Low pressure polyurethane spraying assembly

A spray gun assembly for mixing and initiating the reaction of two liquid reactive polymeric materials and spraying the mixture onto a surface, said assembly comprising;

• a manifold having first and second pre-mixing chambers with an actuating valve disposed within each of said chambers;
• a first fluid port disposed within said first pre-mixing chamber for delivering a first material to said first pre-mixing chamber;
• a second fluid port disposed within said second pre-mixing chamber for delivering a second material to said second pre-mixing chamber;
• a mixing device mounted to said manifold;
• a spray tip mounted to said mixing device;
• an air cap mounted to a distal end of said spray tip and in fluid communication with said first and second pre-mixing chambers of said manifold;
• a main outlet port disposed within said air cap;
• atomizing outlet ports disposed within said air cap surrounding said main outlet port;
• a first air inlet port mounted in close proximity to said second fluid port within said second pre-mixing chamber for delivering a gaseous material to said second pre-mixing chamber, into said mixing device, through said air cap, and out said main outlet port;
• a second air inlet port mounted on said spray tip for delivering the gaseous material into said air cap and out said atomizing outlet ports;
• a cross-over air hose interconnecting said first air inlet port and said second air inlet port;
• and
• a first supply air hose for supplying the gaseous material;
• said assembly characterized by;
• a valve assembly interconnecting said first air inlet port, said first supply air hose, and said cross-over air hose for simultaneously supplying the gaseous material to said second pre-mixing chamber, said mixing device, said air cap, and said second air inlet port to simultaneously discharge the gaseous material out said main outlet port and said atomizing outlet ports for removing the first and second materials from said mixing device, said air cap, said main outlet port, and said atomizing outlet ports after spraying a mixture of the first and second materials onto a surface.

An assembly for mixing and initiating the reaction of two liquid reactive polymeric materials and spraying the mixture onto a surface, said assembly comprising;

• a first pump having multiple pumping chambers with a diaphragm in each chamber;
• an inlet port on said first pump for delivering a first material to said diaphragms;
• a first drive assembly for sequentially moving said diaphragms to continuously move the first material through said first pump;
• an outlet port on said first pump for discharging the first material under pressure;
• a first flow meter connected to said outlet port of said first pump for receiving the first material under pressure;
• a first feedback controller interconnecting said first flow meter and said first drive assembly for governing said first drive assembly in response to fluid flow through said first flow meter;
• a second pump having multiple pumping chambers with a diaphragm in each chamber;
• an inlet port on said second pump for delivering a second material to said diaphragms;
• a second drive assembly for sequentially moving said diaphragms to continuously move the second material through said second pump;
• an outlet port on said second pump for discharging the second material under pressure;
• a second flow meter connected to said outlet port of said second pump for receiving the second material under pressure;
• a second feedback controller interconnecting said second flow meter and said second drive assembly for governing said second drive assembly in response to fluid flow through said second flow meter;
• a spray gun having a manifold with first and second pre-mixing chambers;
• a first fluid port disposed within said first pre-mixing chamber for delivering the first material to said first pre-mixing chamber;
• a second fluid port disposed within said second pre-mixing chamber for delivering the second material to said second pre-mixing chamber;
• a first hose interconnecting said first flow meter and said first fluid port of said first pre-mixing chamber for conveying the first material from said first flow meter to said first pre-mixing chamber;
• a second hose interconnecting said second flow meter and said second fluid port of said second pre-mixing chamber for conveying the second material from said second flow meter to said second pre-mixing chamber;
• a mixing device mounted to said manifold;
• a spray tip mounted to said mixing device;
• an air cap mounted to a distal end of said spray tip and in fluid communication with said first and second pre-mixing chambers of said manifold for spraying a mixture of the first and second materials onto a surface;
• a main outlet port disposed within said air cap;
• atomizing outlet ports disposed within said air cap surrounding said main outlet port for atomizing the mixture of the first and second materials;
• a first air inlet port mounted in close proximity to said second fluid port within said second pre-mixing chamber for delivering a gaseous material to said second pre-mixing chamber, into said mixing device, through said air cap, and out said main outlet port;
• a second air inlet port mounted on said spray tip for delivering the gaseous material into said air cap and out said atomizing outlet ports;
• a cross-over air hose interconnecting said first air inlet port and said second air inlet port;
• a first supply air hose for supplying the gaseous material;
• and
• a valve assembly interconnecting said first air inlet port, said first supply air hose, and said cross-over air hose for simultaneously supplying the gaseous material to said second pre-mixing chamber, said mixing device, said air cap, and said second air inlet port to simultaneously discharge the gaseous material out said main outlet port and said atomizing outlet ports for removing the first and second materials from said spray gun after spraying the mixture of the first and second materials onto the surface.