Abstract:
A material sorter using guide rails of various configurations on an inclined panel to assist in sorting mixed density materials into higher density and lower density piles. In some embodiments, the guide rails may be repositioned via actuators or manually to adapt to requirements for different types of mixed-density materials to be sorted. The guide rails may be fixed in various discrete positions. Combinations of diverging and converging guide rails are used in some embodiments. Arrangements of multiple material sorters, each configured for different types of mixed-density materials, are disclosed.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application Ser. No. 61/526,261 filed Aug. 22, 2011 by the same inventor. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to material sorters, and more particularly relates to an apparatus for sorting mixed-density materials. 
     BACKGROUND 
     In pursuit of a green economy, progressively more intensive recycling efforts are being undertaken. In separating construction debris to obtain cardboard from a debris mixture including wood and cardboard, for example, hand-sorting operations are required that can consume four hours per truckload of mixed-density material. The sorting is required because the machinery used to recycle cardboard is susceptible to damage from wood. Similar sorting problems arise with other types of mixed-density materials. 
     The present inventor, who has significant experience in material sorting, began work on developing a solution for speeding up the sorting process in February of 2009. What follows is the result of his efforts. 
     Accordingly, it is desirable to speed up the separation of mixed density materials. In addition, it is desirable to speed up any separation operation that involves separating a denser material from a less dense material. In addition, it is desirable to provide an apparatus for those purposes. In addition, it is desirable to have the apparatus be of economical design and easy to operate. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     The present invention has been tested and shown to reduce sorting time to about twenty minutes per truckload of mixed-density material. This reduction by a factor of more than ten is worth tens of millions of dollars annually to large processors of mixed-density material. The cost of applicant&#39;s invention is trivial compared to the cost of conveyor sorters. The floor space taken up by applicant&#39;s invention is trivial compared to the floor space taken up by conveyor sorters. 
     BRIEF SUMMARY 
     An apparatus is provided for assisting in sorting of dry mixed-density material into more dense and less dense piles. One of embodiment of the apparatus comprises a inclined panel having converging and diverging guide rail pairs in which mixed-density material is deposited at the top to the incline and then slides down the incline, impacting the guide rails during descent. The less dense material is slowed and directed in its descent by contact with the guide rails to a greater extent than the more dense material, resulting in separation of the more and less dense materials. In an embodiment in which the top guide rails are converging and the lower guide rails are diverging, the more dense material tends to be dropped at the bottom of the incline directly below the point at which the debris was deposited, and the lighter material, being more susceptible to the force of the diverging guide rails is dropped to the sides. The apparatus has specific applicability to sorting cardboard from wood in construction debris and general applicability to sorting other combinations of materials of significantly different densities. 
     A method is provided for sorting mixed-density material including the steps of providing the apparatus, depositing the mixed-density material at the top of the incline, and collecting the at least partially separated materials at the bottom of the incline. 
     A material sorter including: a rigid inclined panel having a top surface, a top portion of the top surface, and an inclined centerline; a guide rail abutting the top surface and coupled to the rigid inclined panel at an angle to the center line that is not parallel to the center line; and where a load of mixed-density material dumped on the top portion of the inclined plane will move downward to at least partially impact the guide rail, thereby changing a first downward path of lower density material of such mixed-density material differently than a second downward path of higher-density material of such mixed-density material, to assist in sorting the load of mixed-density material. The material sorter, where the guide rail includes a rotationally coupled guide rail, able to rotate slidingly on the top surface of the rigid inclined panel. The material sorter, further including a first actuator able to rotate the rotationally coupled guide rail. The material sorter, where the rotationally coupled guide rail and the rigid inclined panel are configured to support the rotationally coupled guide rail at two or more discrete rotational angles. The material sorter, where the guide rail includes first and second guide rails coupled together at respective first and second first ends to form an angled pair having an angle between the first and second guide rails and an apex pointing towards the top portion of the top surface of the rigid inclined panel. The material sorter, further including a second actuator able to rotate the first and second rotationally coupled guide rails to change the angle. The material sorter, where the guide rail includes third and fourth guide rails coupled near opposing sides of the rigid inclined panel and angled with first and second lower ends of such third and fourth guide rails, respectively, closer to the centerline than first and second upper ends of such third and forth guide rails, respectively. The material sorter, where the third and fourth guide rails comprise third and fourth guide rails rotationally coupled to the rigid inclined panel, able to rotate slidingly on the top surface of the rigid inclined panel. The material sorter, further including a third actuator able to rotate the third and fourth rotationally coupled guide rails. The material sorter, where the guide rail includes: a set of first and second guide rails coupled together at respective first and second first ends to form an angled pair having an angle between the first and second guide rails and an apex pointing towards the top portion of the rigid inclined panel, where the apex is near the centerline; a set of third and fourth guide rails coupled to the rigid inclined panel near opposing sides of the rigid inclined panel and angled with first and second lower ends of such third and fourth guide rails, respectively, closer to the centerline than first and second upper ends of such third and fourth guide rails, respectively. The material sorter, where the set of first and second guide rails coupled together includes a set of first and second guide rails rotationally coupled together. The material sorter, further including a third actuator able to rotate the first and second rotationally coupled guide rails to change the angle. The material sorter, where the set of third and fourth guide rails includes third and fourth rotationally coupled guide rails, able to rotate slidingly on the top surface of the rigid inclined panel. The material sorter, further including a first actuator able to rotate the third and fourth rotationally coupled guide rails. 
