Abstract:
A tool is provided for filling a gearbox with lubricant. The tool includes structure which prevents the gearbox from being over filled with lubricant. The tool of this invention enables access to the fill opening of the gearbox and prevents spillage or leakage. The tool is ideally suited for use with a gearbox mounted on the drive unit of a mechanized irrigation system.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a tool for filling a gearbox with lubricant and more particularly to the tool for filling a gearbox, mounted on a drive unit of a mechanized irrigation system, with liquid lubricant. 
         [0003]    2. Description of the Related Art 
         [0004]    In mechanized irrigation systems such as a center pivot irrigation system, the water pipeline is propelled around a field by a plurality of spaced-apart drive units or towers with each of the drive units having a pair of driven wheels. Normally, a gearbox is associated with each of the drive wheels with the gearboxes being driven by an electric motor or the like. The gearbox is filled with a liquid lubricant and it is extremely important that the lubricant in the gearbox be maintained at the proper level. Prior to the instant invention, the filling of the gearbox with lubricant required the use of long funnels of hoses to direct the flow of lubricant to the fill hole of the gearbox with the fill hole being at a location having limited access because of the associated drive wheel. The fill holes on some gearboxes are difficult to fill using common equipment. When a gearbox becomes full, any extra lubricant in the funnel being used may leak as it is removed from the fill hole. If the gearbox is overfilled with lubricant, the reduced air volume within the gearbox may cause increased pressure inside the gearbox and force lubricant through the seals of the gearbox creating a leak. 
       SUMMARY OF THE INVENTION 
       [0005]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter. 
         [0006]    A tool for filling a gearbox mounted on a drive unit of a mechanized irrigation system with liquid lubricant is disclosed with the gearbox having a fill hole extending horizontally thereinto below the upper end thereof. The tool of this invention comprises a funnel-like member having an open upper end with a discharge opening at the lower end thereof. A generally vertically disposed first hollow tubular portion, having open upper and lower ends, extends downwardly from the discharge opening of the funnel-like member. A generally horizontally disposed second hollow tubular portion is in communication with the lower end of the first tubular portion. The second tubular portion has a downwardly presented first discharge opening formed therein inwardly of the closed outer end thereof. A third hollow tubular portion, having inner and outer ends, is selectively rotatably mounted on the second tubular portion. The third tubular portion has a second discharge opening formed therein. The second and third tubular portions are adapted to be inserted into the fill opening of the gearbox to seal the fill opening. The second discharge opening is in fluid communication with the first discharge opening when the third tubular portion is rotated to a fill position with respect to the second tubular portion. The second discharge opening is out of fluid communication with the first discharge opening when the third tubular portion is rotated to a fluid shut-off position with respect to the second tubular portion. 
         [0007]    In the preferred embodiment, the center of the funnel-like member is laterally offset with respect to the first tubular portion so that the tool may be easily used adjacent the tire of the drive unit. 
         [0008]    When the second and third tubular portions are inserted into the fill opening of the gearbox, lubricant is placed into the funnel-like member if lubricant has not been previously placed therein. The third tubular portion is then rotated with respect to the second tubular portion so that the first and second discharge openings in the second and third tubular portions respectively are in register with one another. The design of this invention permits lubricant to only reach the full level and prevents over filling. This is achieved by the location of the first discharge opening. During the filling of the lubricant, the lubricant level will only rise to the bottom of the first discharge opening. At that point, air cannot escape from the gearbox and additional lubricant will not flow into the gearbox, thus preventing over filling. Because the gearbox cannot be over filled with lubricant, the air volume therein will be maintained. Pressure will not be increased and lubricant will not be forced through the seals thereby creating leaks. 
         [0009]    It is therefore a principal object of the invention to provide an improved tool for filling a gearbox with lubricant. 
         [0010]    A further object of the invention is to provide a tool for filling a gearbox with lubricant with the gearbox being mounted on a drive unit of a mechanized irrigation system. 
         [0011]    A further object of the invention is to provide a tool for filling a gearbox with lubricant which ensures that the gearbox will not be over filled with lubricant. 
         [0012]    A further object of the invention is to provide a tool for filling a gearbox with lubricant which prevents spillage of the lubricant. 
         [0013]    These and other objects will be apparent to those skilled in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
           [0015]      FIG. 1  is a perspective view of a conventional mechanized irrigation system on which gearboxes are mounted for driving the drive wheels of the drive units; 
           [0016]      FIG. 2  is a partial perspective view illustrating a typical gearbox employed on a drive unit of a mechanized irrigation system; 
           [0017]      FIG. 3  is a perspective view of the tool of this invention; 
           [0018]      FIG. 4  is a partial exploded perspective view of a portion of the tool of this invention; 
           [0019]      FIG. 5  is an exploded perspective view of the tool of this invention; 
           [0020]      FIG. 6  is a side view of the tool of this invention with the tool being in the “off” or closed position; 
           [0021]      FIG. 7  is a partial sectional view illustrating the tool of this invention being in its closed or shut-off position; and 
           [0022]      FIG. 8  is a view similar to  FIG. 7  except that the tool has been rotated so that fluid may be discharged from the funnel-like member. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    Embodiments are described more fully below with reference to the accompanying figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense in that the scope of the present invention is defined only by the appended claims. 
