• 专利附录
  • 专利说明
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  • 类似技术
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    • 专利摘要:
    A spray gun (10, 40) for coating articles with a powder coating material may optionally be operated with a thin-flow pump (24) or dense-flow pump (48) for a dilute or dense phase of the powder coating material. The spray gun comprises a gun body (12, 13, 12 ', 13') having a front portion (26, 26 ') with a spray nozzle (20, 20') and a rear portion (28, 44). A powder flow path (P, P1, P2) extends through the front portion (26, 26 ') and the rear portion (28, 44) and has an inlet end (16, 16') and an outlet end (18, 18 ') wherein powder coating material can flow from the inlet end (16, 16 ') to the outlet end (18, 18') and to the spray nozzle (20, 20 '). The front portion (26, 26 ') is designed for operation with a dilute phase of the powder coating material and is assembled with a first or second rear portion (28, 44). The first rear portion (28) is designed for operation with a dilute phase of the powder coating material. The second rear portion (44) is designed for operation with a dense phase of the powder coating material.
    公开号:CH708403B1
    申请号:CH01884/14
    申请日:2013-03-07
    公开日:2016-03-15
    发明作者:Terrence M Fulkerson；Brian D Mather；Benjamin J Becker
    申请人:Nordson Corp；
    IPC主号:
    专利说明:

    Technical field of the disclosure
    [0001] The invention generally relates to material applicators used for spraying powder coating material onto a workpiece or object. More particularly, the invention relates to a powder spray gun which receives powder coating material in a thin stream or dense stream.
    Background of the Revelation
    A material applicator is used to apply powder coating material to an object, part or other workpiece or surface. A material applicator is also referred to herein as a spray gun. The powder coating material may be supplied from a powder pump to a dilute or thin-flow spray gun or in dense phase or dense stream. Thin flow refers to a stream of powder that is a lean mixture or, in other words, has a large ratio of flow air to powder. Thin-flow powder pumps are most commonly used in the form of a venturi pump, which uses a large volume of air to draw powder from a supply and push the powder to the spray gun. Dense flow refers to a powder flow that is a rich mixture, or in other words, has a low ratio of flow air to powder. Sealing pumps are often used in the form of a pumping chamber that uses pressure to fill and empty a pumping chamber, but with a low air flow rate, hereafter referred to as flow air. Because dense flow systems use less flow air, the powder hoses may be smaller in diameter than compared to powder hoses used in thin flow systems.
    Summary of the Revelation
    A spray gun may optionally be configured to be operated with a dense phase pump or a thin-flow pump for obtaining powder coating material, for example, in dense flow, such as from a dense phase pump or, for example, in a thin stream, such as a venturi pump. In a more specific embodiment, the spray gun includes a front portion connectable to one of two selectable rear portions, and a powder flow path having an inlet end and an outlet end. The first selectable rear portion defines a constant cross-sectional area of the powder flow path from the inlet end of the powder flow path to the outlet end of the powder flow path. The second selectable rear portion includes a portion of the powder flow path, wherein the portion of the powder flow path has a first cross sectional area and a second cross sectional area with a transition region of the powder flow path connecting the first cross sectional area and the second cross sectional area, wherein the first cross sectional area is different than the second cross sectional area is. In another embodiment, the transition region includes an element for adding air to the powder coating material which flows into the second cross-sectional area. In another embodiment, the constant cross-sectional area is defined by a one-piece powder tube extending from the powder flow path inlet end to the powder flow path outlet end.
    [0004] In an embodiment illustrated in the disclosure, a spray gun includes a powder flow path having an inlet end and an outlet end, the powder flow path having a first part with a first cross-sectional area, a second part with a second cross-sectional area, and a transition area with an expansion chamber which connects the first part and the second part. In another exemplary embodiment, the first cross-sectional area is smaller than the second cross-sectional area. In another embodiment, the first part of the powder flow path is adapted to receive a powder from a dense phase pump. In another embodiment, the second part is adapted to direct a flow of powder to a Dünnstromdüse. In other embodiments, the spray gun may include a rod support or tube support design.
    In another embodiment, a spray gun includes a powder flow path having an inlet end and an outlet end, the powder flow path having a first part with a first cross-sectional area, a second part with a second cross-sectional area, and a transition area with an expansion chamber first part and the second part connects. The transition region includes an element for adding air to the powder coating material which flows into the second cross-sectional area. In an exemplary application, the spray gun receives powder from a dense phase pump and sprays powder into a thin stream through a spray nozzle. In yet another embodiment, the flow air added to the powder may be adjustable to adjust or select the air / powder ratio that flows through the second cross-sectional area.
    In another embodiment, the element for adding air to the powder stream may be a wear part which is easily replaceable without dismantling the spray gun, in particular the spray gun body. In other embodiments, the spray gun may include a rod support or tube support design.
    In all embodiments, the spray guns may optionally have a rod support design or a tube support design. The spray guns may also optionally have a manual design or an automatic design. The spray guns may also optionally provide a charging electrode which is connectable to a high voltage source for applying an electrostatic charge to the powder coating material during a coating operation.
    These and other aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the embodiments with reference to the accompanying drawings.
    Brief description of the drawings
    [0009]<Tb> FIG. Fig. 1 is a schematic illustration of a prior art spray gun operating with a thin flow powder;<Tb> FIG. FIG. 2 is a schematic illustration of a spray gun in accordance with the teachings and inventions in the present disclosure; FIG.<Tb> FIG. Fig. 3 is a three-dimensional view of a first embodiment of a hybrid spray gun in a pipe mount design;<Tb> FIG. FIG. 4 is a side view of the hybrid spray gun of FIG. 2 in longitudinal cross-section; FIG.<Tb> FIG. Fig. 5 is a three-dimensional view of an air diffuser subassembly that may be used with the spray gun of Fig. 2;<Tb> FIG. Fig. 6 is a three-dimensional exploded rear view of a partition used in the spray gun of Fig. 2;<Tb> FIG. Fig. 7 is a three-dimensional exploded front view of the partition of Fig. 6;<Tb> FIG. Fig. 8 is a magnified view of a transition section of the spray gun of Fig. 4;<Tb> FIG. Fig. 9 is a partial cross-sectional view in partial perspective of the transition section of the spray gun of Fig. 4;<Tb> FIG. Fig. 10 <SEP> is an enlarged view of the front part of the spray gun of Fig. 4;<Tb> FIG. Fig. 11 is a view of Fig. 10 rotated 90 degrees about the longitudinal axis of the spray gun;<Tb> FIG. Fig. 12 <SEP> is an embodiment of a hybrid spray gun in a stick holder embodiment;<Tb> FIG. 13 <SEP> is an embodiment of a manual hybrid spray gun in longitudinal cross-section;<Tb> FIG. 14 <SEP> is an enlarged view of the circled area of FIG. 13;<Tb> FIG. Fig. 15 shows a spray gun known in the prior art in longitudinal cross section in a rod support embodiment;<Tb> FIG. Fig. 16 shows a spray gun known in the prior art in longitudinal cross-section in a pipe support embodiment; and<Tb> FIG. 17 is a schematic illustration of an exemplary dense phase flow pump that may be used with the present invention.
    Detailed Description of the Exemplary Embodiments
    Although the inventions have been described in terms of various embodiments of spray guns with specific configurations, those skilled in the art will readily appreciate that the inventions can be used and used with many different types of spray gun designs. For example, automatic spray guns may have other mount styles than the stick mount or pipe mount, and manual guns may have many different embodiments. An automatic spray gun is one that is typically mounted on a support structure that can move the spray gun to a position for a coating operation, with the spray gun actuation (eg, turn on and turn off times to control spraying) being electronically controlled. A handheld spray gun is typically manually gripped by an operator and manually triggered to start and stop a coating operation. The exemplary embodiments also use an electrode connectable to a high voltage power supply, such as a multiplier, to deliver an electrostatic charge to the powder coating material, but the inventions can also be used with non-corona spray type spray guns. For example, the inventions can be used with tribocharging electrostatic spray guns or non-electrostatic spray guns.
    Specific embodiments of the various components used with the spray guns disclosed herein are exemplary and may be changed depending on the particular spray gun design and application.
    A powder coating process, or coating process, as used herein, refers to the conventional method using a spray gun to produce a cloud of powder coating material directed at an object to be coated. Powder coating operations may be electrostatic or non-electrostatic, as is well known.
