US3040891A - Oblique vibrating screen device - Google Patents

Description

June 26, 1962 w. E. SAXE OBLIQUE VIBRATING SCREEN DEVICE 4 Sheets-Sheet 1 Filed Nov. 30, 1959 .WbLTER E 54 x15 INVENTOR q M ATTORN EY 5 June 26, 1962 w. E. SAXE OBLIQUE VIBRATING SCREEN DEVICE 4 SheetsSheet 2 Filed NOV. 30, 1959 MLTEREGAu E l N V ENTOR June 26, 1962 w. E. SAXE OBLIQUE VIBRATING SCREEN DEVICE 4 Sheets-Sheet 3 Filed NOV. 50, 1959 MLTER E 50x5 ATTORN EYS June 26, 1962 w. E. SAXE OBLIQUE VIBRA'IING SCREEN DEVICE;

4 Sheets-Sheet 4 Filed Nov. 30, 1959 INVENTO'R ATTORNEYS rates The invention relates to power operated screens and has particular reference to relatively large screens for commercial use which are vibrated in order to advance the aggregate over the screen and wherein the vibrating mechanism is adapted to impart special selected vibration characteristics to the screen so that both the screening process and the operation of advancing the screened and unscreened aggregate takes place simultaneously and as a result of application of vibration from a common source.

The application is a continuation-in-part of co-pending application Serial No. 441,490, filed July 6, 1954, now Patent No. 2,915,183.

Although attempts have been made heretofore to provide screening devices which are power operated, where attempts have been made to shake the screen by use of power, mechanisms resorted to have been extremely inadequate to meet many of the expected conditions.

Movement of vibration energy at fixed locations and in the usual relationships has not resulted in the highly effective and eflicient screening which modern demands have placed upon apparatus of this nature. Also where conventional agitation or vibration sources have been resorted to, the process has not been sufliciently continuous to accommodate aheavy demand and at the same time perform a screening operation which is sutnciently selective.

It is therefore among the objects of the invention to provide a screening device which may be incorporated in either single or multiple screens wherein the application of vibration force is in an oblique direction with respect to the position of the screen in order to give to the screen vibration components in diflerent desired directions in order to produce a variety of effects upon the screen.

Another object of the invention is to provide a new and improved vibratiing screen device wherein pairs of vibration sources are located upon opposite sides of the screen and in positions such that the full effect of eccentric weights is imparted to the screens at locations near the mid-portion but also of such character that multiple components are passed from the source of vibration to the screen in order to give to the screen a versatility of movement not heretofore found possible with conventional shaking methods.

Still another object of the invention is to provide a new and improved power operated screening device of a multiple character wherein a plurality of screens of different kinds may be stacked one above the other and given a composite vibrating motion from a common source of vibration in such fashion that heavy loads may be effectively screened and the screened aggregate passed rapidly from the loading end to the discharge end in a particularly efiective and eflicient manner.

Still another object of the invention is to provide a new and improved power actuated screening device capable of large capacity and improved selectivity, the operating parts having such a relationship to each other and to a common source of vibration that the entire device is compact, capable of being located in a relatively small space, and further being not only rugged in its structure but also relatively simple in its mode of construction and operation.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects conatent 3,949,891 Patented June 26, 1962 templated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of one form of the invention showing a horizontal screen and multiple vibration inducing elements on opposite sides operated from a common source.

FIGURE 2 is a side elevational view of the form of device illustrated in FIGURE 1.

FIGURE 3 is a side elevational view of another form of the device with portions broken away to show interior structure.

FIGURE 4 is a fragmentary cross-sectional view taken on the line 4-4 of FIGURE 3.

FIGURE 5 is an end elevational view of one side of the device taken on the line 55 of FIGURE 3.

FIGURE 6 is a transverse sectional View of one side of the device taken on the line 6-6 of FIGURE 3.

FIGURE 7 is a plan view of the device on one side of a longitudinal center line wherein the opposite side is identical and omitted in the interest of condensing the showing.

