Abstract:
A home beer dispensing apparatus has a keg having a self-contained bag filled with a beer and a pressure system. The pressure system creates a pressurized air space between the keg inner walls and the bag to assist in the dispensing of the beer. The pressure system has a keg one-way air valve mounted to a top wall of the keg to permit entry of pressurized air into the keg. The pressure system has a pressure reservoir mounted in the dispensing apparatus outside the keg and in fluid flow communication with the keg one-way valve. The reservoir stores a charge of pressurized air and supplies at least a portion of this charge to the keg through the keg air valve when the dispensing apparatus is operated to dispense the beer. The reservoir provides a reserved charge of pressurized gas that is on hand to reduce dampening pressure fluctuations during beer dispensing which can result in beer frothing, especially during the early stages of beer dispensing when the air head space in the keg is small. Further, the apparatus may also have a pressure sensing system adapted to measure time rate of pressure change in the keg. The apparatus has a signaling device responsive to the time rate of pressure change in the keg to produce a signal related to volume of beer remaining in the bag. Preferably, the signal is displayed visually on the dispensing apparatus.

Description:
The Applicants claim priority to International Application Number PCT/IB2003/005399, filed on Nov. 25, 2003, which claims priority to British Application Numbers GB 0227930.5 and 0227931.3, filed on Nov. 29, 2002. 
     FIELD OF THE INVENTION 
     The present invention relates to an alcohol beverage dispensing beverage apparatus having a pressure system for use in dispensing an alcohol beverage and in particular, relates to a home beer dispensing apparatus having a gas pressure reservoir. Further, it relates to an alcohol beverage dispensing apparatus having a pressure sensing system and in particular, relates to a home beer dispensing apparatus having a pressure sensing system that determines volume of beer remaining in the apparatus. 
     BACKGROUND OF THE INVENTION 
     Beer dispensing apparatus are known in the art for dispensing of draft beer in taverns and the like. Typically, the beer is dispensed from a keg under pressure from CO 2  tanks forming part of the pressure system. Such draft beer dispensers are utilized in taverns where the large volumes of beer are dispensed everyday and the taverns have refrigerated rooms to store the kegs. 
     This is not the case for a domestic or home beer dispensing apparatus that is adapted to sit on a countertop in a kitchen where space is at a premium. Further, the domestic beer dispensing system typically stores the beer in a bag contained in a keg and pressure is applied between the keg inner walls and the bag to assist in the dispensing of beer from the keg. 
     Due to limited countertop space requirements, there is a requirement in the home beer dispensing apparatus to reduce compressor size and still maintain sufficient pressure within the keg to properly effect the dispensing of beer from the keg. Further there is a need to provide sufficient pressure to reduce dampening pressure fluctuations during dispensing which can result in beer frothing, especially during the early stages of dispensing beverage where the head pressure in the keg is minimal. 
     Moreover, it is difficult to determine the volume of beer remaining in a home beer dispensing system utilizing a keg having a self-contained bag of beer. This is because the keg does not provide for a visual indication of the amount of beer left in the keg. Further, once the keg is placed inside the beer dispensing system, it is no longer readily accessible to the consumer. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an alcohol beverage dispenser wherein sufficient pressure is maintained to reduce dampening pressure fluctuations during alcohol dispensing, especially during the early stages of alcohol dispensing. 
     It is a further object of the present invention to provide an alcohol beverage dispensing apparatus which reduces compressor rating. 
     It is a further object of the present invention to provide an alcohol beverage dispenser having a keg with a self-contained bag containing the beverage where the apparatus produces a signal indicative of the volume of beer remaining in the bag. 
     The present invention relates to an alcohol beverage dispensing apparatus comprising a keg having a self-contained bag filled with an alcohol beverage. Preferably, the beverage is beer. The dispensing apparatus has a pressure system adapted to maintain a gas pressure in the keg against the bag to assist in the dispensing of the beverage from the dispensing apparatus. The pressure system has a pressure reservoir that stores a charge of pressurized gas which is preferably air. The reservoir is mounted in the apparatus outside the keg and in fluid flow communication with the interior of the keg. The reservoir is adapted to transmit at least a portion of its charge of pressurized gas into the keg when the dispensing apparatus is operated to dispense the beverage. 
     By providing a reserved charge of pressurized gas, a sufficient supply of gas is on hand to reduce dampening pressure fluctuations during alcohol dispensing which can result in beer frothing, especially during the early stages of alcohol dispensing when the air head space in the keg is small. 