    The term "hybrid" or "hybrid design" is used herein as a suitable reference to a spray gun, in accordance with the teachings of the present disclosure and inventions, which receives a dense phase powder phase from a powder pump, for example, a dense phase pump which provides a dense flow or stream of powder in the spray gun through a first flow channel diameter; and wherein the hybrid spray gun has a forward section that sprays powder that has been diluted by adding air into the dense phase powder phase within the spray gun. For example, the front portion of the spray gun may be the same as a spray gun used with powder supplied by a venturi pump. Thus, it is a "hybrid design" in which a dense powder phase and a dilute powder phase flows through the spray gun. The hybrid spray gun may also provide an expansion chamber within the powder spray gun which flows to a spray nozzle via a second flow channel diameter that is greater than the first flow channel diameter.
    Those skilled in the art will recognize that powder flow channels, such as provided by powder tubes, typically have a cylindrical shape, but non-cylindrical lines may alternatively be used. Such powder tubes have an internal cross-sectional area, but not necessarily an inside diameter. For cylindrical powder tubes, the diameter is an adequate reference for comparing powder tubes of different sizes. Therefore, in the present disclosure, we generally refer to diameters of exemplary powder tubes. However, we do not exclude from the scope of inventions, the alternative use of non-tubular powder tubes, with reference to the cross-sectional areas in terms of size comparison.
    Although the exemplary embodiments are described with respect to use with venturi pumps that generate a thin-flow powder phase and dense-flow pumps that produce a dense phase powder phase, such terms should not be considered as limiting the use and scope of the inventions be interpreted. Accurate definitions of dilute phases or dense flow and dense phases or dense flow are not critical to the present inventions, as the inventions of spray guns allow them to be combined with thin-flow powder phases, dense phase powder phases or powder flows over a continuum of air / powder ratios between dense stream and thin current can be operated. But for the purposes of the description, a thin-flow powder phase is the type of powder flow created by a venturi-type powder pump such that the powder flow has a lean mixture of powder to air due to the large volume or amount of flow air (compared to FIG a dense phase powder pump) generated by the Venturi pump. A dense phase powder phase is the type of powder flow produced by a dense phase pump in which the powder flow has a rich mixture of powder to air due to the small volume or amount of flow air (as compared to a venturi pump) which passes through one Density pump is generated. Sealing pumps, due to the use of less flow air, have smaller powder hose diameters that provide dense powder phases on a spray gun compared to powder hoses that provide low flow of venturi pumps. For the basic concepts and embodiments herein, a dense phase powder phase is a powder flow produced by a dense phase pump having a rich mixture of powder to air as compared to a low flow powder phase produced by a venturi pump.
    In the introduction, the present disclosure presents an invention as embodied in the examples, which is illustrated in the drawings and explained in the description. Such an inventive concept contemplates a configurable spray gun having two or more selectable embodiments. In one embodiment, a configurable spray gun in a first embodiment may include a forward section that is used to spray a lean powder stream mixture supplied by a thin-flow pump, such as a venturi-type pump. The thin-flow powder phase is fed to a first selectable rear section of the spray gun. Or alternatively, in a second embodiment, the configurable spray gun may be a hybrid spray gun in which the forward section may be selectively used to spray powder supplied as a rich powder stream mixture from a dense phase flow pump to a second selectable rear portion of the spray gun becomes.
    [0017] A spray gun receives a powder stream from a dense phase flow pump, for example, a powder stream mixture that is richer than a powder flow mixture produced by a venturi pump, but sprays the powder through a spray nozzle which is otherwise suitable for use with Coating operations are used which use powders fed through a venturi pump.
    In another embodiment, a spray gun provides a transition region of a powder flow path that adjusts to different powder flow path cross-sectional areas for thin flow and dense flow, regardless of whether a particular powder stream or a pump that supplies the powder stream to the spray gun is recognized Definition of thin stream or dense stream or otherwise fit into an air / powder ratio, which is different than what is otherwise referred to as dense stream or thin stream. The transition from a richer powder stream to a leaner powder stream may optionally be accomplished by adding air through an element in the richer powder stream.
    In another embodiment, a structure allows a quick and easy replacement of a Verschleissteiles in a spray gun, without disassembling the gun body. In one embodiment, the wear member may be incorporated as a subassembly through a powder inlet end of the spray gun into the spray gun and removed from the spray gun upon disassembly of the spray gun housing. Additional embodiments of this concept are presented herein.
    In another embodiment, an element for adding air to a dense phase powder phase may be a filter or other element which has wear over time and is replaceable as part of routine maintenance or repair. The element may optionally be made easily replaceable as part of a removable subassembly without disassembling the exterior structure of the spray gun, for example the spray gun body. With the outer structure, for example, we refer to the embodiments using a spray nozzle, optionally a nozzle nut, a gun body or gun body portion, an extension portion (such as the pipe support below), and a mounting nut end cap, as described hereinafter. The outer structural components will depend on the particular spray gun design, but the replaceable wear part concept refers to the possibility of simply replacing wear parts by releasing a wear subassembly without having to disassemble the basic outer gun body and associated parts. Additional embodiments of this concept are disclosed herein.
    Referring to Figure 1, a prior art automatic spray gun 10 may include a front gun body 12 and a rear gun body 13 housing various components of the spray gun. The embodiments of a pipe support embodiment and a rod support embodiment relate to automatic spray guns as known in the art. We also present an embodiment of a manual spray gun below. The gun bodies 12, 13 may have more sections or parts than needed. The shrouded components may include, for example, a powder flow channel that may be realized as a powder tube 14 that defines a powder flow path P through the spray gun 10 from a powder flow path inlet 16 to a powder flow path outlet 18. The spray gun 10 also typically includes a spray nozzle 20 having a spray outlet 22. Powder flows from the powder flow path outlet 18 into the spray nozzle 20 and then out the spray outlet 22. An example of a spray gun as shown in Fig. 1 is a Model Encore <®> spray gun commercially available from Nordson Corporation, Westlake, Ohio , The prior art spray gun 10 generally uses a powder flow path P which may have a constant inner diameter D1 on the powder tube 14, or more specifically, a constant cross-sectional powder tube from the inlet end 16 to the outlet end 18. This promotes improved flow properties and allows the powder tube cross-sectional area to be formed with the spray nozzle and spray outlet to obtain desired spray patterns. A single-size powder tube also facilitates rinsing and color change.
    The prior art spray gun 10 has been developed to function as a low flow spray gun with a venturi pump. In addition, it is known to provide a spray gun which receives a dense phase powder phase from a dense phase flow pump. There are significant differences between the two spray gun designs due to the properties of the powder flow stream, and therefore the spray gun designs, and in particular the spray nozzles and the powder pipes and hoses for dense stream and thin stream spray guns and coating operations, are different. This results in the need to maintain a parts store for both types of spray guns. The exemplary embodiment of FIG. 1, the Encore <®> spraygun, uses a thin-flow powder phase supplied by a thin-flow pump 24, for example a Venturi powder pump. Accordingly, although not necessary, the powder tube 14 may be a one-piece tube or otherwise have a constant diameter D1 or cross-sectional area from the powder flow path inlet 16 to the powder flow path outlet 18. Because the prior art spray gun 10 is used to spray thin-flow powder phases, a frusto-conical portion 25 of the flow path may be provided at or in the immediate vicinity of the spray nozzle 20. This frusto-conical portion allows the thin-flow powder phase to retard and further atomize to aid in the spray pattern shaping from the spray nozzle 20.
    The spray gun 10 may be considered as having a front portion 26 and a rear portion 28. The front portion 26 includes the spray nozzle 20 and may also optionally include a charging electrode 30 and a high voltage multiplier 32 electrically connected to the electrode 30. In some spray guns, the multiplier 32 may be disposed in the rear portion 28. In Fig. 1, the position of the multiplier 32 is shown schematically.
    Referring to Figure 2, a hybrid spray gun 40 is shown that shares many of the same components with the spray gun 10 of Figure 1, but with several different functions. Parts that may be the same, although they may not be in all cases, are given the same reference numerals as in the embodiment of FIG. 1, but with a prime mark (). Accordingly, the spray gun 40 may include a front portion 26 that is the same or many of the same components as the front portion 26 of the spray gun 10. For example, the front portion 26 of the spray gun 40 may have the same nozzle 20 and the spray outlet 22, FIG same front gun body 12, the same electrode 30 and the same multiplier 32 include. Other internal components of the front portion 26 may also be the same. The powder tube, however, will be slightly different, at least in the back section. In the front portion 26, a first or front powder flow channel is provided, for example, by a first or front powder tube 42 having the same diameter D 1 as the powder tube 14, but the front powder tube 42 is shorter in length than the powder tube 14 because the front powder tube 42 extends only over the front portion 26. In the hybrid spray gun 40, the forward portion 26 may function in the same manner as the forward portion of the prior art spray gun 10 in FIG. 1 and may include similar components. The rear portion 44 may also share many of the same components with the rear portion 28 of the spray gun of FIG. 1, but with additional features and structures as described below.
