Abstract:
A trimmer head accessory comprising a (i) head with brush bristles on its underside and (ii) attachment hardware is disclosed. The attachment hardware may comprise (i) a spacer cup, (ii) a washer, and (iii) a set of fasteners. The head and attachment hardware are designed so that the present invention can be used to convert virtually any trimmer into an rotary scrubbing tool. The tool can be used for cleaning driveways, patios, garages, wood decks, walls, and even indoor surfaces.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to accessories for use with trimmers.  
         [0003]     2. General Background  
         [0004]     Trimmers are now a common tool used by many Americans in their home or garden. In the past, trimmers have been used for only one purpose: cutting or trimming weeds or grass. Trimmers have thus been an underutilized tool, since the spinning shaft that drives the trimmer&#39;s cutting head can be used for many other purposes. Thus, rather than just a single use tool, the trimmer can operate as platform for many different accessories. The present invention is one example of such an accessory, namely a rotating brush that can be attached to virtually any gasoline trimmer.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention is a trimmer head accessory comprising a (i) head with brush bristles on its underside, and (ii) attachment hardware. The attachment hardware may comprise (i) a spacer cup, (ii) a washer, and (iii) a set of fasteners. The head and attachment hardware are designed so that the present invention can convert virtually any gasoline trimmer into an rotary scrubbing tool. The tool can be used for cleaning driveways, patios, garages, walls, wood decks, and even indoor surfaces.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is an exploded front perspective view of a trimmer head accessory according to an embodiment of the present invention.  
         [0007]      FIGS. 2 and 3  show a trimmer head accessory according to an embodiment of the present invention being attached to a trimmer head that contains a spool housing.  
         [0008]      FIGS. 4 and 5  show a trimmer head accessory according to an embodiment of the present invention being attached to a trimmer head from which the spool housing has been removed.  
         [0009]      FIG. 6  is a top view of a trimmer head accessory according to an embodiment of the present invention.  
         [0010]      FIG. 7  is a bottom view of a trimmer head accessory according to an embodiment of the present invention.  
         [0011]      FIG. 8  is a cross section view taken along line  8 - 8  of  FIG. 6  of a trimmer head accessory according to an embodiment of the present invention, as attached to a trimmer head from which the spool housing has been removed.  
         [0012]      FIG. 9  is the same as  FIG. 8 , except that it shows a trimmer head accessory according to an embodiment of the present invention as attached to a trimmer head with a spool housing.  
         [0013]      FIG. 10  shows an exemplary set of fasteners to be provided with a kit according to an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0014]     The present invention is a trimmer head accessory comprising a (i) head  30  with bristles  52  on its underside, and (ii) attachment hardware.  
         [0015]     The head  30  has a annular plate  50  and a tapered protrusion  32 . See  FIGS. 1-9 . The tapered protrusion  32  is hollow and forms a head recess  34  on the underside of the head. See  FIGS. 7, 8 , and  9 . A boss  38  descends from the top of the tapered protrusion  32  into the head recess  34 . See  FIGS. 8 and 9 . The boss  38  has a recess (the boss recess) within it, and within this recess a protective insert  40  may be placed. See  FIGS. 1, 7 ,  8  and  9 . This protective insert  40  may be in contact with the nut  42  or other fastener that attaches to the trimmer&#39;s threaded shaft  62  or  74 . See  FIGS. 1, 8  and  9 .  
         [0016]     A central aperture  36  extends through the center of the tapered protrusion  32 , and into the boss recess in the boss  38  through the protective insert  40 .  
         [0017]     Bristles  52  are attached on the underside of the annular plate  50 . See  FIGS. 1, 3 ,  5 ,  7 ,  8 , and  9 .  
         [0018]     Thus, the head  30  has bristles  52  on the peripheral region of its underside, and a head recess  34  in the central region of the head&#39;s  30  underside. See  FIG. 7 . On its top side, the head has a protrusion  32  in its central region, and an annular plate in its peripheral region. See  FIG. 6 .  
