Abstract:
A drywall bazooka for dispensing flexible trim material such as FLEXTRIM and ULTRALITE products, or any other flexible trim material, containing a head attached to an elongated handle, a drive wheel attached to the head for pulling the trim material from a roll, at least one roller for pressing the trim material into an interior or exterior corner and a cutter for cutting the trim material. A pair of rollers can be attached to a ferris wheel assembly to be swung into position for interior or exterior corners. The interior roller can resemble a pizza knife, and the exterior roller can be cylindrical of varying diameter shaped like two intersecting cones.

Description:
[0001]     This application is related to and claims priority from U.S. Provisional patent application No. 60/499,798 filed Sep. 3, 2003. Application 60/499,798 is hereby incorporated by reference. 
     
    
     BACKGROUND  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to the field of drywall corner bead application and more particularly to a drywall bazooka that applies flexible corner bead.  
         [0004]     2. Description of the Prior Art  
         [0005]     It is well known in the field of drywall installation to use a device called a bazooka to string drywall tape to seams. The bazooka is a combination drywall mud and tape dispenser that is attached to a long handle. The bazooka is filled with drywall mud and a roll of drywall tape. The device applies drywall tape along flat seams simply running the device along the seam.  
         [0006]     Drywall corners, both exterior and interior, on the other hand, are usually finished with drywall corner beads. This process has been done by hand in the past by either nailing the bead in place and then mudding it, or by mudding and pressing the bead in place. Most corner beads must be sanded after the applied mud is dry. An example of a bead that does not require sanding is a family of products called FLEXTRIM (R) and ULTRAFLEX (R) sold by Drywall Systems International, Inc. This product can simply be applied onto wet mud, pressed into position, and finally have the tapered edges feathered with a small amount of mud and a drywall knife. The outer surface of the trim is prepared to directly receive paint or texture as soon as the mud dries. No sanding, or very little sanding, is necessary.  
         [0007]     What is badly needed is a bazooka type device that can dispense a flexible corner bead onto an exterior or interior corner.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention relates to a drywall bazooka for dispensing flextrim bead for both interior and exterior angles. The bazooka can contain a base mounting member with an elongated handle, a head member attached to the base member with the head member containing a drive wheel for pulling flextrim product from a roll and feeding it onto a drywall corner seam and at least one blade wheel also attached to the head member where the blade wheel presses the flextrim product into the seam and the blade wheel can be a disk like a pizza blade for an interior seam or a pair of conical members for an exterior corner.  
         [0009]     The blade wheel for an exterior corner can be made with pair of cones intersecting along a central axis and aligned along the axis. The blade wheels can be attached to a ferris wheel arrangement that is in turn attached to the head, where the ferris wheel arrangement holds the interior blade wheel on one end and the exterior blade wheel on the other end. This allows the ferris wheel to be used to rotate one of said blade wheels into position for use. It is also possible to have removable drive wheels where they can be interchanged for different types of trim product.  
         [0010]     The bazooka of the present invention can also have a cutter attached to the head member for cutting the flextrim product. The cutter can be powered, spring-loaded or manual, or can be any other type of cutter capable of cutting the flextrim.  
     
    
     DESCRIPTION OF THE FIGURES  
       [0011]      FIG. 1  shows a side-on view of an embodiment of the invention.  
         [0012]      FIG. 2  shows an embodiment of a head.  
         [0013]      FIG. 3  shows a front looking view of the head of  FIG. 2 .  
         [0014]      FIG. 4A  shows a side view of the interior/exterior ferris wheel.  
         [0015]      FIG. 4B  shows a front view of the ferris wheel of  FIG. 4A .  
         [0016]      FIG. 5  shows an embodiment of the invention being used to lay exterior flex trim.  
         [0017]      FIG. 6  shows an embodiment of the invention being used to lay interior flex trim.  
         [0018]      FIG. 7  shows an embodiment of a head with a spring-loaded cutter and the ferris wheel in position for an interior corner.  
         [0019]      FIG. 8  shows the embodiment of  FIG. 7  with the ferris wheel in position for an exterior corner.  
         [0020]      FIG. 9  shows an embodiment of a head with a manual cutter. 
     
