Abstract:
A leaf vacuum and mulching implement for attachment by three-point-hitch to a farm tractor and driven by mechanical connection to the tractor&#39;s power tack-off unit (PTO). The implement utilizes a broad vacuum deck having polymeric skirts in near proximity with the ground and a floating three-point-hitch system for lifting the vacuum deck and allowing it to follow the ground contour. High velocity fans blow debris collected by the vacuum deck to a unique, rotating, multifaceted, conical shredding rotor prior to directional dispersion.

Description:
SPECIFICATION 
     1. Field of the Invention 
     This invention relates generally to commercial leaf vacuum and mulching apparatus and more particularly to a tractor PTO driven leaf vacuum apparatus with mulching and directional dispersion capability attached to the tractor in a three-point hitch arrangement. 
     2. General Background 
     Large acreage, such as tree farms, orchards, and golf courses, are in constant need of maintenance due to fallen leaves, small twigs, etc. In addition to being unsightly, such debris tends to cover the ground, thereby retarding grass growth while producing a fire hazard. 
     It is well known that leaves and fine debris provide excellent mulch when broken down into fine particles, preventing evaporation of moisture, and adding humus to the soil. Therefore, it is advantageous for the leaves and fine debris to remain in and around trees provided their bulk can be broken down into very fine particles and dispersed evenly over the earth. 
     Various apparatus have been developed for collecting by seeping or vacuuming leaves and other such debris and reducing their particle size and re-depositing them back on the ground or into some type of towed container for transport and disposal at a remote site. 
     The prior art vacuum and/or mulching apparatus are generally associated with grass cutting mowers and are usually towable behind relatively small lawn type tractors and are self-powered. That is to say that most such apparatus have an onboard engine, thereby allowing for a flexible turning radius for the towed apparatus. Further, such mulching apparatus are generally associated with belly mowers located below the towing tractor type vehicle whereby the mulching system, having a blower for creating a vacuum, is connected to the belly mower of a lawn tractor by a large hose for collecting grass clippings, as well as leaves, stirred up by the mower&#39;s blade. The hose, as well as the mulching apparatus trailer, makes the system very hard to maneuver around trees and obstacles. A rotor located within the shredding apparatus having a plurality of flails or rotating blades serve to further shred the debris prior to disposition. However, although the need to reduce the debris into fine particles is recognized by the prior art, there is very little indication of just how fine the particles should be and very little agreement about how particle size reduction should be accomplished. Therefore, it is assumed that it is advantageous to reduce the debris to as small a particle size as possible, thereby making the debris virtually invisible when dispersed back on the ground. Many of the prior art mulching apparatus are incapable of such fine particle size reduction. 
     Devices that serve strictly as a vacuum type apparatus, such as those disclosed by U.S. Pat. Nos. 2,105,803, and 5,085,376 are towable or push type apparatus with onboard engines and rely on either the internal fan for both vacuuming and shredding the debris or a blower fan in combination with rotating spokes for shredding and expelling the debris. 
     The prior art, when taken as a whole, tends to teach the concept of collecting and dispersing leaves and twigs mostly combined with lawn clippings on a relatively small scale when time is not a factor but fails to address the need for speed and maneuverability over large acreage where man hours are limited. In such cases it is essential that a leaf mulching apparatus be efficient and adaptive to existing high-speed equipment, be capable of covering large acreage in a short time span, and also be highly maneuverable. 
     SUMMARY OF THE INVENTION 
     The instant invention is principally a leaf vacuum and mulching implement for attachment by three-point-hitch to a farm tractor and driven by mechanical connection to the tractor&#39;s power tack-off unit (PTO) or by a hydraulic motor driven by the tractor&#39;s auxiliary hydraulic system. The implement utilizes a broad vacuum deck having polymeric skirts in near proximity with the ground and a floating three-point-hitch system for lifting the vacuum deck and allowing it to follow the ground contour. High velocity fans blow debris collected by the vacuum deck into a unique, rotating, multifaceted, conical shredding rotor prior to directional dispersion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which, like parts are given like reference numerals, and wherein: 
     FIG. 1 is a frontal isometric illustration of the preferred embodiment of the mulching apparatus in operation; 
     FIG. 2 is a rearward isometric illustration of the preferred embodiment of the mulching apparatus in operation; 
     FIG. 3 is a frontal isometric view of the preferred embodiment of the mulching apparatus with cut-a-way view; 
     FIG. 4 is a partially exposed isometric view of the preferred embodiment of the mulching apparatus illustrated in FIG. 3 showing the drive system and fan cut-a-view; 
     FIG. 5 is a partially exposed isometric view of the preferred embodiment of the mulching apparatus illustrated in FIG. 4 showing the drive system and fan drive with one fan and duct assembly removed; 
     FIG. 6 is a vertical side view with partial cross section view of the particle sizing rotor assembly taken along sight lines  6 — 6  seen in FIG. 5; 
     FIG. 7 is an isometric view of the particle sizing rotor assembly; 
     FIG. 8 is a side view of the particle sizing rotor assembly; 
     FIG. 9 is an exploded view of the preferred apparatus seen in FIG. 1; 
     FIG. 10 is an isometric end view of the particle sizing, rotor housing with directional bell housing removed; and 
     FIG. 11 is an exploded isometric view of the particle sizing, rotor housing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As first depicted in FIG. 1, the vacuum mulching and dispersion unit is a farm implement adapted to any common farm tractor  12  for high-speed operation and maneuverability. The mulching apparatus is capable of vacuuming leaves and fine debris in large swaths of from 8 to 10 feet wide before mulching and dispersing the debris  11  back on the ground adjacent the mulching apparatus  10 . As seen in FIG. 2, the mulching implement  10  is attached to the tractor by a three-point-hitch arrangement  16  capable of lifting the implement clear of the ground for easy turn-around and is further fitted with a flexible upper connection element  18 , such as chain, commonly utilized in the art for allowing the implement to float or follow the contour of the ground. Adjustable height, swivel wheels  20  located at each corner of the vacuum deck  22  maintain ground clearance and further allow the mulching apparatus  10  to pivot as the tractor maneuvers around obstacles. 
