Abstract:
A unitary one-piece, disposable package includes a canister for storing a product. A pump housing formed integrally with the canister contains a progressive cavity pump that pumps product from the canister to an outlet chamber of the pump housing and out an outlet from the chamber. A product dispenser for use with the unitary one-piece, disposable package includes a housing, a chamber in the housing for receiving the package, and a motor within the housing for driving the progressive cavity pump of the package. An alternative product dispenser includes a housing having a chamber for receiving a product canister wherein the chamber facilitates communication of product from the canister to a pump chamber. A progressive cavity pump mounts within the pump chamber for pumping product from the canister out an outlet from the pump chamber. A motor within the housing drives the progressive cavity pump.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation-in-part of U.S. patent application Ser. No.  08 / 444 , 169  filed May 18, 1995, which was a continuation-in-part of U.S. patent application Ser. No. 08/178,721 filed Jan. 10, 1994, which was a divisional of U.S. patent application Ser. No. 07/843,757 (now U.S. Pat. No. 5,305,923), which was a continuation of U.S. patent application Ser. No. 07/752,406 filed Aug. 30, 1991 (now abandoned) and having the same title, which was in turn a continuation-in-part of U.S. patent application Ser. No. 07/634,857 filed Dec. 27, 1990 (now abandoned) and having the same title, which was in turn a continuation-in-part of U.S. patent application Ser. No. 07/534,601 filed Jun. 6, 1990 with the same title (now abandoned), and is also a continuation-in-part to U.S. patent application entitled “Progressive Cavity Pump” filed Jun. 14, 1991, Ser. No.  07 / 714 , 433  (now abandoned). 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to dispensing equipment and, more particularly, but not by way of limitation, to a pump and package system utilized in dispensing equipment that dispenses food products, such as ice cream, mustard, ketchup, mayonnaise, soup, salad dressing, and the like.  
           [0004]    2. Description of the Related Art  
           [0005]    The viscosity of food products varies widely and ranges from hard (e.g., ice creams) to semi-liquids (e.g., ketchup and mustard) to liquids (e.g., soups). Hard ice cream typically comes in cartons that are stored in a freezer accessible to ice cream shop employees. An employee manually lifts the ice cream from its carton using a scoop and then places it on a cone or in a dish. The disadvantages of manual dispensing are that the ice cream remains uncovered for long periods and employees often contact the ice cream which is unsanitary.  
           [0006]    Ketchup and mustard usually have separate dispensers that consist of a container having a pump. Although employees do not directly dispense ketchup and mustard, an employee must fill the dispensers when they are empty. That results in direct employee contact with both the dispensers and the ketchup and mustard. Furthermore, if the dispensers are not routinely cleaned or are cleaned improperly, an unsanitary condition situation arises.  
           [0007]    Employees normally prepare soups on site by mixing a soup concentrate with water. An employee places the soup in a heated cauldron and then ladles the soup into containers for customer consumption. Thus, soups also contact employees and are open to the environment thereby allowing the spread of bacteria and germs.  
           [0008]    Accordingly, an apparatus that permits the self-contained dispensing of food products, such as ice cream, mustard, ketchup, mayonnaise, soup, salad dressing, and the like, will improve sanitary conditions in the food service industry.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with the present invention, a unitary onepiece, disposable package includes a canister for storing a product. The canister includes a fill opening, a fill cap for the fill opening, and a piston for forcing product from the canister. A pump housing formed integrally with the canister contains a progressive cavity pump that pumps product from the canister to an outlet chamber of the pump housing and out an outlet from the chamber.  
           [0010]    The pump housing includes an intermediate wall defining a stator chamber. The stator chamber contains a stator of the progressive cavity pump that communicates with the outlet chamber of the pump housing. The progressive cavity pump includes a rotor within said stator having a shaft connectable to a motor drive shaft. The rotor includes a conduit therethrough that communicates with the outlet chamber of said pump housing. The rotor further includes vanes at the opposite end of the rotor shaft that extend into the outlet chamber of the pump housing.  
