This disclosure relates to air caps for liquid spray head assemblies and/or for liquid spray guns. Specifically provided are molded air caps with face geometry inserts. Face geometry inserts provided herein may be effective to provide symmetrical and balanced spray patterns.
Spray guns are known for use in the application of liquids such as paints (and other coatings) across many industries. Such spray guns commonly include a gun body, a trigger, a spray head assembly, a reservoir for holding a liquid to be sprayed, and an air source to assist in atomizing and propelling the liquid onto a surface to be coated. During use, the liquid may accumulate on the exterior and interior surfaces of the spray guns. Historically, spray guns were fabricated from metal and for a long-use life, which included reuse after cleaning and/or maintenance. Development of individual molded parts having a limited-use life for spray guns, including but not limited to, nozzles tips, air horns, and/or air caps, permits certain parts of spray guns to be easily cleaned and/or disposable to alleviate and/or mitigate the extensive use of cleaning chemicals and maintenance typically needed for metal or long-use components. These individual parts may contain air and/or liquid openings and alignment among the individual parts impacts a resulting spray pattern.
There is an on-going need for improved molded parts to reduce manufacturing costs, to increase precision in the fabricated parts, and to ensure desired performance of the spray guns.
In order to address ensuring individual parts fabricated for spray guns are aligned to deliver desired spray patterns, face geometry inserts have been developed. Specifically provided herein are molded air caps with face geometry inserts for use with liquid spray head assemblies and/or for liquid spray guns.
In a first aspect, provided are air caps for a liquid spray gun, the air caps comprising: a base member comprising: a base member body, at least one pair of exit air openings, and a nozzle tip opening; and a face geometry insert comprising a bridging portion and a pair of shaping air apertures and being retained to the base member body; wherein each aperture of the pair of shaping air apertures is located on an opposite side of a spray axis of the air cap.
Other features that may be used individually or in combination are as follows. Each aperture of the pair of shaping air apertures may be symmetric with respect to the spray axis. The face geometry insert may further comprise a center frame opening such that the center frame opening is concentric with the nozzle tip opening. The face geometry insert may further comprise at least one pair of capping features. The base member may further comprise at least one pair of capping features. The face geometry insert may further comprise at least one pair of auxiliary air holes. The base member may further comprise at least one pair of air horns that have the at least one pair of exit air openings. The face geometry insert may comprise at least one hinge. Or, the face geometry insert may comprise a non-planar body and no hinges.
In one or more of the disclosed embodiments, the face geometry insert is removable from the base member body. For example, the face geometry insert may snap-fit into the base member body. Or, the face geometry insert may bend-fit into the base member body.
In other disclosed embodiments, the face geometry insert is welded to the base member body.
All embodiments may further comprise a nozzle tip affixed to the face geometry insert. The nozzle tip may be removably affixed to the center frame of the face geometry insert. Or, the nozzle tip may be integral to the face geometry insert.
An included angle 0 with respect to the relation among the spray axis and a plane of each surface of the pair of shaping air apertures is in the range of 25° to 85°.
Another aspect provides a kit comprising a plurality of air caps as disclosed herein with one or more features of various sizes. For example, the pairs of shaping air apertures of at least two of the face geometry inserts may have different configurations and/or the center frame openings of at least two of the face geometry inserts may have different dimensions and/or nozzle tips of different dimensions may be included.
Further aspects provide a method of making an air cap, the method comprising: providing a face geometry insert comprising a bridging portion and a pair of shaping air apertures; providing a base member; and assembling the face geometry insert with the base member to form the air cap such that each aperture of the pair of shaping air apertures is located on an opposite side of a spray axis of the air cap. The face geometry insert may be fabricated by molding or stamping. The face geometry insert may be moved from an initial position to an assembled position upon assembly with the base member. The face geometry insert and the base member independently comprise a metal, a polymer, a ceramic, a filled material, or combinations thereof.
Another aspect is a spray head assembly for attachment to a liquid spray gun, the spray head assembly comprising a barrel and any of the air caps disclosed herein along with a nozzle tip.
Liquid spray guns are also provided, which comprise: spray head assembly as disclosed herein assembled with a liquid spray gun body.
These and other aspects of the invention are described in the detailed description below. In no event should the above summary be construed as a limitation on the claimed subject matter.
The accompanying drawings are included to provide a further understanding of the invention described herein and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments. Certain features may be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein:
The figures are not necessarily to scale. Like numbers used in the figures refer to like components. It will be understood, however, that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.
Provided are air caps for liquid spray head assemblies and/or for liquid spray guns. Specifically provided are molded air caps with face geometry inserts. Face geometry inserts provided herein are effective to provide a refined spray pattern, which is a spray pattern suitable for a desired application that is balanced, symmetrical, and has smooth transitions in coating spray density within the pattern. For smooth transitions, there are no excessively sharp changes in coating amount/density. When components for liquid spray guns are fabricated from metal, current methods used to manufacture these components may involve casting or machining where creating pathways for air and/or liquid flow, and in particular for atomization, usually requires using labor and/or capitol intensive secondary operations, such as precision drilling. The secondary operations are susceptible to variations in the size and positioning of critical air outlets. Moreover, with machining, certain geometries simply cannot be achieved due to the inability of drilling tools to reach all surfaces and desired angles. Even with molded components, both one-part and two-part, there are inefficiencies in fabrication and imprecise methods that could be improved. Shrinkage and distortion of molded parts, in view of, for example, design and wall thickness, can cause misalignment and part-to-part variation. Face geometry inserts, as described herein are beneficial in alleviating shortcomings in the prior art.
Through the use of the inventive face geometry inserts, designs of molded components for liquid spray guns are simplified and made more precise. Specifically, the face geometry inserts are components wherein the location, size, and spacing of critical air and/or liquid openings are already aligned/designed into a single piece
A face geometry insert is retained to a base member to form an air cap. The base member may be the larger of the two pieces, and it is fabricated easily as one piece without a need for precisely aligned features, such as primary/shaping air apertures/holes. The face geometry insert may be the smaller of the two pieces and its manufacture and the features therein may be precisely controlled with minimal variation in dimensions that are critical to correct operation. The base member may be fabricated as needed, as one part or a combination of parts.
In this way, the design/fabrication of air caps is simplified. Benefits include greater and improved control of positioning and size of paint atomization and pattern formation features. Face geometry inserts may be color-coded with base members and/or barrels for quick recognition of material/job specified combinations. The face geometry inserts described herein can be designed to achieve a variety of patterns as desired. Indeed, customized face geometry inserts may be combined (assembled) with a universal base member body in order to create a wide range of air cap configurations.
Generally, spray patterns are produced by liquid exiting a liquid nozzle port (also referred to as a fluid tip) of a barrel/nozzle, the port being centrally located within the center hole of an air cap and as such is surrounded by a center annular air outlet that channels compressed air and a pair of opposed inwardly directed shaping air apertures that also channel compressed air arranged on opposite sides and spaced forwardly of the center annular air outlet. In this way, the liquid emerging from the liquid nozzle port is mixed with air streams emerging from the center air outlet and from the inwardly directed shaping air apertures, which causes the liquid to atomize and form a spray for application to a substrate. Air streams or jets from the shaping air apertures may be adjustable to adapt the spray nozzle for dispensing different liquids and/or change the geometry of the spray pattern. Air streams from the auxiliary air holes in the air cap may further atomize the liquid and/or interact with the shaping air streams to further refine the spray pattern.
Face geometry inserts and base members may be fabricated by molding or stamping or other methods related to manipulating/processing plastics and/or metals known in the art. They may be fabricated in the same way or differently, by the same materials or different ones. In one or more embodiments, the fabrication methods include introducing first and second materials in their molten state to first and second molds, respectively, to create formed molten materials, and then cooling the formed molten materials. Suitable materials independently include, but are not limited to, metals, polymers, ceramics, and other materials such as glass, filled-materials, and ceramics.
Suitable metals include, but are not limited to, aluminum, copper, or steel, including combinations and/or alloys thereof. Suitable polymers independently include, but are not limited to, polyurethanes, polyolefins (e.g., polypropylenes), polyamides (e.g., nylons including amorphous nylons), polyesters, fluoropolymers, and polycarbonates), and others. The polymers may be opaque, translucent, or transparent as suitable for the application. Exemplary filled-material is glass-filled polypropylene. The molds can be designed with features, such as steel core pins that form resulting openings in the molded parts, the openings including but not being limited to shaping air apertures, auxiliary air holes, and center frame openings, and overall geometries as desired. In one or more embodiments, the face geometry insert is formed in one-step, including formation of its openings. In other embodiments, openings may be drilled, for example by laser drilling, in a separate step, Face geometry inserts may contain other features as desired to direct air.
Face geometry inserts may also be fabricated by stamping, for example by metal stamping. In addition, photolithographic methods that involve additive processes like metal plating and/or subtractive processes like chemical etching may be suitable for forming face geometry inserts and/or their features.
The face geometry insert may be changeable, flexible, and/or deformable as needed to permit it to go from an initial position to an assembled position upon assembly with or fitting into the base member. By “flex” it is contemplated that the face geometry insert is sufficiently flexible to bend over a least some portion of its length and is sufficient to achieve an included angle between shaping air streams of up to 85 degrees. That is, materials of construction have adequate elasticity and/or plasticity to allow change from an initial position to an assembled position. Also, the presence of hinges may facilitate assembly of the face geometry insert with the base member or the ability to deliberately distort the face geometry insert from its initial position, which is an unassembled configuration, into an assembled configuration by bending the face geometry insert at one or two or more predefined locations.
The face geometry insert may be snap-fit, bend-fit, welded, bonded, or otherwise retained to a base member such that a substantially tight seal is achieved. The seal may be air tight, or it may tolerate some venting. In this way, air exits the air caps through designed openings, including but not limited to a nozzle tip opening, shaping air apertures, and optional auxiliary air holes. The face geometry insert may, for example, be snap-fit onto or into the top side or underside of the base member. With snap-fit assembly, the face geometry insert may be removable; with welding, the face geometry insert usually is not removable. For welding, one method is ultrasonics, where an energy director may be present to ensure that the parts are correctly adhered to one another.
The base member may have one or more receiving features such as a slight recess, groove, and/or other locating feature that cooperates with the face geometry insert. With respect to aligning and registering parts, the face geometry insert, with its openings pre-designed and already precisely aligned onto a single piece, receipt into the base member ensures that the registration continues to be maintained upon assembly.
In one or more embodiments, the face geometry insert is removable from the base member. In one or more other embodiments, the face geometry insert is non-removable.
The face geometry insert may be shaped as needed, for example, an elongated body may be suitable when the air cap design includes a structure for exit air openings such as air horns. In other embodiments, the body of the face geometry insert may be disc-shaped, circular, oval, or even square. The face geometry insert comprises openings located in a bridging portion, which means the bridging portion is the material between the various openings including but not limited to shaping air apertures. The face geometry insert may contain as many openings or pairs of openings as needed. Some embodiments provide 2, 3, 4, 5, or more openings. It is understood that a base member of the air cap will be configured to deliver air as needed to the openings of the face geometry insert. The exit air openings may be formed, for example, through a surface of the body of the base member. An exit air structure, such as at least one pair of air horns, may be attached to or received by or integral with the base member body.
Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.
Turning to
Optional auxiliary air holes 117 may be formed in the face geometry insert 104. The base member 102 is configured as needed to supply/channel air to the auxiliary air holes 117 in the face member insert 104.
The base member 102 comprises at least one pair of exit air openings 107a, 107b, a base member body 116, and a nozzle tip opening 106. The exit air openings in this embodiment are formed through an exit air structure, such as at least one pair of air horns 108a, 108b as exemplified in
A spray axis 150 extends through the center of the nozzle tip opening 106 and the center frame opening 112. When a liquid nozzle port is present, the spray axis extends through the liquid nozzle port center also. Upon centering of air and/or liquid openings about the spray axis 150, alignment of air and/or liquid flow and/or symmetry of the spray pattern is achieved. As shown, each aperture of the pair of shaping air apertures is located on an opposite side of the spray axis 150. That is, shaping air aperture 110a is on an opposite side of spray axis 150 as compared to shaping air aperture 110b. Likewise, shaping air aperture 110c is on an opposite side of spray axis 150 as compared to shaping air aperture 110d. In one or more embodiments, the shaping air apertures 110a, 110b and/or 110c, 110d are symmetric with respect to the spray axis 150.
In one or more embodiments, pairs of apertures 110a, 110b and 110c, 110d are symmetric with respect to the spray axis 150. In
The base member 502 comprises at least one pair of exit air openings 507a, 507b, a base member body 516, and a nozzle tip opening 506. The base member may further comprise a receiving feature 514 for receiving the face geometry insert 504. The center frame opening 512 of the face geometry insert 504 may be axially and/or concentrically with the nozzle tip opening 506. Both openings may be independently shaped as desired. In some embodiments the openings are independently circular or oval or non-circular.
A spray axis 550 extends through the center of the nozzle tip opening 506 and the center frame opening 512. When a liquid nozzle tip is present, the spray axis extends through the center of the liquid nozzle port also. Upon centering of air and/or liquid openings about the spray axis 550, alignment of air and/or liquid flow and/or symmetry of the spray pattern is achieved. As shown, each aperture of the pair of shaping air apertures is located on an opposite side of the spray axis 550. That is, shaping air aperture 510a is on an opposite side of spray axis 550 as compared to shaping air aperture 510b. Likewise, shaping air aperture 510c is on an opposite side of spray axis 150 as compared to shaping air aperture 510d. In one or more embodiments, the air apertures 510a, 510b and/or 510c, 510d are symmetric with respect to the spray axis 550.
In one or more embodiments, the pair of apertures 510a, 510b (not shown in
With respect to
Optionally, nozzle tips may be attached onto the liquid nozzle port 352 and/or face geometry insert 304. Exemplary nozzle tips are provided in WO2012/109298 (Joseph), commonly assigned and incorporated herein by reference. Positioning of the pair of shaping air apertures, the center frame opening, and the nozzle tip may be effective to provide a refined spray pattern from the liquid spray gun. In
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the appended claims and their equivalents.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2014/045544 | 7/7/2014 | WO | 00 |
Number | Date | Country | |
---|---|---|---|
61846309 | Jul 2013 | US |