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CROSS-REFERENCED TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates to buckets used with work vehicles. More specifically, this invention relates to multi-purpose buckets used with work vehicles. 
     II. Related Art 
     Various work vehicles exist in the art. Such work vehicles include, without limitation, skid-steer loaders, back hoes, excavators, power shovels, front end loaders, tractors and the like. A variety of bucket attachments have been developed for use with such vehicles. However, such buckets typically are designed for a single purpose. 
     For example, some buckets are designed for excavating. See U.S. Pat. No. 6,546,650 to Meurer. Others are designed for grading. See U.S. Pat. No. 6,662,478 to Virnig. Still others are designed for digging. See U.S. Pat. No. 4,028,823 to Edwards et al; U.S. Pat. No. 5,018,283 to Fellner and U.S. Pat. No. 3,478,449 to Baker. Some are designed for dislodging (or moving) rocks, stumps and other large and bulky debris. See U.S. Pat. No. 6,098,320 to Wass and U.S. Pat. No. 4,607,441 to Norton. Others are designed for scooping and lifting. See U.S. Pat. No. 3,807,587 to Maurer. Still other are adapted for sue in hard materials such as rock strata, caliche, soapstone and plastic soils such as clay. See U.S. Pat. No. 4,476,641 to Ballinger. Some buckets are designed for ripping and trenching applications. See U.S. Pat. No. 4,616,433 to Knell et al. Still other buckets are designed for scraping or leveling the ground. See U.S. Pat. No. 7,562,473 to Westendorf et al; U.S. Pat. No. 6,434,863 to Meurer and U.S. Pat. No. 6,910,290 to Meurer. 
     The specialized nature of bucket attachments forces owners and operators of work vehicles to make a choice. They have to decide whether the work vehicle will be used for a single purpose or whether the work vehicle will be used for multiple purposes at various job sites. If the work vehicle is equipped with a single specialized bucket, several work vehicles may need to be transported and operated at the job site to complete the job. This can greatly increase the cost of the job and needlessly tie up expensive equipment. If the work vehicle will be used for multiple purposes, various specialty buckets will need to be transported to the job site to complete the job. The task of changing buckets, however, can lead to inefficiency and also increase the risk of job related injuries. This choice and the problems associated with each of the two options could be eliminated by providing a multi-purpose bucket suitable for performing multiple tasks such as excavating; grading; lifting; digging; dislodging rock, stumps and other debris; scooping and lifting; working with hard materials such as rock strata, caliche, soapstone and clay; ripping and trenching; and scraping and leveling. While other have developed multi-purpose attachments for work vehicles (see U.S. Pat. No. 6,820,357 to Menard et al and U.S. Pat. No. 5,564,885 to Staben, Jr.), these attachments have been limited in terms of the number of applications they can perform effectively and efficiently. 
     SUMMARY OF THE INVENTION 
     The present invention relates to work vehicle attachments adept at performing a variety of work related functions. These functions can all be performed by an open bucket having a suitable configuration comprising an open front, a bottom wall, a top wall, a back wall and a pair of side walls. The bottom wall of the bucket has a back edge, a front edge shorter than the back edge, and a pair of side edges. Each of the side edges have a first portion extending from the back edge in a direction normal to the back edge and a second portion extending at an angle from the first portion to an end of the front edge. The top wall of the bucket has a substantially rectangular shape. The front and back edges of the top wall are of substantially the same length as the back edge of the bottom wall. The side edges of the top wall are substantially shorter than the side edges of the bottom wall. A back wall and two side walls join the top wall and the bottom wall. The back wall extends between the back edges of the top wall and bottom wall. Each of the side walls have a top edge substantially co-extensive and joined to a side edge of the top wall, a back edge substantially co-extensive with and joined to a side edge of the back wall, and a bottom edge substantially co-extensive with and joined to the first portion of a side edge of the bottom wall. The front edge of each of the side walls has a first section extending substantially normal to the top wall. This first section extends from the top wall to a point more than two-thirds the distance from the top wall to the bottom wall. The front edge of each side wall also includes a second section extending substantially normal to the bottom wall from the bottom wall. A third section of the front edge of the side wall joints the first and second sections. 
     The attachment also includes a plurality of tines. The tines are joined to the bottom wall and each extends past and over portion of the front edge of the bottom wall. Each tine is spaced from the first portions of the side edges and the center of the front edge of the bottom wall. 
