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CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Provisional application Ser. No. 60/312,917, filed Aug. 16, 2001, for Tape and Joint Compound Dispenser for Taping Drywall Joints. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a drywall or wallboard tape and joint compound dispenser or taping gun. More specifically, the present invention relates to a taping tool or taper for use in applying tape and joint compound to drywall or wallboard joints. 
     2. Description of the Prior Art 
     Taping tools or applicators have been in use in the drywall installation industry for many years. One manufacturer of such a device is Wallboard Tool Co., Inc. of Long Beach Calif., which has since as early as 1994, sold a product identified as the “Wal-Board ‘Quick-Load’ Drywall Taper.” The Wal-Board taper has a box or housing defining an interior chamber containing drywall joint compound. Drywall joint tape from a roll supply carried on the box is passed through the chamber in which it receives a coating of joint compound. The coated tape is then applied to a wallboard or drywall joint. The tool is refilled with the joint compound when necessary by opening the box cover, using both hands to lift the wet tape carefully away from the bottom of the chamber, and then adding a supply of joint compound to the chamber between the tape and the bottom of the chamber. 
     A self-loading drywall tape applicator is shown in U.S. Pat. No. 3,707,427. Drywall joint compound is supplied by a pump from a hopper to the joint compound chamber of the tool through which drywall tape is passed for the application of joint compound thereto and the subsequent application of the coated tape to a drywall joint. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied in a tape gun for applying joint tape and joint compound to drywall joints. The taper is formed by a housing having opposed side walls spaced apart a width determined by the width of the drywall tape being applied, and peripheral top, bottom, and end walls. The housing defines therein a chamber for holding joint compound for application to the tape. The housing further defines an entrance slot in one end wall opening into the chamber for receiving tape for the application of joint compound thereto, and an exit slot for supplying tape with joint compound thereon to the drywall joint. The chamber has an upper arcuate top wall and a lower elongated bottom wall. 
     A tape lifter is swingably mounted in the housing chamber and extends into the chamber between the tape entrance slot and the tape exit slot. When the tape gun is in use, the lifter is positioned adjacent the lower chamber wall with the tape positioned between the lifter and the upper chamber wall. 
     For actuating the tape lifter, a handle is swingably mounted exteriorly on the housing and is operatively connected to the tape lifter for swinging the lifter to lift the tape and position it against the upper wall of the chamber. The handle retracts the lifter to position the same adjacent the bottom wall of the chamber. 
     The housing further defines in one wall a valved port through which joint compound is introduced into the chamber below the lifted tape. In this manner, joint compound can be supplied to the chamber through the port and below the tape for subsequent application to the tape as the tape passes through the slots for application to drywall joints. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left front perspective view of the tape and joint compound dispenser embodying the present invention. 
     FIG. 2 is a right front perspective view thereof. 
     FIG. 3 is a right rear perspective view thereof. 
     FIG. 4 is a left rear perspective view thereof. 
     FIG. 5 is a top plan view thereof. 
     FIG. 6 is a bottom plan view thereof. 
     FIG. 7 is a front elevation view thereof. 
     FIG. 8 is a rear elevation view thereof. 
     FIG. 9 is a right end view thereof. 
     FIG. 10 is a left end view thereof. 
     FIG. 11 is a section view taken substantially in the plane of line  11 — 11  on FIG.  5  and showing the lifter in retracted position. 
     FIG. 12 is a view similar to FIG. 11 but showing the lifter in a partially raised position. 
     FIG. 13 is a view similar to FIG. 11 but showing the lifter in a further raised position. 
     FIGS. 14A-D are a diagrammatic series of illustrations showing the lifting of the tape by the tape lifter. 
     FIGS. 15A-D are a diagrammatic series of illustrations showing retracting of the lifter, loading of the joint compound and application of the tape and joint compound to the wallboard joint. 
    
    
     DESCRIPTION OF THE INVENTION 
     This invention is an applicator tool or tape gun  20  for continuously coating drywall or wallboard joint tape  21  with joint compound  22 , sometimes referred to as mastic or mud, and continuously applying the mud coated tape  21  to a joint  24  between two drywall panels  25 . The tool contains both a supply of tape  21  conveniently provided on a roll or spool  26  supported on the tool, and a supply of joint compound or mud  22  in a chamber  28  defined in a box or housing  29  and through which tape  21  from the roll  26  is fed for the application of mud thereto and the subsequent application of the coated tape to a drywall joint  24 . 