           [0011]    A product dispenser for use with the unitary one-piece, disposable package includes a housing, a chamber in the housing for receiving the package, and a motor within the housing for driving the progressive cavity pump of the package. The product dispenser includes within the housing either a refrigeration unit for refrigerating the chamber or a heating element for heating the chamber. The product dispenser further includes a system mounted within the housing for forcing product from the canister into the pump housing.  
           [0012]    An alternative product dispenser includes a housing having a chamber for receiving a product canister wherein the chamber facilitates communication of product from the canister to a pump chamber. A progressive cavity pump mounts within the pump chamber for pumping product from the canister out an outlet from the pump chamber. A motor within the housing drives the progressive cavity pump. The alternative product dispenser includes within the housing either a refrigeration unit for refrigerating the chamber or a heating element for heating the chamber. The product dispenser further includes a system mounted within the housing for forcing product from the canister into the progressive cavity pump.  
           [0013]    It is, therefore, an object of the present invention to provide a unitary one-piece, disposable package with a progressive cavity pump capable of pumping viscous products.  
           [0014]    It is another object of the present invention that the package including the progressive cavity pump be inexpensive and disposable.  
           [0015]    It is a further object of the present invention to provide a dispenser with a progressive cavity pump that pumps product from a disposable canister placed in the dispenser.  
           [0016]    Still other objects, features, and advantages of the present invention will become evident to one of ordinary skill in the art in light of the following.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view in partial cross-section illustrating a first embodiment of a canister including a progressive cavity pump formed integrally therewith.  
         [0018]    [0018]FIG. 2 is a partial right side elevation view in cross-section illustrating a first embodiment of a canister including a progressive cavity pump formed integrally therewith.  
         [0019]    [0019]FIG. 3 is a front elevation view along lines  3 - 3  of FIG. 2 illustrating the vanes mounted at the front of the progressive cavity pump rotor.  
         [0020]    [0020]FIG. 4 is a partial right side elevation view in cross-section illustrating a second embodiment of a canister including a progressive cavity pump formed integrally therewith that permits mixing of a mixing fluid with product in the canister.  
         [0021]    [0021]FIG. 5 is a right side elevation view in cross-section illustrating a dispenser for dispensing a frozen product.  
         [0022]    [0022]FIG. 6 is a right side elevation view in cross-section illustrating a dispenser for dispensing a product at room temperature.  
         [0023]    [0023]FIG. 7 is a right side elevation view in cross-section illustrating a dispenser for dispensing a heated product.  
         [0024]    [0024]FIG. 8 is a right side elevation view in cross-section illustrating an alternative dispenser that includes a progressive cavity pump mounted therein.  
         [0025]    [0025]FIG. 9 is a perspective view in partial cross-section illustrating a canister for use with the alternative dispenser.  
         [0026]    [0026]FIG. 10 is a partial right side elevation view in cross-section illustrating the mounting of a canister and a progressive cavity pump within the alternative dispenser.  
         [0027]    FIGS.  11 A-C are partial right side elevation views in cross-section illustrating a first embodiment of an air drive assembly in an unpressurized, partially pressurized, and fully pressurized operating position.  
         [0028]    FIGS.  12 A-C are partial right side elevation views in cross-section illustrating a second embodiment of the air drive assembly in an unpressurized, partially pressurized, and fully pressurized operating position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]    FIGS.  1 - 3  illustrate a first embodiment of a one-piece unitary package  10 . One-piece unitary package  10  includes a canister  11  and a progressive cavity pump  12 . The canister  11  has a cylindrical side wall  13 , a top wall  14 , a bottom wall  15 , a product chamber  16 , and a product outlet  17 . The canister  11  preferably includes an opening  18  in the top wall  14  thereof covered by a label  19  that may be pierced to permit the introduction of a pressurized fluid into the canister  11 . The opening  18  is not essential because the fluid could alternatively be introduced through the top wall  14  after it has been punctured. The canister  11  includes a piston  20  that is forced down by the fluid pressure to push the product into the pump  12 . Although canister  11  has been described with the piston  20  operated by fluid pressure, the piston  20  is not essential because the fluid pressure could be applied directly to the product. Furthermore, certain less viscous products, such as ketchup, mustard, and soup concentrate, will enter the pump  12  under the force of gravity, thus eliminating the necessity for the introduction of fluid pressure into canister  11 .  
