Abstract:
An apparatus for cutting an edging trench around a landscape bed is constructed with a cutting blade that is rotated to help move the apparatus in the desired direction of travel while being operated to create an edging trench. The machine can be constructed in self-propelled, non-self-propelled or manually operated stick forms. The apparatus has a cutting blade that is configured in a cone-shaped manner with the narrow diameter located toward the center of the apparatus. The rotor is formed with a pair of thin slicing blades mounted on a spline shaft removable from the apparatus for maintenance. A first slicing blade shears the grass along the top of the trench and forms a vertical wall, while a second slicing blade forms a sloped wall. Displaced soil is discharged from the cutting blade and spread directly over the adjacent landscape bed to eliminate the need for subsequent clean-up operations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims domestic priority on U.S. Provisional Patent Application Ser. No. 61/959,839, filed on Sep. 3, 2013, the content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to edging devices used to create an small trench around a landscape bed, and more particularly, to a powered cutting assembly that is used to define the trench as a demarcation between different landscape areas, such as a landscape bed and grass areas, in which the rotation of the powered cutting assembly drives the apparatus forwardly. 
     BACKGROUND OF THE INVENTION 
     Edging devices are used to form a trench around the periphery of a landscape area to establish a line of demarcation between the landscape areas. For example, where lawns are adjacent to beds with flowers and/or bushes, and/or surround trees, a distinct dividing line can be formed around the periphery of the bed to create a distinct line of demarcation with respect to the lawn. Commonly, this line is defined by cutting a trench with a vertical wall at the edge of the lawn area. This trench restricts the spreading of grass from the lawn to the adjacent beds and also produces an aesthetically pleasing, sharp, dividing line between the different types of landscape. 
     The formation of these trenches around the periphery of landscape beds is commonly referred to as edging. Edging has been done in years past with conventional hand tools, such as flat-bladed shovels. While manual formation of trenches is desirable from a standpoint of flexibility and control, forming the trenches manually is labor intensive, requiring at least one worker slowly forming the trench. Thus, the manual formation of the landscape edging has a number of drawbacks. The slow manual formation of the edging trench typically requires the investment of many man hours, which typically dictates the need for a large work crew. This manual formation of the edging trench can be onerous when the work crew encounters dry and hard ground conditions, leading to significant worker fatigue. Furthermore, the manual formation of the edging trench usually results is an overall ragged appearance that does not precisely follow an intended course due to the incremental formation of the trench. Also, workers must deal with the material removed during trench formation. In a typical formation using a shovel, large chunks of terrain may be separated. These chunks either have to be hauled away or broken up manually to be distributed back into the bed. 
     As is shown in U.S. Pat. No. 2,555,441, granted on Jun. 5, 1951, to James G. Hackney, and in U.S. Pat. No. 2,737,105, granted on Mar. 6, 1956, to Aaron Wilson, edgers with powered rotating cutting assemblies have been developed for use in the landscaping industry to replace the manual process of forming edging trenches. Some edger cutting systems, such as disclosed in U.S. Pat. No. 6,857,481, issued to Johnny Hayes on Feb. 22, 2005, and in U.S. Pat. No. 6,092,608, granted on Jul. 25, 2000, to Herbert J. Leger, have a rotary, generally flat disc-shaped blade that penetrates the ground to produce an edging trench with spaced vertical walls. Such an edging device will cut large chunks of terrain that have to be either hauled away or broken up to be distributed back into the landscape bed. 
     In U.S. Pat. No. 4,002,205 issued on Jan. 11, 1977, to David C. Falk, and in U.S. Pat. No. 5,355,597, issued to Charles H. Pollard on Oct. 18, 1994, the powered trench cutting system is provided with a welded cutting member that includes a series of teeth strategically disposed to cooperatively produce a beveled or v-shaped trench. The toothed trench-forming blade in U.S. Patent Publication No. 2004/0251037 of David J. Templeton, published on Dec. 16, 2004, pulverizes the terrain that is removed from forming the trench and piles the removed terrain along the side of the trench to be manually distributed back into the bed without the need to be hauled away. 
     Both powered cutting systems have a frame structure with one or more wheels that facilitate controlled repositioning the edging apparatus over an adjacent surface of the ground. The operator can either manually pull the less expensive non-self-propelled version of the edging machine backwards along the periphery of the landscape bed to form the edging trench or the operator can walk forwardly when operating a more expensive self-propelled configuration of the edging machine, such as is disclosed in U.S. Pat. No. 5,156,218, granted to Dennis E. Metzler, et al, on Oct. 20, 1992. 
     While both of these types of powered cutting edgers overcome problems associated with manual trenching, the use of such powered edging devices also has some limitations and drawbacks. 
     First of all, the pull-backward edging machines, such as is disclosed in U.S. Pat. No. 7,096,970, granted on Aug. 29, 2006, to Roger D. Porter, et al, require the operator to pull the machine rearward, which is opposite to the direction that the blade rotation is trying to push the machine as the trench is being formed. Fighting the rotation of the cutting assembly causes premature operator fatigue. A similar problem is associated with the forward operating self-propelled machine, such as is disclosed in U.S. Pat. No. 6,883,616, issued on Apr. 26, 2005, to David J. Templeton, as this machine also has a cutting blade that pushes the machine in the opposite direction that the drive mechanism for the machine is moving the machine, thereby wasting engine power with opposing forces fighting against each other. 
     Both self-propelled and non-self-propelled trench forming machines are typically heavy implements, weighing between 125 and 400 pounds, which can cause transportation problems, particularly for rental centers, as the implement would require two or more people to lift the implement. These machines have a cutting system that utilizes multiple tooth blunt cutting blades to form the trench. When these blunt cutting blades encounter hard soil, tree roots and rocks, the rotation of the cutting system tends to raise the machine which tends to make the machine buck and jump relative to the ground. The solution to this problem is to make the machine heavy enough to keep the machine under control. Furthermore, these blunt tooth cutting systems have a cutting geometry that doesn&#39;t allow the cutter to slide up and over obstructions, as the teeth bite into the obstruction which magnifies the bucking and jumping problem. 
