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FIELD OF THE INVENTION  
       [0001]     The invention relates to drywall construction. More specifically, the invention relates to a device for applying drywall mud or joint compound to corner beads or tape-on-trims prior to their attachment to joints or corners between adjacent drywall panels.  
       BACKGROUND OF THE INVENTION  
       [0002]     Corner beads are elongate, narrow strips of metal, plastic, or metal with a paper face on one side, or the like, folded or angled along their longitudinal center line, or along a line offset from the center line in some cases, to produce a generally v-shaped cross-section. They are made in various angles and corner shapes, including sharp 90 degree angle corners, sharp corners at other angles, rounded or so-called “bullnose” corners of various angles, and offset or L-shaped corners. Corner beads are also designed for covering both inside (concave) and outside (convex) corners. For application to an inside corner, drywall mud is applied to the outside (convex) faces of an inside corner bead. For application to an outside corner, drywall mud is applied to the inside (concave) faces of an outside corner bead. Joint compound is applied to the appropriate faces of the bead, and the bead is then pressed against the corner, with the joint compound forming an adhesive joint between the bead and corner.  
         [0003]     Although drywall mud or joint compound may be applied to corner beads by hand, this is a time consuming and inconvenient process. Hopper devices have been proposed in the past for applying joint compound to the inside faces of an outside corner bead. One such apparatus is described in U.S. Pat. No. 5,169,449 of Raught. The apparatus comprises a hopper with a V-shaped trough in its base, and triangular shaped end walls at opposite ends of the trough forming a generally V-shaped gap between the lower edge of each end wall and the trough. Removable end panels are adjustably secured to the end panels to adjust the height of the gap. A corner bead is fed through the base of the hopper from one end wall opening to the opposite end wall opening, and drywall mud in the hopper will be applied to the upwardly facing surfaces of the corner bead. All except a thin layer will be scraped off by the edge of the end panel as the corner bead exits the hopper. Removable liners may be placed into the hopper to define different trough cross-sectional shapes, corresponding to different shapes of corner bead, and associated with end panels with corresponding edge shapes.  
         [0004]     Other systems have been designed which allow joint compound to be applied to either the inside or outside faces of the corner for applying the corner bead to inside or outside corners. For example, U.S. Pat. No. 6,907,908 discloses a hopper apparatus for applying joint compound to corner beads that has a hopper for holding a quantity of joint compound and a feeder apparatus secured across the lower end of the hopper. The feeder apparatus has a channel and a series of elongate feeder inserts for selectively securing in the channel. A first set of outside feeder inserts each have a generally V-shaped indented groove extending along their length for guiding an outside corner bead through the feeder apparatus, while a second set of inside feeder inserts each have a generally V-shaped ridge extending along their length for guiding an inside corner bead through the feeder. The feeder inserts in each set have grooves and ridges of different angles and corner shapes matching those of a plurality of different inside and outside corner beads and are releasably secured in the channel.  
         [0005]     One problem with prior art hoppers having corner bead feeders for applying joint compound is that they are used with hoppers that must be filled and then emptied with every use or the drywall compound within the hopper will become too dry to work with. This represents lost time and tedious work to a drywall finishing professional. Moreover, prior art devices for applying drywall compound to a corner bead use panels which scrape the excess drywall compound from the corner bead to obtain the desired surface for coating. However, in the past it has been thought that thin panels were most advantageous, perhaps due to the abrasiveness of drywall compound. However, thin panels allow drywall to escape as the hopper sits, particularly when the hopper is full of compound, and if corner bead is pulled through on an angle, the thin panels will deflect to wipe of excessive amounts of compound.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention comprises a device for applying drywall compound to a length of corner bead. The device comprises a trough for holding a quantity of drywall compound and an opening at the bottom of the trough through which a length of corner bead may be inserted. A removable block is located near an opening in the trough having a plurality of grooves located therein for preventing excess drywall compound from adhering to the bead while allowing sufficient compound to remain with the bead. A flange attached to the top of the trough is adapted to be attached to a bucket, the bucket having a portion of the bottom removed, to provide drywall compound to the trough. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a top view of an apparatus according to a preferred embodiment of the invention;  
         [0008]      FIG. 2  is a bottom view of an apparatus according to a preferred embodiment of the invention;  
         [0009]      FIG. 3  is front view of an apparatus according to a preferred embodiment of the invention with its legs in a first, extended position;  
         [0010]      FIG. 4  is a front view of an apparatus according to a preferred embodiment of the invention with its legs in a second, retracted position;  
