Abstract:
A wheel rake including an adjustment mechanism for adjusting wheel beam angle for more aggressive or less aggressive raking action.

Description:
RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Application No. 60/503,423 filed Sep. 16, 2003, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to towable agricultural implements and more particularly to wheel rakes useful to form windrows from cut forage.  
       BACKGROUND OF THE INVENTION  
       [0003]     A primary goal in the harvesting of hay or forage is to dry the hay as soon as possible and then to remove it from direct exposure to sunlight. The hay must be dried before storage to avoid the problems of mold and spontaneous combustion. Exposing the cut hay to sunlight longer than is required to adequately dry it, however, can result in unacceptable loss of nutritive value of the hay due to deterioration of the protein level.  
         [0004]     Typically, hay is harvested into approximately five-foot swaths along the ground, and is exposed to sunlight for the initial stage of the drying process. These swaths spread out the hay to maximize exposure to the sun and air to speed initial drying. The swaths of hay are then raked into narrow windrows to remove most of the hay from direct contact with the moist ground. The windrow enhances air circulation within the hay, thereby hastening the drying process. Raking hay into windrows also facilitates gathering of hay by providing rows of forage for a hay baler or other harvesting device to follow.  
         [0005]     Many types of wheel rakes have existed for decades. Wheel rakes utilize angled, tined “pinwheels” that are propelled across the ground of a field of cut forage. Contact with the ground while traveling across the ground rotates the wheels and thereby rakes the hay in a desired direction. Of particular interest are V-rakes in which at least two banks of rake wheels are deployed in the shape of a V during operation. Generally, V-rakes employ an arm on each side of a frame to support the wheel rakes. Such V-rakes are used to rake forage into a windrow by raking the forage from the outer edges of the implement inward. V-rakes are preferably adjustable so that the width of the windrow produced is variable and the swath raked on each pass is optimal for the circumstances encountered. For optimal operation, it is preferable that the relative angle of the wheel banks and the width of their separation be independently adjustable.  
         [0006]     Wheel rakes are subject to repeated structural stresses due to uneven ground and irregular distribution of forage material when propelled through fields of cut hay to form the hay into windrows. The assemblies supporting the rake wheels must have considerable strength in order to bear such stresses successfully. Welded assemblies are thus preferred for their robustness and durability.  
         [0007]     Wheel rakes convert the forward motion of the rake into a lifting and sideward motion by interaction of the rake wheels with the ground as the wheel rake is drawn forward. Compacted, damp or unusually heavy forage can create problems in that the rake wheels may tend to roll over or skip over areas of heavy compacted forage rather than lifting it and raking it toward the desired windrow. If this occurs, loss of production and increased costs result. Loss of production occurs if forage is left in the fields to decay rather than being harvested. Increased costs can occur if it is necessary to pass through the fields several times to accomplish sufficient raking to gather all of the forage desired. Thus, the efficiency of a wheel rake for lifting and moving forage can have a significant economic effect on hay farming.  
         [0008]     Rake wheels include a plurality of tines extending from the rim of the wheel. Flexible metal tines lift and move forage to one side as the rake wheels rotate.  
         [0009]     Traditionally, and sometimes today, tines extend the entire distance from the rake wheel hub beyond the rim. More commonly tines are attached to the wheel rim and the rim to the hub via spokes or a wheel disk. In the event that spokes are utilized, the spokes are often covered by a plastic disc. This arrangement keeps forage from passing through the wheel instead of being raked as desired.  
         [0010]     Modern rake wheels often utilize metal tines mounted in flexible rubber bases. The rubber bases secure the tines to the wheel rim and provide a measure of controlled flexibility so that the tine can flex in response to loads in all directions without bending or breaking.  
         [0011]     Wheel rakes are typically constructed so that multiple rake wheels are mounted side by side mounted on long beams. It is desirable that the beams be adjustable in width or separation and in the angle that the beams make with the path of travel as viewed from above. Prior wheel rakes have not allowed any adjustment of vertical raking angle.  
         [0012]     The angle at which rake wheels contact the ground during the raking operation affects the ability of the wheel tines to lift and move forage. A more aggressive raking angle is one where the plane of the rake wheels is angled somewhat from the vertical. A less aggressive raking angle keeps the plane of the rake wheels close to vertical relative to the ground. At some times, when forage is heavy or compacted a more aggressive raking angle is desirable. At other times, conditions are such that forage left in the fields is light and not compacted. At these times, it would be valuable to be able to harvest forage with a less aggressive raking angle to minimize wear on wheel rake components.  
         [0013]     A more aggressive raking angle allows the tines or fingers of the rake wheels to “dig in” better. That is, the tines reach under the forage to a greater degree. This greater reaching under tends to provide better lift and application of sideward force to the forage to improve the raking of heavy or compacted forage.  
         [0014]     Thus, it would be a benefit to the agricultural arts to have access to a hay rake that allows for adjustment of raking angle to allow for ready adjustment from a less aggressive raking angle to a more aggressive raking angle.  