     Preferably, the pressure system has a gas compressor connected with the pressure reservoir for charging the pressure reservoir with pressurized gas prior to the dispensing apparatus being operated to dispense the beverage. Additionally, the compressor may continue to be operated to charge the reservoir during dispensing of the beverage from the dispensing apparatus and, if necessary, after the dispensing cycle is completed. The compressor continues to change the pressure in the reservoir until it reaches a predetermined pressure level. As a result, the compressor rating is reduced. 
     In a preferred embodiment, to economize on space requirements in the dispensing apparatus, where the keg has a curved side wall, the pressurized reservoir has a curved wall adapted to surround in adjacent relation at least a portion of a curved side wall of the keg. 
     Preferably, the pressure system comprises a pressure switch connected in fluid communication between the pressure reservoir and a gas valve in the keg. The pressure switch enables pressurized gas to flow from the reservoir into the keg through the keg gas valve when beverage is dispensed from the bag. It is envisaged that this switch may form part of the keg gas valve, may be part of an exit or exhaust valve for the reservoir, or may be in a tube or tap interconnecting the reservoir with the keg gas valve. 
     In a second embodiment, the apparatus has a pressure sensing system adapted to determine the time rate of pressure change in the keg. The apparatus has a signaling device responsive to the time rate of pressure change in the keg to produce a signal related to volume of beverage remaining in the bag. 
     Advantage is found with this embodiment of the present invention because during a normal beer dispense cycle, the time rate of change in pressure in the keg varies as the volume of beer in the keg diminishes. As a result this property of pressure change in the keg is utilized by the present invention to provide a signal indicative of the volume of beverage remaining in the keg. Preferably, the beverage is beer and the signal is displayed visually on a face of the dispensing apparatus. Alternatively, an audio signal may be generated. 
     In one preferred aspect of this embodiment of the present invention, the pressure sensing system measures time rate of change of pressure drop in the keg during a normal beverage dispense cycle and the signaling device in response to the time rate of pressure drop produces the signal relating to volume of beverage remaining in the bag. 
     In another preferred aspect of this embodiment of the present invention, the pressure sensing system measures time rate of change of pressure rise in the keg subsequent to a normal dispense cycle and the signaling device is responsive to the time rate of pressure rise to produce the signal relating to volume of beverage remaining in the bag. 
     Preferably, the pressure sensing system has first and second pressure sensors respectively for sensing higher and lower predetermined values of pressure in the keg and respectively generating first and second pressure signals. The pressure sensing system has a controller for determining the time interval between the generation of the first and second signals to determine either the time rate of pressure drop, or the time rate of pressure rise, in the keg. 
     Preferably, the first predetermined value of pressure is less than maximum pressure normally maintained in the keg by the pressure system and the second predetermined value of pressure is greater than minimum pressure reached in the keg during the normal dispense cycle. 
     Preferably, the first and second pressure sensors are mounted in the dispensing apparatus in pressure sensing contact with the keg outer wall to sense pressure on the keg that is related to the pressure in the keg. 
     In accordance with the first embodiment of the present invention there is provided an alcohol beverage dispensing apparatus comprising a keg having a self-contained bag filled with an alcohol beverage. The dispensing apparatus comprises a pressure system adapted to maintain a gas pressure in the keg against the bag to assist in the dispensing of the beverage from the dispensing apparatus. The pressure system comprises a keg gas valve mounted to the keg to permit entry of pressurized gas into the keg and a pressure reservoir mounted in the apparatus outside the keg. The reservoir is in fluid flow communication with the keg gas valve. The pressure reservoir stores a charge of pressurized gas and is adapted to supply at least a portion of the charge of pressurized gas into the keg through the keg gas valve when the dispensing apparatus is operated to dispense the beverage. 
