Abstract:
A mini shrub spader for unearthing and transporting trees and shrubs. The mini shrub spader has a basketed U-blade which allows it to unearth, shape the root ball and transport a tree or shrub utilizing the same device. The mini shrub spader is preferably mounted to the rear of a small tractor.

Description:
FIELD 
     This invention relates to a mini shrub spader for unearthing and transporting trees or shrubs. 
     BACKGROUND OF THE INVENTION 
     The ability to easily and quickly unearth and transport shrubs and trees is essential to success in the nursery industry. Typically, the devices used to unearth shrubs and trees are large and complex, making them difficult to maneuver in the tight spacing between rows of nursery plants. These large devices are further flawed in that they often do not shape the root ball and may damage the roots and/or trunk resulting in plant mortality. Moreover, once unearthed, typically the plants must be manually transferred to another device to be transported to their ultimate destination. 
     U.S. Pat. No. 2,770,076 issued Nov. 13, 1956 to Kluckhohn discloses an apparatus for removing and transporting trees comprising a U-shaped cutter mounted onto a front-end loader or similar machine. To remove and transport a tree, the U-shaped cutter is submerged into the earth some distance from the target tree. The U-shaped cutter is advanced towards the target tree until it is directly under the target tree. At this point the boom of the front-end loader, or similar machine, is raised vertically and the target tree, together with the dirt surrounding the roots, is removed from the ground. Due to the size of the apparatus disclosed by Kluckhohn and its method of operation, this apparatus is impractical for use in a nursery. Further, the apparatus disclosed by Kluckhohn does not shape the root ball of the unearthed tree or shrub requiring additional labour and expense. The Kluckhohn device also does not cut through all of the roots resulting in tearing of uncut roots when the target tree is lifted, thus damaging the roots. 
     U.S. Pat. No. 4,979,321 issued Dec. 25, 1990 to Hall discloses a tree excavator comprising an excavator scoop mounted on the articulating crane arm of a truck. The excavator scoop comprises a plurality of curved segments mounted for movement between a nested position and a deployed position. Again, the size of the tree excavator disclosed by Hall makes it impractical to use within the tight row spacing of a typical nursery. 
     U.S. Pat. No. 5,133,268 issued Jul. 28, 1992 to Delisle discloses a tree scooper mounted to the standard hydraulically articulated beam of a tractor by way of an H-mount. The tree scooper comprises a scoop with a shovel shaped bottom and two sides. The leading edge of the scoop has angled teeth. The movement of the scoop is powered by four hydraulic cylinders; two hydraulic cylinders mounted internally within the H-mount and two hydraulic cylinders mounted with one on each side of the scoop. To unearth a tree or shrub, the tree scooper combines a rotating and back-sliding action to allow the scoop to travel in a semi-circular path under a tree or shrub. The moderately sized tractor with a standard hydraulically articulated beam required to mount the tree scooper disclosed by Delisle limits the tree scooper&#39;s mobility and practicality in the narrow aisles of a nursery. Delisle&#39;s tree scooper also suffers from the inability to transport a tree or shrub once unearthed thereby requiring additional time, effort and expense. Moreover, the operation of the tree scooper disclosed by Delisle is complex requiring the user to coordinate the sliding and rotating actions of the tree scooper in order to achieve a satisfactory result. 
     U.S. Pat. No. 5,762,146 issued Jun. 9, 1998 to Andrews discloses a nursery plant digger designed to remove plants, grown in long parallel rows, from the soil and to remove the soil from the roots. The nursery plants digger comprises a horizontally aligned bar mounted to the rear of a tractor and having a U-shaped scoop mounted to the distal end of the bar. The scoop travels through the soil, slightly under the plant, thereby lifting the plant from the soil. The uprooted plants are transferred to a shaking grate located behind the scoop which shakes the soil free from the roots. The plants are then deposited in the field for easy pickup. The nursery plant digger disclosed by Andrews can not transport the plants once unearthed. Further, Andrews&#39; device removes the soil from the roots of the plants making it inappropriate for use with trees or shrubs that require the root ball remain intact. 
     It is, therefore, an object of this invention to provide a mini shrub spader capable of unearthing, shaping the root ball of, and transporting a tree or shrub relatively easily and quickly within a nursery environment. 
     It is a further object of this invention to provide a mini shrub spader which is light in weight and compact in design. 
     SUMMARY OF THE INVENTION 
     The mini shrub spader of this invention is constructed of a steel frame which houses the hydraulic systems. The frame is H-shaped having a basketed U-blade pivotally secured to the front of the frame. The U-blade is actuated through two hydraulic cylinders mounted on the top of the frame. The rear of the frame has a three-point hitch to allow the mini shrub spader to be secured to a small tractor or similar towing device. The hydraulic systems of the mini shrub spader are powered through either the external hydraulics or the power transfer outlet of the towing vehicle. 