FIGURE 8 is a fragmentary cross-sectional view taken on the line 8-8 of FIGURE 3.

FIGURE 9 is a partial end elevational view taken on the line 9-9 of FIGURE 3.

FIGURE 10 is a modified plan view of one of the screen panels drawn to larger scale partially broken away in order to show supporting structure.

FIGURE 11 is a transverse sectional view taken on the line 1111 of FIGURE 10'.

FIGURE 12. is a fragmentary longitudinal sectional view taken on the line 12-12 of FIGURE 10.

FIGURE 13 is a cross-sectional view showing the drive connection between a drive shaft and one of the vibrating units.

FIGURE 14 is an elevational view of one of the eccentric weights.

FIGURE 15 is a top view of one of the weights.

In the form of invention illustrated in FIGURES 1 and 2 there is shown a single long screen 10. The screen is supported at the corners and at intermediate portions by means of a series of suspension rods 11 extending upwardly in each case to a link 12 which in turn passes through a beam support 13. At the upper end of the beam support is a spring housing 14 having a spring 15 therein. The link is attached to the spring at its upper end so that the spring acts in compression to resiliently support the respective corner or intermediate portion of the screen 10. Intermediate supports are located as frequently as need be along the length of the screen depending upon the length. It will be noted that an eyelet 16 is used in each case to connect the suspension rod 11 to the screen, the eyelet connection being similar to the connection between the suspension rod and the link 12 sufficient that there be a certain freedom of motion at all of these points.

The screen in turn comprises frame channels 17 and 18 having beams 19 at the opposite ends, one of which is shown in FIGURE 1 whereby to complete the frame construction. Screen wire 20 is stretched over the frame and secured by conventional means such as by use of clamps 20' of any suitable form. It will further be noted that the frame and screen wire thereon occupies a position in a horizontal plane.

For imparting vibration to the screen at different locations along its length in those cases where the length is excessive, there is provided a shaft or rod 21 rotatably mounted one on each side of the end of the screen by means of bearing brackets 22, 23 and 24. There is an appreciable obliqueness or slope to the mountings of the shafts 21 in each case. That is to say, the shaft is oblique relative to the horizontal position of the screen, although shafts on respectively opposite sides of the screen are parallel to each other. Vibration is produced by eccentric weights 25 at the upper ends of the respective shafts 21 and eccentric weights 26 at the lower ends of the respective shafts, non-rotatably secured thereto. Effective vibration is achieved when the weights 25 at the upper ends of the shafts have their off-center weighted portions extending in opposite directions when the weighted portions are in the same plane. To this end the weighted portions will both be directed upwardly at the same time and downwardly at the same time, thereby to act together in somewhat balanced relationship. In side positions such as that shown in FIGURE 1, they counterbalance each other so that there is no sideward thrust or vibration imparted to the screen.

To provide for rotation of the shaft 21 power is taken from a suitable source and transferred through a belt drive 27 to a pulley 28 non-rotatably mounted upon a shaft 29. The shaft in turn is rotatably mounted by means of brackets 30, 61, 32 and 33 to the frame and in particular to the cross-beam 19 shown in FIGURE 1 only. A bevel gear 34 is located at each end of the shaft 2? meshing with a similar bevel gear 35 at the upper end of each of the shafts 21. By this train of power the shafts 21 on opposite sides of the frame at the left end, as viewed in FIGURES 1 and 2, are rotated at the same rate of speed and simultaneously with respect to the eccentricity of the weights. The tilted direction of the shafts 21 effects an application of vibrational force in an oblique direction, as viewed in the figures. This tilted or oblique application of vibrating force tends not only to advance the heavier particles which do not pass through the mesh of the screen in periodic jumps from the left end of the screen toward the right end of the screen but also tends to shift the screen in a vertical direction by applica tion of the vertical component so that the finer particles simultaneously are sifted or screened through. Hence, the left end of the screen is here identified as the loading end and the discharge end will be toward the right.