     The box for containing the joint compound  22  for application to the tape  21  is formed by a rear or back panel  30 , a top panel or wall  31 , a bottom panel or wall  32 , a right side or end wall or panel  33 , a sloping left side or end wall or panel  34 , and a front panel or cover  35 . The cover  35  is hinged or swingably mounted by a hinge  36  mounted along one edge of the cover  35  to a front panel  37  secured to the right side or end wall  33  and extending between the top wall  31  and bottom wall  32  of the housing  29 . The cover  35  is releaseably secured to the left side wall  33  by a toggle or pull latch  38 . The box  29  defines the interior chamber  28  for containing joint compound or mud  22  and including a tape entrance slot  39  through which joint tape  21  passes from the roll  26  into the chamber  28  for the application of mud  22  thereto, and a tape exit slot  40  through which coated tape  21  extends for application to a drywall joint  24 . 
     A back panel extension  41  and a hinged panel  42  spaced apart and extending from the right side of the box support a shaft  44  therebetween, which shaft  44  in turn supports a roll or spool  26  of tape  21 . The hinged panel  42  is supported by a hinge  45  at one edge to the box  29 , and is releasably secured by a latch  46  at its other end to an end wall  48  extending forwardly from the back panel extension  41  to facilitate loading of the spool  26  of tape  21 . 
     The box door or cover  35  includes side flanges or lips  49  extending rearwardly from the cover panel  35  for overlapping the side and end walls of the box to provide a seal to prevent leakage of joint compound from the chamber. Sealing strips  50  of rubber, felt or the like may be included between the side flanges  49  and the box walls. 
     The interior chamber  28  defined in the box  29  is defined by a bottom wall  51 , a sloping front or left side wall  52 , a curved upper and right side wall  54 , the box back panel  30  and the cover panel or door  35 . The sloping front wall and upper and right side wall together form an upper arcuate wall. Inserts  55 ,  56  having curved lower walls  57 ,  58 , may be placed in the upper left and right corners  59 ,  60  respectively of the box  29  in order to define the upper curved wall  54  of the chamber  28 . 
     In order to initially load the interior chamber  28  with tape  21  and joint compound or mud  22 , the door panel  35  is opened and the tape  21  is manually pulled from the spool  26  and inserted through the entrance slot  39  and exit slot  40 . The tape  21  is then raised or lifted upwardly against the upper curved surface or wall  54  of the chamber  28 , and joint compound  22  is manually filled into the portion of the chamber space defined below the tape  21  and above the bottom wall  51  of the chamber  28 . The door panel or cover  36  is closed and latched, and the tool is used to apply mud coated tape to a drywall joint  24  in the conventional manner by pulling the coated tape from the exit slot of the tool. 
     When the initial supply of mud  22  in the tool is exhausted, in accordance with the present invention the supply is replenished quickly and easily without opening the door panel or cover  35 . To this end, in accordance with the present invention, the portion of the tape remaining in the chamber is lifted and positioned against the upper curved surface  54  and the front surface  52  of the chamber by a lifter mechanism  61 , and joint compound  22  is supplied to the chamber below the tape  21  from a container or reservoir thereof (not shown). 
     The tape lifter mechanism  61  is formed by a lower elongated spring steel leaf  62  and an upper superimposed elongated spring plastic leaf  64 , both secured at corresponding ends to a shaft  65  which extends between the box front and rear panels adjacent the entrance slot and is journaled on the panels for rotation by an operating handle or crank  66  exterior of the box and operatively connected thereto. At its end opposite from the shaft connection, each leaf spring is provided with a transverse cylindrical knob, nose or bobbin  68 ,  69  respectively for engaging and lifting the tape. 
     The lower lifter spring leaf  62  is formed of stiffly flexible steel or clock spring material. The upper lifter spring leaf  64  is formed of stiffly flexible plastic material and defines a pair of parallel longitudinal slots  70  therein that assist in preventing the wet tape from sticking to leaf  64 . 
