Apparatus for dispensing beaded adhesives

Abstract

A method for adhesively joining two members includes the steps of mixing non-compressible beads with an adhesive, applying the resulting mixture to one of the members and hemming one member over the other in overlapping relationship. Apparatus for performing this method includes a container for containing a mixture of an adhesive and a plurality of non-compressible beads, an applicator for applying the mixture to one of the members, and hemming means for hemming one member over the other in overlapping relationship. A metering device for dispensing adhesive fluid is constructed with a dispensing rod having a cooling means for facilitating operation of the metering device. The present invention finds particular utility in bonding together the inner and outer panels of an automotive door assembly.

What is claimed is:  
     
         1 . An adhesive application gun for dispensing an adhesive mixture having non-compressible beads therein comprising: 
 a housing defining a first chamber and a second chamber;    a elongated tube having an inlet in communication with said first and second chambers, an outlet and a mixing element disposed in said elongated tube between said inlet and said outlet to provide a tortuous mixing path therein;    a first valve operable to regulate flow of a first adhesive mixture including non-compressible beads and a first adhesive component through said first chamber and into said elongated tube; and    a second valve operable to regulate flow of a second adhesive component through said second chamber and into said elongated tube;    wherein said tortuous mixing path is operable to thoroughly mix said first adhesive mixture and said second adhesive component.    
     
     
         2 . The adhesive application gun of  claim 1  wherein said mixing element comprises a helical mixing element disposed in said elongated tube such that said tortuous mixing path includes a first side and a second side.  
     
     
         3 . The adhesive application gun of  claim 2  wherein said mixing element further comprises a plurality of helical mixing elements arranged in a stacked relationship in said elongated tube.  
     
     
         4 . The adhesive application gun of  claim 3  wherein said plurality of helical mixing elements are misaligned with respect an adjacent helical mixing element.  
     
     
         5 . The adhesive application gun of  claim 3  wherein said elongated tube is releasably secured to said housing to facilitate flushing thereof.  
     
     
         6 . The adhesive application gun of  claim 1  wherein said first valve comprises: 
 a first valve seat having a first valve orifice formed therethrough; and  
 a first valve element having a first valve plug slidably positionable with respect to said first valve seat to regulate flow of said first adhesive mixture through said first valve orifice.  
 
     
     
         7 . The adhesive application gun of  claim 6  wherein a surface of said first valve plug is at least partially spherical.  
     
     
         8 . The adhesive application gun of  claim 6  wherein said first valve element further comprises a first piston supported in said housing for sliding movement relative to said first valve seat and a first valve shaft interconnecting said first piston and said first valve plug.  
     
     
         9 . The adhesive application gun of  claim 8  wherein said first piston is disposed within a first valve chamber formed in said housing adjacent said first chamber.  
     
     
         10 . The adhesive application gun of  claim 6  wherein said second valve comprises: 
 a second valve seat having a second orifice formed therethrough; and  
 a second valve element having a second valve plug slidably positioned. with respect to said second valve seat to regulate flow of said second adhesive component through said second valve orifice.  
 
     
     
         11 . The adhesive application gun of  claim 10  wherein a surface of said second valve plug is at least partially spherical.  
     
     
         12 . The adhesive application gun of  claim 10  wherein said second valve element further comprises a second piston supported in said housing for sliding movement relative to said second valve seat and a second valve shaft interconnecting said second piston and said second valve plug.  
     
     
         13 . The adhesive application gun of  claim 12  wherein said second piston is disposed within a second valve chamber formed in said housing adjacent said second chamber.  
     
     
         14 . The adhesive application gun of  claim 1 , said housing further comprising an interior volume defined by a side wall, a rear panel, and a nozzle portion, and a partition dividing said interior volume into said first and second chambers, said elongated tube extending from said nozzle portion.  
     
     
         15 . An apparatus for dispensing an adhesive mixture with non-compressible beads therein comprising: 
 a first pump operable to pump a first adhesive mixture including non-compressible beads and a first adhesive component;    a second pump operable to pump a second adhesive component;    an application gun having a first chamber in communication with said first pump, a second chamber in communication with said second pump, and an elongated tube having an inlet in communication with said first and second chambers, an outlet and a mixing element disposed in said elongated tube between said inlet and said outlet to provide a tortuous mixing path for thoroughly mix said first adhesive mixture and said second adhesive component, wherein said tortuous mixing path is operable to thoroughly mix said first adhesive mixture and said second adhesive component.    
     
     
         16 . The apparatus of  claim 15  wherein said mixing element comprises a helical mixing element disposed in said elongated tube such that said tortuous mixing path includes a first side and a second side.  
     
     
         17 . The apparatus of  claim 16  wherein said mixing element further. comprises a plurality of helical mixing elements arranged in a stacked relationship in said elongated tube.  
     
     
         18 . The apparatus of  claim 17  wherein said plurality of helical mixing. elements are misaligned with respect an adjacent helical mixing element.  
     
     
         19 . The apparatus of  claim 17  wherein said elongated tube is releasably secured to said housing to facilitate flushing thereof.  
     
     
         20 . The apparatus of  claim 15  wherein said first valve comprises: 
 a first valve seat having a first valve orifice formed therethrough; and  
 a first valve element having a first valve plug slidably positioned with respect to said first valve seat to regulate flow of said first adhesive mixture through said first valve orifice.  
 
     
     
         21 . The apparatus of  claim 20  wherein a surface of said first valve plug is at least partially spherical.  
     
     
         22 . The apparatus of  claim 20  wherein said first valve element further comprises a first piston supported in said housing for sliding movement relative to said first valve seat and a first valve shaft interconnecting said first piston and said first valve plug.  
     
     
         23 . The apparatus of  claim 22  wherein said first piston is disposed within a first valve chamber formed in said housing adjacent said first chamber.  
     
     
         24 . The apparatus of  claim 20  wherein said second valve comprises: 
 a second valve seat having a second orifice formed therethrough; and  
 a second valve element having a second valve plug slidably positioned with respect to said second valve seat to regulate flow of said second adhesive component through said second valve orifice.  
 
     
     
         25 . The apparatus of  claim 24  wherein a surface of said second valve plug is at least partially spherical.  
     
     
         26 . The apparatus of  claim 24  wherein said second valve element further comprises a second piston supported in said housing for sliding movement relative to said second valve seat and a second valve shaft interconnecting said second piston and said second valve plug.  
     
     
         27 . The apparatus of  claim 26  wherein said second piston is disposed within a second valve chamber formed in said housing adjacent said second chamber.  
     
     
         28 . The apparatus of  claim 15  further comprising a first metering device having a first chamber in communication with said first pump, a first inlet valve regulating communication from said first pump to said first chamber, and a first discharge valve regulating communication from said first chamber through a first outlet.  
     
     
         29 . The apparatus of  claim 28  further comprising a first metering device having a second chamber in communication with said second pump, a second inlet valve regulating communication from said second pump to said second chamber, and a second discharge valve regulating communication from said second chamber through a second outlet.