Patent Publication Number: US-2007101584-A1

Title: Head cover trimming system

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application represents a divisional application of U.S. patent application Ser. No. 10/645,574 filed Aug. 22, 2003, pending. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention pertains to the art of grass trimmers and, more particularly, to a grass trimming system for cutting grass around a substantially ground level head cover, such as a sprinkler head of an underground irrigation system.  
      2. Discussion of the Prior Art  
      Many grass covered areas, such as public parks, dog parks, ball fields and, particularly, golf courses are provided with underground sprinkler or irrigation systems, as well as other ground level objects such as yardage markers and drain covers. Underground sprinklers are used for a variety of reasons, such as convenience, safety and aesthetics as they do away with unsightly hoses and sprinklers that lay about the landscape. Typically, an underground sprinkler system includes a plurality of independently controlled zones each having an associated plurality of sprinkler heads. The zones may be manually activated for a undetermined period or, more commonly, through a central controller that establishes particular on and off times, as well as a desired duration of each “on” time. In any case, the sprinkler heads are generally positioned even with, or slightly below, ground level so as to allow a lawn mower to pass over head without causing damage to the sprinkler head. When activated, the sprinkler head will “pop-up” either partially, or fully above the ground to emit a stream of water that is directed over a prescribed area.  
      As the sprinkler heads are mounted at or below ground level, grass growing around the sprinkler head may grow too close thereby preventing the sprinkler head from operating correctly. Moreover, as the sprinkler heads are periodically trod upon or, for that matter, driven upon by lawn equipment, dirt can build up around the head and also interfere with normal operation. Towards that end, landscape maintenance people and groundskeepers must periodically trim around the sprinkler heads. When choosing a tool to trim around the sprinkler heads, there is a wide array of choices. However, all the trimming tools fall into one of two general categories: manual and motor driven.  
      Manually operated trimming tools typically consist of a main shaft having a handle provided at one end, and a cutting blade at the other. The cutting blade is centered over the sprinkler head and the handle rotated to cut or trim the grass. While effective, manual trimming tools are a bit unwieldy, and are also a bit slower than their motor-driven counterparts which, like the manually operated trimming tool, typically include a shaft having a cutting head mounted at one end. However, unlike manually operated tools, the opposite end of the shaft is either connected to a powered trimmer or driven by a rotary tool, such as a battery operated drill. In operation, the cutting head is placed over the sprinkler head and the powered trimmer or rotary tool activated, thereby driving the cutting head to cut the grass. While also very effective, the powered trimmers currently available are difficult to center over the sprinkler head. Often times, the cutting head will cut an asymmetrical area around the sprinkler. If the tool is not centered correctly, the cutting head could detrimentally impact the sprinkler head itself or, for that matter, underlying water piping or even electrical wiring that could render the sprinkler head inoperable. Similar problems exist in connection with trimming around other ground level head cover structures, such as yardage markers, drain covers and the like.  
      Based on the above, there still exists a need in the art for an enhanced head cover trimming system for cutting grass around a sprinkler head. More specifically, there exists a need in the art for a trimming system for ground level head covers in general, including, in addition to sprinkler heads, drain covers, golf course yardage markers and the like.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to a head cover trimming system, including a head cap and a grass trimmer for cutting grass around a sprinkler head or the like. When employed in connection with a sprinkler head, the sprinkler head includes a housing having a top cover portion and a cylindrical body portion, with the head cap being arranged on the top cover. More specifically, the head cap includes a main body portion having a bottom surface fixedly secured to or integrated into the top cover portion of the housing cover and a top surface including a centering member.  
      In accordance with a preferred embodiment of the present invention, the grass trimmer includes a head member having a substantially circular outer peripheral edge portion interconnected to a central hub through an intermediate portion. More specifically, the head member is sized to fit over a typical sprinkler head or another ground level head cover object, such as a yardage marker or drain cover. A drive shaft member interconnects the head member with a rotary tool, such as a cordless drill, that, when operated, rotates the head member cutting the grass and generally trimming the area around the head cover.  
