Apparatus and method for filling packages with a fluid material

Abstract: A fluid filling assembly includes a discharge nozzle arrangement (54,72) which includes a closely wound spring (72) operatively connected at its outer periphery to a diffuser chamber (68) and including a plurality of coils (74) adapted to retain a volume of fluid thereabove until the fluid is forced under pressure against the spring (72) or an associated valve member to urge the coils (74) apart to provide clearances therebetween for the flow therethrough of the fluid.

Description: This invention relates generally to packaging apparatus and methods, 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 discloses various spaced apart, perforated plate designs 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 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 plate. US-A-4,119,276 discloses a laminar stream faucet spout attachment including spaced apart perforated plates and screens. 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. Each of 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-4995431 which, like US-A-4 958 669, discloses the features of the preamble of claims 1 and 25, discloses a liquid filling machine in which the outlet mouth of a filling nozzle has hinged to respective opposite sides thereof respective dampers connected by respective links to the lower end of a vertical stem. The stem is guided through a spider above the dampers and a helical compression spring acts between the spider and a collar encircling the stem at a location above the dampers. Acting between the collar and a valve closure member encircling the stem at a location above the collar is a second helical compression spring which urges the valve closure member upwardly towards an abutment on the stem. The closure member co-operates with an encircling valve seat in the filling nozzle. A piston-and-cylinder device pumps liquid under pressure into the filling nozzle at a location above the valve seat, the liquid forces open the closure member and thus the dampers against the action of the springs and flows down past the springs, the collar, the spider, the links and the dampers into a container. DE-A-528623 discloses a valve in the form of a spring wound in such a way that its shape is part-spherical. The coils of the spring form the sealing surfaces and are moved apart by the pressure of the fluid which they control. The valve is used mainly for compressors, pumps and similar machines and is particularly suitable for high revolutions per minute. US-A-3957083 discloses a pressure-sensitive regulating valve in the form of a coil spring mounted in a duct in which fluid flow is to be regulated, in the field of rocketry or any other area in which great variance in pressure occurs. The spring is open at both ends, although its upstream open end may be closed by a convexly-shaped, solid-wall baffle. The coils of the spring are spaced apart and the fluid flow is regulated by the fluid-pressure-responsive, axial contraction and expansion of the spring to adjust the free-flow area of the valve. JP-A-58/91978 discloses a valve in the form of a spiral elastic body carrying holes and clearances. When the spring changes shape, either fluid can pass through the holes or fluid flow can be prevented. When the spring rotates it emits a signal. According to one aspect of the present invention, there is provided packaging apparatus for filling packaging with fluid material, comprising a duct through which the fluid material flows, pumping means for forcing the fluid material through the duct and an openable valve which prevents flow of said fluid material through said duct characterised in that said valve comprises a coil spring whereof a plurality of coils directly contact the fluid material in the duct, said coils openably sealing said duct against flow of said fluid material and, upon opening, allowing flow of said fluid material through clearances among said coils. According to another aspect of the present invention, there is provided a packaging method comprising forcing fluid material through an openable valve which otherwise prevents flow of said fluid material therethrough, and filling packaging with the fluid material forced through said valve, characterized in that the said forcing of the fluid material comprises forcing apart coils of a spring constituting said valve to create clearances among said coils, which otherwise seal against flow of said fluid material thereamong. Owing to the present invention, it is possible to provide, for a fluid material packaging machine, a valve which is of very simple construction and is easily and efficiently cleanable in place and sanitized. The valve may be at the discharge end of a filler nozzle for preventing, by the surface tension of the liquid or by complete coil-to-coil closure, liquid from flowing out of the nozzle body under gravity. It is possible to provide a plurality of variously shaped tension springs serving as valves for the discharge end of a nozzle body to serve the above-mentioned function. 