         [0030]    In the preferred embodiments, the canister  11  is injection molded of polyethylene with a wall thickness of about 0.060 inch. The canister  11  is then hot plate welded to the pump  12 , which is also injection molded of polyethylene. The package  10  is designed for upside-down orientation during shipping. The canister  11  is filled through an opening  30  adjacent the pump  12 . A cap  40  seals the opening  30  after filling.  
         [0031]    While other types of pumps could be used in package  10 , the pump  12  in the preferred embodiments is a progressive cavity pump. The pump  12  includes a housing  21  having an intermediate wall  22  to define a stator chamber  23 . A stator  24  abuts the wall  22 . The wall  22  has an opening  25  that is a bearing for a ring  26  of a rotor  27 . The ring  26  has openings or serrations  28  in its periphery that provide product inlet openings into the pump  12 . The rotor  27  includes a shaft  34  that connects to any suitable dispenser drive unit, such as a motor, to facilitate the rotation of rotor  27 . The rotor shaft  34  includes a labyrinth seal  29  where it rotatably extends through the housing  21 . The rotor  27  further includes vanes  33  that break pumped product into segments to reduce the back pressure on the stator  24 . The stator  24  moves or flexes sideways during pumping by virtue of the flexible seal  31  to avoid the necessity of an expensive constant velocity joint in the pump  12 .  
         [0032]    In operation, the piston  20  forces product into the pump  12  through the product outlet  17 . The product enters the stator  24  through the openings or serrations  28  of the ring  26  where the rotor  27  pumps the product to a chamber  32 . As the rotor  27  rotates, progressive cavities formed between the stator  24  and the rotor  27  move the product to the chamber  32 . The vanes  33  of the rotor  27  extend into the chamber  32  to break the pumped product into segments thereby reducing the back pressure on the stator  24 . The product exits the chamber  32  and passes into outlet  38  for dispensing into an appropriate container.  
         [0033]    [0033]FIG. 4 illustrates a second embodiment of the unitary one-piece package  10  with like parts being referenced with like numerals. The pump  12  includes a housing  21  having an intermediate wall  22  to define a stator chamber  23 . A stator  24  abuts the wall  22 . The stator  24  moves or flexes sideways during pumping by virtue of a flexible seal  31  to avoid the necessity of an expensive constant velocity joint in the pump  12 . The wall  22  has an opening  25  that is a bearing for a ring  26  of a rotor  27 . The ring  26  has openings or serrations  28  in its periphery that provide product inlet openings into the pump  12 . The rotor  27  includes a shaft  34  that connects to any suitable dispenser drive unit, such as a motor, to facilitate the rotation of rotor  27 . The rotor shaft  34  includes a labyrinth seal  29  where it rotatably extends through the housing  21 . The rotor  27  further includes vanes  33  that break pumped product into segments to reduce the back pressure on the stator  24 . A conduit  35  extends completely through the rotor  27  including the rotor shaft  34  and the vanes  33  to deliver a mixing fluid into a chamber  32  via an opening  39 . A fluid line  36  connects to a mixing fluid source and to a fluid block  37  communicating with the conduit  35  to deliver mixing fluid into the conduit  35 .  
         [0034]    In operation, the piston  20  forces product into the pump  12  through the product outlet  17 . The product enters the stator  24  through opening  25  where the rotor  27  pumps the product to the chamber  32 . As the rotor  27  rotates, progressive cavities formed between the stator  24  and the rotor  27  move the product to the chamber  32 . The vanes  33  of the rotor  27  extend into the chamber  32  to break the pumped product into segments thereby reducing the back pressure on the stator  24  which permits improved mixing with the mixing fluid. The fluid line  36  delivers mixing fluid into the conduit  35  via the fluid block  37 . The mixing fluid exits the conduit  35  into the chamber  32  through the opening  39 . The wall of the chamber  32  opposing the opening  39  deflects the mixing fluid rearwardly into the chamber  32  where it dislodges product from the vanes  33 . The mixing fluid and product mix and then exit the chamber  32  through the outlet  38  into an appropriate container. The outlet  38  may contain a static mixer to furnish additional mixing prior to dispensing.  