         [0019]     The attachment hardware of the present invention includes a spacer cup  10 , a washer  20 , and a set of fasteners  80 . The spacer cup  10  is hollow, and is used to install the device when the trimmer&#39;s spool housing cannot be removed. See  FIGS. 1-3 , and  8 .  
         [0020]     Typically, only one fastener is needed to attach the head  30  to any given trimmer. However, an entire set  80  of diverse fasteners should be provided, so that the head can be attached to virtually any trimmer, regardless of the size or nature of the shaft. Thus, the fasteners may be nuts for attachment to externally threaded shafts, or bolts to attach to internally threaded shafts, or any other means for attachment to a shaft. An exemplary set  80  of fasteners is shown in  FIG. 10 . If nuts or bolts are used, they will typically be hexagonal. Special nuts or bolts may need to be machined to accommodate certain trimmers. In a typical kit, there may be 12 to 20 fasteners.  
         [0021]     While the fasteners need to fit with various sizes and configurations of trimmer head shafts, they also need to have uniform head size to snugly fit into the recess of the boss  38 . Thus, while the “internal dimensions” (the shaft diameter for the bolts and the bore size for the nuts) of the fasteners will vary from fastener to fastener, the “external dimensions” (the size and shape of the bolt heads and the periphery of the nuts) must be remain constant, and must conform to the dimensions of the recess within the boss  38 . See  FIG. 10 . In this way, a single device can be used with many different types of trimmers. The pitch, size, orientation (left handed or right handed), and number of threads per inch for the fasteners can vary depending on the particular application.  
         [0022]     In operation, the brush head is first attached to the shaft of the trimmer. There are two attachment methods, depending on whether the trimmer&#39;s spool housing is removed or not.  
         [0023]     If the housing is removed, then the procedure depicted in  FIGS. 4 and 5  is used. In this procedure, the housing  72  is removed from the trimmer head base  70 , leaving the exposed threaded shaft  74 . See  FIG. 4 . Then the head  30  is placed on the shaft  74 , and an appropriate nut  42  or other fastener is threaded on the shaft to secure the head  30  to the trimmer. Typically, no tools are required. The trimmer has thus been converted to a rotary brush, and is ready for use.  FIG. 8  is a cross section view of this embodiment.  
         [0024]     Alternatively, if the spool housing  60  need not be removed, then the spool is removed, exposing the threaded shaft  62  within a recess of the spool housing  60 . See  FIG. 2 . The spacer cup  10  is then placed within this recess and through the threaded shaft  62 . See  FIG. 2 . A washer  20  can then placed over the shaft  62 , and the head  30  can be placed atop the washer  20 , with the threaded shaft extending through the central aperture  36  into the recess of the boss  38 . See  FIG. 3 . An appropriate nut  42  or other fastener is then threaded on the shaft to secure the head  30  to the trimmer, without the need for a wrench or similar tool.  
         [0025]     Once the head  30  is installed on the trimmer, the device is ready for use. The trimmer is operated in the usual way, but instead of causing a cutting head to rotate, the trimmer&#39;s shaft now causes the brush to rotate, thereby transforming the trimmer into a scrubbing tool.  
         [0026]     The present invention can be used with most any gasoline trimmer, and also with certain electric trimmers. The present patent is not limited to trimmers of any particular configuration or drivetrain, except as provided by the express language of the claims.  
         [0027]     The components of the present invention can be manufactured of many different materials, including but not limited to plastics and other polymers and metals.  
         [0028]     One skilled in the art will appreciate that the present invention can be practiced by other than the preferred embodiments, which are presented for purposes of illustration and not of limitation. Thus, although the present patent has focused on attaching a rotary scrubber to a trimmer, the present invention can be used to attach virtually any trimmer accessory to a trimmer, where “accessory” is defined to include all trimmer head attachments besides cutting heads.