Filler nozzle

Abstract: A fluid flow apparatus includes a discharge nozzle arrangement (48) which may comprise a single, continuous, meandering, stainless steel strand 74 to create a planar screen 72 operatively connected at its outer periphery to the wall 54 of a diffuser chamber 68. The screen 72 is adapted to retain a volume of fluid thereabove until the fluid is forced under pressure through the openings between adjacent segments of the strand 74. Portions of the screen 72 are adapted to flex resiliently downwardly, out of the plane of the outer periphery, to provide additional clearances between adjacent segments of the screen 72, in the event that particulates should tend to build-up, thereby to resist clogging by flushing same. A round cross-section of the strand 74 facilitates continual cleanliness, and serves to produce better-behaved flow out of the nozzle 48, thereby reducing foaming of the product being discharged during the filling operation. As an alternate embodiment, a broken-line etched screen serves to provide the downwardly flexing feature when clogging tends to occur.

Description: This invention relates generally to fluid flow apparatus, but more particularly to filler nozzles for filling liquid-carrying containers. Devices for preventing liquid from flowing out of nozzle bodies under gravity have been addressed heretofore. For example, US-A-4,958,669 corresponds to the preamble of claim 1 and discloses various spaced-apart, perforated plate designs consisting of intersecting, connected warp and weft portions, for use within the discharge end of the nozzle body for the purpose described above. The suggested plates have a particular thickness and any of square, circular, triangular, or hexagonal etched-out openings formed therein, with a specified opening ratio of the total volume of the openings to the total volume, inclusive of the openings, of the etched plate. US-A-3,672,574 discloses a device for aeration of a water jet and applicable to discharge spouts, e.g. for wash basins. In one embodiment, a baffle jet stabilizer is formed in one piece with the discharge end of a tubular body screwed into the discharge end of the discharge spout. It takes the form of a large mesh made of radial elements, some ramifications including fingers, departing therefrom in such a way as to define a plurality of braked passages for the jet. This document forms the basis for the preamble of claim 9. US-A-4,119,276 discloses a laminar stream faucet spout attachment including spaced-apart perforated plates and nettings. US-A-3,415,294 discloses a plurality of relatively closely spaced fine mesh screens, separated by O-rings, at the discharge opening of a liquid filling machine for eliminating or minimizing the formation of foam as the liquid is poured through the screens into containers. US-A-3,630,444 and US-A-3,730,439 disclose stacked, downwardly semispherical or concaval screens. US-A-2,643,104 and US-A-4,730,786 disclose upwardly semispherical or concaval disc screens and/or cone screens. US-A-3,104,819 discloses a screen consisting of a spiral spring of wire or strip form and attached centrally to a handle and peripherally to the internal wall of a discharge spout of a water jet aeration device. To clear the screen of foreign matter, the handle is displaced axially inwardly of the spout to space further apart the turns of the spring. US-A-5,335,862 corresponds to the preamble of claim 6 and discloses closely wound coil springs of various configurations, wherein the coils are deflected downwardly so as to be urged apart under fluid pressure to permit flow therepast. According to one aspect of the present invention, there is provided a nozzle for use at a chamber of a fluid machine, said nozzle comprising a screen lying in an imaginary surface and having clearances among adjacent segments thereof and operatively connected to said chamber, said screen being adapted (1) to retain fluid thereabove under the surface tension of the fluid, and (2) when a downward force is applied to said fluid, to permit the fluid to flow through said clearances while the screen substantially remains lying in said imaginary surface, characterized by said screen being adapted also (3), in the event of randomly positioned build-up of particulates, to flex to permit the particulates to pass through resultant enlarged clearances. Owing to the flexing of the screen to enlarge the clearances where a build-up of particulates is occurring, the screen can clear itself of particulates. According to another aspect of the present invention, there is provided apparatus comprising a fluid flow duct having a longitudinal axis, and a screen disposed in the path of fluid flow through said duct, and consisting of a continuous, flexible, elongate element which lies substantially in an imaginary surface extending transversely of said longitudinal axis, characterized in that said continuous, flexible, elongate element meanders in said imaginary surface. Owing to the meandering form of the continuous, flexible, elongate element, it is possible to arrange that it flexes readily to enable particulates to pass readily through the screen. According to a further aspect of the present invention, there is provided apparatus comprising a fluid flow duct having a longitudinal axis, and a screen disposed in the path of fluid flow through said duct, and comprising portions in the form of cantilevers lying substantially in an imaginary surface transverse to said longitudinal axis, characterized in that said cantilevers are resiliently turnable out of said imaginary surface. Since the cantilevers can turn resiliently out of the imaginary surface, they can more readily allow particulates to pass through the screen. An advantage of the invention is that it can provide an improved screen for a fluid flow duct, in particular an improved discharge nozzle for a fluid machine, especially an improved metal netting nozzle arrangement