         [0035]    [0035]FIG. 5 illustrates a dispenser  50  for dispensing a product requiring refrigeration such as ice cream. The dispenser  50  includes a housing  51  that contains a compartment  52 , a cooling chamber  53  for holding a cooling fluid, and a canister chamber  54 . The housing  51  contains a conventional refrigeration unit that consists of a compressor  55 , a blower  56 , and a condenser coil  57  in the compartment  52  and an evaporator coil  58  in the cooling chamber  53 . The refrigeration unit operates to cool the cooling fluid within the cooling chamber  53  until the formation of a cooling fluid bank around the evaporator coil  58 . The cooling chamber  53  abuts the canister chamber  54  to furnish heat exchange therebetween thereby refrigerating the canister chamber  53 .  
         [0036]    The dispenser  50  includes a motor  59  for driving the pump  12  of the package  10 . The motor  59  connects to any suitable power source, such as a standard AC line, and is controlled by a switch mounted on the housing. A fluid pressure drive assembly  60  injects a pressurized fluid into the canister  11  to facilitate the driving of the piston  20 . A line  61  connects to the fluid pressure drive assembly  60  and to a pressurized fluid source to deliver pressurized fluid to the fluid pressure drive assembly  60 . A system user accesses the canister chamber  54  through a door  59  mounted on housing  51 .  
         [0037]    To load the dispenser  50 , the door  59  is opened and the canister  11  inserted into the canister chamber  54  until the male socket member of the pump rotor shaft  34  engages a female socket in the drive shaft of the motor  59 . The fluid pressure drive assembly  60  attaches over the canister  11  to pressurize the portion of the canister  11  above the piston  20 . The closure of the door  59  activates the dispenser  50  which is then ready to dispense the frozen product contained in the canister  11 . Upon the actuation of the motor switch, the motor  59  receives power to drive the rotor  27  thereby facilitating the dispensing of the product from the pump  12  as previously described with respect to FIGS. 1 and 2.  
         [0038]    [0038]FIG. 6 illustrates a dispenser  70  for dispensing a product requiring no refrigeration such as ketchup, mustard, or mayonnaise. The dispenser  70  includes a housing  71  that contains a canister chamber  72  and a motor  73  for driving the pump  12  of the package  10 . The motor  73  connects to any suitable power source, such as a standard AC line, and is controlled by a switch mounted on the housing. A fluid pressure drive assembly  74  injects a pressurized fluid into the canister  11  to facilitate the driving of the piston  20 . A line  75  connects to the fluid pressure drive assembly  74  and to a pressurized fluid source to deliver pressurized fluid to the fluid pressure drive assembly  74 . A system user accesses the canister chamber  72  through a door  76  mounted on housing  71 .  
         [0039]    To load the dispenser  70 , the door  76  is opened and the canister  11  inserted into the canister chamber  72  until the male socket member of the pump rotor shaft  34  engages a female socket in the drive shaft of the motor  73 . The fluid pressure drive assembly  74  attaches over the canister  11  to pressurize the portion of the canister  11  above the piston  20 . The closure of the door  76  activates the dispenser  70  which is then ready to dispense the product contained in the canister  11 . Upon the actuation of the motor switch, the motor  73  receives power to drive the rotor  27  thereby facilitating the dispensing of the product from the pump  12  as previously described with respect to FIGS. 1 and 2.  
         [0040]    [0040]FIG. 7 illustrates a dispenser  80  for dispensing a product, such as a soup, that requires heat and further the introduction of a mixing fluid. Although the dispenser  80  will be described with both heat and water sources, one of ordinary skill in the art will recognize that the combination of both sources is not always required. The dispenser  80  includes a housing  81  that contains a canister chamber  82 . The walls of the canister chamber  82  enclose a heating element  83  utilized to warm the product contained in the canister  11 . In this preferred embodiment, the heating element  83  may be any suitable resistive heating element that receives power from a standard AC voltage line.  
         [0041]    The dispenser  80  includes a motor  84  for driving the pump  12  of the package  10  and a fluid line  85  for delivering mixing fluid into the conduit  35  within the rotor  27 . The fluid line  85  connects to the fluid block  37  of the pump  12  using any suitable means such as a threaded fitting and to any suitable mixing fluid source, such as a standard water line. The fluid line  85  includes a valve that controls the flow of mixing fluid to the fluid block  37 . The motor  84  and the valve of the fluid line  85  connect to any suitable power source, such as a standard AC line, and are controlled by a switch mounted on the housing.  
