Abstract:
Provided is a brewing device which is portable and does not require the use of electricity, as well as a method of brewing using the portable brewing device. The device includes an outer cylinder and an inner cylinder that function together like a piston in a cylinder. The inner cylinder includes a filter for holding brewing solids at one end. The inner cylinder is dimensioned to slide within the outer cylinder and create a water tight frictional fit with the outer cylinder. Thus, when the inner cylinder is pushed into the outer cylinder filled with liquid, the liquid is force to pass through the filter and into the inner cylinder as brewed liquid.

Description:
This application claims the benefit of provisional application Nos. 61/114,319 filed Nov. 13, 2008 and 61/204,151 filed Jan. 3, 2009. The entire content of each prior application is expressly incorporated by reference herein by reference thereto. 
    
    
     TECHNICAL FIELD 
     The present invention relates to brewing devices. More particularly, the present invention relates to a portable beverage brewing system for various beverages including coffee or tea. 
     BACKGROUND 
     Attempts have been made to provide portable coffee brewing devices that may be operated without a power source. These portable devices may be referred to as French presses. The French press comprises a container and a filter plate joined to a shaft. Coffee grounds and water are inserted into the container and mixed together. The filter plate is then inserted into the container and the shaft connected to the filter plate is pushed down so that the filter plate travels down in the container. The filter is arranged so that as it travels down in the container, liquid coffee passes up through the filter plate while the grounds are trapped on or adjacent to the bottom face of the filter plate. Eventually, the liquid coffee in the container is separated from the solid grounds by the filter plate. The container may then be opened and the liquid coffee poured out or consumed directly. 
     There are several undesirable limitations associated with the use of a French press for making brewed coffee. First, it is difficult to effectively separate the grounds from the liquid coffee. The filter pores must be big enough to allow the liquid coffee to pass therethrough using a reasonable amount of manual pressure to isolate the grounds from the liquid. As a result, small coffee particles also pass through the filter pores and the brewed coffee contains an undesirable quantity of coffee grounds. Second, the brewing process can be lengthy because it takes considerable time to adequately mix the coffee grounds with the water and press the brewed coffee. Thus, the hot water used to make the brewed coffee may cool in the time it takes to brew the coffee. 
     There is a need for a portable brewing device that effectively separates the solids from the brewed liquid, brews the liquid in a short period of time, and is relatively easy to use, self contained and easy to transport. 
     SUMMARY OF THE INVENTION 
     The present invention now provides a portable brewing device that effectively separates solid particles from a brewed liquid. It also provides a portable brewing device that accomplishes the brewing in a relatively short period of time. Further, the portable brewing device is relatively easy and safe to use, self contained and easy to transport. The present invention is described with reference to brewing coffee but is not limited thereto as it may be used to make any type of beverage involving the combination of a liquid and a granular solid. 
     In particular, the present invention is a portable piston driven brewing device. The device requires no power supply and includes a pair of interoperable cylinders that function like a piston. The cylinders have a hollow tubular construction. The outer cylinder is closed at one end and open at the other end to receive the inner cylinder. The inner cylinder comprises ports on opposing ends. The inner cylinder is configured with outer dimensions to establish a watertight, frictional fit with the interior dimensions of the outer cylinder. The outer surface of the inner cylinder may include a sealing structure, such as an o-ring structure, to ensure the watertight fit between the two cylinders. 
     The device of the present invention also includes a filter structure. The filter structure comprises a plurality of pores in a mesh-like formation. The filter structure is preferably removably retained within the inner cylinder. The filter structure is used to hold solid particles therein, such as coffee grounds, for example. The filter structure is positioned in the inner cylinder adjacent to the port hole on one end. 
     In order to use the device, hot water or another liquid of choice, whether hot or cold, is placed in the outer cylinder. The solids of choice are placed in the filter structure and the filter structure is positioned in one end of the inner cylinder and retained in its position by a cap. The end of the inner cylinder having the filter structure is then forced into the outer cylinder through the outer cylinder&#39;s opening. This action causes the liquid in the outer cylinder to pass into through filter structure and into the inner cylinder. The pushing of the inner cylinder into the outer cylinder forces the liquid to pass over the solids contained in the filter and out through the pores of the filter into an interior region of the inner cylinder. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is an exploded view of the first embodiment portable brewing device of the present invention; 
         FIG. 2A  is a side view of the inner tube of the first embodiment of the portable brewing device with the filter structure in phantom retained therein 
         FIG. 2B  is a side view of the first embodiment of the portable brewing device with the inner tube partially inserted into the outer cylindrical tube and the filter structure shown in phantom. 
