Abstract:
A comminuting mechanism is disclosed that includes a rotatable drive shaft which supports a plurality of blades, each blade having both straight arms and arms having angled tip portions. The shaft and blades are supported on a frame within a hood, and the frame is pulled along a ground surface by a tractor or other vehicle. Debris is pulled into the housing by the combined action of the forward motion of the vehicle and an inward airflow generated by fan members on the rotating blades, pulverized by the action of the blades, and discharged through an outlet.

Description:
TECHNICAL FIELD 
     The present invention relates generally to a comminuting apparatus, and more particularly, to a movable apparatus for comminuting debris on a golf course or other ground surface. 
     BACKGROUND OF THE INVENTION 
     Golf courses, playing fields, and other turf surfaces are frequently subjected to heavy traffic and thus require frequent maintenance and care to keep them in good condition. One tool useful for keeping a turf surface healthy is an aerator, a device that punches holes in the turf surface and pulls out plugs of grass and soil. Plugging a turf surface in this manner allows air and moisture to penetrate the ground more quickly than an unaerated surface and also allows fertilizer to get down to the roots of the grass. 
     The plugs removed by an aerator are typically about five-eighths inch in diameter and one to four inches long, and these plugs are formed about four inches apart on a ground surface. Picking up and disposing of the plugs is expensive and removes and wastes valuable nutrients. However, until the plugs break down under the influence of sun, rain, and wind, they can interfere with the use of the turf. This problem is particularly pronounced when a golf course green is aerated, since plugs lying on the green would make putting nearly impossible. Attempts have therefore been made, with mixed success, to chop up the plugs and return the materials to the turf surface. 
     While flail type machines have been used for this purpose, they have not been very effective for a breaking up and redistributing of the plugs and thatch, particularly under wet or damp conditions. It is also has been proposed to use drag mats or blowers, both of which have also proved to be generally ineffective in properly removing the debris. Further, such procedures, at best, merely accumulate the debris to the side of the green or in the rough where the material is frequently left to slowly decompose, or must be manually removed. It would therefore be desirable to provide a apparatus for effectively comminuting plugs and grass and returning the comminuted material to a turf surface in a manner that does not interfere with the use of the turf surface. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a comminuting mechanism having a mobile support structure movable along a path of travel on a ground surface. A rotatable drive shaft is mounted within a housing and extends transversely of the path of travel and is supported by the mobile support structure. The comminuting mechanism further includes a mechanism such as a gasoline engine for rotating the rotatable shaft. The comminuting mechanism also includes a plurality of pulverizing blades, each having a hub with a central opening for mounting on the rotatable shaft within the housing. Each pulverizing blade includes a plurality of arms extending radially from the hub. A first set of straight arms radiates in the plane of the hub. Between each pair of straight arms lays a blade with an end or tip portion angled toward a first side or a second side of the plane of the hub. The direction of the angled arms alternates around the blade. The pulverizing blades are preferably mounted on the shaft so that the arms of adjacent blades are slightly offset rotationally from one another. Most if not all the straight arms include planar fan members mounted perpendicularly to the plane of the blade for creating an airflow into the housing when the shaft rotates. 
     The mechanism further includes a debris receiving opening in the bottom of the housing extending in the direction of the rotatable shaft for receiving ground debris along the path of travel substantially at ground level. The rotation of the blades and their fan members creates an airflow into the housing and helps draw grass plugs and other debris into the housing where they are pulverized by the action of the rotating blades and/or by collisions with the housing. After a partial circuit or one or more circuits around the rotating shaft, the pulverized debris is discharged through an outlet opening in the direction opposite to the direction of travel of the vehicle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the detailed description of the invention that follows and the following drawings wherein: 
     FIG. 1 is a perspective view of a mobile comminuting mechanism according to the present invention; 
     FIG. 2 is a side elevational view of the mobile comminuting mechanism illustrated in FIG. 1; 
     FIG. 3 is a perspective view of a pulverizing apparatus of the mobile comminuting mechanism shown in FIG. 1; 
     FIG. 4 is a perspective view of the pulverizing blades mounted on a central drive shaft; 
     FIG. 5 is an elevation view, partly in section, taken in the direction of line  5 — 5  in FIG. 3; 
     FIG. 6 in a sectional side elevation view taken in the direction of line  6 — 6  in FIG. 3; and, 
     FIG. 7 is a perspective view of a second embodiment of pulverizing blade for use with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for purpose of limiting the same, FIG. 1 shows the comminuting mechanism  10  of the present invention. Comminuting mechanism  10  includes a mobile frame  11  formed of welded bars  12 , preferably hollow so as to minimize the weight of comminuting mechanism  10 . Mobile frame  11  includes a pair of support wheels  14  mounted on a transverse axle  16  which support the rear of mobile frame  11 . While similar wheels may also be provided for the forward end of mobile frame  11 , in this embodiment a tractor hitch  18  is utilized both for engaging a towing vehicle and for supporting the forward end of mobile frame  11 . 
