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(11) | EP 0 262 762 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Valve for beer keg |
| (57) A valve (10) for use with a beverage container is fully compatible with, and enhances
the utility of, conventional automatic filling equipment. The valve is preferably
of formed of plastic components and is therefore can form an economical throw-away
unit in combination with a plastic keg. A cylindrical outer cage (18) includes a plurality
of lengthwise apertures (20,22,24,26,). A transversely-oriented deflector plate is
fixed to an inner cage (30) that is movable with respect to the outer cage. springs
(38) urge the inner and outer chambers of the valve to closed positions. The valve
is arranged so that both chambers are opened by the insertion of the filling head
of a conventional automatic racking machine. The plate deflects a pressurized beverage
input, lessening agitation and turbulence, whereby only minimal, if any, foam or head
is generated during the filling process. |
[0001] The present invention relates to valves for use in conjunction with the filling and dispensing of beer and related liquids from keg-like containers. More particularly, this invention pertains to a valve that enhances the filling process and is sufficiently economical for "throw-away" use.
[0002] In the past, large volumes of beer for consumption have been stored, shipped in and dispensed from metal kegs of closed or single entry design. In such a keg, a so-called Sanke system is nearly-universally employed for regulating the flow of beer into and from the keg. A Sanke system comprises a spear tube and a valve of the type that includes inner and outer valved chambers to accommodate flows of pressurizing gas and of liquid responsive to the force exerted by such pressurizing gas.
[0003] Automatic washing and racking apparatus cleans, sterilizes and refills the combination of keg and valve. The reprocessing of such containers can be relatively expensive. However, the relatively substantial investment represented by such a system makes it mandatory to invest in such repeated processing.
[0004] Sanke-type valves commonly include apertures that permit the pressurized flow of beverage to impact the bottom of the (inverted) keg with great force during the filling or racking process. As a result, the beverage is substantially agitated and, in the case of beer, a substantial amount of foam or "head" is generated. As will be explained below, this head is quite undesirable in terms of both beverage waste and flavor.
[0005] Efforts to reduce cost have led to the development of plastic kegs for throw-away use. Such kegs are sold as a unit that includes a valve and beverage for picnic and related uses. The plastic keg is routinely of spherical design and includes a top, crimped to the mouth of the keg, that has a pair of flapper valves therein. One of such valves regulates a flow of pressurizing gas and the other regulates beverage flow. Unlike the metal kegs that include Sanke-type valves, plastic keg systems are filled with beverage prior to crimping the flapper valve top. As a result, anerobic bacteria often contaminate the beverage which results, in the case of beer, in an unsatisfactorily short shelf life.
[0006] The present invention addresses and overcomes the foregoing and additional shortcomings of the prior art by providing a new valve. In one embodiment the new valve includes a stationary outer cage. An inner cage is provided which is coaxial and movable with respect to the outer cage. The inner cage includes a substantially transverse deflector plate.
[0007] For a better understanding of the present invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:-
Figure 1 is a side sectional view of a valve, mounted to a receptacle, and shown in its closed filling configuration;
Figure 2 is a side sectional view of a valve including a filling head for urging the valve to an open filling configuration; and
Figure 3 is a sectional view of the valve taken along line 3-3 of Figure 1.
[0008] Turning now to the drawings, Figure 1 is a side sectional view of a valve 10 in accordance with one embodiment of the invention. As shown in Figure 1, the valve 10 is engaged to the mouth of an appropriate container or vessel 12. However, the invention may be adapted to numerous types of containers and beverages.
[0009] As shown in Figures 1 and 2, the valve 10 is illustrated in the inverted position that characterizes its attitude during the filling process. This process will be discussed in greater detail below. A significant utility and advantage of the present invention resides in the manner in which the filling process, utilizing conventional filling apparatus and techniques, is enhanc ed.
