Abstract:
An end disk construction and connection for food sauce dispensing cartridges and other food containers. An end disk through which food sauce may be dispensed is fitted in the dispensing end of a cartridge that holds the sauce. The disk initially has a projecting peripheral skirt which fits against the side wall of the cartridge. The end portion of the cartridge wall is crimped inwardly to fold the skirt into a lip which is doubled over on the peripheral area of the disk. The flange formed by the inwardly folded wall portion encloses the lip and its raw edge to isolate the edge from the food sauce. A bond is effected between the disk and the cartridge wall and flange by thermoplastic coating on the disk and cartridge body which is heated during the crimping process.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to the dispensing of food sauces and other foods and more particularly to an improved end construction for sauce dispensing cartridges. 
     BACKGROUND OF THE INVENTION 
     Fast service restaurants and other food service facilities use various types of food sauces that are applied to sandwiches and other foods. Due to the large volume of customers that are served by fast service restaurant chains, the sauces must be dispensed repeatedly in carefully controlled portions each containing a relatively small amount of sauce. Particularly in applications of this type, it has proven to be convenient for the sauces to be packaged in cartridge dispensers from which the sauce is dispensed using handheld dispensing guns. The amount of sauce that is dispensed is controlled by providing suitable valving in the dispensing end of the cartridge and using a dispensing gun that advances a plug in the cartridge a consistent distance each time the dispensing gun trigger is squeezed. 
     Examples of the type of dispensing cartridges that have been used include U.S. Pat. No. 4,432,473 to MacEwen and U.S. Pat. No. 4,830,231 to Smith. Although cartridges of this type have functioned well for the most part, there is room for improvement, particularly with respect to the construction of the bottom disk and its connection with the body of the cartridge. 
     It has been common practice in the past to use “hot melt” adhesive to glue the end disk to the inside of the cartridge wall. Such adhesives are typically applied to the inside surface of the disk and cartridge wall where they are in contact with the food sauce contained by the cartridge. Accordingly, the adhesive must meet food grade standards. Such adhesives are relatively expensive and also complicate the manufacturing process due to the need for the adhesive to be heated and accurately applied. The adhesive must be applied in a bead or fillet completely around the periphery of the disk in order to prevent leakage of sauce past the edge of the disk. Also, the raw edge of the disk must be isolated from the sauce by the adhesive in order to prevent the sauce from “wicking” into the paperboard edge of the disk. Many adhesives do not exhibit good temperature or chemical resistance properties, which limits the types of products that can be packaged in the cartridge. The end disk constructions that have been used in the past in dispensing cartridges normally recess the disk a significant distance inwardly from the end of the cartridge body. Because the food sauce can be filled only to the end disk, the volume of the cartridge body located beyond the disk is unavailable to hold the sauce. When pressure is applied to the end disk during dispensing of the sauce, the disk can bow or otherwise deform because of the relatively weak construction of the disk itself and particularly its connection with the cartridge body. This flexure can create problems in the dispensing of the sauce. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a food sauce dispensing cartridge that has an improved end disk construction. More specifically, the invention is characterized by an end disk that is initially positioned inside the dispensing end of the cartridge body with a peripheral skirt lying along the inside of the cartridge body wall and the end portion of the cartridge wall extending beyond the skirt. The wall end portion is crimped or folded inwardly to lie along the outwardly facing surface of the end disk. This folds the skirt into the form of a lip which is doubled over onto the peripheral portion of the disk. Heat is applied during the crimping process to melt the thermplastic which coats the surfaces of the disk and cartridge wall. When the thermoplastic cools, it forms an effective heat seal between the disk and the cartridge body. 
     The folded or crimped end portion of the cartridge wall provides an in turned flange which is heat sealed to the lip on the disk and to the main disk surface. The disk sandwiches the lip and its raw edge between the main disk surface and the flange so that the raw paperboard edge of the disk is enclosed. This isolates the disk edge from the product contained within the cartridge body. Further, a strong connection is provided because the fold on the periphery of the disk is heat sealed to the cartridge wall and the flange on the cartridge body is heat sealed to the lip and to the main surface of the disk. The folded over lip provides an extra layer of paperboard at the connection area, and the flange provides still another layer of material that strengthens the connection and reduces the tendency for the end disk to bow or otherwise deflect when the sauce is being dispensed. 
