US3794165A

US3794165A - Motion control for a material separator

Info

Publication number: US3794165A
Application number: US00125274A
Authority: US
Inventors: L Riesbeck; W Blackwell
Original assignee: MIDWESTERN IND Inc
Current assignee: MIDWESTERN IND Inc
Priority date: 1971-03-17
Filing date: 1971-03-17
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: AU3921172A; DE2206269A1; GB1355006A; AU471327B2; CA963431A; DE2206269C3; DE2206269B2

Abstract

A device for generating motion to a conventional material separator consists generally of a variable speed rotatable shaftlike member. Attached to the rotatable member are weights, the position of which is adjustable axially along and circumferentially around the rotatable member. Further, the axial position of the rotatable member and the weights affixed thereto is adjustable, thus providing a wide range of motions to the material separator.

Description

United States Patent [191 Riesbeck et al.

[ 1 Feb. 26, 1974 MOTION CONTROL FOR A MATERIAL SEPARATOR Inventors: Laverne J. Riesbeck; Willis A.

Blackwell, both of Canton, Ohio Midwestern Industries, Inc., Massillon, Ohio Filed: Mar. 17, 1971 Appl. No.: 125,274

Assignee:

References Cited UNITED STATES PATENTS Brautingman 74/87 X 1,394,631 10/1921 Luscana 248/23 1,995,435 3/1935 Ovenstrom... 209/366.5 X

1,380,347 6/1921 Blume 248/23 2,284,671 6/1942 Menzer 209/332 X 2,374,451 4/1945 Norvell 209/366.5

2,312,477 3/1943 Pollitz 209/329 2,697,357 12/1954 Wettlaufer... 2()9/366.5 X

2,902,868 9/1959 Ferrara 74/87 3,435,564 4/1969 Balz 74/87 X FOREIGN PATENTS OR APPLlCATlONS 1,184,191 12/1964 Germany 209/366.5

Primary ExaminerRobert Halper Attorney, Agent, or FirmHamilton, Renner &

Kenner 5 7] ABSTRACT A device for generating motion to a conventional material separator consists generally of a variable speed rotatable shaft-like member. Attached to the rotatable member are weights, the position of which is adjustable axially along and circumferentially around the rotatable member. Further, the axial position of the rotatable member and the weights affixed thereto is adjustable, thus providing a wide range of motions to the material separator.

11 Claims, 15 Drawing Figures a4 1 lrm rr"n Q 1 58 5o 49 H: so\

'PAIENTED 5.794.165

SHEET 1 0F 5 V I N VENTORS LAVERNE J. RIESBECK LIS A. BLACKWELL ATTORNEYS PATENTEDFEBZB I974 SHEET 2 0F 5 INVENTORS LA VEgNE J. RIESBiCK WLLI .BLA KW LL BY 7 W? I ATTORNEYS PATENTEDFEBZEIBH 3,794,165

v sum 3 or 5 I INVENTORS LAVERNE J. RIESBECK BY ILL I5 A. BL CK ELL 86A TM ATTORNEYS PAramgnrsszsmn saw u of 5 I INVENTORS LAVERNE J. RIESBECK WILL IS A. BLACKWELL ATTORNEYS MOTION CONTROL FOR A MATERIAL SEPARATOR BACKGROUND OF THE INVENTION This invention relates to an apparatus for generating motion in a conventional material separator. More specifically, this invention relates to an apparatus which is capable of producing and controlling a variety of motions so that a material separator can be universally utilized to classify materials having a diversity of specifications.

Many industries utilize material separators to classify certain solid materials by size or to separate solid material from liquid material. In either case, the material is fed to at least one screen surface which retains the oversize particles and allows the smaller particles or the liquid to pass therethrough. A vibrating, shaking or agitating motion is imparted to the screen to effect a more efficient separation and to move the oversize particles on the screen to a discharge area or chute generally located at the periphery of the screen but sometimes b cated centrally thereof. The type of motion to be imparted to the screen or screens varies dependent on the particular material being separated. Prior to this time, there is no device, of which we are aware, which is capable of providing the necessary range of motions so that a single material separating machine could be universally utilized for all materials.