[0010] Returning now to Figure 1, the valve 10 can be seen to be sealably secured to the inner side of the mouth 14 of the container 10 by means of an O-ring 16. The ring 16 is seated within a circumferential notch in an outer cage portion 18 of the valve 10. The outer cage 18 is preferably formed of one of a number of appropriate, non-contaminating plastics such as those marketed under the trademarks "Lexann" or "PETG". Throughout the description of the valve 10 that follows reference will be made to valve elements of plastic composition and, unless otherwise noted, materials of the above-reference character and quality may be assumed as representative and appropriate compositions.
[0011] The outer cage 18 has a half-closed cylindrical shape that includes a plurality of apertures 20, 22, 24 and 26, the latter two of which are indicated only in Figure 3, a sectional view taken along the line 3 - 3 of Figure 1. Each of the apertures is oriented lengthwise in the cylindrical surface of the outer cage 18. As will be discussed below, the tapered apertures provide clearance for the tab-like transverse extensions of a deflector plate 28 that is integral, and therefore movable with, an inner cage 30. The lengthwise apertures of the outer cage 18 permit the cooperative movement of the valve elements. As will be discussed below, the design of the valve 10 effectively prevents the undesired spraying of liquid toward and against the bottom of the inverted container 12 when the valve is urged or moved to the open position during the filling process. The occurrence of such vertical spraying would, in the case of beer, waste and seriously degrade the quality of the product.
[0012] An aperture 32 in the top of the outer cage 18 provides clearance between it and a down tube 34. The down tube 34, which is preferably of compatible plastic composition, provides a conduit for pressurized backfill gas whose flow may be automatically monitored at a conventional fill stand. After the keg has been filled, the liquid within the keg is forced upward through the tube 34.
[0013] The length of the tube 34 is chosen in accordance with the depth of the container 12. It is fixed to, and therefore movable with, the inner cage 30 of the valve 10. An interference fit between the tube 34 and the lower end 36 of the inner cage 30 secures this relationship.
[0014] The inner cage 30 is preferably a molded plastic piece. As mentioned above, this element of the valve 10 is movable with respect to the outer cage 18 and induces lengthwise movement of the tube 34 through the clearance provided by the aperture 32 in the top of the outer cage 18.
[0015] An outer spring 38, which abuts the inner cage 30 adjacent the base of the transversely-oriented deflector plate 28, urges the inner cage to the "closed" configuration of Figures 1. As will be seen in Figure 2, by inserting a filling head, the force of the spring 38 is counteracted, permitting an "open" relationship between the inner and outer cages that allows the container to be filled.
[0016] The valve 10 is designed, in accordance with the general configuration and operation of Sanke-type systems, to seal (closed position) and to permit flows into the container 12 through the apertures in the side of the stationary outer cage 18 and out of the container 12 through the down tube 34 and the chamber within the inner cage 30 (open position). The valve 10 is urged to a closed configuration by the outer spring 38, which closes the path of fluid flow into the container 12 through the apertures of the outer cage 18, and an inner spring 40 that abuts the interior of the inner cage 30 and exerts a downward force upon a semi-spherical inner valve 42. As will be seen, the flow paths mentioned above are commonly opened by the insertion of a filling head or a conventional keg tap.
[0017] The inner valve 42 is preferably formed of rubber or the synthetic elastomeric material that is commercially available under the tr ademarks "EPDM" and Buna-N. The valve 12 may be of a moulded rubber composition. The lower end of the spring 40 is integral with (moulded into) the valve 42. By forming the spring 40-and- valve 42 as a single element, a greater degree of positive control is attained over the opening and closing movement of the valve 42. This is in contrast to prior art valves wherein an independent spring abuts a spherical valve. It is often difficult to maintain the desired alignment of the spring in such a case. The bottom of the spring may contact the spherical upper surface of the valve in such a manner as to exert undesired torquing force that destroys the desired spring alignment. This can lead to valve failure as the spherical valve may thereafter be urged by the misaligned spring to a nonfunctional orientation.
