Abstract:
A vibratory plate screen having a first end for quickly mounting in a vibrator housing, an intermediate region with openings therein and a securement end that allows one to quickly secure a vibratory plate screen in a vibratory housing. In addition, the screen is sufficiently flexible to enable one to mount the vibrator screen in a curved condition or stressed condition so that the inherent tensile strength of the material assists in holding the vibratory plate screen in position. A further feature of the invention is the quick removal and securement of the vibratory plate screen.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application titled VIBRATION SCREEN SYSTEM Ser. No. 11/417,879 filed May 4, 2006 now U.S. Pat. No. 7,467,716 which claims priority from provisional patent application titled VIBRATION SCREEN SYSTEM Ser. No. 60/795,682 filed Apr. 29, 2006. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to screeners and, more specifically, to improvements to screeners and method of making and installing vibratory screens. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None 
     REFERENCE TO A MICROFICHE APPENDIX 
     None 
     BACKGROUND OF THE INVENTION 
     The use of vibrator housings where screenable material is directed onto a vibratory housing having a screen that allows the smaller screenable material to fall through the screen allows one to quickly and efficiently separate smaller size material from larger size material is known in the art. Typically, a mesh screen is mounted in the housing with the side edges of the mesh screen folded over so that a clamp can secure the side edges of the screen to the sides of the vibratory housing. One of the disadvantages of such vibrator screens is that it is time consuming to change the screen when the screen wears out. Another disadvantage is that such units are prone to retaining material thereon a problem if the material is food or other organic material. Another difficulty is that the screens that are used have a woven pattern and provide high points that can wear quickly thus requiring the screen to be replaced frequently. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention comprises a vibratory plate screen having a first end for quickly mounting in a vibrator housing, an intermediate region with openings therein and a securement end that allows one to quickly secure the vibratory plate screen in a vibratory housing. In addition, the screen can be sufficiently elastic to enable one to mount the vibratory screen in a curved condition or stressed condition so that the inherent modulus of elasticity of the material is sufficient to assist in holding the vibratory plate screen in position. A further feature of the invention is the quick removal and securement of the vibratory plate screen. Other features of the invention are described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a system for vibratory separation of materials; 
         FIG. 2  is a top view of the system of  FIG. 1 ; 
         FIG. 3  is an isolated perspective view of a vibratory housing of  FIG. 1 ; 
         FIG. 3A  is a partial view showing the fastener relationship ship for a vibratory screen; 
         FIG. 4  is an isolated view of the vibratory housing of  FIG. 3  with the top member removed; 
         FIG. 5  is an end view of the vibratory housing of  FIG. 3 ; 
         FIG. 6  is a top view of a vibratory screen; 
         FIG. 6A  is a side view of the vibratory screen of  FIG. 6 ; 
         FIG. 7  is a partial top view of the vibratory screen; 
         FIG. 8  is a top view of the vibratory screen housing without a vibratory screen therein; 
         FIG. 9  is a partial view of a vibratory screen and a side rail; 
         FIG. 10  is a sectional view of the vibratory screen housing taken along lines  10 - 10  of  FIG. 8 ; 
         FIG. 10A  is a detail showing the insertion of an end of a vibratory plate screen beneath a rail; and 
         FIG. 10B  is a detail view showing the end of the vibratory plate screen positioned in the installed condition; 
         FIG. 11  is an isolated side view of the rail of  FIG. 10 ; and 
         FIG. 11A  is an isolated top view of the rail of  FIG. 10 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is a perspective view of a system  10  for vibratory separating materials of different sizes and  FIG. 2  is a top view of system  10 . System  10  includes a stand  12  for supporting a hopper  11  for receiving the material to be separated and a vibratory screener  14  that is supported from stand  12  by a set of four cables and springs  16  that permit vibration of vibratory screener  14  while maintaining the vibratory screener  14  in a position to continually receive material from hopper  11 . A vibratory motor  15  is mounted on top of vibratory screen  14  to provide the necessary vibration forces to vibratory screener  14 . 
       FIG. 3  shows an isolated perspective view of the vibratory screener  14  and  FIG. 5  shows an end view of the vibratory screener  14  with the vibratory screener having a housing  21  comprising a trough or channel like shape and a top member  22  with the top member secured to housing  21  by bolts or the like to form an elongated channel  25  for dispensing materials there through. Located on top of member  22  is a conventional vibratory motor  15  powered from a source (not shown).Vibratory motors typically comprise a motor and a shaft with offset weights on the end of the shaft so that rotation of the shaft produces vibration. 
     Located in one end of top member  22  is an inlet  23  that allows material from hopper  11  to fall under the influence of gravity onto a receiving region in vibratory plate screen  30 . The receiving region  30   d  is shown in  FIG. 6  and generally comprises a region that is void of screen openings and preferably extends a distance x so that as the material falls on to the screen from the hopper  11  it does not fall directly onto the screen openings, which could cause material compacting in the openings. However, if material compacting is not a problem in the delivery of materials to the vibratory screener  14  the receiving region could also contain screen openings. 
