Abstract:
A motorized paddle assembly for a material sorter is presented. The motorized paddle assembly comprises a paddle, internal mechanisms, and a housing that encloses the internal mechanisms. The paddle is attached to a circular hinge to enable the circular hinge and the paddle to rotate about an axis. The motorized paddle assembly includes an upper plate for the circular hinge. The upper plate allows the free rotation of the circular hinge while substantially preventing unwanted material from falling behind the circular hinge. In a series of adjacent motorized paddle assemblies, a gasket is mounted between adjacent motorized paddle assemblies to substantially prevent unwanted material from falling between the adjacent motorized paddle assemblies.

Description:
[0001]    This application takes priority from U.S. provisional application 60/912,566 filed Apr. 18, 2007, which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The recycling industry sorts and separates reusable materials out of collected materials. The sorted and separated reusable materials are reprocessed into raw materials in other applications while the unusable material is typically sent to a landfill. Machines, called sorters, are often used to mechanically sort and separate a variety of types of materials from a material stream. The material stream is passed through the detection range of any of a variety of sensors that detect metals, plastics, glass, or other parameters like size and color that can be sorted and separated from the material stream. 
       SUMMARY 
       [0003]    A motorized paddle assembly for a material sorter is presented. The motorized paddle assembly comprises a paddle, internal mechanisms, and a housing that encloses the internal mechanisms. The paddle is attached to a circular hinge to enable the circular hinge and the paddle to rotate about an axis. The motorized paddle assembly includes an upper plate for the circular hinge. The upper plate allows the free rotation of the circular hinge while substantially preventing unwanted material from falling behind the circular hinge. 
         [0004]    Some embodiments of motorized paddle assemblies have two hinges for each paddle. In these embodiments, the upper plate has openings for each hinge. 
         [0005]    In a series of adjacent motorized paddle assemblies, a gasket is mounted between adjacent motorized paddle assemblies to substantially prevent unwanted material from falling between the adjacent motorized paddle assemblies. 
         [0006]    Some embodiments can have a seal between the circular hinge and the internal mechanisms of the motorized paddle assembly. This seal can be made of felt or any other appropriate material and can be oil impregnated. 
         [0007]    Those skilled in the art will realize that this invention is capable of embodiments that are different from those shown and that details of the devices and methods can be changed in various manners without departing from the scope of this invention. Accordingly, the drawings and descriptions are to be regarded as including such equivalent embodiments as do not depart from the spirit and scope of this invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]    For a more complete understanding and appreciation of this invention, and its many advantages, reference will be made to the following detailed description taken in conjunction with the accompanying drawings. 
           [0009]      FIG. 1  is an embodiment of a sorter that can incorporate an array of control modules as described herein; 
           [0010]      FIG. 2  is a schematic showing a prior art control system of a sorter; 
           [0011]      FIG. 3A  is a perspective view of one embodiment of a motorized paddle that could be used in a control module; 
           [0012]      FIG. 3B  is a perspective rear view of the motorized paddle of  FIG. 3A ; 
           [0013]      FIG. 3C  is a cross-sectional view of the motorized paddle of  FIG. 3B  along the Section line  3 C- 3 C; 
           [0014]      FIG. 4  is a perspective view of an upper plate that is inserted between a paddle and motorized paddle assembly housing; 
           [0015]      FIG. 5  is a perspective view of two adjacent motorized paddle assemblies that incorporate an embodiment of the sealing features; 
           [0016]      FIG. 6  is a perspective view of the front of four adjacent motorized paddle assemblies that incorporate an embodiment of the sealing features; and 
           [0017]      FIG. 7  is a perspective view of the rear of five adjacent motorized paddle assemblies that incorporate an embodiment of the sealing features. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to the drawings, some of the reference numerals are used to designate the same or corresponding parts through several of the embodiments and figures shown and described. Corresponding parts are denoted in different embodiments with the addition of lowercase letters. Variations of corresponding parts in form or function that are depicted in the figures are described. It will be understood that variations in the embodiments can generally be interchanged without deviating from the invention. 
