Abstract:
A flow control device for use in a supply line between a pressurised liquid container and a dispenser for the liquid. The flow control device comprises a chamber having an inlet for receiving liquid from the container and a base section comprising a chamber outlet for supplying liquid to the dispenser. A vent valve is included for venting gas from the chamber. A float valve includes a float section and a seat section and is movable to and from an open position wherein the chamber outlet is open to liquid flow and a closed position wherein the chamber outlet is closed to liquid flow. A float valve opening mechanism is included wherein the float section of the float valve comprises a plurality of protrusions, at least some of which engage the inside of the chamber so as to locate the float valve substantially in line with the chamber outlet. In this way, the float valve can guide itself into the correct position without the need for additional guiding components.

Description:
[0001]    The present invention relates to a flow control device for use in a supply line between a pressurised liquid container and a dispenser for the liquid, the flow control device comprising a chamber having an inlet for receiving liquid from the container; a base section comprising a chamber outlet for supplying liquid to the dispenser; a vent valve for venting gas from the chamber; a float valve comprising a float section and a seat section and movable to and from an open position wherein the chamber outlet is open to liquid flow and a closed position wherein the chamber outlet is closed to liquid flow; and a float valve opening mechanism. 
         [0002]    It is common for draught beer to be supplied from pressurised kegs to the taps at a bar using a pressurised gas. In this way, the pressurised gas effectively pushes the beer from the keg to the tap, through the supply line. However, as a keg empties and there is only a small amount of liquid left in the keg, the pressurised gas is known to create a foam from the remaining liquid. This foam then enters the supply line and will eventually reach the taps. This is undesirable as the foam or froth cannot be served to customers and must therefore be discarded, resulting in wastage and a decrease in profitability. Additionally, all the foam must be drained from the supply line when a new, full keg is fitted, thereby resulting in more wastage and also a delay in serving customers. Finally, the presence of foam in the supply lines can reduce the overall hygiene of the system. 
         [0003]    In order to overcome these problems, the Foam On Beer (FOB) detector was developed comprising a chamber having a beer inlet and a beer outlet, fitted with a float valve. When the chamber is full of beer, the float valve floats in the liquid, thereby leaving the beer valve open and supplying beer to the taps. However, when foam or froth begins to develop in the chamber, the float valve is too heavy and will not float on the froth. It will consequently sink down to the beer outlet, closing it off and preventing the foam from entering the supply lines. Such a FOB detector is disclosed in International Patent Publication No. WO 97/4123. 
         [0004]    There are a number of problems with the known FOBs. It is common to provide guide pins within the chamber to guide the float valve towards the beer outlet. International Patent Publication No. WO 97/4123 comprises bolts which hold the top and base of the chamber together. These bolts are accommodated in through-bores in the float valve such that the float valve is guided in its movement by the bolts and thus ensuring reliable operation of the float valve. Such bolts, guide pins, guide screws and their manner of engagement with the float valve, such as bores or recesses, provide breeding grounds for bacteria which can compromise the hygiene of the complete beer supply system. Additionally such components render the cleaning process for the FOB more complicated and often, less effective. 
         [0005]    It is an object therefore of the present invention to provide a flow control device that provides for a more hygienic system. 
       STATEMENTS OF INVENTION 
       [0006]    According to the invention there is provided flow control device for use in a supply line between a pressurised liquid container and a dispenser for the liquid, the flow control device comprising a chamber having an inlet for receiving liquid from the container; a base section comprising a chamber outlet for supplying liquid to the dispenser; a vent valve for venting gas from the chamber; a float valve comprising a float section and a seat section and movable to and from an open position wherein the chamber outlet is open to liquid flow and a closed position wherein the chamber outlet is closed to liquid flow; and a float valve opening mechanism characterised in that the float section of the float valve comprises a plurality of protrusions, at least some of which engage the inside of the chamber so as to locate the float valve substantially in line with the chamber outlet. 