for a liquid filler assembly. Another advantage of the invention is that it can provide an improved nozzle arrangement at the discharge end of a filler nozzle for preventing the liquid from flowing out of the nozzle body under gravity by the surface tension of the liquid, and is adapted to being easily and efficiently cleaned in place and sanitized. A further advantage of the invention is that it can provide variously shaped screens, formed by either a single, continuous, meandering strand, or a broken line netting, each mounted in the discharge end of a filler nozzle body to serve the above-mentioned function. A still further advantage of the invention is that the screens may be formed by stainless steel strands, moulded plastics, or etched plates. The stainless steel strands may be round cross-section wire, and the plastics may be moulded with a round cross-section, while the etched plates would consist of square cross-section components. Still another advantage of the invention is that it can provide such screens wherein the fluid is retained thereabove by the fluid surface tension until force is applied to discharge the fluid through the clearances, with downward deflection or flexing occurring as required to prevent build-up of particulates or pulpy products. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which :- Figures 1A and 1B are fragmentary, vertical, axial sectional views of a filler apparatus; Figures 2 to 6 are plan views of alternate, continuous, meandering, single-strand screens of the Figure 1 apparatus; and Figures 7 and 8 are enlarged, fragmentary, plan views of alternative, etched-plate screens of the Figure 1 apparatus. Referring now to the drawings in greater detail, Figures 1A and 1B illustrate a filler apparatus 10 including a filler body 12 having a chamber 14 therein for receiving a predetermined volume of liquid from an overhead tank, represented as 16, via a vertical passageway 18. A first check valve 20 cooperates with a seat 22 formed in a neck 24 at the upper end of the chamber 14. A valve stem 26 extends upwardly from the valve 20 through the neck 24 to be connected at the upper end 28 thereof to a spring 30 mounted at the lower end thereof on a fixed perforated member 32, so as to urge the valve 20 upwardly against the seat 22. A piston 34 having an O-ring 36 mounted in a groove 38 formed around the periphery thereof, is slidably mounted in the chamber 14. A downwardly extending shaft 40 from the piston 34 is adapted to be connected to cylinder means (not shown). An outlet opening 44 is formed in the body 12, leading into a downwardly sloping elbow 46 to a nozzle body 48. A chamber portion 50 at the lower end of the elbow 46 is secured by suitable fasteners, represented as 51, to the nozzle body 48. The nozzle body 48 includes a valve seat section 52 and a housing 54 secured together by suitable fasteners, represented as 55. A second check valve 56 having an O-ring 58 mounted thereon is co-operative with a seat 60 formed in the body 48 at the base of the valve seat section 52. A spring 62 is connected to a stem 64 extending upwardly from the valve 56. The spring 62 is mounted at its lower end thereof on a fixed perforated member 66 so as to urge the valve 56 and O-ring 58 upwardly against the seat 60. The housing 54 includes a lower chamber 68 below the valve 56, terminating at a discharge end 70. Depending upon the application, one or multiple planar stainless steel screens 72 are mounted in the discharge end 70. The screens may be spaced apart by suitable spacers 73. The screens 72 may take any of the forms of the screens 72a to 72e of Figures 2 to 6 and be formed by repeatedly bending a single continuous strand of stainless steel wire 74 into a predetermined meandering configuration. Alternately, the screens 72 may be moulded of a suitable polymer. As a further alternative, the screens 72 may take the form of either of the screens 72f and 72g of Figures 7 and 8. It will be noted that portions of each screen 72a to 72d, 72f and 72g form cantilevers 75, whereby, if and when some build-up of particulates occurs above those cantilevers, the resulting increased downward pressure thereon causes the cantilevers to flex resiliently downwards to allow the particulates to pass through the screen. Figure 3 illustrates a discharge screen 72b configuration similar to the screen 72a of Figure 2, but with the path traversed by the strand thereof providing wider spaces between adjacent segments, so as to be suitable for thicker fluids, such as cream, buttermilk, or a pulpy product, for example. Figures 4 and 5 illustrate alternate fine and coarse meandering strand 74 configurations producing discharge screens 72c and 72d. Figure 6 illustrates still another alternate embodiment, wherein the strand 74 is formed to traverse a back-and-forth, substantially parallel and progressive path configuration producing a screen 72e. As regards the spaces provided between adjacent segments of the single, continuous, meandering path for each of the above-described metal screen embodiments in its liquid-retaining condition, the areas of the individual spaces and the total area thereof, relative to the overall screen area, are such as to produce the result that surface tension of the liquid above the screen will prevent the liquid from flowing through the spaces under the force of gravity until a downward force is applied thereto. Figures 7 and 8 illustrate further embodiments made by etching stainless steel sheets to form respective discharge screens 72f and 72g comprised of broken-line, stainless steel, rectangular cross-section, links 76. The overall operation of the filler assembly 10 is conventional, i.e., the filler assembly is first primed such that the chamber 14 and the nozzle body 48 chambers 50 and 68 are filled with a selected liquid product. The assembly is then ready for the production run. When cycled, the piston 34 moves upwardly, forcing a predetermined, measured