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 cross-sectional views of a filler mechanism; Figure 2 is an enlarged fragmentary cross-sectional view of the inventive portion of the Figure 1 mechanism; Figure 3 is an enlarged fragmentary cross-sectional view of an alternative embodiment to the Figure 2 structure; Figure 4 is a cross-sectional view illustrating the Figure 3 structure in an operational mode; Figures 5-7 are perspective views of alternative embodiments, Figures 8, 10 and 12-14 are cross-sectional views of still seven more alternative embodiments, and Figures 9 and 11 are cross-sectional views illustrating the respective Figures 8 and 10 structures in operational modes. 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 being 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 cooperative 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 and 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. Referring now to Figure 2, there is illustrated a flat coil spring 72, shown in its normal closed condition. In this condition, the spring 72 may be wound such that adjacent coils 74 are either slightly touching, so as to not wedge together, or spaced apart with a slight clearance therebetween such that the surface tension of the liquid serves to retain the liquid product in the chamber 68 without dripping through the slight clearance. This arrangement is suggested for use with the, so-called, "bottom-up" type filling process, i.e., when either the container is lowered or the nozzle housing is lifted to fill the container during the relative withdrawal motion between the container and the nozzle housing. Figure 3 illustrates a spring nozzle wherein the spring 72a is upwardly open, conical in shape in its normal closed condition, with adjacent coils thereof touching. Figure 4 shows the spring 72a in its extended position under the force of the fluid thereabove, as will be explained. This arrangement is considered to be more suitable for a "top-down" type filling process, i.e., no relative movement between the container and the nozzle housing 54. The reason for this is that the horizontal velocity component, represented as h in Figure 4, serves to reduce the vertical downward velocity of the liquid out of the nozzle, to produce more of divergent flow characteristic represented by the arrows in Figure 4. This reduces splash at the bottom of the container by virtue of some flow occurring down the walls of the container, thereby diminishing foam buildup. Figure 5 is a perspective view of a spring 72b similar to the Figure 3 spring 72a. Figure 6 is a perspective view of an alternate pyramidal-shaped spring 72c embodiment, which fits the typical four-sided container opening and thus tends to minimize the vertical exit velocities of the liquid. Figure 7 is a perspective view of a spring 72d variation of the Figure 6 embodiment, wherein two oppositely disposed sides 76 of the spring 72d are formed to be converged inwardly to assume a shape substantially comparable to a paperboard carton top opening wherein typical gable-type side panels are pre-broken along converging score lines, prior to the filling step. After filling the carton, the panels are more readily fully closed and sealed. Figure 8 illustrates a further alternate spring 72e embodiment similar to Figure 3, but formed in a substantially parabolic shape. As such, under the force of fluid thereabove, the coils 74 spread further apart at the upper outer portion than at the lower central portion, as indicated in Figure 9. As a result, the fluid forced therethrough attains somewhat of a divergent flow characteristic, suitable for top-down filling applications. Progressively wound springs, i.e., springs in which the spring varies in rating along its length, allow selection of various characteristics. Figure 10 illustrates a still further alternate spring 72f embodiment, wherein the coils 74 are formed with an inward arcuate cross-sectional contour relative to the conical shape of the Figures 3 and 5 embodiments. As such, under the force of fluid thereabove, the coils 74 spread further apart at the lower central portion than at the upper outer portion, as indicated in Figure 11. As a result, the fluid forced therethrough attains substantially a vertical flow characteristic, suitable for bottom-up filling applications. Figures 12A, 12B and 12C illustrate that coils 74a of a spring 72g, 72h and 72i, respectively, may be formed with a four-sided cross-sectional shape, rather than a round or oval cross-sectional shape. Such four-sided coil shapes are adaptable to any of the springs 72, 72a, 