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This application is a continuation of Ser. No. 10/382,958, filed Mar. 6, 2003 now abandoned. 

   BACKGROUND OF THE INVENTION 
   The invention relates to improvements in compactor cleats, particularly suited for landfill operations. 
   PRIOR ART 
   Landfill space is most valuable where it is most needed, e.g. where an area is densely populated. As a population center grows, the land area it needs for residential, commercial, industrial and recreational space increases. Simultaneously, the increase in population produces a proportionate increase in waste. With less land available and more waste being generated, the need to use landfill space efficiently becomes greater if not urgent. To improve the volumetric efficiency of a landfill, it has become the practice to compress the waste dumped there by repeatedly running over it with large wheeled tractors or “compactors” or with track mounted tractors or crawlers. These tractors have features designed particularly for this purpose. The wheeled tractors are fitted with heavy all-steel wheels that include cleats intended to compress the waste by concentrating the weight of the tractor on the relatively small area of the cleats. Various types and geometries of cleats have been proposed for this service but there has remained a need for increasingly more efficient compactor cleats. 
   SUMMARY OF THE INVENTION 
   The invention provides a compactor cleat for a wheel or a track pad that has improved compaction performance compared to other known cleats. On a wheel, the cleat increases the rate and degree of compaction by reducing wheel spinning that otherwise results from loss of traction. By maintaining traction, the cleat of the present invention avoids churning up and in effect decompacting waste material that has already been compacted by the current and any previous passes of the wheels on the landfill area being treated. 
   The cleat of the invention is characterized by a bi-directional pocket geometry enabling a compactor to work well in both forward and reverse directions. As disclosed, the cleat is symmetrically arranged with gripping pockets on its forward and rearward faces. The pockets have a width in the axial direction of a wheel to which it is attached that is at least ½ of the width of the cleat and, preferably, is even greater. Further, this width is preferably about the same as the height of the cleat measured in the radial direction. In either direction, the cleats have broad leading faces that avoid leading edges which can cut into the waste material being compacted and thereby diminish traction. Ideally, for at least half of the height of the cleat, its pocket faces are generally radially oriented. The cleats are spaced on a wheel on centers along circumferential lines with the cleat centers of adjacent lines being staggered or out of phase. Preferably, the collective width of the cleats in the axial direction on a wheel is about equal to the width of a wheel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first embodiment of a clear constructed in accordance with the invention; 
       FIG. 2  is a front elevational view of the cleat of  FIG. 1 ; 
       FIG. 3  is a side elevational view of the cleat of  FIG. 1 ; 
       FIG. 4  is a plan view of the cleat of  FIG. 1 ; 
       FIG. 5  is a bottom view of the cleat of  FIG. 1 ; 
       FIG. 6  is a cross-sectional view of the cleat taken in the plane indicated by the lines  6 — 6  in  FIG. 4 ; 
       FIG. 7  is a perspective view of a typical compactor wheel on which is mounted a plurality of cleats of the type illustrated in  FIG. 1 ; 
       FIG. 8  is a front perspective view of the wheel and cleats of  FIG. 7 ; 
       FIG. 9  is a perspective view of a modified form of the cleat, being a mirror image of the cleat of  FIG. 1 ; 
       FIG. 10  is a perspective view of a second embodiment of a cleat constructed in accordance with the invention; 
       FIG. 11  is a plan view of the cleat of  FIG. 10 ; 
       FIG. 12  is a side elevational view of the cleat of  FIG. 10  taken from the left; 
       FIG. 13  is a side elevational view of the cleat of  FIG. 10  taken from the right; 
       FIG. 14  is a fragmentary perspective view of a succession of three cleats bolted to an endless track; and 
       FIG. 15  is a side view of a crawler type tractor on which the cleats of  FIG. 10  are employed. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings and, in particular, to  FIGS. 1–6  there is illustrated an example of a cleat  10  constructed in accordance with the invention. The illustrated cleat  10  which can be made in one piece of steel and cast to shape has a main body  11  and a mounting base  12 . The main body  11  includes a generally prismatic Z-shaped formation  13 . The Z-shape is somewhat unfolded from a traditional shape in that opposed flanges  14  are displaced from one another along their planes so that a web  15  forms an obtuse angle with each of the flanges  14 . As illustrated, the flanges  14  are preferably planar and parallel to one another. A study of  FIG. 4  reveals that the prismatic portion  13  of the body  11  is symmetrical about two perpendicular planes that are each perpendicular to the plane of the figure and are indicated by the lines  17 ,  18 . The base  12  as viewed in  FIGS. 4 and 5  is generally rectangular having a perimeter  19  with opposed long sections  20  and opposed short sections  21 . The flanges  14  are each adjacent one of the long sections  20  of the base perimeter  19  and are distal from the perimeter section to which the opposed flange is adjacent. The thickness of the flanges  14  and web  15 , as shown, can be uniform. These flange and web elements  14 ,  15  can be, as mentioned, generally prismatic except for a nominal draft angle to facilitate casting of the cleat  10 . 