    
       [0021]     It should be noted that various figures and illustrations have been presented to aid in the understanding of the present invention. The scope of the present invention is not limited to the embodiments shown in the figures.  
       DESCRIPTION OF THE INVENTION  
       [0022]     Turning to  FIG. 1 , an embodiment of the present invention is shown that includes a long handle  10 , a head  8 , a ferris wheel arrangement with two roller blade wheels: an interior roller  2  and an exterior roller  4 . A strip of flexible trim material  6  is shown passing through the device.  
         [0023]     The operation of the embodiment of  FIG. 1  can be seen  FIGS. 5-6 .  FIG. 5  shows the bazooka of the present invention laying down a strip of exterior drywall flexible trim  6 . The ferris wheel double head  14  is set so that a conical blade wheel  4  fits the drywall flextrim  6  to the corner.  FIG. 6  shows the same operation on an interior corner with a piece of interior flextrim  6 . Here the interior roller blade wheel  2  presses the flextrim into the corner. The interior blade wheel can resemble a pizza cutter.  
         [0024]     Returning to  FIG. 1 , a technician can hold the bazooka by the long handle  10  and move it down the seam. The flextrim  6  feeds off of a roll and can be cut when needed. Mud can optionally be applied by the present invention or the seam can be pre-mudded. The preferred method is to have the bazooka deliver the mud. When the end of the run is reached, the trim can be cut by any type of cutter.  FIG. 5  shows a spring-loaded cutter  13  attached to the head  8 . Any type of cutter is within the scope of the present invention.  
         [0025]      FIG. 2  shows a detail of the head  8  and the attached wheels. A larger feed wheel  1  causes the rolled flextrim to feed off the roll and into the seam. The flextrim passes above the large feed wheel  1  in  FIG. 2 . A ferris wheel arrangement  14  includes a shaft  11  that pivots on a bolt or rod  3  and is loaded with a roller blade wheel at each end. The first end holds an interior seam blade wheel  2 ; the second end holds an exterior seam blade wheel  4 .  
         [0026]     An alternative to a ferris wheel arrangement is direct replacement of one blade wheel by another for the correct type of corner.  
         [0027]     Because the nature of flextrim is very different from drywall tape, the blade wheels of the present invention are unique. Normally flextrim is made of high impact plastic, while drywall tape is usually paper. As can be seen in  FIGS. 5-6 , the flexible trim material or bead is dispensed in a manner similar to drywall tape in a conventional bazooka.  
         [0028]      FIG. 3  shows a front-on view of the roller blade wheels and the drive wheel  1 . The flextrim is pulled off of a roll and fed by the drive wheel  1  which is held in the head housing  8 . The drive wheel  1  can have teeth on its outside edges as shown in  FIG. 3  to pull the flextrim product from the roll and drive it into the seam. In some embodiments of the present invention, the drive wheel  1  can be removable and changed out for different types of flextrim products.  
         [0029]     A lower part of the structure  12  shown in  FIG. 3  can be attached to a pivot point  3  which can be a bolt or rod. This pivot point  3  can define the ferris wheel arrangement. The interior blade wheel  2  and the exterior blade wheel  4  (rollers) can be seen sideways in  FIG. 3 .  
         [0030]      FIG. 4A  shows a side view of the ferris wheel arrangement, while  FIG. 4B  shows a front view. Both roller blade wheels are round; however, the interior wheel  2  is narrow in order to force the flextrim into an interior corner. The exterior wheel  4  is generally wide and can be formed from the intersection of two cones. The unique shapes of the rollers cause them to exactly fit the seam they are being used for. In particular, the continuously linearly changing diameter from center to outside causes the tool to exactly fit the shape of an exterior corner. The blade wheels  2 , 4  are preferably made from aluminum; however, any solid material can be used including steel and plastic. The blade wheels can be made any convenient dimensions and the exterior blade wheel  4  can have any convenient slope. The preferred slope is around 46 degrees since a standard exterior corner is around 90 degrees. The preferred diameter of the exterior blade wheel  4  is around 2 inches, while the preferred diameter of the interior blade wheel  2  is slightly smaller. In general, the angle of the exterior blade wheel  4  should be chosen to match that of the wall.  
         [0031]     It should be noted that the ferris wheel arrangement is optional, and that blade wheels can be made removable in various embodiments of the present invention. In this case, blade wheels can be chosen to match particular job requirements. In particular, blade wheels can be used that match any interior or exterior angle.  
         [0032]     The bazooka of the present invention can optionally contain a lever to make the device move out from a wall.  
         [0033]     It should be noted that the flextrim material or flexible bead can be made any width with a preferred width of around 3¼ inches for outside corners. Different blade wheels can be used for trim of different widths.  
         [0034]     As previously stated,  FIG. 5  shows an embodiment of the present invention being used to lay down an exterior corner.  FIG. 6  shows the same embodiment being used to lay down an interior corner.  
         [0035]      FIG. 7  shows a side perspective view of a slightly different embodiment. Most of the features previously described can be seen. In addition, a cutter  13  is shown which can be used to cut the trim. The cutter  13  shown in  FIG. 7  is a spring-loaded cutter that can be activated with a trigger. Any type of cutter is within the scope of the present invention including spring-loaded, manual pull, power driven and any other kind of cutter capable of cutting flextrim.  FIG. 9  shows an embodiment with a manual cutter.  
         [0036]      FIG. 7  also shows the ferris wheel arrangement with the interior blade wheel  2  in position for use.  FIG. 8  shows the embodiment of  FIG. 7  with the exterior blade wheel  4  in position for use.  
         [0037]     Several descriptions and illustrations have been presented to aid in the understanding of the present invention. A person skilled in the art to which the present invention relates will understand that many changes and variations are possible. All of these changes and variations are within the scope of the present invention. In particular, the present invention can be used to lay down any type of flexible trim on any corner of any angle. Different roller blade wheels and drive wheels can be used and exchanged. These can be removable or fixed. The blades can be made from any material and can be any shape necessary to conform to any type of trim product. The handle assembly can be any length and can contain an inner handle that moves the unit to a different angle or activates a cutter. The unit can be used with or without a cutter, and any type of cutter can be used including powered cutters, spring-loaded cutters, manual cutters and any other cutter that will cut the trim or bead material being used. A cutter can be activated in any possible way including a rod, a trigger, automatically or any other way. The present invention can be made from any rigid material.