The present technique relates generally to spray systems and, more particularly, to industrial spray coating systems. In particular, a system and method is provided for improving spray formation in a spray coating device with an air-assisted spray cap.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present system and techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Spray coating devices are used to apply a spray coating to a wide variety of product types and materials, such as wood and metal. An operator may select a particular tip assembly for a spray coating device for forming the desired spray, which may depend on the type of fluid being applied as well as the target object. In particular, for applications in which a fine spray is desired, a tip assembly may include components for shaping the atomized spray into a desired pattern, e.g., a fan shape. However, because such structures provide an additional pathway for the atomized fluid, which generally emerges from an orifice coupled to the spray device, spray-shaping tip assemblies may become clogged or may leak. Accordingly, a technique is needed for a tip assembly that provides a fine spray pattern without clogging to provide more consistent spray formations.
The present technique provides a system and method for spray shaping in a spray coating device by providing an air cap tip assembly with improved spray shaping characteristics. The spray gun includes an adjustable air valve that is rotatable about an axis. Valve rotation alters the air pressure and/or air flow, thereby adjusting the shape of the spray pattern. In addition, rotation of the twist tip about the axis reduces clogging of the atomization tip, by pushing out any paint residue that may have been blocking the paint flow inside of the atomization tip. The resulting spray device has improved ability to vary the spray pattern without requiring the operator to change the spray tip. The air cap includes a unique configuration of air-assist air channels about the spray exit point on the air cap to improve the shape characteristics of the exiting spray. In addition controlling the spray pattern shape, the specific configuration of the air flow stream from the air cap, eliminates the paint “tail patterns” associated with smaller twist tip orifice sizes.
The foregoing and other advantages and features of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
As discussed in detail below, the present technique provides spray tip assembly including an air cap for coating and other spray applications. The spray tip assembly includes a twist tip that is rotatable about an axis such that rotation of the twist tip results in an alteration in the angle or direction of the fluid flow passageway exiting the air cap. The twist tip allows an operator to adjust the fluid flow and the spray pattern and/or spray shape or geometry. Further, the twist tip may be inserted from the top or bottom of the air cap, allowing greater flexibility and control.
In addition, the air cap includes surface features on an integral sleeve that help shape the spray pattern. The surface features include air-assist channels that spray air outwardly from the spray device and interact with the atomized spray at a point forward (e.g., downstream) of the spray gun tip to help form a desired spray pattern. As provided, the air-assist channels are located at least in part in a depression in the surface of the integral sleeve, such that the air ejection ports of the air-assist channels are not level with other portions of the exterior surface of the integral sleeve. That is, the air ejection ports may be angled relative to the fluid ejection passageway. Further, the surface features of the integral sleeve may also include one or more grooves. The relationship between the air-assist channels, the grooves, and the fluid opening bore allow the air-assist features to shape the spray in a desired pattern.
The spray coating system 10 of
The twist tip assembly 200 includes a twist tip 210 that is configured to be inserted into an air cap 212. The twist tip assembly 200 may also include a finger guard 216. In addition, the twist tip assembly 200 may include additional retaining elements that may, at least in part, function to couple the twist tip assembly 200 to the body 202. As discussed in more detail below, the twist tip assembly 200, when applied to the body 202, provides an internal passage 220 (e.g., that includes one or more passages formed by the particular arrangement and alignment of components of the twist tip assembly 200) that directs the flow of fluid from fluid passage 222 downstream, as shown by arrow 224 to an ejection port 225, from which atomized fluid is ejected to form a spray or other suitable pattern. Accordingly, the internal passage 220 of the twist tip assembly 200 aligns with fluid passage 222 when the twist tip assembly 200 is coupled to the body 202.
The body 202 of the spray coating device 12 includes a variety of controls and supply mechanisms for the twist tip assembly 200. As illustrated, the body 202 includes a fluid delivery assembly 226 having a fluid passage 228 extending from a fluid inlet coupling 230 to the fluid delivery tip assembly 204. The fluid delivery assembly 226 also comprises a fluid valve assembly 232 to control fluid flow through the fluid passage 222 and to the fluid delivery tip assembly 204. The illustrated fluid valve assembly 232 has a needle valve 234 extending movably through the body 202 between the fluid delivery tip assembly 204 and a fluid valve adjuster 236. The fluid valve adjuster 236 is rotatably adjustable against a spring 238 disposed the needle valve 234 and an internal portion 242 of the fluid valve adjuster 236. The needle valve 234 is also coupled to a trigger 244, such that the needle valve 234 may be moved inwardly away from the fluid delivery tip assembly 204 as the trigger 244 is rotated counter clockwise about a pivot joint 246. However, any suitable inwardly or outwardly openable valve assembly may be used within the scope of the present technique. The fluid valve assembly 232 also may include a variety of packing and seal assemblies, such as packing assembly 248, disposed between the needle valve 234 and the body 202.
An air supply assembly 250 is also disposed in the body 202 to facilitate atomization at the twist tip assembly 200. The illustrated air supply assembly 250 extends from an air inlet coupling 252. The air supply assembly 250 also includes a variety of seal assemblies, air valve assemblies, and air valve adjusters to maintain and regulate the air pressure and flow through the spray coating device 12. For example, the illustrated air supply assembly 250 includes an air valve assembly 258 coupled to the trigger 244, such that rotation of the trigger 244 about the pivot joint 246 opens the air valve assembly 258 to allow air flow from the air passage 254 to the air passage 256. The air supply assembly 250 also includes an air valve adjustor 260 coupled to a needle 262, such that the needle 262 is movable via rotation of the air valve adjustor 260 to regulate the air flow to the twist tip assembly 200. As illustrated, the trigger 244 is coupled to both the fluid valve assembly 232 and the air valve assembly 258, such that fluid and air simultaneously flow to the twist tip assembly 200 as the trigger 244 is pulled toward a handle 264 of the body 202. Once engaged, the spray coating device 12 produces an atomized spray with a desired spray pattern and droplet distribution. Again, the illustrated spray coating device 12 is only an exemplary device of the present technique. Any suitable type or configuration of a spraying device may be used in conjunction with the twist tip assembly 200 as provided.
The twist tip 210 also includes an extending portion 292 that is sized and shaped to be inserted into a first bore 294 in the air cap 212. When the twist tip 210 is inserted into the first bore 294 of the air cap 212, the integral bore 290 may be aligned with a second bore 296 by rotating the twist tip 210. In this manner, the integral bore 290 may be aligned along the axis 298 of the internal passage 220. As illustrated, the first bore 294 and the second bore 296 are substantially orthogonal to one another. Further, rotation of the twist tip 210 may also change the angle and alignment of the internal bore 290, which may cause the ejection port 225 to be rotated off-axis from axis 298. In this manner, an operator may change the angle and/or direction of flow out of the spray device 12. Although the twist tip 210 is shown as being inserted into a top 299 of the integral bore 294 (e.g., in
The twist tip 210 also includes a protrusion 300 that is sized and shaped to interact with a top surface 302 of the air cap 212 to prevent any further downward insertion of the twist tip into the first bore 294 than is needed to align the integral bore 290 with the axis 298. The protrusion 300 is positioned along the extending portion 292 to facilitate this alignment. In addition, the protrusion 300, through interaction with rear surface 304, may define the degree of rotation for the twist tip 210. Further rotation of the twist tip 210 is prevented at the point at which the abutment surface 306 of the protrusion abuts against the rear surface 304.
The air cap 212 may also include mating features for coupling to additional components of the twist tip assembly 200. Further, the air cap 212 is a separate removable part from the twist tip 210 and may be removed from other components of the twist tip assembly 200. As illustrated, the air cap 212 may include a groove or channel 310 that is configured to mate with a complementary feature on the finger guard 216. The finger guard 216 has a cylindrical bore 318 that accommodates a cylindrical portion 311 of the air cap 212. In addition, the air cap 212 may include one or more threads (e.g., female or male threads) 314 or other mating features sized and shaped to mate with a complementary threads 315 (e.g., male or female threads) on a retaining nut 317. It should be understood that complementary mating features may include threads (e.g., male and female), notches and recesses, ridges and grooves, or other features to facilitate coupling of the twist tip assembly 200. The air cap 212 also includes an exterior surface 316 with spray shaping features as discussed in detail below.