    In both of the prior art spray gun 10 and the hybrid spray gun 40, the forward section 26, 26 and their respective rearward section 28, 44 may be subdivided by a respective divider wall 34, 46. The partitions are different for both spray guns of Fig. 1 and Fig. 2 for the following reasons given below. But the partitions 34, 46 provide a convenient reference point for identifying the common forward sections 26, 26 and the various rearward sections 28, 44.
    The exemplary hybrid spray gun 40 may utilize a rich powder stream supplied from a dense phase powder pump 48. The hybrid spray gun 40 is unique in that it receives a dense powder flow phase from a dense phase powder pump 48, yet sprays the powder through a thin flow front section 26, particularly the spray nozzle 20, including an expansion chamber and an air diffuser. which are provided within the spray gun 40. For simplicity, the front portion 26 for thin flow may not be the same as the front portion 26 of the spray gun model Encore <®>.
    It should be noted that, when reference is made here to a dense phase pump, here refers to a pump that generates a powder flow having a higher ratio of powder to the flow of air compared to a Dünnstrompumpe, for example, a conventional Venturi-type powder pump. As with the exemplary embodiments, a dense phase powder phase will use a powder hose from a dense phase pump to a spray gun and a powder flow channel within the spray gun having a smaller diameter or cross sectional area than the powder hose and the powder flow channel in the spray gun having a venturi. or other low-flow pump.
    The rear portion 44 includes a second or rear powder flow channel provided, for example, by a second or rear powder tube 50, which may be smaller in diameter D2 and cross-sectional area than the diameter D1 and the cross-sectional area of the single powder tube 14 of FIG 1 and the front powder tube 42. This is because the powder flow from the dense-flow pump 48 has less flow of air. In further accordance with the present teachings, a transition section 52 is provided, optionally as part of the rear section 44, for the smaller diameter D2 or the cross-sectional area of the rear portion of the larger diameter powder tube 50 or the cross-sectional area of the forward section of the powder tube 42 couple. The transition section 52 in the exemplary embodiment includes an expansion chamber 54 that provides a transition region 56 of the powder flow path P between the smaller diameter section P1 of the powder flow path in the rear section 44 and the larger diameter section P2 of the powder flow path in the front section 26. Therefore, in the hybrid spray gun 40, the powder flow path P will include the smaller diameter portion P1, the transition region 56, and the larger diameter portion P2. For simplicity and reference, a longitudinal axis X of the spray gun 40 is indicated, which corresponds to the direction of the powder flow path P, P1 and P2. However, it is not required that in all embodiments and alternative designs the powder flow paths P, P1 or P2 extend only along the single axis X.
    As another optional feature of the present teachings, structures for adding air to the dense powder flow phase, along with the transition section 52 providing an interface between the larger and smaller diameter sections P1 and P2 of the powder flow path P, are provided before the powder flow in the spray nozzle 20 enters. In the exemplary embodiment, an element 58 is provided which allows the air to enter the powder flow path P. In one embodiment, the element 58 may be in the form of an air diffuser made of air-porous material, for example, sintered polyethylene. The air diffuser 58 may be enclosed in the form of a cylindrical body (116, FIG. 5) in a volume which receives compressed air from an air source 59. Optionally, control means (not shown) may be provided to adjust the flow rate of air into the powder stream P so that the air / powder ratio can be controlled to control the flow of powder from a compressed phase to a dilute phase or to another desired air / Powder ratio, which is less dense than the powder flow generated by the pump 48, regardless of whether the desired ratio fits within a definition or understanding of a thin-flow powder phase or not.
    In alternative embodiments, instead of using an air diffuser 58 as described herein, the transition section 52 may provide an expansion chamber structure 54 for the powder flow path transition region 56 in which holes or air jets are provided in the expansion chamber interior 54 to the distributed air to allow to get into the powder stream. Another alternative would be to include an expansion chamber structure 54 in which the expansion chamber 54 comprises an air-porous material. For example, an air-porous element may be disposed within the expansion chamber 54 or just just beyond the forward end (54b, FIG. 4) of the expansion chamber 54. In the present context, the concept of an air diffuser 58 is preferred, as noted in the embodiments herein, but is not essential as this concept supports an embodiment of an easily removable wear subassembly, as taught below.
    Thus, in a basic embodiment of the first inventive concept, a spray gun has a first powder flow path portion adapted to obtain powder coating material having a richer powder / air ratio, for example, a sealant pump. The spray gun also has a second powder flow path portion adapted to direct powder coating material at a diluted powder / air ratio to a spray nozzle which sprays the thin stream powder. The spray gun includes a transition region of the powder flow path coupling the first powder flow path portion to the second powder flow path portion. In an exemplary embodiment, the powder flow path is formed by a first powder tube having a first diameter and a second powder tube having a second diameter greater than the first diameter, the transition region providing an expansion chamber to couple the two differently sized powder tubes. The basic embodiment may optionally include an element for adding air into the powder stream to dilute the richer powder stream.
    Although, as described, the embodiments of Figs. 1 and 2 with respect to the front portions 26, 26 and the rear portions 28, 44 by the respective partitions 34, 36, which represent a convenient reference point, are limited However, a physical separation of the front and rear sections is not necessary. Based on the above description, it can be seen that the identification of the front portion 26 and the rear portion 44 of the hybrid gun 40 is a reference point where the transition region 56 of the powder flow path ends and the larger diameter portion P2 of the powder flow path begins. In the exemplary embodiment, this reference point is the partition 46, but this is not required. The terminology and reference point are useful for understanding the inventive concept described below.
    It is important to note that although one embodiment of a prior art spray gun is shown in Figure 1 and how this gun can be changed to a structure of Figure 2, the same concepts apply to many others Spray gun designs and configurations can be applied. One of the important teachings herein is that a known spray gun configuration operated from a thin-flow powder pump, as may be the case when used with many of the same parts, may be optionally configured, modified, or initially assembled alternatively, to be operated from a dense phase powder pump, but with a low flow spray dispenser. Prior to this disclosure, such modification using a significant number of like components was not known. Therefore, another inventive concept is to disclose in this disclosure an adjustable spray gun that operates in a first selectable configuration with a thin-flow pump. In both selectable versions, the spray gun sprays a diluted or lean stream of powder.
    Figures 1 and 2 comparatively illustrate the inventive concept of a configurable spray gun. A first selectable configuration is the spray gun 10, which receives a thin-flow powder phase and sprays the powder from a spray nozzle as a thin stream, the powder preferably being passed through a constant diameter powder flow path. A second selectable configuration is a spray gun 40 (also referred to herein as a hybrid spray gun) which receives a dense powder flow phase and sprays the powder from a spray nozzle as a thin stream. Both selectable configurations can share a common front section using the same components. One configuration is selected by selecting one of the two trailing sections that share numerous common components, but where one of the selectable trailing sections provides a continuous stream of thin powder flow path and the other selectable trailing section has a transition region of the powder flow path that provides coupling between one Dense flow powder flow path and a thin flow powder flow path. Thus, by using a few different parts, a spray gun can be assembled where, in both of the two selectable and different configurations, most of the parts are the same for both configurations.
    It should be noted that the first and second configurations may be related but individually unique and advantageous. The hybrid spray gun, which receives a dense powder phase and sprays a thin flow powder, can be configured independently of all other spray gun configurations. Although the hybrid spray gun is based on a thin-flow spray gun and the use of equal sections and parts, a configurable spray gun design is enabled.
    Turning now to Figs. 3 and 4, the spray gun 40 is shown in a first embodiment in a pipe mount configuration. The spray gun 40 includes the front portion 26 and the rear portion 44. The front portion includes a front gun body 60 (corresponding to 12 of FIG. 2) and a rear gun body 62. In the exemplary embodiment, the rear gun body 62 corresponds to the transition portion 52 of FIG. 2. A support tube 64 extends rearwardly and has a length that is selected as needed for a particular coating operation. The holding tube 64 may be several feet long in the area of a foot as Längenmaß. The support tube 64 is not necessarily shown to scale the length in FIGS. 3 and 4. A pipe support configuration generally refers to an arrangement in which the spray gun is supported by a gun moving device (not shown), such as a moving unit, an oscillator, or other device used to mount the spray gun in a spray booth for a gun Position coating process. The spray gun 40 is mounted on the gun moving device, for example, by a holder or other gripping mechanism attached to a suitable location of the holding tube 64 (not shown).
    A spray nozzle 66 (which corresponds to the spray nozzle 20 in Fig. 2 and optionally may be the spray nozzle 20 of Fig. 1) is mounted on a front end 60a of the front gun body 60 and includes a spray nozzle outlet 68. The spray outlet 68 can have the shape of a slot or other geometry that produces a desired spray pattern. The spray nozzle 66 is retained on the front gun body 60 by a nozzle nut 70 which may be threadedly engaged with the forward end 60a of the front gun body 60.
