Patent Publication Number: US-8109313-B2

Title: Corner bead roller tool

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to wallboard finishing tools, and more specifically to corner bead roller tools for use in generally finishing corners of wallboard. 
     Corner bead products offer a thin layer of protection over the easily damaged edges of wallboard panels. The corner bead category is divided into four main segments: bare metal (nail-on), vinyl (conventional and flex roll), paper-faced bead metal and paper-faced bead plastic. A corner bead roller tool is used to accurately align the tape-on bead and squeeze out excess settable wallboard compound with greater ease and efficiency. 
     In use, a first piece of wallboard is mounted and a second piece of wallboard is mounted such that an end of the first piece abuts adjacently to an end of the second piece of wallboard to form a corner. The user will then apply wallboard compound to the corner of the wallboard in preparation of the finishing. The next step is to cover the wallboard compound with tape to form a corner of wallboard. To properly finish the corner and edge of the wallboard, the corner and tape must be pressed firmly along the corner seam of the wallboard to remove any excess wallboard compound and at the same time press the tape firmly against the wallboard to ensure a desirable finish. 
     BRIEF SUMMARY OF THE INVENTION 
     The present corner bead tool includes a bumper that extends beyond the tool bracket in order to prevent accidental damage to a wall during use. The bumper also holds a bracket nut in place such that the bracket nut is non-rotatable. A shaft rotatably attaches a roller/wheel to the bracket engaging the bracket nut without requiring an external force to hold the bracket nut during tightening. In addition, the corner bead tool provides that the shaft head is at least partially exposed from the wheel of the roller assembly to facilitate access for roller/wheel replacement. Also, the roller assembly includes wheels that have a dual taper that also allows the wheels to provide better traction against the wallboard and to facilitate removing excess wallboard compound from the corner. The wheels are connected to a bushing using a tongue-in-groove connection, which prevents longitudinal movement of the wheel with respect to the bushing and holds the wheel in place to prevent “slipping.” 
     In one embodiment, and to facilitate the finishing of wallboard, the present corner bead tool provides an elongated bracket having two ends. Each end of the elongated bracket includes a first roller assembly and a second roller assembly such that the first roller assembly includes a center axis that is perpendicular to a center axis of the second roller assembly. Each of the roller assemblies includes a wheel that is mounted to a bushing. The bushing in turn is rotatably mounted to a shaft that is connectable to the elongated bracket. The shaft is connected to the bracket utilizing a bracket nut. A bumper associated with the bracket is also included and is configured to non-rotatably capture the bracket nut. 
     In another embodiment, and to facilitate the finishing of wallboard, the present corner bead tool provides an elongated bracket having two ends. Each end of the elongated bracket includes a first roller assembly and a second roller assembly such that the first roller assembly includes a center axis that is perpendicular to a center axis of the second roller assembly. Each of the roller assemblies includes a wheel that is mounted to a bushing. The bushing is in turn rotatably mounted to a shaft that is connectable to the elongated bracket. A bumper is also included and includes a contact end surface and a portion of the bumper that extends beyond the length of the elongated bracket such that the bumper protects a wall from damage that is potentially caused by the bracket. 
     In yet another embodiment, and to facilitate the finishing of wallboard, the present corner bead tool provides an elongated bracket having two ends. Each end of the elongated bracket includes a first roller assembly and a second roller assembly such that the first roller assembly includes a center axis that is perpendicular to a center axis of the second roller assembly. Each of the roller assemblies includes a wheel that is mounted to a bushing. The bushing is rotatably mounted to a shaft that is connectable to the elongated bracket. Each wheel of each roller assembly includes a dual taper, a traction portion and a tapered end portion. The traction portion of the end of the roller assembly furthest from the bracket has less of a taper than does the tapered end of the roller assembly closest to the bracket. 
     In a further embodiment, and to facilitate the finishing of wallboard, the present corner bead tool provides an elongated bracket having two ends. Each end of the elongated bracket includes a first roller assembly and a second roller assembly such that the first roller assembly includes a center axis that is perpendicular to a center axis of the second roller assembly. Each of the roller assemblies includes a wheel that is mounted to a bushing. The bushing is rotatably mounted to a shaft that is connectable to the elongated bracket. Each wheel is mounted to each bushing utilizing a tongue and groove connection. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an embodiment of the present corner bead roller; 
         FIG. 2  is a cross-section of an embodiment of a wheel of the present corner bead roller; 
         FIG. 3  is a top view of the assembled corner bead roller of  FIG. 1 ; 
         FIG. 4  is a cross-section of an embodiment of a bushing of the present corner bead roller; and 
         FIG. 5  is a cross-section taken along the line  5 - 5  in  FIG. 3  in the direction generally indicated. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As seen in  FIG. 1 , a corner bead tool  10  in accordance with the present invention includes an elongated bracket  12 . The bracket  12  is preferably elongated and symmetrical on each end, although it is contemplated that in certain uses it may be desirable for the bracket to not be symmetrical (for example, in custom drywall corner instances). It is preferred that the bracket  12  be of a “v-shape”, such that remaining assembly can be affixed to an outside portion of the v-shape. As shown in  FIG. 1 , the bracket  12  preferably defines in a vertex an angle, “α,” of about 90 degrees. The bracket  12  may, however, also have a larger or smaller angle or be of cylindrical or triangular shape or possibly other shapes as would be contemplated by those of ordinary skill in the art and depending on the particular application. 