     In accordance with the second embodiment of the present invention there is provided an alcohol beverage dispensing apparatus comprising a keg having a self-contained bag filled with an alcohol beverage. The apparatus comprises a pressure system adapted to maintain gas pressure in the keg against the bag to assist in the dispensing the beverage from the dispensing apparatus. The apparatus has a dispensing device adapted to dispense beer from the bag and lower gas pressure in the keg during a normal beverage dispense cycle. The apparatus has a pressure sensing system adapted to measure time rate of pressure change in the keg and a signaling device responsive to the time rate of pressure change in the keg to produce a signal related to volume of beverage remaining in the bag. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the nature and objects of the present invention reference may be had to the accompanying diagrammatic drawings in which: 
         FIG. 1  is a front elevation view of a home beer dispensing apparatus in accordance with the present invention; 
         FIG. 2  is a side elevation view of the home beer dispensing apparatus; 
         FIG. 3  is a side sectional view of the keg shown inside the beer dispensing apparatus of  FIG. 2  illustrating the pressurizing system of the present invention and the pressure sensing system of the present invention; 
         FIG. 4  is a perspective view of the interior of the home beer dispensing apparatus; 
         FIG. 5  is an exploded view of the component parts of the compressor and pressure reservoir utilized in the pressure system of the present invention; and, 
         FIG. 6  is a side sectional view of the compressor. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2  there is shown a home beer dispensing apparatus, appliance or unit  10 . The dispensing apparatus  10  is primarily intended for use in domestic kitchens but may also be used in utility rooms, garages, domestic bars, caravans etc. While the preferred embodiment relates to dispensing beer, alternatively carbonated solutions or other alcohol beverages may be dispensed by apparatus  10 . 
     The home beer dispensing apparatus  10  has a front wall  12  and a dispensing tap  14  protruding forward of the front wall  12 . A drip tray  16  also protrudes forward of the front wall  12  and is adapted to support an open glass container  18  below the dispensing tap  14 . The home beer dispensing apparatus  10  further has a base  21  adapted to rest on a counter top in a kitchen. The front wall  12  is formed as an extension of two pivoting side walls  20  which may be moved between closed and open positions to allow the keg  22  (see  FIG. 2  in broken lines) to be inserted into the housing of the home beer dispensing apparatus  10 . The housing of the home beer dispensing apparatus  10  further includes a top wall  24  and a rear wall  26 . The rear wall  26  has a grill  30  that permits for air circulation within the home beer dispensing apparatus  10 . An electrical cord  32  extends through the rear wall  26  of the apparatus  10  to provide a connection into a main electrical supply to supply electrical power to the electrical components housed within the dispensing apparatus  10 . Alternatively, a 12 Volt DC supply input may be used. 
     The dispensing apparatus  10  has a cooling system  23  located behind and below keg  22  that is adapted to cool the keg  22  of beer when placed in dispensing apparatus  10 . The dispensing apparatus  10  also dispenses the beer by providing a pressurized air supply  50 . 
     Referring to  FIGS. 2 ,  3  and  4 , cooling of the keg  22  within the beer dispensing apparatus  10  is accomplished by a cooling system  23  comprising cooling plate  70  in mechanical and heat transfer contacting relation with a bottom portion  44  of the keg  22  for extracting heat from the beer  52 . 
     The cooling apparatus further includes a Peltier thermoelectric device  80  mounted in mechanical and thermal heat transfer contacting relation with the cooling plate  70 . The Peltier thermoelectric device  80  is connected through a suitable leads and transformer  81  to the power supply line or cord  32  so that a voltage is applied across the Peltier thermoelectric device  80 . The voltage drop across this Peltier cooling device  80  results in a thermal difference being generated across the device whereby surface  82  of Peltier device  80  is cooler than hot surface  84 . As a consequence, heat is extracted from the cooling plate  70  which in turn extracts heat from the keg  22 . The Peltier thermoelectric device  80  provides a low rate of continuous cooling. Active heat extraction is provided by heat sink  33  and cooling fan  35 . 
     Referring to  FIG. 3 , the keg  22  of the present invention is shown in more detail. The keg  22  has a general cylindrical shape with side walls  40  and a top wall or top portion  42  and a bottom wall or bottom portion  44 . Both top wall  42  and bottom wall  44  are curved upwardly from the central portion of the keg  22  and are provided with a raised annular collar  46 . The collars  46  provide additional support for the keg  22 . Mounted within the keg walls  40 ,  42  and  44  is a plastic bag  55  for containing alcohol beverage which in the preferred embodiment is beer  52 . 
     As shown in  FIG. 3 , the bag  55  almost completely fills the keg  22  and an air head space  62  is present. This illustration represents a condition where some of the beer  52  has already been dispensed from bag  55  and the bag  60  is partially deflated and beer  52  is under pressure. Arrows  63  represent air pressure within keg  22  acting against bag  55  to facilitate dispensing of beer  52 . 
     It should be understood that initially the bag  55  lines the interior walls of keg  22  and is completely filled with beer  52  providing little or no head space  62 . As the beer  52  is dispensed from the keg  22 , an air pressure  63  is established between the walls of the bag  55  and the inside surfaces of walls  40 ,  42  and  44  of the keg. This head space  62  continues to grow as beer is dispensed until the beer is dispensed from bag  55 . 