     In some embodiments of the invention, the attachment is joined to a pair of loader arms of a work vehicle. The loader arms each have a longitudinal axis and the tines are positioned so each tine resides between the longitudinal axes of the loader arms. 
     In some embodiments there is an even number of tines. In such embodiments, half the tines reside between the center of the bottom wall and one of the side walls and the other half of the tines reside between the center of the bottom wall and the other of the side walls. Likewise, in some embodiments the tines extend above the bottom wall. Some embodiments also include a length of angle iron along the back edge of the bottom wall. 
     The attachment can also include a thumb. Such a thumb comprises a movable member joined by a hinge connector to one of the walls of the bucket so the movable member is movable between a first position in which the movable member extends across the open front of the bucket and a second, retracted position. A ram such as a hydraulic or pneumatic ram can be used to pivot the movable member about the hinge connector between the first and second positions. 
     In some embodiments, the movable member of the thumb comprises first second and third arm segments. The second arm is connected at one of its ends by a hinge connector to an end of the first arm and at the other of its ends by a hinge connector to an end of the third arm. Hinge connectors are also provided to attach a midpoint of the first arm to a wall of the bucket and to attach the first arm to a ram. The hinge connectors joining the three arms permit the movable member of the thumb to be folded and unfolded with respect to each other. Locking pins may be used to secure the arms in the folded or unfolded positions. 
     The invention briefly described above is suitable for a number of tasks. The attachment is adept at digging and transplanting small trees and shrubs. The shape allows for carrying long objects. The construction allows for a smooth back dragging function. The arrangement of the tines allows them to be used for scarifying, captivating, prying, lifting, separating, moving and positioning of items. The arrangement of the tines also permits the apparatus to be used for setting poles (such as telephone poles) in holes. The arrangement of the tines and the bottom wall of the attachment also impedes movement and rolling of items (such as rocks) within the bucket as such items are being transported. The positioning of the tines also limits certain damaging forces that would otherwise be encountered by the loader arms. 
     These and other advantages of the present invention will be better appreciated from a reading of the detailed description of the invention in conjunction with the drawings provided as part of this specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a first embodiment of the attachment of the present invention attached to the loader arms of a work vehicle; 
         FIG. 2  is another perspective view showing generally the front of the embodiment of  FIG. 1 ; 
         FIG. 3  is still another perspective view showing generally the back of the embodiment of  FIG. 1 ; 
         FIG. 4  is another perspective view showing generally the bottom of the embodiment of  FIG. 1 ; 
         FIG. 5  is a front view of the attachment of  FIG. 1 ; 
         FIG. 6  is a side view of the attachment of  FIG. 1 ; 
         FIG. 7  is a top view of the attachment of  FIG. 1 ; 
         FIG. 8  is a perspective view of another embodiment of the attachment of the present invention; 
         FIG. 9  is another perspective view of the embodiment of  FIG. 8 ; 
         FIG. 10  is another perspective view of the attachment of  FIG. 8  showing the thumb in a folded position for storage. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a pair of loader arms  2 ,  3  of a work vehicle (not shown). Associated with each loader arm is a hydraulic ram  4 ,  5 .  FIG. 1  also shows an attachment  10  secured to each of the loader arms  2 ,  3 . More specifically, a pivot pin  6  is used to pivotally secure the distal end of each of the loader arms  2 ,  3  to the attachment  10 . A pivot pin  7  is likewise used to pivotally secure the distal end of hydraulic rams  4 ,  5  to the attachment  10 . This arrangement permits the attachment  10  to be not only raised and lowered by the loader arms  2 ,  3 , but also be tilted with respect to the loader arms in a conventional fashion. Those skilled in the art should recognize the attachment  10  may be attached to a loader arm is any conventional manner without deviating from the invention. For this reason and to assist in better illustrating the invention, the loader arms  2 ,  3  and rams  4 ,  5  are not shown in the drawings other than in  FIG. 1 . 
     As will be explained with reference to  FIGS. 2-7 , the attachment  10  includes a bucket  12  having a unique shape and construction. Generally, the bucket  12  includes an open front  14 , a bottom wall  16 , a top wall  18 , a back wall  20  and first and second side walls  22  and  24 . 