One prior art device was first described in U.S. Pat. No. 2,284,671 and has since been shown environmentally in a number of patents pertaining to the material separating art. In this design a motor having eccentric weights on its rotating shaft vibrates the material separator which is supported by a plurality of springs. Such design, however, even as improved through the years, has presented certain mechanical as well as control problems. Mechanically, heat buildups in the area of the motor, in addition to a generally complex design, cause a rapid wearing of vital components. Further, no means have ever been provided in these devices to prevent the vibrations from loosening the electrical wires which provide the power to the motor.

In the control sense, the device of U.S. Pat. No. 2,284,671 has not proven acceptable for universal applications, particularly in that the flow pattern of the material cannot be totally adjusted. Initially, any adjusting that can be made requires substantial disassembling of the apparatus and thus cannot be made while the machine is operating. Further, the use of eccentric weights inherently initiates a force which is too vertically oriented such that certain desired flow patterns cannot be obtained. Likewise, undesirable flow patterns or even no flow whatsoever might occur if a null point existed at some height above the motor, that is, at the level of one of the stacked screens. Since this device provides no means for readily adjusting the vertical height of the forces, these null points might exist. While some of the above problems could be solved if the rpm of the motor were adjustable, such controllability is not provided in the device of U.S. Pat. No. 2,284,671. Since this machine is not capable of operation at high speeds (basically due to the fact the mechanical problems previously discussed would be compounded), those applications requiring a greater speed are either inefficiently attempted on such a machine or are not accomplished at all.

Another prior art device, designed to solve some of the above noted problems, is that shown in U.S. Pat. No. 3,273,409. This device utilizes two shafts, one stationary connected to the material separator and the other rotatable about the first and being movable laterally of the axis of the first shaft to adjust the eccentricity. Counterweights are necessary to prevent vibratory force transmission to the rotatable shaft, or stated another way, are necessary to overpower the severe unbalance created by the eccentricity. While the facet of adjusting the eccentricity of the shafts does aid in solving some of the control problems present in the prior art device previously described, certain mechanical and control problems nevertheless exist in the device of U.S. Pat. No. 3,273,409. For example, because of the eccentric shafts, severe bearing problems as well as lubrication problems exist in the device. When the bearings or any particular part must be repaired or replaced, the whole generator must be torn down and because the stationary shaft is welded to the lower portion of the material separator, the machine itself must be dismantled and certain parts thereof replaced.

The motion generated by the device of U.S. Pat. No. 3,273,409 is characterized by an excessive horizontal force and deficient vertical force. Thus, the apparatus will adequately separate liquids from solids (which pro- 'cess requires a substantial horizontal force) but does less than an efficient job on the classification of dry materials due to its inability to establish any flow pattern. Further, as is characteristic of other prior art, undesirable null points will tend to exist at certain screen levels despite efforts to eliminate the same.

SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a device for generating motion to a maprove a device, as above which is capable of adjusting the vertical height of the forces generated on particles to be separated, controlling the amount and speed of circumferential travel thereof, and eliminating null points which might exist at a particular screen.

It is yet another object of the present invention to provide a device, as above, which can be maintained, controlled and repaired without dismantling.

It is a further object of the present invention to provide a device, asabove, which eliminates the problems with bearings, heat build-ups, rapid wearing or parts and lubrication characteristic of the prior art.

It is a still further object of the present invention to provide a device, as above, which is electrically operated but not plagued with the occurrence of broken electrical connections.

These and other objects of the present invention which will become apparent from the following description are accomplished by apparatus hereinafter described and claimed.

In general, a rotatable member carries two balance trays or cages which are axially separated and which hold circumferentially adjustable weights. In one embodiment, the rotatable member is a shaft rotated by a variable speed motor; in another embodiment, the rotatable member is the motor itself. The entire assembly of the rotatable member and upper and lower weights is axially adjustable with respect to the material separator.