         FIG. 3  is a side view of the first embodiment of the portable brewing device with the inner tube and the filter structure shown in phantom within the outer tube. 
         FIG. 4  is a side view of the first embodiment of the outer tube and its removable closure cap. 
         FIG. 5  is a side view of the outer tube of a second embodiment of the portable brewing device having a removable base with a conduit for attachment to a liquid supply. 
         FIG. 6  is a side view of the second embodiment of the portable brewing device with the inner cylinder partially inserted into the outer cylinder and the filter structure shown in phantom. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment of a portable coffee brewing device  100  of the present invention is illustrated in  FIGS. 1-3 . The device  100  includes an outer tube  10 , an inner tube  11 , a first cap  12 A, a second cap  12 B, and a filter  14 . The device  100  may optionally include a handle disposed on the outer cylinder for easy transport. 
     In the embodiments disclosed herein, outer tube  10  and inner tube are cylindrical and have circular transverse cross sections. The present invention, however, is not limited to cylindrical tubes  10 ,  11 . For example, outer tube  10  and inner tube  11  may have corresponding square, rectangular, or triangular transverse cross sections. 
     The outer tube  10  and the inner tube  11  are preferably fabricated of a non-porous material. For example, either or both of the outer tube  10  and the inner tube  11  may be fabricated of stainless steel or aluminum, but they are not limited thereto. More generally, they are preferably fabricated of one or more materials capable of insulating a liquid contained therein. 
     The outer tube  10  and the inner tube  11  are configured such that the inner tube  11  can slide longitudinally within outer tube  10 . Further, the internal dimensions of outer tube  10  and the outer dimensions of inner tube  11  are adapted to provide a close frictional fit between outer tube  10  and inner tube  11  when fitted together. Additionally, one or more sealing means  13 , such as o-rings  13 , may be disposed on an exterior surface of the inner tube  11  or the interior surface of the outer tube  10  to enable a watertight seal between the inner tube  11  and the outer tube  10 . Preferably, the o-rings  13  are disposed at or near a first end  11 A of inner tube  11 . 
     Outer tube  10  of device  100  includes closed end  10 A, open end  10 B, and wall  10 C defining an interior space. In the embodiments shown herein, wall  10 C forms cylindrical tube having a circular transverse cross section. The present invention, however, is not so limited and may comprise an outer tube  10  having a square, rectangular, or triangular transverse cross section. Open end  10 B includes opening  40  having dimensions suitable to receive inner tube  11  therein. Outer tube  10  defines an interior space that is preferably dimensioned to retain the entire inner tube  11  therein. The outer tube  10  may be fabricated such that wall  10 C and closed end  10 A thereof are integrally formed as a unitary structure. Alternatively, wall  10 C and closed end  10 A may be fabricated separately and joined together, such as, for example, by welding or bonding. 
     Also, as illustrated in  FIG. 4 , closed end  10 A may be a removable cap  18  attached to the end of cylinder  10  by any suitable means, such as, for example, mating threads disposed on a surface of the removable cap and a surface on the end of cylinder  10 . Closure cap  18  may optionally include sealing means  19 , such as a sealing o-ring  19 , arranged to minimize leakage of liquid from outer tube  10  and inner tube  11 . Closure cap  18  includes a surface that contacts first cap  12 A when first cap  12 A is attached to first end  11 A of inner tube  11 . Closed end  10 A or removable cap may optionally comprise a suction pad  27  attached thereto to provide stability to device  100  when placed on a support surface. 
     Inner tube  11  includes a first end  11 A, a second end  11 B, and a wall  11 C. Wall  11 C forms a tube defining an interior space and open first and second ends  11 A,  11 B. In the embodiments shown herein, wall  11 C forms cylindrical tube having a circular transverse cross section, corresponding to the cylindrical tube structure of outer tube  10 . The present invention, however, is not so limited and may comprise an inner tube  11  having a square, rectangular, or triangular transverse cross section corresponding to the configuration of outer tube  10 . 