     Looking now at FIG. 3 we see that the vacuum deck  22  is fitted with polymeric skirts  24  located below the deck  22  and extending the full width of the deck  22 , thereby providing a relatively large vacuum box below the deck  22 . Since no mower blades are utilized with this apparatus, a more positive vacuum can be maintained. Large fan ducts  26  draw debris from openings in the vacuum deck  22  into the intakes of twin high velocity induction fans  28  connected in tandem with their outlets connected to the rotor housing  30 . 
     Much of the drive mechanism is concealed by the cover  32 , seen in FIG. 3, and is therefore better seen exposed in FIG. 4. A drive shaft assembly  34  connectable to the output shaft of the tractor&#39;s PTO drive running at 540 rpm is connected to a gear box  36  having a 4 to 1 ratio, thereby increasing the gear box  36  output to 2,160 rpm. Pulleys attached to the gearbox&#39;s output shaft are then used to drive both the dual high velocity fans  28  at 5,220 rpm and the mulching rotor assembly  38 , seen in FIG. 7, at 2,160 RPM. The drive arrangement is best seen in FIG. 5 which illustrates a belt-driven series of pulleys utilizing a 50 percent pulley speed reduction that is utilized to drive the common fan shaft  40 , shown in cut-a-way with one of the fans removed. The output shaft of the gear box  36  is fitted with a dual pulley  42  having an 8-inch diameter pulley and a 4-inch diameter, the 8-inch pulley having a belt  46  connected to a 4-inch pulley located on fan shaft  40 . The 4-inch drive pulley is then connected by belt  48  through a system of idler pulleys in a right angle manner upwards to the rotor pulley  50 . 
     Leaves and other debris vacuumed from the ground by the high velocity fans are blown into the rotor housing  30 , seen in FIG. 6, where mulching takes place due to repeated contact with the conical-shaped multifaceted rotor assembly  38  prior to being discharged by a fan located in a fan housing or shroud  54  connected to the rotor housing  30  at flange  56 . The rotor assembly 38 sizes the materials passing through the rotor housing  30  to between approximately 50 micron up to one inch with the average size being approximately ¼ inch. The rotor housing  30  is a truncated conical shape and has a flattened portion near the truncation for making connection by flange mounting with the dual fan outlet ducts  58 . The fan ducts  58  to rotor housing connection is structurally sufficient to support the rotor housing  30  in a cantilever manner. 
     The rotor assembly includes a central shaft  60  supported within the rotor housing  30  by a flange bearing  62  at the upper or narrow end and by a collar bearing  64  and support member  66  connected diametrically across the opening at the wide or lower end. The central shaft  60  has a portion extending a distance beyond the collar bearing  64  where a fan blade assembly  52  is mounted thereon. 
     The rotor assembly  38 , as seen in FIG. 7, includes at least 4 elongated lattices  68  emanating from collars  67  attached to the central shaft  60  and bound by bands  70  and  71  holding the parallel bands  76  in compression. Each lattice  68  includes a doubling bar  72  having an offset portion  74  located at the wide or base end of the conical shaped lattice. Each lattice is composed of a series of horizontal bands  76  of approximately {fraction (3/32)} inch thick arranged with intersecting planes, which may not necessarily be at repetitive angles, as seen in FIG.  8 . The leading edges of each of the lattice bands  76  are sharpened, as seen in FIG. 8 a . The rotor assembly is rotationally balanced between shaft centers by adding lead weights as necessary, the process commonly known within the art. 
     A more detailed view of the major component parts is shown exploded in FIGS. 9,  10 , and  11 . In FIG. 9 we see the vacuum deck  22  fitted with the 4 swivel type wheels  20  located at each corner. Brackets  80  are provided for pivotal connection to the tractor  12  in three-point hitch arrangement whereby the tractor lifting arms  16  are capable of lifting the entire deck assembly  22  off the ground and whereby the clevis and chain assembly  18  provides for angular adjustment of the deck assembly, allowing the deck to pivot upwards at the trailing end but not allowing downward travel of the trailing end beyond a preset height established by the chain. Fan ducts  26  are mounted to the vacuum deck  22  over openings  27  therein and connect at their upper ends to the intakes of the high velocity fans  28 . The gearbox is mounted to the vacuum deck in a manner whereby the drive shaft  34 , seen in FIGS. 3 and 4, can easily make a sliding spline connection to the tractor&#39;s PTO output drive shaft. 
     As seen in FIG. 10, we see an end view of the rotor housing  30  in which a screen element  80  is inserted in the flange  56 . This provides a retaining baffle for the finely mulched leaves to collect behind prior to discharge to insure particle sizing as low as possible usually between 50 microns and 1 inch long. 
     In addition to the general rotor assembly  38 , as seen in FIG. 11, a directional nozzle housing  82  may be added for directing the fine particles downward or to either side of the tractor path if desired by simply orienting the nozzle  82 . 
     Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense.