Abstract:
A seed bed packer including a frame, a plurality of wheels connected to the frame, and a soil packing element. The packer also includes a spring shank for transferring weight from the frame to the soil packing element. The spring shank includes a first leg connected to the frame and a second leg connected to the soil packing element. When weight is transferred through the spring shank to the packing element, the first and second legs flex toward one another. The spring shanks are capable of distributing the weight of the frame between the wheels and the packing element, while concurrently providing sufficient flexibility to allow the packing element generally uniformly pack the soil, even over rough terrain.

Description:
TECHNICAL FIELD 
     The invention is directed generally to agricultural implements for conditioning soil. More particularly, the present invention relates to implements having packer tools intended to achieve a uniform packing of a bed of soil for subsequent planting or to achieve uniform packing of a bed of soil after it has been planted. 
     BACKGROUND 
     Known seed bed packers have a frame which is typically towed behind a tractor or other implement. The frame is supported by wheels and includes a tool bar to which packer tools are connected. The problem with some seed bed packers is that most of the weight of the frame rests on the wheels with a lesser amount of weight resting on individual packer tools. As a result, the wheels often pack loose soil much more substantially than the packer tools. Hence, when a crop is planted, discontinuities in growth can be apparent due to the soil packing differences. 
     U.S. Pat. No. 5,181,573 (commonly assigned) illustrates a drawbar packer having coil packers  28  connected to a frame  14  by connecting assemblies  30 . The connecting assemblies  30  allow the packers  28  to pivot relative to the frame  14 . Coil springs  48  are provided for biasing the coil packers  28  toward the ground. A concern with the connecting assembly  30  is that it includes movable parts that can require maintenance and are potentially more expensive to manufacture. What is needed is a simple, inexpensive and durable system for transferring weight to the packing elements (e.g., the packer coils) of a seed bed packer to provide optimal soil surface condition and density. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention relates to an agricultural implement including a frame, a plurality of wheels connected to the frame, and a soil conditioning element. The implement also includes a spring shank for transferring weight from the frame to the soil conditioning element. The spring shank includes a first leg connected to the frame and a second leg connected to the soil conditioning element. When weight is transferred through the spring shank to the conditioning element, the first and second legs flex toward one another. The spring shank is capable of distributing the weight of the frame between the wheels and the conditioning element, while concurrently providing sufficient flexibility to allow the conditioning element to generally uniformly condition the soil, even over rough terrain. In one embodiment, the conditioning element is a soil packing element. 
     A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a portion of a seed bed packer in accordance with the present invention; 
     FIG. 2 is a perspective drawing of a coil packer implement and spring shank assembly used by the seed bed packer of FIG. 1; 
     FIG. 3 is a side view of the coil packer implement and spring shank assembly of FIG. 2; 
     FIGS. 4A-D are several orthogonal views of a flexible spring shank used by the spring shank assembly of FIG. 2; and 
     FIG. 5 is an exploded perspective view of portions of the coil packer implement and spring shank assembly of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1, a drawbar seed bed packer in accordance with the present invention is designated generally by the numeral  10 . The seed bed packer  10  is adapted to be towed by a vehicle over soil being prepared for planting or post planting. The seed bed packer  10  includes a frame  12  having a plurality of wheel assemblies  14  connected thereto. A towbar assembly  15  is provided for connecting the frame  12  to the towing vehicle. Coil packer assemblies  16  are connected to the frame  12 . 
     The frame  12  of the seed packer  10  includes a pair of spaced-apart bars  18  and  20  running transverse to the direction of travel of implement  10 . A plurality of members  22  are attached to and extend between bars  18  and  20  to provide a rectangular frame work. FIG. 1 shows approximately one half of the frame  12 . However, it will be appreciated that the entire seed bed packer  10  is preferable symmetrical about a central axis  13 . 
     The towbar assembly  15  of the frame  12  includes a pair of beams  15 ′ which preferably converge near a structure (not shown) adapted for allowing the seed bed packer  10  to be hitched to the towing vehicle. 
     The wheel assemblies  14  of the seed bed packer  10  are attached to frame  12  in a known fashion using a dependent bracket in conjunction with bearings, axles, wheels, and appropriate connecting and other hardware. The wheel assemblies  14  may be connected to any part of frame  12  as appropriate, including bars  18 ,  20  and members  22 , as shown in FIG.  1 . 
     The coil packer assemblies  16  of the seed bed packer  10  include coil packers  24  attached through a flexible spring shank assembly  26  to the frame  12 . Preferably, a pair of shank assemblies  26  are provided for each coil packer  24 . As shown in FIG. 1, some of the coil packers  24  are connected to the toolbar  18 , and others are connected to the tool bar  20 . The coil packers  24  attached to the tool bar  18  trail the wheels of the various wheel assemblies as shown. The coil packers  24  attached to the bar  20  are positioned between the wheel assemblies and between the coil packers trailing the wheel assemblies thereby providing full packing coverage as the implement is pulled. 
     Adjacent a central wheel assembly  31 , the frame  12  includes an offset bracket  33  attached to the bar  18 . One of the coil packers  24  is connected to the offset bracket  33 . The offset bracket  33  provides a greater trailing distance between the central wheel assembly  31  and the coil packer  24 . 
     The frame  12  of the seed bed packer  10  includes a center portion  32 , and wing portions  28  connected to the center portion  32  by hinges  29 . A hydraulic system is provided for pivoting the wing portions  28  relative to center portion  32 . For example, the hydraulic system can include cylinder assemblies  30  which function to pivot the wing portions  28  about the hinges  29  between raised and lowered positions. Typically, the wing portions  28  are moved to the raised position for transport of the seed bed packer  10 , and are moved to the lowered position for soil conditioning operations. Additionally, cylinder assemblies  34  are provided to lift the entire frame  12  relative to the central wheel assemblies  31 . Preferably, the frame  12  is lifted relative to the central wheel assemblies  31  to facilitate transporting the seed bed packer  10 . The present invention is equally applicable to an implement either having or not having wing portions. 
     The flexible spring shank assemblies  26  are shown in more detail in FIGS. 2-5. Each flexible spring shank assembly  26  includes a flexible spring shank  36  and attachment hardware for mounting the spring shank  36  to the frame  12 . The term “spring shank” will be understood to mean a non-coiled member that has elastic or spring-like characteristics. The flexible spring shank  36  includes a top portion which is connected to the frame  12  (e.g., to the bars  18 ,  20  or the offset bracket  33 ) and a lower portion which is connected to the coil packer assemblies  16 . It will be understood that the term “connected to” includes direct connections as well as connections provided by intermediate structures. 
     The attachment hardware includes a top plate  38 , a bottom plate  40  and bolts  42  and  54 . As shown in FIGS. 2 and 3, the bar  18  is clamped between the upper and lower plates  38 ,  40  by the bolts  42 . The upper portion of the shank  36  is clamped between the bottom plate  40  and the underside of the bar  18 . It will be appreciated that the upper portion of the shank  36  can be secured to other portions of the frame  12  (e.g., to the bar  20  or to bracket  33 ) in a similar manner. 
     Still referring to FIGS. 2 and 3, the bottom portion of the flexible spring shank  36  is attached to the coil packer assembly  16  by way of the U-bolts  54 . The U-bolts  54  clamp the bottom portion of the flexible spring shank  36  to a frame  44  which forms a part of the coil packer assembly  16 . Particularly, the shank  36  is connected to a piece of square tube  45  that forms a central extension of the frame  44 . The central extension of the frame  44  has a center location or midpoint  43  and ends. Attached to the ends of the square tubing  45  are L-shaped tubing members  46  and  48 . Legs of the L-shaped tubing members  46  and  48  are inserted within the square tubing  45 . In general, the center  43  of the frame  44  of the coil packer assembly  16  is located between opposing ends defined by the L-shaped tubing members  46  and  48 . The opposing ends are generally at equal distances from center. As best shown in FIG. 5, the L-shaped tubing members  46  and  48  are retained within the square tubing by transverse bolts  62  that extend through openings  63  defined by the legs of the L-shaped members  46 ,  48  and through openings  65  defined by the central square tube  45 . U-bolts  52  and plate  50  are also used to secure the L-shaped members  46  and  48  to the central tubing member  45 . 
     The L-shaped tubing members  46  and  48  are provided to mount bearings that support the ends of an axle  53 . The axle  53  extends parallel to the square tubing piece  45 . As shown in FIG. 2, the axle  53  is connected to its corresponding coil packer  24  by end plates  55 . 
     FIGS. 4A-D illustrate various views of the flexible spring shank  36 . As shown in the Figures, a mounting hole  56  is provided through the top portion of the flexible spring shank for receiving the bolt  42  that clamps the flexible spring shank  36  to the frame  12 . Mounting holes  60  are also provided through the bottom portion of the flexible spring shank  36  for receiving the U-bolt  54  that connects the shank  36  to the frame  44  of the coil assembly  16 . As shown in FIG. 2, the shanks  36  are preferably mounted on either side of the center  43  of the frame  44  at a distance closer to the center than to the ends of the coil assembly  16 . 
     As shown in FIG. 4B, the spring shank  36  is generally U-shaped. In such an embodiment, the “upper portion” comprises a first straight leg  61 , and the “lower portion” comprises a second straight leg  63  that is generally parallel to the first leg  61 . A curved portion  65  interconnects the legs  61 ,  63  and holds the legs in vertically spaced-apart relation with respect to one another. In alternative embodiments, the curved portion  65  could be replaced with one or more straight portions. In one non-limiting embodiment, the shank  36  is made of a length (e.g., a bar or strip) of a resilient material (e.g., spring steel) having a rectangular transverse cross-section. However, it will be appreciated that other cross-sectional shapes could also be used. 
     In use, the seed packer  10  is pulled behind a tractor or other towing vehicle. To prevent the wheels  14  from over packing the soil, the spacing between the legs  61  and  63  is selected such that a significant portion of the weight of the frame  12  is transferred through the shanks  36  to the coil assemblies  16 . Preferably, the weight is distributed such that the coil assemblies  16  provide greater packing than the wheels. As weight/loading is transferred through the shanks  36 , the legs  61 ,  63  of the shanks  36  are caused to flex toward one another (i.e., the shanks  36  are compressed such that the spacing between the legs  61 ,  63  is less than when the shanks are in an at rest, non-compressed state). The configuration of the spring shanks  36  also allows the coil packers  16  to move up and down in response to variations in soil contour. Specifically, the legs  61 , 63  of the shanks  36  flex toward and away from one another in response to variations in soil contour thereby allowing vertical movement of the coil packers  16 . This flexibility provided by the flexible spring shanks  36  allows the packer coils  16  to apply relatively constant packing loads to the ground even in uneven terrain. 
     Thus, the embodiment of the apparatus in accordance with the present invention has been described in detail. In this regard, it is understood, however, that the disclosure is exemplary and that equivalents are possible. For example, while coil packers are the preferred packing elements, other packing elements such as press wheels or other similar structures could also be used. Also, other soil conditioners such as rolling baskets could be used instead of packing elements to achieve different types of soil conditioning. Therefore, it is further understood that changes made, especially in matters of shape, size and arrangement to the full extent extended by the general meaning of the terms in which the appended claims are expressed, are within the principle of the invention.