the undersurface of said pole piece means, removable magnet supporting means to which said magnet means is secured whereby said magnet faces may be completely removed from said pole piece means, said magnet supporting means including a pair of studs, said magnet means having a pair of spaced apertures, said studs loosely positioned in said apertures and permitting translation of said magnet means in a direction sub stantially normal to the undersurface of said pole piece means and into said abutment therewith and permitting tilting of said magnet means, and means retaining said magnets from separation from said studs and providing a limit for said translation of said magnet means at a position beyond engagement of said magnet faces with the underside of said pole pieces whereby translation of said magnet means in the direction of said pole pieces is normally limited by engagement of said faces therewith for telescoping of said magnet means on said magnet supporting means.

5. A magnetic separator comprising in combination a conduit surface over which a mixture of magnetic and non-magnetic material is adapted to slide, and including planar pole piece means providing an undersurface, a magnet means having spaced planar faces, normally positioned in substantially complete engagement with the undersurface of said pole piece means, removable magnet supporting means to which said magnet means is secured whereby said magnet faces may be completely removed from engagement with said pole piece means, means permitting translation of said magnet means in a direction substantially normal to the undersurface of said pole piece means and into engagement therewith, and permitting tilting of said magnet means with respect thereto, and means whereby translation of said magnet means in the direction of said pole pieces is normally limited by engagement of said faces therewith.

6. In a magnetic separator, an extending plate f0rming a surface over which a stream of magnetic and nonmagnetic material is adapted to slide in a given direction, pivot means pivotally supporting said plate at the upstream end whereby it may be pivoted from a first position wherein it forms a prolongation of a conduit surface to a second position declined at an acute angle with respect thereto, said plate means including magnetizable pole piece means, magnet means secured to' a magnet support to engage the underside of said pole piece means when it is in said first position, said magnet support being pivoted adjacent the pivoted end of said plate whereby said magnet means may be pivoted into or out of communication with said pole piece means, said magnet means normally retained in engagement with said pole piece means by its magnetic attraction,. a projecting handle means secured to said magnet support and adapted to be grasped by an operator for pivoting it about its pivot, and stop means positioned to limit pivotal movement of said plate means at said second position at said acute angle with reference to said conduit surface whereby pivotal movement of said magnet support will first pivot said plate means, magnot support and magnet means as a unit but will disengage said magnet support and magnet means from said plate means as said plate means engages said stop means. 7. The structure of claim 6 further characterizedby releasable means for locking said plate in said first position and said magnet support to said plate.

8. In a magnet separator, a drop gate forming a surface over which a mixture of magnetic and non-magnetic material is adapted to slide, pivot means pivotally supporting said drop gate at one end whereby it may be pivoted from a first position wherein it forms a prolongation of a conduit surface to a position declined with respect thereto, said drop gate including magnetizable pole piece means, magnet means secured to an elongated magnet support to engage the underside of said pole piece means when it is in said first position, said magnet support being pivoted adjacent the pivoted end of said drop gate whereby said magnet means may be pivoted into or out of communication with said pole piece means, said magnet means normally retained in engagement with said pole piece means by its magnetic attraction, a first handle means secured to said magnet support and adapted to be grasped by an operator for pivoting it about its pivot, a pair of lock bars pivoted beneath said drop gate and adapted to engage the underside thereof for locking the same in position, second handle means for pivoting said lock bars to an over-center locking position, said second handle means cooperating with said first handle means on said drop gate for locking said drop gate and said mounting plate in engagement.

References Cited in the file of this patent UNITED STATES PATENTS 2,340,303 Byrd Feb. 1, 1944 2,461,008 Stearns Feb. 8, 1949 2,502,096 Kotilinek Mar. 28, 1950

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