     First end  11 A and the second end  11 B of inner tube  11  include means for removably attaching thereto first cap  12 A and second cap  12 B, respectively. For example, as illustrated in  FIG. 1 , first end  11 A and second end  11 B are threaded for threading engagement with threading on interior side walls of first cap  12 A and second cap  12 B. First cap  12 A includes a first port  41 A and second cap  12 B includes a second port  41 B. Second port  41 B may include a one-way valve  15 , such as the one-way valves used in water bottles, for example, but is not limited thereto. The valve facilitates drinking brewed liquid directly from inner tube  11  without having to remove end cap  12 B. 
     Any one or more of the caps and lids described herein may be alternatively attached by a quick release structure not requiring rotation to be attached or removed from outer tube  10  and inner tube  11 . Also, any one or more of the caps or lids described herein may be textured, such as by knurling, for example, for ease of manipulation. Further, any one or more of the caps or lids described herein may be fabricated with insulative characteristics and generally fabricated to stand up to the environment and usage to be expected. 
     In the embodiment shown herein, filter  14  is a mesh structure configured to fit within the interior of the inner tube  11 . As shown in  FIG. 1 , filter  14  may be a mesh basket having a truncated cone structure; however, the configuration of filter  14  is not limited thereto. Filter  14  includes a flange  14 A disposed around the periphery of filter  14 . Flange  14 A is preferably dimensioned larger than the interior dimension of inner tube  11  and smaller than the interior dimension of cap  12 A, such that filter  14  may be retained in inner tube  11  and cap  12 A may be attached to first end  11 A of inner tube  11 . Filter  14  comprises pores sized small enough to retain therein pieces of solids including, for example, coffee grounds, but not limited thereto. The pores are also sized sufficiently large enough to allow a liquid, such as water, but not limited thereto, to pass through. 
     Although filter  14  has been shown and described as a separate component, in another embodiment, filter  14  may be permanently affixed to inner tube  11 . Filter  14  may be permanently affixed to inner tube  11  by bonding, welding, integrally fabricating it with the inner tube  11 , or other means of permanent attachment of the filter  14  to inner tube  11  within the interior of the first end  11 A. In this optional arrangement, the used contents of filter  14  may be removed from either end of inner tube  11 , such as by forcing cleaning water or solution through first end  11 A or second end  11 B of inner tube  11 . 
     As shown in  FIG. 2A , filter  14  may be filled with coffee grounds and inserted into first end  11 A of inner tube  11 . Once the filled filter  14  has been inserted into inner tube  11 , cap  12 A may be attached to first end  11 A of inner tube  11 . Also, second cap  12 B may be attached to second end  11 B of inner tube  11 . Then, outer tube  10  may be filler with a liquid for brewing. For example, the liquid may be hot water at a temperature sufficient to enable coffee brewing. Outer tube  10  may optionally include a fill line to enable the user to gauge a suitable amount of liquid to add to outer tube  10 . Device  100  may be used without a fill line as guidance; however, the user may be subjected to an unexpected stream of hot liquid exiting second port  41 B if outer tube  10  is overfilled, or the user may end with a beverage of high flavor concentration if outer tube  10  is underfilled. 
     As shown in  FIG. 2B , the combination of inner tube  11 , filter  14 , and end caps  12 A,  12 B may then be inserted into the opening  40  of outer tube  10 . As the inner tube  11  is slid down into the interior space of outer tube  10 , the liquid is forced to pass through first port  41 A, through filter  14 , and into the interior space of inner tube  11  due to the frictional fit between inner tube  11  and the outer tube  10  and/or sealing means  13 . The liquid contacts the solids (e.g. coffee grounds) within filter  14  to produce a brewed liquid. 