         [0042]    The dispenser  80  includes a fluid pressure drive assembly  86  that injects a pressurized fluid into the canister  11  to facilitate the driving of the piston  20 . A line  87  connects to the fluid pressure drive assembly  86  and to a pressurized fluid source to deliver pressurized fluid to the fluid pressure drive assembly  86 . A system user accesses the canister chamber  82  through a door  88  mounted on housing  81 .  
         [0043]    To load the dispenser  80 , the door  88  is opened and the canister  11  inserted into the canister chamber  82  until the male socket member of the pump rotor shaft  34  engages a female socket in the drive shaft of the motor  84 . The fluid pressure drive assembly  86  attaches over the canister  11  to pressurize the portion of the canister  11  above the piston  20 . The mixing fluid line  85  is connected to a mixing fluid source and to the fluid block  37  on the pump  12  to deliver mixing fluid into the conduit  35  within the rotor  27 . The closure of the door  88  activates the dispenser  80  which is then ready to dispense the product contained in the canister  11 . Upon the actuation of the motor and valve switch, the motor  73  receives power to drive the rotor  27  and the fluid line  85  delivers mixing fluid thereby facilitating the dispensing of the mixed product from the pump  12  as previously described with respect to FIG. 4.  
         [0044]    [0044]FIG. 8 illustrates an alternative dispenser  170  that includes a progressive cavity pump  180  mounted therein. The dispenser  170  dispenses a product requiring no refrigeration or heating such as ketchup, mustard, or mayonnaise, however, one of ordinary skill in the art will recognize that the dispenser  170  could easily be modified to include the refrigeration unit or heating element described with reference to FIGS. 5 and 7, respectively. The dispenser  170  includes a housing  171  that contains a canister chamber  172  and a pump chamber  182 . A conduit  200  attaches to the bottom wall of the canister chamber  172  to provide a support for a canister and the progressive cavity pump  180  and, further, to provide a passage for fluid communication therebetween. A motor  173  attached to the pump chamber  182  drives the pump  180  which resides within the pump chamber  182 . The motor  173  connects to any suitable power source, such as a standard AC line, and is controlled by a switch mounted on the housing. A fluid pressure drive assembly  174  injects a pressurized fluid into the canister  181  to facilitate the driving of the piston  182 . A line  175  connects to the fluid pressure drive assembly  174  and to a pressurized fluid source to deliver pressurized fluid to the fluid pressure drive assembly  174 . A system user accesses the canister chamber  172  through a door  176  mounted on housing  171 .  
         [0045]    [0045]FIG. 9 illustrates a canister  181  utilized with the alternative dispenser. The canister  11  has a cylindrical side wall  183 , a top wall  184 , a bottom wall  185 , a product chamber  186 , and a product outlet  187 . The canister  181  preferably includes an opening  188  in the top wall  184  thereof covered by a label  189  that may be pierced to permit the introduction of a pressurized fluid into the canister  181 . The opening  188  is not essential because the fluid could alternatively be introduced through the top wall  184  after it has been punctured. The canister  181  includes a piston  190  that is forced down by the fluid pressure to push the product into the pump  180 . Although canister  181  has been described with the piston  190  operated by fluid pressure, the piston  20  is not essential because the fluid pressure could be applied directly to the product. Furthermore, certain less viscous products, such as ketchup, mustard, and soup concentrate, will enter the pump  180  under the force of gravity, thus eliminating the necessity for the introduction of fluid pressure into canister  181 .  
         [0046]    In the preferred embodiments, the canister  181  is injection molded of polyethylene with a wall thickness of about 0.060 inch. The canister  181  is designed for upside-down orientation during shipping. The canister  181  is filled through the outlet  187 . A seal  191  that is preferably a foil covers the outlet  187  and attaches thereto using any suitable means such as an adhesive. A cap  192  attaches to the outlet  187  to cover the seal  191  after the filling of the canister  181 .  