     The top portion  42  and collar  46  located in the top portion  42  of keg  22  has a keg beer dispensing valve  60  extending through the top collar  46 . The valve  60  is connected to the tap  14  of the beer dispensing apparatus  10  by a tube or tap connection (not shown) extending from the keg dispensing device  60 . The dispensing device  60  has a hollow dip tube  66  that extends into the keg  22  within bag  55  so as to provide a remote opened end  64  adjacent the bottom portion  44  of the keg for drawing beer  52  from the keg adjacent the bottom portion  44  of the keg  22  as represented by arrows  45 . Beer  52  is drawn through opening  64 , up hollow tube  66 , and out through valve  60  to the tap  14  ( FIG. 1 ). 
     Referring to  FIGS. 3 and 4 , the air pressure as indicated by arrows  63  within the keg  22  is provided by the air pressure system  50 . The air pressure system  50  is shown to comprise a compressor or pump motor  90 , a pressure reservoir  92 , tubing or conduit  94 , a pressure switch  96 , and a one-way reed air valve  98 . 
     The air valve  98  is a one way air valve comprising a reed type valve which permits air to flow into the space  62  between the bag  55  and the interior walls of the keg  22 . This valve  98  is mounted to the keg and forms part of an over all valve system including the beverage dispensing valve  60 . The air valve  98  is located within the collar  46  of the keg in a standardized location. The valve combination  60  and  98  is mounted into the keg through the collar  46  by knocking out a face plate that otherwise extends across the collar  46 . The valves  60  and  98  are mounted in sealed relation with the keg  22 . The valve  98  is in fluid communication with the reservoir  92  by means of tubing  94  and pressure switch  96 . Tubing  94  may form part of the tap connection (not shown) which provides a standardized fitting on valves  60  and  98 . Pressure switch  96  may form part of the valve  98  or alternatively may form part of the exhaust valve or opening for the reservoir  92 . Pressure switch  96  is preferably activated by the activation of the dispensing tap  14  to draw beer  52  out through dispensing tube  66  and valve  60 . This is indicated graphically in  FIG. 3  by the broken line extending from switch  96  with an arrow pointing towards number  14  representative of tap  14 . 
     The reservoir  92  is located with its wall  100  located in abutting relation with an outside wall  40  of the keg  22 . As shown better in  FIG. 4 , the wall  100  of the air reservoir  92  is curved to follow and be adjacent to the curvature of the cylindrical wall  40  of the keg  22 . The placement of the reservoir  92  above the Peltier cooler  80  adjacent the keg  22  provides for economical spaced placement of the reservoir  92  in the dispensing apparatus  10 . 
     As shown in  FIG. 5 , the reservoir  92  comprises a main body portion  110  having an end wall  112  mounted thereto. The end wall  112  has an exit opening  114  which is connected to tubing  94 . The body portion  110  also has a sealing gasket  116  and a sealing plate  118  adapted to be mounted against the opposite end of the reservoir  92 . This provides an enclosed space  120  which is adapted to be charged with pressurized gas. 
     The pressurized gas is filled into the reservoir  92  by means of compressor  90 . Compressor  90  comprises a motor  122  having a spindle  124  connected to a reciprocating piston  128 . Piston  128  is connected to a cam member  130  by a head bolt  132  passing through a circular opening  134  in the reciprocating piston  128 . The end of piston  128  at  130  is adapted to force air out through opening  140  in the face plate  118  and into the reservoir  92  during an out-take stroke. The opening  118  is sealed by a one way valve  140 . Also provided in the face plate  118  and the sealing member  116  is another opening  150  and  152  respectively. Openings  150  and  152  also are provided with a one way valve  154  and operate to draw air in through the reciprocating piston  128  on an intake stroke. The intake air is provided along the groove  170  provided in the reservoir  92 . 
     During operation, the compressor  90  is activated by energizing motor  90  through a suitable electrical energy supply. The compressor creates a pressure charge within the reservoir  92  which is held in the reservoir  92  by pressure switch  96 . The compressor  90  is controlled to generate this charge in the reservoir  92  until a predetermined charge is sensed in the reservoir  92  or a predetermined time period of compressor operation has expired. At this time, the compressor stops operating. During a dispense cycle, the tap  14  in the apparatus  10  is activated which causes the beer  52 , maintained under pressure in the keg  22 , to move through open end  64  of tube  66  and out through valve  60  to the tap  14  and into the glass container  18 . When the tap  14  is activated, pressure switch  96  opens to allow at least a portion of the charge of pressure to pass from reservoir  92  along tube  94  and in through air valve  98  into the space  62  between the bag  55  and keg walls  22 . This creates additional pressure within head space  62  which is forced against the bag to further deflate the bag and maintain an adequate dispensing flow of the beer through the tap  14  into the glass  18  so as to prevent the beer from frothing and to reduce dampening pressure fluctuations. This is particularly the case when the head space  62  is relatively small and there is need for quick build up of pressure as represented by arrow  63  in order to effect proper dispensing of the beer. 