      In accordance with a more preferred form of the invention, the grass trimmer includes a central centering shaft that extends centrally from within the head member and projects below the outer peripheral edge portion. When the head member is placed over the head cover, the centering shaft is received by the centering member of the head cap. Preferably, the centering member is constituted by a recessed portion sized to receive the centering shaft. With this arrangement, the head member is centered about the head cover permitting a clean cut. Moreover, with this particular arrangement, the head member cannot become off-center, thereby ensuring that the cutting element will not damage the head cover.  
      In accordance with the most preferred embodiment of the present invention, the centering shaft is adapted to retract into the head member. Actually, the centering shaft retracts into a centering shaft housing that is centrally positioned within the head member. In this manner, the head member can travel downward into the ground making a slightly deeper cut, thus not only trimming the grass but, also edging the area around the head cover.  
      Obviously, the head cover trimming system is adaptable to a wide range of applications. More specifically, the head cover trimmer can be used to trim about a broad array of circular or substantially circular ground level objects embodying a head cap in accordance with the invention. For instance, the head cap could be mounted upon, for example, sprinkler heads, drain covers, yardage markers, or valve access ports. Moreover, each of the aforementioned objects could be integrally formed with a corresponding centering member in order to receive the center shaft of the head trimmer.  
      Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an area about a hole at a golf course showing a head cover trimming system constructed in accordance with the present invention poised above a sprinkler head;  
       FIG. 2  is a upper perspective view of a head cap portion of the overall head cover trimming system;  
       FIG. 3  is an elevational view of the head cap of  FIG. 2 ;  
       FIG. 4  is an upper perspective view of a head cover trimming assembly portion of the overall head cover trimming system of the present invention;  
       FIG. 5  is a cross-sectional elevation view of the head cover trimming assembly of  FIG. 4 ;  
       FIG. 6  is an exploded view of the head cover trimming assembly of  FIG. 4 ;  
       FIG. 7  is a partial perspective view of the head cover trimming assembly of  FIG. 4  positioned above a sprinkler head;  
       FIG. 8  is a perspective view of the head cover trimming system descending down over the sprinkler head with a centering shaft portion of the grass trimming system entering a centering member of the head cap;  
       FIG. 9  is a perspective view of the head cover trimming system cutting grass and edging around the sprinkler head; and  
       FIG. 10  is a perspective view of the sprinkler head after the grass trimming and edging has been completed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      With initial reference to  FIG. 1 , the present invention is generally shown for use at a green  1  of a golf course. To this end,  FIG. 1  depicts a hole  2  having extending therefrom a pin  3  associated with green  1 . About green  1  is a higher cut grassy area generally referred to as a “first cut”  4 . Located in first cut  4  is a buried sprinkler head assembly  6 . In the embodiment shown, sprinkler head  6  includes a main housing  10  having a top cover  12  and a cylindrical body  13 . It should be initially noted that the use of sprinkler head assembly  6  in connection with green  1  only represents a single use of the invention. As will become more fully apparent from the following detailed discussion of the invention, sprinkler head assembly  6  can be employed in a wide range of environments wherever an underground sprinkler system is employed.  
      In a manner known in the art, sprinkler head assembly  6  will be caused to spray water in a predetermined pattern, with sprinkler head  6  either remaining stationary or rotating during operation. Actually, when water is supplied to sprinkler head assembly  6 , a central portion (not separately labeled) of top cover  12  lifts or “pops-up” above the ground to spray water in the predetermined pattern. Once the water supply is stopped, top cover  12  retracts into main housing  10  so as to be at or below ground level. Over time, grass and dirt can build up around sprinkler head assembly  6  preventing top cover  12  from lifting when the water is supplied. In that case, the surrounding grass will not receive the required amount of irrigation. Towards that end, the area around the sprinkler head must be maintained, that is the grass and dirt build-up must be periodically removed to ensure proper operation of each sprinkler head assembly  6 . Accordingly, groundskeepers or maintenance people periodically trim the area around each sprinkler head  6 . In accordance with the present invention, a head cover trimming system indicated generally at  20  is employed for this purpose.  