         [0024]    The numeral  10  refers generally to a mechanized irrigation system such as a center pivot irrigation system. The system  10  conventionally includes a center pivot structure  12  having a main water pipeline  14  extending outwardly therefrom. The pipeline  14  includes a plurality of span structures. Each of the drive units  18  includes a main beam  20  having drive wheels  22  and  24  rotatably mounted on the opposite ends thereof. Usually, a gearbox  26  is provided for each of the drive wheels  22  and  24  with the gearboxes  26  being driven by an electric motor so that the irrigation system may be propelled through the field about the center pivot structure. Although a center pivot irrigation system  10  is illustrated, the gearbox lubricant fill tool of this invention may be employed on other mechanized irrigation systems such as a linear move irrigation system, a corner irrigation system, etc. 
         [0025]      FIG. 2  illustrates a typical gearbox  26  to which the drive wheel hub  28  is attached. The gearbox  26  includes a lower end  30  and an upper end  32 . Gearbox  26  includes a selectively closable lubricant fill opening  34  which extends horizontally into the gearbox  26  as seen in  FIGS. 7 and 8 . As seen in  FIGS. 2 ,  7  and  8 , the fill opening  34  is formed in gearbox  26  below the upper end thereof. 
         [0026]    The fill tool of this invention is refined to generally by the reference numeral  38 . Tool  38  includes a funnel-like member  40  having an open upper end  42 . The lower end of member  40  is open and has a first hollow tubular portion  44  extending downwardly therefrom in an offset relationship with respect to the center of the funnel-like member  40  as best seen in  FIG. 6 . A second hollow tubular portion  46  is in fluid communication with the lower end of first tubular portion  44  and extends horizontally therefrom. The end  48  of tubular portion  46  is closed as seen in  FIGS. 7 and 8 . Tubular portion  46  has a downwardly presented discharge opening  50  formed therein adjacent the closed end  48 . 
         [0027]    The numeral  52  refers to a third hollow tubular portion having a closed end  54  and an open outer end  56 . A circular disc  58  is formed with tubular portion  52  and extends transversely outwardly therefrom as seen in  FIG. 4 . Rotation or actuation lever  60  is also formed with tubular portion  52  and disc  58  and extends radially therefrom. Tubular portion  52  has an opening  62  formed therein adjacent inner end  54  and which is axially or radially aligned with lever  60  to assist the operator in visually determining the rotational position of opening  62  by simply lo observing the position of lever  60 . A pair of O-ring seals  64  and  66  embrace annular grooves formed in tubular portion  52 . 
         [0028]    Tubular portion  52  selectively rotatably embraces tubular portion  46  as illustrated in the drawings. Tubular portion  52  is selectively rotatable from a first “closed” position wherein opening  62  is out of register with opening  50  in tubular portion  46  ( FIG. 7 ) to a second “open” or fill position wherein opening  62  registers with opening  50  ( FIG. 8 ). 
         [0029]    The method of using the tool of this invention is as follows. When it is desired to fill the gearbox  26  with lubricant, the plug closing the fill opening  34  is removed. The lever  60  on the tubular portion  52  is rotated to the position of  FIG. 3  so that the opening  62  does not communicate with the discharge opening  48  in tubular portion  46 . The funnel-like member  42  is then filled with liquid lubricant. The tool  38  is then maneuvered so that the tubular portion  52 , which has the tubular portion  46  contained therein, is inserted into the fill opening  34  so that disc  58  embraces the outer surface of the upper end of the gearbox  28  as illustrated in  FIG. 2 . 
         [0030]    The tubular portion  52  is then rotated from the position of  FIG. 5  to the position of  FIG. 8  so that discharge opening  62  registers with discharge opening  48  as seen in  FIG. 8 . The lubricant contained within the funnel-like member  42  will then flow into the upper end of the gearbox through the openings  50  and  62 . When the lubricant level reaches discharge opening  62 , further lubricant will not flow into the interior of the gearbox thereby ensuring that the gearbox will not be overfilled. When the gearbox has been suitably filled with lubricant, the tubular portion  52  will be rotated from the position of  FIG. 8  to either the position of  FIG. 7  or to the position of  FIG. 5  with the attitude of the lever  60  indicating the relative position of the opening  62  with respect to the opening  50 . 
         [0031]    When the tubular portion  52  has been rotated to either the position of  FIG. 7  or the position of  FIG. 5 , the tool  38  is moved laterally with respect to the fill opening  34  so that the tubular portion  52  is removed from the fill opening  34  with the plug, which normally closes the fill opening  34 , then being replaced into the fill opening. 
         [0032]    It can therefore be seen that a tool has been provided for filling a gearbox mounted on a mechanized irrigation system to be conveniently filled with lubricant and which prevents spillage of lubricant and which also prevents the gearbox from being overfilled with lubricant. 
         [0033]    It can therefore be seen that the invention accomplishes at least all of its stated objectives. 
         [0034]    Although the invention has been described in language that is specific to certain structures and methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed invention. Since many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.