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.
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.
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.
The present invention will be described and understood more readily when considered together with the accompanying drawings, in which:
Now turning to the drawings, there is shown in
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
Saddle seal 16, as clearly seen in
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.