    The spray gun 40 has a powder inlet end 72 at the rear end of the spray gun. Powder coating material is supplied from the powder pump 48, such as a dense phase flow pump, to the spray gun 40. A powder hose 74 (Figure 4) connects an outlet of the powder pump 48 to an inlet hose connector 76 at the rear end of the spray gun 40. The inlet hose connector 76 slides on the rear end of a first or rear powder tube 78 (which corresponds to the powder tube 50 in Figure 2). and may be sealed against the outer surface of the rear powder tube 78 with gaskets 80, such as O-rings. The rear powder tube 78 pushes through a clamping tube 82, which acts as a connecting rod. The clamp tube 82 has a first thread 82a and a second thread 82b. The first threaded end 82a mates with a threaded fastener nut 84. The threaded nut 84 includes an inwardly directed lip 86 that engages a flange 88 on the hose connector 76 so that when the nut is tightened on the clamp tube 82, the hose connector 76 is pulled against the rear end 78a of the rear powder tube 78 (As discussed below, the rear powder tube 78 may be part of an assembly that facilitates removal and insertion of an air diffuser by simply unscrewing the retaining nut from the clamp tube 82). The rear end 78a of the rear powder tube 78 corresponds to the powder flow path inlet 16 in FIG. 2.
    The second threaded end 82b of the clamping tube 82 is screwed into a threaded opening at the rear end 62a of the rear gun body 62. The holding tube 64 has a front end 64 a, which abuts against an outer shoulder 62 b of the rear gun body 62. The support tube 64 encloses much of the clamp tube 82, but the trailing end 64b of the support tube 64 abuts the end cap 92 which is held in place on the clamp tube 82 by a threaded nut nut 94. Therefore, when the clamp tube 82 is attracted to the rear end 62a of the rear gun body 62, the holding tube 64 is axially held in compression against the rear gun body 62.
    Referring to FIGS. 4, 6 and 7, a partition wall 96 is disposed at the rear end of the front gun body 60. The partition wall 96 covers the open rear end of the front gun body 60. The partition wall 96 includes a front flange 98 which is inserted in a partition wall recess 100 in the front gun body 60 and at the top against the rear end of the multiplier 32. The front flange 98 is received when the rear gun body 62 is attached to the front gun body 60. The partition 96 may be a molded plastic part that provides the expansion chamber 54. The expansion chamber provides a transitional area of the powder flow path P, as described with reference to FIG. 2, and more particularly, the expansion chamber 54 has a rear end diameter or cross-sectional area 54a that preferably matches the diameter of the rear powder tube 78 and a front end diameter or Cross-sectional area 54b, which preferably with the diameter with the front powder tube end 102 fits (the front powder tube 102 corresponds to the powder tube 42 in Fig. 2). The front powder tube 102 has a rear end 102a (FIG. 8) and a front end 102b (FIG. 10). The front end 102b corresponds to the powder flow path outlet 18 in FIG. 2.
    It should be noted that the expansion chamber 54 could alternatively be provided in a separate element or sleeve, which is rather coupled to the partition wall 96 as integrated into the partition wall 96. It should also be noted that the rear gun body 62, together with the divider 96 and the air diffuser 58 (also described below at 116), correspond to the transition portion 52 of FIG.
    The front end of the partition wall 96 includes a first recess portion 104 (Fig. 7). The rear end 102a of the front powder tube 102 is inserted into the first recess portion 104, and a sealing collar 106 (FIG. 8) may be used between the front powder tube 102 and the first recess portion 104. During assembly, the front powder tube 102 is preferably inserted from the front end of the spray gun 40 before the spray nozzle 66 is mounted, but after the partition wall 96 has been secured against the front gun body 60, and seated in the first recess portion 104. The front powder tube 102 is inserted in the first recess portion 104 until the rear end 102a of the front powder tube 102 abuts against the shoulder 104a (Fig. 7). The front powder tube 102 is inserted into the first recess portion 104 of the partition wall 96 and below against the shoulder 104 a so that the rear end 102 a of the front powder tube 102 has a smooth and preferably seamless interface with the front end 54 b of the expansion chamber 54. Preferably, the forward end 54b of the expansion chamber has an inner diameter or cross-sectional area that matches the inner diameter or cross-sectional area of the powder flow path P2 defined by the front powder tube 102.
    The rear end of the partition wall 96 includes a second recess portion 108 (Fig. 6). A diffuser carrier 110 (see also FIG. 5) is disposed in the rear gun body 62. The diffuser support 110 includes a front smooth-walled recess 112 and a rear threaded recess 114. The rear powder tube 78 may include a threaded forward end 78b threaded into the threaded rear recess 114 of the diffuser support 110, until the front end 78b of the rear powder tube 78 runs against the partition wall 120. The front recess 112 slidably receives the air diffuser 58 (also FIG. 2) so that the rear end of the air diffuser 58 leaks against the partition wall 120. The air diffuser 58 may be a hollow cylinder of porous material that allows the air to be introduced through a porous wall 116 of the air diffuser 58 into the interior 118 of the air diffuser 58. The diffuser support 110 may include a divider 120 having a flow-through hole 122 therethrough such that the powder is passed from the rear powder tube 78 through the air diffuser 58 through the expansion chamber 54 and then through the front powder tube 102. The partition wall 120 serves as a stop for the rear powder tube 78, when it is screwed into the diffuser support 110, and for the air diffuser 58, when it is inserted into the front-side recess 112 of the diffuser support 110.
    The front end 116a (FIG. 8) of the porous wall 116 extends just past the front end of the diffuser support 110. The diffuser support 110 is inserted into the smooth-walled second recess portion 108 of the partition wall 96 so that the front end 116a of the porous Wall 116 runs against a shoulder 108a. The front end 116a of the porous wall 116 may have a smooth and preferably seamless interface with the rear end 54a of the expansion chamber 54. Preferably, but not necessarily, the rear end 54a of the expansion chamber 54, the air diffuser 58, and the hole 122 in the diffuser support 110 have an inner diameter or cross-sectional area that matches the inner diameter D2 or cross-sectional area of the powder flow path P1 defined by the rear powder tube 78. An optional seal 109 may be provided at the forward end 116a of the air diffuser 58 in a reduced diameter extension 116b. This seal 109 can prevent atomized compressed air or distributed air from bypassing the air diffuser 58. The seal 109 may be made of a suitable material, such as a foam gasket.
    As a further alternative, the seal 109 may be sized to have an inner diameter equal to the inner diameter of the porous wall 116 and the diameter of the rear end 54a of the expansion chamber 54. This would provide a seal disposed and compressed between the aft end 54a and the air diffuser 116. In this alternative embodiment, the rear end 54a of the expansion chamber 54, the seal 109, the air diffuser 58 and the hole 122 in the diffuser support 110 will have an inside diameter or cross-sectional area that matches the inside diameter D2 or the cross-sectional area of the powder flow path P1 passing through the rear Powder tube 78 is defined.
    With the spray gun 40, an output of a dense phase powder pump 48 is connectable, wherein the rear powder tube 78 will have a smaller inner diameter than the front powder tube 102. The front powder tube 102 has a larger diameter because the powder stream is diluted with additional air as introduced through the transition section 52 of the spray gun 40 to allow the powder to be sprayed through the spray nozzle 66 which is set to To spray thin stream powder. On the other hand, the expansion chamber 54 defines a transition region 56 of the powder flow path P connecting the smaller diameter powder flow path P <b> 1 in the rear portion 44 to the larger diameter powder flow path P <b> 2 in the front portion 26.
    The partition wall 96 further includes a first opening 124 in the flange 98, through which ducts 126 may be made in the front section 26. The leads 126 are used to connect the multiplier 32 for spray guns utilizing electrostatic powder coating technology to the power supply. The partition wall 96 may include a second opening 128 through which an air tube 130 extends forward to the forward end of the spray gun 40. This air tube 130 supplies pressurized air, which serves as electrode wash air, to keep the electrode tip clean during the coating operations (the electrode assembly is described below).