         [0007]    In this way, the float valve is guided into the correct location in the outlet by its own protrusions and therefore the flow control device does not require any further components in order to guide the float valve into the correct location in the chamber outlet to close off the flow of liquid from the chamber. This reduces the number of components and associated engagement pieces such as bores, recesses, screw-threads and the like within the chamber. This in turn facilitates an increase in hygiene within the FOB by reducing the number of areas where bacteria can accumulate and further makes the FOB easier to clean. Additionally, there remains space surrounding the float valve through which the beer may flow. 
         [0008]    In one embodiment of the invention there is provided a flow control device in which the protrusions are substantially equidistant from each other. This is a particularly efficient manner of providing the protrusions, ensuring substantially uniform guiding irrespective of the revolution of the float valve about the axis of the chamber. 
         [0009]    In another embodiment of the invention there is provided a flow control device in which the float section substantially comprises a right prism having a plurality of side edges. This is a particularly effective way of providing a float valve wherein the side edges of the prism provide the protrusions, while also providing a body to provide the floatation necessary for the operation of the float valve. 
         [0010]    In a further embodiment of the invention there is provided a flow control device in which the side edges of the prism form the protrusions for engagement with the inside of the chamber. This is a particularly efficient method of providing the protrusions of the float valve. 
         [0011]    In an alternative embodiment of the invention there is provided a flow control device in which the faces of the prism are concave. In this way, the cross-sectional area and consequently the volume of the float valve is reduced, while still allowing the protrusions thereof to engage the inner wall of the chamber, thereby providing for improved flow of beer passed the float valve. 
         [0012]    In an embodiment of the invention there is provided a flow control device in which the chamber outlet is located centrally within the base section and the protrusions on the float section of the float valve act to locate the float valve centrally within the chamber. This is a particularly efficient embodiment of the flow control of the device, facilitating a regularly shaped float valve. 
         [0013]    In an embodiment of the invention there is provided a flow control device in which the chamber is defined by the base section, a top section and at least one wall connected therebetween. This is a particularly efficient manner of providing the chamber of the invention. Preferably, the wall is a hollow cylindrical wall. 
         [0014]    In one embodiment of the invention there is provided a flow control device in which the seat section of the float valve is adapted to engage the chamber outlet. In this way, the float valve will operate to close off the chamber outlet when there is no liquid within the chamber to cause the float valve to float. 
         [0015]    In another embodiment of the invention there is provided a flow control device in which the vent valve is mounted in the top section. In this way, the vent valve is not in the path of the liquid within the chamber and the liquid will not in general come into contact with the vent valve. Therefore, any bacteria present in the vent valve have a reduced chance of contaminating the liquid in the chamber. 
         [0016]    In a further embodiment of the invention there is provided a flow control device in which the vent valve is rotatably mounted in the top section. In this way, the vent valve may be rotated as necessary to facilitate the installation of a suitable vent line thereto. 
     
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
         [0017]    The invention will now be more clearly understood from the following description of an embodiment thereof given by way of example only with reference to the accompanying drawings in which:— 
           [0018]      FIG. 1  is an exploded view of the device according to the invention; 
           [0019]      FIG. 2  is a perspective view of the device according to the invention; 
           [0020]      FIGS. 3(   a ), ( b ) and ( c ) are side, perspective and top views, respectively, of the float valve; 
           [0021]      FIG. 4  is a detail cross-section view of a portion of the device showing the inlet and outlet; 
           [0022]      FIG. 5  is a detail cross-section view of a portion of the device, including the vent valve; and 
           [0023]      FIG. 6  a detail cross-section view of a portion of the device showing the float lifter 
       
    
    
       [0024]    Referring to the drawings, and initially to  FIG. 1  thereof, there is shown a flow control device indicated generally by the reference numeral  1 , comprising a substantially cylindrical base section  102 , a substantially cylindrical tube forming a wall  104 , a float valve  106 , a top section  108  and a vent valve  110 . The wall  104 , the base section  102  and the top section  108  together form a chamber for the reception of liquid from a pressurised container (not shown). 