       SUMMARY OF THE INVENTION  
       [0015]     The wheel rake of the present invention solves many of the above problems by providing a robust and easily adjustable mechanism that allows for the adjustment of the raking angle of the wheel rake. The present invention allows the operator to adjust raking angle relative to the ground easily with basic tools. The invention allows an operator to adjust the raking angle to be more aggressive when it is necessary to provide for the raking of heavy or compacted forage. Likewise, the invention allows an operator to return the raking angle to a less aggressive setting easily and quickly. The angle adjustment of the present invention is robust and sturdy to stand up to the high stresses inherent in the use of wheel rakes over the uneven ground in cultivated fields.  
         [0016]     The wheel rake of the present invention generally includes a carriage and two rake assemblies. The rake assemblies are generally mirror images of one another and each include a beam supporting a plurality of rake wheels. The beams are adjustable in many ways. The beams are adjustable to provide different raking angles relative to the path of travel of the wheel rake as viewed from above. The beams are supported near their centers on a vertical shaft that allows for angling the beams about a vertical axis to change the angle relative to the forward motion of the wheel rake.  
         [0017]     The beams are supported by a central carriage that can be adjusted to change the separation between the rake assemblies by telescopically widening or narrowing the carriage.  
         [0018]     The beams are adjustable about a horizontal axis generally parallel to the long axis of the beam to adjust the aggressiveness of the raking angle. The beams are hingedly attached to the vertical shaft so that the raking angle can be easily changed. In one embodiment of the invention a first plate is attached to the beam and a second plate is attached to the vertical shaft. The two plates are both joined to a hinge barrel. Adjustment is accomplished with basic tools by moving an adjustment bolt to force the two plates apart to angle the beam and thus the rake wheels as desired.  
         [0019]     The adjustment bolt is threaded into a threaded sleeve that is secured to one of the plates so that the adjustment bolt bears on the other plate. When the adjustment bolt is turned inward it bears against the other plate and forces the plates apart. Since both the plates are joined to the hinge barrel, forcing the plates apart also angles them relative to one another. The first plate carries the beam along with it, thus angling the beam relative to the carriage and the ground. The raking wheels are carried along with the beam and angled relative to the ground to increase the aggressiveness of the raking angle.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective view of a wheel rake in accordance with the present invention with the raking angle adjusted to a less aggressive setting;  
         [0021]      FIG. 2  is a detailed perspective view of an adjuster in accordance with the present invention taken from area A in  FIG. 1 ;  
         [0022]      FIG. 3  is a perspective view of the wheel rake with the wheel angle set for more aggressive raking;  
         [0023]      FIG. 4  is a detailed perspective view of the adjuster as taken from area B of  FIG. 3 ;  
         [0024]      FIG. 5  is a perspective view of a hinge adjuster and support column in accordance with the present invention;  
         [0025]      FIG. 6  is a front plan view of the hinge adjuster in accordance with the present invention;  
         [0026]      FIG. 7  is a rear perspective view of a hinge adjuster in accordance with the present invention;  
         [0027]      FIG. 8  is a perspective view of the wheel rake folded to a transport configuration; and  
         [0028]      FIG. 9  is a perspective view of the wheel rake with certain parts removed for clarity.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]     Referring particularly to  FIGS. 1, 3  and  8 , wheel rake  30  generally includes carriage  32  and two rake assemblies  34 . Rake assemblies  34  are generally mirror images of one another and are supported by carriage  32 . Wheel rake  30  may also include one rake assembly  34  or more than two rake assemblies  34 .  
         [0030]     Carriage  32  generally includes cross frame  36 , columns  38 , wheels  40  and drawbar  42 . Cross frame  36  generally includes central bridge  44  and sliders  46 . Central bridge  44  is a robust structure desirably constructed of four parallel square tubes  48 . Two square tubes  48  are stacked one on top of another in a front assembly  50  and two more square tubes are stacked one on top of the other in a rear assembly  52 . Front assembly  50  and rear assembly  52  are interconnected and joined by cross braces  54 . Sliders  46  telescopically slide within central bridge  44 . Sliders  46  are desirably constructed of square tubes  56  that are sized to slidably fit within box channel  48 . Each slider  46  terminates at a plate  58  at an outward end thereof. Sliders  46  are desirably operably connected to hydraulic rams (not shown).  
         [0031]     Columns  38  are secured to the ends of sliders  46  at plate  58 . Columns  38  support carriage  32  and are supported by wheels  40  at a bottom end thereof. Wheels  40  may be staggered as depicted in  FIGS. 1 and 3 . Wheels  40  can include more or less wheels than depicted here. Note that wheels  40  are closely spaced and support the entirety of wheel rake  30  reducing the likelihood of damage to rake assemblies  34  that arises when rake assemblies  34  are supported by wheels  40  at their ends and the end located wheels are caught by obstructions in the field.  
         [0032]     Draw bar  42  is secured to central bridge  44 , desirably, by pins. Draw bar  42  terminates at a front end thereof at hitch  60 . Hitch  60  is adapted to be connected to a prime mover (not shown). The prime mover can include a tractor or a pickup truck. Thus, hitch  60  may be interchangeable to accommodate connection to a ball hitch, a pintle hook or other type of hitch. Hitch  60  may include an adjustment mechanism to adjust the height of the hitch  60  to accommodate differing hitch heights of varying prime movers.  
