BACKGROUND OF THE INVENTION 
       [0001]    Various sod placement machines are known. U.S. Pat. Nos. 5,697,452; 4,777,890; 6,131,668 and 6,213,218 describe machines which are utilized to roll out sod from a roll to be oriented as a flat strip on the ground. While efforts are made to roll adjacent strips with minimal gaps or seams between adjacent strips, this is not always easily accomplished. Frequently, additional measures must be taken to laterally push a sod strip toward and against an adjacent strip to close a gap or seam between strips. This is sometimes done by manual labor or by using the traction force of a bucket loader or like vehicle. 
         [0002]    The present inventor has recognized that using traction force from a vehicle to push sod strips can be undesirable because of the detrimental effect of the vehicle tires have on the un-sodded bare ground that supports the tires of the vehicle. The traction between tire and ground required for the vehicle to push the sod strip can cause ruts under the tires of the vehicle in the sand bed that awaits subsequently laid sod strips. This causes additional preparation work. Additionally, since the vehicle must be driven perpendicularly to the longitudinal strip direction, the vehicle must be constantly reoriented from strip to strip which also can cause ruts and unevenness in the sand or earth bed that awaits subsequently laid sod strips. 
         [0003]    The present inventor has recognized that it would be desirable to provide a machine that accomplished the task of laterally positioning sod strips, already laid out flat on the ground, to tightly pack adjacent strips to minimize or eliminate gaps in the seams of adjacent sod strips. 
       SUMMARY OF THE INVENTION 
       [0004]    The exemplary device of the invention provides an attachment or enhancement to a sod placement machine or other vehicle that comprises a pushing apparatus for pushing a sod strip that is already placed on the ground, tightly against an adjacent sod strip that is already placed on the ground. This action tightens up the seams between sod strips. The enhancement includes a stationary frame carried by the vehicle and a laterally sliding frame carried by the stationary frame. A pair of hydraulic or pneumatic cylinders are arranged to pivot the frames up or down between a deployed position and a stand-by or traveling position. The device includes a pair of hydraulic or pneumatic cylinders that are operable to slide the laterally sliding frame in a direction away from the stationary frame to push a sod strip, or toward the stationary frame to retract the laterally sliding frame closer to the vehicle for transport to a subsequent sod strip to be pushed. The laterally sliding frame includes a pair of sliding box beams that telescopically retract into box beams of the stationary frame. The sliding beams mount a pushing plate that abuts the sod strip during a pushing operation. 
         [0005]    The sod positioning apparatus pushes the sod strips laid end-to-end to have a common straight line longitudinal edge. This increases the efficiency of the sod laying process. Also, by laterally pressing the sod strip using the apparatus of the invention, the sod strip is compressed and the density of sod increases. For example, a 42 inch wide sod strip can be compressed to 40 inches wide during positioning. 
         [0006]    An alternate pushing plate comprises spikes extending from a bottom of the plate for use is pushing sod strips that are surrounded by sod or other obstacles that prevents exposing a side edge of the sod strip. The plate can be placed over the sod and penetration of the spikes into the sod strip creates a gripping that can be used to laterally shift the sod using the apparatus of the present invention. 
         [0007]    Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, and from the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic plan view of a prior art method of laterally shifting sod steps; 
           [0009]      FIG. 2  is a perspective view of a sod positioning apparatus of the present invention; 
           [0010]      FIG. 3  is an enlarged perspective view of part of the apparatus shown in  FIG. 2 ; 
           [0011]      FIG. 4  is another perspective view of the apparatus shown in  FIG. 2 ; and 
           [0012]      FIG. 5  is a bottom perspective view of an alternate plate used on the apparatus shown in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
         [0014]      FIG. 1  illustrates a few strips  20  of sod that have been laid in a longitudinal direction L of the sod strips onto a bed  26  of sand or the like. A most recently laid strip  20   a  is shown being pushed in the lateral direction P by a vehicle  30 , such as a “skid steer” loader or the like in order to tighten up the packing of the adjacent strips, i.e., to close or minimize the seam or gap  31 . The vehicle  30  is driven by wheels and tires  36  that achieve forward traction force in the direction P by the interaction between the tires  36  and the bed  26 . This interaction can cause ruts or other irregularities in the bed which must be smoothed before a subsequent strip  20   b  (shown dashed) is placed on the bed  26 . 
