Patent Application
20150076250
The present invention relates generally to spray coating devices and, more particularly, to a spray gun incorporating a needle for applying multiple component material.
When multiple component coatings (e.g., paints) are used, they are typically mixed by a painter before the painter is ready to spray. Once the painter mixes the component materials together, a chemical reaction is started, and the painter has a limited time to apply the mixed material. Any left over material that the painter may have is then disposed of after the job. The cost of the wasted material may be significant. The spray apparatus must also be cleaned shortly after spraying to prevent the component materials from curing inside the spray apparatus, and also because the component materials may not be suitable for the next paint job because of the particular chemical reaction between the component materials.
Embodiments of a spray gun incorporating a needle for applying multiple component materials are provided. In accordance with certain embodiments, the spray gun includes a fluid delivery tip assembly comprising an inner passage, a hollow needle disposed within the inner passage of the fluid delivery tip assembly, wherein the hollow needle comprises at least two indentions along an outer circumferential surface of the hollow needle near an end of the hollow needle, a first passage configured to deliver a first spray fluid to a fluid tip exit of the fluid delivery tip assembly, wherein the first passage is defined by a volume between the fluid delivery tip assembly and the hollow needle, and a second passage through the hollow needle, wherein the second passage is configured to deliver a second spray fluid to the fluid tip exit of the fluid delivery tip assembly.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
The current automotive refinishing market is dominated by gravity feed spray guns that have a coating material reservoir mounted on top of the spray gun. When the trigger of the spray gun is pulled, an air valve opens allowing atomization air and pattern shaping air to flow to the air cap. As the trigger is pulled further back, the fluid needle unseats from the fluid tip allowing the material to flow from the reservoir to the fluid tip. The material then exits the fluid tip, where it is atomized and the atomized particles are shaped into a spray pattern. However, as described above, when using this type of spray gun, the user of the spray gun may only have a limited amount of time to apply the material after mixing. In addition, this type of spray gun may lead to waste of unused mixed material left over from the spraying. In addition, the spray gun must be cleaned to prevent curing inside the spray gun. One solution is to use a pressure feed, two-component mixing system, but this type of system may be prohibitively costly and may consist of a cumbersome three-hose bundle to deliver the compressed air, the first component material, and the second component material.
As discussed further below, various embodiments of a spray gun incorporating a needle for applying multiple component material are provided. In accordance with certain embodiments, a first component material may be delivered to the fluid tip of the spray gun from a first component material chamber defined between an inner passage of the fluid delivery tip assembly and the fluid needle of the spray gun. At the same time, a second component material may be delivered to the fluid tip of the spray gun through a hollow center of the fluid needle. As such, the first and second component materials may be mixed at or near the fluid tip of the spray gun, instead of being premixed prior to spraying. By not premixing the first and second component materials, several shortcomings of conventional spraying techniques may be addressed. For example, excess waste materials may be reduced because the first and second component materials are only mixed upon spraying. In addition, because mixing generally occurs in front of the fluid tip exit of the spray gun, cleaning of the spray gun may be required less frequently and may be less time consuming.
Turning now to the drawings,
The body 16 of the spray coating gun 12 includes a variety of controls and supply mechanisms for the spray tip assembly 14. As illustrated, the body 16 includes a first component material delivery assembly 34 having a first component material inlet passage 36 extending from a first component material inlet coupling 38 to a first component material chamber 40, which is generally defined as a passage between an inner wall of the fluid delivery tip assembly 18 and an outer surface of a multiple component delivery needle 42 of a fluid needle valve assembly 44. The first component material delivery assembly 34 may be configured to deliver a first component material into the first component material chamber 40 using gravity feed techniques, pressure feed techniques, suction feed techniques, or any other suitable method of delivery.
For example, in certain embodiments, a gravity feed reservoir may be coupled to the first component material inlet coupling 38 such that the forces of gravity cause the first component material to be delivered from the gravity feed reservoir into the first component material chamber 40. However, in other embodiments, a pressure feed reservoir may be coupled to the first component material inlet coupling 38 such that the pressure of the first component material in the pressure feed reservoir causes the first component material to be delivered from the pressure feed reservoir into the first component material chamber 40. In this embodiment, the pressure of the first component material in the pressure feed reservoir may be selectively adjusted based on operating conditions of the spray coating gun 12. For example, the pressure of the first component material may be selectively adjusted based on pressures and/or flow rates of a second component material, which may be delivered through a hollow center passage through the multiple component delivery needle 42. The selective adjustment of pressures and/or flow rates of the first and second component materials may be performed during calibration of the spray coating gun 12. In addition, in other embodiments, the first component material may be delivered from the first component material chamber 40 using suction feed techniques. In other words, the first component material may be siphoned out of the first component material chamber 40 from a low pressure area created by the pressurized flow of the second component material from the hollow center passage of the multiple component delivery needle 42.