     The shape of bottom wall  16  is best shown in  FIG. 4 . The bottom wall  16  is essentially a plate having a back edge  30 , a front edge  32 , and side edges  34  and  36 . Each side edge has a first portion  38  and a second portion  40 . As shown, the front edge  32  is generally parallel to the back edge  30 . The front edge  32 , however, is substantially shorter than the back edge. For example, the back edge  30  could be four feet long and the front edge  32  could be three feet long. Typically, the front edge  32  will be about the same length or shorter than the distance between the loader arms  2 ,  3  of the work vehicle. The back edge  30  can either be secured to or comprise an L-shaped piece of angle iron  42 . 
     The first portion  38  of each of the side edges  34 ,  36  extends in a substantially normal direction (i.e., substantially at a 90° angle) from an end of the back edge  30 . The second portion  40  of each side edge  34 ,  36  connects the first portion  38  with the front edge  32 . The angle  44  between the front edge and the second portion  40  of each side edge  34 ,  36  can vary. As shown, this angle is about 135°. This angle ideally (but not necessarily) is between 130° and 140°. 
     As shown in the drawings, the attachment also includes six tines  50 . Each of the tines  50  is fastened to the top of the bottom wall  16 , for example by welds. Each of the tines  50  extend from the back edge  30  of the bottom wall  16  past the front edge  32  of the bottom wall  16 . The tines  50  each extend in a direction normal to, past and over a portion of the front edge  32  of the bottom wall  16 . Further, the tines  50  are all located between the longitudinal axes of the loader arms  2 ,  3 . Each of the tines  50  is spaced from the first portion  38  of the side edges  34 ,  36  of the bottom wall  16 . Each of the tines  50  is also spaced from an imaginary line  51  parallel to the first portions  38  running through the center of the bottom wall  16 . When an even number of tines are used, they are uniformly spaced and no tine resides along this imaginary center line. Each of the tines  50  extends well past the front edge  32  of the bottom wall  16  and terminates at an angled tip  52 . 
     The top wall  18  of the bucket  12  has a substantially rectangular shape having a front edge  54  and a back edge  56  and a pair of side edges  58 ,  60 . The front and back edges  54 ,  56  of the top wall  18  are approximately the same length as the back edge  30  of the bottom wall  16 . The side edges  58 ,  60  of the top wall  16  are substantially shorter in length than the first portions  38  of the side edges  34 ,  36  of the bottom wall  16 . As shown in the drawings, the side edges of the top wall  16  are about one-third the length to the first portion  38  of the side edges  34 ,  36  of the bottom wall  16 . This can vary, but generally the side edges  58 ,  60  of the top wall  18  should be between one-quarter and one-half the length of the first portion  38  of the side edges  34 ,  36  of the bottom wall  16 . 
     The back wall  20  extends between the bottom wall  16  and the back edge  56  of the top wall  18 . The back wall  20  has a center section  62 . As shown in the drawings, center section  62  is substantially shorter in length than the distance between the top wall  18  and bottom wall  16 . The center section  62  also extends along a plane substantially normal to the planes of the top wall  18  and bottom wall  16 . The back wall  20  also has a top section  64  extending between the center section  62  and the back edge  56  of the top wall  18 . A bottom section  66  of the back wall  120  extends between the center section  62  and the bottom wall  16 . The top section  64  and bottom section  66  can either be curved or angled with respect to the center section  62  to provide a bucket shape. 
     The side walls  22 ,  24  each have a top edge  67  substantially co-extensive with and joined to a side edge  58  or  60  of the top wall  18 . The side walls  22 ,  24  also have a back edge  68  substantially co-extensive with and joined to a side edge of the back wall  20 . The bottom edge  70  of each of side walls  58  and  60  is co-extensive with and joined to the first portion  38  of a side edge  34  of  36  of the bottom wall  16 . The front edge  72  of each of side walls  22 ,  24  has a first section  74  extending down from the corner at which the front edge  54  and one of the side edges of the top wall intersect. The first section  74  of front edge  72  extends along a line substantially normal to the top wall  18  to a point  75 . Point  75  is generally along a line parallel to the top wall and extending through the intersection between the center section  62  and bottom section  66  of the back wall  20 . As shown in the drawings, the first section  74  extends more than three-fourths of the length between the top wall  18  and bottom wall  16 , but this is not necessarily the case. 