         [0047]    [0047]FIG. 10 illustrates the progressive cavity pump  180  and the canister  181  that both mount to the conduit  200  of the dispenser  170 . Although the pump  180  is a progressive cavity pump, one of ordinary skill in the art will recognize that other types of pumps may be used. Furthermore, although the pump  180  is not illustrated with a mixing fluid conduit, one of ordinary skill in the art will recognize that one similar to that described in reference to FIG. 4 could be provided.  
         [0048]    The pump  180  includes a housing  192  having an intermediate wall  193  to define a stator chamber  194 . Housing  192  includes inlet  195  that attaches to conduit  200  to suspend the progressive cavity pump  180  within the pump chamber  182 . The inlet  195  of the housing  192  attaches to conduit  200  using any suitable means such as protrusions  196  and  197  that fit within a groove  198  or, alternatively, through a threaded connection.  
         [0049]    A stator  199  abuts the wall  193  which includes an opening  201  that is a bearing for a ring  202  of a rotor  203 . The ring  202  has openings or serrations  204  in its periphery that provide product inlet openings into the pump  180 . The rotor  203  includes a shaft  205  having a male socket member that engages a female socket in the drive shaft of the motor  173 . The rotor shaft  205  includes a labyrinth seal  206  where it rotatably extends through the housing  192 . The rotor  203  further includes vanes  207  that break pumped product into segments to reduce the back pressure on the stator  199 . The stator  199  moves or flexes sideways during pumping by virtue of the flexible seal  208  to avoid the necessity of an expensive constant velocity joint in the pump  180 .  
         [0050]    The conduit  200  includes threads  209  that engage the threads on outlet  187  to permit the securing of the canister  181  to the conduit  200  and thus within the canister chamber  172 . For products sufficiently viscous that the upending of the canister  181  will not result in the spilling of product, the seal  191  is removed prior to the attachment of the canister  181  to the conduit  200 . However, conduit  200  includes a piercing tool  210  mounted at its inlet. The piercing tool  210  includes crossed knife edges that pierce the seal  191  during the securing of the canister  181  to the conduit  200 . After puncturing of the seal  191  by the piercing tool  210 , the product forces the seal  191  pieces against the inner wall of the conduit  200  to prevent them from interfering with product flow.  
         [0051]    To load the dispenser  170 , the door  176  is opened and the canister  181  inserted into the canister chamber  172  as previously described to begin the delivery of product from the canister  181  to the progressive cavity pump  180  via conduit  200 . The fluid pressure drive assembly  174  attaches over the canister  181  to pressurize the portion of the canister  181  above the piston  190 . The piston  190  forces product into the pump  180  through the outlet  187  and conduit  200 . The closure of the door  176  activates the dispenser  170  which is then ready to dispense the product contained in the canister  181 . Upon&#39;the actuation of the motor switch, the motor  173  receives power to drive the rotor  203  thereby facilitating the dispensing of the product from the pump  180 .  
         [0052]    Specifically, the product enters the stator  199  through the openings or serrations  204  of the ring  202  where the rotor  203  pumps the product to a chamber  211  mounted to the pump housing  192 . As the rotor  203  rotates, progressive cavities formed between the stator  199  and the rotor  203  move the product to the chamber  211 . The vanes  207  of the rotor  203  extend into the chamber  211  to break the pumped product into segments thereby reducing the back pressure on the stator  199 . The product exits the chamber  211  and passes into outlet  212  for dispensing into an appropriate container.  
         [0053]    FIGS.  11 A-C illustrate a first embodiment of the fluid pressure drive assembly  60  in an unpressurized, partially pressurized, and fully pressurized operating position. The fluid pressure drive assemblies  74  and  86  are identical to the fluid pressure drive assembly  60  and will therefore not be described.  
         [0054]    The fluid pressure drive assembly  60  pressurizes the inside of the canister  11  to drive the piston  20  thereby forcing product into the pump  12 . The fluid pressure drive assembly  60  receives compressed fluid from any suitable compressed fluid source, such as a compressed air tank, through the line  61 . After the insertion of the canister  11  into the canister chamber  54 , compressed fluid is delivered to the top of a spring assembly  90  which is movably connected to a spring  91 . As the pressure increases, the spring assembly  90  compresses the spring  91  until its inner edge  101  resides in a cavity  92  and its lower plate portion  102  rests upon the top of the canister  11  (see FIG. 11B). In that position, the inner edge  101  exposes a conduit  99  communicating with a cavity  93 .  