         [0015]    A future strip to be laid is shown dashed as  20   c . In order for the vehicle  30  to be positioned against the strip  20   c  to push in the lateral direction P, in practical terms, the vehicle must turned, driven and reoriented. This also can cause ruts or other irregularities in the bed which must be smoothed before a subsequent strip  20   b  (shown dashed) is placed on the bed  26 . 
         [0016]      FIGS. 2-4  illustrate an apparatus  50  that overcomes the drawbacks of the prior method. The apparatus  50  includes an attachment or enhancement sod positioning apparatus  60  that is mounted on a vehicle  66 . The vehicle  66  can be a sod placement vehicle such as described in U.S. Pat. No. 6,213,218, herein incorporated by reference. The vehicle  66  comprises a chassis frame  68  that is supported on six traction wheels and tires  70 , at least one of which is driven by an engine and drivetrain (not shown). The vehicle can also provide a source (not shown) of controllable hydraulic or pneumatic pressurized working fluid to operate the apparatus  60 , such as a compressor or pump and associated controls. The frame  68  includes a bay  74  in which a spindle  75  is mounted on a fork frame  76  that is used to hold and unroll sod rolls during placement of the sod strips onto the bed  26 . The fork frame  76  is controlled to pivot up or down depending on the degree of depletion of sod on a sod roll. To this end a hydraulic cylinder  67   a  is connected between a stationary post  67   b  on the chassis frame  68  and a cross beam  76   a  of the frame  76 . The frame is pivotal about an axis defined by two aligned pivot connections  76   c  (only one visible in  FIG. 4 ). Thus retraction of the cylinder  67   a  will draw the cross member  76   a  back and pivot the frame  76  up at the end supporting the spindle  75 , by pivoting the frame about the pivot connections  76   c . Expansion of the cylinder will lower the spindle end of the frame  76 . Sod installation machine frame can be expanded to accommodate sod rolls of different widths, such as 30 inches, 42 inches, 48 inches and 52 inches. 
         [0017]    The vehicle can be driven by a plurality of hydraulic motors, such as one per each wheel, or other known traction drive. The vehicle can include a hydraulic oil system that drives the traction motors, controls steering, and raises and lowers the fork frame and spindle that holds a sod roll, all controlled at an operators station  77 . 
         [0018]    Also mounted on the chassis frame  68  is a hydraulic oil pump  79  and a fuel tank  81  ( FIG. 4 ). 
         [0019]    The apparatus  60  comprises two posts  78 ,  80  that are fixedly mounted to the frame  68  at a rear and front respectively of the near side of the vehicle, such as by fasteners or welding. A substantially U-shaped base frame  90  comprises rear and front base tubes  94 ,  96  respectively. The base tubes  94 ,  96  can have a square cross section and are hollow. A longitudinal brace tube  100  connects the rear and front tubes  78 ,  80 . The rear and front base tubes  94 ,  96  have open ends  94   a ,  96   a , respectively. The front tube  96  is connected at a low position to the post  80  by a pin connection  106  to a pair of lugs  80   a  to allow pivoting of the tube  96  with respect to the post  80 . The rear tube  94  is connected at a low position to the post  78  by a pin connection (not visible in  FIG. 2 ) to allow pivoting of the tube  94  with respect to the post  78 , in an identical fashion as the front tube  96  is pivotally connected to the front post  80 . 
         [0020]    The frame  90  is supported from the posts  78 ,  80  by a pair of actuators, such as hydraulic or pneumatic cylinders, a rear cylinder  110  and a front cylinder  112 . The rear cylinder is pivotally connected to an upper position on the post  78  by a pin connection  110   a  to a lug  78   a . The cylinder  110  is also connected to a lug  94   b  on the tube  94  by a pin connection  110   b . The front cylinder is pivotally connected to an upper position on the post  80  by a pin connection  112   a  to a lug  80   b . The cylinder  112  is also connected to a lug  96   b  on the tube  96  by a pin connection  112   b.    