         [0025]    The base section  102  comprises a substantially solid, cylindrical lower portion  112  having a number of apertures formed therein. The apertures comprise a circular blind hole which extends downwardly from the centre of the upper surface of the lower portion  112 , forming the chamber outlet  122 ; a vertical throughhole offset from the centre of the base section  102 , and separate from the chamber outlet, forming the inlet  114 ; and a horizontal aperture, forming an outlet channel  116 , which extends from the side of the lower portion  112  of the base section  102  to the centre of the base section  102  where it joins the chamber outlet  122 . The base section further comprises an additional aperture, substantially orthogonal to the chamber outlet  122  and the outlet channel  116 , that extends substantially horizontally from the side of the lower portion  112  of the base section  102  to the centre of the base section  102  forming a channel  118  for the float lifter  120 . The channel  118  meets the outlet channel  116  and the chamber outlet  122 . The chamber outlet  122  comprises a downward inwardly tapering section ending in a right cylindrical section (not shown), which is in communication with the outlet channel  116 . The upper surface of the lower portion  112  of the base section  102  mounts a circular threaded flange  124  which is concentric with the base section and inwardly offset from the side of the lower portion  112  of the base section  102 . Finally, mounted to the side of the base section  102  is a rectangular bracket  126  for mounting the device  1  on a wall (not shown) or other suitable support. 
         [0026]    The float lifter  120 , which operates as a float valve opening mechanism, comprises an elongate cylindrical body  128  dimensioned to rotatably and closely engage the channel  118  in the base section  102 . One end of the cylindrical body  128  mounts an orthogonally projecting handle  130  to facilitate rotation of the float lifter  120 , while the opposite end of the cylindrical body  120  mounts a curved shelf  132  projecting forwardly from the end of the cylindrical body  120 , in line with the handle  130 . 
         [0027]    An inlet tube  134  is fitted to into the inlet  114  and projects upwardly from the base section  102  of the device  1 . The wall  104  engages the base section and encloses the inlet tube  134 . The wall  104  comprises an elongate hollow cylindrical section having an outer surface  136  and an inner surface  138 . Adjacent each end of the wall  104 , the inner surface supports a groove  140  for reception of a rubber O-ring (not shown) and a thread (not shown), for engagement with the threaded flange  124  on the base section  102  and a further thread (not shown) on the top section  108 . 
         [0028]    The float valve  106  comprises a float section  142  which tapers into a seat section  146 . The float section  142  comprises a right triangular prism having substantially concave faces, such that the side edges of the prism form protrusions  143  for engagement with the inner surface  138  of the wall  104 . The horizontal cross section of the float section  142  takes the form of a concave equilateral hexagon, wherein the hexagon comprises three convex apexes alternated with three concave apexes. The convex apexes correspond to the side edges of the prism and form the protrusions  143 . The seat section  146  comprises a right cylindrical section that is narrow with respect to the float section  142 , and is dimensioned to engage the chamber outlet  122  in a snug manner. 
         [0029]    The top section  108  of the device comprises a solid, substantially cylindrical body  148  having a vertical throughhole  150  formed along its central axis and a laterally projecting lip  152  adjacent the top of the body  148 . A thread (not shown) is formed on the outside surface of the cylindrical body below the lip  152 . 
         [0030]    The vent valve  110  comprises an upright vent body  154  having a vent tube  156  projecting orthogonally therefrom and in communication therewith. A vent spindle  158  is inserted through the vent body  154  and fitted with a cap  160 . 
         [0031]    Referring now to  FIG. 2 , in which like parts have been given the same reference numerals as before, there is shown a perspective view of the assembled flow control device  1 . The vent valve  110  is inserted though the throughhole (not shown) in the top section  108 . The vent valve  110  is rotatable about its vertical axis. The top section  108  and the base section  102  have been attached to the wall  104 , forming a chamber  200  for the reception of fluid. The float lifter  120 , with its handle  130 , is shown inserted into the float lifter channel  118  in the base section. The base section  102  further comprises the outlet channel  116 , and has the bracket  126  fitted thereto. 
