Abstract:
The invention is a vehicle tow bar for self-powered aerators for grassy areas, such as golf courses. U-shaped members attached to the tow bar slide over the front axle housing of the self-powered aerator and allow the aerator to be towed swiftly from place to place using a tow vehicle, speeding the golf course aeration process. A corresponding method also is provided.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/218,082 filed Jul. 13, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to a self-propelled aerator, particularly to a type having at least one axle and used for performing maintenance of grassy areas at golf courses, and, more particularly, to a tow bar for a self-propelled aerator.  
           [0004]    2. Description of the Prior Art  
           [0005]    Tow bars are well known in the art and are of varied types for use with distinct types of vehicles. Examples of tow bars for particular use with recreational vehicles include those disclosed in U.S. Pat. No. 5,873,595 issued Feb. 23, 1999 and in U.S. Pat. No. 5,516,140 issued May 14, 1996, both to Hinte; in U.S. Pat. No. 5,429,382 issued Jul. 4, 1995 and U.S. Pat. No. 5,147,095 issued to Sep. 15, 1992, both to Duncan. Examples of tow bars for use with automobiles or trailers include those disclosed in U.S. Pat. No. 5,277,446 issued Jan. 11, 1994 to Hamel; in U.S. Pat. No. 5,240,273 issued Aug. 31, 1993 to Stead et al.; in U.S. Pat. No. 4,958,847 issued Sep. 25, 1990 to Williams; and in U.S. Pat. No. 4,147,373 issued Apr. 3, 1979 to Cully. An example of a tow bar for use with a snowmobile is disclosed in U.S. Pat. No. 3,797,846 issued Mar. 19, 1974 to Pevic. An example of an aircraft tow bar is disclosed in U.S. Pat. No. 3,829,131 issued Aug. 13, 1974 to Moore, Jr. Examples of tow bars for three-wheeled vehicles are disclosed in U.S. Pat. No. 4,736,963 issued Apr. 12, 1988 to Bettencourt and in U.S. Pat. No. 4,170,370 issued Oct. 9, 1979 to Schaefer.  
           [0006]    However, these prior art devices are not particularly suitable for towing a piece of golf course maintenance equipment that is self-propelled and called variously an aerator or an aerifier. During the fall and again in the early spring, golf courses perform several maintenance operations to their greens and fairways to keep-the grass healthy and full. An important maintenance operation is called variously aeration or aerification, a process by which openings are made in the turf so that the underlying soil is exposed to the air and receives oxygen. To aerate their lawns, golf courses generally use a motorized unit of equipment called an aerifier or aerator. Although aerators can range in size, an ordinary golf course aerator is sized similarly to a riding lawn mower. Typically, it is a four-wheeled vehicle that may be self-propelled. Aerators that are not self-propelled are designed for use with a tractor and/or riding mower. Such aerators are typically mounted onto a hitch provided in the front of the tractor or riding mower and moved under the power of the tractor or mower. On the other hand, self-propelled aerators are typically gasoline powered and operated by a golf course technician operates who walks behind it and guides its direction. They are not engineered to be mounted onto the hitches provided on various tractors and riding mowers.  
           [0007]    As a self-propelled aerator is guided over the lawn, an array of coring tines arranged in a specific pattern and of a certain width ranging from 4½ to 7 feet (1.37 to 2.13 m) punches holes into the turf, the depth of which typically from three to five inches (7.62 to 12.7 cm). Tine diameters vary from ¼ to ⅞ inch (0.6 to 2 cm). Typically, the array of tines is disposed around a wheel or wheels that are rolled over the area to be aerated.  
           [0008]    Aerators are generally slow moving vehicles, with normal operating speeds between 3 to 5 miles per hour. Typical aerators of fairways and other large turf areas can aerate about 1.5 to 1.75 acres per hour and aeration acreage rates for rougher turf areas are lower.  