         [0011]      FIG. 5  is a front view of a side plate of a leg of the apparatus according to a preferred embodiment of the invention;  
         [0012]      FIG. 6  is a right side view of an apparatus with a block removed according to a preferred embodiment of the invention with its legs in a first, extended position;  
         [0013]      FIG. 7  is a right side view of an apparatus with a block inserted according to a preferred embodiment of the invention with its legs in a first, extended position;  
         [0014]      FIG. 8A  is a front view of a block according to a preferred embodiment of the invention;  
         [0015]      FIG. 8B  is a side view of a block according to a preferred embodiment of the invention;  
         [0016]      FIG. 9  is a front view of a pin according to a preferred embodiment of the invention;  
         [0017]      FIG. 10  is a view of a container with the apparatus according to the preferred embodiment of the present invention applied thereto resting upon a second container;  
         [0018]      FIG. 11  is a view of a container with the apparatus according to the preferred embodiment of the present invention applied thereto placed within the second container;  
         [0019]      FIG. 12  is a perspective view of a bottom block according to a preferred embodiment of the invention;  
         [0020]      FIG. 13  is a top view of the device with a bottom block inserted therein according to a preferred embodiment of the invention;  
         [0021]      FIG. 14  is a front view of a block according to another embodiment of the invention;  
         [0022]      FIG. 15  is a front view of a block according to another embodiment of the invention;  
         [0023]      FIG. 16  is a perspective view of a block of  FIG. 15 ;  
         [0024]      FIG. 17  is a perspective view of a block of  FIG. 16 ; and  
         [0025]      FIG. 18  is a side view of a block and a bottom block according to an embodiment of the present invention adapted for bullnose corner beads. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.  
         [0027]     Referring to  FIG. 1 , the present invention comprises an apparatus  10  for applying drywall compound to a length of corner molding. The apparatus  10  includes a top plate  12  comprising a circular plate defining a central opening  14 . The top plate  12  has a top surface  18  and includes a plurality of bores  16  generally evenly spaced about the circumference of the top plate  12 .  
         [0028]     As shown in  FIG. 2 , attached to a bottom surface  20  of the top plate  12  are two pairs of flanges  22  and  24 . The pairs of flanges  22  and  24 , which may also be provided as a single assembly, are preferably attached by welding an extension  25  of the flange  22  or  24  to the top plate  12 . The flanges  22  and  24  each define through-bores (not shown) through which fasteners  26  are inserted. The fasteners  26  also extend through through-bores (not shown) located in a pair of rotatably attached legs  28  and  30 .  
         [0029]     The legs  28  and  30  each comprise a pair of side plates  32  attached to one another with a pair of bars  34 . The side plates  32  have a profile as shown in  FIG. 5 , which includes a bucket rest cutout  33 . Adjacent the bucket rest cutout  33  is a safety hook portion  37  which keeps the side plates  32  in association with the buckets, as described below. The legs  28  and  30  are rotatable about the fasteners  26  between a first, extended position as shown in  FIG. 3  where the legs  28  and  30  rest against stops  35  on the flanges  22  and  24  and a second, retracted position as shown in  FIG. 4  where the legs  28  and  30  contact one another.  
         [0030]     A V-shaped trough  36  is also attached to the bottom side  20  of the top plate  12 . The trough  36  covers the central opening  14 . Ends of the trough  36  are open as viewed in  FIG. 6 , but the end openings are partially covered by end plates  38  extending from the top plate that are located inboard of an outer edge of the trough  36 . A cutout  39  is located in each end plate  38 .  
         [0031]     Placed in the ends of the trough  36  are blocks  40  ( FIGS. 8A and 8B ). Referring to  FIGS. 6 and 7 , the blocks  40  fit within the end openings and against the end plates  38 . The blocks  40  generally conform to the end openings of the trough  36  also include a recessed portion  39  that forms a gap  42  near a bottom  44  of the trough  36 . Referring back to  FIGS. 8A and 8B , grooves  46  are formed in the bottom of the blocks  40  ( FIG. 8A ). The blocks  40  are preferably made from a phenolic material which is rigid and can withstand the abrasiveness of drywall compound. The gap  42  between the block  40  and the trough  36  is preferably about ¼″ or 3/16″ and the grooves  46  are preferably ⅛″ deep. Additionally, the block  40  is preferably about 1½″ thick. It has been discovered that a thicker block  40  prevents drywall compound from being easily forced through the gap  42  when the apparatus  10  is not being used. The blocks  40  preferably removably held in place by pins  48  ( FIG. 9 ) that extend through the trough  36  and through a bore  100  in the block in the block  40 . A block  40  not defining grooves  46  may also be used on one side of the trough  36 . The block  40  is further located ¼″ or more from the edge of the trough in order to provide a surface of the trough  36  upon which to rest the corner bead or make alignment and insertion of the corner bead easier into the gap  42  easier. Moreover, the block  40  defines a second bore  102  in the block  40  which is located at a different vertical height to provide for a different width gap.  