     With reference to  FIG. 3 , when inner tube  11  is completely pushed down into the interior space of outer tube  10 , first cap  12 A is at or near the bottom of closed end  10 A of outer tube  10 . The substantial pressure produced by the piston action generated by forcing inner tube  11  into outer tube  10  causes the liquid to contact substantially all of the surfaces of the solids in the filter  14  and pass through the pores of the filter  14  in substantially all directions before reaching the interior space of inner tube  11  as brewed liquid. The brewed liquid may then be poured from the interior region of the inner tube  11  via second port  41 B of second cap  12 B. Alternatively, second cap  12 B may be removed and the brewed liquid may be poured or consumed directly from inner tube  11 . 
     Once the brewed liquid has been substantially removed from the interior of inner tube  11 , inner tube  11  may be withdrawn from outer tube  10 . First end cap  12 A may be detached from end  11 A and filter  14  removed from within inner tube  11  for cleaning and/or refilling as desired. 
     A second embodiment of the portable brewing device  200  of the present invention is illustrated in  FIGS. 5 and 6 . In this embodiment, device  200  operates in substantially the same manner as described with respect to device  100 , wherein like elements are represented by the same element numbers. However, in the second embodiment, outer tube  10  does not have a closed end and, instead, has a first open end  10 A and a second open end  10 B. 
     While outer tube  10  of device  200  does not have a closed end, it includes a supply cap  20  removably attached to first end  10 A of outer tube  10 . Supply cap  20  includes means for removably attaching supply cap  20  to first open end  10 A of inner tube  10 . For example, supply cap  20  may include threading for threading engagement with threading on a surface of outer tube  10 . Supply cap  20  may be fabricated with any suitable material having the necessary structural characteristics for its intended purpose. Supply cap  20  includes a pressure valve  20 A to regulate the introduction of liquid into the interior region of outer tube  10 . Pressure valve  20 A may be a quick disconnect valve. Pressure valve  20 A is removably connected to a liquid conduit, such as tubing  21 , which may be coupled to a liquid supply (not shown). The supply cap  20  may include a recess for removably retaining the tubing  21  therein. The supply cap  20  provides a means for introducing hot liquid to the device  200  which minimizes the direct handling of hot water and the risk of burning. 
     With specific reference to  FIG. 6 , device  200  includes access valve  22  removably connected to second cap  12 B at second port  41 B. Access valve  22  may be a one-way valve, such as one-way valve  15  shown with respect to brewing device  100  in  FIG. 3  or the one-way valves used in water bottles, for example, but is not limited thereto. Access valve  22  provides access to the brewed liquid produced by forcing the liquid through the solids contained in filter  14  within inner tube  11 . 
     Device  200  of the second embodiment of the present invention may be operated to make a plurality of batches of brewed liquid without completely removing inner tube  11  from outer tube  10 . Specifically, inner tube  11  may be partially withdrawn from the interior space of outer tube  10 , liquid may be introduced into the interior space of outer tube  10  via tubing  21  and supply valve  20 A, and then inner tube  11  may be pushed down into the interior space of outer tube  10  to force the liquid through the solids in filter  14 . The brewed liquid may then be removed via access valve  22  and the process repeated as desired. Thus, inner tube  11  may need only be removed to replace the solids in filter  14 . 
     Device  200  of the second embodiment may optionally include a webbing/sleeve/tether  25  releasably connecting outer tube  10  and inner tube  11  to prevent outer tube  10  and inner tube  11  from completely separating from each other. Webbing/sleeve/tether  25  is attached to outer tube  10  and inner tube  11  such that the full range of functional motion between outer tube  10  and inner tube  11  is permitted. For example, as shown in  FIG. 6 , webbing/sleeve/tether  25  is attached to first and second range-of-motion limiters  23 ,  24 . As shown, first range-of-motion limiter  23  and second range-of-motion limiter  24  may be collar structures disposed around second end  11 B of inner tube  11  and first end  10 A of outer tube  10 , respectively. Webbing/sleeve/tether  25  releasably connects the first and second range-of-motion limiters  23 ,  24  and may optionally be used as a handle for carrying or securing device  200 . The webbing  25 , sleeve  25 , or tether  25  may be releasably connected to the first and second range-of-motion limiters  23 ,  24 , or another location on the device  200  with one or more quick disconnect fasteners  26 . The quick disconnect fasteners may be release clasps or other suitable coupling devices known to those of skill in the art.