[0018] The valve 42 is urged by the spring 40 into an abutting relationship with an encircling valve seal that includes a plastic inner portion 44 and an outer portion 46 of rubber, EPDM or like synthetic elastomeric composition. The inner portion 44 of the valve seal is preferably fixed to the inner cage 30 by an acoustic weld 48. As will be seen in following discussions, the inner valve 42 is opened by combination of the counteracting forces of a filling head and the outer spring 38 that effect the inward movement of the spherical valve 42 relative to the surrounding inner cage 30 and valve seal. The particular compositions and design employed with regard to the inner seal differ from those of the prior art which employ a metal spherical valve in abutting relationship to a rubber valve seal. By choosing the semi-spherical valve 42 to be of rubber or like synthetic composition, the inner portion 44 of the valve seal is formed of appropriate composition for acoustic welding, an economical and advantageous process of manufacture, to the inner cage 30.
[0019] The outer portion 46 of the inner valve seal abuts, under the force applied by the outer spring 38, an encircling valve body 50 formed of compatible plastic composition. The valve body 50 is fixed to the outer cage 18 by means of an acoustic weld 52. The relationship between the upper portion 46 of the inner valve seal and the valve body 50 defines the fluid flow path into the container 12 through the apertures in the outer cage 18. As will be seen below, this flow path is opened by the force exerted by a recessed flange or collar of a conventional filling head which counteracts the closing force exerted by the outer spring 38.
[0020] A lug ring 56, fixed to the body 50 by means of an acoustic weld 58, provides a means for attaching a conventional tapping apparatus to the container 12. Any conventional apparatus may be conveniently fixed to the valve 10 for operation as a dispenser. The ring 56 is also designed with regard to conventional apparatus for filling a container 12 whereby the required access of the filling head, as shown in Figure 2, is assured.
[0021] Figure 2 is a side sectional view of the valve of the invention in its open configuration. The valve 10 has been urged to this open position, whereby fluids (gases and liquids) can flow through the longitudinal apertures in the outer cage 18 and through the inner valve 42 by the insertion of a filling head 62 of conventional design. The filling head 62 terminates in a truncated cone 64 that includes a plurality of orifices 66. The cone 64 is integral with a circular flange 68 and the inner diameter of the valve seal is preferably no greater than that of the base of the cone 64. By employing such relative dimensions, the filling head 62 may be inserted into the valve 10 substantially as shown in Figure 2. As can be seen from this figure, the insertion of the head 62 opens both the inner valve 42 and the "outer valve" (i.e. the chamber of the valve 10 that lies between the inner cage 30 and the outer cage 18.) The former portion of the valve 10 is opened by the pressure or force exerted by the truncated cone 64 against the inner v alve 42 while the latter portion is opened by the force of the circular flange 68 of the head 62 against the upper portion 46 of the valve seal.
[0022] The filling head 62 is part of conventional keg washer-racker apparatus that is capable of automatically performing a number of conventional processes including washing, sterilizing and filling a keg with beer or the like. As the present invention is compatible with either a throwaway plastic container or a reusable metal container, the cycle and number of operations performed in the filling/refilling operation is variable. However, the valve 10 is fully compatible with a conventional automatic washer-racker apparatus, whatever its selected cycle of operation.
[0023] Commercially available washer-racker systems include machines manufactured and sold under the trademarks "Centrimatic", "BRT 2", "Minipak" and "Centripak" by APV Burnett & Rolfe Ltd. of the United Kingdom. Such machines normally include both a washing head and a racking or filling head. In the event that a keg is to be recycled, it is first run through a cleaning and sterilization cycle on the washing head. The keg, including valve 10, is then moved to the filling head and installed as shown in Figure 2 (i.e. inverted). A conventional filling or racking cycle is then performed that may include steaming the keg or container to a set temperature and maintaining such temperature for a predetermined time period; introducing carbon dioxide gas into the container (through the outer valve) to purge the steam (through the inner valve) and condensate; building up a pre-set back pressure within the container 12; and then filling the container with liquid.