The multiple adjustment features, that is, adjustment in height of the motor, adjustment in speed of the motor, adjustment in circumferential position of the weights in the balance cages, and the adjustment in the amount of weights provide an unlimited variety of separator motions so that a single material separator can be utilized for the processing of any material in any given situation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a material separator which forms the environment for the motion generating device according to the concept of the present invention.

FIG. 2 is a sectional view of the motion generating device according to the concept of the present invention.

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken substantially along line 44 of FIG. 2.

FIG. 5 is an enlarged sectional view of a portion of the lower balance cage shown in FIG. 4.

FIG. 6 is a sectional view substantially similar to FIG. 2 showing an alternate embodiment of the motion generating device according to the concept of the present invention.

FIGS. 7-10 are diagrammatical plan views of a screen showing the flow patterns of a material thereon obtained through an adjustment of the motion generating device according to the concept of the present invention.

FIGS. 11-15 are diagrammatical views of a particle of material as it travels across the screen, the varying patterns being obtainable through an adjustment of the motion generating device according to the concept of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A conventional material separator is indicated generally by the numeral in FIG. 1 and is shown as having a cylindrical base 21 to which is welded, at the lower end, an annular flange 22. The material separator 20 can then be attached, as by nut and bolt assemblies 23, to the floor 24 or other desirable supporting subsurface. An upper annular flange 25 is also affixed to base 21 to hold, as by nut and bolt 26, a plurality of springs 28 or other cushioning devices.

Springs 28 carry a base plate 29, being attached thereto by nut and bolt assemblies 30. As best shown in FIG. 1, plate 29 supports a series of axially adjacent cylindrical sections 31, the bottom section being affixed to plate 29 as by nut and bolt assembly 32. Between each section 31 is a screen mounting assembly 33 which supports a screen extending across each section 31 and which is described in detail in our US. Pat. No. 3,463,3 l 5 to which reference is made for such details as may be necessary to understand the subject invention. A cover 34, placed on the top section 31, has an opening for the introduction of the material to be separated through piping 35. Each section 31 is also provided, at some point along the periphery of the screen, with a chute 36 for the discharge of the classified material. Bottom section 31 can be provided with an angularly oriented base 38 which directs all the material presented thereto to its discharge chute 36.

Extending downward and radially inward from base plate 29 are a series of reinforcing ribs 39 which support a cylindrical motion generator housing 40. Openings 41 in housing 40 allow facile access to the motor or motion generating device indicated generally by the numeral 42.

The motion generator 42 is preferably a variable speed motor and can be called an inverted motor, that is, having a fixed shaft 43 around which rotates the body portion 44 on suitable bearing members. Shaft 43 conveniently and safely contains the electrical wires 45 extending from power source 46 (which includes means to vary the speed of the motor) and is fixed to an upper support plate 48 and lower support plate 49 by set screws 50.

Plates

48 and 49 combine with cylindrical housing 40 to enclose motion generator 42 and protect it from any foreign substances.

The vertical position of the motion generator 42 is adjustable in two manners. A gross adjustment lies in the connection between the upper support plate 48 and the base plate 29 as well as the connection between the lower support plate 49 and the motor housing 40. Support plate 48 is connected to base plate 29 as by the nut and bolt assemblies 51. As shown in FIG. 2, a plurality of spacers 52 can be provided between

plates

29 and 48, the number dependent on the vertical height de sired. If it were desired to. lower the generator 42, the required number of spacers 52 could be removed and placed between the lower support plate 49 and the annular flange 53 weldedto housing 40 and attached to plate 49 by nut and bolt assemblies 54.

A second or fine vertical adjustment means is indicated generally by the numeral 55 in FIG. 2 and consists of a spider-like member 56 attached, as at 58, to the lower plate 49. A collar member 59 is fixed to the shaft 43 and receives a threaded shaft 60. Shaft 60 extends through the base of spider 56 and is rotated via handle 61. After loosening set screws 50, rotation of handle 61 easily raises or lowers the generator 42 from its uppermost position within housing 40 as shown in FIG. 2 to a fully down position or any precise location therebetween. The effect of the vertical position of the motor on the separating process will be hereinafter discussed.

