US2461008A - Magnetic separator - Google Patents

Description

Feb 9- R. H. STEARNS 2,461,008

meumxc SEPARATOR Filed May 51, 1945 2 Sheets-Sheet 1 I N V EN TOR. 4 7/ 23 flan/m a JffA/P/VJ Feb. as, 1949. Hm-14mg- 2,461,008

MAGNETIC SEPARATOR Filed May 31, 1945 2 Sheets-Sheet 2 Patented Feb. s, 1949 MAGNETIC SEPARATOB Roswell H. Stearns, Wauwatosa, Wla, aulgnor to Stearns Magnetic Mfg. 00., Milwaukee, Wis., a corporation 'of Wisconsin Application May 31, 1945, Serial No. 590,910

This invention relates to magnetic separators and is particularly directed to permanent magnet spout type separators.

The primary objects of this invention are to provide a permanent magnet spout. type separator which is so constructed that tramp iron or other magnetic material is removed from nonmagnetic material as'the mixture slides or flows down the spout, which holds the magnetic material until the magnet is moved to inoperative position, which operates a trap gate toopen the trap gate when the magnet is moved to inoperative position and which closes the trap gate when the magnet is moved back to operative position, in which the action of the trap gate is positive and automatic and cannot be interfered with, and in which no i 3 Claims. (Cl. 209-228) Figure 1 showing the magnet in inoperative position and the trap gate in open position.-

Referring to the drawings it will be seen that a spout or chute isindicated by the reference character I, down which the material is adapted to flow, such material being a mixture of nonmagnetic material such, for example, as grain or feed, and magnetic material such, for example, as

- tramp iron.

latch or other similar means is required to hold the magnet in operative or inoperative position but in which the magnetic attraction of the permanent magnet itself is employed to positively hold the magnet in operative position and the trap gate closed and in which gravity is efiective to hold the permanent magnet in7inoperative position and the trap gate open.

A further and important object is to provide a permanent magnet spout type separator which is arranged to insure the automatic release and discharge of magnetic material when the permanent magnet is moved to inoperative position to thus avoid the necessity of manually removing th magnetic material.

It has been found that with permanent magnets, such as those composed of "Alnico for instance, that when a piece of tramp iron comes into proximity to the magnet that there does not seem to be an immediate rearrangement of the lines of force or flux from the permanent magnet and consequently the pull or force acting on the tramp iron is not as effective or great and does not reach its maximum value as quickly as would be expected. This invention, however, has forv its further objects provisionof means for correcting this defect so that the pull or force acting on the tramp iron is enhanced and the effect is substantially instantaneous so as to insure the catchstructure shown in Figure l.

Figure 3 is a sectional view corresponding to The separator is adapted to be installed in the bottom wall of the chute by cutting out a portion of the chute and securing an open angle iron welded frame 2 to the chute by means of screws or other suitable fastening means 3, such screws passing upwardly into the side walls of the chute or spout.

A pair of lugs 4 are rigidly carried by the frame adjacent its upper end and project downwardly therefrom. These lugs may be welded or otherwise secured to the frame.

The magnet structure indicated generally by the reference character A is composed of a per-' manent, centrally located magnet 5 which may be of any suitable permanent magnet material such as Alnico." It is provided with a flared upper portion 6 and is welded or otherwise secured at its bottom end to a bottom plate or bar l of soft iron or soft steel. Two upright soft iron or soft steel bars or plates 8 and 9 extend upwardly from the bottom plate 1 and are welded or otherwise secured thereto. The upper faces of the portions 6, 8 and 9 are accurately ground or machined and adapted to come. into intimate contact with the soft iron or soft steel magnetic .the spaces between the upper end and sides of the frame and between successive pole pieces. These sheets or plates may be formed of any suitable ,materiaL' for example, nonmagnetic stainless steel. The upper plate or sheet is indicated by the reference character I5 and extends from the upper end of the frame andfrom the sides ofthe frame to the pole piece i2. It is welded to the frame and to the pole piece. The

next sheet is indicated by the reference character- I6 and extends from beneath the pole piece l2 to the upper edge of the pole piece II and is welded to such pole pieces and to the frame. The third sheet is indicated by the reference character I? and is similarly'weided to the underside of the pole piece it andextends upwardly to the upper edge of the pole piece I3 and is welded thereto and to the frame. The last sheet is indicated by Means are provided for pivotally supporting the magnet so that it may be rocked from operative position, as shown in Flgure'l, to inoperative position as shown in Figure 3 or back to operative position as shown in Figure 1. This means consists of a pintle pin or shaft I! which passes through a pair of lugs 2| rigid with the magnet structure A and through the lugs 4 to thus pivotaiiy Join the magnet to the frame adjacent the upper side or end of the magnet structure. Suitable spacers as shown in Figure 2 may be employed and posltioned'between the lugs 2| and l.

No latches are required for retaining the magnet in either its operative position or in its inoperative position. In its operative position, as shownin Figure l, the magnetic attraction between the magnet structure and the pole pieces firmly and positively holds the magnet in operative position. When the magnet is pulled down to the inoperative position, as shown in Figure 3, gravity retains the magnet in this position. Any suitable means such, for example, as a handle Ii projecting from one side of the magnet may be provided for rocking the magnet to either position.

A trap gate indicated by the reference character 22 is provided and is preferably of channel shape and is pivotally mounted on a pintle pin or shaft 23 carried by the frame 2.

This trap gate when in closed position has its upper end positioned beneaththe plate or shield II. It is provided with a normally downwardly projecting member .24 which normally lies on the upper side of the frame 2 and which when the trap gate is in its open positlon,.as shown in Figure 3, extends upwardly and constitutes a barrier for arresting thedownwardly traveling released tramp iron so that the tramp iron will ;be discharged through the opening adjacent the trap gate. The trap gate is preferably weighted by means of a pair of bars of iron or other heavy material indicated by the reference character 25 which may be welded or otherwise secured to the inner sides of the trap. gate. A pin or bar 28 extends transversely across the trap Lgate and projects beyond one side thereof as shown most clearly in Figure 2. This I pin or bar is adapted to be engaged by a projecting finger or member 21 when the magnet structure is rocked downwardly to inoperative positionto thus positively rock the trap gate toopen position. The weight of the trap gate will hold the trap gate in open position as shown in Figure 3.

The comer portions or lower end portionsfl',

see Figure 3, of the trap gate abutting the side flanges of the frame 2 constitute stops to hold the trap gate in the position shown in Figure 3. The finger or member 21 is an integral part of a bracket or arc-shaped portion 28 rigidly .secured to one side of the magnet structure. This bracket is providedwith a cam portion 29 which is arranged to engage the pin 25 when the magnet is rocked from its inoperative position shown in Figure-8 to its operative position shown in Figure l to thus close the trapgate and hold the trap gate in its closed position.

It is preferable to provide a small barrier 10 which extends transversely across the chute in accordance with the usual practice to cause the material to-bound slightly to insure agitation there of as it approaches the pole pieces. In order to prevent any material from bouncing over the pole pieces, a rubber sheet Ii is secured to 'a transverse portion 32- adiacentjthe upper side of the chute and loosely bears against the 4 plate II. It has been found that the curvilinear miter sheet Ii, in conjunction with the barrier or baiiie 30, causes the material to fall directly downwardly on the face of the magnet and materially slows up the flow of material temporarily at the magnet poles. By actual observation it has been found the material substantially stops at the magnet poles for a brief instant, and thus It and is retained thereby.

allows sufficient time for the magnetic forces to grip and hold all of the magnetic material while the nonmagnetic material is allowed to pass.

In using the separator the material is allowed to flow down the chute while the magnet is in its operative position as shown in Figure 1 and the tramp iron or other magnetic material comes in direct contact with the pole pieces ii, I! and Such magnetic material may be swept downwardly slightly by the oncoming material but, nevertheless, it will lodge in the spaces just above the plates l8 and l I even if it is not securely held against the face of the pole pieces.