    Referring to FIG. 8, an annular seal carrier 132 includes a seal groove 134 that holds a diffuser support seal 136, such as an O-ring. A front portion of the diffuser support 110 is inserted through the seal support 132 so that the front end 116a of the porous wall 116 abuts the shoulder 108a of the partition wall 96. The second recess portion 108 of the partition wall 96 provides a sealed chamber 138 to the front portion of the diffuser support 110, which is directed forward to the diffuser support seal 136. An air passage 140 opens the sealed chamber 138. The air passage 140 is formed in a pipe stub 142 which is integral with the partition wall 96. A diffuser air tube extension (174) is connected at one end to the pipe stub 142 and is connected at the opposite end to a diffuser air fitting (172) connected to a source of compressed air (as described below). The diffuser carrier 110 has one or more through holes 144. Pressurized diffuser air, indicated by the arrow 146, enters the sealed chamber 138 from the air passage 140 and continues to flow through the holes 144 as the seal 136 seals against the outer surface of the diffuser support 110. The air diffuser 58 sits with clearance in the front recess 112 of the diffuser support 110, so that it is centered in a front interior 148 of the diffuser support 110, which receives the pressurized diffuser air 146. An interference fit, as at 149a and 149b, may be used to support the porous wall 116 in the center of the diffuser carrier 110. The porous wall 116 penetrates diffuser air, as also shown schematically by the arrows 150, into the powder flow path P1 and mixes with the powder, resulting in dilution of the powder stream. The amount of dilution may be selected based on the amount of diffuser air added to the powder flow path P1, based on the design of the spray nozzle and associated parts at the front end of the spray gun. The added diffuser air may thus be used to dilute the dense powder phase received from the dense phase flow pump 48.
    With reference to Figures 6 and 9, the divider 96 can be secured to the front gun body 60 using threaded bolts 152 and nuts 153 extending from the back of the front gun body 60 (Figure 6) and through the protrusions 154 in the partition 96 extend. This mechanical connection can also be used to couple the electrical ground to the threaded bolt 152 with grounding terminals 125 (see FIG. 9). The rear gun body 62 may be secured to the bulkhead 96 by means of screws 155 (only one is visible in FIG. 9) or other suitable means. The screws 155 may be used to connect a ground plate 156 (also FIG. 4) to the threaded inserts 157 provided in the partition wall 96. The screws 155 thereby connect the rear gun body 62 to the divider 96, and the threaded bolts 152 and nuts 153 secure the front gun body 60 to the divider 96. The assembled spray nozzle 66, the nozzle nut 70, the front gun body 60, the rear gun body 62 and the holding tube 64 are thus held together and form a housing that encompasses most of the spray gun components, and in particular the transition region 56 of the powder flow path.
    Referring again to Figures 4 and 5, the air diffuser 58 may lose its porosity over time due to the powder flowing therethrough. It is noted that the air diffuser is a wearing part that needs to be replaced occasionally. To avoid the disassembly of the spray gun and to achieve the air passage, in accordance with another inventive concept, the rear powder tube 78, the air diffuser 58, and the diffuser carrier 110 are designed as easily detachable air diffuser subassembly 160. The subassembly 160 may optionally be expanded to include the inlet tube connector 76 and the mounting nut 84. 4, it is noted that with the exception of the mounting nut 84, the entire air diffuser subassembly 160 is slidably inserted into the rear gun body 62 by the clamp tube 82 and is secured in the rear end of the divider wall 96 (FIG. 8). By simply loosening the fastening nut free from the threaded end of the clamping tube 82, the entire subassembly 160 can be pulled out of the rear end of the spray gun 40. This provides easy access to the air diffuser 58 for replacement, cleaning or maintenance as needed. After the mounting nut 84 is released, the user can simply pull on the hose connector 76 and pull the subassembly 160 out of the otherwise fully assembled spray gun 40. The fastening nut 84 and hose connector 76 are optionally considered parts of the subassembly 160, in that sense that the subassembly can be removed by pulling the hose connector 76, but only if there is a sufficiently tight connection between the hose connector 76 and the rear Powder tube 78 exists. Otherwise, the mounting nut 84 may be removed and then the rear powder tube 78 grasped and removed from the spray gun body. Preferably, the air diffuser subassembly 160 may be removed without disassembling the outer structure of the spray gun 40, thus, in the exemplary embodiments, various important components such as the spray nozzle 66, the nozzle nut 70, the front and rear gun bodies 60, 62, and the support tube 64 along with Objects such as the clamping tube 82 are meant.
    Referring to Fig. 4, at the back of the spray gun 40 is an electrical connector 162 which receives an input plug 164 which may be connected at its other end to a power supply (not shown). For example, the input plug 164 may include three wires for a 21 VDC supply that is used to supply the multiplier 32 and a current feedback signal line. The electrical power provided to the spray gun is coupled to the multiplier 32 via the multiplier input lines 126 as part of a cable routed through the rear portion 44 to the input connector 164. However, the inventions described herein may also find application to non-electrostatic spray guns and coating operations.
    Referring to Figs. 4 and 9, a diffuser air port 166 is provided at the rear end of the spray gun 40 which can be connected to a source of pressurized diffuser air 168. The diffuser air port 166 is connected to a first end of a diffuser air tube 170 which is connected at its other end to a first connector end 172a from a diffuser air port 172 having a ground plate (FIG. 9). A diffuser air tube extension 174, such as a pipe coil, connects the pipe stub 142 to a second terminal end 172b from a diffuser air port 172 having a ground plate (see FIGS. 6 and 7). In this way, the diffuser air 146 is directed to an air diffuser 58 from the air source 168. It should be appreciated that the air source 168 may optionally be controlled, such as electronically or manually, to provide a selectable amount of air to the spray gun 40, such that the amount of diffuser air added to the powder stream is adjusted for particular adjustments and coating operations as needed can be.
    Although the air diffuser is shown as being positioned relatively close to the expansion chamber 54, this is not required. The diffuser air can be added to the powder flow at any point even before entering the spray gun 40. However, it has been found that adding the diffuser air approximately to the spray nozzle 20, but at a distance such that there is sufficient time for the diffuser air to dilute the powder flow in an enlarged powder flow path P2 (FIG. 2), thereby providing better spray patterns various applications can be achieved. Therefore, in the exemplary embodiments, the air diffuser is shown near the entrance of the expansion chamber 54. The location of the expansion chamber 54 is also a matter of design within the spray gun 40. However, axial separation (for example, relative to the longitudinal axis X of the powder flow path P1, P2 through the spray gun) has been found to provide more between the expansion chamber and the spray nozzle 20. *** " Time for the powder flow is provided to be diluted and form an efficient flow pattern for spraying from the spray nozzle 20.
    Although not shown in detail in the drawings, an electrode-washing air connection may be provided at the rear end of the spray nozzle 40. This electrode wash air port receives compressed air from a compressed air supply and through a second air port in the ground plate 156. The electrode wash air port is connected to the electrode wash air tube 130 (Figures 4, 6 and 7) extending to the front end of the spray gun 40 extends.
    Referring next to Figs. 3, 10 and 11, the front portion 26 will be described next. With the exception of the divider components 96, but need not, the front portion 26 may be the same as the corresponding parts of the Encore <®> spray gun as mentioned above. Therefore, a detailed description is not necessary to understand and practice the inventions in the present disclosure as illustrated. Prior art Figs. 10 and 11 are not labeled because the front portion 26 is shown in combination with the rear portion 44 which receives a dense powder phase. The front portion 26 may also be the same for the pipe support configuration or a rod support configuration, as described below, or may be another mounting configuration as desired. However, the use of the same front portion 26 can significantly reduce part inventory and assembly times for different spray guns that can be configured in different ways, such as a spray gun powered by a thin-flow powder pump (such as a Venturi pump) Dense phase powder pump, or spray guns used with various mount configurations or as manual or automatic spray guns.
    The front portion 26 includes an electrode support assembly 180. The electrode support assembly includes an electrode holder 182 having an electrode 184 disposed within a passage 182a on the electrode holder 182. An electrode tip 184a extends outside of the electrode holder 182. The electrode holder 182 has a first end received in a mandrel holder 186. The electrode 184 has a coiled end 188 that extends into a blind bore 190 of the mandrel holder 186. Two inclined channels 192, 194 are provided in the mandrel holder 186 and extend outwardly through a flange 198. In one of the oblique channels 192, a current limiting resistor 200 is disposed and has a first lead 202 extending downwardly about the coiled end 188 of the electrode to connect. A second line 204 of the resistor 200 connects a conductive ring 206, which is held on the back of the flange 198. The multiplier 32 is connected to an output pin 208 which is in contact with the conductive ring 206. In this way, high voltage electrical energy is electrically connected to the electrode 184 by the multiplier. As best shown in FIG. 11, the mandrel holder 186 includes flow channels 210 that allow the powder to flow through the mandrel holder 186 and into the spray nozzle 66.