Indicated generally by the numeral in FIG. 2, and shown in more detail in FIG. 3, is an upper weight tray or cage which consists of a body portion 71 which adjustably engages the member 44 at any desired point along the axial length thereof, being fixed thereto by set screws 72; an annular shelf portion 73 which is substantially perpendicular to the body portion 44 of motion generator 42; and an annular lip portion 74 defining the outside periphery of tray 70. A plurality of circumferentially spaced weight positioning pegs 75 can be molded into shelf 73, 13 such pegs being shown in FIG. 3 spaced 15 degrees apart.

A plurality of weights 76, as shown in FIG. 3 as having a shape which conforms to the sector of an annulus, have a recess 78 for receiving the pegs 75. The weights 76 may be positioned on alternate pegs 75 in any desired position, the importance of which will be hereinafter discussed.

A lower weight tray or cage is indicated generally by the numeral 80 in FIG. 1 and shown in detail in FIG. 4. Like tray 70, it consists of a body portion 81 which engages the member 44 being fixed thereto by set screws 82; an annular shelf portion 83 which is substantially perpendicular to the body portion 44 of motion generator 42; and an annular lip portion 84 defining the outside periphery of tray 80. A plurality of circumferentially spaced weight positioning pegs 85 can be molded into shelf 83, 13 such pegs being shown in FIG. 4 spaced degrees apart.

A desired number of weights 86 interchangeably similar to weights 76 may be positioned as desired on shelf 83. The recess 88 in weights 86 is provided for engaging the pegs 85. The significance of the number and position of weights 86, and their relationship to weights 76 will be hereinafter discussed. It should be evident that these weights are readily accessible and thus the addition, removal or change in position of weights becomes a relatively simple matter. While an open tray has been shown, a more fully enclosed tray or cage could be utilized. This would, of course, detract somewhat from the advantage of accessibility just described.

An alternate embodiment of the present invention, indicated generally by the numeral 100 in FIG. 6, is substantially similar to that just described. In this instance, however, the inverted motor 42 is not utilized. Rather, a variable speed electric motor 101, having a means for conveniently adjusting the speed as by handle 102, drives a shaft 103 which-supports, at its outer end, the pulley structure 104. A belt 105 transfers the rotation of pulley 104 to pulley 106 which is mounted to shaft 107. Thus, shaft 107 rotates at the speed of motor 101 as set by handle 102.

Keyed, as at 108, to shaft 107 are upper and lower mounting collars 109 and 110, respectively, each having two sets of recesses such as 111 and 112 for the upper collar 109 and recesses 113 and 114 for the lower colar 110. These recesses provide two locations on each collar for the mounting of upper and lower weight cages substantially similar to cages 70 and .80 previously described.

Since in the motion generator 100 a rotatable shaft extends through upper support plate 48 and lower support plate 49, suitable bearings 115 must be provided, held within bearing housings 116 by set screws 118. The bearing housings 116 can be integral with the support plate, as shown with respect to upper support plate 48, or can be a separate housing and attached to the support plate, as by bolts 119 attaching housing 116 to lower support plate 49. Shaft 107 is held axially in place by nuts 120.

In almost all otqher aspects, the motion generating device 100 is similar to motion generator 42. Both are provided with the

cages

70 and 80 and the adjustable weights therein; the axial position of the cages is adjustable; and the speed of revolution of the housing 44 and shaft 107 is adjustable. Further, both embodiments have means to raise or lower the entire motion generating device with respect to the material separator. While the device of FIG. 6 is not shown with the fine adjustment 55 shown in FIG. 2, it is evident to one skilled in the art that such could be provided.

Combinations of the various weight positions as well as the amount of the weights, speed of the motor, and axial position of the motion generator provide a virtually infinite number of obtainable patterns of material on the screen cloth. Only some of the basic motions obtained from the various adjustments will be described herein, it being evident that the adjustments may be combined to achieve particular screening patterns desirable, dependent on the characteristics of the specific material being screened.

The weights 76 in the upper cage generate a horizontal force on the material'separator because of its operation in a plane close to the center of the mass of the machine. By increasing the amount of each weight or the number of weights, more horizontal or radial force will be created causing oversize particles to discharge through chutes 36 at a much faster rate.