         [0019]    Sorters in the recycling industry use a variety of methods to detect and sort different types of material from a material stream.  FIG. 1  shows an example of such a sorter  10 . The sorter  10  is a ProSort manufactured by Eriez Magnetics located in Erie, Pa. The sorter  10  accepts material from upstream sources  12  and has a material introduction system  14  that is a vibrating chute angled to deposit a material stream onto the width of a material handling system  16 . The material handling system  16  comprises a conveyor belt that transports the material stream from about a first end  18  where the material stream is deposited to about a second end  20 . 
         [0020]    This sorter  10  has a material detection system that comprises at least one sensor that is positioned to detect materials in the material stream. The sensor or sensors are able to detect at least one type of material in the material stream within their range of effectiveness and are arranged to be effective substantially across the width of the material handling system  16 . The sensor or sensors are controlled by a control system located in the control system housing  24 . The sorter  10  is able to sort the material in the material stream based on the readings of the sensor or sensors. This sorting is conducted by a sorting system that comprises a series of motorized paddles assemblies  26 . 
         [0021]    The material stream passes through the detection range of the material detection system as it is conveyed from the first end  18  to the second end  20 . When a sensor of the material detector detects a target type of material in the material stream, the control system in the control system housing  24  either sends a timed signal to the corresponding motorized paddle assembly  26  to deflect the material or does nothing and lets the material drop past the motorized paddle assemblies  26  as required by the current configuration of the sorter  10 . 
         [0022]      FIG. 2  shows a prior art motorized paddle assembly  26   a,  which comprises a housing  28   a  that encloses the internal mechanism (not shown) that operates the motorized paddle assembly  26   a,  a paddle  30   a  mounted to a hinge  32   a,  and a cable connector  34   a  that connects the motorized paddle assembly  26   a  to the sorter control system. The cable connector  34   a  sends and receives signals between the sorter control system and the motorized paddle assembly  26   a.  These motorized paddle assemblies  26   a  operate in high dust and grit environments. The housing  28   a  has a shoulder in which the hinge  32   a  sits that defines the range of motion of the hinge  32   a.  An opening (not shown) in the housing  28   a  connects the hinge  32   a  to the internal mechanism of the motorized paddle assembly  26   a.  The prior art embodiment shown in  FIG. 2  is subject to frequent breakdowns and high maintenance costs. The prior art hinge  32   a  is prone to debris falling behind the hinge  32   a.  Debris, dust, and grit builds up over time and physically impedes the range of motion of the hinge  32   a.  There is a chance that some of the accumulating debris may work its way into the motorized paddle assembly  26   a  housing  28   a.  If this happens, the debris could interfere with the operation of the internal mechanisms and control circuitry (not shown) of the motorized paddle assembly  26   a.  When multiple prior art motorized paddles  26   a  are installed in series on sorters as shown, for example in  FIG. 1 , gaps between each motorized paddle assembly  26   a  allow debris to build up between each motorized paddle assembly  26   a.  Over time the debris builds up to the level of the cable connector  34   a.  The debris can impinge and damage the cable connector  34   a.    
         [0023]    Some prior art embodiments incorporate magnets as part of the internal mechanism within the housing  28   a.  These magnets operate within the motorized paddle assembly  26   a  with narrow clearances. As many of these devices are installed in environments in which they are exposed to ferrous material in the form of rust, dust, or other matter, the lack of a good seal means that these prior art devices constantly attract ferrous debris that causes the internal mechanisms to fail with debris fouling the internal mechanisms or interfering with the narrow clearances. 
         [0024]    All of these limitations cause damage that would require maintenance or replacement of the motorized paddle assemblies  26   a  and could put the sorter out of commission while the problem is addressed. This wasted downtime represents a significant bottleneck in a facility&#39;s productivity. 
         [0025]    Various embodiments of the invention have been developed to address these limitations. One embodiment is shown depicted in  FIG. 3A . As can be best understood by comparing FIGS.  3 A- 3 C, the motorized paddle assembly  26   b  comprises a paddle  30   b,  internal mechanisms (described below), and a housing  28   b  to cover and protect the internal mechanism. The paddle  30   b  is attached to hinge  32   b.  The housing  28   b  has a shoulder in which the hinge  32   b  is seated. An opening (not shown) in the housing  28   b  allows the hinge  32   b  to be attached to bearings (not shown) that are connected a shaft  38   b.  An electromagnetic coil  36   b  is suspended from the shaft  39   b.  The bearings (not shown) allow the shaft  38   b  and the electromagnetic coil  36   b  to swing freely. The electromagnetic coil  36   b  is sandwiched between two sets of fixed permanent magnets  40   b  (only one set is shown in the figures). The electromagnetic coil  36   b  is close to the magnets  40   b  but does not touch them. There is a clearance of about 0.030 inches on either side of the electromagnetic coil  36   b  between the magnets  40   b  and the electromagnetic coil  36   b.    