         [0021]    By hydraulic or pneumatic pressure control of the working fluid into select ports of the cylinders  110 ,  112 , the cylinders can be made to work in unison to contract or elongate which will either pivot the frame  90  up or pivot the frame  90  down with respect to the posts  78 ,  80 . In the case of using hydraulic cylinders, the flow of pressurized fluid to the cylinders is maintained uniform through pressure regulating valves, enhancing performance. 
         [0022]    A pushing frame  150  is carried by the base frame  90 . The pushing frame  150  comprises rear and front arm tubes  156 ,  158 . The arm tubes  156 ,  158  are shaped and sized to slidably and telescopically fit into the open ends  94   a ,  96   a  of the base tubes  94 ,  96  and to slide into the base tubes  94 ,  96 , respectively. A front of each of the arm tubes  156 ,  158  is connected to a pusher plate  170  via lugs  172 ,  174  by pin connections  156   a  and  158   a . The plate  170  has a bottom wall  178  and an upturned front wall  180 . 
         [0023]    A rear hydraulic or pneumatic cylinder  202  is mounted between the arm tube  156  and the base tube  94 . A front hydraulic or pneumatic cylinder  206  is mounted between the arm tube  158  and the base tube  96 . Since the rear hydraulic tube is less visible in  FIG. 2 , the mounting of the front cylinder  206  will be described with the understanding that the rear cylinder  202  is mounted in identical fashion to the arm tube  156  and the base tube  94 , as the front cylinder  206  is mounted to the arm tube  158  and the base tube  96 . 
         [0024]    One end of the cylinder  206  is connected by a pin connection  206   a  to the arm tube  158  via a lug  158   b  extending on a bottom side of the arm  158  and an opposite end of the cylinder  206  is connected by a pin connection  206   b  to the base tube  96  via a lug  96   b  extending on a bottom side of the base tube  96 . 
         [0025]    By hydraulic or pneumatic pressure control of the working fluid into select ports of the cylinders  202 ,  206 , the cylinders can be made to work in unison to contract or elongate, which will either slide the tube arms  156 ,  158  in a direction out of the base tubes  94 ,  96  or retract the tube arms  156 ,  158  into the base tubes  94 ,  96 . In the case of using hydraulic cylinders, the flow of pressurized fluid to the cylinders is maintained uniform through pressure regulating valves, enhancing performance. 
         [0026]    Sliding the tube arms  156 ,  158  in a direction out of the base tubes  94 ,  96  pushed the frame  150  away from the vehicle to force the plate  170  to laterally push a sod strip in the direction P by forcing the upturned front wall  180  against a vertical lateral side of the sod strip  20 . Retracting the cylinders  202 ,  206  will retract the frame away from sod strip and ready the frame for pushing against a subsequent strip. Thus, the movement of the pushing plate is in the lateral direction P that is perpendicular to a straight ahead driving direction V of the vehicle, i.e., the direction wherein the wheels are n of turned but directed straight ahead. This allows the vehicle  66  to only travel in the straight ahead driving direction V parallel to the longitudinal direction L to move from strip to strip and still undertake lateral positioning adjustment of the sod strips to tighten up seams between adjacent strips in the direction P. A reorientation of the vehicle on the bed  26  to align a vehicle straight ahead driving direction in the direction P is avoided. 
         [0027]      FIG. 4  also shows a stop assembly  216  comprising a threaded tube or threaded ferrule  217  welded to the bottom wall  178  and a bolt  218  adjustably threaded into the ferrule  217 . The head  218   a  of the bolt  218  abuts the underside of the arm  158  if during positioning of the sod strip by hydraulic pressure from the cylinders  110 ,  112 ,  202 ,  206  the plate  170  tips up in the back. The adjustable degree of permissible tipping is selected by the vertical position of the head  218   a  that is selected by the degree of vertical threaded engagement of the bolt  218  into the ferrule  217 . An identical stop assembly  216  can be arranged in similar fashion between the bottom wall  178  and the arm  156 . 