         [0055]    Compressed fluid enters the cavity  93  via the conduit  99  to begin the compression of a spring  95  by a plate  94  of the spring assembly  90 . As the pressure above the plate  94  increases, it moves downward to force any fluid contained in a cavity  97  through outlet  98 , thereby reducing the resistive pressure to the downward movement of the plate  94 . The fluid pressure above the plate  94  continues to increase until it overcomes the resistive force of the spring  95  and moves downward with a force sufficient for a hollow punch  96  to puncture the canister  11  (see FIG. 11C).  
         [0056]    That puncturing allows compressed fluid to enter the canister  11  and pressurize the portion of canister  11  above the piston  20 . During regular dispensing operations, the fluid pressure on the plate  94  remains at a level sufficient to maintain the springs  91  and  95  completely compressed. Furthermore, the pressure maintained above the piston  20  is sufficient for the piston  20  to force product into the pump  12 .  
         [0057]    FIGS.  12 A-C illustrate a second embodiment of the fluid pressure drive assembly  60  in an unpressurized, partially pressurized, and fully pressurized operating position. The fluid pressure drive assemblies  74  and  86  are identical to the fluid pressure drive assembly  60  and will therefore not be described.  
         [0058]    The fluid pressure drive assembly  60  pressurizes the inside of the canister  11  to drive the piston  20  thereby forcing product into the pump  12 . The fluid pressure drive assembly  60  receives compressed fluid from any suitable compressed fluid source such as a compressed air tank, through the line  61 . After the insertion of the canister  11  into the canister chamber  54 , compressed fluid is delivered to the top of a spring assembly  110  which is movably connected to a spring  111 . Initially, the pressure above the spring assembly  110  increases to overcome the resistive force of the spring  111  which lowers the spring assembly  110  until a punch assembly  112  punctures the canister  11  (see FIG. 12B).  
         [0059]    The punch assembly  112  includes a hollow punch  113 , a spring  114 , a spring  115 , and a guard  116  that are all attached to a plate portion  119  of the spring assembly  110 . The guard  116  is a circular shroud about the hollow punch  113  that is attached to the lower plate portion of the spring assembly  110  by the spring  114  and used to prevent injuries due to the sharp point of the hollow punch  113 . The spring  115  allows the spring assembly  110  to move relative to the guard  116 , thus, allowing the hollow punch  113  to penetrate the canister  11 . The spring  115  attaches to a flange  117  of the hollow punch  113  and also to the lower plate portion  119  of the spring assembly  110 .  
         [0060]    As the pressure in cavity  118  increases, the restoring force of the spring  115  is initially sufficient to maintain the head of the hollow punch  113  resting on top of the plate portion  119  of the spring assembly  60 . In that position, the hollow punch  64  remains sufficiently rigid to puncture the canister  11 . However, after the canister  11  has been punctured, the pressure in the cavity  118  increases until the spring  111  fully compresses and the restoring force of the spring  115  is overcome, thereby creating a cavity  120  (see FIG. 12C). As the spring assembly  110  moves away from the hollow punch  113 , an orifice  121  in the shaft portion of the hollow punch  113  is exposed. The orifice  121  delivers compressed fluid from the cavity  118  to the canister  11  through the hollow shaft portion of the hollow punch  64 . During regular dispensing operations, the fluid pressure in the cavity  118  and also the canister  11  remains at a level sufficient for the piston  20  to force product into the pump  12 .  
         [0061]    Although the preferred embodiments disclose the use of fluid pressure to operate the piston  20  of the canister  11 , one of ordinary skill in the art will readily recognize that a mechanical means such as a push rod could be substituted.  
         [0062]    From the foregoing description and illustration of this invention, it is apparent that various modifications can be made by reconfigurations or combinations to produce similar results. It is, therefore, the desire of the Applicant not be bound by the description of this invention as contained in this specification, but to be bound only by the claims as appended hereto.