In addition, the multiple component delivery needle 42 may be configured to at least partially control the flow rate of the first component material from the first component material chamber 40 through the fluid tip exit 30 of the fluid delivery tip assembly 18. The multiple component delivery needle 42 includes an enlarged body portion 46 extending moveably through the body 16 between the fluid delivery tip assembly 18 and a fluid valve 48. In certain embodiments, the fluid valve 48 may include a spring 50 that enables the fluid valve 48 to bias the multiple component delivery needle 42 toward the fluid delivery tip assembly 18. The enlarged body portion 46 of the multiple component delivery needle 42 is also coupled to a trigger 52, such that the enlarged body portion 46 (and the multiple component delivery needle 42) may be moved away from the fluid delivery tip assembly 18 as the trigger 52 is rotated counter clockwise about a pivot joint 54. However, any suitable inwardly or outwardly openable valve assembly may be used within the scope of the present embodiments.
An air supply assembly 56 is also disposed in the body 16 to facilitate atomization at the spray formation assembly 22. The illustrated air supply assembly 56 extends from an air inlet coupling 58 to the air atomization cap 24 via air passages 60 and 62. The air supply assembly 56 also includes a variety of seal assemblies, air valve assemblies, and air valve adjusters to maintain and regulate the air pressure and flow rate through the spray coating gun 12. For example, the illustrated air supply assembly 56 includes an air valve assembly 64 coupled to the trigger 52, such that rotation of the trigger 52 about the pivot joint 54 opens the air valve assembly 64 to allow air flow from the first air passage 60 to the second air passage 62. The air supply assembly 56 also includes an air valve adjustor 66 coupled to an air needle 68, such that the air needle 68 is movable via rotation of the air valve adjustor 66 to regulate the air flow to the air atomization cap 24. As illustrated, the trigger 52 is coupled to both the fluid needle valve assembly 44 and the air valve assembly 64, such that fluid and air simultaneously flow to the spray tip assembly 14 as the trigger 52 is pulled toward a handle 70 of the body 16. Once engaged, the spray coating gun 12 produces an atomized spray with a desired spray pattern and droplet distribution of the mixture of the first and second component materials.
More specifically, as the trigger 52 is pulled toward the handle 70 of the body 16, the multiple component delivery needle 42 is unseated from the fluid delivery tip assembly 18 and moves inwardly away from the fluid delivery tip assembly 18 such that the first component material is allowed to flow from the first component material chamber 40 through the fluid tip exit 30 of the fluid delivery tip assembly 18. At the same time, in certain embodiments, a valve end 72 of the multiple component delivery needle 42 may unseat the fluid valve 48, which may be coupled to a pressure vessel 74, allowing the second component material to flow through the hollow center of the multiple component delivery needle 42 to the atomization and mixing zone just outside the fluid tip exit 30. In this manner, the multiple component delivery needle 42 may proportionally control the flow of the first and second component materials. However, in other embodiments, the fluid valve 48 may be actuated by other components when the trigger 52 is pulled, enabling flow through the hollow center of the multiple component delivery needle 42. For example, in certain embodiments, the valve end 72 of the multiple component delivery needle 42 may include holes in its sides, such that when the holes are uncovered, the second component material flows into the hollow center passage. In addition, in other embodiments, a rotary valve may be used to enable the flow of the second component material through the hollow center passage of the multiple component delivery needle 42.
The pressure vessel 74 may be pressurized such that the flow of the second component material is pressure fed. As such, the pressure of the second component material in the pressure vessel 74 may be selectively adjusted based on operating conditions of the spray coating gun 12. For example, the pressure of the second component material may be selectively adjusted based on pressures and/or flow rates of the first component material delivered from the first component material chamber 40 around the multiple component delivery needle 42. The selective adjustment of pressures and/or flow rates of the first and second component materials may be performed during calibration of the spray coating gun 12. However, in other embodiments, the second component material may also be gravity fed, suction fed, or delivered using any suitable feeding techniques.
As described above, the second component material may flow through the center of the hollow multiple component delivery needle 42 toward the fluid tip exit 30 of the fluid delivery tip assembly 18. As such, the first and second component materials are not premixed. Rather, the first and second component materials may be delivered to the front of the spray coating gun 12, where the first and second component materials are mixed external to the spray coating gun 12 during atomization. The hollow center passage may extend axially through at least a portion of the multiple component delivery needle 42. In other words, in certain embodiment, the hollow center passage may not extend axially through the entire length of the multiple component delivery needle 42. Rather, the hollow center passage may only extend halfway through the multiple component delivery needle 42, with the second component material exiting at a different location than in the embodiment where the hollow center passage extends through the entire length of the multiple component delivery needle 42.