     Additional problems associated with the conventional powered edging machines is that for the non-self-propelled version, the machine is difficult to operate as the machine has to be pulled rearwardly forcing the operator to look rearwardly in order to walk, while being required to look forwardly to observe the machine cutting the edging trench. Accordingly, the non-self-propelled machine is uncomfortable and non-intuitive to operate. In the conventional powered cutting system, the throw path geometry of the pulverizing cutting blade soil distribution system throws the displaced terrain upwardly from the blade into engagement with a deflecting shield that first deflects the soil laterally and then deflects the soil downwardly to pile the soil along the side of the edging trench being formed. This displaced soil will need to be hand raked and spread out into the landscape bed, or alternatively removed, which requires an additional manual operation. 
     The problem of bucking a jumping of the machine when encountering obstacles is worse when the trench forming machine is pushed forwardly instead of being pulled backwardly. The operator can quickly lose control of the conventional trench forming machine when pushing in the same direction that the blunt cutting teeth of the rotor are pushing. Accordingly, the operator will have difficulty reacting quickly enough to change direction of the movement of the machine when an obstacle is encountered by the blunt teeth. By the time the operator realized an obstacle has been encountered, the trench forming machine has already thrust forwardly and possibly bucked sideways, thereby cutting in an unintended trench cutting path. Therefore, pulling conventional trench forming machine rearwardly puts the operator in a better position to react and maintain control of the operation of the machine since the operator is pulling the edger rearwardly. 
     Another problem associated with conventional powered trench cutting systems is the throw path geometry for the displaced soil from the edging trench. This pulverizing cutting blade soil distribution system does not deflect all of the displaced soil onto the bed adjacent the trench being formed. During the movement of the displaced, pulverized soil upwardly from the cutting blade, some of the soil will deflect out of the soil deflecting structure and land on the grass side of the trench. The unintentional displacement of the soil landing on the uncut grass terrain gives an un-finished look to the edging trench, which again requires re-distribution (clean-up) by hand-raking it over the edging trench and into the landscape bed through an additional manual operation. 
     The displaced soil throw path geometry of the pulverizing cutting blade soil distribution system on conventional powered cutting systems can have difficulty operating properly in wet soil conditions. Wet soil may cling and build up to the deflecting shields to a point of plugging the soil distribution throw path. When the throw path is plugged, the wet soil will build-up on the deflecting shields, which will then release as clumps of soil that later have to be broken up, then raked by hand into the bed in an additional operation. Alternatively, the wet soil will eventually accumulate on the deflecting shield to a point the deflecting shield completely plugs the machine, preventing any cut soil from being distributed from the cutting blade, which results in stoppage of the edging operation. 
     Conventional powered cutting systems, such as disclosed in U.S. Pat. No. 7,806,196, granted to Brent Peterson on Oct. 5, 2010, utilize blunt cutting teeth that pound the ground to penetrate, and then bulldozes through the terrain to displace soil and form the edging trench. Cutting an edging trench in such a blunt force operation requires excessive engine power, which is particularly onerous when the ground conditions are dry and hard. Furthermore, this blunt force type of cutting system also demands a heavy duty, and thus more expensive, drive mechanism to power the cutting blade. In addition, this blunt force trench cutting system requires the cutting blades to be disposed in a manner to produce a beveled or V-shaped edging trench. The blunt cutting teeth catch on every rock and tree root that might lie under the surface of the ground where the edging trench is to be formed. When the blunt cutting teeth hit on such obstructions, the teeth try to cut through the obstruction (possibly damaging the tree roots), but there is a tendency for the edger to “jump” randomly from the terrain during operation, potentially causing damage to the machine, injury to the operator, and imprecise trench formation, or at a minimum slow or even stop the edging operation. 
     The formation of a beveled or V-shaped edging trench requires the conventional powered trench cutting systems to orient the axis of rotation of the cutting implement somewhat parallel to the terrain surface. In some topographical circumstances, orienting the axis of rotation parallel to the ground results in a long reach for the extended cutting teeth to reach the surface of the ground past the bearing support structure, and then penetrate the cut distance into the terrain to reach the desired trench depth. The further the cutting teeth are from the bearing support, the longer the moment arm distance is away from the axis of rotation of cutting implement, which results in requiring more torque/power to form the edging trench. 
     Furthermore, the large soil deflecting structure needed for the conventional powered trench cutting systems to try to control the displacement of the soil from the edging trench being formed restricts the view of the operator and limits the ability of the operator to place the formation of the edging trench at exactly the location desired. Although the large soil deflecting shield is needed on conventional machines to deflect the displaced soil onto the bed adjacent the edging trench being formed and to prevent injury to the operator and others from flying debris, the large box shape of the soil deflecting shield is completely encloses the cutting blade system, which doesn&#39;t allow the operator good visibility to see where the blade is cutting the terrain. 
     Accordingly, it would be desirable to provide an apparatus for cutting an edging trench around landscape beds that had an improved system for displacing soil from the trench onto the ground adjacent the formed trench. It would also be desirable to provide a trench forming apparatus in which the cutting member was rotated in a direction that would facilitate the movement of the apparatus over the surface of the ground during operation in forming the edging trench. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to overcome the disadvantages of the prior art lawn edging machines by providing a terrain cutting system that has lower weight and a lower cost to manufacture, does not fatigue the operator during operation, cuts edging trenches using less energy, allows forward moving operation without the need of a self-propelled transmission, automatically and evenly spreads and distributes displaced soil to the bed without needing a second operation to clean the trench or spread the cut soil into the bed, does not damage tree roots and does not plug when cutting wet terrain. 