      In accordance with a preferred embodiment of the present invention, head cover trimming system  20  includes a head cap  24  and a grass trimming assembly  30 . More specifically, grass trimming assembly  30  includes a cutting head system  34  connected to a drive shaft  40 . Drive shaft  40  is also connected to a rotary tool  42  which, in the embodiment shown, is depicted as a cordless drill. However, it should be understood that various other mechanisms could be used to operate grass trimming assembly  30 , such as corded drills, as well as gas and electric powered trimmers. It should also be understood that, although the invention is being described in connection with the preferred embodiment of trimming about a sprinkler head, the term “head cover” is used to describe any circular or substantially circular ground level cover including a drain cover, yardage marker and the like. In any event, as will be detailed more fully below, grass trimming assembly  30  is adapted to cooperate with head cap  24  to ensure a clean cut around main housing  10  while at the same time preventing cutting head system  34  from accidentally damaging top cover  12  or other components of sprinkler head assembly  6 .  
      Referring to  FIGS. 2 and 3  illustrating one preferred form of the present invention, head cap  24  includes a main body portion  52  having a bottom surface  54  and a top surface  55 . In accordance with the invention, a centering member  58  is positioned centrally on top surface  55 . In the embodiment shown, centering member  58  is constituted by a central recess  59  having an upper receiver or tapered portion  60  extending to a cylindrical bore  61  which leads to a terminal end portion  62 . As will be detailed more fully below, centering member  58  is adapted to cooperate with corresponding structure on grass trimming assembly  30  so as to position cutting head system  34  about main housing  10 . Top surface  55  of head cap  24  is also provided with a plurality of recessed portions  64  and  65  which enable information plates, such as a plate indicating the yardage remaining to hole  2  or other information relating to the particular zone in which the particular sprinkler head  6  to be incorporated into head cap  24 .  
       FIGS. 4-6  illustrate a preferred embodiment of cutting head system  34 . As shown, cutting head system  34  includes a head member  76  having an outer peripheral edge portion  78  leading to an upper, central hub  80 . Extending between outer peripheral edge portion  78  and central hub  80  is an intermediate portion  82  which, in the embodiment shown, includes a peripheral or circular side wall section  85  that leads to a tapered section  86 . As shown, tapered section  86  extends to central hub  80 . As further shown, tapered section  86  includes a plurality of vented openings  90  which, as will be detailed more fully below, generates an air flow within head member  76  to draw away and expel cut grass from about sprinkler head assembly  6 . In addition, positioned at or about outer peripheral edge portion  78  of head member  76  is a cutting element  94  which, in the embodiment shown, is constituted by a circular blade having a plurality of lower teeth  95  for both cutting grass and edging about sprinkler head assembly  6 .  
      In accordance with a preferred embodiment of the present invention, head member  76  is removably secured to drive shaft  40 . As shown, drive shaft  40  includes a driven end  96  that extends to a driving end  98 . Driving end  98  terminates in a plate portion  100  that, as will be detailed more fully below, is secured to head member  76 . In a manner known in the art, driven end  96  is provided with one or more flats  102  which limit the possibility of slippage when driven end  96  is placed into a chuck portion (not separately shown) of rotary tool  42 . In any event, plate  100  is provided with a plurality of radially spaced holes  106 - 109  that align with a corresponding plurality of holes  112 - 115  arranged on central hub  80 . With this arrangement, head member  76  is detachably secured to drive shaft  40  using a plurality of mechanical fasteners indicated generally at  117 , in combination with lock washer  118  and nuts  119 .  
      In accordance with the most preferred form of the present invention, cutting head system  34  is provided with a central, centering shaft  130  adapted to cooperate with centering member  58  of head cap  24 . As shown, centering shaft  130  includes a first end  131  mounted centrally within head member  76  leading to a second end  132  having arranged thereon a positioning ring  133 . Positioning ring  133  is actually sized to cooperate with upper tapered portion  60  of central recess  59  in order to locate centering shaft  130  with respect to head cap  24 . Centering shaft  130  is actually retractably positioned within head member  76 . Towards that end, a centering shaft housing  136  is centrally supported within head member  76 . More specifically, centering shaft housing  136  includes a first end  140  secured with central hub  80  through mechanical fasteners  117 , a second end  141  and a hollow, cylindrical, main body portion  142 . As best seen in  FIGS. 5 and 6 , arranged within centering shaft housing  136  are a pair of upper and lower bearings  146  and  147  that provide support for a centering shaft retainer  150 . As shown, first end  131  of centering shaft  130  is retractably received by centering shaft retainer  150 . In addition, arranged within centering shaft retainer  150 , between second end  131  of centering shaft  130  and central hub  80 , is a spring  151  which outwardly or downwardly biases centering shaft  130 . In addition, in order to prevent centering shaft  130  from becoming cocked in centering shaft retainer  150 , a bushing  154  is fitted around first end  131 . With this arrangement, centering shaft  130  can slide or easily retract into centering shaft retainer  150  without becoming misaligned and jamming.  