     The leaves are lifted to lift the tape in the chamber by swinging the handle in a clockwise direction, and retracted away from the tape by swinging the handle in the opposite direction. For engaging and holding the mud coated joint tape in the lifted position against the sloping front chamber wall  52  and curved upper chamber wall  54  for the replenishment of mud into the chamber after the lifter mechanism  61  is retracted, the upper front sloping wall  52  of the chamber is provided with an abrasive strip  71  which engages and grips the lifted tape  21 . To this end, the lifter leaves  62 ,  64  lift and press the tape against the upper sloping chamber wall  52  so that the tape is retained against the wall. The tape is held in contact with the upper arcuate top wall surface  54  by the mud with which it is coated. The steel spring leaf  62  when rotated by the handle initially engages the tape and presses it against the chamber wall with sufficient force to cause the tape to stick to the abrasive strip or surface  71  on the wall  52 . As the tape is lifted, the upper plastic leaf  64  lifts and presses the tape against the upper portion of the arcuate chamber wall  54  where it sticks until pulled free. The plastic leaf  64  is sufficiently flexible so that it gently lifts but does not tear the wet tape. The cylindrical nose  68 ,  69  on each leaf rides against the tape and further aids in preventing tearing of the wet tape  21 . 
     A carrying handle  72  including a handle grip  73  secured to a handle bracket  74  is mounted on the top of the box. A side handle  75  formed by a flexible fabric strap  76  is secured at to the back side wall of the box. The latter handle is adjustable by an adjustment clamp  78  including a bracket  79 , clamping plate  80  bolts  81  and wing nuts  82  securing the bracket  79  to the clamping plate  80 . 
     An adjustable bracket  83  forming a dam plate  84  and cutter blade  85  is provided adjacent the exit slot  40  at the front of the tool. The bracket  83  is adjustably secured to the sloping front or left wall  34  of the tool by appropriate bolts  86  and wing nuts  88  and may be adjusted upwardly or downwardly to vary the width of the exit slot  40  and thereby control the amount of mud applied to the tape  21 . The cutter blade  85  includes a sharp front edge  89  for cutting or tearing the tape  21  and appropriate finger slots  90 ,  91  for use by the tape installer for gripping the tape or pulling the tape manually through the chamber. 
     When periodically loading the chamber  28  with joint compound  22 , the tape  21  extending through the exit slot  40  is gripped by the user through the central finger slot  90  in the cutter blade  85  to prevent withdrawal of the tape back into the chamber as it is lifted. The handle  66  is then rotated to cause the lifter leaves  62 ,  64  to lift the tape  21  above and away from the bottom wall  51  of the chamber  28  and into contact with the front sloping wall  52  and upper curved wall  54  of the chamber  28 . The handle is then swung in the opposite direction to place the leaves  62 ,  64  against the bottom wall  51  of the chamber. At this point, the replenishment supply of mud is pumped into the chamber  28  through a valved port fitting  92  connected by a quick-connect connector fitting  95  to the mud reservoir (not shown). The port  92  is located between the lifter leaves  62 ,  64  and the raised tape. When the chamber  28  is full, as observed through a window  94  in the back wall panel  30  of the box  29 , supply of the mud to the chamber is stopped and the gun is disconnected from the supply reservoir. The fitting desirably includes an interior anti-backflow valve to prevent joint compound from leaking through the filling port when the tool is in use. Alternatively, after lifting the tape, joint compound can be supplied to the chamber  28  by opening the cover  35  and manually filling the chamber with compound. 
     When loading the tool with tape and joint compound, tape  21  is fed from the roll or spool  26  thereof through the entrance slot  39  and under a tape guide  96  defining the upper edge of the entrance slot  39 . To facilitate feeding of the tape  21  into the chamber  28 , an adjustable width tape entrance throat or slot  39  is provided by mounting the entrance tape guide cylinder or bobbin  96  on a plate  98  which is adjustably secured to the end wall  33  of the housing by releasable fasteners such as bolts  99  and wing nuts  100  or their equivalents. By loosening the wing nuts  100 , the cylinder  96  can be moved toward or away from the base or bottom wall or panel  32  of the housing  29  to reduce or enlarge the entrance slot  39 . 