     A material sorter including: a rigid inclined panel having, a top surface, a top portion of the top surface, and an inclined centerline; one or more first guide rails abutting the top surface and coupled to the rigid inclined panel at a first angle to the center line that is not parallel to the center line; one or more second guide rails abutting the top surface and coupled to the rigid inclined panel at a second angle to the center line that is not parallel to the center line; and where a load of a mixed-density material dumped on the top portion of the inclined plane will move downward to at least partially impact the guide rail, thereby changing a first downward path of lower density material of such a mixed-density material differently than a second downward path of higher-density material of such a mixed-density material, to assist in sorting the load of mixed-density material. The material sorter, including a plurality of material sorters each having a corresponding plurality of different and distinct configurations of the first guide rail and the second guide rail, where each distinct configuration is adapted for assisting in sorting a correspondingly distinct mixed-density material. The material sorter, where the one or more first guide rails and/or the one or more second guide rails includes a rotational coupling to the rigid inclined plane; and further including an actuator for rotating each first guide rail and/or each second guide rail. The material sorter, where the first guide rail and/or the second guide rail includes a rotational coupling to the rigid inclined plane. The material sorter, further including one or more actuators for rotating one or more first guide rails and/or one or more second guide rails. 
     A material sorter including: a rigid inclined panel having, a top surface, a top portion of the top surface, and an inclined centerline; a first guide rail abutting the top surface and coupled to the rigid inclined panel at a first angle to the center line that is not parallel to the center line; a second guide rail abutting the top surface and coupled to the rigid inclined panel at a second angle to the center line that is not parallel to the center line; one or more actuators coupled to the rigid inclined panel and to one or more first guide rails and/or one or more second guide rail; and where a load of a mixed-density material dumped on the top portion of the inclined plane will move downward to at least partially impact the guide rail, thereby changing a first downward path of lower density material of such a mixed-density material differently than a second downward path of higher-density material of such a mixed-density material, to assist in sorting the load of the mixed-density material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
         FIG. 1  is a side view illustrating a prior art screening device; 
         FIG. 2  is a front view illustrating the prior art screening device of  FIG. 1 ; 
         FIG. 3  is a side view illustrating an exemplary material sorter mounted on a prior art screening device, according to a preferred embodiment of the present invention; 
         FIG. 4  is a view normal to an exemplary panel of the exemplary sorter of  FIG. 3 , according to a preferred embodiment of the present invention; 
         FIG. 5  is a view normal to an exemplary panel of an alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 6  is a view normal to an exemplary panel of another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 7  is a view normal to an exemplary panel of yet another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 8  is a view normal to an exemplary panel of still yet another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 9  is a view normal to an exemplary panel of still yet another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 10  is a view normal to an exemplary panel of still yet another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; 
         FIG. 11  is a view normal to an exemplary panel of still yet another alternate exemplary embodiment of a material sorter, according to a preferred embodiment of the present invention; and 
         FIG. 12  is a view normal to an exemplary panel of a plurality of alternate exemplary embodiments of a material sorter, according to a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
       FIG. 1  is a side view illustrating a prior art screening device  100 . Debris  114  is deposited and moved on perforated screen  102  and small material  116  accumulates below screen  102 . Screen  102  is supported horizontally by front wall  110  and side walls  110  (one visible in this view). Backstop  104  prevents material  114  from spilling over the back and sloped side walls  108  (one visible in this view) contain the material against lateral spillage. Access to the small material is though rear opening  106 . Prior art screening device  100  is shown as a support for the material sorter  300  (See  FIG. 3 ). Various businesses that would use material sorter  300  would already have prior art screening device  100 , making a material sorter  300  that is adapted to be mounted on such prior art screening device  100  particularly inexpensive. In various embodiments, various support structures  100  can be used. 