     It is a feature of this invention that the direction of rotation of the cutting blade assists the operator to push the machine forwardly. The edging trench forming machine according to the principles of this invention has the cutting blade rotating counter clockwise, when viewed from the center of the machine out. Rotating the cutting member in this direction helps to propel the machine forwardly during operation, greatly reducing the force required by the operator to push a non-self-propelled machine, sometimes to a point of having to hold the machine back. 
     It is another feature of this invention that the lower machine weight makes the trench-forming machine easier to lift, transport and operate. 
     It is another object of this invention to provide a powered rotating cutting member for an edging trench forming machine in which the rotation of the cutting member helps to propel the machine forward. 
     It is another feature of this invention to provide a cone-shaped cutting blade profile. The 360 degree cutting blade profile is cone shaped having a small diameter at one end and the larger diameter at the other. The small diameter end of the cone is toward the center of the machine. When the gearbox output shaft axis is horizontal or higher, the smaller diameter end of the cone is pointing either horizontally or somewhat toward the ground. At these angles, the cutting blade is normally in an inactive transport position. When output shaft axis is horizontal or lower with the larger diameter end of the cone pointing more toward the ground, the cutting blade is normally in an operating/working position. 
     It is an advantage of this invention that the edger apparatus has a high torque cutting geometry. When the gearbox pivots down to its working position, the rotary blade cutting circumference of the cone is theoretically cutting the more vertical surface of the V-shaped edging trench. The further the cutter pivots down the more vertical the circumference profile surface becomes. The geometry of having the cutting blade cone axis of rotation pointing downwardly and the blade circumference profile surface cutting the most vertical wall of the trench creates a much shorter cut moment arm to the rotary blade shaft axis. The result is angling the cutter axis downwardly to permit the use of a smaller diameter cutting cone profile as compared to current commercially available bededgers that use a horizontal axis in both operating and working positions. The smaller the blade cone diameter, the less torque/power required to cut the edging trench. 
     It is still another object of this invention to provide a forward operating direction control. When the cutter blade is in the operating position, straight forward machine movement is best controlled when the center point of the rotational axis at the larger diameter end of the cutting cone is located close to the ground surface. The deeper the center point goes below the ground surface, the more the contact with the ground wraps around the cutter cone circumference profile and changes the push geometry of the cutter blade away from just straight forward movement to pushing straight and sideways angling the directing of the machine. 
     It is another advantage of this invention that the edger apparatus doesn&#39;t plug or clump the soil cut from the trench formed by the edger apparatus. The displaced soil throw geometry is a very short throw distance with basically a straight path from the cutter blade to the bed. Centrifugal force moves the displaced soil away from the cutter along the inside of the trench cleaning plate, which wraps mostly around the cutter without any harsh deflecting turns, thus eliminating the potential of plugging or clumping the soil. The cutter blade evenly releases and spreads the soil directly into the bed without the need for a second operation to spread the soil over the landscape bed. 
     It is yet another object of this invention to provide a method of forming a clean trench and for spreading the displaced soil generated therefrom. To prevent the displaced soil from being thrown back into and re-filling the trench, the trench cleaning plate contains the cut soil close to the cutter circumference until it&#39;s at the right position for release to be thrown out and spread onto the bed. The way the cone shaped cutter blade enters the terrain and disburses the soil in cooperation with the tapered shaped trench cleaning blade that&#39;s partly positioned above and down in the trench does not allow any soil from getting on the grass side of the edging trench. 
     It is still another feature of this invention that the edger apparatus can include stacked replaceable cutting teeth. The bededging cutter blades can thus be individually replaceable, which are loosely stacked on a spline shaft for easy assembly and quick low cost maintenance for replacing worn-out teeth. Alternatively, the bededging cutter blades can be formed as a single weldment that provides cost savings for manufacturing, while allowing replacement of the cutting teeth. 
     It is yet another feature of this invention to provide a grass and soil slicing blade as part of the rotor assembly. The grass slicing blade is located at the small diameter end of the cutting cone profile and consistently and cleanly cuts the grass and root zone along the upper vertical edge of the edging trench. The slicing blade is a disc with a cutting side wall flange that angles down the outer surface of the cone profile surface. The side wall length is very short at the end that first engages the grass extending in length to the trailing end. This tapered cutting/slicing edge should be thin or even sharp to improve its grass cutting performance. The rotational geometry of the grass slicing blade slices into the ground using the uncut ground itself as a shear bar to cleanly cut the grass leaving a sharp edge to the vertical wall of the trench with a clean cut appearance to the grass at the top corner of the trench. 
     It is still another feature of this invention to provide a root protection blade. The cutting blade pulverizes the soil but rises up and over tree roots with minimal damage to the tree root. As described above, the tapered cutting/slicing edge cuts the soil and grass, but can&#39;t cut through solid objects like tree roots and just simply slides over them, which also helps to protect the drive line components of the machine. 
     It is yet another advantage of this invention that the edger apparatus can be utilized as a walk-behind unit. The walk-behind frame has a handle bar dashboard control mechanism that has an extended arm linked to the pivoting gearbox mounted on the lower frame for control of the position of the cutter from an inactive transport position to sidewalk edging and trench cutting positions. 
     It is a further object of this invention that the edger apparatus can be configured as a “stick” cutter assembly that pivots about a wheel axle raising the cutter assemble vertically up to transport position or down to operating position. 
     It is a further feature of this invention that the “stick” cutter embodiment of the invention utilizes a two axle frame using both axles in operating mode and the rear axle only to transport when the machine is not operating. 
     It is a further advantage of this invention to provide a trench forming apparatus that achieves control of a forward operating machine. 
     It is still a further feature of this invention that the cutting system utilizes long tapered cutting surfaces with at least one open area for each of the slicing blades to permit the slicing blades to gradually slice into the terrain to form the trench. 
     It is still a further advantage of this invention that the thin slicing blades do not generate as much rotor traction as conventional blunt tooth cutting systems during operation, thus allowing greater control over the operation of the trench forming machine. 