     The front edge  72  of each side wall  22 ,  24  also has a second section  76 . Section  76  extends upwardly from the intersection of the first portion  38  and second portion  40  of a side edge  34  or  36  of the bottom wall  16  in a direction substantially normal to the bottom wall  16 . 
     Completing the front edge  72  of each side wall  22 ,  24  is a third section  78  extending between the bottom of the first section  74  and the top of the second section  76 . While the angles between the third section and the first and second sections could be a right angle, as shown in the drawings, they are not. The lengths of first section  74  and second section  76  are such that the third section  78  is not at a right angle with respect to the first section  74  or the second section. Instead, the third section  78  slopes toward the bottom wall  16  as it extends away from the first section  74  toward the second section  76 . 
     The construction of the bucket  12  and tines  50  described above offers numerous advantages. The tines can be used to loosen soil and the bucket used to remove the soil when trenching. The tine and bucket arrangement also makes the attachment  10  well suited when transplanting small trees and shrubs. The shape defined by the side walls  22 ,  24  and tines  50  make the attachment well suited for carrying long objects such as tree trunks, poles and lumber. The incorporation of an angle iron at the back edge of the bottom wall is highly beneficial when smoothing excavated ground. The spacing of the tines  50  allow the attachment  10  to be used effectively when scarifying, captivating, prying, lifting separating, moving or positioning items. The spacing of tines  50  also allows the attachment  10  to be used effectively for setting and orienting poles, posts, small trees or the like in holes. When carrying rocks or other objects the arrangement of the tines and walls of the bucket inhibits rolling of such items leading to greater stability and safety. 
     Safety and stability of objects carried by the attachment  10  can be even further enhanced if the thumb assembly  100  shown in  FIGS. 8-10  is also provided as part of the attachment. The thumb  100  has a first position in which it crosses the open front  14  of the bucket  12  as shown in  FIG. 9 . The thumb  100  also has a second, retracted position above the open front  14 . A third folded position is shown in  FIG. 10 . 
     The thumb  100  comprises a movable member  102  having a first arm  104 , a second arm  106  and a third arm  108 . One end of arm  106  is coupled by a hinge connector  110  to an end of the arm  104 . The other end of arm  106  is coupled by a hinge connector  112  to arm  108 . Further, the first arm  104  is connected at a midpoint by a hinge connector  114  to a wall of the bucket  12 . The first arm  104  is also connected to a ram  120  used to pivot the movable member  102  between the first position across the open front  14  of the bucket  12  and the second, retracted position. The thumb  100  also includes one or more locking pins  122  used to lock the position of the arms  104 ,  105  and  108  either in the unfolded position shown in  FIGS. 8 and 9  or the folded position shown in  FIG. 10 . 
     As best shown in  FIGS. 8 and 9 , the arms  104  and  106  each comprise a pair of parallel members  105  and  105   a  secured together by cross members. For example, one or more cross members join the parallel members of arm  104 . One cross member  150  is located at the point where arm  104  is pivotally attached to the ram  120 . Another cross member  152  can be used to pivotally attach arm  104  to hinge connector  114 . A third cross member may be provided where the arm  104  is pivotally attached to arm  106  and serve as hinge connector  110 . The parallel members  107  and  107   a  of arm  106  may be secured together by a cross member (such as  156 ) at hinge connectors  110  and  112 . 
     As also shown in  FIGS. 8 and 9 , the arm  108  comprises four parallel members. These are joined by the cross member  156  at the location of hinge connector  112  and by a second cross member  158  at approximately the midpoint between the hinge connector  112  and the free end  160  of arm  108 . 
     To lock arms  104 ,  106  and  108  in the unfolded position shown in  FIGS. 8 and 9 , a set of locking pins  122  which mate with alignable holes in two of the arms are provided. As shown in  FIGS. 8 and 9 , these pins  122  lock the position of arm  104  relative to arm  106 , and arm  106  relative to arm  108 . When these pins  122  are retracted (or removed), the arms  104 ,  106  and  108  can easily be folded into the position shown in  FIG. 10 . 
     The foregoing description is not intended to be limiting, but rather to explain attributes of the invention and how they can be implemented. The invention is only limited by the claims recited below.

Summary:
A multi-purpose attachment for work vehicles comprises a unique bucket shape and tine arrangement permitting the attachment to be used when performing a variety of jobs at a job site. The attachment may also include a thumb that can be extended over the open front of the bucket, retracted and even folded when not in use.