         [0032]    Each aperture on the outside surface of the flow control device, namely the throughhole  150  in the top section  108 ; the float lifter channel  118  in the base section  102 ; the outlet channel  116  in the base section  102  and the inlet  114  in the base section are fitted with a push-fit collet  202 . During assembly of the flow control device, the collet  202  is loosely placed within the relevant aperture and the relevant fitting such as the vent valve or float lifter is then slotted into the aperture through the collet. The collet  202  is then pushed home by hand, securing the fitting in place. Subsequently, to remove the fitting, it suffices to hold the collet  202  in place by hand and the pull out the fitting, also by hand. Therefore, all the connections can be made without using tools, facilitating ease of installation and maintenance. 
         [0033]    Referring now to  FIGS. 3(   a ), ( b ) and ( c ), in which like parts have been given the same reference numerals as before, there is shown a side, perspective and top view respectively of the float valve  106 . The float valve  106  comprises the float section  142 , the seat section  146  and a narrow neck section  144  therebetween. The float section  142  comprises an upper float section  601  and a lower float section  603 . The upper float section  601  comprises the right triangular prism having substantially concave faces, as described in relation to  FIG. 1  above. The upper float section  601  therefore comprises the side edges of the prism that form the protrusions  143  for engagement with the inner surface  138  of the wall  104 . The horizontal cross section of the upper float section  601  takes the form of a concave equilateral hexagon, wherein the hexagon comprises three convex apexes alternated with three concave apexes. The convex apexes correspond to the side edges of the prism and form the protrusions  143 . The lower float section  603  comprises the section of the float valve  106  that tapers from the upper float section  601  to a point where the float valve narrows into the neck section  144 . In the lower float section  603 , the side edges of the prism forming the float section  142  of the float valve  106  are sliced away such that edges become substantially triangular faces  605 , inclined inwardly and downwardly. The seat section  146  comprises a right cylindrical section that is narrow with respect to the float section  142 , but is wider than the neck section  144 . The seat section  146  is dimensioned to engage the chamber outlet  122  in a snug manner. The neck section  144  forms a groove for reception of a small O-ring (not shown) so that in combination, the seat section and small O-ring act to close the chamber outlet to fluid flow when the sect section  146  engages therewith. 
         [0034]    The top surface of the float valve  106  is slightly raised in the centre and slopes downwards therefrom. This facilitates the flow of liquid over the top of the float valve and ensures that no liquid will lie on the top of the float valve. This in turn ensures that the top of the float valve does not provide an area that would be difficult to clean or that would provide a location that would encourage the accumulation of bacteria. 
         [0035]    Referring now to  FIG. 4 , in which like parts have been given the same reference numerals as before, there is shown a cross-section detail of the lower part of the flow control device  1 . There is shown the horizontal aperture in the side of the lower portion  112  forming the outlet channel  116  of the flow control device  1 . There is further shown the chamber outlet  122  extending downwardly from the centre of the surface of the lower portion  112  of the base section  102 . The vertical chamber outlet  122  and the horizontal outlet channel  116  intersect thereby providing a path for liquid from the chamber  200  to exit the device  1 . The chamber outlet aperture comprises a downward, inwardly tapering section  308  which joins a cylindrical section  310 , which intersects with the aperture forming the outlet cannel  116 . 
         [0036]    There is further shown the inlet  114  extending vertically from the bottom of the base section  102  to the upper surface of the lower portion  112  of the base section  102  where is connects with the inlet tube  134  which extends upwardly into the chamber  200 . Finally, there is shown the cylindrical wall  104  engaging the threaded flange  124  which projects upwardly from the lower portion  112  of the base section  102 . A large O-ring  306  is positioned in a groove in the inner surface of the wall  104  where the wall  104  engages the threaded flange  124  of the base section  102 . The O-ring  306  provides a seal. 