     It is yet a further advantage of this invention that the control over the operation of the trench forming machine does not require the addition of weight to the machine. 
     These and other objects, features and advantages are accomplished according to the instant invention by providing an apparatus for cutting an edging trench around a landscape bed is constructed with a cutting blade that is rotated to help move the apparatus in the desired direction of travel while being operated to create an edging trench. The machine can be constructed in self-propelled, non-self-propelled or manually operated stick forms. The apparatus has a cutting blade that is configured in a cone-shaped manner with the narrow diameter located toward the center of the apparatus. The rotor is formed with a pair of thin slicing blades mounted on a spline shaft removable from the apparatus for maintenance. A first slicing blade shears the grass along the top of the trench and forms a vertical wall, while a second slicing blade forms a sloped wall. Displaced soil is discharged from the cutting blade and spread directly over the adjacent landscape bed to eliminate the need for subsequent clean-up operations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a right, front perspective view of the edger apparatus with the rotor assembly lowered into an operative position; 
         FIG. 2  is a right, rear perspective view of the edger apparatus shown in  FIG. 1  with the engine being removed for purposes of clarity; 
         FIG. 3  is a rear elevational view of the edger apparatus with the rotor assembly lowered into an operative position, a representative discharge of material from the trench being formed by the rotor assembly being shown; 
         FIG. 3.5  is an enlarged partial upper, rear perspective view of the pivoting control panel moved into the inoperative transport position, the engine and other components being removed for purposes of clarity; 
         FIG. 3.6  is a top plan view of the rotor shield assembly and the trench cleaning plate and associated mechanism taken in alignment with the axis of rotation of the rotor assembly, the trench cleaning plate being shown in a raised position above the surface of the ground; 
         FIG. 3.7  is a top plan view of the rotor shield assembly and the trench cleaning plate similar to that of  FIG. 3.6 , but with the trench cleaning plate being shown in an operative lowered position within the trench being formed by the rotor assembly; 
         FIG. 3.8  is an orthogonal view relative to the view of  FIG. 3.7 , showing the trench cleaning plate in the operative lowered position rearwardly of the rotor assembly; 
         FIG. 4  is a rear elevational view of the edger apparatus similar to that shown in  FIG. 3 , but with the rotor assembly raised into an inoperative transport position, a representative trench formed by the rotor assembly being shown below the raised rotor assembly; 
         FIG. 5  is a partial right, rear perspective view of the pivoting control panel moved into the operative, trench forming position, the engine and other components being removed for purposes of clarity; 
         FIGS. 6 and 7  are perspective views of the rotor assembly; 
         FIGS. 7A-7D  are schematic sectional views of the rotor looking outwardly toward the distal end of the rotor to show the operation of the slicing blades of the rotor in a sequential manner with each of  FIGS. 7A through 7D  representing approximately a 90 degree rotation relative to the preceding view; 
         FIG. 8  is rear elevational view of the edger apparatus with the rotor assembly lowered into the trench forming operative position, the engine being removed for purposes of clarity; 
         FIG. 9  is a rear elevational view of the edger apparatus as shown in  FIG. 8 , but with the rotor assembly raised into the inoperative transport position; 
         FIG. 10  is a right front perspective view of the edger apparatus in operation to form a trench with the displaced soil being spread over the adjacent landscape bed; 
         FIG. 11  is a right front perspective view of a second embodiment of the edger apparatus, the rotor assembly being raised into an inoperative transport position; 
         FIG. 12  is a rear elevational view of the second embodiment of the edger apparatus with the rotor assembly in the raised transport position; 
         FIG. 13  is a rear elevational view of the second embodiment of the edger apparatus with the rotor assembly lowered into the operative trench forming position; 
         FIG. 14  is a partial left front perspective view of the second embodiment of the edger apparatus with the rotor assembly raised into the inoperative transport position; and 
         FIG. 15  is a partial left front perspective view of the second embodiment of the edger apparatus as seen in  FIG. 14 , but with the rotor assembly lowered into the operative trench forming position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to drawings and particularly to  FIGS. 1-10 , a first embodiment of an edging trench forming apparatus incorporating the principles of the instant invention can best be seen. Any references to left and right or front and rear are used as a matter of convenience and are determined by standing at the rear of the apparatus with the terrain slicing rotor  34  forming the edging trench positioned forwardly and along the right side of the machine. 
       FIG. 1  shows a perspective view of the gearbox pivot drop edger  10  (also referred to as the walk-behind bed edging machine) that consists of a main frame  12  that can be advanced controllably relative to subjacent terrain. The main frame  12  is preferably provided with three wheels, including two fixed wheels  26 ,  28  and a pivoting caster wheel  30  located rearwardly of the two fixed wheels  26 ,  28 . To create a zero turn steering the fixed front wheel  26  carries the least amount of weight to allow it to easily slide sideways when turning but still have enough weight to steer the edger in a straight line forward when desired to facilitate controlled repositioning. Caster wheel  30  and fixed wheel  26  have depth control mechanisms rear  38  and front  36  that raise or lower the right side of main frame  12  and terrain slicing rotor  34  to achieve the desired trench cutting depth. 
     Engine  14  is mounted to main frame  12  and has engine drive sheave  16  attached to engine  14  power take-off shaft  17 . Engine drive sheave  16  transmits power through drive v-belt  18  to gearbox sheave  20  which is attached to the gearbox input shaft  21  of gearbox  22 . Gearbox  22  transmits power from its rotating input shaft  21  to its rotating output shaft  23 , best seen in  FIG. 5 , to the terrain rotor slicing rotor assembly  34 . Gearbox  22  is pivotally mounted to main frame  12  on the gearbox input shaft  21  axis  74 . The operator can control the position to which the gearbox  22  is pivoted from the handle bar assembly  32  by manipulation of the control panel  40 , as will be described in greater detail below. The pivoting of the gearbox  22  controls the positioning of the terrain slicing rotor assembly  34  that is attached to the output shaft  23  of gearbox  22 . 
       FIG. 2  is a right, rear perspective view of the edger  10  without the engine being shown. A control panel  40  is mounted on the handle bar assembly  32 , attached to the upper end of shaft  42  that pivots on the tube axis  44  of the main frame  12 . A pivot arm  46  is attached to the lower end of shaft  42  to transfer pivotal movement of the shaft  42  through a link  48  which interconnects the pivot arm  46  at location  47  and the gearbox extension arm  50  to affect pivoting and positioning of the gearbox  22  and the rotating terrain slicing rotor  34  between an inactive transport position  54 , depicted in  FIG. 4 , and an active terrain trench cutting position  52 , depicted in  FIG. 3 . The terrain slicing rotor  34  consists of a slicing rotor blade assembly  56  having a 360 degree cone shaped cutting pattern  102  and being attached to the gearbox output shaft  23 , as best seen in  FIG. 5 . A rotor shield assembly  58  is attached to the gearbox  22 , with a trench cleaning plate  60  being pivotally attached to rotor shield assembly  58 . A flexible soil deflection flap  62  is also mounted to rotor shield assembly  58  to deflect displaced soil onto the landscape bed. 
       FIG. 3  is a rear view showing the terrain slicing rotor assembly  34  lowered into the terrain  64  in the active terrain trench cutting position  52 . As a result of the configuration of the terrain slicing rotor assembly  34 , the trench  68  is somewhat V-shaped having a vertical wall  70  and a slanted wall  72 . The slanted wall  72  has a curved shape due to the terrain slicing rotor  34  pivoting path in and out of the terrain brought about by pivoting on the gearbox  22  input shaft on axis  74 . The curved shape of the slanted wall  72  allows the terrain slicing rotor  34  to easily pivot up to inactive transport position  54 , as shown in  FIG. 4 , without trying to cut through terrain, which would be the case if the slanted wall  72  were straight. Arrows  71  show the discharge path of the cut or displaced soil when thrown from terrain slicing rotor  34  and landing in the bed  69 . 
       FIG. 3.5  is an enlarged perspective view of main frame  12  with terrain slicing rotor assembly  34  attached to gearbox  22 . The trench cleaning plate  60  is pivotally attached to a trench soil deflector pin  61 , which is attached to rotor shield assembly  58 . The connection between the trench cleaning plate  60  through the deflector pin  61  is loose, which allows a multi-directional movement of the trench cleaning plate  60  as shown by arrows  63 . The multi-directional movement of trench cleaning plate  60  allows the trench cleaning plate  60  to follow and float on the ever changing trench surface, particularly changes in the vertical depth of the formed trench. 
     Referring now to  FIGS. 3.5, 3.6, 3.7 and 3.8 , the trench cleaning plate  60  can best be seen. The purpose of the trench cleaning plate  60  is to trail behind the rotor  34  within the formed trench so that displaced soil is not conveyed from the rotor  34  rearwardly into the trench that has just been formed, and thus filling the formed trench. With the trench cleaning plate  60  positioned in the formed trench immediately behind the rotor  34 , the displaced soil is deflected out of the trench and unto the landscape bed. The trench cleaning plate  60  is connected by a spring  61   a  that biases the trench cleaning plate  60  into the formed trench. Because of the irregularities of a formed trench, particularly due to encountering obstacles, such as roots and rocks, the trench cleaning plate  60  needs to be able to move both laterally and vertically to maintain position within the formed trench. The biasing spring  61   a  and the loose connection of the trench cleaning plate by the pivot pin  61  permits this floating movement. 
     Preferably, the spring  61   a  is oriented such that the line of the spring  61   a  extends slightly upwardly as the spring  61   a  extends rearwardly, best seen in the side elevational view of  FIG. 3.8 , and also slightly inwardly toward the machine as the spring  61   a  extends rearwardly, as best seen in the top plan view of  FIG. 3.7 . The orientation of the spring  61   a  relative to the loose fitting deflector pivot pin  61  is such that the positioning of the trench cleaning plate  60  on top of the ground at the beginning of the operation of the edger  10  positions the line of the spring  61   a  next to the pin  61 , as best seen in  FIG. 3.6 , so that the moment arm of the spring force exerted by the spring  61   a  is small when the trench cleaning plate  60  is out of the ground, but spaced further away from the pin  61  when the trench cleaning plate  60  is positioned within the formed trench, as shown in  FIG. 3.7 . 
     Therefore, when the edger  10  is initiating the trench-forming operation, the rotor  34  and the trench cleaning plate  60  are located on the top surface of the ground in the orientation shown in  FIG. 3.7 . As the rotor  34  moves into the ground to form the trench, the trench-cleaning plate  60  remains on the surface of the ground, deflecting upwardly as the rotor  34  digs into the ground until the first part of the trench is formed and the rotor  34  and trench cleaning plate  60  or in the orientation shown in  FIG. 3.6 . The deflection of the trench cleaning plate  60  stretches the spring  61   a  and, as a result, increases the spring force exerted thereby. However, since the moment arm for the spring force decreases, the actual force exerted on the trench cleaning plate  60  does not increase, which enables the trench cleaning plate  60  to ease into the trench as the rotor  34  progresses forwardly in the formation of the trench. The net result is that the biasing spring  61   a  does not exert a large force on the trench cleaning plate  60  when the trench cleaning plate  60  is deflected to be positioned on the surface ground when the rotor  34  is in the trench, thus facilitating the movement of the trench cleaning plate into the trench even though a large spring force is being exerted on the trench cleaning plate  60 . 
       FIG. 4  shows a control panel  40  pivoted to a transport position and a clutch handle assembly  76  shown in a declutch position disengaging rotary power from the engine  14  to the terrain slicing rotor  34 . The clutch handle assembly  76  consists of a clutch pivot arm  78  pivotally attached to main frame  12  at location  79 , which is operable to translate pivot motion thereof through the link  80  to pivot an idler arm  82 , best seen in  FIG. 1 , which is pivotally attached to the main frame  12  at pivot location  84 . The idler sheave  86  is attached to the pivot idler arm  82 . When the clutch pivot arm  78  is pivoted upward to the handle bar  88 , as shown in  FIG. 1 , the idler sheave  86  pivots down into engagement with the drive v-belt  18 , tightening the v-belt  18  around engine drive sheave  16  and thereby allowing rotational power from the engine  14  to be transmitted through the v-belt  18  to drive the rotation of the terrain slicing rotor  34 . 
       FIG. 5  is an enlarged perspective view without the engine  14 , rotor shield assembly  58  and trench cleaning plate  60 .  FIG. 6  and  FIG. 7  are opposing perspective views of the terrain slicing rotor  34  with the 360 degree cone shaped cut pattern  102  removed to better view the details of the rotor  34 . The terrain slicing rotor  34  is formed with a first slicing blade  90  that upon rotation forms the vertical wall of the trench with the slice cutting edge  92 . A second slicing blade  94  is located at the distal end of the rotor  34  and forms upon rotation the slanted wall of the trench with the slice cutting edge  96 . Both of the first and second slicing blades  90 ,  94  are attached to the rotor shaft  98  so as to be rotatable therewith. The terrain slicing rotor  34  is slideably attached to the gearbox output drive shaft  23  through the connecting hub  100  to permit the rotor  34  to be removed for service or replacement. 
     The operation of the rotor  34  is reflected in the cross-sectional views  7 A- 7 D taken parallel to, or along the line of, the axis of rotation of the rotor  34 . As can be seen in  FIGS. 7A through 7C , the first slicing blade  90  first engages the surface of the ground G with the cutting edge  92  in a slicing or scissors action that increases the depth of the first slicing blade  90  into the ground as the rotor  34  rotates. After about 360 degrees of rotation, as shown in  FIG. 7A , the trailing end  91  of the first slicing blade  90  exits the ground G as the forward cutting edge  92  starts to engage the ground G. The trailing edge  95  of the second slicing blade  94  exits the ground G, as seen in  FIG. 7C  at about the same time as the trailing end  91  of the first slicing blade  90  enters the ground G. The forward edge  96  of the second slicing blade  94  engages the ground G with a similar slicing or scissors-like action, as seen in  FIG. 7D , that increases in depth as the rotor  34  rotates, as seen in  FIG. 7A  until the trailing edge  95  of the second slicing blade  94  exits the ground, as depicted in  FIG. 7C . 
     As a result, a balanced cutting action is accomplished by the rotor  34 , reducing the power required to form the trench. With each rotation of the rotor  34 , a portion of the vertical wall  70  of the trench  68  is formed by the first slicing blade  90  followed by the formation of a portion of the sloped face  72  of the trench  68  by the second slicing blade  94 . With each slicing blade  90 ,  94  engaging the ground in a slicing manner resulting in a progressively increasing depth of the slicing blade  90 ,  94  into the ground, less power is required than in the conventional trench forming machines that impact the ground with brute force. 
     One skilled in the art will recognize that the thin slicing blades  90 ,  94  do not bluntly impact the ground, as is known in conventional prior art edging machines, but instead slice into the ground with a tapered cutting edge  92 ,  96  that minimizes the amount of force required to form the trench. Since the first and second slicing blades  90 ,  94  are relatively thin, i.e. preferably less than a quarter of an inch thick, and are substantially continuously engaged in the ground with first one slicing blade  90 ,  94  and then the other slicing blade  90 ,  94 , the amount of horsepower required to rotate the rotor  34  and form the trench is substantially less than has been conventionally known in the art. As noted elsewhere within this specification, the rotation of the first slicing blade  90  forms the vertical wall of the formed trench, while the second slicing blade  94  forms the slanted or curved wall of the formed trench. 
     Furthermore, the operation of the thin slicing blades  90 ,  94  keeps the edging machine  10  from jumping when hitting an obstacle in the ground while the rotor is forming the trench. The thin slicing blades  90 ,  94  will slide upwardly over the obstacle, slightly raising the edging machine  10 , until the obstacle has been cleared, as opposed to conventional edging machine bluntly pounding the obstacle with brute force, which tends to make conventional edging machines jump vertically, depending on the weight of the edging machine. Accordingly, the instant edging machine  10  does not require a large mass to keep the machine  10  stable. 
     Referring now to  FIGS. 8 and 9 , the movement of the terrain slicing rotor  34  between the raised inoperative transport and the lowered trench forming positions can best be seen. Both  FIGS. 8 and 9  depict a rear view of the edger  10  with the engine  14  and trench cleaning plate  60  removed for purposes of clarity. The terrain slicing rotor  34  is lowered into active terrain trench cutting position  52  in  FIG. 8  and raised into the inactive transport position in  FIG. 9 . During rotation, the terrain slicing rotor  34  forms a 360 degree cone shaped cutting pattern  102 , the rotor  34  rotating counter clockwise, as shown by the arrow  103  in  FIG. 5 , when viewing outwardly from the center of the machine toward the distal end of the rotor  34 . The cone shaped cutting pattern  102  has a smaller diameter cone end positioned closer to the gearbox  126  and a larger diameter cone end positioned further away from the gearbox  126 . 
     When the axis  104  of the output shaft  23  is oriented horizontally, as depicted in  FIGS. 8 and 9  by the center line  107 , or is angled below horizontal, the largest diameter portion of the cone shaped cutting pattern  102  is positioned close to or located in the terrain and the rotor  34  is considered to be in an operating/working position. Point  105  is defined as being located at the intersection of the section plane  106  of the cone shaped cutting pattern  102  and the axis  104 . When the terrain slicing rotor  34  is at full cutting depth, the terrain slicing rotor  34  is positioned with intersection point  105  on or slightly above the top surface of terrain  64  at location  105 . If the terrain slicing rotor  34  is positioned with the intersection point  105  below the top surface of the terrain  64 , the rotary cutting forces created by the terrain slicing rotor  34  engaging with the terrain start to steer the machine  10  more to the side instead of moving straight ahead. Conversely,  FIG. 9  shows the edger  10  with the axis  104  of the gearbox output shaft  23  is oriented horizontally, or angled higher than horizontal  107 , to position the rotor  34  in an inactive transport position  54 . 