     The forward or front end of mobile frame  11 , from a lower cross rail  20  thereof, mounts a pair of laterally spaced and forwardly diverging gathering arms  22 , each with an outer ground engaging support roller  24 . Arms  22  may be transversely arced to provide a concave inner face to inwardly gather the encountered debris with a central directing thereof toward the advancing mobile frame  11 . Support rollers  24  preferably project only slightly below the forward ends of arms  22  providing for a proper gathering of the materials without an actual scrapping engagement with the ground surface. Appropriate vertical and rotational supports  26  may be provided on the inner ends of arms  22  for adjustment both with regard to the height thereof and the lateral spread. Arms  22  are pivotally mounted to supports  26 , as indicated at reference numeral  28 , for vertical pivotal movement thereof to provide a floating action and to accommodate ground surface irregularities. 
     Mobile frame  11  further comprises an inner floating frame  30  positioned transversely across mobile frame  11  between the side rails and across substantially the entire interior width thereof in spaced relation rearward of the front end of mobile frame  11 . Floating frame  30  includes front and side panels  32  and  34 . A pair of vertically adjustable ground engaging wheel assemblies  36  are mounted to opposed side panels  34  and provide the principal support for inner floating frame  30 . A hood  70  is connected between side panels  34  and will be described in more detail hereinafter. Front panel  32  is engaged in a trailing relationship to the front of mobile frame  11  and the front face of front panel  32  itself. Floating frame  30 , thus supported, will tend to float on wheel assemblies  36  to accommodate to any changes in ground contour. 
     Referring now to FIGS. 3-5, comminuting mechanism  10  further includes a comminuting apparatus  40  mounted within hood  70  supported by floating frame  30  between side panels  34  and immediately rearward of front panel  32 . Comminuting apparatus  40  includes a central drive shaft  42  preferably having a circular cross-section and spanning the width of comminuting apparatus  40  inside hood  70 . Alternatively, central drive shaft  42  may have a rectangular or hexagonal cross section  43  for substantially the entire length thereof providing a slip free engaging outer surface for mounting the blades on the drive shaft. 
     Comminuting apparatus  40  further includes a plurality of pulverizing blades  44  each comprising a central hub portion  46  having a central opening  48  and a plurality of blade arms  50  extend radially from hub portion  46  substantially in the plane of hub portion  46 . Pulverizing blades  44  further comprise a plurality of blade arms  54  having first portions laying in the plane of hub  46  and tip portions  56  angled in a first direction with respect to the plane of the hub, and a plurality of blade arms  58  having first portions  60  laying in the plane of hub  46  and second portions  62  angled in a second direction with respect to the plane of the hub. The blades are arranged around the circumference of the hub so that either a blade arm  54  or a blade arm  58  lies between each pair of blade arms  50 . Furthermore, the direction of blade arms  54  land  58  alternates around the circumference of the blade. Thus in a preferred embodiment, a blade arm  50  lying in the plane of the hub is followed by a blade arm  54  with its tip angled in a first direction, another blade arm  50  in the plane of the hub, and a blade arm  58  having its tip angled in the second direction with respect to the hub. This arrangement continues around each pulverizing blade  44 . Furthermore, adjacent ones of pulverizing blades  44  are mounted on shaft  42  in an axially and circumferentially offset arrangement so that a blade arm  54  is located between a pair of blade arms  50  and  58  on adjacent pulverizing blades. Pulverizing blades  44  are preferably manufactured out of metal, such as to steel, and may have a diameter of about 12 to 16 inches. 