         [0026]    The motorized paddle assembly  26   b  is connected to the module&#39;s control circuitry (not shown) through the motorized paddle assembly cable connector  34   b.  When the motorized paddle assembly  26   b  is at rest, a −5 VDC (Voltage, Direct Current) is applied to the leads (not shown) of the electromagnetic coil  36   b.  This creates a magnetic field in the electromagnetic coil  36   b  that causes the electromagnetic coil  36   b  to swing on the shaft  38   b  and align itself to the appropriate opposite polarity of the magnets  40   b  and causes the paddle  30   b  to remain in the rest position. When the motorized paddle assembly  26   b  is actuated, a +16.5 VDC voltage is sent to the leads (not shown) of the electromagnetic coil  36   b  that causes the electromagnetic coil  36   b  to align itself with the magnets  40   b  towards the front of the housing  38   b.  This correspondingly causes the paddle  30   b  to swing outwards. A −5 VDC current is applied to return the paddle  30   b  to the retracted position. Shock absorbers  42   b  absorb some of the vibration experienced by the paddle  30   b  during actuation and return. As mentioned above, the small clearances between the magnets  40   b  and the electromagnetic coil  36   b  are susceptible to fouling if the motorized paddle assembly  26   b  is not properly sealed. The motorized paddle assembly cable connector  34   b  allows the control circuitry to monitor signals received from the motorized paddle assembly  26   b  and to provide signals to the motorized paddle assembly  26   b  as needed. 
         [0027]    In order to reduce the chances of the paddle  30   b  of the motorized paddle assemblies  26   b  getting stuck, the hinges  32   b  on which the paddle  30   b  rotates are circular. Any debris that falls behind the hinge is unlikely to impinge the range of motion of the hinge  32   b.  An upper plate  44   b  is mounted on the motorized paddle assembly  26   b  to further reduce the amount and size of debris that can fall behind the hinge  32   b.  As can be understood by comparing  FIGS. 3A and 4 , the upper plate  44   b  has openings  46   b  sized to fit the hinges  32   b  that allows the hinges  32   b  to move their full range of motion while substantially blocking dust and debris from falling behind the hinges  32   b.    
         [0028]    A seal  47   b  can be included between the hinge  32   b  and the housing  28   b  to keep dirt and moisture away from the bearings and to also act as a wiper for the circular hinge  32   b.  The seal  47   b  surrounds the opening in the housing  28   b  and is sufficiently large to cover the back of the hinge so that dirt cannot get between the hinge  32   b  and the housing  28   b.  The seal  47   b  can be made of felt or any other appropriate material and can be oil impregnated if appropriate. The seal provides an additional level of protection from dust and debris entering the housing  26   b  and damaging the inner mechanisms of the motorized paddle assembly  26   b.    
         [0029]    Multiple motorized paddle assemblies  26   b  are arranged side by side on sorters as shown in  FIGS. 5 ,  6  and  7 . To further seal the array of motorized paddle assemblies  26   b  against dust and grit collecting between individual motorized paddle assemblies  26   b,  gaskets  48   b  are installed between adjacent motorized paddle assemblies  26   b.  This reduces the build up of grit between the motorized paddle assemblies  26   b  that could eventually pinch or sever any cable connections to/from the motorized paddle assemblies  26   b  or impede the range of motion of the hinges  32   b.    FIGS. 5   6 , and  7  show the gaskets  48   b  mounted to the upper plates  44   b  of adjacent motorized paddle assemblies  26   b,  but other configurations of gaskets  48   b  are possible so long as dust and debris are substantially blocked from falling between the motorized paddle assemblies  26   b.    
         [0030]    This invention has been described with reference to several preferred embodiments. Many modifications and alterations will occur to others upon reading and understanding the preceding specification. It is intended that the invention be construed as including all such alterations and modifications in so far as they come within the scope of the appended claims or the equivalents of these claims.