US2310736A

US2310736A - Double screen structure

Info

Publication number: US2310736A
Application number: US345598A
Authority: US
Inventors: Oscar C Gruender
Original assignee: Nordberg Manufacturing Co
Current assignee: Nordberg Manufacturing Co
Priority date: 1938-06-11
Filing date: 1940-07-15
Publication date: 1943-02-09
Anticipated expiration: 1960-02-09

Description

Feb 9, 194f3 o. c. GRUENDER DOUBLE SCREEN -STRUCTURE 4 Sheets-Sheet l figg/MM Original Filed June 11.11958 Feb. 9, 1943. .0, GRUENDER 2,310,736

DOUBLE SCREEN STRUCTURE Original Filed June 11, 1938 4 Sheets-Sheet 2 Feb., 9, 1943. o. c. GRUENDER 2,310,736

DOUBLE SCREEN STRUCTURE l original Filed June 11, lsa 4 sheets-she@ s Wzy fie' 'We/?? 05cm" @rae/wier Fel 9, 1943- o. c. GRuENnl-:R

*DOUBLE SCREEN STRUCTURE original Filed June 11, 1938 4 sheets-sheet 4 fiyef? Zoy @Jaar @maeva/62 Patented Feb. 9, 1943 2,310,736 DOUBLE SCREEN STRUCTURE scar C. Gruender, Milwaukee, Wis., assigner to Nordberg Manufacturing Co., Milwaukee, Wis., a corporation of Wisconsin Original application June 11, 1938, Serial No. 213,193. Divided and this application July 15, y 1940, Serial No. 345,598

8 Claims. (Cl. 209-240) My invention relates to improvements in screens and has for one purpose the provision of a screen which shall be simple to manufacture,I

compact, and efficient in use.

Another purpose is the provision of improved means for providing a screen of substantial length in which a plurality of separate units are employed.

Another purpose is the provision of an improved screen frame or deck.

Another purpose is the provision of an improved screen in which a plurality of sections feed the material under the screen in opposite directions, and preferably in such fashion as to cause the discharge from a plurality of sections to join at a unitary discharge area. y

The present application is a division oi my copending application Serial No. 213,193, led in the United States Patent Oiilce on June l1, 1938.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate my invention more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a side elevation; l

Figure 2 is a section on the line 2-2 of Figure 1, on an enlarged scale, with parts omitted;

Figure 3 is a section on the line 3-3 of Figure l, on an enlarged scale;

Figure 4 is a section-on the line 4-4 of Figure 1, on an enlarged scale;

Figure 5 is a section on the line 5-5 of Figure 4; and

Figure 6 is a section on the line 6-6 of Figure 4.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, I generally indicates a normally xed screen frame which may include horizontal top frame members or channels 2, horizontal bottom frame members or channels 3, vertical end frame members 4, 5, inclined braces 1, and screen frame members or channels 8, and intermediate transverse members, channels or angles 9. I0, indicate any suitable hopper members having downspouts or discharge members i2, I3.

Intermediate the hoppers i0 and are any suitable .discharge chutes |20, 2|, the upper chute |20 being adapted to receive the discharge from the upper level of the two screen decks below described, and the chute |2| being adapted to receive the discharge from the lower level of the two said screen decks, as generally indicated at A and B in Figure 1.

In order to deliver material to the screen assembly, I may provide any suitable intermediate feeding means, forv example the member |22, which may be a chute or a belt, discharging to feed chutes |23, |24,`which in turn discharge to initial feed spouts I8 and |8a, located at the opposite ends of the frame member I, which deliver to the screen units or decks A and B, respectively.

It will be understood that the member or conveyor |22 extends generally at right angles to the path of movement of the screens, and it will vbe observed that the conveyors |20 and |2I lie in a vertical plane common also to the conveyor |22, and extending generally at right angles to the path of movement of the'screens.

Referring to Figure 1, I provide the screen decks A and B, each of which may include side plates 25. Extending longitudinally along the sides are

inner channels

26, 21, which may be welded or otherwise secured to the side plates 25, and at the upper iiange of each channel is positioned a smaller channel 28, in which is carried a padl 29 of rubber or suitable yielding and compressiblematerial, herein shown as filling the space between the anges of the channel 28 and extending upwardly above the upper edges of said anges.

Transverse frame members

30, 3| are employed extending between side plates 25 and

channels

26, 21.

As shown in detail in Figure 6, taken in connection with Figure 4, I illustrate

upstanding angles

32, 33 placed back to back on the

members

30 or 3| and extending between them a longitudinal member 34, upon the top of which is mounted an upwardly open channel 35 having therein a pad 36 of yielding compressible material similar to the side pads 29 and running lengthwise of the screen. Two or more may be employed. The screen cloth may be laid over the pads 36 and is preferably formed with an inwardly turned hook-like edge portion 38 which overlies the side pads 29.

39 indicates a lever plate, the toe of which -as at 40 abuts against a small angle iron 4| secured to the upper inner face of the side plate 25. The lower toe 42 sets within the recurved portion 38 of the screenedge. An intermediate portion 43 is apertured to receive the bolt 44 with its outer nut 45. 46 is a coil spring compressed between the nut or its washer 41 and the outer face of the plate 25, whereby the member 44 with its head 48 draws the member 39 inwardly and somewhat downwardly and compresses the edge portion 38 of the screen cloth against the upper surface of the pacl 29. The result is a stretching and a very firm hold on the screen cloth. The lower screen assembly is the same as above described, except that the toe 40 abuts against the lower flange of the channel iron 21. It will be observed that the mesh is at all times mounted upon and resting upon pads of yielding compressible material, and is not at any point gripped between opposed metallic surfaces. The compression may be readily adjusted by rotation of the nut 45. The screen may readily be removed by slacking the nuts 45 and removing the bolts 44.

The structure of the two screens A and B is substantially the same and need not be separately described. Each section is mounted upon a plurality of compound leaf springs generally indicated at 50 in Figure 1. Each one of the spring members may be formed of a plurality of parallel leaves mounted at their upper ends in brackets on the inside of the upper channels 2. Similar brackets 52 are secured to the lower ends of the spring units and to the outer faces of the side plates 25. Thus each one of the spring units A and B is floated on a plurality of leaf springs inclined somewhat from the perpendicular.

I prefer to have the screens feed in opposite directions. For example, the deck A receives its material from the feed spout I8, and the deck B from the feed spout |8a at the opposite ends of the frame. The oversize from the two decks is delivered to the chutes |20 and |2|, and what passes through the mesh of the decks is received by the hoppers I0 and For convenience, I will indicate the upper screen cloth of section A as X and the upper screen cloth of section B as X-|. I will indicate the lower screen cloth of section A as Y and the lower screen cloth of section B as Y-l.

|9 indicates any suitable motor or power source, herein shown as mounted on the screen` frame itself, upon transversely extending angles 20. The motor pulley 2|, through a belt 22, drives a vibrating unit on one of the screen sections.

Referring to the vibrating unit, which in the form of Figure 1 is shown mounted on screen section A, its details will be shown for example in Figures 1, 2 and 3. I illustrate for example reinforcing plates 60 which may be welded or otherwise secured to the side plates 25. Mounted in an aperture in the reinforcing plates 60 is a bearing housing which includes a member 62 having a flange 62a and a generally cylindrical wall member 63 having a flange 63a. Bolts 63h and nuts 63c secure the flanges 62a and 63a to the side plate 25 and the reinforcing plate 60. Secured to the member 63 by means of the bolts 64a is an inner member 64 having a generally cylindrical flange 65 in which is mounted a cylindrical housing and strut member 66. 61 is an outer-,ball or roller race and B8 an inner race, 69 indicating the rollers.

Mounted for rotation with the inner race 68 is a shaft portion 10 having an inner extension 1| which is cut away as at 12 to provide a balance for the outer eccentric structure below described. 13 is an outer member rotating with the shaft and including a labyrinth connection generally indicated as 14 with the member 62, whereby the escape of oil and the entry of dust is prevented. 15 is an eccentric shaft extension from the shaft 10 to the end of which is secured any suitable pulley 16 about which passes the belt 22 where-V by the eccentric structure may be rotated from the motor I9. 11 is an inner roller race mounted on the shaft 15 and surrounded by an outer race 18 with rollers 19 therebetween. Surrounding and associated with the outer race is a knuckle joint 00 of a connecting rod 8| which extends to the opposite screen. The knuckle has labyrinth connections 83 with the pulley 16, and 6l with the member 13, whereby the roller bearings are protected.