     During the dispensing operation, the compressor  90  is activated to maintain a consistent pressure to the air reservoir which is passed through the tubing  94  in the event that multiple pours of beverage are being dispensed into glass  18 . After the tap  14  is turned off, the compressor  90  continues to charge the reservoir  92  until either a predetermined pressure is obtained or for a predetermined time period so that a sufficient or adequate pressure charge is once again stored in the reservoir  92 . 
     During a normal dispense cycle wherein beer  52  is dispensed through tube  66  and tap  14  into a glass  18 , the volume of beer dispensed in a normal cycle is that of a full glass of beer. This amount is assumed to be about 8 ounces. During this dispensing of beer  52  out from the bag  55 , the deflation of bag  55  results in a pressure drop in the head space  62 . Initially, when there is little or no head space in the keg  22 , the pressure drop is relatively higher than the pressure drop that occurs when the bag is half full or even a quarter full of beer  52 . 
     In another embodiment, the present invention provides a pair of pressure sensors  100  and  102  which are mounted in the apparatus  10  in pressure sensing relation against the side wall  40  of the keg  22 . The sensors  100  and  102  are responsive to minimum and maximum predetermined values of pressure which are sensed from the side wall  40  which is representative of predetermined minimum and maximum values of pressure within the keg head space  22 . It should be understood that these minimum and maximum pressures are values to which the sensors  100  and  102  are set and may not necessarily represent the minimum and maximum values of pressure change within the head space  62 . The minimum and maximum pressures to which sensors  100  and  102  are set may represent threshold pressures above which the pressure in the keg  22  is to be maintained prior to a dispensing cycle and a lower pressure to which the pressure in keg head space  62  falls during a dispense cycle. 
     A controller  110  measures or monitors the time required for the signals  104  and  106  to be received by the controller  110 . This time difference represents a time rate of pressure change within the head space  62 . This time rate of pressure is output from controller  110  as a volume signal on line  112 . This signal is received by a display  114  which is mounted on the outside or front surface  12  of the dispensing apparatus  20 . As shown in  FIG. 1 , the display  114  has 3 levels of volume indication. The levels are full, medium, or low. Each of these levels represents the amount of beverage  52  contained within the bag  55 . It should be understood that the amount of beverage may be displayed in additional graduated amounts, or alternatively, more than two pressure sensors may be employed. 
     While the preferred embodiment relates to the use of pressure sensors  100  and  102  which generate signals in response to thresholds being exceeded, it should be understood that alternatively, pressure sensor  100  may be a pressure sensor which provides an indication when a maximum value of pressure in the head space  62  has been reached and the pressure sensor  102  may provide an indication when the minimum value of pressure in the head space  62  has been obtained during each dispense cycle. However, by having the pressure sensors set at predetermined thresholds which are less than maximum and minimum pressure thresholds experienced during a normal dispensing cycle, these predetermined thresholds should be exceeded during a normal beer dispensing cycle. 
     In the event that half a glass of beer is dispensed, then the sensor  102  may not exceed its lower threshold to activate signal  106  and, hence, the controller  110  has no means of measuring the time difference between the maximum pressure and the minimum pressure sensed by sensors  100  and  102 . During such an abnormal dispense cycle, the controller  110  is not able to generate a signal which might be faulty with respect to the amount of contents left in the keg  22 . 
     In accordance with one preferred aspect of this embodiment of the present invention, the sensors  100  and  102  provide signals sequentially from the upper value of sensor  100  to the lower value of sensor  102  during a dispense cycle which provides a time rate of pressure drop within the head space  62 . In accordance with another preferred aspect of the present invention, the sensors  100  and  102  send signals to controller  110  which represent the rate of pressure rise within the head space  62  after the dispense operation has finished and during which compressor  90  operates to increase the pressure within the head space  62 . Accordingly, the controller  110  operates to measure the rate of change of pressure either due to a pressure drop during a normal dispense cycle or a pressure increase after a normal dispense cycle has occurred.