To secure a continuous operation and in order to screen out all particles of various different sizes which comprise the aggregate, thereby minimizing waste dumped off the discharge end, the screen may be made virtually of any desired length, as illustrated.

To continue the application of power from the vibrating portion of the left end of the screen to the right end of the screen, a sprocket 36 is mounted at the lower end of the shaft 21 and has a chain 37 extending thereover to a sprocket 38 at the upper end of the particular shaft 21 immediately to the right of the first identified shaft 21. When the sprockets 36 and 38 are made of the same diameter and number of teeth, rotation of the shafts '21 at the left and right ends of the screen, respectively, will be at the same rate of speed and in the same rotational direction. Obviously, if the screen be extra long, it is further possible to add still a third vibrating mechanism, not shown, in exactly the same fashion as already described. The process may thus be extended to any reasonably desirable length without varying the structure from that shown and described. So long as the application of the vibrational effect is in an oblique direction, particles not screened through the mesh of the screen will continue to advance toward the right until discharged off the dis charge end of the screen.

In another form of the invention illustrated in FIG- URES 3 through 13, inclusive, the device is arranged more compactly and the application of vibration to the frame and the screen is contained between the opposite ends of the frame. In this form of the invention large capacity may be achieved by employment of two, three, or even more, if necessary, screens, one above the other, mounted upon the same frame and agitated by the same source of vibration.

In this form of device supports 40 and 41 are shown at opposite ends of a composite frame indicated generally by the reference character 42. The frame itself is constructed along substantially conventional mechanical principles and includes channels 43 extending longitudinally, one on each side, and to which are attached plates 44 which enclose the frame on each side. Columns 45 extend upwardly on the outer sides of the plates. Transverse support is provided by employment of beams 46 which extend across the middle course and similar beams 47 which extend across the upper course.

Shelf brackets 48, 49' and 50 attached to the inner sides of the plates 44 serve to support respectively a lower course screen member 51, a middle course screen member 52, and an upper course screen member 53.

The structure of the individual screen members is substantially the same for each of the lower, middle and upper courses and is shown in some detail in FIGURES 10, 11 and 12 where the screen member 53 is depicted. As shown, the screen member comprises longitudinally extending channels 54 and 55 which are tilted slightly, as shown in FIGURE 11, for convenience. The channels are connected together at opposite ends by angle sections 56 and 57, welded preferably at the junctions, as are other connections in the device. Transverse support intermediate the opposite ends is provided by 2 sections 58 where, as in the illustrated embodiment, three are sufficient, but the number will vary depending upon the length and the span. Screen wire 60 is laid over the upper flanges of the angle sections and Z sections and there fastened down by strips 61 and 62 which may, for example, be secured by rivets or spot welding.

At a loading end 63 there is provided an angle section 64 which preferably extends from one side of the frame to the other, the bracket being attached to a transverse plate 65 to provide transverse stability at the loading end. A hopper 66, likewise extending the full breadth of the loading end of the device is supported by the angle section 64 and provides means for reception of the aggregate which is to be screened. A deflector 67 assists in distributin g the aggregate upon the upper course screen member 53.

At a discharge end, indicated generally by the reference character 70, transverse support is provided at the upper portion by means of an angle section 71 which connects to the'plates 44 adjacent the columns 45. At the lower portion angle section 72 similarly interconnect the opposite plates 44. Additional transverse support is provided by tubular stringers 73 and 74 at the lowermost portion of the frame.

Further at the discharge end 72 there are provided deflectors 75-, 76 and 77, respectively, for the lower course, middle course, and upper course screen members. To assist in the discharge of the screened aggregate the upper course screen member 53, for example, is provided with a discharge lip 78 located further toward the right than a discharge lip 79 of the middle course so that the aggregate remaining on the respective screens may be directed to different locations.