It is to be noted that the pole pieces II, II. and it are relatively thick and insure adequate magnetic material to allow substantially instantaneous shifting of the lines of force or flux as the tramp iron approaches these magnetic poles and to thus enhance the force or pull on the tramp iron and alsosecure substantially instantaneous response. Substantially no shifting of the lines of force or magnetic flux takes place in the pennanentmagent 5 but by means of the construction hereinabove set forth provision is made to allow substantially instantaneous shifting of flux or lines of force as required and as v has been explained hereinabove.

when it isdesired to discharge the magnetic material the feed is stopped in any of the usual ways, not shown, and the handle is grasped and forced downwardly thus rocking the magnet structure). from its operative position as shown in Figure-1 tothe inoperative position as shown in Figure 3. During the first portion of this rocking motion the finger 2i positively moves the trap gate 22 to its open position as shown in Figure 3. Gravity retains the magnet A and the trap gate in their respectively inoperative and open positions. When it is again desired to place the magnet in operative position the handle 2i is pulled upwardly until the magnet structure A intimately contacts the pole pieces ii, i2, and i3.

During the latter portion of this motion the cam position, as shown in Figure 1, and holds the trap, gate'in closed position. It is to be noted particularly that no latches whatsoever or similar devices are employed to retain either the magnet or the trap gate in closed position. The magnetic attraction of the magnet is employed to positively hold the magnet in operative position and the trap gate closed and gravity is relied upon to hold the magnet and trap gate in their respectively inoperative and open positions. 4

It will be seen that a novel permanent magnet spout type separator has been disclosed which is of very simple and effective construction and which may be cheaply made and readily installed.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting. as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A permanent magnet spout type separator comprising a downwardly slanting spout down which a mixture of magnetic and nonmagnetic material is adapted to slide, a plurality of soft steel pole pieces of magnetizable material permanently mounted in said spout in position for the material to pass thereover, a magnet structure comprising in combination a permanent magnet and a U-shaped yoke of magnetizable material hingedly supported from and below said spout and bodily movable as a composite unit upwardly into and out of contact with said pole pieces to respectively energize and deenergize said pole pieces, a trap gate carried by said spout for discharging magnetic material, and means for mechanically connecting said magnet structure and said trap gate to positively close and open said trap gate when said magnet structure is respectively moved into and out of contact with said pole pieces, the weight of said magnet structure being temporarily overcome by the magnetic attraction of said magnet structure to thereby hold said magnet structure temporarily in position against the action of gravity.

2. A permanent magnet spout type separator comprising in combination a magnet structure having a center pole of permanent magnetic alloy steel and end poles of soft steel aflixed to a common bridge bar of soft steel to thereby provide twin fields of unlike magnetic polarity, a downwardly slanting spout down which magnetic and nonmagnetic material is adapted to slide, said spout comprising a structural frame of nonmagnetic material, a plurality of soft steel pole pieces permanently located in said'spout and arranged to have the mixture pass over said soft steel pole pieces, said soft steel pole pieces being inductively magnetized when the magnet is in operable position and demagnetized when in nonoperable position, a swinging trap gate mounted in said spout, said trap gate when in the open position arranged to arrest and discharge magnetic material and when in closed position to permit nonmagnetic material to flow through said spout, said magnet I trap gate to open position when the magnet is moved to inoperative position for discharge of magnetic material, said trap gate trip having a curved arc-shaped portion arranged to positively close said trap gate bysliding contact with said trap gate when the magnet is returned to its normal operating position.

3. A permanent magnet spout type separator comprising a downwardly slanting spout down which a mixture of magnetic and nonmagnetic material is adapted to slide, a plurality of soft steel pole pieces of magnetizable material permanently mounted in and arranged to have the mixture pass over said soft steel pole pieces, and a magnet structure comprising in combination a permanent magnet and a U-shaped yoke of magnetizable material hingedly supported from said spout and movable into and out of contact with said soft steel pole pieces, said hingedly supported magnet structure being held in operative position in contact with said soft steel pole pieces until manually released solely by the magnetic attraction of said hingedly supported magnet structure, said spout having in combination a projecting bafie to cause material to bound upwardly, and a curvilinear sheet member located above the magnetic field to cause material to strike said sheet and drop directly on the face of said magnet pole pieces to thereby slow down the speed of flowing material momentarily, thus allowing sumcient time for the magnetic forces to grip and hold all magnetic material; while the nonmagnetic material is allowed to pass.

ROSWELL H. STEARNS.

REFERENCES crrnn ,The following references are of record in the file of this patent:

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