volume of liquid from the chamber 14 through the outlet opening 44 and the sloping elbow 46 and, thence, into the valve seat section 52, lowering the check valve 56 (Figure 1B). This, in turn, forces the equivalent volume of fluid from the lower chamber 68 through the spaces between adjacent segments of the screen(s), into a selected size carton, represented as 78 in Figure 1B, positioned therebelow by the usual indexing conveyor and/or lifting mechanism (not shown). Conventional external means may be employed to raise and lower the carton 78 relative to the nozzle housing 54 for bottom-up filling applications. Significant downward deflection or random area flexing of the screens 72 will not occur unless and until some build-up of particulates, e.g. pulpy materials, begins to occur, at which time the resilient deflection or flexing will allow the build-up to pass through the resultant spread-apart clearances. Once the pumping stroke is completed, the spring 62 (Figure 1B) urges the valve 56 and O-ring 58 upwardly into contact with the seat 60, with the chamber 68 remaining full. Retraction of the piston 34 (Figure 1A) downwardly in the chamber 14 pulls the valve 20 away from the seat 22 to fill the chamber 14 once again with the selected volume of fluid, whereupon the spring 30 urges the valve 20 into contact with the seat 22, ready for the next cycle. At this point, the various screens once again serve to retain the liquid in the nozzle chamber 68 by virtue of the surface tension of the liquid adjacent the screens. If desired, instead of the screen lying in a planar surface transverse to the axis of the nozzle body, it may lie in a curved surface transverse to that axis. Industrial Applicability It is apparent from the Figures 2-5, 7, 8 and 6 that any of the screen configurations may have an outer rectangular or circular formation, so as to accommodate particular chamber 68 discharge ends 70. It should be apparent that examples of the invention provide stainless steel or moulded plastic screens, which may consist of round cross-section strands, in contrast to known woven netting packs having over-and-under lapped wires, and that the round cross-section single-strand screens are particularly adaptable to easy cleanability compared with woven netting packs, and to producing a better-behaved flow out of the nozzle compared with etched plates, thereby reducing foaming of the product being discharged during the filling operation. It should also be apparent that the screens described with reference to the drawings will deform outwardly under sufficient pressure to allow particulates to pass through into the container, without clogging the screen, and then will resume their optimal planar configuration for smooth flow and shut-off.

Claims: A nozzle for use at a chamber of a fluid machine, said nozzle (48) comprising a screen (72) lying in an imaginary surface and having clearances among adjacent segments thereof and operatively connected to said chamber (68), said screen (72) being adapted (1) to retain fluid thereabove under the surface tension of the fluid, and (2) when a downward force is applied to said fluid, to permit the fluid to flow through said clearances while the screen (72) substantially remains lying in said imaginary surface, characterized by said screen (72) being adapted also (3), in the event of randomly positioned build-up of particulates, to flex to permit the particulates to pass through resultant enlarged clearances. A nozzle according to claim 1, wherein said screen (72a-72d, 72f, 72g) comprises portions in the form of cantilevers (75) which randomly flex downwardly in said event of build-up of particulates. A nozzle according to claim 1 or 2, wherein said screen (72a-72e) has been formed by repeatedly bending a single continuous strand of wire (74) into a predetermined meandering configuration. A nozzle according to claim 1 or 2, wherein said screen (72f, 72g) has been formed by etching a metal plate to produce a perforated plate (72f, 72g) comprising a plurality of broken-line, flexible segments. A nozzle according to claim 4, wherein said perforated plate (72f, 72g) includes square cross-section material portions with intermediate perforations. Apparatus comprising a fluid flow duct (54) having a longitudinal axis, and a screen (72a-72e) disposed in the path of fluid flow through said duct (54), and consisting of a continuous, flexible, elongate element (74) which lies substantially in an imaginary surface extending transversely of said longitudinal axis, characterized in that said continuous, flexible, elongate element (74) meanders in said imaginary surface. Apparatus according to claim 6, wherein said elongate element (74) is in the form of a single strand of wire (74). Apparatus according to claim 6 or 7, wherein said screen (72a-72e) serves to retain fluid thereabove under surface tension of said fluid. Apparatus comprising a fluid flow duct (54) having a longitudinal axis, and a screen (72a-72d, 72f, 72g) disposed in the path of fluid flow through said duct (54), and comprising portions in the form of cantilevers (75) lying substantially in an imaginary surface transverse to said longitudinal axis, characterized in that said cantilevers (75) are resiliently turnable out of said imaginary surface. Apparatus according to claim 9, wherein said screen (72a-72e) consists of a continuous elongate element (74) which lies and meanders substantially in said imaginary surface. Apparatus according to claim 9, wherein said screen (72f, 72g) consists of a sheet (72f, 72g) formed with holes distributed thereover. Apparatus according to any one of claims 9 to 11, wherein said screen (72a-72d, 72f,72g) serves to retain fluid thereabove under surface tension of said fluid.

Inventors: MCDONALD KENNETH PAUL, MCDONALD, KENNETH PAUL
Applicants: ELOPAK SYSTEMS, ELOPAK SYSTEMS AG
Application year: 1995
Main classification: B65B39
IPC codes: B67D3, B05B1, B65B39