It is important that the frame be mounted in a cushioned mounting upon the supports 40 and 41 in order that the screen be operated most effectively. In the chosen embodiment cushions of greater capacity are provided at the loading end than at the discharge end primarily because of the greater concentration of weight immediately at the loading end, although the character of the cushioning structure is comparable.

At the discharge end, by way of example, there is shown a spring keeper mounted upon the support 41, as shown particularly in FIGURES 3 and 9. A. similar keeper 86 is attached to a plate 87, in turn carried upon the respective channel 43. A heavy compression spring 88 is mounted in the keepers and is of suflicient capacity to carry the expected load of the frame and the material. One spring may be suflicient for each corner of the discharge end and will cushion the load of the screen in a vertical direction.

Additional transverse cushioning is provided by means of a spring 89 which is attached at one end to a plate 90 carried by the spring keeper 85 and at the other end to a bracket 91 carried by the plate 44.

The structure at the opposite end is similar except that there are provided two springs 92 and 93 at each corner which, however, are mounted in substantially the same fashion by a double spring keeper 85 on the support 40 and a second double spring keeper 86' attached to plates 87 carried upon the channel 43. At the same opposite end or loading end likewise there is provided on each side a transverse spring 94 attached at its ends by the same fastening means as described in connection with the spring 89 and illustrated in FIGURE 9.

It will be understood from the description of the cushioned support embodied in the sundry springs that the entire frame is floated upon the supports 40 and 41 in a manner such that effective cushioning is provided in all directions.

In order to provide the necessary source of vibration the screen device in the embodiment made reference to is equipped with two shafts 95 which are located on opposite sides of the frame intermediate the loading end and the discharge end. The shafts and their mounting and equipment are identical except for being reversed left for right on the opposite sides of the frame. To mount the shaft in either case there is provided a bushing 96 at the upper end and a similar bushing 97 at the lower end. As shown in FIGURE 13, the bushing 96 is bolted to a plate 98 which in turn is carried by a housing 99. A similar structure, not shown in detail, is employed at the lower end. The housing is made fast to the appropriate plate 44 by welding, if preferred, or by other conventional fastening means so that the housing 99 and the frame 42 are securely fastened together and become integral parts of the assembly.

Attention is directed to the fact that the axis of the shafts 95 is tilted at a considerable angle, somewhere between thirty and sixty degrees with relation to horizontal. Hence, by providing a vibration force in but a single direction transverse to the axis of the shaft, the force is sufficient to provide two components, namely, a vertical component and a horizontal component in the frame and consequently in the screen members so that the double effect will not only screen the aggregate through the sundry screens but also advance the coarse aggregate remaining on the screens from the loading end to the discharge end. The number of screens, the character of the aggregate, the fineness of the screens, and other factors influence the tilt provided for the shaft axis.

' The vibratory action is provided by a pair of eccentric weights 1011 and 191, one being located adjacent the upper end and a second being located adjacent the lower end. One of the weights is shown in detail in FIGURES 14 nad where, as noted, there is provided a body 102 in which is a keyway 193 for reception of an appropriate conventional key by means of which the body can be keyed t0 the shaft 95 in a particular position. A cap 194 has an inner arcuate surface 105 complementary with respect to an arcuate surface 106 in the body so that the two surround the'shaft leaving a space 107. An end piece 108 fits over the outer end of the body 102 and machine screws 109 extend through the end piece and the body into the cap 104, whereby the end piece, the body and the cap are drawn together and the cap and body are fixed to the shaft, the space 107 previously made reference to being provided so that the parts can be drawn up tightly into position. By reason of the fact that a considerable portion of the body mass is on one side of the shaft as is also the mass of the end piece 108, the weight provides an eccentric effect which, when the shaft rotates, produces the desired vibration force. If need be, the weights can be mounted in pairs as shown in FIGURE 13.