         [0032]     Finally, it is preferred that corner bead support flanges  44  are attached to either side of the trough with the pin  48 . The corner bead support blocks  44  help support corner bead as it is fed through the apparatus.  
         [0033]     Referring to  FIGS. 11 and 12 , the apparatus  10  of the present invention is used by taking a common five-gallon bucket  104  in which drywall compound is normally delivered and cutting a hole in the bottom of the bucket that at least conforms to the size of the opening  14 . The top plate  12  is then attached to the bottom of the bucket  104  of drywall with fasteners, as shown in  FIG. 10 . In this manner a common five-gallon drywall bucket is used as a hopper for the apparatus  10 , containing drywall compound which by the force of gravity falls into the trough  36 . The common five gallon bucket  104  further includes a lid which can be replaced on the bucket  104  between uses so that that hopper of the apparatus does not need to be emptied and cleaned between uses.  
         [0034]     The apparatus  10  is used by inserting a length of drywall corner bead into one end of the trough  36  and pushing it through the trough  36  until it extends out the other end of the trough  36 . The drywall compound within the trough  36  adheres to top surface of the corner bead, and the corner bead is pulled through the trough  36  until its full length has gone through the trough  36 . On the exit end of the trough  36 , the gap  40  formed by the recess  39  allows an appropriate amount of drywall compound to exit the trough  36  adhered to the corner bead. The grooves  46  further allow raised beads of drywall compound to exit the trough  36  on the corner bead. In this manner drywall compound is applied to the surface of the corner bead.  
         [0035]     Referring to  FIG. 11 , in order to bring the apparatus  10  up to an appropriate working height, the legs  28  and  30  are placed in the position shown in  FIG. 3  and placed on top of a second, preferably empty five gallon bucket  106  of the type in which drywall compound is normally delivered. The second bucket  106  further acts as a receptacle to drywall compound that falls off of the corner bead as it is pulled through in order to minimize mess.  
         [0036]     Moreover, the second empty bucket  106  is utilized as a storage receptacle for the apparatus  10 . By placing the legs  28  and  30  in the position of  FIG. 4 , the first bucket  104  serving as the hopper and the apparatus can be set into the second bucket  106  as shown in  FIG. 12 . In this manner, the first bucket  104  can be sealed with its lid and the apparatus placed into the second bucket  106  and the apparatus does not have to be emptied of drywall compound and cleaned for storage between uses because drywall compound portions of the apparatus  10  will be sealed from air and therefore the drywall compound within first bucket  104  and the trough  36  will not dry out.  
         [0037]     While present invention is described with the trough having the profile of an inverted triangle as shown in  FIGS. 6 and 7 , it is within the skill of one of ordinary skill in the art that the drywall trough and the block can take on any appropriate form for different type of corner bead and for applying drywall compound to an opposite side of the corner bead for applying, for example, compound to inside corners, bull nose corners, ells and end caps.  
         [0038]     The preferred embodiment of the present invention also comprises a bottom block  50  as shown in  FIG. 13 . The bottom block  50  is placed in the bottom of the trough  36  and, as shown in  FIG. 14 , causing the bottom of the tough  36  to be convex rather than concave. Extensions  51  cooperate with the trough to hold the bottom block  50  in place.  
         [0039]     Referring to  FIGS. 15-18 , the blocks  40  are replaced with block  52  and block  54 . The block  54  defines a plurality of grooves  56  in a concave portion of the block  54 . The blocks  52  and  54  may optionally also comprise a tapered portion  58  for guiding the corner bead through the device. By using the bottom block  50  and the blocks  52  and  54 , drywall compound may be applied to the other surface of the corner bead so that the corner bead can be applied to inside rather than outside corners.  
         [0040]     Referring to  FIG. 19 , the blocks  40  are replaced with blocks  60 , which are modified to have a convex curved bottom surface  62  to handle outside bullnose corner beads. The bottom block  50  is similarly replaced with bottom block  64  which has a concave curved surface  66  that corresponds to the convex surface  62 . Similarly, it will be understood by one of ordinary skill in the art that the block  40  and bottom block  50  can have the appropriate profile to handle corner bead of most any profile used as inside or outside corner beads.  
         [0041]     While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.

Summary:
A device for applying drywall compound to a length of corner bead. The device comprises a trough for holding a quantity of drywall compound and an opening at the bottom of the trough through which a length of corner bead may be inserted. A removable block is located near an opening in the trough having a plurality of grooves located therein for preventing excess drywall compound from adhering to the bead while allowing sufficient compound to remain with the bead. A flange attached to the top of the trough is adapted to be attached to a bucket, the bucket having a portion of the bottom removed, to provide drywall compound to the trough.