The weight 86 in the lower cage provides a vertical component of force or a tilting motion to the material separator due to its operation well below the center of mass of the machine. Increasing the distance between the weight 86 and weights 76 will, of course, lengthen the fulcrum and thereby effect the tilting motion. By increasing the amount of the weight 86 the vertical force is increased, thereby presenting the material to the screen many times prior to its discharge through chutes 36. Such vertical motion is highly desirable in heavy, coarse, or wet materials.

A tangential force component is introduced to themachine by adjusting the relative angular positions of weight or weights 86 with respect to weights 76. FIGS. 7-10, inclusive, show various flow patterns evolved when a weight 86 is set to lead the weights 76 by a certain angular degree. For example, with the weights 76 as shown in FIG. 3 and the weight 86A as shown in FIG. 4, that is, at zero degrees (in phase), the expected material travel would be directly radially outward as shown in FIG. 7. This type of pattern does not allow the material to remain on the screen for any substantial length of time and would therefore be effective only for high tonnage rough screening applications.

FIG. 8 displays a typical flow pattern when the weight 86 is set to lead the weights 76 by about 15 degrees, the weight 86 being positioned on the peg adjacent that which weight 86A is on in FIG. 4. A slight spiral effect is achieved by the induced tangential component force. FIG. 9 is the pattern achieved at a 35 degree setting which affords a veryefficient screening of average dry materials. As the lead angle increases, the flow patterns created are found continuously better in wet material applications. At the degree setting shown by the weight 86B in FIG. 4, oversize material actually is kept from leaving the screening surface as shown in FIG. 10.

It would be evident that the lead angles are adjustable either by changing the position of the lower weight or weights 86, or by changing the position of the upper weights 76, or both. It is the relative lead angle of the lower weights to the upper weights which allows one to obtain the various patterns of FIGS. 7-10, inclusive.

Whatever the pattern, the rate of travel on the screen can be additionally controlled by regulating the speed of the motor. Thus, if it is desired to achieve the pattern of FIG. 9 but have the particles travel their spiral path quite quickly, the speed of the motor could be increased. Similarly, if it is desired to direct the material slowly but directly radially outward, then a FIG. 7 configuration with a slow motor rpm would be utilized. In short, innumerable combinations of patterns and speed could be accomplished.

The present device is also capable of regulating the particle movement as it moves along the paths shown in FIGS. 7-10, inclusive. Various particle movements are shown in FIGS. 11-15, inclusive, most of which can be accomplished for any of the patterns shown in FIGS. 7-10. In FIGS. 11-15, it is to be generally understood that the right hand side of each represents the approximate center of a screen with overall particle movement being to the left, representative of moving generally radially outward toward a discharge chute. The elliptical shapes represent the orbit of a plurality of particles on a screen at a single instant in time. Thus, in effect, the particles move across the screen in a wave-like fashion.

The generally flat elliptical pattern shown in FIG. 11 can be obtained by adding more weight in the top cage 70 or, more importantly, raising the entire motion generator through the removal of selective spacers 52 or the rotation of handle 61. This particle orbit would be most advantageously used with weight 86 set at a low lead angle, such as shown in FIGS. 7-9, inclusive.

As the motor would be progressively lowered and/or weight removed from the upper cage 70 and added to the lower cage 80, the orbits of FIGS. 12-15, inclusive, could be obtained. For example, the elliptical path shown in FIG. 13 would find the motor near the center of its permissible range of vertical or axial movement. The orbit of FIG. 14 is highly influenced by vertical forces with the motor being low and possibly with additional weight in cage 80. This would be used in wet applications where the materials being separated are quite cohesive, and with lead angles of weight 86 in the range of 60.

To achieve the orbit shown in FIG. 15, the motor would be at its lowest extent and most likely additional weight would be added to cage 80. With the motor situated in such a low position, it has been found that the normally radially outward tendency of the particles is actually opposed so that the oversize particles will actually remain on the screen. Thus, these settings are to be utilized with patterns such as that shown in FIG. 10.