     It is also preferred that the bracket  12  be of a rigid, corrosion-resistant material, such as stainless steel. It is contemplated, however, that certain plastics or even wood could be used as a material of the bracket  12 . The bracket  12  is preferably rigid enough to handle variable pressure exerted by a user onto the corner bead tool  10 . For example, while less pressure may be required against the bracket  12  for applications that are within the user&#39;s reach, there may be applications where the user requires an extension pole to apply the corner bead tool  10  to taller corners or any corners that may be out of the normal arm&#39;s reach of the user. In such cases, more pressure may be required to be exerted onto the bracket  12  and it is preferred that the bracket be able to withstand such exerted pressure. 
     Attached to the bracket  12  is a protrusion or ear  14 , preferably located at the center of each wall  13  of the bracket  12 . When the bracket  12  is of a v-shape, as depicted in  FIG. 1 , it is contemplated that one protrusion or ear  14  is provided on each side of the bracket  12 . One purpose of the ear  14  is to attach an extension device, such as a handle or pole  16 , in a number of lengths, for application of the corner bead tool  10  as is known in the art and described more fully below. In addition, it is contemplated that the pole  16  may optionally include a removable extension piece. It is contemplated that any extension device as known by those of ordinary skill, can be utilized in accordance with the present tool  10 . 
     The extension device is pivotally attachable to the bracket  12  via a handle attachment  18  which pivotally engages the protrusions or ears  14 . Preferably, a rod end bearing  20  is placed between the ears  14  on the bracket  12 , such that an opening  22  in the rod end bearing  20  is aligned with openings  24  in each of the ears. Once aligned, a bracket fastener  26  such as a bolt is placed through the opening  24  of one ear  14 , then through the rod end bearing  20  and passes through the second opening  24  of a second ear  14 . The openings  24  are preferably circular and are dimensioned to receive the fastener  26 . It is contemplated that other sized and shaped openings may be used as would be appreciated by those of ordinary skill. Once passed through the second ear  14 , a lock nut  28  is affixed to the bracket fastener  26  to hold the screw in place. It is preferred that the rod end bearing  20  also include at least one spacer bushing  30  to rotatably stabilize the position of the bearing between the ears  14 . 
     Preferably, the rod end bearing  20  includes a threaded portion  32  configured for receiving an extension socket  34 , which is preferably has a threaded bore  36  configured for engaging the threaded portion  32  of the rod end bearing  20 . The socket  34  is then locked in place on the handle attachment  18  by using a nut  38 . The socket is preferably internally threaded to receive the application device  16 . It is also contemplated that other forms of attachment may be used for attaching the application device attachment handle  16  and the handle attachment  18 , such as, for example, a bayonet lock arrangement or other attachment technology as would be understood by those of ordinary skill in the art. 
     Referring again to  FIG. 1 , attached to the elongated bracket  12  are at least two roller assemblies  40 . Preferably, at least two pairs of roller assemblies  40 ,  42  are preferably equidistant from a longitudinal axis of the bracket  12  and are aligned such that the first roller assembly  40  includes a center axis that is perpendicular to a center axis of the second roller assembly  42 . It is contemplated that all of the pairs of roller assemblies  40  will have center axes that are perpendicular to the adjacent assemblies  42 . Any number of pairs of roller assemblies  40 ,  42  may be utilized based on the application and the size of the bracket  12 . 
     As an option, at least one additional roller assembly  43  is located between the first and second pairs of roller assemblies. Such additional pairs of roller assemblies prevent “bowing” of longer length brackets  12  once pressure is applied to the corner bead roller. 
     Referring to  FIGS. 1 ,  2  and  4 , each roller assembly  40 ,  42  includes a wheel  44  mounted to a bushing  46 . The bushing  46  is rotatably mounted to a shaft  48  that is connectable to the elongated bracket  12  and where the shaft  48  is connected to the elongated bracket  12  utilizing a bracket nut  50 . Each roller assembly  40  also includes a wheel  44  having a traction portion  52  and a tapered end portion  54  closer to the bracket  12 , as well as a sidewall portion  56  and an inner bore  58 . The sidewall portion  56  is located at the farthest point on the roller assembly  40  from the bracket  12 . The inner bore  58  preferably includes at least one annular rib  62  for positively and matingly engaging the bushing  46 . Alternatively, it is contemplated that the inner bore  58  may include recesses for securing to the bushing  46 . The sidewall portion  56  is optionally angled inwards and ends where the bushing  46  is inserted into the wheel  44 . 