         [0037]    The outlet channel  116  is fitted with a push-fit collet  202  which engages a collar  302  inserted into the aperture. Additionally, a pair of O-rings  304  are located within the outlet aperture  116  so as to form a seal. This arrangement of collet  202 , collar  302  and O-rings  304  is repeated for the aperture forming the inlet  114  at the bottom of the base section  102 . 
         [0038]    Referring now to  FIG. 5 , in which like parts have been given the same reference numerals as before, there is shown a cross-section detail of the upper part of the flow control device  1 . The vent valve  110  is fitted through the vertical, centrally located aperture in the top section  108  of the flow control device  1 . The throughhole  150  is fitted with a push-fit collet  202  which engages a collar  302  inserted into the throughhole  150 . Additionally, a pair of O-rings are located within the throughhole  150  so as to form a seal. The top section  108  itself engages the cylindrical wall  104  so as to seal the chamber  200 . A large O-ring  306  is positioned in a groove in the inner surface of the wall  104  where the wall engages the thread (not shown) on the outside surface of the cylindrical body  148  of the top section  108 . The vent valve  110  comprises a hollow, upright vent body  154  having a hollow vent tube  156  projecting orthogonally therefrom such the hollow sections of the vent body  154  and vent tube  156  are in communication; a vent spindle  158  inserted through the vent body  154 , extending beyond the vent body at each end thereof and engaging a cap at its top end. The vent body is rotatable by 360°in the throughhole  150  but is otherwise fixed in place and does not move longitudinally. The vent spindle comprises an elongate substantially cylindrical body having a number of sections. The lowest section, forming the bottom of the vent spindle  158 , comprises a thin, cylindrical lip section  402  above which is a first recessed section  404  of narrower diameter than the lip section. The first recessed section  404  is fitted with an O-ring  406  so as to provide a seal at the base of the throughhole  150 . Above the first recessed section  404  is a wide cylindrical section  408 , having the same diameter than the lip section. The wide cylindrical section  408  joins a tapering section  410  which tapers inwardly to an elongate, narrow cylindrical section  412 , having a diameter less than that of the wide cylindrical section  408  but greater than that of the first recessed section. Above the narrow cylindrical section  412  is a second recessed section  414  which has a diameter less that the diameter of the first recessed section  404 . The second recessed section  414  is fitted with an O-ring  416  which engages the inside of the vent body  154 . Finally, above the second recessed section  414  is a top cylindrical section  416  which terminates in a narrow threaded section  418 . A helical spring  420  is placed over the top cylindrical section such that it abuts against the top of the vent body  154 . The spring is not wide enough to pass over the vent body. The cap  160  is fitted over the spring  420  and a thread (not shown) internal to the cap engages the threaded section  418  of the vent spindle  158 , securing the cap  160  in place. The length of the vent spindle  158  is substantially equal to the combination of the height of the vent body  154  combined with the length of the cap  160 . 
         [0039]    In use, the vent valve  110  is held in a closed position as illustrated wherein the O-ring  406  fitted at the first recessed section  404  of the vent spindle  158  abuts the base of the throughhole  150  in the top section  108 , thereby preventing gas or liquid from escaping via the throughhole  150 . The vent spindle  158  is held in this closed position as its top end is attached to the cap  160  which is spaced apart, and biased away, from the vent body by the spring  420 . The vent valve  110  is operated by pressing down on the cap  160  such that the spring  420 , which rests on the top of the vent body, is compressed. Pressing down on the cap moves the vent spindle downwards through the vent body such that the tapering section  410  of the vent spindle is adjacent the base of the throughhole  150 . In this way, there will be a pathway between the base of the throughhole  150  and the vent tube  156 , thereby providing a pathway for gas and liquid from the inside of the chamber  200  to the outside of the device. 