At the opposite end of the connecting rod 8| is a split hub 85 which may be compressed as by the bolt 86 and nut 81. It surrounds a connecting structure mounted on the screen unit B which includes an outer sleeve 88, an inner sleeve 89, and an interposed sleeve of rubber or the like which may be vulcanized to the members 88 and 89, whereby the interior deformation of the compressible and yielding member 90 compensates for the slight oscillatory rotation of the member 85 and prevents any metal to metal bearing contact. Positioned within the inner sleeve 89 is a trunnion 9| which may be formed unitarily with a casting 92 having a positioning stud 93 extending inwardly through the side plate 25 and the reinforcing member 60. It may further be held in position as by any suitable bolts 94 and nuts 95. The same nuts and bolts may extend through the outer flange 96 of an inner plate 91, having a cylindrical flange 98 in which is positioned a tubular strut 99. The member 91 has an aperture as at |00 which also receives the inner end of the member 93. Thus a firm vibrating contact is provided for the screen unit.

The trunnion 9| has a reduced threaded end 9|a to receive a washer 9|b and a nut 9|c to secure the sleeve 89 in position. In order to counterbalance the difference in weight of the vibrating unit on screen unit B and the connecting structure on screen unit A, I may provide weights on either or both screen units, as at ||0 on unit A and on unit B as shown in Figure 1.

Where the tubular members or struts 66 or 99 extend across the screen sections, it will be understood that any suitable means may be employed, such as the welded plates |0| for carrying the members 34 thereacross. Since the strut unit is removable, I flnd it preferable to provide a removable connection between the members 34 and the plates |0I, which may include the bolts |02 and nuts |03. The lever plates 39 are cut down as at 39a to pass under the

members

63 and 91.

It will be realized that my description and drawings are in a broad sense illustrative and diagrammatic and that many changes in size, shape, number and disposition of parts may be made. I therefore do not wish to be limited specifically to the devices herein shown except to the extent that I may possibly limit myself in the claims.

It will be understood that, whereas I have shown but a single link 8| at one side of the screen, the link structure may be duplicated on each side of the screen.- In the drawings only one-half of the screen is shown.

This type of screen lends itself to a compact installation in which there is a minimum of lateral length permitted. For instance, I may employ a single main feed spout or conveyor |22, which by branch chutes |23 and |24 may deliver material to be screened to the feed chutes or spouts I8 and |8a. A minimum of longitudinal outward extension of the screen structure is needed and all of the screen material can escape from the screen unit intermediate its length, either through the spouts I20, I2I, or through the spouts I2, I3. 'I'he use and operation of my invention are as follows:

The material is fed by any suitable conveying means, such, for example, as the chutes |22 and I23, to the end delivery spouts I8 and Ila. Thus the material to be screened is delivered to the top mesh X and X-I of the two decks A and B, and moves inwardly toward the adjacent ends of the two decks. The fines sift through the mesh X and X-I and are received on the lower level mesh Y and YI. Here in turn the fines escape through the mesh as the decks A and B are vibrated, and are received in hoppers III and II, and passout through the spouts I2 and I3. The oversize from the upper mesh X, X-I is received by the upper trough |20, and the oversize from the lower mesh Y, Y-I is received by the lower central trough or chute I2I.

The inclination of the springs 50 in opposite direction keeps the screen frames A and B in balance. The two decks, in a broad sense, act as a unit, and I therefore obtain the advantage of a long screen, with a great economy of construction and operation. A single vibratory unit of one screen section is perfectly adequate to vibrate both sections, and the vibrating transmitting mechanism I have shown, including the connecting rod BI, emciently applies a substantially uniform vibration to the two screen sections, which vibration, however, is in opposite directions.

The unbalanced member is enclosed and, shielded by the transverse tubular strut 68. It will be observed in Figure 2 that the center of rotation a of the shaft 10, 1I in relation to the screen section is eccentric in relation to the center of rotation b of the pulley 16. The axis c of the eccentric shaft extension and of the con necting rod connection 80, however, is eccentric to both. In practice, the rotation of the unit thus described results in a vibration having a throw substantially twice the distance separating the center of rotation a of the shaft 10 in relation to the screen section, and the center of rotation c of the eccentric shaft extension 15.