It is further important to note that the weights when mounted on the shafts are oriented in such position that when the eccentric portion of the weights on the shaft on one side of the machine extend in an innermost direction, as viewed in FIGURE 13, the weights 100 of the shaft 95 on the opposite side of the machine will likewise extend to their innermost direction. In this way, when the weights rotate, they counterbalance each other and eliminate any transverse vibrational effect, thereby confining the entire vibration force to a direction ninety degrees with respect thereto.

The housing 99 is of such construction that it provides a closed chamber 110, the outer side of which is covered with a cover 111 which may, if desired, be rubber and which can be attached thereto by means of screws 112. An annular seal 113 at each end surrounding a reduced portion 114 of the shaft is shown in FIGURE 13, there being provided an enlargrnent 115 which is rotatably mounted in the appropriate bushing 96. A tubular brace 116 extends from one housing 99 to the other at the upper end through the upper portion of the screen device, if need be, to add to the lateral stiffening effect, especially in view of the vibratory force generated within the housings 99.

As a source of rotational drive a drive shaft 117 mounting a pulley 118 of substantially conventional design is adapted to be driven by a belt drive (not shown). The drive shaft is journalled on each side in a bushing 119 carried by a casing 120 at the upper end of the housing 99. A bearing ring 121 rotatably mounts the end of the drive shaft in the bushing 119 and a seal ring 122. eflectively seals a gear chamber 123 together with the seal ring 113 so that a suitable lubricant can be contained within the casing. The chamber is closed by a cover 124 over a suitable opening 125. At the outermost ends of the drive shaft 117, one end of which is shown in FIGURE 13, there is mounted a, bevel gear 126 which meshes with a similar bevel gear 127 on the shaft 95. The gears on opposite sides of the device are arranged in such fashion that the shafts 95 are rotated in opposite directions by action of the drive shaft 117.

From the foregoing description it will be clear that the mounting of the frame cushioned as it is by the spring floats the frame for the screens and obviously the screens mounted thereon in such fashion that they can vibrate freely in any direction in which a vibration force is applied. Application of the vibration force in a direction oblique to the plane of one or more of the screens produces the components described which perform the double function, namely, that of screening the aggregate and also that of advancing the coarse aggregate confined on any one or more of the screens from the loading end to the discharge end. The degree of tilt is of course adjustable when the structure is prepared and can be varied depending upon the use to which the device is to be put. Further, the number of separate screens can be varied from one to three, as shown, or more, if need be. The upper course screen member will obviously be the coarser and the middle and lower course screen members progressively finer in most instances so as to separate aggregate out in different degrees of fineness. In this way a multiple screening result can be accomplished with a considerable degree of effectiveness and rapidity. The screen is further able to accept relatively heavy loads at the discharge end and process relatively heavy loads of the selected aggregate in a manner far more satisfactory than screens of the conventional type and especially single course screens heretofore available.

It will further be clear that the weights can be adjusted at will along the respective shafts 95 so that if a greater effect might be needed on the upper end of the assembly than the lower end of the assembly, such an effect can be accomplished by a suitable locating of the upper weight. Similarly, the lower weight can be adjusted and balanced with respect to the location of the upper weight to accommodate different types of aggregate and also to achieve varied results in the ultimate screening process.

While the invention has herein been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described the invention, what is claimed as new in support of Letters Patent is:

l. A screen device comprising a support, a substantially horizontal frame having a screen thereon, in a substantially horizontal plane, a plurality of cushion connections to the support on each side of the frame, a plurality of pairs of brackets on each side of the frame and a rod rotatably mounted on each pair of brackets in an oblique direction relative to the plane of the screen, each said rod being carried on the frame by said brackets, eccentric weights nonrotatably mounted on the rods and having the axis of rotation of the weight in each instance concentric with the axis of the rod, with said weights on rods on opposite sides of the screen being off-center in opposite directions in a plane passing through the axes of both said rods, a rotating connection between rods on the same side of the frame, a rotating source of power and a drive train from said source of power to the rods.