       FIG. 2  is a front view illustrating the prior art screening device  100  of  FIG. 1 . 
       FIG. 3  is a side view illustrating an exemplary material sorter  300  mounted on a prior art screening device  100 , according to a preferred embodiment of the present invention. Material sorter  300  includes rigid panel  302 , which is preferably a steel panel  302 , or steel plate  302 , but, in alternate embodiments may be made of other rigid materials. In operation, rigid panel  302  is inclined at an angle α. Rigid panel  302  is preferably ten to fourteen feet wide and sits, on its front edge, above a front wall  110  that is preferably three to six feet high. Inclined rigid panel  302  may have a lip  303  to assist in securing inclined rigid panel  302  to prior art screening device  100 . Lip  303  is an example of adaptations to inclined rigid panel  302  that assist in mounting the material sorter  300  to the prior art screening device  100 . Prior art screening device  100  is merely an example of a means for supporting material sorter  300 . Those of skill in the art, enlightened by the present disclosure, will be aware of various structures that can support the material sorter  300 , and of various adaptations to the rigid panel  302  that can be made to help install the material sorter  300  on such structures. In a preferred embodiment, the inclination angle α may be varied mechanically, hydraulically, manually, or by similarly affective means. 
     Converging guide rail  304  is attached, or coupled, to rigid panel  302 . Diverging guide rail  306  is also attached, or coupled, to rigid panel  302 . Guide rails  304  and  306  are preferably one to three feet high, and should be shorter than the height dimension of the higher density material in the mixed-density material to be sorted. In a particular embodiment, guide rails  304  and  306  may be outside the preferred range. Material sorter  300  is shown at an incline angle α of forty-five degrees, but angles α between thirty and seventy five degrees are in the preferred range, depending on the materials to be sorted. For sorting cardboard from construction debris, for example, an incline angle α of thirty-two degrees has produced the best results in testing. In a particular embodiment, the incline angle α may be variable and actuated by manual, mechanical, motorized, or hydraulic means. Preferably, the entire apparatus is less than twelve feet high. 
       FIG. 4  is a view normal (perpendicular) to an exemplary panel  302  of the exemplary sorter  300  of  FIG. 3 , according to a preferred embodiment of the present invention. Inclined rigid panel  302  has a top surface  412  and a top portion  414  of that top surface, which is the area where the multi-density material to be sorted is deposited during operation. Inclined rigid panel  302  has a centerline  408 , which shares the same inclination α as the inclined rigid panel  302 . While inclined rigid panel  302  is illustrated as being generally rectangular, the invention is not so limited. The shape may be adapted to facility requirements. 
     Diverging guide rails  306  and  406  are covered by rigid panel  402  and form an apex  410  which points toward the top portion  414  and is on or near the inclined centerline  408 . In a particular embodiment, rigid panel  402  may be omitted. Converging guide rails  304  and  404  direct the mixed-density material to be sorted in its gravity-powered travel down the inclined rigid panel  302  into diverging guide rails  306  and  406 , slowing low density materials more than high density ones, and causing the light weight (low density) materials to move along a more outward path while the heavy (high density) materials hill more directly, thereby separating the materials on the floor in front of the material sorter  300 . Guide rails  304 ,  306 ,  404 , and  406  are shown as straight, but may, in various embodiments, be curved or angular. The height of guide rails  304 ,  306 ,  404 , and  406  is not limited to constant heights. Converging guide rails  404  and  304  are positioned at a first angle to centerline  408 . (See  FIG. 9 ). Diverging guide rails  306  and  406  make a second angle to centerline  408 , and form an angled pair of guide rails  306  and  406 . 
       FIG. 5  is a view normal (perpendicular) to an exemplary panel  302  of an alternate exemplary embodiment of a material sorter  500 , according to a preferred embodiment of the present invention. Diverging guide rails  506  and  508  are smaller in this embodiment, as is covering panel  502 . Apex  510  of angled pair  306  and  406  is lower than apex  410 . Material sorter  500  is preferred for dryer materials than that used with material sorter  300 . While diverging rails  506  and  508  are shown with the apex  510  centered, the apex  510  for  410 ) may be off center in some embodiments. 