    At this point, some differences between a thin-flow spray nozzle and a dense-stream spray nozzle are useful for understanding. In a powder spray gun supplied from a Venturi or other thin-flow powder pump, for example the Model Encore <®> spray gun as described herein, the spray nozzle is configured to apply a desired spray pattern through a slot or other spray outlet to provide the spray nozzle. The powder flow in the spray nozzle tends to have a high velocity and a large volume of air flow, resulting in a low powder / air ratio or a lean mixture. The spray nozzle is then not added to flow air or dilution air since the powder flow is already diluted. The spray nozzle tends to slow the velocity of the powder stream as it exits the powder tube and then form a desired spray pattern, often like a cloud of powder coating material. Typically, the electrode tip is placed inside the spray nozzle. In a dense phase spray gun, the powder tube may provide the spray outlet because the dense phase powder phase may appear as a liquid or flow-like flow. In this case, the dense stream spray nozzle would comprise a compressed air source to form the spray pattern only from the spray nozzle, with the electrode tip also being located outside the spray nozzle. In other instances, a dense stream spray nozzle may include a source of flow air in the nozzle to dilute the spray powder prior to exiting the spray nozzle. Accordingly, dense stream spray nozzles may be more complex to form or display additional components of parts of different spray guns. With the present inventions, the simpler, low-flow spray nozzle can be used in a spray gun even if the spray gun is powered by a pump which produces a powder flow having a higher density than that produced by a thin-flow pump or Venturi pump , The spray nozzle 20, 66, as noted in the exemplary embodiments of the hybrid spray gun 40, may therefore be a low-flow spray nozzle, such as the spray nozzle relating to the Encore <®>, or other dense flow spray nozzle. When the front section 26, 26 is used for a thin stream of a hybrid spray nozzle 40, significant savings are possible in terms of a reduced inventory of specialized parts otherwise required for a dense phase spray gun using a front section for dense flow. This also facilitates the use of an adjustable spray gun as discussed herein.
    The mandrel holder 186 may have a tapered channel 212 (corresponding to the frusto-conical path portion 25 in FIG. 2) between the end of the front powder tube 102. This tapered channel 212 has a frusto-conical shape and is used in a thin-flow spray gun to allow the high flow powder flow to dissipate some energy prior to entering the spray nozzle 66 and to further disperse, allowing the powder to be electrostatically charged more efficiently , However, the channel 212 tapering in the mandrel holder can not be used in place of the expansion chamber 54, because the dense powder phase that would enter the mandrel holder 186, even if the diffuser air were added, would travel too short a distance to dilute Distribute phase for spraying with a thin-flow nozzle.
    The electrode washing air tube 130 is connected to an air washing port 214, which is opened to the space behind the flange 198. This electrode washing air is introduced through the second inclined channel 194 and into the blind hole 190. The electrode washing air then flows around the electrode 184 through the annular space between the electrode 184 and the inner diameter of the passage 182a in the electrode holder 182.
    The front powder tube 102 is positioned and held adjacent to the mandrel holder 186 by a holding seal member 216. The mandrel holder 186 is fixed between the spray nozzle 66 and the front end of the front gun body 60 when the nozzle nut 70 is tightened on the front gun body 60. This also applies to an axial load against the front powder tube 102 to ensure that it is fully seated in the forward portion of the divider wall 96, as described above, and secures the mandrel holder 186 in the retention seal 216.
    Referring to Figure 12, an embodiment of the hybrid spray gun 220 in a stick support embodiment is illustrated. Many of the components for the rod support configuration may be the same as those used for the tube support configuration, and their description will not be repeated. Like reference numerals are used for the same parts. The rod support configuration does not utilize the extended length of the tube support configuration as described hereinabove. In one embodiment, the spray gun 40 may include a front portion 26, which may be the same but need not, like the front portion 26 of the pipe support configuration. Accordingly, the description of this part of the spray gun 220 need not be repeated. The spray gun 220 has a rear portion 222 which also has many of the same components as the above embodiment. But as already mentioned, the rear portion 222 does not include the pipe support extension. However, the divider 96 may be the same as the diffuser carrier 110, the air diffuser 58, the rear gun body 62, and the seal carrier 132 may be the same. A clamp tube 224 is also used for the same purpose as in the tube support configuration, except that it may be shorter in length. A rear powder tube 226 is similarly connected to the diffuser carrier 110, but may also be comparatively shorter in length. The clamp tube 224 cooperates with a mounting nut 84 and an inlet tube connector 76.
    The rod support configuration includes a fastener 228 that supports a rod support configuration 230. The rod support configuration may also include an electrical input and a diffuser air inlet, as in the tube support configuration. Accordingly, the rod support configuration and the tube support design share many similar components, with most of the internal components being the same. The rear portion 222 shares many common components, particularly those within the rear gun body 62. The major differences between the pipe support and rod support configurations are the rod support assembly 230, the mounting portion 228, and the shorter powder tube 226 and clamp tube 224. The hose connector 76 can be connected to receive a powder flow from a sealant pump, although the spray gun 220 will spray powder in a thin stream.
    The rear powder tube 226 and the diffuser carrier 110 and the air diffuser 58 also form a subassembly 160 (Figure 5) that can be easily removed from the spray gun 220 without disassembling the spray gun. The subassembly 160 may be removed by simply loosening the mounting nut 84 and pulling out the subassembly at the rear end of the spraygun 220.
    With reference to Figs. 13 and 14, the configurable gun concept may also be employed herein with a handheld spray gun. For example, an exemplary hand-held spray gun 240 is presented, which may, but need not, be substantially the same as the Encore®® hand-held spray gun available from Nordson Corporation, Westlake, Ohio. This spray gun is also fully described in U.S. Patent Application Publication No. US 2009/0107397, published April 30, 2009 to Mather et al. DEVICE AND METHOD FOR RINSEING MATERIAL APPLICATION DEVICES, the entire disclosure of which is hereby incorporated by reference. This hand-held spray gun is designed to spray low-flow powder. However, in accordance with other concepts of the present invention, another hose connector is used so that the spray gun can be connected and used with a powder flow from a dense flow powder pump 48 (Figure 13).
    In one embodiment, a hose connector 242 is included at the rear end of the powder tube 244 which extends into a handle 246 and to the main gun body or barrel 245. As best shown in FIG. 14, the tubing connector 242 includes a tubing connector mandrel 248 to which a powder feed tubing 412 may be attached that supplies powder from the dense flow pump 48. The hose connector 242 may also include a transition section 249 having an expansion chamber 250 therein. The expansion chamber 250 has a first end 252 that has a diameter or cross-sectional area that preferably matches the diameter D 2 or the cross-sectional area of the flow path 254 through the hose mandrel 248. The expansion chamber 250 has a second end 256 with a diameter or cross-sectional area that preferably matches the diameter D1 or the cross-sectional area of the powder tube 244. The dimensions D1 and D2 may, but need not, be the same as the dimensions of D1 and D2 in the embodiment of FIG. 2. The expansion chamber 250 thus provides a transition region 258 of a powder flow path P having a smaller diameter portion P1 and a larger diameter portion P2 in the powder tube 244. The smaller diameter portion P1 may be used when the spray gun is connected to a dense phase powder pump. The larger diameter portion P2 may be the same as commonly used when the spray gun 240 is used to spray a thin flow powder.
    As described in said published patent application, the spray gun 240 may include a scavenging air inlet 260 and an electrical connection 261. Purge air enters and passes through a passage 262 which communicates through holes 264 with an annulus 266 surrounding a front portion 268 of the hose connector 242. The purge air flows up into the powder tube 244 to purge the spray gun 240. In accordance with the teachings herein, the scavenging air inlet 260 may be used to provide diffuser air into the powder flow path P2 during a non-cleaning operation, for example, during a coating operation. The diffuser air may be used to dilute the dense powder phase received by the dense-flow powder pump 48 so that the spray gun 240 can continue to be used to spray powder in a thin stream. It should be noted that in the manual version of FIG. 13, the diffuser air flows into the front powder flow path or downstream of the expansion chamber 250, while in the automatic spray gun configuration described hereinabove (the pipe support and rod support configuration), the diffuser air flows into the powder stream before it enters the expansion chamber 54. The manual spray gun 214 may also include a spray orifice 302, a spray nozzle 304, a front powder tube 306 (which preferably but not necessarily has the same diameter D2 as the powder tube 244), and an electrode 308. The front-end portion of the spray gun 245 may include a mandrel holder 310 and a nozzle nut 312, which may or may not include the same as the corresponding parts in the automatic gun design herein.
    Note that, compared to FIG. 2, the powder flow path inlet 16 is provided by the powder path hose nozzle 254, the powder flow path outlet 18 is provided by the outlet end 306a of the front powder tube 306, the transition section 52 is provided by the transition section 249, and so forth Element 58 is provided for adding diffuser air through the purge air flow path within annulus 266.
    It should also be noted that the use of a scavenging air inlet 260 to provide diffuser air during the coating process (which occurs with the flow of powder through the spray gun 240) also allows the same air inlet 260 to be used to supply purge air during a scavenging operation (when powder does not flow through the spray gun 240). Rinsing can, as is known, be carried out as part of a cleaning process or a color change process.