The twist tip assembly 200 may also include a core portion 320 that is configured to fit inside of the air cap 212. The core portion 320 includes a first bore 322 and a second bore 324 that are sized and shaped to align with the first bore 294 and the second bore 296 of the air cap 212 to define the internal passage 222 when the core portion 320 is inserted into the passageway defined by the second bore 296. The core portion 320 may also include mating features 326 that may mate with complementary features on a mounting component 327 and/or the air cap 212. In addition, the core portion 320 may include a front surface 328. The front surface 328, when inserted into the air cap 212, aligns with the exterior face 316 of the air cap 212. As such, the front surface 328 may be shaped or otherwise formed to incorporate the spray shaping features of the exterior face 316.
The core portion 320 may be coupled to the mounting component 327 by a brace piece 334 and a washer 330. The brace piece 334 includes a shaped surface 335 and one or more mating components 337 for coupling the brace piece 334 and washer 330 to the mounting component 327. To that end, portions of the brace piece 334, such as surface 335, may be shaped or curved to facilitate the coupling. Both the brace piece 334 and the washer 330 include respective bores 336 and 332 along the axis 298 that further define the internal passage 220. Generally, the internal passage is aligned along the axis 298. However, a portion of the passage 220 defined by the bore 290 may be rotated off-axis from the axis 298 via rotation of the twist tip 210. In addition, bores 322 and 294 align along axis 214 to form a receptacle for insertion of the twist tip 210. As such, when the retaining nut 317, the mounting component 327, the brace piece 334, the washer 330, the core portion 320, the air cap 212, the twist tip 210, and the finger guard 216 are assembled, bores 340, 336, 332, 324, 296, 290, and 318 all align to form the internal passage 220.
As noted, the internal passage 220 includes a portion defined by the bore 290.
As illustrated in
In addition, the twist tip assembly 200 may include surface features for shaping a spray. As illustrated in
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4165836 | Eull | Aug 1979 | A |
4776368 | Drozd | Oct 1988 | A |
5280853 | Perret, Jr. | Jan 1994 | A |
5749528 | Carey et al. | May 1998 | A |
5765753 | Kieffer | Jun 1998 | A |
6390386 | Krohn et al. | May 2002 | B2 |
6481640 | Carey et al. | Nov 2002 | B1 |
7028916 | Micheli | Apr 2006 | B2 |
7311271 | Micheli | Dec 2007 | B2 |
7568635 | Micheli | Aug 2009 | B2 |
7762476 | Micheli | Jul 2010 | B2 |
7789327 | Micheli et al. | Sep 2010 | B2 |
20040031860 | Micheli | Feb 2004 | A1 |
20040046040 | Micheli | Mar 2004 | A1 |
20040262416 | Micheli | Dec 2004 | A1 |
20050006498 | Micheli | Jan 2005 | A1 |
20060000928 | Micheli | Jan 2006 | A1 |
20060065760 | Micheli | Mar 2006 | A1 |
20060214027 | Micheli | Sep 2006 | A1 |
20070221762 | Micheli et al. | Sep 2007 | A1 |
20080017734 | Micheli et al. | Jan 2008 | A1 |
20080048055 | Micheli | Feb 2008 | A1 |
20080185009 | Choncholas et al. | Aug 2008 | A1 |
20080295768 | Micheli et al. | Dec 2008 | A1 |
20080296409 | Micheli | Dec 2008 | A1 |
20090148612 | Micheli | Jun 2009 | A1 |
20090230218 | Drozd | Sep 2009 | A1 |
20090277976 | Micheli et al. | Nov 2009 | A1 |
20090302133 | Micheli et al. | Dec 2009 | A1 |
20100006673 | Micheli | Jan 2010 | A1 |
20100050870 | Gajjar et al. | Mar 2010 | A1 |
20100108784 | Drozd et al. | May 2010 | A1 |
Number | Date | Country |
---|---|---|
0215572 | Dec 1986 | EP |
215572 | Mar 1987 | EP |
Number | Date | Country | |
---|---|---|---|
20120097772 A1 | Apr 2012 | US |