I claim:

l. In a vibrating screen structure, a base, a plurality of screen elements and means for supporting them vibratably upon said base, said screen elements being located end to end, and means for simultaneously vibrating said screen elements including a shaft mounted on one of said elements and extending transversely thereacross in a generally horizontal plane, means for mounting said shaft rotatably upon said screen element, including bearing means eccentric `to the shaft, means for rotating the shaft including a pulley mounted on the shaft, the

axis of the pulley being eccentric to the shaft and to the bearing connections between the shaft and the screen element and being located substantially midway between them, anda link including an eye surrounding an outwardly extending portion of the shaft, and a connection between said link and the other screen element, said shaft and said connection between the link and other screen element being located upon adjacent ends of the two screen elements, and means for supporting said screen elements, including leaf springs secured each at one end to the base and at the other to one of said elements, said springs being inclined substantially from the perpendicular, the springs for each element being generally parallel, the springs for the two elements being inclined in opposite directions from the perpendicular, and at substantially the same angle.

2. In a vibrating screen structure. a base. a plurality oi' screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, each such element having generally horizontal mesh, meansfor imparting simultaneously to said elements a screening and conveying vibration, including a link pivoted at one end to one of said screen elements and having an eye at the opposite end and an eccentric on the opposite screen element penetrating said eye. and means for rotating it and for thereby varying the distance between said screen elements, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements, and unitary means located between the opposed ends of the screen elements for receiving simultaneously the discharge from said screen elements.

3. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other,.each such element having generally horizontal mesh, means for imparting simultaneously to said elements a screening and conveying vibration, including a link pivoted at one end to one of 'said screen elements and having an eye at the opposite end and an eccentric on the opposite screen element penetrating said eye, and means for rotating it and for thereby varying the distance between said screen elements, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements, and unitary means located between the opposed ends of the screen elements for receiving simultaneously the discharge from said screen elements, and means for supporting said screen elements, including a plurality of leaf springs extending from said base to said screen elements.

4. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, each such element having generally horizontal mesh, means for imparting simultaneously to said elements a screening and conveying vibration, including a link pivoted `at one end to one of said screen elements and having an eye at the opposte end and an eccentric on the opposite screen element penetrating said eye, and means for rotating it and for thereby varying the distance between said screen elements, unitary means for feeding material simultaneously from a single source to athe feed ends of said screen elements, and unitary means located between the opposed ends of the screen elements for receiving simultaneously the discharge from said screen elements, and means for supporting said screen elements, including a plurality of leaf springs extending from said base to said screen elements, said leaf springs being inclined substantially from the vertical, the springs of each said screen element being oppositely inclined.

5. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, unitary means f or imparting simultaneously to said elements a screening and conveying vibration, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements, means located between the opposed ends 'of the screen elements for receiving simultaneously the discharge from said screen elements, the means for imparting simultaneous vibration to the screen elements, including a rotary member mounted on one oi said elements, and means for rotating it, and an actuating connection between said rotary member and the other of said elements.

6. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, unitary means for imparting simultaneously to said elements a screening and conveying vibration, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements. means located between the opposed ends of the screen elements for receiving simultaneously the discharge from said screen elements, including a plurality of superposed conveyors extending in a direction generally at right angles to the path of movement of the material across the screen elements and lying in a common vertical plane, and located between the screen elements, the means for imparting simultaneous vibration to the screen elements including a rotary member mounted on one of said elements, and means for rotating it, and an actuating connection between said rotary member and the other of said elements.

'7. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, unitary means for imparting simultaneously to said elements a screening and conveying vibration, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements, and means located between the opposed ends of the screen A elements for receiving simultaneously the discharge from said screen elements, including a plurality of superposed conveyors extending in a direction generally at right angles to the path of movement of the material across the screen elements and lying in a common vertical plane, and located between the screen elements.

8. In a vibrating screen structure, a base, a plurality of screen elements independently mounted upon said base and located generally end to end, with their discharge ends opposite to each other, unitary means for imparting simultaneously to said elements a screening and conveying vibration, unitary means for feeding material simultaneously from a single source to the feed ends of said screen elements, including a main feed conveyor extending along a path generally at right angles to the path of movement of the screens, and sub-conveyors extending laterally in opposite directions from said conveyor to the feed end of each screen, said main feed conveyor being located generally vertically above the discharge ends of the screens, means located between the opposed ends oi.' the screen elements for receiving simultaneously the discharge from said screen elements, including a plurality of superposed conveyors extending in a direction generally at right angles to the path of movement of the material across the screen elements, and located between the screen elements, and lying in the same general vertical plane as the main feed conveyor, the means for imparting simultaneous vibration to the screen elements including a rotary member mounted on one of said elements, and means for rotating it, and an actuating connection between said rotary member and the other of said elements.

OSCAR C. GRUENDER.