The vertical adjustability of the device described herein has other advantageous effects. For example, often the same motion generator is utilized to operate with a varying number of screening sections 31. A machine having two sections 31, for instance, might be properly tuned" at one particular vertical location of the motion generator. Adding two more sections 31 would further compress springs 28, thereby lowering the center of gravity of the machine and possibly creating a null point at some screen level. In this instance then, the motion generator would be lowered until efficient separating was being effected at each screening level.

It should not be evident to one having ordinary skill in the art that the device described herein provides unlimited combinations of motion adjustments, thus substantially improving the material separating art.

We claim:

1. Apparatus for generating combinations of generally horizontal and generally vertical motions to a material separator having a substantially vertical axis comprising a variable speed motor having a rotatable external body portion and a shaft passing centrally therethrough, said body portion having a generally vertical axis and mounted generally of the material separator, said shaft being operatively connected to the material separator, first tray means mounted on said rotatable external body portion and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally horizontal motion, second tray means mounted on said rotatable external body portion beneath said first tray means and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally vertical motion and means to adjust the vertical position of said motor and said first and second tray means to regulate the amount of generally vertical motion.

2. Apparatus according to claim 1 wherein each said tray means has means to hold said weights at desired circumferential positions.

3. Apparatus according to claim 5 wherein said means to hold said weights are peg members, said weights being adapted to fit over said peg members.

4. Apparatus for generating combinations of generally horizontal and generally vertical motions to a material separator having a substantially vertical axis comprising a rotatable member having a generally vertical axis and mounted generally axially of the material separator, means to rotate said rotatable member on the axis thereof, first tray means mounted on said rotatable member and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally horizontal motion, second tray means mounted on said rotatable member beneath said first tray means and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally vertical motion, means to adjust the vertical position of said rotatable member to regulate the amount of generally vertical motion and additional means to adjustably vary the vertical position of each said tray means to said rotatable member to regulate the combinations of generally horizontal and generally vertical motions.

5. Apparatus for generating combinations of generally horizontal and generally vertical motions to a material separator having a substantially vertical axis comprising a rotatable member having a generally vertical axis and mounted generally axially of the material separator, means to rotate said rotatable member on the axis thereof, first tray means mounted on said rotatable member and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally horizontal motion, second tray means mounted on said rotatable member beneath said first tray means and adapted to hold weights thereon in circumferentially adjustable positions to generate the generally vertical motion and means to adjust the vertical position of said rotatable member and said first and second tray means to regulate the amount of generally vertical motion, said means to adjust the vertical position of said rotatable member including gross adjustment means to make large vertical adjustments and fine adjustment means to make smaller vertical adjustment, said gross adjustment means including spacer means positioned between the material separator and the apparatus for generating motion.

6. A material separator including at least one cylindrical section, a screen spanning said cylindrical section, chute means for discharging the material from said screen, a plate carrying said cylindrical section, a base, cushioning means between the base and said plate, a housing depending from said plate, a motion generator within said housing, said motion generator comprising a rotatable member including a variable speed motor having a generally vertical shaft fixed to said housing and a body portion rotatable about said shaft, said motor being mounted generally axially of said cylindrical section and said screen, first balance tray means mounted on said rotatable member, means on said first balance tray means to carry weight members thereon at circumferentially varying locations, said first balance means thereby acting upon rotation of said rotatable member to direct material generally toward said chute means, second balance tray means mounted on said rotatable member below said first balance tray means, means on said second balance tray means, to carry weight members thereon at circumferentially varyihg locations, said second balance tray means thereby acting upon rotation of said rotatable member to impart a generally vertical movement to the material as it passes over said screen, and means to regulate the amount of generally vertical movement imparted to the material by generally vertically moving said housing axially of said cylindrical section.

7. A material separator according to claim 6, said housing including a means of access to said rotatable member.

8. A material separator according to claim 6 wherein said means to generally vertically move said housing includes spacer means between said housing and said plate.

9. A material separator according to claim 6 including means to generally vertically move said rotatable member within said housing.

