Coating system

Claim 2

A coating system comprising: a spray gun body having a forward end provided with a passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a nozzle through which coating material is ejected from the forward end of the body, said nozzle having an internal orifice surface, a forward facing surface joining said internal orifice surface and a conical outer surface converging to join said forward facing surface, a conical forwardly converging surface in said forward end around said nozzle conical outer surface to form an annular converging orifice for ejecting air to atomize said ejected coating material, a passage in said forward end to provide air under pressure having an outlet connected to said annular converging orifice and having an intake, and a source of air connected to said intake and means for providing air in a sufficient quantity and under sufficient high pressure to eject a converging atomizing air stream through said annular converging orifice to an intersecting point where the converging air stream is transformed into a smaller diameter non-converging air stream combined with atomized coating material.

Claim 3

A coating system as specified in claim 1, wherein said forward facing surface is in a plane perpendicular to said internal orifice surface.

Claim 4

A coating system as specified in claim 1, wherein said forward facing surface is conical and diverges forwardly to form an obtuse angle with said internal orifice surface and an edge with said conical outer surface.

Claim 5

A coating system as specified in claim 1, wherein said forward facing surface is concave and forms an edge with said conical outer surface.

Claim 6

In combination with the coating system specified in claim 1: a pair of opposed orifices mounted in said body outwardly of said annular orifice through which air is ejected to convege at a point forward of said point where air from said annular orifice converges.

Claim 7

A coating system as specified in claim 5, wherein said forward facing surface is in a plane perpendicular to said internal orifice surface.

Claim 8

A coating system as specified in claim 5, wherein said forward facing surface is conical and diverges forwardly to form an obtuse angle with said internal orifice surface and an edge with said conical outer surface.

Claim 9

A spray gun as specified in claim 5, wherein said forward facing surface is concave and forms an edge with said conical outer surface.

Claim 10

A coating system in accordance with claim 1, wherein said nozzle is electrically conductive and a source of electrical potential is connected between said nozzle and work to be coated.

Claim 11

In combination with the coating system specified in claim 1, a container for holding conductive coating, a fluid conduit connecting said container and said intake to transport conductive coating material from said container to said spray gun body passage, a high voltage supply connected between conductive coating material in said container and work to be coated, and means applying an elEctrostatic field to the atomized coating material including said nozzle.

Claim 12

A coating system in accordance with claim 10, wherein said body forward end including said nozzle is electrically non-conducting.

Claim 13

In combination with the coating system specified in claim 1, a restriction in said passage providing a coating flow cross section area which is less than a minimum coating flow cross section area of said nozzle internal orifice.

Claim 14

A coating system as specified in claim 12, wherein said nozzle flow cross section area bears a ratio of approximately three to one to said restriction flow cross section area in said passage.

Claim 15

In combination with the coating system specified in claim 1, a needle valve movable longitudinally in said passage to seat against a valve seat adjacent said nozzle orifice having a cross sectional area sufficient to reduce the coating flow area around said needle valve to a cross sectional area less than a minimal cross sectional area of said internal orifice.

Claim 16

A coating system in accordance with claim 1, wherein at least a portion of said passage has a coating flow cross sectional area less than a minimal cross sectional flow area of said internal orifice.

Claim 17

The coating system specified in claim 1, wherein the velocity of said air being forced over said sharp edge exceeds the velocity of coating material being ejected from said orifice.

Claim 18

In combination with the coating system specified in claim 1, a container for holding coating material, a fluid conduit connecting said container and said intake to transport coating material from said container to said spray gun body passage, means applying an electrostatic field to the atomized coating material including an electrical conducting element extending forwardly of said body, and a high voltage supply connected between said electrical conducting element and work to be coated.

Claim 19

A coating system as specified in claim 17, wherein said body forward end is electrically non-conducting.

Claim 20

In combination with the coating system specified in claim 1, a container for holding coating material, a fluid conduit connecting said container and said intake to transport coating material from said container to said spray gun passage, means applying an electrostatic field to the atomized coating material including said nozzle, and a high voltage supply connected between said nozzle and work to be coated.

Claim 21

A coating system in accordance with claim 19, wherein said body forward end is electrically non-conducting except for said nozzle.

Claim 22

In combination with the coating system specified in claim 1, a valve moveable in said passage to seat against a valve seat.

Claim 23

A coating system comprising a spray gun body having a forward end provided with a nozzle having an orifice through which coating material is ejected at a velocity from the forward end of the body, wherein the improvement comprises an annular conical orifice surrounding and spaced from said nozzle orifice and means for ejecting air through said annular converging orifice at a higher velocity than said ejected coating material velocity to converge at a point forward of said nozzle and there form a non-converging stream of air and atomized coating material.

Claim 24

A coating system comprising a spray gun body having a forward end provided with a nozzle having an orifice through which coating material is ejected at a velocity from the forward end of the body, wherein the improvement comprises an annular conical orifice surrounding and spaced from said nozzle orifice and means for ejecting air through said annular converging orifice at a higher velocity than said ejected coating material velocity to converge at a point forward of said nozzle and there form a non-converging stream of air and atomized coating material.

Claim 25

A coating system as specified in claim 22, wherein said nozzle has a forward facing surface which lies in a plane perpendicular to the direction of coating fluid flow through said nozzle.

Claim 26

A coating system as specified in claim 22, wherein said nozzle has a conical forward facing surface that diverges forwardly.

Claim 27

A coating system as specified in claim 22, wherein said nozzle has a concave forward facing surface that terminates in a sharp annular edge.

Claim 28

In combination with the coating system specified in claim 22, a pair of opposed orifices mounted outwardly of said nozzle through which air is ejected to converge at a point forward of the point where air from said annular conical oRifice converges.

Claim 29

A coating system as specified in claim 26, wherein said nozzle has a forward facing surface lying in a plane perpendicular to the direction of coating fluid flow through said nozzle.

Claim 30

A coating system as specified in claim 26, wherein said nozzle has a conical facing surface that diverges forwardly to an annular edge.

Claim 31

A coating system as specified in claim 26, wherein said nozzle has a concave forward facing surface which terminates in an annular edge.

Claim 32

A coating system as specified in claim 22, wherein said nozzle is electrically conductive and a source of electrical potential is connected between said nozzle and work to be coated.

Claim 33

In combination with the coating system specified in claim 22, means for restricting an ejection flow of coating material through said nozzle to less than approximately 500 feet per minute.

Claim 34

In combination with the coating system specified in claim 22, a shield of electrical non-conductive material surrounding all electrical conducting portions of said body, means applying an electrostatic field to the material passing from the nozzle including an electrical conducting element extending through said shield at said nozzle, and a high voltage supply connected between said electrical conducting element and work to be coated.

Claim 35

In combination with the coating system specified in claim 22, a shield of electrical non-conductive material surrounding all electrical conducting portions of said body, means applying an electrostatic field to the material passing from the nozzle including said nozzle extending through said shield, and a high voltage supply connected between said nozzle extending through said shield and work to be coated.

Claim 36

A coating system as specified in claim 33, wherein said forward facing surface is conical and diverges forwardly to form an obtuse angle with said internal orifice surface and an edge with said conical outer surface.

Claim 37

A coating system as specified in claim 33, wherein said forward facing surface is concave and forms an edge with said conical outer surface.

Claim 38

A coating system comprising, a nozzle having an orifice and a forward facing surface extending outwardly from said orifice, means for forming coating material ejected from said orifice into a thin film spreading outwardly over said forwardly facing surface to an outer edge of said converging surface, and means for forcing air over said sharp edge to a point forward of said orifice to atomize said thin film of coating material and to transport the atomized coating material to said point.

Claim 39

A coating system comprising, a nozzle having an orifice and a forward facing surface extending outwardly from said orifice, means for forming coating material ejected from said orifice into a thin film spreading outwardly over said forwardly facing surface to an outer edge of said converging surface, and means for forcing air over said sharp edge to a point forward of said orifice to atomize said thin film of coating material and to transport the atomized coating material to said point.

Claim 40

In combination with the coating system specified in claim 36, means for spreading said atomized coating material into a fan-shaped pattern at a second point forward of said orifice and forward of said point.

Claim 41

A coating system as specified in claim 36, wherein said nozzle is electrically conductive and a source of electrical potential is connected between said nozzle and work to be coated.

Claim 42

In combination with the coating system specified in claim 36, means for restricting an ejection flow of coating material through said nozzle to less than approximately 500 feet per minute.

Claim 43

The coating system specified in claim 36, wherein the velocity of said ejected air exceeds the velocity of said ejected coating material.

Claim 44

A coating system comprising: a spray gun body having a forward end provided with a passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a nozzle through which coating material is ejected from the forward end of said body, said nozzle having an internal orifice surface, a forward facing surface joining said internal orifice surface and a conical outer surface converging to join said forward facing surface, a conical forwardly converging surface in said forward end around said nozzle conical outer surface to form an annular converGing orifice for ejecting air to atomize said ejected coating material, a passage in said forward end to provide air under pressure having an outlet connected to said annular converging orifice and having an intake connected to a source of air, a container for holding conductive coating, a fluid conduit connecting said container and said intake to transport conductive coating material from said container to said spray gun body passage, a high voltage supply connected between conductive coating material in said container and work to be coated, and means applying an electrostatic field to the atomized coating material including an electrical conducting element extending forwardly of said body and connected to said conducting coating material.

Claim 45

A coating system comprising: a spray gun body having a forward end provided with a passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a nozzle through which coating material is ejected from the forward end of said body, said nozzle having an internal orifice surface, a forward facing surface joining said internal orifice surface and a conical outer surface converging to join said forward facing surface, a conical forwardly converging surface in said forward end around said nozzle conical outer surface to form an annular converGing orifice for ejecting air to atomize said ejected coating material, a passage in said forward end to provide air under pressure having an outlet connected to said annular converging orifice and having an intake connected to a source of air, a container for holding conductive coating, a fluid conduit connecting said container and said intake to transport conductive coating material from said container to said spray gun body passage, a high voltage supply connected between conductive coating material in said container and work to be coated, and means applying an electrostatic field to the atomized coating material including an electrical conducting element extending forwardly of said body and connected to said conducting coating material.

Claim 46

A coating system in accordance with claim 41, wherein said body forward end including said nozzle is electrically non-conducting.

Claim 47

A coating system comprising a spray gun body having a forward end provided with a nozzle having an orifice through which coating material is ejected from the forward end of the body, wherein the improvement comprises: an annular conical orifice surrounding and spaced from said nozzle orifice through which air is ejected to converge at a point forward of said nozzle, a container for holding conductive coating, a fluid conduit connecting said container and said intake to transport condutive coating material from said container to said spray gun body passage, a high voltage supply connected between conductive coating material in said container and work to be coated, means applying an electrostatic field to the atomized coating material including an electrical conducting element extending forwardly of said body and connected to said conducting coating material, a shied of electrical non-conductive material surrounding all conducting portions of said body, and means applying an electrostatic field to the material passing from the nozzle including an electrical conducting element extending through said shield at said nozzle.

Claim 48

A coating system comprising a spray gun body having a forward end provided with a nozzle having an orifice through which coating material is ejected from the forward end of the body, wherein the improvement comprises: an annular conical orifice surrounding and spaced from said nozzle orifice through which air is ejected to converge at a point forward of said nozzle, a container for holding conductive coating, a fluid conduit connecting said container and said intake to transport condutive coating material from said container to said spray gun body passage, a high voltage supply connected between conductive coating material in said container and work to be coated, means applying an electrostatic field to the atomized coating material including an electrical conducting element extending forwardly of said body and connected to said conducting coating material, a shied of electrical non-conductive material surrounding all conducting portions of said body, and means applying an electrostatic field to the material passing from the nozzle including an electrical conducting element extending through said shield at said nozzle.