   As shown in  FIG. 3 , for example, a large fillet  22  is provided between each flange  14  and the distal base perimeter section  21 . The fillet serves to avoid a “tight” corner between the flange  14 , and portions of the web  15 , and the base  12  which could otherwise accumulate waste material and reduce the pressure that the cleat  10  can produce on the waste at its outer face  23 . The outer face  23  is common to the flanges  14  and web  15  of the prismatic Z-shaped portion  13  and can be generally planar and perpendicular to the imaginary planes that are perpendicular to the plane of  FIG. 4  through the lines  17 ,  18 . A bottom or inner face  26  of the base  12  is concave so as to provide surface areas that work in the manner of a saddle to enable the cleat  10  to set on and align with the outer surface of a cylindrical wheel as described hereinbelow. This alignment afforded by the surface areas of the inner face  26  of the base  12  puts the mid-plane, represented by the line  18  in  FIG. 4  of the prismatic body portion  13  in alignment with an imaginary radial plane parallel to and passing through the axis of a cylindrical wheel on which the cleat is mounted. The alignment surface areas can include, as shown, a cylindrical area  27  at opposed perimeter sides  21  of the base  12 . The radius of the cylindrical surface areas  27  is preferably equal to or slightly less than the radius of the outside diameter of a wheel on which the cleat is to be attached. A typical outside diameter of a wheel is between about 40″ to 60″. It will be understood by those skilled in the art that the base can provide contact areas for saddling and aligning onto the outside diameter of a wheel that are not cylindrical and that at a minimum provide three points of contact, one adjacent one of the long perimeter sides  20 , and two adjacent the opposite long perimeter sides  20 . It is desirable that the contact areas and other parts of the base are configured so that a major portion, if not all, of the perimeter  19  lies close to the cylindrical surface of the wheel, e.g. within ⅜ inch so that one or two passes of a welding rod or wire is adequate to completely form an adequate weld fillet along the perimeter  19  of the base  12 . 
     FIGS. 7 and 8  illustrate application of the inventive cleat on a compactor wheel  31 . The wheel  31  along with three similar units are assembled on a tractor or compactor that operates back and forth along a landfill to crush, compact and otherwise densify debris or waste to conserve the landfill volume. A plurality of cleats  10  are welded on the outer cylindrical ground engaging surface port of the wheel  31  in a generally known manner. Preferably, the cleats  10  are arranged with a uniform arcuate or circumferential spacing in circumferential rows. Preferably, the cleats  10  of adjacent rows are out of angular alignment or phase with one another. 
   From the foregoing it will be understood that the cleats  10  when properly located on the cylindrical wheel surface by the saddle or locating surfaces represented by the cylindrical surface areas  27  and welded in place are each generally aligned both radially and axially with respect to an axis  33  of the wheel. 
   It will be seen that the cleat  10 , once welded to the wheel  31  is very stable and rugged, owing to its disclosed geometry. The width of the illustrated cleat  10  measured in a direction parallel to the planes of the flanges  14  is greater than the height of the cleat while the length measured in the direction perpendicular to the planes of the flanges is about the same as the height. The illustrated cleat  10 , by way of example, has nominal dimensions of 7″ height, 10″ width, and 7″ length. The flanges  14  interconnected by the web  15  create a very stiff, robust structure not readily damaged or knocked off a wheel. 