           [0009]    Its slow pace, while required to thoroughly aerate a grassy area, limits the usefulness of an aerator during the biennial maintenance periods. Since greens and fairways are often separated by relatively large distances, transporting an aerator under its own power from one green or fairway to another can take more time than the aeration process itself. Consequently, aeration by self-propelled aerators can often take an unnecessarily long period of time, which results in inefficient use of labor and extra expense.  
           [0010]    Therefore, it is (desirable to have a tow bar that can connect a self-propelled aerator to another vehicle that can transport the aerator between spread-out and distant turf areas on a golf course at speeds greater than at which the aerator operates.  
         SUMMARY OF THE INVENTION  
         [0011]    This invention provides a tow bar that is configured to be attached to a self-propelled aerator that has at least one wheel axle and to a powered vehicle that transports the self-propelled aerator at speeds greater than the aerator can attain under its own power and which reduces the lateral movement of the aerator during towing over uneven terrain. The invention also provides a method wherein a self-propelled aerator having at least one wheel axle is transported at speeds greater than under its own power by being attached to a powered towing vehicle and then having the towing vehicle transport it to a desired location.  
           [0012]    It is a principal feature of the present invention to provide an aerator tow bar adapted to attach a towing vehicle to a self-propelled aerator having at least one wheel axle. Additionally, the present invention features a tow bar adapted to reduce the lateral movement of such an aerator as the towing vehicle transports it over uneven terrain or rough turf. Another feature of this invention is the provision of such a tow bar that is of simplified construction for economical manufacture, maintenance and repair.  
           [0013]    It is also a principal feature of the invention to provide a method for towing a self-propelled aerator by: attaching the tow bar of this invention to a towing vehicle and to a self-propelled aerator having at least one wheel axle; and then transporting the aerator to the desired location.  
           [0014]    An advantage of the present invention is that the self-propelled aerator may be transported to a desired location in the golf course at much greater speeds than under its power and thereby reduce the total time for aerating a golf course. The method of towing a self-propelled aerator has the advantage of increasing employee productivity, improving overall timely sequencing of equipment and personnel and thereby reducing the overall expense for performing golf course maintenance.  
           [0015]    The foregoing and other advantages and features of this invention will appear from the following detailed description, taken in connection with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view of the tow bar of the present invention.  
         [0017]    [0017]FIG. 2 is a detail of the means for connecting the tow bar to a aerator.  
         [0018]    [0018]FIG. 3 is a partial perspective view showing connection of the tow bar to the front axle housing of a self-propelled aerator.  
         [0019]    [0019]FIG. 4 is a first alternative embodiment showing a clevis pin connection to a towing vehicle.  
         [0020]    [0020]FIG. 5 is a second alternative embodiment showing a hook connection to a towing vehicle.  
         [0021]    [0021]FIG. 6 is a third alternative embodiment showing a trailer hitch connection to a towing vehicle. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]    A vehicle tow bar  2  (FIG. 1) provides for releasable attachment to the front end of a self-propelled aerator  4  (FIG. 3) to be towed and to the rear end of a towing vehicle (not shown). Tow bar  2  comprises three distinct sections: the means  6  for attaching the tow bar  2  to the self-propelled aerator  4 , the means  8  for attaching the tow bar  2  to the towing vehicle and the cross member  10  that connects these two means.  
         [0023]    The means  6  for attaching the tow bar to the aerator  4  comprises two parallel U-shaped bars  12  and a spring mechanism  14 . The U-shaped bars  12  define an axle-receiving opening  16  and are designed to slide over and past the axle housing  18  (FIG. 3) of the aerator  4  so that the curved portion  20  of the bars  12  rest on the axle housing  18 . The U-shaped bars  12  are configured so that the straight portions  22  of the bars  12  extend several inches past the aerator axle housing  18 . The U-shaped bars  12  are set apart from each other so as to slide over and rest onto the axle housing  18  between the two front wheels  24  of the aerator  4 .  