     To operate the mini shrub spader to unearth a tree or shrub, first, the basketed U-blade is placed in the pre-digging position adjacent to the target plant to be dug. The basketed U-blade then moves in a semi-circular path, cutting under the target plant and through the bottom portion of its roots, digging it up, shaping the root ball and supporting the target plant, and its root ball, in the basket of the basketed U-blade. 
     The basketed U-blade of the mini shrub spader may be interchanged with basketed U-blades of various sizes and shapes corresponding to the size and species of plant to be unearthed and transported. 
     Other objects and advantages of the invention will become clear from the following detailed description of the preferred embodiment, which is presented by way of illustration only and without limiting the scope of the invention to the details thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention itself both as to organization and method of operation, as well as additional objects and advantages thereof, will become readily apparent from the following detailed description when read in connection with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of the mini shrub spader with the basketed U-blade in the post-digging/transporting position; 
     FIG. 2 is a side view of the mini shrub spader with the basketed U-blade in the pre-digging position; and 
     FIG. 3 is a side view of the mini spader with the basketed U-blade in the post-digging/transporting position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Throughout the figures, like elements are indicated by like reference numbers. Referring to FIG. 1, the mini shrub spader  10  includes an H-shaped frame  12  which houses the hydraulic systems  32 . Frame  12  is comprised of two parallel frame members  14  and a cross member  16  located between and secured firmly to the frame members  14 . Slidably and pivotally mounted to the outside of the frame members  14  are the support legs  24 . 
     The basketed U-blade  18  is pivotally mounted onto the front of frame  12  through pivot  50 . The basketed U-blade  18  is comprised of a basket  20  comprising a set of parallel arcuate ribs attached at one end to a rear of a U-shaped blade  22 . The leading edge of the blade  22  is sharpened to efficiently cut through the ground under the target plant. 
     The basketed U-blade  18  is operatively coupled to hydraulic cylinders  26  through elbows  28 . At one end, elbows  28  are pivotally coupled to the basketed U-blade  18  at pivots  52  and at the other end, secured to hydraulic cylinders  26 . The ends of hydraulic cylinders  26  that are not secured to elbows  28  are pivotally coupled to cylinder mounts  34 . Hydraulic cylinders  26  are powered by hydraulic systems  32  which are operatively coupled to a power transfer outlet or external hydraulics of a towing vehicle (not shown) through power transfer conduit  30  (see FIG.  2 ). 
     Referring to FIGS. 2 and 3, mounted at the rear of the frame  12  on the underside of frame members  12  are the mounting members  48  with hitch mounts  42 . A back plate  36  is mounted onto the rear of the frame  12 . Secured to the top of the back plate  36  is the hitch bracket  40 . The combination of the hitch bracket  40  and the hitch mounts  42 , forms a three-point hitch  38  allowing the mini shrub spader  10  to be mounted onto the rear of a tractor or similar towing vehicle. 
     In operation, the mini shrub spader  10  is secured to the rear of a tractor or similar towing device through the three-point hitch  38 . With the basketed U-blade  18  in the pre-digging position, the towing vehicle is used to position the mini shrub spader  10  adjacent to the target tree or shrub such that the trunk of the target tree or shrub is aligned centrally between the blade pivots  50 . Once in position, through control lever  46 , the hydraulic cylinders  26  are actuated and the basketed U-blade  18  moves in a semi-circular path, cutting under the tree or shrub, and digging it up until the basketed U-blade  18  reaches the post-digging position (see FIG.  3 ). The basketed U-blade  18  is designed such that the forward portion of the basket  20  follows the path of the blade  22  under the tree or shrub to minimize disruption of the root ball while the rear portion of basket  20  lifts up the root ball slightly as it passes underneath it. In the post-digging position, the basket  20  of the basketed U-blade  18  supports the root ball of the tree or shrub which can then be easily transported to be wrapped in burlap or placed in another location for planting. 
     It will be appreciated by those skilled in the art that the mini shrub spader of this invention is distinguished by its versatility, simplicity, and efficiency. Moreover, the design of the mini shrub spader precludes the need for manual labour and a separate device to transport the unearthed tree from the location at which it was unearthed. 
     Furthermore, it will be understood that the hydraulic cylinders, hydraulic systems, etc. used throughout this invention may be of any desired design according to the knowledge of those skilled in the art and operate in conventional fashion to achieve the intended result. Indeed, the hydraulic cylinders may be replaced with electric or pneumatic equipment, if so desired. 
     Although the present invention has been described in detail with reference to one preferred embodiment, it will be clearly understood that this is by way of illustration only. Many variations and alternative embodiments of the invention will now be apparent to those skilled in the art, and are not to be excluded from the scope of the invention, which is to be determined only by the appended claims, as set forth below.