[0024] Referring back to Figure 2, numeral 70 indicates the direction of flow into the container 12 from a racking or filling machine as described above. As is seen, the beer or other liquid enters the container through the outer valve. That is, it enters through the apertures in the outer cage 18.
[0025] After an appropriate level of back or counter pressure is reached in the container 12 and filling has begun, apparatus within the racker permits a controlled flow of pressurized gas from its interior which is sensed by the racker. The purpose of the counter pressure is to suppress the buildup of foam or "head" that normally occurs when beer or a carbonated beverage is agitated. The gaseous outflow (whose path is indicated at 72) is anaylzed by a conductivity probe associated with the automatic racking machinery. The probe, which is arranged to detect the presence of liquid - as opposed to gaseous-flow in the down tube 34, actuates valving which turns off the beverage input. The probe cannot detect the presence of commingled liquid when a foam or head "mixture" is output from the container; rather, this fluid flow is sensed as gaseous.
[0026] Foam generated during the filling process thus represents a waste of beverage and cannot be recycled. Further, it has been found that, when a significant amount of foam is generated, the carbon dioxide backpressure can "drive" the gaseous head into the beer, degrading the taste of the product.
[0027] In the present invention, the harmful effects that result from the buildup of undesirable head during the filling or racking process are minimized by providing a design that minimizes the amount of turbulence or agitation that is encountered by the beverage during the filling process. In a conventional Sanke-type valve, beer (which enters under pressure from the racking machine) is free to travel and exit along the direction of the axis of the valve and may impact the bottom of the inverted keg with significant force. Further agitation, of course, occurs as the beer is pulled to the top of the inverted keg by gravity. Significant agitation does not subside until the beer has filled the container to the point that the apertures through which the pressurized liquid exits the valve are thoroughly submerged. This can, of course, result in the generati r buildup of a large amount of undesirable head each time a keg is filled.
[0028] In a valve 10 in accordance with this invention, the amount of head that is built up during the racking process is predictably minimized by a design that minimizes the agitation of the beverage as it is input by means of a conventional automatic racking or filling machine of the type described above. Prior reference has been made to the deflector plate 28 that is formed integrally with and transverse to the axis 74 of the inner cage 30. The plate 28 acts to prevent the vertical flow of the pressurized liquid beverage input through the valve 10, deflecting its path so that it will not impact the interior of the container 12 with significant momentum.
[0029] As is seen in Figure 2, the plate 28 causes the incoming liquid to flow radially through the apertures 20 through 26 in the side of the outer cage 18. By causing such redirection of the flow 72, the agitation of the liquid in minimized. A number of factors account for this beneficial effect. First, the beverage travels a shorter distance, building up less velocity and momentum, before striking an interior portion of the container 12. Secondly, the deflector plate 28 tends to dissipate the energy of the pressurized beverage flow, further lessening the impact force of the beverage against the container 12. Thirdly, the plate 28 redirects the flow 72 in such a way that it impacts the interior of the container 28 at glancing angles that generate less turbulence and agitation than normal impacts.
[0030] As mentioned above, it is highly desirable to interrupt the vertical flow of the input pressurized beverage. While the deflector plate 28 is provided to effect this beneficial result, means are additionally provided in this invention to assure that the tolerances required to permit the inner cage 30 to move with respect to the stationary outer cage 18 do not allow significant vertical "leakage" during the filling or racking operation.
[0031] Figure 3 is a sectional view of the valve of the invention taken along the line 3-3 of Figure 1. This view looks toward the down tube 34 from the interior of the inner cage 30. As seen in the figure, the circumference of the deflector plate 28 includes integral tab extensions 76, 78, 80 and 82 which alternate with recessed portions 84, 86, 88 and 90. The tabs are in registration with the longitudinal apertures 20 through 26 in the wall of the outer cage 18.