,2. A vibrating screen device comprising a support, a frame and resilient means at the perimeter of the frame resiliently mounting said frame on the support in a substantially horizontal position, a screen secured to the frame in a substantially horizontal plane, sets of brackets on opposite sides of the frame, shafts rotatably mounted respectively in said sets of brackets parallel to each other and in an oblique angular position relative to the plane of said screen, said shafts being carried on the screen by said brackets, eccentric weights on opposite ends of each said shaft, each weight having an axis of rotation concentric with the axis of the respective shaft, said shafts being mounted in a relationship wherein corresponding weights on opposite shafts are off-center laterally in opposite directions when in a plane passing through the axes of both said shafts, and a source of power common to said shafts having connections to the shafts adapted to simultaneously rotate said shafts in opposite directions at the same speed whereby to generate vibration components in the screen in both vertical and horizontal directions.

3. A vibrating screen device comprising a support, a frame and resilient means at the perimeter of the frame resiliently mounting said frame on the support, a plurality of screens secured to the frame in vertically spaced substantially horizontal planes, a feeding station at one end of the uppermost screen and discharge stations at ends of the screens opposite to the feeding station, shafts mounted on respectively opposite sides of the screens parallel to each other and at an angle oblique relative to the horizontal, each said shaft being carried by the frame at a location removed from said support, eccentric weights on the shafts in laterally balanced relationship when lying in a plane passing through the axes of both said shafts, a source of power and connections from the source of power to the respective shafts movable in a direction rotating said shafts in opposite directions at the same speed, whereby to vibrate said screens in a direction oblique relative to planes of said screens and generate in said screens vibration components respectively in vertical and horizontal directions.

4. A vibrating screen device comprising a support, a frame and resilient means at the perimeter of the frame resiliently mounting said frame on the support, a plurality of screens secured to the frame in vertically spaced substantially horizontal positions, a feeding station at one end of the uppermost screen and discharge stations at ends of the screens opposite to the feeding stations, a set of brackets on respectively opposite lateral sides of the frame, shafts mounted in respective sets of brackets parallel to each other and at an oblique angle relative to horizontal, said shafts being on respectively opposite lateral sides of the screens, an eccentric weight adjacent each end of each shaft, each said weight being mounted with the axis of rotation concentric with the axis of the respective shaft and being carried on the frame by the respective shaft, the uppermost weight on each shaft being located above the uppermost screen, the lowermost weight on each shaft being located adjacent the lowermost screen, said weights having eccentric portions in balanced relationship when lying in a plan passing through the axes of both said shafts, a source of power and connections from the source of power to the respective shafts movable in a direction rotating said shafts in opposite directions at the same speed, whereby to vibrate said screens in a direction oblique relative to planes of said screens and generate in said screens vibration components respectively in vertical and horizontal directions.

5. A vibrating screen device comprising a support, a frame having a screen thereon, spring mounts securing said frame and screen on said support in a substantially horizontal position with the plane of the screen extending horizontally, said spring mounts comprising vertically positioned coil springs and horizontally positioned coil springs cushioning movement of said frame in both vertical and horizontal directions, shafts mounted on respectively opposite lateral sides of the frame and the screens in a direction oblique relative to the plane of the screens, each shaft having a plurality of eccentric weights mounted with the axis of rotation concentric with the axis of the respective shaft and in positions wherein weights on opposite shafts are in laterally counterbalanced relationship when lying in a plane passing through the axes of both said shafts, said weights being carried on the frame by the respective shafts, a source of power and connections from said source of power to said shafts adapted to rotate said shafts in opposite directions and at the same speed.

References Cited in the file of this patent UNITED STATES PATENTS 2,112,886 Greenwolt Apr. 5, 1938 2,200,724 Robins May 14, 1940 2,304,573 Kessler Dec. 8, 1942 2,367,070 Symons Jan. 9, 1945 2,511,239 Behnke June 13, 1950 2,707,559 Saxe May 3, 1955 FOREIGN PATENTS 854,007 Germany Oct. 30, 1952

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