     Located on the opposite end of vibratory screener  14  is an outlet  24  for unscreened material and located at the bottom of vibratory screener  14  is an outlet  39  for material that has been screened by virtue of having fallen through a set of screen openings  30   e  in vibratory plate screen  30 . 
       FIG. 4  shows an isolated view of vibratory screener  14  with the top member  22  removed in order to show the vibratory plate screen  30  mounted in an operational mode.  FIG. 6  shows an isolated top view of the vibratory plate screen  30  which is mounted in housing  21 . 
       FIG. 6  shows a vibratory plate screen  30  comprising a metal plate having a top wear surface  30   a , a first end  30   b  for restraining in one end of housing  21 , a second end  30   c  for fixedly securing to the opposite end of housing  21  and an intermediate section therebetween including a receiving region  30   d  and a set of openings  30   e  therein for screening material there through. A set of holes  30   g  allows for insertion of a stud bolt or the like there through to allow vibratory screen  30  to be fixedly mounted in vibratory screener  14 . 
       FIG. 7  shows an alternate embodiment of a portion of a plate screen  33  that includes a set of openings  33   b  with the openings  33   a  extending to the edge of the plate screen. By having the openings extend to the edge of the plate screen  33  it ensures that materials will not flow along the sides of the screen and thus avoid the screening process. 
       FIG. 3A  shows an isolated view of a portion of the vibratory plate screen  30  to show a stud bolt  35  extending through screen opening  30   g  in screen second end  30   c  to fixedly hold the vibratory screen  30  in housing  21 . In operation the operator secures stud bolt to member  37  to hold the end of vibratory screen  30  in position. Although a stud bolt is shown other means of fixedly fastening the vibratory plate screen can be used. 
     In the embodiment shown in  FIG. 4  the first end  30   b  is restrained in vibrator housing  21  through coaction of a set of rails and the sidewalls  21   a  and  21   b  of housing  21 .  FIG. 4  shows the housing sidewalls  21   a  and  21   b  and one rail  29 . Rail  29  comprises a cross rail that extends from side to side of housing  21  to restrain vibratory plate screen end  30   b  from vertical displacement. The second end  30   c  of vibratory plate screen  30  is fixedly secured to a cross member  37  (see  FIG. 4 ) by stud bolts  35 . 
     To illustrate the underside peripheral rail support for vibratory plate screen  14  reference should be made to  FIGS. 8  to  FIG. 10B .  FIG. 8  shows a top view of vibratory screen housing  21  without the top member  22  and without the vibratory plate screen  30 . Located along side  21   a  of housing  21  is a curved side rail  40  and located along the opposite side  21   b  of housing  21  is a second curved side rail  41 . Rail  40  and  41  extend along the sides of housing  21  and are fixedly secured thereto to become side peripheral rail supports for the under side of vibratory plate screen  30 . The top cross rail  29  which extends along the end of housing  21  and side rails  40  and  41  comprise a set of rails for restraining vibratory plate screen  30 . To fixedly secure the end  30   c  of vibratory plate screen  30  housing  21  includes a cross member  37  having threaded openings  37   a  therein for receiving a stud bolt or the like. 
       FIG. 10  shows a sectional view taken along lines  10 - 10  if  FIG. 8  to show support rail  40  secured to housing  21  with the rail  40  having a top rail support surface  40   b  with a set of recesses  40   a  therein. Rail  40  provides peripheral side support for one side of vibratory screen  30 . Similarly, the rail  41 , which is secured to the opposite side of housing  21 , provides a peripheral side support for the opposite side of vibratory screen  30 .  FIG. 11  shows an isolated side view of rail  40  showing that rail  40  is provided with a curvature R and a top surface  40   b  with a set of recess  40   a  located along at least a portion of the top surface. Similarly,  FIG. 11A  shows an isolated top view of rail  40  which has a planer side  40   c  for securement to the inside side of the vibratory n housing  21  as shown in  FIG. 10 . As the rail  41  for the opposite side of housing  21  is identical it is not shown in detail. 
       FIG. 9  shows the positioning of the rail recess  40   a  with respect to openings  30   e  in the vibratory screen  30  in a position that inhibits material from adhering to the vibrator housing  21 . In the embodiment shown the recess  40   a  on the rails are aligned with openings  30   e  in the screen so that material that falls through screen  30  will have a passageway to the discharge chute  39 . The support for vibratory plate screen  30  allows vibratory plate screen  30  to be made with openings that extend from side to side of the vibratory plate screen  30 . 
     One of the features of the invention is the quick mounting of the vibratory plate screen  30 . Since vibratory screens are subject to wear as the materials are vibrated thereon the vibratory screens needs to be replaced from time to time. In the present invention one can quickly remove an old vibratory screen and replace it with a new vibratory screen.  FIG. 10A  shows how end  30   b  of vibratory plate screen  30  is inserted or slid beneath a top cross rail  29  that extends from side to side of housing  21  while using the side rails  40  and  41  as guides. 