     Pulverizing blades  44  are mounted on the drive shaft so that the rotation of the shaft rotates the blades. The alternating arrangement of arm tips  56 ,  62  provides for a wider pulverizing range for each blade along the central drive shaft  42 . It is preferable that the angled tip portions deviate from the plane of hub  46  by an angle of deflection θ of between about 130 to 170 degrees. 
     Each pulverizing blade  44  further comprises a plurality of airflow generating elements  64  fixedly secured along the trailing edge of straight arms  50  such as by welding. Airflow generating portions  64  are preferably disposed on alternating straight arms  50  on most if not all of pulverizing blades  44 . It should be appreciated that airflow generating portions  64  may also be disposed on the angled blade arms  54 ,  56  if desired. Each airflow generating portion  64  includes a flat portion  66  and an angled portion  68  attached to flat portion  66  at an obtuse angle. Furthermore, the obtuse angle faces in the direction of travel of the vehicle when the blade is proximate the ground and opposite to the direction of rotation of the blade. As will be explained hereinafter, airflow generating portions  64  create a positive airflow into the housing which helps draw debris into the housing where it is pulverized and then discharged to the rear of the vehicle. 
     Hood  70  arcs upwardly and rearwardly over the pulverizing units from the upper edge of an open mouth  72  to a rear discharge end  74 , and further spans the length of central drive shaft  42 . An arcuate plate  73  with a flat forwardly directed edge portion assists in scooping the ground debris through open mouth  72 . Arcuate plate  73  is preferably attached to side panels  34  at opposing sides. Hood  70  includes a pair of end panels  76  which are co-planar and attach to side panels  34  for attaching hood  70  thereto. Hood further includes a rectangular flap  78  secured to and extending from the edge of rear discharge end  74  assisting in the pulverized material in being directed toward the ground. A forward flap  75  overhanging slightly above open mouth  72  and preferably attached as an right angle to hood  70  helps direct air toward the rotating blades and keeps debris from being deflected forwardly. 
     In order to drive the comminuting mechanism, an appropriate power source, such as a gasoline engine  80 , is used. As illustrated, engine  80  can be mounted on an elevated platform  81  constituting a portion of mobile frame  11  rearward of the mechanism. Power transfer between engine  80  and central drive shaft  42  of comminuting apparatus  40  can be effected by one or more drive belts  82  engaged between a drive pulley  84  on engine  80  and drive pulley  86  mounted on one end drive shaft  42  beyond one of side panels  34  of floating frame  30 . 
     As will be appreciated, drive shaft  42 , at the drive end, will extend, utilizing appropriate bearing supports, through the corresponding side panel  34 . The opposite end of drive shaft  42  will be appropriately bearing supported in the opposed side panel  34  of floating frame  30 . 
     Referring to FIG. 2, a plurality of appropriate spring loaded idler pulleys  88  are used as required to maintain belt tension as the mechanism moves across the ground and accommodate itself to varying ground conditions. 
     Referring to FIG. 7, an alternative embodiment of pulverizing blade is illustrated at  144 . Here, similar or analogous features are labeled in multiples of 100. In this embodiment, it is contemplated that the tip of straight arms  152  be covered with carbide material  153  to enhance the durability of the blade arm. 
     Turning now to the operation of comminuting mechanism  10 , Was mobile frame  10  is moved along a path of travel by an appropriate towing vehicle, central drive shaft  42  is rotatably driven so that the blade arms  54  closest to the ground move in a direction opposite to the direction of vehicle travel (counter clockwise as viewed in FIG.  6  and shown by arrow  90 ). Drive shaft  42  and the pulverizing blades rotate at approximately 2800 rpm. Operating in this manner, it has been found that a positive air flow, produced by airflow generating portions  64 , in conjunction with the forward movement of the mechanism, effectively picks up and draws debris, including the plugs, balled thatch and the like through open mouth  72  and into hood  70 . Once through open mouth  72 , the debris is pulverized by the blades of the pulverizing units which quickly breaks the material down into small pieces. 
     The apparatus thus described, is considered to be a particularly significant addition to golf course grooming equipment in that it both reduces manual labor golf course down time and helps the environment as well. 
     While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration only, and such illustrations and embodiments as have been disclosed herein are not to construed as limiting to the invention as defined by the several claims appended hereto.