Nozzle assembly

Abstract: A nozzle assembly 12 having shroud members 26, 28 which selectively emit a material 21 along at least one edge of emitted material 25. The selectively emitted material 21 substantially prevents and/or eliminates the turbulent shear layer which is formed within the emitted material 25.

Description: This invention relates to a nozzle assembly and more particularly, to a nozzle assembly which selectively emits material and which substantially prevents and/or which substantially reduces the amount of turbulence occurring within certain portions of the emitted material, thereby allowing the emitted material to be selectively deposited upon a surface and/or upon a targeted location in a desired manner. Nozzle assemblies selectively emit various types of materials, such as and without limitation paint, thereby allowing the selectively emitted material to be placed or deposited upon various objects and/or upon one or more "targeted locations" in some desired pattern and/or concentration. It is oftentimes desirable to cause the deposited material to form or include substantially "well-defined", substantially straight, "crisp", and/or "clean" edges or borders in order to allow the deposited material to create an overall aesthetically pleasing appearance and/or to substantially ensure that only the targeted location(s) or object(s) actually receive the emitted material. For example, vehicle paint striping should normally have relatively well-defined and relatively straight edges in order to properly enhance the overall appearance of the vehicle. While prior nozzle assemblies selectively emit material and allow the selectively emitted material to be placed upon various objects and/or targeted locations, they do not readily provide such well-defined or substantially straight edges due to the creation and/or existence of a relatively turbulent "shear layer" of material which typically occurs at and/or along the edges and/or at and/or along the extremities of the emitted material, and which is typically formed by the entrainment of ambient air into the edge and/or boundary/extremity portions of the emitted material. Nozzles currently exist which provide a shroud layer such as that disclosed in US-A-2 410 532. the shroud layer is a cone of compressed gas which extends beyond the spray pattern of the paint emitted from the nozzle in order to prevent paint spatter. This arrangement can worsen the symptoms displayed by the existence of a shear layer, in that stray paint spattering can bounce off the shroud layer into an area beyond the that defined by the expected spray pattern. This effect has been combated in US-A-2 029 337 which arranges for the shroud layer and paint mixture to exit the nozzle at substantially the same velocity and thus reduce sheer layer formation. This patent teaches a one piece construction, which is undesirable when switching paint colours. According to the present invention a spray nozzle is provided for spraying a first material, comprising a mixture nozzle portion for forming a spray pattern containing the first material, and a shroud nozzle portion for forming a shrouding spray pattern containing a second material which shrouds at least part of the mixture spray pattern, the shroud nozzle portion being arranged relative to the mixture nozzle portion so that the shrouding spray pattern borders and flows alongside the mixture spray pattern to prevent the formation of a shear layer on the outer edge of the mixture spray pattern, characterised in that said mixture nozzle portion includes first and second channels and wherein said shroud nozzle portion is substantially "C"-shaped and includes a first flange portion which removably resides within said first channel and a second flange portion which removably resides within said second channel. The present invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a material emitter which incorporates a nozzle assembly, as taught in accordance with the present invention; Figure 2 is a sectional side view of the material emitter of Figure 1 which is taken along view line 2-2; Figure 3 is a fragmented perspective view of the material emitter which is shown in Figure 1 and which illustrates the selective placement of the shroud portion of the nozzle assembly upon and/or within the material emitter in accordance with the teachings of the present invention; Figure 4 is a fragmented perspective view of the material emitter which is shown in Figure; Figure 5 is a fragmented perspective view of the material emitter which is shown in Figure; Figure 6 is a perspective view of the emitted material and the selectively formed laminar shroud which is emitted by the nozzle assembly which is shown in Figures 4 and 5; and Figure 7 is a perspective view of the material emitter which is shown in Figure 1 and which illustrates the selective placement of paint upon certain targeted portions of a vehicle. Referring now to Figures 1-3 and 7, there is shown a material emitter 10 having a nozzle assembly 12 