However, when the trigger 52 is being pulled, the multiple component delivery needle 42 moves away from the fluid tip exit 30 of the fluid delivery tip assembly 18, as illustrated by arrow 78 in
Because the second component material is pressurized due to the pressure in the pressure vessel 74, the second component material may generally flow from the hollow center of the multiple component delivery needle 42 through the fluid tip exit 30 of the fluid delivery tip assembly 18 along a common axis 84 of the multiple component delivery needle 42, the fluid delivery tip assembly 18, and the air atomization cap 24, as illustrated by arrow 86. However, the manner in which the first component material flows from the first component material chamber 40 through the fluid tip exit 30 of the fluid delivery tip assembly 18 may depend on whether the first component material is gravity fed, pressure fed, or suction fed into the first component material chamber 40.
For example,
Conversely,
In certain embodiments, when the multiple component delivery needle 42 is in a closed position, the tip 76 of the multiple component delivery needle 42 may extend past the front of the fluid tip exit 30. When the trigger 52 is pulled, the tip 76 of the multiple component delivery needle 42 may be approximately flush with the fluid tip exit 30. However, in other embodiments, when the multiple component delivery needle 42 is in a closed position, the tip 76 of the multiple component delivery needle 42 may be approximately flush with the fluid tip exit 30. When the trigger 52 is pulled, the tip 76 of the multiple component delivery needle 42 may be recessed inwardly within the fluid tip exit 30.
In any case (e.g., gravity feeding, suction feeding, or pressure feeding of the first component material), the first and second component materials are not premixed inside the spray coating gun 12. Rather, the first and second component materials are delivered to the front of the spray coating gun 12, where the first and second component materials are mixed external to the spray coating gun 12 during atomization. However, in other embodiments, depending on the operating parameters (e.g., flow rate and/or pressure) of the first and second component materials, a certain amount of the mixing may actually occur near to or inside of the fluid tip exit 30 of the fluid delivery tip assembly 18. For example, the first and second component materials may be mixed where the first component material chamber 40 meets the fluid tip exit 30 of the fluid delivery tip assembly 18.
In certain embodiments, the multiple component delivery needle 42 may have guides to help maintain concentricity within the interior of the fluid delivery tip assembly 18. For example,
As described above, the multiple component delivery needle 42 includes a hollow center through which the second component material flows from the pressure vessel 74. In addition, as described above, the first component material flows from the first component material chamber 40 within the fluid delivery tip assembly 18 through the space between the fluid tip exit 30 of the fluid delivery tip assembly 18 and the exterior surface 102 of the multiple component delivery needle 42 when the trigger 52 is pulled. To aid the flow of the first component material through the fluid tip exit 30, in certain embodiments, the multiple component delivery needle 42 may include a plurality of openings 104 along the exterior circumferential surface 102 of the multiple component delivery needle 42.
For example,
The openings 104 may generally be defined as indentions that extend axially along the exterior surface 102 near the tip 76 of the multiple component delivery needle 42. Any number of openings 104 may be used on the exterior circumferential surface 102 of the multiple component delivery needle 42. For example, in certain embodiments, the multiple component delivery needle 42 may include 2, 3, 4, 5, 6, or more openings 104. In addition, in the embodiment illustrated in
The multiple component delivery needle 42 of
Just upstream of the terminal wall 114, a plurality of exit holes 116 may be in fluid connection with the hollow center 112 of the multiple component delivery needle 42. The exit holes 116 may extend from the hollow center 112 at least partially radially and may seal against a tapper or other means within the fluid delivery tip assembly 18. In other words, when the trigger 52 is not being pulled and the multiple component delivery needle 42 abuts the fluid tip exit 30 of the fluid delivery tip assembly 18, the flow of the second component material through the hollow center 112 and the exit holes 116 of the multiple component delivery needle 42 may be impeded. However, when the trigger 52 is being pulled and the multiple component delivery needle 42 pulls away from the fluid tip exit 30 of the fluid delivery tip assembly 18, the flow of the second component material through the hollow center 112 and the exit holes 116 of the multiple component delivery needle 42 may be enabled. In this manner, the second component material may begin mixing with the first component material from the first component material chamber 40 just downstream of the exit holes 116. As such, the exit holes 116 against the fluid tip exit 30 of the fluid delivery tip assembly 18 may function as a valve, which may supplement and/or replace the functioning of the fluid valve 48 near the valve end 72 of the multiple component delivery needle 42 of
In addition, in certain embodiments, the first and second component materials may be fed from generally the same inlet location. For example, in certain embodiments, the second component material may not be fed from the valve end 72 of the multiple component delivery needle 42. Rather, the second component material may be fed coaxially through the first component material inlet passage 36. More specifically, the second component material may be fed through a second component material passage, which is coaxial within the first component material inlet passage 36.
