Patent Publication Number: US-2007104838-A1

Title: Package of an infusible substance

Description:
FIELD OF THE INVENTION  
      The present invention relates to packages of infusible substances such as tea and coffee and more particularly to a package which facilitates infusion and has advantages in use.  
     BACKGROUND OF THE INVENTION  
      A popular method of preparing tea and coffee is through the use of soft porous bags containing either tea leaves or ground coffee. In both cases, the soft porous bags may be placed in a cup, mug or other container of heated or boiling water to produce the requisite beverage. In the case of tea bags, it is also usual to place one or more bags in a tea pot so as to provide for a multiplicity of beverages.  
      Once the bag has been immersed in the water for a sufficient time, it is usually removed prior to the beverage being consumed. This typically occurs in the case of cups or mugs of beverage although not usually in the case of tea pots.  
      For the purposes of providing a context for this invention, the following discussion will be directed towards tea, although it will be appreciated that it is equally applicable to other beverages.  
      To ensure that an adequate degree of infusion occurs, it is usual to agitate a tea bag in a container whilst it is immersed in the water in the container. This ensures that there is a sufficient flow of water into and out of the tea bag so as to produce a beverage of adequate strength. For this purpose, it is usual for a string to be attached to a portion of the bag. In this way, the unattached end of the string may be held whilst the tea bag is immersed in the hot water. This allows for the tea bag to be readily agitated whilst immersed and once infusion is complete, for the bag to be removed from the container. Note that it is important for the means for agitation and/or removal of the tea bag be sufficient to minimise the possibility of a user bringing the hands into contact with the hot water in the container.  
      Whilst the string arrangement works reasonably well, it is evident that it has a number of disadvantages. Firstly, in this arrangement, a string must be attached to the tea bag. This is an additional step in manufacture and obviously an additional cost Secondly, although the string facilitates, some agitation so as to assist infusion, it is not usually regarded as adequate should an individual wish to add milk, sugar, cream or the like and disperse the same. Adequate dispersion usually requires the use of a spoon, spatula or other device.  
      The present inventor has recognised that it would be desirable to provide a tea bag or indeed a package of any infusible substance that would be fully functional without the presence of string.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention consists in a package of an infusible substance comprising an elongate structure of a liquid permeable material containing an infusible substance, the structure having a lower portion and an upper portion and being sealed at a lower end and an upper end in a manner such that when the lower portion is immersed in a liquid, the infusible substance is retained substantially within the structure whilst the liquid permeates the infusible substance and the upper portion projects out of the liquid to facilitate gripping thereof.  
      As used in this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.  
      Furthermore, any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of this application.  
     DESCRIPTION OF THE INVENTION  
      It will be appreciated that the present invention is applicable to a variety of infusible substances. In particular tea leaves, herbs and coffee. These substances will be used for producing beverages such as tea, herbal tea, coffee and the like.  
      Depending on the nature of the substance and the requirements of individual beverages, the amount of substance may be varied quite widely. For conventional tea, an amount of about 5-7 g is commonly used.  
      It is usual for the permeable material to be a paper specifically adapted for the purpose of use in pack-ages of infusible material A variety of such papers are well known in the art and the present invention has no particular requirement as to the type of paper chosen.  
      To accommodate a variety of containers, the length of the elongate structure may be similarly varied. For example, the package of the invention could be produced in one form with a length that accommodates drinking vessels, such as cups and mugs and in a second form with a length that accommodates tea pots.  
      For those infusible substances such as tea and herbal teas, the structure may be dimensioned such that swelling of the substance when it is immersed in the liquid results in the formation of a rod like structure. This will occur as the swelling of the substance tends to fill the structure. In this way, the package will take a relatively stiffer form However, it is important to appreciate that whilst this stiffening is desirable, it is by no means essential as the inherent nature of the structure facilitates its use a means for stirring the beverage.  
      As a result of the overall shape and configuration of the package, the immersed surface area thereof in use provides for an efficient exchange between the liquid and the infusible substance. This results in the more rapid preparation of the infusion. Moreover, the rate of infusion is enhanced by virtue of the fact that the package serves as a means for readily sting the infusion.  
      The package in cross section may be varied from substantially circular through to a relatively flat ellipse. Naturally the amount of liquid permeable material used to form the structure will also vary dependent on the cross sectional shape and the overall length. For example, it is feasible to have a structure where the infusible substance is relatively loosely packed. In this example, a relatively larger amount of permeable material would be used and the structure would tend to assume a relatively flat ellipse in cross section. By contrast, in an example where the infusible substance is relatively tightly packed, less of the permeable material would be used and the cross sectional configuration would be closer to circular.  
      It is preferred to form the elongate structure as a tube. The lower end is then sealed and the requisite amount of infusible substance filled into the structure. After filling, an upper end of the structure is then sealed. The person skilled in the art will appreciate that it is desirable for the filling process to be automated and that various machines are available for this purpose. For example, the Italian company IMA SpA manufactures tea bag making machines. Moreover, whilst heat sealing is one means by which the structure may be sealed, other means may be used such as adhesives and crimping.  
      An upper portion of the structure projects out of a liquid in use. This allows for a user to conveniently grip the package thereby facilitating stirring of the liquid and/or removal of the package from the liquid. Usually this portion will be continuous and uniform with the remainder of the structure with the exception that it may be desirable to affix a tag thereto. This tag may function to provide a more suitable surface for gripping and/or as an indicia means. Such indicia may be used to identify the product or carry advertising or the like. In one form the tag maybe affixed to the structure as a single planar sheet. In a preferred form, the sheet may be folded so that it presents opposing planar surfaces arrayed about the structure. This preferred form provides two separate surfaces for carrying indicia as well as providing more convenient gripping surfaces. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      By way of example only, two preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which:  
       FIG. 1  is a top plan view of a first embodiment of a tea package of the invention;  
       FIG. 2  is an inverted plan view of the tea package of  FIG. 1 ;  
       FIG. 3  is an end section view of the tea package of  FIG. 1 ;  
       FIG. 4  is top plan view of a second embodiment of a tea package of the invention; and  
       FIG. 5  is an inverted plain view of the tea package of  FIG. 4 . 
    