   The cleat  10  creates a pocket  36  in the convex space between the trailing flange  14  with reference to the direction of rotation of the wheel  31 , the web  15  and the fillet  22 . This pocket  36  has demonstrated improved traction capability, operating in concert with the identical cleats on the associated wheel and the other wheels of a compactor. While no complete explanation is presently known for the improved traction performance of the disclosed cleat  10 , it has been theorized that the pocket  36  works something like a cupped hand used by a swimmer to increase coupling with the water. That is to say, it is believed that the pocket  36  increases traction over what would be available from a simple flat or plate-like cleat. Additionally, the blunt faces of the flanges  14  and web  15 , unlike other prior art cleat designs, avoid shearing the material being compacted to thereby afford a better, more stabilized grip in the material being compacted. Because the cleat  10  is symmetrical about the radial plane associated with the line  18 , it has the same characteristics with a pocket and blunt flange and web faces on both of its faces. Consequently, the cleat is bi-directional in its effectiveness when the compactor is going forward or rearward. 
   It has been found that the same style cleat  10  can be used on wheels mounted on both the right and left side of a machine or tractor without experiencing any significant side thrust. It is contemplated that the cleat of the invention can be modified by making it as an S-version or, more properly, an unfolded S-version where the flanges are offset from one another in their planes. This version of a cleat  110  is shown in  FIG. 9 . If desired, a compactor can be arranged with all Z-cleats on the wheels on one side and all S-cleats on the wheels of the opposite side. Alternatively, each wheel can have a mixed arrangement of Z and S cleats. While the flanges  14  and web  15  have been shown with flat and angular features, it is contemplated that certain of these features can be modified while the traction pocket  36  is retained. Such modification can include the use of moderately curvilinear surfaces or profiles. 
     FIGS. 10–15  illustrate another embodiment of the invention as it is applied to a track or crawler-type vehicle  40 . The illustrated vehicle  40  is fitted with a pair of endless track chains  41 , one on each side of the machine as is conventional. Bolted to the track chain are shoes or pads  42  constructed in accordance with the invention. The shoes or ground engaging parts  42  on each track chain  41  can be identical. A shoe, which can be constructed of cast steel, has a base  43  which is generally rectangular in plan view as shown in  FIG. 11 . The shoes  42  include a cleat  44  integral with a base  43  which in the illustrated example, has a stretched Z-shape. A study of  FIGS. 12 and 13  show that the cleat  44  has an upper face  46  that, preferably, lies in a plane parallel to the base  43 . 
   For reference purposes, the length of the shoe base  43 , measured in the direction of travel, can range between about 6½″ to about 10¼″ and the width of the shoe base can range between about 14″ and about 36″. The cleat  44  has a height above the base  43  of about 3″, for example. The cleat  44  has self-cleaning traction pockets  47 ,  48  for forward and rearward operation of the crawler or tractor  40 . Each pocket  47 ,  48  exists in a zone bound by a flange  51  or  52  and a web  53 , forming an obtuse angle therebetween and a concave fillet surface  54  or  55 . The fillet surface  54 ,  55 , making a smooth transition between the base  43  and flange  51 ,  52  reduces the risk that refuse will become severely lodged in the respective pocket  47 ,  48 . 
   As with the cleat  10  described in connection with  FIGS. 1–9 , the cleat  44  is bi-directional with the pocket  47  operating to improve traction in the forward direction of the crawler or machine  40  and the pocket  48  operating to improve traction in the rearward direction. At the same time, the shoes  42  increase the compaction of waste or other material by increasing the pressure that the shoes develop at the relatively small area of the cleat face  46 , as compared to the plan area of the shoe. 
   As discussed previously in connection with the cleat  10 , the cleat  44  can have its flanges  51 ,  52  and web  53  modified into curvilinear shapes, as desired. Additionally, the cleat  44  can be made in a configuration that is a mirror image so that it has the shape of a stretched S. Z and S cleats can be used on opposite sides of the crawler  40  and/or can be used alternately on the same side of the machine. 
   While the invention has been shown and described with respect to particular embodiments thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiments herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly, the patent is not to be limited in scope and effect to the specific embodiments herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.

Summary:
A cleat for compacting refuse at a landfill by use on the wheels of a compactor or on the shoes of a crawler-type tractor. The cleat has a prismatic modified Z or S configuration that affords superior compaction performance by increasing traction and thereby reducing churning of already compacted material. The flanges of the cleat create traction pockets on opposite sides so that the cleat is effective in either direction of the compactor or tractor.