which is made in accordance with the teachings of the present invention. As shown, material emitter 10 includes a generally hollow material reception portion 11 which is physically and communicatively coupled, by conduit and/or hollow member 13, to a pressurised source 16 of material 17, such as paint or some other type of selectively emitted material. Portion 11 is further physically and communicatively coupled, by conduit and/or hollow member 29, to a pressurised source 19 of gas 21. Particularly, the gas 21 and material 17 are communicated into the cavity 22 which is formed within portion 11 and are mixed within the cavity 22, effective to form material mixture 25 (e.g., in one non-limiting embodiment, the gas or material 21 selectively atomises the material 17 and the atomised material 17 and the atomising gas or material 21 enters the generally hollow nozzle portion 23 and is selectively emitted from the nozzle assembly 12). Particularly, the selectively created material mixture 25 is emitted, from aperture 61 which is formed within the material emission or nozzle portion 23 of the nozzle assembly 12, as a substantially conical shaped spray or mixture spray pattern 24. More particularly, the material 17 which is included within the mixture spray pattern 24 is selectively deposited upon a targeted location 18 which, in one non-limiting embodiment, may form a part or portion of a vehicle or automobile 20. It should be appreciated that other types of mixture spray patterns 24 (i.e., other shapes and/or sizes of spray patterns) may occur and/or be selectively formed by the material emitter 10, depending upon the type of nozzle assembly 12 which is utilised by the material emitter 10 and/or depending upon the type of gas 21 and/or material 17 which is utilised by the material emitter 10. It should additionally be realised that the principles of this invention are equally applicable to the use and/or selective formation of these other types of spray patterns and to a material emitter 10 which does not mix material 17 with material 21, but which selectively and alternatively utilises and emits only material 17 within the created and/or formed mixture spray pattern 24. While a hand-held paint applicator or material emitter 10 is shown, it should also be appreciated that material emitter 10 may comprise virtually any other type of material applicator and that material 17 may comprise paint or virtually any other type of material which is desired to be selectively deposited upon a targeted location 18 and/or object 20. Further it should be appreciated that, in one non-limiting embodiment, portion 23 of the nozzle assembly 12 may be removably secured within portion 11. Alternatively, nozzle assembly 12 and/or nozzle portion 23 is integrally formed within portion 11. In order to substantially increase the likelihood that the emitted material 25 is deposited only upon the targeted portion 18 and/or only upon the targeted object 20, that the emitted material 25 (i.e., in one non-limiting embodiment, the liquefied portion 17 of the mixed material 25) is deposited in an overall aesthetically pleasing manner, and that the deposited material portion 17 forms substantially "clean", "crisp", and "straight" edges, it is desirable to substantially reduce and/or eliminate the relatively turbulent shear type layer or turbulent portion which is formed around and/or which typically exists within and/or along the conical edge 30 of the mixture spray pattern 24 and which occurs due to the undesired entrainment of ambient air or material 33 within the emitted material mixture 25. In the preferred embodiment of the invention, a second material, as is more fully delineated below, is operatively used to substantially reduce and/or eliminate the turbulent shear layer and/or a portion of the turbulent shear layer within the mixture spray pattern 24. As best shown in Figures 1 and 3, a pair of substantially similar and generally "C"-shaped channel or "shroud forming" members 26, 28 are removably attached to the material emission portion 23 of the nozzle assembly 12. Particularly, as shown, in one non-limiting embodiment, the material emission portion 23 includes opposed pairs of channels, 32, 34; and 36, 38 which respectively reside upon the opposed top and the bottom surfaces 63, 65 of the portion 23. Each surface 63, 65 respectively and wholly resides in and/or forms a plane which is substantially parallel to the longitudinal axis of symmetry 40 of nozzle assembly 12. Each of the channels 32, 34, 36, and 38 are each of a substantially identical length and width. As shown, each member 26, 28 has a pair of substantially identical flange or "feet" portions 41, 42 which generally conform to the shape of each of the channels 32-38 and which are each adapted to be frictionally and removably placed within a unique one of the channels 32-38. Hence, channels 32-38 co-operate with the flange members 41, 42 of each respective member 26, 28 to allow the "shroud forming" members 26, 28 to be removably