     From the entrance tape guide cylinder  96 , the tape is fed over an idler cylinder or guide  101  into the chamber  28  and out through the exit slot  40 . The idler cylinder  101  is supported on an arcuate, stiffly flexible, panel  102  carrying the idler on one edge and secured adjacent its other edge to the bottom panel  32  of the housing  29 . 
     The action of the tape lifter  61  and lifter leaves  62 ,  64  is illustrated in FIGS. 14A-H, which figures show the sequence of movement and positions of the lifter leaves  62 ,  64  as the handle  66  is swung clockwise to lift the tape  21  and counter-clockwise to lower the lifter leaves  62 ,  64 , leaving the tape  21  in raised position and the chamber  28  ready to receive a supply of joint compound. 
     As shown schematically in FIG. 14A, the lifter springs  62 ,  64  initially lie adjacent the bottom panel  32  of the housing  29  with the plastic spring leaf  64  on top of the steel spring leaf  62  and the cylinder or bobbin  69  of the upper plastic leaf  64  lying behind the cylinder or bobbin  68  of the lower leaf  62 . As the handle  66  is swung further forward or clockwise as shown in FIG. 14B, The wet tape is lifted away from the bottom panel  32 . The nose  68  of the lower lifter leaf  62  presses the tape against the abrasive surface  71  of the sloping wall  52 , while the nose  69  of the upper leaf  64  lifts the tape  21 . 
     Further rotation of the handle  66  as shown in FIG. 14C raises the leaves  62 ,  64  with the nose  68  of the lower leaf sliding upon and along the tape  21  to press the tape against the sloping abrasive surface and causing the lower leaf to bow slightly. The nose of the upper leaf  64  further lifts the tape away from the lower leaf and positions it against the upper curved surface  54 . 
     As the lifter is further raised by rotating the handle, as shown in FIG. 14D, the nose  68  of the lower leaf  62  holds the tape against the abrasive front sloping surface  71  while the upper leaf bows to engage and press the wet tape  21  against the upper curved surface  54 , to which it adheres because of the mud with which is coated. At this point, as shown in FIG. 14D, the tape is fully lifted. It should be noted that the upper leaf  64  bows and presses the tape along its length against the upper curved surface. 
     With the tape lying against the abrasive surface and upper curved surface, the direction of movement of the handle  66  is reversed and the handle swung in a counterclockwise direction. As shown in FIG. 15A, the leaves  62 ,  64  drop away from the tape  21  which adheres to the upper curved surface  54 . The slots in the upper leaf help prevent the leaf from pulling the tape away from the curved surface. Counterclockwise rotation of the handle  66  positions the leaves  62 ,  64  together in their original position adjacent the lower housing wall  32 , leaving the tape stuck to the sloping surface and upper curved surface of the chamber. At this point joint compound can be introduced into the chamber as shown in FIG. 15B between the lower wall  32  and lifter  61  at the bottom, and the tape  21  at the top of the chamber. 
     As the drywall tape installer applies tape and joint compound  37  to a drywall joint  43 , the tape is continuously coated with the joint compound  27  as shown in FIG.  15 C. When the joint compound in the compound chamber has been substantially depleted, as shown in FIG. 15D, it is a simple matter for the user to swing the handle to lift the tape, then swing the handle back to lower the tape lifter to a position against the bottom wall of the chamber, connect the chamber input port to a mud supply through a quick connect connector, or open the front cover, and refill the chamber with joint compound. Taping of the wall joints is continued and this process is repeated until the drywall application is complete. With the taping tool embodying the present invention, the burdensome task of loading the tool with joint compound is substantially relieved, the speed of the taping work is increased, waste of joint compound is reduced, tearing or jamming of the tape is avoided, and physical contact of the user with the compound reduced thereby leading to cleanliness of the work area and less need for clean-up. 
     While a certain illustrative embodiment of the present invention has been shown in the drawings and described above in detail, it should be understood that there is no intention to limit the invention to the specific form disclosed. On the contrary the intention is to cover modifications, alternative constructions, equivalents, and uses falling within the spirit and scope of the invention as expressed in the appended claims.

Summary:
A tape and joint compound dispenser is formed by a housing defining an interior chamber for receiving joint compound and joint tape. A valved port in the housing opens into the chamber for supplying joint compound. A tape lifter in the chamber enables the user to lift the tape in the chamber to facilitate supplying joint compound to the chamber through the port and below the tape.