    
     PREFERRED MODE OF CARRYING OUT THE INVENTION  
      In  FIG. 1  there is shown one embodiment of a tea package  10  of the invention. Note that in the description that follows, like parts bear the same reference numerals.  
      The tea package  10  comprises a tubular structure  17  which contains tea leaves in an amount of about 5-7 g. As the package is formed of an opaque water permeable paper, the tea leaves cannot be seen in the figures. At lower end  13  and upper end  14 , the structure has been heat sealed. In this embodiment, a quantity of tea leaves has been filled into the structure and the water permeable paper has been dimensioned so that in cross section, the structure approaches a circular shape. This is best seen in  FIG. 3 .  
      As is evident from  FIGS. 1-3 , the tea package  10  is symmetrical about its longitudinal axis. Opposing surfaces  15  and  16  are substantially similar in configuration. By virtue of the amount of tea filled into the structure and the dimensions of the paper used, the opposing surfaces  15  and  16  bulge outwardly towards the centre of the package and then slope towards each other where the surfaces are heat sealed at ends  13  and  14 .  
      The lower portion of the structure generally shown as  11  constitutes that part of the package  10  that would normally be immersed in boiling water. Likewise, the upper portion generally shown as  17  would be used for gripping the package.  
      In  FIGS. 4 and 5 , there is shown a second embodiment of the invention. The features of this embodiment are identical to the first embodiment with the exception of the addition of a tag  21  to the heat sealed upper end  14 . This tag  21  is formed of cardboard which has been folded over sealed end  14  to provide two surfaces for bearing indicia. In this case, the tag has been affixed to the structure by an adhesive applied to one inside surface of the tag. Alternatively, the tag could have been affixed by a single staple passing through both surfaces of the tag and sealed end  14 .  
      It will be appreciated by persons skilled in the art that whilst certain preferred features and embodiments of the invention have described, these are to be considered in all respects as illustrative and not restrictive to the spirit or scope of the invention as broadly described.