10. A material separator including at least one cylindrical section, a screen scanning said cylindrical section, chute means for discharging the material from said screen, a plate carrying said cylindrical section, a

base, cushioning means between said base and said plate, a housing depending from said plate, a motion generator within said housing, said motion generator comprising a rotatable member having a generally vertical axis and mounted generally axially of said cylindrical section and said screen, first balance means mounted on said rotatable member, means on said first balance tray means to carry weight members thereon at circumferentially varying locations, said first balance tray means thereby acting upon rotation of said rotatable member to direct material generally toward said chute means, second balance tray means mounted on said rotatable member below said first balance tray means, means on said second balance tray means to carry weight members thereon at circumferentially varying locations, said second balance tray means thereby acting upon rotation of said rotatable member to impart a generally vertical movement to the material as it passes over said screen, means to regulate the amount of generally vertical movement imparted to the material by generally vertically moving said housing axially of said cylindrical section, a collar fixed to said rotatable member, threaded shaft received by said collar, and spider means mounted on said housing and receiving said threaded shaft so that rotation of said threaded shaft moves said rotatable member within said housing.

11. A material separator according to claim 10 wherein said rotatable member is a generally cylindrical shaft rotatably connected to said housing and driven by a variable speed motor.

' UNIT D STATES PATENT OFFIC I CERTIFICATE 0F CORRECTION Patent No. 3,794,165. Dated Febmary 26, 1974 Laverne J'. Riesbeck et 211. Inventor(s) I It is certified that errot appears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column; 7, line after "generally" insert axially Signed and" ealedthisilQth day' of November 1974.

(SEAL) Attest:

McCOY M. iGIBSON JR. c. MARSHALL DANN I Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) I USCOMM-DC wan-p59 u.s, sovz'numzm' rimmr'zs omcs; t 930 UNITED smiths-3. PATENT OFFFKCE CERTIFICATE or CORRECTION Patent No. 3, 794,165v Dated February 26, .1974

InVen-t0r(s) Laverne J. Riesbeck and Willis A. Blackwell It is certified thaterror appears in the above-identified patent and'that said Letters Patentare hereby corrected as shown below:

Column 5', line 53, "otqher" should read "other- Column 6, line 50, "would" should read --should--. Column 7', line 52, "not" should read "now";

Column 8, line 12, "claim 5" should read --claim 2--; line 31,

"to" should read "on"; line 53, "adjustment" should read "adjustments"; line 61, "the base" should read "said'base",

Column 9-, line 5, after "balance" insert "tray-n line 10, after. "means" delete the comma line 11, "varyihg" should read; "varying", line 29, "scanning" should'read "spanning".

Column 10, line 6, after "balance" insert "tray"; line 23, after "member," insert --a- Signed and sealed this 1st day of October 1974.

(SEAL) Attest: McCOY M. GIBSON JR. 7 C. MARSHALL :DANN Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMM-DC 60376-P69 a: 1.5.5. GOVERNMENT PRINTING OFFICE: 199 o-ass-aaz.

Claims

10. A material separator including at least one cylindrical section, a screen scanning said cylindrical section, chute means for discharging the material from said screen, a plate carrying said cylindrical section, a base, cushioning means between said base and said plate, a housing depending from said plate, a motion generator within said housing, said motion generator comprising a rotatable member having a generally vertical axis and mounted generally axially of said cylindrical section and said screen, first balance means mounted on said rotatable member, means on said first balance tray means to carry weight members thereon at circumferentially varying locations, said first balance tray means thereby acting upon rotation of said rotatable member to direct material generally toward said chute means, second balance tray means mounted on said rotatable member below said first balance tray means, means on said second balance tray means to carry weight members thereon at circumferentially varying locations, said second balance tray means thereby acting upon rotation of said rotatable member to impart a generally vertical movement to the material as it passes over said screen, means to regulate the amount of generally vertical movement imparted to the material by generally vertically moving said housing axially of said cylindrical section, a collar fixed to said rotatable member, threaded shaft received by said collar, and spider means mounted on said housing and receiving said threaded shaft so that rotation of said threaded shaft moves said rotatable member within said housing.