         [0024]    The U-shaped bars  12 , and hence the tow bar  2 , are secured to the aerator  4  by an aerator latch springbar  26 . Initially, the aerator latch springbar  26  is urged into a first (closed) position by aerator latch spring  28  pressing against an aerator latch spring stop  30 . Pulling aerater latch handle  32  causes the aerator latch springbar  26  to move away from the axle-receiving opening  16  to a second (open) position. The aerator latch spring stop  34  attached to the aerator latch springbar  26  presses against and compresses the aerator latch spring  28 . Releasing the aerator latch handle  32  allows the aerator spring  28  to urge the aerator latch springbar  26  back to the first (closed) position.  
         [0025]    In attaching the tow bar  2  to the aerator  4 , the U-shaped bars  12  slide over the aerator axle housing  18  and the aerator latch handle  32  is pulled, thereby compressing the aerator latch spring  28  and moving aerator latch springbar  26  into the second (open) position. The U-shaped bars  12  are positioned so that the axle housing  18  passes into the axle receiving opening  16  and the U-shaped bars rest on the front wheel axle housing  18 . Aerator latch handle  32  is released, thereby allowing aerator latch spring  28  to urge aerator latch springbar  26  into the first (closed) position. The length of aerator latch springbar  26  is adapted to the diameter of the front wheel axle housing  18 .  
         [0026]    The movement of the aerator latch springbar  26  into the first (closed) position causes the aerator latch springbar  26  to create, in concert with the U-shaped bars  12 , a space that accommodates the front wheel axle housing  18 , thereby “capturing” the axle housing  18  into a constrained space. Capturing the axle housing  18  minimizes lateral movement of the axle housing  18  against the tow bar  2  and consequently minimizes the lateral movement of the aerator  4  during transport over uneven terrain.  
         [0027]    With reference to FIG. 1, the means  8  for attaching the tow bar  2  to the towing vehicle comprises a tow latch spring mechanism  36 , which includes a tow latch housing  38 , a tow latch springbar  40  attached to a tow latch handle  42  and a tow latch spring  44  that is coiled around tow latch springbar  40 . A tow latch spring stop  46  limits the travel of the tow latch springbar  40  and transmits force from the tow latch housing  38  to the tow latch springbar  40 .  
         [0028]    The tow latch springbar  40  is initially in a first (closed) position. To mount the tow bar  2  to a towing vehicle, tow latch handle  42  is pulled, thereby urging tow latch spring stop  46  against tow latch spring  44 , compressing tow latch spring  44  and retracting tow latch springbar  40  to a second (open) position. The tow latch housing  38  then is placed in mating apposition to a hitch of a towing vehicle (not shown). The tow latch handle  42  is released, allowing the tow latch spring  44  to urge the tow latch springbar  40  back into the first (closed) position. As the tow latch springbar  40  returns to the closed position, the tow latch springbar  40  passes through a mating hole in the hitch of the towing vehicle, securing the tow bar  2  to the towing vehicle. A clevis pin  48 , hook  50 , trailer hitch  52  (FIGS. 4 through 6) or any suitable mechanism can be substituted for the tow latch spring  44  and tow latch springbar  40  for connection of the tow bar  2  to the towing vehicle.  
         [0029]    With reference to FIG. 3, the invention includes a method for aerating a golf course using a self-propelled aerator  4  and a towing vehicle, which includes the following steps:  
         [0030]    (1) Operating the aerator is a self-propelled manner to aerate a desired area of a golf course;  
         [0031]    (2) providing a tow bar as described above;  
         [0032]    (3) removably securing the tow bar to the front wheel axle housing of the self-propelled aerator and to a towing vehicle;  
         [0033]    (4) driving the towing vehicle with the secured self-propelled aerator to another grassy area in the golf course, which is desired to be aerated;  
         [0034]    (5) removing the tow bar between the self-propelled aerator and the towing vehicle;  
         [0035]    (6) operating the aerator in a self-propelled manner to aerate the grassy area.  
         [0036]    Many different embodiments of the above invention are possible. This application is intended to address all possible embodiments and is limited only as described in the following claims.