72b, 72c and 72d. The four-sided cross-sectional shape is preferably oblong rectangular. As such, the coils 74a are annularly stepped in a generally conical configuration with the long sides (1) positioned horizontally (Figure 12A); or (2) positioned diagonally (Figure 12B); or (3) positioned vertically (Figure 12C). Referring now to Fig. 13, a valve seat 78 is formed in the lower chamber 68. A valve 80 is secured to an end of a valve stem 82 for seating cooperation with the valve seat 78. The other end of the valve stem 82 is secured to the center of the spring 72a, for example, which urges the valve 80 into seating engagement with the valve seat 78. In this arrangement, since the liquid from the chamber 68 must first unseat the valve 80 from the seat 78 and then flow radially outwardly and then downwardly therepast, as the clearance between the valve 80 and the seat 78 progressively increases, lower filling velocities are experienced and initial spurting or spraying through the coils 74 is avoided. If desired, the coils may fully close, with the valve 80 retained just short of closing against the seat 78. Referring now to Figure 14, in this arrangement, a piston 84, having an o-ring 86 mounted around the outer periphery thereof, is slidably mounted in the chamber 50. A rod 88 extends upwardly through an opening 90, with a handle 92 formed on the outer end thereof. A coil spring 94 is compressed between the piston 84 and a seat 96 at the upper surface of the chamber 50. A valve stem 98 extends downwardly from the piston 84 to a check valve 100. The valve 100 is urged downwardly onto a valve seat 102 by the coil spring 94. A first extension stem 104 extends downwardly from the valve 100 in the chamber 68. A second extension stem 106 is connected by a dowel pin 108 to the first extension stem 104, and extends to a spring 110 at the exit end of the housing 54. The spring 110 is wound in an inverted cone shape and closed in its inoperative state, i.e., when the valve 100 is on the seat 102. In this arrangement, flow through the spring 110 when the valve 100 is lifted from the seat 102, is in a converging configuration, more suitable for a bottom-up filling application. If there are inter-coil spaces for each of the above described spring embodiments in its liquid-retaining condition, the areas of the individual spaces and the total area thereof, relative to the overall coil area, are such as to produce the result that surface tension of the liquid above the spring coils will prevent the liquid from flowing through the spaces under the force of gravity. 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, low-ring the check valve 56 (Figure 1B), or raising the check valve 100 (Figure 14). This, in turn, forces the equivalent volume of fluid from the lower chamber 68 through the spaces between spring wires, into a selected size carton represented as 112 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 112 relative to the nozzle housing 54 for bottom-up filling applications. 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. In the Figure 14 embodiment, once the pumping stroke is completed, the spring 94 urges the valve 100 downwardly, but short of engaging the seat 102, so that the spring nozzle 110 is assured of fully closing. Retraction of the piston 34 (Figure 1A) downwardly in the chamber 14 pulls the valve 20 away from the seat 22 to once again fill the chamber 14 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 spring coils serve to retain the liquid in the nozzle chamber 68 either by sealingly touching each other or by virtue of the surface tension of the liquid adjacent the coils. For those springs whose spring coils sealingly touch each other, such a spring may serve as a spring-form check valve in a fluid line upstream of a discharge end or nozzle. The liquid-retaining springs may be of stainless steel, rubber, plastics, or glass. The rates of the liquid-retaining springs are low, as is any pre-set tension therein, to avoid high-velocity exit streams during filling. By low-rate is meant less than 200N/m, preferably between 15N/m and 130N/m. The liquid-retaining springs have the advantages that they are less liable to be clogged by such things as product flakes and butter-fat than are conventional screens, and that good diffusion, laminar flow and shut-off characteristics are obtainable with them. It should be apparent that the embodiments described above provide an improved nozzle arrangement for a filler assembly, which efficiently retains liquid, and generally need not be disassembled and autoclaved in order to be thoroughly cleaned. It should be further apparent that the spring nozzle shapes may be varied to be adaptable to either bottom-up or top-down carton filling applications, and that the coils thereof may be formed of various cross-sectional shapes.