         [0028]    A plurality of “suitcase weights” or removable weights  220  are shown in  FIGS. 3 and 4  installed onto the spindle  75 . The weights  220  provide for an increased bracing force or reaction force via the tires of the vehicle during use of the cylinders  202 ,  206  to push against a sod strip to shift the sod strip laterally or compress the sod strip laterally. Alternative to using weights, a heavy sod roll can be carried on the spindle. 
         [0029]    Although hydraulic or pneumatic cylinders  110 ,  112 ,  202 ,  206  are mentioned, it is within the scope of the invention that other actuators can be used, such as electrically driven actuators. 
         [0030]    By retracting the cylinders  110 ,  112 ,  202 ,  206 , the apparatus  60  can be folded up and the vehicle used for another purpose. 
         [0031]    The upturned front wall  180  of the pusher plate  170  can be pushed against the sod edge for positioning. As applicable, a selectable removable strip or plate can be provided that is fastened or otherwise secured to the bottom wall  178  or to the upturned front wall  180  to accommodate pushing sod of varying thickness, such as 1 inches to 5 inches, that best matches the thickness of the sod being installed. The removable strip or plate can attach to the plate  170  and run the length of the plate  170 . In some circumstances, the plate  170  works best when the bottom wall  178  lays flat against the bare ground for ease of operation and visibility for the operator, causing little or no disruption the existing grade or ground. Different plates  170  can be attached to the arms  156 ,  158  to accommodate different situations. For example, a 4 inch thick sod requires a wider upturned front wall  180 , or an attached strip, as well as a wider bottom wall  178 , wider in the direction P, providing a larger flat area to use the ground as leverage while pushing. Other plates can also be used. 
         [0032]    Also, the plate  170  pivots at pin connections  156   a  and  158   a  which is effective for ground pressure control and allowing for angle positioning of the plate  170 , depending on the terrain. Also a side edge upturned wall  181  is sloped or curved up, like a ski or sled to accommodate pushing or sliding along the ground when the machine moves in the direction V, with minimal disruption to the ground and reduces the need to lift the apparatus  60  for repositioning. 
         [0033]    Also, the apparatus  60  can be folded up more completely by detaching the connections  110   b  and  112   b  and folding the frames  90 ,  150  up to the posts  78 ,  80  and securing thereto. 
         [0034]    The connections  106 ,  156   a ,  158   a  and similar pivotal connections or joints can comprise a through pin  280  and two engageable hairpin-shaped retainer wires  282  which insert into end pin holes through the through pin, for quick disconnect of the connection, as shown for connection  106  in  FIG. 4 . 
         [0035]    Also, for example, as shown in  FIG. 5 , an alternate plate  300  that can replace the plate  170  shown in  FIG. 2  can have spaced apart spikes  320  over its bottom surface, which extend downwardly in perpendicular fashion from a bottom wall  322 . The spikes  320  can be 1.5 inch long spikes. The spikes  320  are useful for pushing sod in a repair area in the middle of a sod area, where there is no exposed vertical edge of the sod strip to push with a plate. Thus the gripping of the spikes  320  into a top of the sod strip gives the apparatus  60  a grip on the sod strip to exert a pushing force in the direction P with respect to the apparatus  60 . 
         [0036]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. 
         [0037]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein, to the extent that the references are not inconsistent with the present disclosure.
An apparatus for a vehicle used for positioning sod strips includes a structure for mounting on the vehicle frame and a pushing plate slidably mounted to the structure. The pushing plate is arranged to be abuttable to an edge of a sod strip. A pair of cylinders are operatively mounted between the structure and the pushing plate to slide the pushing plate away from the structure to laterally shift a sod strip to tighten up seams between adjacent sod strips. A pushing frame provides arms that are slidable into base tubes of a base frame and the cylinders are connected between the arms and the base tubes to slide the pushing frame with respect to the base frame. Further cylinders are employed to pivot the base frame, the pushing frame and the pushing plate between deployed and non-deployed positions.