       FIG. 6  is a view normal to an exemplary panel  302  of another alternate exemplary embodiment of a material sorter  600 , according to a preferred embodiment of the present invention. Guide rails  604 ,  606 , and  608 , decelerate the downwardly flowing debris but retard the lightweight materials more than the denser materials, thereby achieving separation. In various embodiments, the angles at which guiderails  604 ,  606 , and  608  hae to centerline  408  may vary from that shown, or may be variable (in unison or individually) by mechanical, including hydraulic, or manual means. Different types of mixed-density material are best sorted by correspondingly different angles, which may be determined by simple experimentation. 
       FIG. 7  is a view normal to an exemplary panel  302  of yet another alternate exemplary embodiment of a material sorter  700 , according to a preferred embodiment of the present invention. Guide rail  702  separates the flow of debris into two streams and guides both into converging guide rails  704  and  706 , which direct the flow into diverging guide rail  708 . Adaptive to various mixed-density materials, the sizes and positions of diverging guide rails  702  and  708 , and the angles and lengths of converging guide rails  704  and  708 , may vary. 
       FIG. 8  is a view normal (perpendicular) to an exemplary panel  302  of still yet another alternate exemplary embodiment of a material sorter  800 , according to a preferred embodiment of the present invention. The converging guide rails  804  and  808  have pivots  812  and  814 , respectively, and actuators (not shown) to adjust the angle at which converging guide rails  804  and  808  operate. Converging guide rails  804  and  808  rotate slidingly on the top surface  412  of inclined rigid panel  302 . Actuator  802  moves diverging guide rails  806  and  807  about pivot  810 . Guide rails  804  and  808  may be releasably fixed at two or more discrete rotational angles by releasable mechanical connection to the inclined rigid panel  302 . For example, captive pins (not shown) on the guiderails  804  and  808  may be received in aligned holes (not shown) in the inclined rigid panel  302 . 
     Diverging guide rails  806  and  807  rotate slidingly on the top surface  412  of inclined rigid panel  302 . Diverging guide rails  806  and  807  are coupled together by pivot  810  to form an angled pair having angle β. Diverging guide rails  806  and  807  may be covered with a two-piece cover, where one piece slides over another (not shown). In a particular embodiment, diverging guide rails  806  and  807  can be rotated separately by individual actuators. Guide rails  806  and  807  may be releasably fixed at two or more discrete rotational angles by releasable mechanical connection to the inclined rigid panel  302 . For example, captive pins (not shown) on the guiderails  806  and  807  may be received in aligned holes (not shown) in the inclined rigid panel  302 . 
       FIG. 9  is a view normal (perpendicular) to an exemplary panel  302  of still yet another alternate exemplary embodiment of a material sorter  900 , according to a preferred embodiment of the present invention. Rotatable guide rail  902  can be rotated about pivot  914  by an actuator (not shown) to move slidingly over the top surface  414  of inclined rigid panel  302 . Rotatable guiderail  902  makes an angle γ with inclined centerline  408 . Guide rail  902  may be releasably fixed at two or more discrete rotational angles by releasable mechanical connection to the inclined rigid panel  302 . For example, captive pins (not shown) on the guiderail  902  may be received in aligned holes (not shown) in the inclined rigid panel  302 . In a mechanically actuated embodiment, guiderail  902  may also be used to sweep debris off panel  302 . 
       FIG. 10  is a view normal (perpendicular) to an exemplary panel  302  of still yet another alternate exemplary embodiment of a material sorter  1000 , according to a preferred embodiment of the present invention. Diverging guiderail  1002 , which may be regarded as an angled pair, deflects low-density material to the outside while the high-density material falls over the diverging guide rail  1002 . Various diverging guiderails  1002  may be used in various embodiments. 
       FIG. 11  is a view normal (perpendicular) to an exemplary panel  302  of still yet another alternate exemplary embodiment of a material sorter  1100 , according to a preferred embodiment of the present invention. Converging guide rails  1004  and  1006  may be, in a particular embodiment, pivoted and/or mechanically actuated. 
       FIG. 12  is a view normal (perpendicular) to an exemplary panel  302  of a plurality  1200  of alternate exemplary embodiments of a material sorter  900 ,  1000 , and  1100 , according to a preferred embodiment of the present invention. Any number of embodiments may be used together in an arrangement, such as the linear array shown, wherein each material sorter is configured for sorting a particular mixed-density material, and the loader may select the configuration appropriate to the load that has arrived for sorting. In combination with the embodiments shown, any or all other embodiments may be used in an arrangement. While a linear array is illustrated, any arrangement that is convenient in the sorting facility is within the scope of the present invention. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention.