Patent Publication Number: US-2006006251-A1

Title: Reversible spray tip unit

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to spray tips for use in spray guns used in the hydraulic atomization and spraying of liquids such as paint wherein the spray tip is reversible so that obstructions therein which clog the spray tip may be easily removed by the reversed flow of the high pressure liquid paint therethrough. More particularly, the present invention relates to a means for quickly and accurately assembling a disassembled reversible spray tip unit.  
     BACKGROUND OF THE INVENTION  
      The reversible spray tip unit or assembly with which the present invention is concerned is used in hydraulic or airless paint spraying and generally consists of a rotatable cylindrically shaped turret member arranged transverse to the flow of high pressure paint wherein a diametric fluid bore is provided for mounting of the spray tip or nozzle. A housing for the reversible spray tip unit is engaged by a securing nut which secures the spray tip unit to the discharge end of the spray gun. The spray tip unit housing permits the turret member to be axially rotated therein so as to present the spray tip forwardly for spray painting and rearwardly facing the discharge end of the spray gun so that clogs in the spray tip can be removed by the reversed flow of paint. A metallic, so-called saddle seal is received in an axial bore therefor in the spray tip unit housing so as to contact the face of the cylindrically shaped turret member at the diametric fluid bore therein. The sealing face of the saddle seal has a shape which is complementary to the cylindrical shape of the turret member and upstream therefrom an elastomeric sealing washer is arranged on the saddle seal which is compressed against the discharge end of the spray gun by the tightening of the securing nut. An axial fluid bore provided in the saddle seal delivers the high pressure fluid paint from the spray gun discharge to the fluid bore in the turret member. The spray tip unit housing is generally surrounded by a plastic tip guard having Y or V shaped forward extending ears. The turret member is provided with a T-shaped handle so that it may be easily rotated as required.  
      Because of the abrasive nature of all paints and coatings, wear necessarily occurs in the spray tip nozzle and the sealing faces of the turret member and saddle seal requiring replacement of the turret member containing a new spray tip nozzle and/or the saddle seal. In addition, it is frequently necessary during use of such reversible spray tip units to thoroughly clean the unit for one reason or another. As a result, such reversible spray tip units are frequently disassembled and reassembled by the painting operators during normal painting operations. This frequent disassembly and assembly of the reversible spray tip unit necessarily results in a significant amount of time being spent by the painting operator in not painting. Particularly time consuming during the assembly of the reversible spray tip unit is arranging the saddle seal in the saddle seal bore of the housing so that the cylindrically shaped sealing face thereof is properly aligned with the bore provided in the housing for the turret member. Since the saddle seal itself is generally cylindrically shaped as is the bore therefor in the housing, the proper orientation of the saddle seal within the bore so that the sealing face thereof aligns with the turret member bore is generally accomplished by trial and error. Thus, the operator must sight down the turret member bore during the insertion of the saddle seal and if the saddle seal is misaligned, a part of the edge of the sealing face will intrude into the bore and interfere with the insertion of the turret member. In that event, it is necessary for the operator to remove the saddle seal from the turret member housing and try again for proper alignment.  
     SUMMARY OF THE INVENTION  
      The primary object of the present invention is to provide a reversible spray tip unit for an airless spray gun having an axially rotatable cylindrically shaped turret member with the spray tip nozzle arranged in a diametric fluid bore therein, the turret member being disposed in a complementary shaped bore of the unit housing and arranged transverse to the flow of paint, and a saddle seal received axially in the housing and having a cylindrically shaped sealing face mating with the cylindrical shape of the turret member at the diametric fluid bore housing the spray tip nozzle, wherein upon assembly of the disassembled reversible spray tip unit, the saddle seal can be quickly inserted and precisely oriented to align the cylindrically shaped sealing face thereof with the cylindrically shaped bore in the housing for the turret member so that the turret member can be received in the housing bore therefor.  