Claims: Packaging apparatus for filling packaging with fluid material, comprising a duct (68) through which the fluid material flows, pumping means (34) for forcing the fluid macerial through the duct (68) and an openable valve (72;110) which prevents flow of said fluid material through said duct (68); characterised in that said valve (72;110) comprises a coil spring (72;110) whereof a plurality of coils (74) directly contact the fluid material in the duct (68), said coils (74) openably sealing said duct (68) against flow of said fluid material and, upon opening, allowing flow of said fluid material through clearances among said coils (74). Apparatus according to claim 1, characterized in that said duct (68) terminates as a nozzle (54) at which said coils (74) are situated. Apparatus according to claim 1 or 2, characterized in that the action of said pumping means (34) on the fluid material urges said coils (74) apart to provide said clearances. Apparatus according to any preceding claim, characterized in that said spring (72) is flat. Apparatus according to any preceding claim, characterized in that adjacent coils (74) of said spring (72;110) in their fluid-retaining condition are positioned so as to provide predetermined spaces therebetween, and in that the respective and overall areas of the spaces are such that surface tension of the fluid material in said duct (68) will prevent the fluid material from passing therethrough under the force of gravity. Apparatus according to any preceding claim, characterized in that the spring (72;110) is dished in shape. Apparatus according to claim 6, characterized in that the shape of said spring (72b) when not in use is conical. Apparatus according to claim 6, characterized in that the shape of said spring (72c) when not in use is pyramidal. Apparatus according to claim 6, characterized in that said spring (72d) is formed with two parallel sides and two oppositely disposed inwardly converging sides (76). Apparatus according to claim 6, characterized in that said spring (72e) is parabolic in axial section. Apparatus according to claim 6, characterized in that said spring (72f) is cusp-shaped in axial section. Apparatus according to any one of claims 6 to 11, characterized in that the shape of said spring (110) when not in use is open in a downstream direction. Apparatus according to any preceding claim, wherein said coils (74) are of substantially circular cross-section. Apparatus according to any one of claims 1 to 12, characterized in that said coils (74) are four-sided in cross-section. Apparatus according to claim 14, characterized in that said coils (74a) are oblong rectangular in cross-section. Apparatus according to claim 15, characterized in that the longer sides of the cross-sections of the coils (74a) are positioned substantially perpendicularly to a longitudinal axis of said duct (68). Apparatus according to claim 15, characterized in that the longer sides of the cross-sections of the coils (74a) are positioned obliquely to a longitudinal axis of said duct (68). Apparatus according to claim 15, characterized in that the longer sides of the cross-sections of the coils (74a) are positioned parallelly to a longitudinal axis of said duct (68). Apparatus according to any preceding claim, characterized in that a valve seat (78;102) is formed in said duct (68), a valve stem (82;104-108) is secured at one end thereof to the centre of said spring (72;110), and a valve member (80;100) is formed on the other end of said stem (82;104-108) for seating co-operation with said valve seat (78;102). Apparatus according to claim 2, or any one of claims 3 to 19 as appended to claim 2, characterized in that said spring (72;110) is secured to the rim of the outlet mouth (70) of said nozzle (54). Apparatus according to claim 20 as appended to claim 19, characterized in that said valve seat (78;102) is formed a predetermined distance upstream of said outlet mouth (70). Apparatus according to claim 21 as appended to claim 6, characterized in that the shape of said spring (72a) when not in use is open in an upstream direction and said spring (72a) urges said valve member (80) against said valve seat (78) and in that said fluid material under pressure presses said valve member (80) towards said spring (72a). Apparatus according to claim 21 as appended to claim 12, characterized in that said fluid material under pressure presses said valve member (100) away from said spring (110). Apparatus according to any preceding claim, wherein the spring (72,110) is of a rate less than 200N/m. A packaging method comprising forcing fluid material through an openable valve (72;110) which otherwise prevents flow of said fluid material therethrough, and filling packaging with the fluid material forced through said valve (72;110), characterized in that the said forcing of the fluid material comprises forcing apart coils (74) of a spring (72,110) constituting said valve (72,110) to create clearances among said coils (74) , which otherwise seal against flow of said fluid material thereamong.

Inventors: ESPER LEO JOSEPH, ESPER, LEO JOSEPH
Applicants: ELOPAK SYSTEMS, ELOPAK SYSTEMS AG
Application year: 1993
Main classification: B65B39
IPC codes: B67C3, B65B39