     Each wheel  44  of each roller assembly  40  preferably includes a dual taper, where the traction portion  52  has less of a taper than does the tapered end portion  54 . The traction portion  52  of the wheel  44  is flat as it engages the wallboard for effectively flattening drywall tape onto the surface of the wallboard or other target material. The wheel  44  is preferably tapered such that the traction portion  52  has less of a taper than does the tapered portion  54  closest to the bracket  12 . While other angles are contemplated, in a preferred embodiment, each wheel  44  includes a traction portion  52  having a taper of 3°. This taper allows the roller assembly  40  to press firmly against the wallboard and press any excess wallboard compound away from the edge of the corner and facilitate finishing of the wallboard. In addition, the tapered end portion  54  preferably has a taper of greater than 3°. 
     Each wheel  44  is preferably made of a durable, soft-grip silicone to provide added traction when the tool is rolled upon a wallboard corner, especially when setting tape-on bead is provided. Traditional harder wheels have a tendency to slip when coated with joint compound. Embodiments in accordance with the present invention includes an 84° included angle β, see  FIG. 2 , straight taper and chamfered top end to match the most popular bead profiles, including outside 90° and bullnose. The wheels  44  may be color-coded by respective corner profiles, for example, black for outside 90°/superwide and PMS  356  green for bullnose. 
     As shown in  FIG. 3 , each roller assembly  40  preferably extends and is angled such that the traction portion  52  of each roller assembly  40  extends past the length of the bracket  12 . In this way, the amount of wallboard that is pressed by the corner bead tool  10  of the present invention is not limited to where the bracket  12  stops the tool  10  before the bracket  12  hits and causes damage to the wallboard. 
     As shown in  FIGS. 1 and 4 , affixed in an inner bore  58  of each wheel  44 , each bushing  46  includes an insertion end  64 , at least one groove  66  for positively and matingly engaging the annular ribs  62  and a shaft engagement end  68 . The ends  64 ,  68  are reversible since the bushing  46  is symmetrical. It is contemplated that each bushing  46  includes at least one and preferably two grooves  66 . The mating tongue-in-groove engagement between the ribs  62  and the grooves  66  prevents the relatively softer silicone on the wheel  44  from shifting relative to the relatively harder plastic bushing  46 . Alternatively, it is contemplated that the bushing  46  may include at least one protrusion to engage a recess in the inner bore  58  of the wheel  44 . It is also contemplated that any combination of protrusions and grooves may be used to secure engagement between the wheel  44  and the bushing  46 . In addition to the above arrangement, chemical adhesive or other supplemental fastening techniques is optionally provided. 
     Referring to  FIGS. 1 and 5 , each shaft  48  includes a threaded tip  70 , a shank  72  and a head  74 . The threaded tip  70  is inserted into the shaft engagement end  68  of the bushing  46  and pushed through a throughbore  75  in the bushing  46  until the threaded tip  70  passes through an aperture  76  in the elongated bracket  12 . The bracket nut  50  is then used to affix the shaft  48  to the bracket  12 . Once the shaft  48  is installed, the bushing  46  rotates relative to the shaft  48 . 
     Once secured, the head  74  of the shaft  48  remains at least partially exposed or extends beyond a length of the wheel  44  such that the head  74  is accessible for tightening or loosening by a user of the corner bead roller  10  using a standard wrench. 
     A bumper  78  is configured for non-rotatably capturing the bracket nut  50 . The bumper  78  is located on the opposite side of the walls  13  of the bracket  12  with respect to the roller assemblies  40 ,  42 . A recess  80  is provided on the bumper  78  to non-rotatably capture the bracket nut  50 . As shown in  FIG. 1 , the bumper  78  has two recesses  80 , configured to capture each bracket nut  50  from a corresponding pair of roller assemblies  40 ,  42  mounted perpendicularly onto the bracket  12 . 
     As shown in  FIG. 3 , the bumper  78  also includes a top surface  82 , opposite the bracket nut recesses  80  that face the bracket  12 . In addition, the bumper  78  includes a contact end surface  84  and an opposite surface  86 . The contact end surface  84  of the bumper  78  functions as a shock absorber and engages the wallboard prior to the bracket  12  hitting the wallboard during application. As shown in  FIG. 3 , it is contemplated that the contact end surface  84  of the bumper  78  extends beyond the bracket  12  the same amount as traction portion  52  of each of the roller assemblies  40 . In this way, the bumper  78  does not impede the pressing action of the roller assemblies. 
     While a particular embodiment of the present corner bead tool has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.