     The operation of the edger can be seen in  FIG. 10 , traveling forward as shown by direction arrow  108 . Direction arrow  110  shows the counter clockwise rotation direction of the 360 degree cone shaped cut pattern  102  of the terrain slicing rotor  34 . Arrow  112  depicts the movement of the displaced soil being thrown out and away from the terrain slicing rotor  34  and the trench cleaning plate  60  into the landscape bed  69 . 
     A second embodiment of the edger  113 , which can be referred to as a Stick Bededger, can be seen in  FIGS. 11-15 . The edger  113  has a different geometry for lowering the terrain slicing rotor  34  from the inactive transport position  138  above the terrain, as shown in  FIGS. 12 and 14 , to the active terrain trench cutting position  140  located down in the terrain, as shown in  FIG. 13 , as will be described in greater detail below. The axle pivot drop edger  113  has a main frame assembly  119  pivotally attached to the axle frame assembly  115 , which moves in the direction of travel during operation shown by directional arrow  111  in  FIG. 15 . The main frame assembly  119  can be pivotally advanced controllably into the terrain relative to the axle frame assembly  115 . 
     The axle frame assembly  115  includes an axle frame  125  having a rear axle shaft  123  and a front axle shaft  114  attached thereto. The rear axle shaft  123  has two wheels  121  attached at opposing ends of the rear axle shaft  123 , and the front axle shaft  114  has a single wheel  121  attached thereto. A latch  128  is pivotally attached to axle frame  125  at a pivot hub location  130  and has the function of latching the pin  136 , which is attached to the main frame assembly  119  to hold the main frame assembly  119  up in the inactive transport position  138 , as shown in  FIG. 12 . 
     The main frame assembly  119  includes a gearbox  120  attached to pivoting gearbox frame  118 , which in turn is pivotally attached to front axle shaft  114 . A power unit  117 , preferably including a gasoline engine  124  of the type commonly used to power hand-held grass trimmers, is mounted at the proximal end of the main frame assembly and is attached to the gearbox input shaft  122  to supply rotational power to the gearbox  120 . The terrain slicing rotor  34  is connected to the gearbox output shaft  126  of the gearbox  120 . The main frame assembly  119  is supported at the power unit  117  by the edger operator who can manually pivot the main frame assembly  119  between the raised transport position  138  and the lowered trench cutting position  140 . 
     The main frame assembly  119  can latch up in the inactive raised transport position  138  by raising the main frame assembly  119  upwardly to be automatically latched by pivoting latch  128  connecting to a pin  136  attached to gearbox frame  118 , best seen in  FIG. 14 . The pivoting latch  128  is biased forwardly into a latch position by the spring  127  which extends between the pivot latch  128  and the axle frame  109 . To unlatch and lower main frame  119 , the operator steps on the rear tread portion  134  of latch  128  to pivot the latch  128  away from pin  136 , allowing the main frame  119  to be lowered to the operative trench cutting position, as shown in  FIG. 15 . 
     The terrain slicing rotor  34  operatively connected to the gearbox  120  is angled down from horizontal gearbox centerline  144  so that when it is at full cutting depth the terrain slicing rotor  34  is positioned with intersection point  105  on or above the top surface of terrain  64  at location  105 . As noted above with respect to the first embodiment of the edger  10 , if terrain slicing rotor  34  is positioned with the intersection point  105  below the top surface of terrain  64 , the rotary cutting forces of the terrain slicing rotor  34  engaging with the terrain start to steer the machine  113  more to the side instead of straight ahead. The terrain slicing rotor  34  of the axle pivot drop edger  113  is exactly the same assembly and has substantially the same operative function as the first embodiment of the edger  10  described above in conjunction with  FIGS. 5-7  except that the trench is not formed with a “curved shape” slanted wall  72  created when raising the terrain slicing rotor  34  out of the terrain  64 . The pivot geometry of the axle pivot drop edger  113  allows for the formation of a straight slanted wall which lessens the amount of soil being cut by the rotor  34  and the power required to do so. 
     Operation Description 
     To operate the gearbox pivot drop edger  10  (also referred to as the Walk-behind Bededger), the engine  14  is started to provide operative power to the terrain slicing rotor  34  to dig a vertical face  70  and sloped face  72  trench as shown in  FIG. 3 . To start rotation of the terrain slicing rotor  34 , the operator depresses clutch handle  78  by pivoting the handle  78  toward the handlebar  88 , as shown in  FIG. 3 , which then lowers the idler  86  into engagement with the v-belt  18 , placing tension on the v-belt  18  to allow the power take-off sheave  16  of the rotating engine  14  to transfer rotational power from the engine power take-off shaft  17  to the gearbox  21  and, thereby, rotate the terrain slicing rotor  34 . At the start of operation of the edger  10 , the trench cleaning plate  60  is positioned on top of the ground behind the rotor  34 . 
     The operator then pivots the control panel  40  clockwise, as shown in  FIG. 3 , to move into the trench edging operating position which lowers the terrain slicing rotor  34  into engagement with the terrain  64 . The operator then, with assistance from rotation of the terrain slicing rotor  34 , pushes the gearbox drop edger  10  forward along a desired path of travel to form a spatial extent of a trench. As the rotor  34  is forming the beginning of the trench, the slicing blades  90 ,  94  engage into the ground discharging the displaced soil outwardly onto the landscape bed. As the edger  10  advances forwardly, the trench cleaning blade  60  moves into the formed trench due to the biasing force exerted by the spring  61   a  until the trench cleaning plate  60  is fully inserted into the trench to deflect the displaced soil out of the trench as the edger  10  progresses forwardly. 
