Patent ID: 7237727
Filing Date: 2007-07-03
Classification: B05B

Abstract:
1. A paint spray gun comprising: a gun body having a handle portion, a head portion connected to said handle portion, and a nozzle mounted on said head portion, said nozzle being formed with a nozzle orifice, said gun body being formed with a material passageway that is in fluid communication with said nozzle orifice and that provides a path for flow of paint material to said nozzle orifice, said nozzle being further formed with a first air passageway that is fluidly isolated from said nozzle orifice, said gun body being further formed with a second air passageway that is in fluid communication with said first air passageway and that provides a path for flow of pressurized air from a compressed air source to said first air passageway; an operating unit mounted on said gun body and including a material flow controlling valve for controlling the flow of the paint material through said nozzle orifice, an air flow controlling valve for controlling the flow of the pressurized air through said second air passageway, and a trigger coupled operably to and controlling opening and closing actions of said material flow controlling valve and said air flow controlling valve; and a spray cap including a cap body disposed in front of said nozzle and formed with a central spray hole that has a hole axis extending in a longitudinal direction and that is registered and in fluid communication with said nozzle orifice, at least a pair of mist forming holes that are opposite to each other in a first diametrical direction relative to the hole axis and that are disposed on opposite sides of said central spray hole, a pair of horn projections that extend from said cap body in the longitudinal direction away from said nozzle and that are disposed adjacent to said mist forming holes, each of said horn projections having a root end that is connected to said cap body, a tip end that is opposite to said root end in the longitudinal direction, and a lateral side that extends between said root and tip ends and that faces toward said central spray hole, each of said horn projections being formed with a third air passageway, said third air passageway terminating in at least a first outlet opening that is formed in said lateral side, and a second outlet opening that is formed in said tip end, a pair of mist controlling holes that are opposite to each other in a second diametrical direction relative to the hole axis and that are disposed on opposite sides of said central spray hole, the second diametrical direction forming an angle with the first diametrical direction, wherein each of said mist controlling holes has a central axis that intersects the hole axis of said central spray hole at an upstream side of said cap body, and a pair of orifices that are opposite to each other in the second diametrical direction relative to the hole axis and that are disposed on opposite sides of said central spray hole, each of said orifices being disposed between said central spray hole and a respective one of said mist controlling holes, said mist forming holes, said third air passageways in said horn projections, said mist controlling holes, and said orifices being in fluid communication with said first air passageway, wherein the paint material that flows out of said central spray hole is atomized by the pressurized air that flows out of said first outlet openings in said horn projections and said mist forming holes, and wherein the pressurized air that flows out of said second outlet openings in said horn projections and said mist controlling holes forms an air barrier around the atomized paint material to control dimensions of an area to be painted by the atomized paint material.