Abstract:
A portable gun provides for the dispensing of flowable adhesives. The gun accommodates a flowable adhesive contained in a collapsible container which adhesive is dispensed through an extending dispensing nozzle.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a portable gun for dispensing flowable adhesive contained in a collapsible container. More particularly, the present invention relates to a pneumatically operated dispensing gun having an elongate barrel which accommodates an adhesive-filled collapsible tube for dispensing adhesive. 
     BACKGROUND OF THE INVENTION 
     Accurate application of various viscous materials such as adhesives and the like is typically achieved by the use of dispensing guns, most notably, caulking guns. A conventional caulking gun supports adhesive material in a tube or other container and is designed, by operation of the gun, to dispense or expel the adhesive through a nozzle at one end of the container. Many caulking guns of this type are manually operated in that repetitive actuation of a trigger moves a plunger-like piston into dispensing contact with the adhesive containing container. Continuous movement of the piston by hand operation provides for a continuous dispensing of the adhesive. Other guns of this type may be power driven, for example, by pneumatic operation. In these situations, air pressure is used to compress or collapse an adhesive containing tube to dispense the adhesive through the nozzle. 
     One specific use of such dispensing guns, by way of example, is to apply adhesives to floor joists where subflooring may be applied over the adhesively coated joists so as to fasten the subfloor to the joists. As may be appreciated, the gun must be capable of accurately dispensing the adhesive on the joist so that the proper amount of adhesive is applied with little waste. Many of the conventional dispensing guns, therefore, require the installer to operate the gun in close proximity to the floor joist. This would require the installer to have to kneel or bend to be close to the floor to accurately place the adhesive on the joists. Still further, the size of the guns requires frequent refilling which becomes time consuming and costly for installation. 
     SUMMARY OF THE INVENTION 
     The present invention provides a gun for dispensing a flowable adhesive contained in a collapsible tube which may be dispensed through an extending dispensing nozzle. The gun includes an elongate hollow barrel for accommodating the tube. The barrel has a closed first end and an open second end. The closed first end has an aperture therethrough for passage of the extending dispensing nozzle. A handle is attachable to the open end of the barrel for closing the open end. The handle has a connection port in communication with the hollow barrel for attachment to a source of pneumatic pressure. The handle further includes a trigger operably connected to a connection port to allow controlled flow of air pressure into the barrel which collapses the tube causing dispensing of the flowable adhesive therethrough. 
     The present invention provides an assembly which includes in combination an elongate adhesive dispensing gun, an elongate collapsible adhesive-containing tube having a dispensing nozzle at one end and guide attached to the nozzle. 
     In addition, a kit of parts is provided wherein the kit includes a plurality of different length barrels attachable to a handle at one end of the barrel. A cover encloses the other end of said barrel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a dispensing gun of the present invention. 
         FIG. 2  is a plan view of the dispensing gun of  FIG. 1 , partially in section, showing the internal passage of the barrel. 
         FIG. 3  is an enlarged perspective showing of a rear portion of the dispensing gun of  FIG. 1  shown in the open condition. 
         FIG. 4  shows the dispending gun of  FIG. 1  and alternative length barrels used in combination therewith. 
         FIGS. 5 and 6  show the front end of an alternative embodiment of a dispensing gun of the present invention, respectively, in an exploded and assembled condition. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a dispensing gun which pneumatically dispenses adhesive contained within a collapsible container such as an elongate collapsible tube having a tapered dispensing nozzle at one end. While the invention is described with respect to an elongate bag-like tube, other configurations are within the contemplation of the present invention. 
     Referring now to  FIGS. 1 and 2 , the dispensing gun  10  of the present invention is shown. Dispensing gun  10  includes an elongate hollow barrel  12  which is preferably cylindrical in configuration. The barrel includes a first open end  14  and an opposed second open end  16 . The barrel further includes a generally hollow cylindrical passageway  18  extending between the ends  14  and  16 . 
     Attached to the first end  14  of barrel  12  is a cover  20  which closes the first end. The cover may be affixed to the first end of barrel  14  by well known attachment methods such as press fitting the cover  20  onto the end  14 . The cover is designed to attach to the first end of the barrel in a sealed air-tight fashion. Various sealed attachment techniques, including adhesive attachment, are within the contemplation of the present invention. As will be described in further detail hereinbelow, the cover  20  is configured to accommodate in sealed relationship the front end of a dispensing tube. In addition, the cover includes a central aperture  22  at a distal end thereof for accommodating the extending nozzle of the tube. 
     The second end  16  of barrel  12  supports thereon a handle  30 . Handle  30  is generally in the configuration of a pistol grip. However, other configurations are within the contemplation of the present invention. 
     Referring additionally to  FIG. 3 , the pistol grip handle  30  is a two component device including a cap portion  32  and a grip portion  34 . The cap portion  30  is generally an annular member into which is fitted onto the second end  16  of barrel  12 . As with the first end  14  of barrel  12 , the second end  16  can be press fit or otherwise secured to the cap portion  32 . The cap portion is designed to attach to the second end of the barrel in an air-tight fashion. An adhesive may be used to effect such sealing. The cap portion  32  includes an elastomeric sealing member  36  which preferably is in the form of an O-ring. The sealing member  36  provides for sealed engagement of the grip portion  34  of handle  30  with the cap portion  32 . In that regard, the grip portion  34  is hingedly attached to cap portion  32  by a pivotal hinge  40 . Hinge  40  permits movement of the grip portion  34  with respect to the cap  32  between an open condition shown in  FIG. 3  and a closed condition shown in  FIGS. 1 and 2 . A releasable latch mechanism  42 , including a latch  44  and a catch  46 , provides for secure connection of the grip portion and the cap in the closed position. 