[0032] Small separation distances denoted "A" represent the gaps between the interior of the outer cage 18 and the deflection plate. Pressurized beverages entering the system must pass through either the small aperture 32 or the apertures in the side of the outer cage 18 (after flowing around the tabs of the deflector plate 28) without diversion to a radial path in order to travel vertically and impact the interior of the keg 12 with great force. As set forth above, the geometry of the valve 10 assures that one of a number of tortuous flow paths, each offering a minimal probability of "success", must be traversed to achieve this highly undesirable result.
[0033] A plurality of generally pie shaped pieces 92, 94, 96 and 98 is formed integrally with the upper surface of the deflection plate 28. As is most clearly shown in Figure 3, piece is aligned with and extends inwardly from a recessed portion of the circumference of the plate 28. The pieces 92 through 94 travel vertically adjacent the cylindrical wall of the valve 10 as it moves between the open and closed positions of Figures 1 and 2 to thereby stabilize the attitude of the inner cage 30 and associated deflector plate 28. Thus, undesired "cocking" of the inner cage 30 is prevented that could otherwise effect (i.e. increase) the separation distances indicated in Figure 3.
[0034] Thus, it is seen that the invention has provided a new and improved valve apparatus for use with a keg or like beverage container. The valve incorporates certain standard design features of a Sanke-type system whereby it can be utilized in conjunction with conventional washer-racker abd tapping apparatus. However, additional features are incorporated into the valve of the invention whereby the use and operation of this invention achieve economies that cannot be realized by the prior art.
[0035] The valve is fully compatible with popular spherical containers made of plastic that are particularly suitable for picnic and like use. Unlike prior art valve arrangements for use with such a container which employ a cap with flapper valves that is crimped onto the keg or other container after it is filled, the beverage is not exposed to anerobic bacteria that can limit shelf life. Further, the valve of the invention is fabricated substantially of plastic and elastomeric materials. Economy of fabrication is realized by such choice of materials and the use of relatively cheap acostic welding procedures. Thus, the valve of the invention provides the advantages of a Sanke-type system and offers sufficient economy of manufacture so that the combination container-with-valve unit needn't be reused to be economical. In this way, the costs of recycling expensive metal containers are avoided. Further, the welds of the valve discourage tampering with the contents of the container and the valve.
[0036] In addition to providing an economical apparatus, design features incorporated into the valve provide economies of use that are not realized in the prior art. By providing a deflection plate for diverting the incoming stream of pressurized liquid, the amount of agitation encountered during the filling process is minimized. As discussed in the description, this results in the minimization of the amount of foam or head generated, minimizing the attendant loss of beverage and the loss of quality that can result from the effects of the interaction of the head with the carbon dioxide back pressure.
1. A valve for a container comprising, in combination:
a) a stationary outer cage;
b) an inner cage, said inner cage being coaxial and movable with respect to said outer cage; and
c) said inner cage including a substantially transverse deflector plate.
2. A valve as defined in Claim 1 wherein the outer cage includes at least one lengthwise
aperture.
3. A valve as defined in Claim 2 in which
a) said deflector plate includes at least one peripheral tab; and
b) said plate is arranged so that said tab is movable within an aperture in said outer cage.
4. A valve as defined in 1,2 or 3 wherein said deflector plate additionally includes
a plurality of elements arranged adjacent preselected peripheral areas for guiding
said inner cage.
5. A valve as defined in Claim 1,2,3 or 4 wherein
a) a semi-spherical valve is located within said inner cage;
b) a spring is located within said inner cage for urging said semi-spherical valve to a predetermined position;
c) said spring is coaxial with the inner cage; and
d) said semi-spherical valve and said spring form a unitary piece.
6. A valve as defined in Claim 5 wherein said semi-spherical valve is formed of a
moulded rubber composition.
7. A valve as defined in any preceding wherein said inner cage and said outer cage
are plastic.
8. A valve as defined in any preceding claim wherein a spring mutually contacts the
inner surface of said outer cage and the outer surface of said inner cage adjacent
said deflector plate.
9. A valve as defined in any preceding claim further comprising a plastic down tube
fixed to said inner cage by means of an interference fit.