    The manually operable spray gun 240 may therefore be configured as a thin-flow powder spray gun powered by a thin-flow pump as conventionally designed and used. Alternatively, by altering a portion of the inlet hose connector 242 on the one hand, the manually operable spray gun 240 may be reconfigured as a manual hybrid spray gun to be supplied with a dense powder phase from a dense phase flow pump 48 which still sprays a thin stream powder spray pattern. In this hybrid handgun, the air inlet 216 may be used to supply dilution air during the coating process and purge air during the cleaning or color changing operation. Different air flow rates for rinsing and diluting may be used as needed.
    With reference to Figure 15, a rod support version of a thin-flow spray gun is illustrated, for example the Encore <®> model as mentioned hereinabove. The spray gun 270 may include a front portion 26 having the same parts as the front portion 26 in the hybrid spray gun 220 embodiment as explained in FIG. 12. A rear portion 272 includes a rod support assembly 274, which may be the same as the hybrid spray gun 220 including the retention member 276. The rear gun body 278 may be connected to a bulkhead 280, which may also be attached to the front gun body 282 in a similar manner as connected in the above embodiments. A powder tube 284 may be a unitary powder tube that extends through the housing of the spray gun 270 and is received in the mandrel holder 186 (FIG. 10). Since the spray gun 270 is designed to spray diluted powder phases, the powder tube 284 may be equipped with a larger diameter, as is known. A comparison of Figures 12 and 15 shows the configurable spray gun concepts presented in the disclosure. Using the same front portion 26, significant savings and efficiency in providing two selectable spray gun configurations are possible, namely a spray gun 270 designed to spray a thin stream received from a thin-flow powder pump. such as a venturi pump. However, by selecting some basic parts that are different, a hybrid spray gun 220 is provided which can spray a thin-flow powder although the powder source is a dense flow powder pump. To build the hybrid spray gun 220, the divider 96 is to be used in place of the divider 280, the single powder tube 284 is replaced by the front powder tube 102 and the rear powder tube 226, and the rear gun body 62 is instead of the rear gun body 278 use. The various rear gun body 62 results from the use of the various divider wall 96, which is longer than the divider wall 280, because of the inclusion of the expansion chamber 54. The rear gun body 62 also includes a threaded rear end which mates with the clamp tube 224 ,
    It is noted at this time that the exemplary embodiments herein illustrate the components that are of a selected shape and size as needed for a particular spray gun design. However, in terms of providing a basic spray gun design, which may be selectively configured to operate with a thin-flow or dense-stream spray gun, the choice of which parts may be the same and which parts are replaced is essentially one Selection of design choices based on overall spray gun functionality. The basic lesson for a configurable spray gun concept presented herein is the transition section 52 (Figure 2), which includes the expansion chamber 54 and the optional element or air diffuser 58 along with the concomitant use of a front powder tube and a rear powder tube having different diameters from each other such that the first selectable spray gun configuration allows the spray gun to be used with a thin-flow powder pump (e.g., FIG. 15) and a second selectable spray gun configuration allows the spray gun to be used herein also referred to as a hybrid spray gun, is used with a dense phase powder pump (e.g., FIG. 12) during the spraying of thin flow powder.
    A similar analysis may be applied to the pipe support embodiment of FIG. 4. FIG. 16 shows a tube support configuration for the traditional Encore® spray gun 290. The spray gun 290 uses a one-piece powder tube 292, the general front portion 26, the extension of the mounting tube 294, the terminal block 296, and a rear gun body 298 Part of a rear section 300. A comparison with the hybrid spray gun 40 of Figure 4 shows that in the hybrid configuration, a front powder tube 102 and a rear powder tube 78 with a different partition 96 are used compared to the conventional spray gun design 290, which uses the integral powder tube 292. In addition, the rear gun bodies 298, 62 may also be different because of the exemplary size and shape of the divider 96 used in the hybrid spray gun, which in itself is not necessarily required, just as in the rod support embodiment.
    Reference is also made in the above disclosure to a dense phase powder pump 48 which is also well known as a high pressure powder pump. Many different dense-flow pumps are commercially available, and one such pump is described in US Pat. No. 7,997,878, issued August 16, 2011, by Terrence M. Fulkerson for INDUCED FLOW AND FLUSH SEALING CIRCULAR POWDER PUMPS; and U.S. Patent US 7,150,585, issued December 19, 2006 to Kleineidam et al. for methods and devices for the transport of powder material; the entire disclosures are fully incorporated herein by reference. Referring to FIG. 17, an exemplary dense phase flow pump 400 may utilize at least one or more pump chambers 402 in the form of a hollow cylinder 404 formed of an air porous material 406. The material 406 for the pumping chambers 402 may, but need not, be similar to the air diffuser 58 which, as described herein, is, for example, sintered polyethylene. Each pumping chamber 402 is disposed in a pressure chamber 408 so that powder is drawn into a pumping chamber volume 410 from a powder supply 411 through a supply tube 412 when a vacuum is applied from a vacuum source 414 to the pressure chamber 408 and powder from the pumping chamber 408 to a supply tube 418 is pushed out when an overpressure from a pressure source 416 is applied to the pressure chamber volume 410. The control of the powder into and out of the pump chambers may be performed with powder flow control valves, for example, respective pneumatic squeeze valves 420 (powder in) and 422 (powder out), which open and close out of phase with each other, as is known. Pressure control valves, such as vacuum control valves 424, and pressure control valves 426 may also be used to control the timing when positive and negative pressure cycles occur. The low flow air for dense phase powder phases results from the use of pressure to move the powder, as opposed to the high air velocities used in a thin flow powder pump, such as a Venturi pump. Various dense flow powder pump designs can produce powder streams that vary in powder / air ratio or, in other words, vary in how rich the powder flow in the spray gun is, and similarly, different venturi pump designs can produce different levels of lean powder streams. For this reason, there is no limitation of the disclosure herein to a definition of what is a dense stream versus a thin stream. However, in a dense phase powder phase, smaller diameter or cross-sectional powder flow paths are typically used, compared to a thin flow powder flow path, due to the lower flow air amount in the powder stream. The schematic representation of FIG. 17 shows an embodiment of the inventive concept of a hybrid spray gun 40, which uses a dense phase powder phase in the spray gun and sprays the powder in a front end thin stream.
    权利要求:
    Claims (16)
    [1]
    A spray gun (40) that may be selectively configured to operate with a venturi pump (24) or a dense phase flow pump (48), comprising:a gun body (12, 13; 12, 13) having a front portion (26, 26) and a selectable rear portion (28, 44),the front portion (26, 26) comprising a spray nozzle (20, 20),a powder flow path (P, P1, P2) extending through the front portion (26, 26) and the selectable rear portion (28, 33) having an inlet end (16, 16) and an outlet end (18, 18) powder coating material being able to flow from the inlet end (16, 16) to the outlet end (18, 18) and from the outlet end to the spray nozzle (20, 20),the front portion (26, 26) being connected to one of two selectable rear portions (28, 44),wherein the first selectable rear portion (28) is configured to operate with the venturi pump (24) and includes a portion of the powder flow path (P), and wherein the powder flow path (P) has a constant cross-sectional area (D1) from the powder flow path inlet end (D1). 16) to the powder flow path outlet end (18),wherein the second selectable rear portion (44) is configured for operation with the dense phase flow pump (48) and includes a portion of the powder flow path (P, P1, P2), and wherein this portion of the powder flow path (P, P1, P2) has a first cross sectional area on the entrance (D2) and output side has a second cross-sectional area (D1) with a transition region (56) of the powder flow path (P, P1, P2) connecting the first cross-sectional area (D2) and the second cross-sectional area (D1), wherein the first cross-sectional area (D2 ) is smaller than the second cross-sectional area (D1).
    [2]
    A spray gun according to claim 1, characterized in that the second selectable rear portion (44) supports a powder tube (50) adapted to receive powder coating material from a dense phase pump (48).
    [3]
    A spray gun according to claim 2, wherein the transition region (56) is contained in a transition section (52) of the second rear selectable section (44), the transition section (52) comprising an element (58) for adding air to the powder coating material, which flows into the second cross-sectional area (D1).
    [4]
    A spray gun according to any one of claims 1 to 3, wherein the transition region (56) is provided in an expansion chamber (54) contained in a transition section (52) of the second rear selectable section (44).