      In further accordance with the most preferred embodiment of the present invention, head member  76  is provided with a cutting element holder  160  that is detachably secured to outer peripheral edge portion  78 . In the embodiment shown, cutting element holder  160  includes an upper edge portion  163  and a lower edge portion  165  which preferably define a central recess  166  adapted to receive cutting element  94 . More specifically, upper edge portion  163  is provided with a plurality of tab elements, one of which is indicated at  170  in  FIGS. 4 and 6 , that are adapted to snap-fittingly engage into a corresponding plurality of slots  180  arranged about side wall section  85  of head member  76 .  
      Referring to  FIGS. 7-10 , the manner in which cutting head system  34  cuts grass around sprinkler head assembly  6  will now be described. Initially, it should be understood that the term “trimming” is used broadly and therefore refers not only to cutting blades of grass but to edging the area about sprinkler head assembly  6  as well. In any event, to initiate a trimming process, cutting head system  34  is positioned over sprinkler head assembly  6  as represented in  FIG. 7 . Cutting head system  34  is then lowered onto sprinkler head assembly  6  so that centering shaft  130  is received by centering member  58 . In this manner, cutting blade  94  is properly positioned or centered about sprinkler head assembly  6  before cutting begins as represented in  FIG. 8 . After cutting blade  94  is properly centered, a downward force is applied to cutting head assembly  34  causing centering shaft  130  to retract into centering shaft housing  136  against the biasing force of spring  151 . Once cutting head system  34  is properly centered and positioned about sprinkler head assembly  6 , a driving force is applied to driven end  96  of drive shaft  40  ( FIG. 9 ). In turn, driving end  98  of drive shaft  40  rotates cutting head system  34  about sprinkler head assembly  6 , thereby trimming grass, dirt and other foreign objects from around top cover  12  and cylindrical body  13 . As cutting head system  34  rotates, vented openings  90  create a vortex-like airflow that expels the cut grass from within head member  76 . In addition, it should be noted that the rotation of cutting head system  34  is not imparted to centering shaft  130 . That is, the presence of bearings  146  and  147  allows centering shaft  130  to remain stationary with respect to cutting head system  34 . With this construction, centering shaft  130  will not wear away or otherwise damage centering member  58  which, over time, would result in centering problems. Upon completion of the trimming operation as illustrated in  FIG. 10 , cutting head assembly  34  is raised from sprinkler head assembly  6  allowing centering shaft  130  to return to an extended position under the biasing force of spring  151 . As described, this overall operation will leave behind a well maintained sprinkler head which, when supplied with water, should operate normally.  
      Obviously, the above description detailing the operation of head cover trimming system  20  trimming grass about sprinkler head assembly  6  is but one preferred application. It should be apparent that cutting head system  34  is readily adaptable to a wide range of applications. That is, any circular or substantially circular ground level cover can be fitted with a head cap  24  so as to accommodate cutting head system  34 . In this manner, drain covers, yardage markers and valve access covers, to list but a few, can be trimmed with the trimming system of the present invention. Moreover, each of the aforementioned objects could actually be formed with a centering member so as to receive the centering shaft of cutting head system  34 .  
      Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, while head cap  24  is illustrated as an integral part of the overall trimming system, cap  24  may be also provided separately. That is, head cap  24  may be provided as a retrofit part to adapt existing sprinkler heads for use with the cutting head system of the present invention. For instance, head cap  24  may be secured to sprinkler head assembly  6  with glue, mechanical fasteners, double sided tape or the like. Furthermore, while centering member  58  is described as a recess, other structure, such as cylindrical pins, multiple recesses or protrusions that would cooperate with associated centering structure on the cutting head assembly, would also be acceptable. In general, the invention is only intended to be limited to the scope of the following claims.