         [0033]     Rake assembly  34  generally includes beam  62 , rake wheels  64  and beam support  66 . Beam  62  supports a plurality of rake wheels  64 . Rake wheels  64  are each connected to beam by a trailing link  68 . Trailing link  68  is pivotably connected to beam  62  to one end and to rake wheel  64  at the other. Rake wheels  64  are free to rotate at the end of trailing link  68  and further free to travel up and down along a limited arc of motion to follow ground contour. Trailing link  68  may be biased toward the ground so as to provide a resistive force to the tendency of rake wheels  64  to be pushed upward by irregularities in the terrain over which wheel rake  30  operates. Beam  62  is operably connected to column  38  by beam support  66 .  
         [0034]     Beam support  66  includes hinged angle adjuster  70  and clamp  72 . Clamp  72  secures hinged angle adjuster  70  to beam  62 . Clamp  72  may be a U-bolt or other clamping assembly. Additionally, beam  62  may be secured to beam support  66  in any way known to those skilled in the art.  
         [0035]     Hinged angle adjuster  70  is also secured to column  38  via vertical shaft  74 . Vertical shaft  74  is operably connected to column  38  so as to be pivotal about a vertical axis. Hinged angle adjuster  70  may be welded to vertical shaft  74  or attached by other suitable means.  
         [0036]     Referring particularly to  FIGS. 2 and 4 - 7 , hinged angle adjuster  70  generally includes beam plate  76 , vertical shaft plate  78  and hinge barrel  80 . Beam plate  76  is secured to beam  62  preferably by U-bolts  82 . Vertical shaft plate  78  is secured to vertical shaft  74 , preferably by welding.  
         [0037]     Referring to  FIGS. 4, 6  and  7 , vertical shaft plate  78  supports adjuster  84 . Adjuster  84  includes adjustment bolt  86 , locking bolt  88  and locking nut  90 . Adjuster  84  may also be structured another way to achieve the same angular adjustment qualities.  
         [0038]     Referring to particularly to  FIGS. 2, 4 ,  6  and  7 , adjustment bolt  86  is supported in threaded collar  92 . Threaded collar  92  is secured or integrally formed into vertical shaft plate  78 . Locking bolt  88  passes through beam plate  76  and vertical shaft plate  78  via apertures (not shown). The head of locking bolt  88  may be secured to either vertical shaft plate  78  or beam plate  76 . Thus, end  96  of adjustment bolt  86  bears against beam plate  76  and hex head  98  of adjustment bolt  86  protrudes through threaded collar  92 . Locking bolt  88  passes through beam plate  76  and then through vertical shaft plate  78 . Locking nut  90  bears against vertical shaft plate  78  when tightened. Other methods of constructing adjuster  84  will be apparent to one skilled in the art that would not depart from the spirit of the invention.  
         [0039]     Beam plate  76  and vertical shaft plate  78  are each joined to hinge barrel  80 . Hinge barrel  80  pivots about hinge pin  100 . Hinge pin  100  has a long axis generally parallel to beam  62  and oriented generally horizontal relative to the ground.  
         [0040]     Adjustment bolt  86 , locking bolt  88  and locking nut  90  may be duplicated on vertical shaft plate  78 . For example, one set of adjustment bolt  86 , locking bolt  88  and locking nut  90  may be located on each side of vertical shaft  74 .  
         [0041]     In operation, raking angle may readily be adjusted. Referring to  FIGS. 1-2 , beam  62  is depicted in a straight vertical position. In this position, rake wheels  64  are less aggressively angled relative to the ground and appropriately positioned for raking normal forage from the ground.  
         [0042]     Referring particularly to  FIG. 2 , with beam  62  in the straight position, adjustment bolts  86  is backed out of threaded collar  92  allowing beam plate  76  to lie flush against vertical shaft plate  78 . Locking bolt  88  is pulled against beam plate  76  by tightening of locking nut  90 . Adjustment bolt  86  may then be tightened to prevent its loss by backing out of threaded collar  92 .  
         [0043]      FIGS. 3, 4 , and  6 - 7  depict rake wheels  64  more aggressively angled relative to the ground and appropriately positioned for raking heavy, wet or compacted forage from the ground.  
         [0044]     Referring particularly to  FIGS. 4, 6  and  7 , when it is desired to move beam  62  to a more aggressive raking position, an operator first loosens locking nut  90  in order to create slack in locking bolt  88 . The operator then turns adjustment bolt  86  inward to cause end  96  to bear against beam plate  76  thus rotating beam plate  76  about hinge pin  100  and creating a more aggressive raking angle for beam  62  and rake wheels  64 . Once adjustment bolt  86  is adjusted to the desired point, the operator then may tighten locking nut  90  drawing locking bolt  88  against beam plate  76 , thus drawing beam plate  76  toward vertical shaft plate  78  and locking adjustment bolt  86 , thus securing beam  62  at an aggressive raking angle.  
         [0045]     The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.