The first component material may still be fed into the first component material chamber 40 through the first component material inlet passage 36, as illustrated by arrows 122. However, as illustrated by arrow 124, the second component material may be fed through the second component material tube 120, which defines the second component material inlet passage 118 within the first component material passage 36. Therefore, the hollow center 112 of the multiple component delivery needle 42 may only extend through the multiple component delivery needle 42 from the tip 76 of the multiple component delivery needle 42 to approximately where the second component material inlet passage 118 fluidly connects to the multiple component delivery needle 42.
The second component material may be fed into the hollow center 112 of the multiple component delivery needle 42 through cross holes 126 in the multiple component delivery needle 42. The cross holes 126 may extend from the hollow center 112 of the multiple component delivery needle 42 to the exterior circumferential surface 102 of the multiple component delivery needle 42. In certain embodiments, the cross holes 126 may not be in fluid connection with the second component material inlet passage 118 when the trigger 52 is not being pulled. However, the cross holes 126 may be brought into fluid connection with the second component material inlet passage 118 when the trigger 52 is pulled and the multiple component delivery needle 42 moves away from the fluid tip exit 30 of the fluid delivery tip assembly 18, as illustrated by arrow 128. In certain embodiments, the first and second component materials may be fed through a cup-within-a-cup design, wherein the first component material is fed through a first cup 130 that is located around a second cup 132, which is used to feed the second component material.
In certain embodiments, the first component material may comprise paint, whereas the second component material may comprise an activator (e.g., thinner). However, in other embodiments, different liquids may be used as the component materials with the disclosed embodiments. In other words, the multiple component delivery needle 42 and associated components of the spray coating gun 12 may have applications with various types of plural component materials, and are not limited to paints and activators. In addition, although the disclosed embodiments disclose the use of two component materials, in other embodiments, more than two component materials may be used. For example, in certain embodiments, the hollow center passage within the multiple component delivery needle 42 may actually include two independent half-circle flow paths, or two parallel circular or non circular flow paths. As such, more than one component material may flow through the hollow center passage of the multiple component delivery needle 42. In this embodiment, the multiple component delivery needle 42 may be coupled to a single fluid valve or more than one fluid valve to deliver the multiple component materials through the multiple hollow passages within the multiple component delivery needle 42.
The embodiments described herein enable the delivery of the first component material between the fluid tip exit 30 of the fluid delivery tip assembly 18 and the exterior surface 102 of the multiple component delivery needle 42 while enabling the delivery of the second component material from the hollow center of the multiple component delivery needle 42. As described above, the delivery of the first and second component materials may be synchronized such that the first and second component materials mix in an appropriate ratio. By not premixing the first and second component materials, excess waste material created by the painter may be minimized because the painter only uses as much of the first and second component materials as needed. Further, because mixing of the first and second component materials generally occurs in front of the fluid tip exit 30 of the fluid delivery tip assembly 18, the disclosed embodiments may reduce cleanup time as well as provide the painter with more time before having to clean the components of the spray coating gun 12. As such, the disclosed embodiments provide a user friendly, compact way of spraying multiple component materials.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application is a continuation of U.S. patent application Ser. No. 14/462,206, entitled FLUID THROUGH NEEDLE FOR APPLYING MULTIPLE COMPONENT MATERIAL, filed Aug. 18, 2014, which is herein incorporated by reference in its entirely and which claims priority from and the benefit of U.S. patent application Ser. No. 12/765,699, entitled FLUID THROUGH NEEDLE FOR APPLYING MULTIPLE COMPONENT MATERIAL, filed Apr. 22, 2010, now U.S. Pat. No. 8,807,460, issued on Aug. 19, 2014, which is herein incorporated by reference in its entirely and which claims priority from and the benefit of, and incorporates by reference, each of the following: (a) U.S. Provisional Application Ser. No. 61/173,595, entitled FLUID THROUGH NEEDLE FOR APPLYING MULTIPLE COMPONENT MATERIAL, filed Apr. 28, 2009; and (b) U.S. Provisional Application Ser. No. 61/228,149, entitled FLUID DELIVERY SYSTEM FOR SPRAYING MULTIPLE COMPONENT MATERIAL, filed Jul. 23, 2009.
| Number | Date | Country | |
|---|---|---|---|
| 61173595 | Apr 2009 | US | |
| 61228149 | Jul 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14462206 | Aug 2014 | US |
| Child | 14550966 | US | |
| Parent | 12765699 | Apr 2010 | US |
| Child | 14462206 | US |