Claim 49

A coating system as specified in claim 43, wherein said forward facing surface is conical and diverges forwardly to form an obtuse angle with said internal orifice surface and an edge with said conical outer surface.

Claim 50

A coating system as specified in claim 43, wherein said forward facing surface is concave and forms an edge with said conical outer surface.

Claim 51

An electrostatic deposition coating system comprising: a spray gun body having a forward end provided with a passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a means through which coating material is ejected from the forward end of the body, a container for holding conductive coating, a flexible electrical non-conducting fluid conduit connecting said container and said intake to transport conductive coating material from said container to said spray gun body passage, a flexible shield of electrical conducting material surrounding said fluid conduit and connected to work to be coated, a high voltage supply connected between conductive coating material in said container and work to be coated, means applying an electrostatic field to the ejected coating material, and a flexible layer of electrical non-conductive material surrounding said flexible shield.

Claim 52

An electrostatic deposition coating system comprising: a spray gun body having a forward end provided with a passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a means through which coating material is ejected from the forward end of the body, a container for holding conductive coating, a flexible electrical non-conducting fluid conduit connecting said container and said intake to transport conductive coating material from said container to said spray gun body passage, a flexible shield of electrical conducting material surrounding said fluid conduit and connected to work to be coated, a high voltage supply connected between conductive coating material in said container and work to be coated, means applying an electrostatic field to the ejected coating material, and a flexible layer of electrical non-conductive material surrounding said flexible shield.

Claim 55

In combination with the method of coating specified in claim 47, the step of impinging opposing jets of air against said column of atomized material to form it into a fan-shaped pattern.

Claim 56

In combination with the method of coating specified in claim 47, the step of establishing an electrostatic field between said thin film, at an intersection of said thin film and said cone-shaped pattern of air, and work to be coated.

Claim 57

A coating system comprising: a spray gun having a forward end provided with a first passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a nozzle having an orifice through which coating material is ejected from the forward end of the body and with a second passage therein for connection to a source of pressurized air, an annular conical orifice surrounding and spaced from said nozzle orifice through which air is ejected to converge at a point forward of said nozzle and connected to said second passage, first means operatively connected to said first passage to control the velocity of coating material ejection through said orifice, second means operatively connected to said second passage to control the velocity of air ejection through said annular conical orifice, said first and second means being adjusted to eject air at a greater velocity than the ejection velocity of said coating material.

Claim 58

A coating system comprising: a spray gun having a forward end provided with a first passage therein having an intake for connection to a source of pressurized coating material and an outlet terminating in a nozzle having an orifice through which coating material is ejected from the forward end of the body and with a second passage therein for connection to a source of pressurized air, an annular conical orifice surrounding and spaced from said nozzle orifice through which air is ejected to converge at a point forward of said nozzle and connected to said second passage, first means operatively connected to said first passage to control the velocity of coating material ejection through said orifice, second means operatively connected to said second passage to control the velocity of air ejection through said annular conical orifice, said first and second means being adjusted to eject air at a greater velocity than the ejection velocity of said coating material.

Claim 59

A coating system in accordance with claim 50, wherein said first and second means are adjusted to provide a generally circular flow of air from said annular conical orifice toward the converging point, back toward the nozzle orifice and across a space between said nozzle orifice and said annular conical orifice.

Claim 60

A coating system in accordance with claim 50, wherein said first and second means are adjusted to force said coating material to flow from said nozzle orifice across a surface joining said orifices to said annular conical orifice where the ejected air impinges on said coating material to atomize it.