       FIG. 10B  shows the end  30   b  of vibratory plate screen  30  supported vertically by rail  40  and top rail  29 . While the end  30   b  can be slid in or out of the spacing between rails  29   a the screen  30  is restrained from lateral movement by the sides of housing  21  and from vertical movement by the rail  29 . 
     A further feature of the invention is the rail support of vibratory plate screen  30  that allows removable fasteners on end  30   c  to secure the vibratory plate screen in fixed position during vibratory screener. The rails allow for removal and replacement of the vibratory plate screen  30  through the open end or outlet  24  of housing  21 . That is, the stud bolts  35  are located at a discharge outlet  24  and are accessible to an operator. Once the stud bolts  35  are removed one can slide the vibratory plate screen  30  out of the housing  21  since the set of rails do not longitudinally restrain vibratory plate screen therein. 
     A further feature of the invention is the stress mounting of the vibratory plate screen  30  to ensure that the vibratory plate screen dynamically moves back and forth with the vibrations induced in the vibratory housing  21 . 
     A reference to  FIG. 10  shows a curvature R to the rail  40  and a reference to  FIG. 6A  shows a side view of vibratory plate screen  30  in a planar or flat condition with essentially an infinite radius of curvature. Thus there exists a difference in the radius of curvature of the side rail supports and the vibratory plate screen  30 . In the stress installation mounting of the end  30   b  of vibratory plate screen  30 , which has a first radius of curvature that is different from the radius of curvature of the rails, the end  30   b  is inserted beneath rails  29  as shown in  FIG. 10A . Next, the operator grasps the end  30   c  of vibratory plate screen  30  and with a downward force on the topside of vibratory screen  30  forces screen  30  against cross member  37  (see  FIG. 8 ) bringing the radius of curvature of the vibratory plate substantially equal to the radius of curvature of the side rails. This produces stress in vibratory plate screen causing the cross rail  29  and the side rails to vertical restrain the vibratory plate screen. Once in the stress mounting position the side rails  40  and  41  provide vertical peripheral side support and the sides of housing  21  namely,  21   a  and  21   b  can assist in laterally restraining screen  30 . When the vibratory screen  30  is in forced to conform to the curvature of side rails  40  and  41  the stud bolts  35  are inserted through openings  30   g  (see  FIG. 6 ) and into the member  37   a  (see  FIG. 8 ) to secure the vibratory plate screen  30  in a flexed or curved condition in housing  21 . 
     While a stress mounting of the vibratory plate screen  30  has been shown it should be understood that the vibratory plate screen could also be secured without stress mounting. 
     Thus with the use of removable fasteners on only one end of the vibratory screen  30  the vibratory screen can be brought into a fixed support in housing  21 . That is, as the vibratory screen is subject to vibration and shaking it is necessary to hold the screen firmly in position in the housing. By use of a rail on one end and on the sides, which combined with the stress, mounting of the screen  30  allows the screen  30  to be firmly held in position by fasteners located only at the discharge end of the screen  30 . 
     Once the screen is in position the vibratory motor  15  shakes or vibrates the vibratory screener  14  thus causing materials to flow along the vibrator  25  in the vibratory screener  14  with the smaller sized materials falling through screen  30  and the larger materials flowing along the screen  30  and discharge from the outlet  24 . 
     Thus the invention includes a two phase method of mounting a vibratory plate screen in a vibratory housing comprising the steps of slideably positioning a first end  30   b  of the vibratory plate screen  30  into engagement with a set of rails  29 ,  40  and  41  on the vibratory screener housing  21 ; and fixedly securing a second end  30   c  of the vibratory plate screen  30  to the vibratory screen housing  21 . In addition by applying a face force i.e. a force perpendicular to the second end  30   c  of the vibratory plate screen while restraining the first end  30   a  with the set of rails one can bring the second end into a securable position. 
     To provide for ease installing the vibratory plate screen the step of restraining the first end includes inserting the first end beneath an end rail  29  which is spaced sufficiently far apart from the side rails  40  and  41  so as to form a snug but non-interference fit there between. 
     Thus in one embodiment the vibratory plate screen comprises a plate having a top wear surface  30   a , a first end  30   b , a second end  30   c  and an intermediate region with openings  30   e  therein for screening material therethrough with the first end  30   b  slideably engageable with a vibratory housing rail  29  and the second end  30   c  fixedly securable to a vibrator housing  21  to thereby secure the vibratory plate screen  30  in an operational mode. By forming the screen from a flat metal plate the vibratory plate screen can include a top surface  30   a  of the vibratory plate screen which lies in a single plane with the vibratory plate screen free of protrusions. Thus, the vibratory plate screen has a first radius of curvature but is sufficiently flexible so as to flex into a second radius of curvature when secured to a vibratory housing.