secured to the nozzle portion 23 and to co-operate with the nozzle portion 23 to form "shroud generating" cavities and/or channels 50, 52. It should be appreciated that other members which are substantially similar to members 26, 28 may concomitantly or alternatively be placed upon surfaces 54, 56 of member or portion 23 and function in a substantially similar manner as members 26, 28. It should be further appreciated that in another non-limiting embodiment, only a single member 26 or 28 may be used. As shown best in Figure 1, each member 26, 28 is communicatively coupled to a pressurised source of a second material, such as and without limitation, gas 21, through material emitter 11. In another non-limiting embodiment, each channel 50, 52 may be coupled to a source of a second material by respective tubes or conduits (not shown). Each member 26, 28 operatively and communicatively receives the second material within respective cavities 50, 52, thereby causing the second material, such as the pressurised gas 21, to be emitted along certain portions of the conically shaped edge 30, thereby substantially preventing the formation and/or eliminating the relatively turbulent shear layer at these certain edge portions by forming a laminar flow layer or "shroud" along and/or over these edge portions. By utilising a member, such as one of the members 26, 28, upon each of the surfaces 54, 56, 63, 65, a laminar flow shroud may be selectively formed which substantially surrounds the entire emitted mixture spray pattern 24. In one non-limiting embodiment, the velocity of the emitted material emanating from channels 50, 52 is substantially equal to the velocity of the emitted material mixture 25. Further, the height 58 of each of the channels 50, 52 is about one half of the height 59 of the outlet aperture 61 through which the material mixture 25 is selectively emitted. In prior art spray nozzles as shown in Figures 4-5, members 26, 28 are replaced by a shroud member 60. Particularly, shroud member 60 is of substantially the same shape as is portion 23 but is slightly larger in size. In operation, member 60 is placed over member 23 (i.e., member 60 selectively, receivably, and operatively receives member 23) and a gap 70 is formed between member 60 and surfaces 54, 56, 63, and 65 of member 23. The second material, such as material 21, is communicatively coupled within and/or to this gap 70, and, as shown best in Figure 6, forms a conical shaped shrouding spray pattern 64 which substantially surrounds substantially the entire emitted mixture spray pattern 24 (i.e., the shrouding pattern 64 is formed along and/or around the entire conical edge 30), thereby substantially and further eliminating and/or reducing the turbulent shear layer at each portion of the conical spray surface.

Claims: A spray nozzle for spraying a first material, comprising a mixture nozzle portion (23) for forming a spray pattern (24) containing the first material (17), and a shroud nozzle portion (26,28) for forming a shrouding spray pattern (64) containing a second material (19) which shrouds at least part of the mixture spray pattern (24), the shroud nozzle portion (26,28) being arranged relative to the mixture nozzle portion (23) so that the shrouding spray pattern (64) borders and flows alongside the mixture spray pattern (24) to prevent the formation of a shear layer on the outer edge (30) of the mixture spray pattern (24), characterised in that said mixture nozzle portion (23) includes first and second channels (32, 34) and wherein said shroud nozzle portion (26) is substantially "C"-shaped and includes a first flange portion (41) which removably resides within said first channel (32) and a second flange (42) portion which removably resides within said second channel (34). A spray nozzle as claimed in claim 1, wherein the velocities of the two spray patterns are substantially equal. A spray nozzle as claimed in claim 1 or 2, wherein said first material comprises paint and wherein said second material comprises gas. A spray nozzle as claimed in any preceding claim, wherein said first material is a mixture including gas. A spray nozzle as claimed in any preceding claim, wherein said mixture spray pattern (24) is substantially conical. A spray nozzle as claimed in any preceding claim, wherein said second material (19) substantially surrounds said mixture spray pattern (24). A spray nozzle as claimed in any preceding claim, wherein said shroud nozzle portion (60) receivably contains said mixture nozzle portion (23). A spray nozzle as claimed in any preceding claim, wherein said shroud nozzle portion (26) removably resides upon one surface of said mixture nozzle portion (23). A nozzle assembly as claimed in claim 8, wherein said one surface comprises a top surface.

Inventors: GOENKA LAKHI NANDLAL, SKENDER MALGORZATA M, GOENKA, LAKHI NANDLAL, SKENDER, MALGORZATA M.
Applicants: FORD GLOBAL TECH INC, FORD GLOBAL TECHNOLOGIES, INC.
Application year: 2000
Main classification: B05B7
IPC codes: B05B7, B05B15