         [0040]    Referring now to  FIG. 6 , in which like parts have been given the same reference numerals as before, there is shown a cross-section detail of the lower part of the flow control device  1  comprising the base section  102  and the float lifter  120 . The cross-section of  FIG. 6  is taken along a line orthogonal to the line along which the cross-section of  FIG. 4  is taken. The float lifter  120  comprises an elongate cylindrical body  128  which engages the float lifter channel  118  in the base section  102 . The float lifter body  128  is dimensioned so as to be snugly rotatable within the channel. The float lifter is secured in place in the channel by way of the collet  202 , collar  302  and O-ring assembly as used in the other apertures in the top section  108  and base section  102 . The float lifter  120  further comprises a handle  130  projecting orthogonally from the float lifter body  128  adjacent one end thereof, and a curved shelf  132  projecting forwardly from the opposite end of the float lifter body  128 . The float lifter  120  extends along the channel  118  into the base section  102  such that the shelf  132  will rest directly below the chamber outlet  122 . 
         [0041]    In use, the flow control device  1  is positioned in the supply line for a pressurised system between a container (not shown) for a liquid and the dispenser (not shown) for the liquid. A pipe (not shown) from the container is connected to the inlet  114  and a further pipe (not shown) is connected from the outlet to the dispenser. The vent valve  110  is operated, by pressing down on the cap  160 , such that there is an escape path for the air in the chamber  200 , allowing the chamber to fill with liquid from the pressurised supply line. The liquid will then enter the flow control device through the inlet  114  and pass up the inlet tube  134  into the chamber  200 . As the chamber  200  fills with liquid, the float valve  106  will begin to float in the liquid, moving away from its seat position in the chamber outlet  122 , thereby allowing the liquid to flow down through the chamber outlet valve and out of the flow control device through the outlet channel  116 . However, as the level of liquid left in the container reduces and approaches emptiness, the gas used in the supply line will begin to cause the liquid to foam or froth. The level of liquid in the chamber  200  will drop as the froth is generated. As the liquid level drops, so does the float valve  106 , as it will not float on the froth. As the float valve  106  drops, it will be guided into the correct position relative to the chamber outlet  122  by the protrusions  143 . The diameter of the circumcircle of the cross section of the upper float section  601  of the float valve is slightly less than the inner diameter of the chamber. In this way, the float valve can only move slightly away from the central axis of the chamber before the protrusions abut against the inner surface of the wall  104 . Additionally, the depth of the float valve  106  prevents it from flipping in the chamber ensuring that the seat section  146  will always be facing towards the chamber outlet  122 . Therefore, as the liquid level in the chamber  200  drops, with float valve  106  will also drop until the seat section  146  of the float valve  106  engages the chamber outlet aperture  122 , closing it off and preventing any further flow of liquid or foam from the chamber  200 . Once the empty container has been replaced with a full one, the flow control device  1  can be reset by pressing on the cap  160  of the vent valve  110  so that the liquid can once again fill the chamber  200 . If the float valve  106  does not immediately lift, it may be necessary to operate the float valve opening mechanism, in this case the float lifter  120 , by rotating the float lifter body  128  using the handle  130 . This causes the shelf  132  to unseat the seat section  146  of the float valve  106 . The float valve  106  will then re-float itself and the flow control device  1  operates as described. The float lifter  120  will also be raised during the clean of the supply line so as to allow the detergents that are passed through the system to access all areas of the base section  102  of the flow control device  1 . 
         [0042]    It will be understood by the person skilled in the art that the flow control device is preferably for use in a draught beer supply line, for example, in a bar or restaurant, but that it is not limited to that particular usage. Preferably, the base section and top section are manufactured from precision machined, food grade stainless steel, while the wall  104  is preferably manufactured from polymethymethacrylat, more commonly known as sight glass. The O-ring seals used throughout are of food grade quality and the float valve is preferably manufactured from polypropylene. It will be further understood that the float valve must be manufactured from a material that will be of a suitable density to allow it to float in the liquid used in the system. 
         [0043]    In the specification the terms ‘comprise’, ‘comprises’, ‘comprised’ and ‘comprising’ or any variation thereof and the terms ‘include’, ‘includes’, ‘included’ or ‘including’ or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation. 
         [0044]    The invention is not limited to the embodiment herein described, but may be varied in both construction and detail within the terms of the claims.