     Trench depth into the terrain  64  is controlled by either adjusting the length of link  48  between the pivot arm  46  and the gearbox extension arm  50  or by adjusting the height of the caster wheel  30  and the fixed wheel  26  using depth control mechanisms rear  38  and front  36 . Adjusting the amount of distance that the flexible soil deflection flap  62  hangs out over rotor shield assembly  58  regulates the distance and thickness the soil is discharged from terrain slicing rotor  34 . Soil displacement can be adjusted from a wide thin layer spread pattern that&#39;s thrown out into the landscape bed  69  to a narrow, but much thicker soil mound that&#39;s positioned alongside the formed trench. 
     To operate the axle pivot drop edger  113  (also referred to as the Stick Bededger), the engine  124  located on power unit  117  is started. To provide operative power to the terrain slicing rotor  34 , the operator depresses the clutch handle  148  located on power unit  117  to engage the drive and transfer rotational power to the gearbox  120  for rotation of the terrain slicing rotor  34 . The operator then steps on rear tread portion  134  of the latch  128 , best seen in  FIG. 14 , to unlatch the main frame assembly  119  from being held up by the axle frame  115  on the pin  136  and lower the main frame assembly  119  with the terrain slicing rotor  34  into the operating position. The rotor  34  can then form a trench in the terrain  64  with a vertical face  70  and a sloped face  72 , as depicted in  FIGS. 13 and 15 . The operator then, with assistance from the rotation of the terrain slicing rotor  34 , pushes the axle pivot drop edger  113  forwardly along a desired path of travel and form a spatial extent of a trench. 
     To successfully achieve forward operating advancement without the use of a self propelled transmission that controllably drives the apparatus  10 ,  113  forwardly, several key functional elements are needed to prevent the apparatus from hopping upwardly, jumping forwardly or steering off to the side instead of going the direction the operator desires when steering the apparatus to cut the desired trench outline surrounding the bed  69 . Forward operation key functional elements start with the terrain slicing rotor  34 . The direction of the blade rotational, which has the leading edge of the first slicing blade moving into engagement with the terrain  64 , helps to assist the operator in pushing the apparatus forwardly. 
     To accomplish this and achieve maximum operator control of the forward movement and travel direction of the apparatus  10 ,  113 , the terrain slicing rotor  34  has a 360 degree cone shaped cutting pattern  102  that rotates counter clockwise shown by arrow  103  in  FIG. 5 , when viewing out from the center of the machine toward the distal end of the rotor  34 . The cone shaped cutting pattern  102  of the terrain slicing rotor  34  has the smaller diameter cone end positioned closer to gearbox  126  and the larger diameter cone end positioned further away from gearbox  126 , so when the terrain slicing rotor  34  is at full cutting depth the terrain slicing rotor  34  is positioned with intersection point  105  on or above the top surface of terrain  64 . If the terrain slicing rotor  34  is positioned with intersection point  105  below the top surface of terrain  64 , the rotary cutting forces of the terrain slicing rotor  34  with terrain  64  start to steer the machine more to the side instead of straight ahead. 
     Another forward operation key functional element of the terrain slicing rotor  34  is the thin sloped, or tapered, slicing blades. The terrain slicing rotor  34  has a first thin slicing blade  90  for forming the vertical wall of the trench with the sloped slicing cutting edge  92 , and a second slicing blade  94  for forming the slanted wall of the trench with the sloped slicing cutting edge  96 . Both the first and second slicing blades  90 ,  94  are mounted on the rotor shaft  98  for rotation therewith. 
     The thin sloped shape of these slicing blades  90 ,  94  easily slice and penetrate into the terrain  64  minimizing the opposing negative recoil reaction of hopping, jumping forward or steering off to the side when cutting into hard tough soil conditions or obstructions in the terrain  64 , such as large rocks or tree roots which have the potential of creating unsafe conditions for the operator. Basically, the sloped slicing cutting edge  92  of the first slicing blade  90  slices through most all soil conditions, but when the first slicing blade  90  comes in contact with obstructions in the terrain  64 , such as large rocks or tree roots, the blade  90  gently slides up and over the obstructions without grabbing or getting caught and, thereby, causing the apparatus to start bucking and jumping forward or steering off to the side. 
     Another forward operating advancement key functional element of the terrain slicing rotor  34  is the cutting characteristic of the thin trench vertical wall slicing blade  90  with the sloped slicing cutting edge  92  is so efficient in cutting the trench that less weight is required to hold the apparatus on the ground during operation. This in turn allows the apparatus to be lighter in weight then other comparable known bededgers and easier for the operator to push. Further, the direction of rotation of the slicing blades  90 ,  94  advances the cutting edge  92  forwardly into the terrain which pulls the edger  10 ,  113  in the forward direction of movement in the formation of the trench, as opposed to conventional edging machines that have to be pulled rearwardly forcing the operator to look rearwardly in order to walk, while being required to look forwardly to observe the machine cutting the edging trench. 
     The depth at which the trench is formed into terrain  64  is controlled by the operator rotating and then locking the depth control plate  150  on the pin  136  to a desired depth controlling position. The eccentric shape of depth control plate  150  allows for different distance adjustments extending out from pin  136 . So when main frame assembly  119  with the depth control plate  150  attached is unlatched from latch  134  and lowered onto the axle frame  125 , the rotary position of the depth control plate  150  positions the main frame assembly  119  relative to axle frame  115  to cut the desired trench depth into the terrain  64 . The trench cleaning plate  60  guides the cut soil out of the trench, delivering the displaced soil to the bed  69  and keeping the trench clean after cutting the trench. The cut geometry of the terrain slicing rotor  34  softly throws the soil directly out of the trench and onto the landscape bed  69  automatically spreading the displaced soil over the surface of the bed  69 . 
     It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.