      The above object is accomplished by providing the fluid bore of the saddle seal in the form of a keyway or key seat adapted to receive therein the key of an insertion/orientation tool. The insertion/orientation tool is provided for inserting the saddle seal into the saddle seal bore of the housing and because it is keyed to the fluid bore thereof, the saddle seal can be easily oriented within the saddle seal bore by the rotation of the insertion/orientation tool in the manner of a key which axially rotates the saddle seal within the bore therefor. Advantageously, the key of the insertion/orientation tool is formed as part of the turret member and preferably as one of the ends of the top cross member of the T-shaped handle and is arranged thereon so that when keyed to the fluid bore of the saddle seal the axial direction of the cylindrically shaped sealing face of the saddle seal is aligned with the axial direction of the turret member. Thus, upon insertion of the saddle seal into the saddle seal bore of the turret member housing, the alignment of the sealing face of the saddle seal with the turret member bore of the housing is easily accomplished by aligning the axial direction of the turret member connected to the T-shaped handle therefor parallel with the axial direction of the turret member bore of the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will be described and understood more readily when considered together with the accompanying drawings, in which:  
       FIG. 1  is a perspective rear view of a reversible spray tip unit embodying the present invention;  
       FIG. 2  is an exploded view of the reversible spray tip unit of  FIG. 1 ;  
       FIG. 3  is a side view of the reversible spray tip unit shown without the turret member;  
       FIG. 4  is a cross sectional view of the reversible spray tip unit shown in  FIG. 3  taken along the line  4 - 4  of  FIG. 3 ;  
       FIG. 5A  is a perspective view showing the insertion/orientation tool aligned with the saddle seal which in turn is aligned for insertion into the spray tip unit housing;  
       FIG. 5B  is a view similar to  FIG. 5A , showing the insertion/orientation tool cooperating with the saddle seal;  
       FIG. 5C  shows the insertion/orientation tool inserting the saddle seal into the spray tip unit housing;  
       FIG. 5D  is a perspective view showing the saddle seal seated in the spray tip unit housing; and  
       FIG. 6  is a side elevational view of a turret member incorporating another embodiment of insertion/orientation tool. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Now turning to the drawings, there is shown in  FIGS. 1 and 2 , a reversible spray tip unit, generally designated  10 , including a turret member  12 , a spray tip unit housing  14  and a saddle seal  16 . Turret member  12  includes a barrel shaped portion, designated  18 , to an end of which is attached a T-shaped handle  20 . Barrel portion  18  has a diametric through bore  22  formed therein at one end of which is housed the spray tip nozzle (not shown). As clearly seen in  FIG. 2 , the top cross member  24  of the T-shaped handle  20  is in alignment with bore  22  and advantageously, cross member  24  is provided with the general shape of an arrow wherein the point of the arrow indicates the exit direction of the spray tip nozzle. Thus, as seen in  FIG. 1 , the arrow shape of cross member  24  is pointed rearwardly indicating that the spray tip nozzle housed in turret member  12  is in reversed position facing the discharge end of a spray gun (not shown) to which reversible spray tip unit  10  is attached for clearing any clogs therein.  
      Spray tip unit housing  14  is provided with V or Y-shaped tip guard  26  and a securing nut  28  for securing the reversible spray tip unit  10  to the forward or discharge end of the spray gun. A cylindrically shaped transverse bore  30  is formed in housing  14 , as clearly seen in  FIG. 4 , to receive barrel portion  18  of turret member  12  therein. An axial through bore  32  is provided in housing  14  in alignment with the spray gun discharge and in alignment with fluid bore  22  of turret member  12  when barrel  18  thereof is seated in bore  30  of housing  14 .  
      Saddle seal  16 , as clearly seen in  FIG. 2 , is received in the upstream end of bore  32  of housing  14  and when properly seated therein its cylindrically shaped sealing face  34  aligns with bore  30  as seen in  FIG. 4 . Saddle seal  16  is provided at its upstream end in contact with the discharge end of the spray gun with a resilient sealing washer  36  and has an axial fluid bore  38  therein which aligns with fluid bore  22  of turret member  12  when the reversible spray tip unit  10  is fully assembled.  
       FIGS. 5A  to  5 D show in accordance with the present invention, how saddle seal  16  is inserted into bore  32  of housing  14  and oriented therein so that the cylindrically shaped sealing face  34  thereof can be easily and accurately aligned with bore  30  of housing  14  as shown in  FIG. 4 . Thus, as clearly seen, fluid bore  38  of saddle seal  16  is shaped as a keyway or key seat so as to be keyed to key  40  of an insertion/orientation tool  42  so that the orientation of saddle seal  16  within bore  32  of housing  14  can be easily adjusted by rotating or turning tool  42  which in turn rotates saddle seal  16 . The insertion/orientation tool  42  is advantageously formed as part of turret member  12  and preferably it is formed at one end of top cross member  24  of T-shaped handle  20 . Key  40  of insertion/orientation tool  42  is oriented so that when it engages with and is keyed to the keyway of fluid bore  38 , as clearly seen in  FIG. 5B , the axial direction of cylindrically shaped sealing face  34  of saddle seal  16  is parallel to the axial direction of barrel  18  of turret member  12 . Thus, as saddle seal  16  is inserted into bore  32  of housing  14 , as shown in  FIG. 5C , sealing face  34  can be aligned with bore  30  of housing  14  in one of two ways. The first is by visually sighting down bore  30  and axially adjusting the orientation of saddle seal  16  by turning turret member  12  in the direction of arrow A until sealing face  34  aligns with bore  30 . The second way for accurately aligning sealing face  34  of saddle seal  16  with bore  30  is by aligning barrel  18  of turret member  12  parallel to bore  30  prior to insertion of the saddle seal whereby the axial direction of cylindrically shaped sealing face  34  is parallel to the axial direction of bore  30  of housing  14  and then inserting the properly oriented saddle seal.  
       FIG. 6  shows another arrangement of the insertion/orientation tool whereby insertion/orientation tool  142  is arranged at an end of barrel shaped portion  18  of turret member  12  opposite T-shaped handle  20 . Thus, key  140  of insertion/orientation tool  142  is disposed axially at the end of barrel shaped portion  18 . In all other respects insertion/orientation tool  142  operates in the same manner as insertion/orientation tool  42 , described above.  
      While only a single embodiment of the present invention has been shown and described, it will be obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the present invention.