     Grip portion  34  further includes an operable trigger  48  which may be manually depressed by the user. The trigger is in operable connection with a pneumatic air connection port  50 . Connection port  50  includes a mating connector  52  which can be used to snap fit to a pneumatic line  54  which extends to a source of pressurized air  56 . The connection port  50  is in fluid communication with the grip portion  34  and cap portion  32  of handle  30  so as to establish fluid communication between the connection port and the interior  18  of barrel  12 . The trigger may be depressed to open and close the fluid communication path between the connection port  50  and the interior  18  of barrel  12  to selectively apply pressurized air to the barrel passageway. The pressurized air source  56  may be any conventional pneumatic source and may be either fixed such as in the use of an air compressor which is attached with a pneumatic hose or may be portable to move along with the gun  10 . 
     Turning again to  FIGS. 1 and 2 , an adhesive tube  60  is shown. Adhesive tube  60  is an elongate member having a closed rear end  62  and an opposite tapered forward end  64  having dispensing nozzle  66  extending therefrom. Dispensing nozzle  66  is a conventional tapered dispensing nozzle which permits the nozzle to be severed at various lengths therealong to increase the dispensing opening. A cap  65 , shown in  FIG. 1 , may cover the cut tip of the dispensing nozzle when not in use. The tube  60  is generally a bag-like collapsible member which may be collapsed upon application of pneumatic pressure to dispense the adhesive contents contained therein through the dispensing nozzle  66 . 
     Operation of the gun  10  of the present invention is shown with respect to  FIG. 2 . The collapsible adhesive tube  60  is loaded into the barrel  12  with the handle  30  being in the open position as shown in  FIG. 3 . The adhesive tube  60  is inserted into the passage  18  of the barrel until the nozzle extends through the opening in cover  20 . The front end of the tube  60  seats with the cover  20  establishing an air-tight seal. The grip portion  34  is then pivotally closed to cap portion  32  and latchably secured employing latch  42 . The gun  10  is connected to a source of compressed air  56  at connector  52 . Trigger  48  is depressed permitting flow of pressurized air through connection port  50  and into passage  18  of barrel  12 . Continuous pneumatic pressure applied to tube  60  results in collapsing of the tube and the dispensing of the adhesive contents through nozzle  66 . Release of trigger  48  stops the flow of air through connection port  50  and thereby stops the dispensing of adhesive through nozzle  66 . Thus, the present invention provides a pneumatically operated gun for dispensing adhesive from a collapsible tube. The amount of adhesive disposed can be controlled by controlling the air pressure as well as by the cutting of the nozzle. 
     Referring now to  FIG. 4 , a further feature of the present invention is shown. As may be appreciated, the gun of the present invention may be used to dispense adhesive to various surfaces. Each of these surfaces may be at various distances from the installer who is applying the adhesive. For example, the installer may wish to apply adhesive to a relatively close surface, or in other situations, the surface to which the adhesive to be may be applied may be a distance from the installer. In these situations, the present invention provides a gun which allows for the selective attachment of different length barrels thereto. 
     As shown in  FIG. 4 , an assembly  11  may be provided where a plurality of different length barrels  12   a ,  12   b  and  12   c  may be employed. The installer would have the option to selectively use the desired length barrel by attaching the selected barrel to the handle  30  and cover  20 . For example, where the installer wishes to apply adhesive to a surface in close proximity to the installer, a small length barrel  12   a  may be applied. In other situations, particularly in situations where the installer wishes to apply adhesive to floor joists for subsequent application of a subflooring, the installer may use the extended length barrel  12   c . In such an instance, the installer may operate the adhesive gun to apply adhesive directly on the floor joists without having to kneel or bend to be close to the application location. While three barrel lengths are shown in  FIG. 4 , it is of course within the contemplation of the present application that the gun assembly may be provided with barrels of other numbers and lengths. 
     The ability to change or select barrel lengths also provides the ability to accommodate different sizes of adhesive tubes. Use of larger volume adhesive tubes would result in the need to less frequently reload the gun with another tube. 
     Referring now to  FIGS. 5 and 6 , a further embodiment of the present invention is shown.  FIGS. 5 and 6  shows the front end of barrel  12 ′ where the cap portion of the barrel is integrally formed. Thus, the front end  14 ′ of barrel  12 ′ terminates in a closed front end  15 ′. The closed front end  15 ′ has a central aperture  22 ′ therethrough which is surrounded by an extended externally threaded collar  19 ′. The nozzle  66  of tube  60  extends through the opening  22 ′ and the threaded collar  19 ′. 
     The present invention further provides an alignment guide  70  which may be attached to the closed front end  15 ′ of barrel  10 ′. While the alignment guide is shown in use with the embodiments of  FIGS. 5 and 6 , it may be appreciated that the alignment guide may be used with the embodiments of  FIGS. 1-4 . 
     Alignment guide  70  includes a back wall  72 , a bottom wall  74  and a pair spaced apart guide walls  76  and  78 . The guide walls have outwardly directed distal feet  80  and  82 . The back wall  72  includes a generally U-shaped passageway  84  which is engageable about the extending threaded collar  16 ′. A threaded nut  85  is used to secure the alignment member  70  to the front end  15 ′ of barrel  12 ′. As shown in  FIG. 6 , the alignment guide  70  when attached to the front end  15 ′ of barrel  12 ′ extends approximately the length of the extending nozzle  66 . The outwardly directed feet  80  and  82  serve as positioners so that when the installer is applying adhesive to a surface such as a floor joist, the feet stabilize the nozzle during movement along the joist. This allows the installer to accurately place the proper amount of adhesive at the proper location on the joist. This results in accurate application and less waste. 
     While the invention has been described in relationship to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made without deviating from the fundamental nature and scope of the invention as defined in the appended claims.