    [5]
    5. A system for coating articles with a powder coating material, the system comprising:A spray gun (10, 40) according to any one of claims 1 to 4, wherein the spray gun (10, 40) is connected to a venturi pump (24) or to a dense phase pump (48), the front portion (26, 26 ) of the spray gun (10, 40) is connected to the first rear portion (28) of the spray gun (10, 40) if the spray gun (10, 40) is connected to the venturi pump (24), and wherein the front portion (26, 26) of the spray gun (10, 40) to the second rear portion (44) of the spray gun (10, 40) is connected, if the spray gun (10, 40) is connected to the sealing flow pump (48).
    [6]
    The system of claim 5, wherein the spray gun (10, 40) is connected to a dense phase pump (48, 400) having a pump chamber (402) in the form of a hollow cylinder (404) made of an air porous material (406) ) is made.
    [7]
    The system of claim 6, wherein the pump chamber (402) is disposed in a pressure chamber (408), and wherein the dense phase pump (48, 400) is configured to draw powder into a pumping chamber volume (410) from a powder supply (411) becomes when a vacuum from the vacuum source (414) is applied to the pressure chamber (408) and powder is forced out of the pump chamber (408) when an overpressure from a pressure source (416) is applied to the pressure chamber volume (410).
    [8]
    8. The system of claim 7, wherein the dense-flow pump (48, 400) is configured to perform control of the powder into and out of the pump chamber (402) with multiple powder flow valves.
    [9]
    The system of claim 8, wherein the plurality of powder flow valves include a first pinch valve (420) through which powder can be drawn into the pumping chamber (402) when the first pinch valve (420) is open and a vacuum is applied to the pressure chamber (408) and a second pinch valve (422) through which powder can be forced out of the pumping chamber (402) when the second pinch valve (422) is opened and an overpressure is applied to the pressure chamber (408).
    [10]
    The system of any one of claims 5 to 9, wherein the spray gun (10, 40) is mounted on a support structure that can move the spray gun (10, 40) to a position for a coating operation, and wherein the spray gun operation is electronically controlled.
    [11]
    11. Use of a spray gun (10, 40) according to one of claims 1 to 4, comprising: in a first step, providing the spray gun (10, 40), in a second step, connecting the spray gun (10, 40) with a pump (24, 48) for supplying a powder coating material, and in a third step, supplying powder coating material with the pump (24, 48) to the spray gun (10, 40) for coating articles with a powder coating material.
    [12]
    Use according to claim 11, wherein the pump (24, 48) is a venturi pump (24), and wherein in the first step a spray gun (10, 40) is provided which connects to the first rear selectable section (28) is.
    [13]
    Use according to claim 11, wherein the pump (24, 48) is a sealing-flow pump (48, 400) having a pumping chamber (402) in the form of a hollow cylinder (404) made of an air-porous material (406) and in the first step, providing a spray gun (10, 40) connected to the second rear selectable section (44).
    [14]
    14. Use according to claim 13, wherein the pump chamber (402) in a pressure chamber (408) is arranged, and wherein powder is drawn into a pumping chamber volume (410) from a powder supply (411) when at the pressure chamber (408), a negative pressure of a vacuum source (414) is applied, and powder is forced out of the pumping chamber (408) when an overpressure from a pressure source (416) is applied to the pressure chamber volume (410).
    [15]
    15. Use according to claim 14, wherein the control of the powder in and out of the pump chamber (402) is performed with a plurality of powder flow valves.
    [16]
    The use of claim 15, wherein the plurality of powder flow valves include a first pinch valve (420) through which powder can be drawn into the pumping chamber (402) when the first pinch valve (420) is open and a vacuum is applied to the pressure chamber (408) and a second pinch valve (422) through which powder can be forced out of the pumping chamber (402) when the second pinch valve (422) is opened and an overpressure is applied to the pressure chamber (408).
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    同族专利:
    公开号 | 公开日
    US20180311688A1|2018-11-01|
    JP2015517904A|2015-06-25|
    DE202013011934U1|2014-11-27|
    US10040081B2|2018-08-07|
    EP2836307A1|2015-02-18|
    US20150053797A1|2015-02-26|
    WO2013154702A1|2013-10-17|
    CN104271252A|2015-01-07|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US2759764A|1954-05-24|1956-08-21|Ransburg Electro Coating Corp|Liquid feeding apparatus|
    US4110486A|1975-01-16|1978-08-29|Adrien Lacchia|Electrostatic powder coating method|
    US4715535A|1986-04-28|1987-12-29|Nordson Corporation|Powder spray gun|
    EP0627265B1|1993-06-02|1998-01-21|Matsuo Sangyo Co., Ltd.|Frictional electrification gun|
    US5395046A|1993-10-25|1995-03-07|Nordson Corporation|Hand-held spray gun with replaceable handle|
    JPH0889853A|1994-07-29|1996-04-09|Nissan Motor Co Ltd|Corona discharge method and electrostatic coating apparatus|
    US5711489A|1994-08-18|1998-01-27|Nihon Parkerizing Co., Ltd.|Electrostatic powder coating method and apparatus|
    US6056215A|1995-03-15|2000-05-02|Nordson Corporation|Electrostatic rotary atomizing spray device|
    AU5782896A|1996-04-04|1997-10-29|Nordson Corporation|Tribo-electric powder spray coating using conical spray|
    FR2750897B1|1996-07-10|1998-09-18|Sames Sa|TRIBOELECTRIC PROJECTOR, COATING PRODUCT PROJECTION INSTALLATION AND METHOD FOR CONTROLLING SUCH A PROJECTOR|
    JP2004502532A|2000-07-11|2004-01-29|ノードソン　コーポレーション|A monopolar powder coating mechanism including an improved triboelectric corona gun|
    US6645300B2|2000-07-11|2003-11-11|Nordson Corporation|Unipolarity powder coating systems including improved tribocharging and corona guns|
    US20030038193A1|2000-07-11|2003-02-27|Rehman William R.|Unipolarity powder coating systems including improved tribocharging and corona guns|
    FR2820344B1|2001-02-08|2003-03-14|Eisenmann France Sarl|TRIBOELECTRIC SPRAYER|
    US20040159282A1|2002-05-06|2004-08-19|Sanner Michael R|Unipolarity powder coating systems including improved tribocharging and corona guns|
    US20030160105A1|2002-02-22|2003-08-28|Kelly Arnold J.|Methods and apparatus for dispersing a conductive fluent material|
    US6874712B2|2002-09-27|2005-04-05|Abb Inc.|Swirl gun for powder particles|
    EP2279796B1|2002-10-14|2020-12-30|H. Börger & Co. GmbH|Method and device for conveying powder material|
    US6971785B2|2003-07-16|2005-12-06|General Motors Corporation|Canister assembly for powder delivery system|
    US7793869B2|2003-08-18|2010-09-14|Nordson Corporation|Particulate material applicator and pump|
    CA2534254A1|2003-08-18|2005-03-03|Nordson Corporation|Spray applicator for particulate material|
    US20050158187A1|2003-11-24|2005-07-21|Nordson Corporation|Dense phase pump for dry particulate material|
    US7757973B2|2005-04-04|2010-07-20|Illinois Tool Works Inc.|Hand-held coating dispensing device|
    US20080205189A1|2007-02-27|2008-08-28|Illinois Tool Works Inc.|Dense phase pump for pulverulent material|
    DE102007046806A1|2007-09-29|2009-04-02|Itw Gema Gmbh|Powder spray coating device and powder conveying device therefor|
    US8726831B2|2007-10-31|2014-05-20|Nordson Corporation|Apparatus and methods for purging material application device|
    US20120038346A1|2010-08-16|2012-02-16|Nordson Corporation|Powder flow monitoring using grounded hoses|DE102013205362A1|2013-03-26|2014-10-02|Gema Switzerland Gmbh|Spray coating gun for spray coating objects with coating powder|
    WO2014161717A1|2013-04-03|2014-10-09|Gema Switzerland Gmbh|Powder conveyor and associated operating method|
    US10150124B2|2014-04-07|2018-12-11|Nordson Corporation|Feed center for dense phase system|
    CN107262320A|2017-06-26|2017-10-20|中信戴卡股份有限公司|A kind of clear powder rifle of automatic powder-cleaning system of swinging cross formula hub stud holes and combined type|
    DE102019125162B3|2019-09-18|2021-03-04|Bader Pulverbeschichtung Gmbh|Device and spray booth for powder coating by means of triboelectric charging|
    法律状态:
    2017-09-29| PCAR| Change of the address of the representative|Free format text: NEW ADDRESS: BELLERIVESTRASSE 203 POSTFACH, 8034 ZUERICH (CH) |
    优先权:
    申请号 | 申请日 | 专利标题
    US201261623870P| true| 2012-04-13|2012-04-13|
    PCT/US2013/029607|WO2013154702A1|2012-04-13|2013-03-07|Powder gun configurable for supply from venturi or dense phase pump|
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