     This construction eliminates the need for costly “hot melt” adhesive and also provides better temperature and chemical resistance than cartridges that use such adhesives. The cartridge has a substantially flat end configuration so that the disk is adjacent to the end of the cartridge body, thus making the entire length of the cartridge available to hold the food sauce. Wicking of the food sauce into the raw edge of the disk cannot occur because the disk edge is completely enclosed by the folded flange. The overall result is that the dispensing cartridge is economical to make, exhibits good temperature and chemical resistance, has enhanced strength, and provides more volume than cartridges with recessed end disks. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views: 
     FIG. 1 is a side elevational view of a food sauce dispensing cartridge constructed according to a preferred embodiment of the present invention, with the cartridge applied to a dispensing gun and a portion of the cartridge wall broken away for purposes of illustration; 
     FIG. 2 is a fragmentary sectional view on an enlarged scale showing the detail identified by numeral  2  in FIG. 1; and 
     FIG. 3 is a fragmentary sectional view similar to FIG. 2, but showing the end disk applied in the end portion of the cartridge prior to the cartridge end being folded or crimped inwardly and heat sealed to complete the end construction of the cartridge. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings in more detail and initially to FIG. 1 in particular, numeral  10  generally designates a food sauce dispensing cartridge constructed in accordance with a preferred embodiment of the present invention. Food sauce  12  is packaged in the cartridge  10  and is dispensed in measured quantities from the cartridge by a handheld dispensing gun  14 . The dispensing gun  14  has a pair of flanged plates  16  between which the cartridge  10  is held. The dispensing gun  14  has a handle  18  and a trigger  20  which may be squeezed to operate the dispensing gun. A pawl  22  is connected with the trigger  20  and acts against a ratchet  24  when the trigger  20  is squeezed. The ratchet  24  takes the form of a bar which carries a plunger  26  on one end. Each time the trigger  20  is squeezed, the interaction between the pawl  22  and ratchet  24  advances the plunger  26  into the cartridge  10  a predetermined distance in order to dispense the food sauce  12 . The construction and operation of the dispensing gun  14  is described in more detail in U.S. Pat. No. 4,432,473 to which reference may be made for a thorough description of the dispensing gun. 
     The dispensing cartridge  10  has a body  28  which is formed by a cylindrical side wall  30 . The side wall  30  is preferably a foil laminated food grade paperboard that is coated on both its inside and outside surfaces with thermoplastic  31  (FIGS.  2  and  3 ), preferably polyethylene. The body  28  may be formed by rolling the paperboard into the shape of a cylinder and providing an overlap or seam area (not shown) which is suitably secured to form a leakproof container. 
     One end of the cartridge body  28  is provided with a plug  32  which closes the end of the cartridge and may be advanced into the cartridge body toward the opposite end when the plunger  26  of the dispensing gun is advanced against the plug. 
     The opposite end of the cartridge body  28  is the end through which the sauce  12  is dispensed. The dispensing end is provided with an end disk  34 . The disk  34  may be provided with one or more valve openings  36  through which the food sauce  12  is dispensed each time the plug  32  is advanced toward the end disk  34  through operation of the dispensing gun  14 . The food sauce  12  is discharged through the outlet or outlets  36  in a precise amount that is dependent upon the distance the plug  32  advances when the dispensing gun is operated. The plunger  26  is advanced a consistent amount each time the trigger  20  is squeezed, so that the same amount of food sauce  12  is discharged through the outlet or outlets  36  each time the dispensing gun is operated. 
     The present invention relates to the construction of the end disk  34  and the manner in which it is connected with the side wall  30  of the cartridge body  28 . With reference to FIG. 3 in particular, the end disk  34  is initially provided in the form of a flat circular panel having a peripheral skirt  38  turned from the main body of the disk  34  at a 90° angle. The diameter of the disk  34  is such that the skirt  38  fits closely against the inside surface of the cartridge wall  30  when the disk is inserted into the dispensing end of the cartridge body  28 . The disk  34  and skirt  38  are preferably constructed as an integral unit, with the skirt  38  bent from the peripheral edge portion of the disk body. The skirt terminates in an edge  39  that is typically at lest partly paperboard. Preferably, the disk  34  and skirt  38  are constructed of foil laminated food grade paperboard coated on both surfaces with thermoplastic  37  such as polyethylene. 
     The disk  34  is initially positioned inside of the cartridge side wall  30  at the approximate location shown in FIG.  3 . The disk  34  is recessed a selected distance inwardly from the end of the cartridge body  28  such that an extending end portion  40  of the side wall  30  extends beyond the location of the main body of the disk  34  and the edge  39  of the skirt  38 . 
     With the disk  34  located in the position of FIG.  3  and held in that position, the extending end portion  40  of the side wall  30  is crimped or folded radially inwardly until it lies along the outwardly facing surface  34   a  of the end disk  34 . After the crimping operation has been completed, the inwardly folded end portion  40  of the side wall  30  is formed into a flange  42  as shown in FIG.  2 . The flange  42  is crimped or folded inwardly about a shoulder  44  which is located close to the disk  34  at the intersection between the main portion of the side wall  30  and the inwardly turned flange  42 . 
     With continued reference to FIG. 2 in particular, crimping of the flange  42  inwardly from the side wall  30  results in the skirt  38  being folded inwardly or doubled back onto the exposed or outwardly facing surface  34   a  of the disk  34  to form a folded lip  46 . The lip  46  provides a double layer of material at the location of the connection between the disk  34  and the cartridge body  28 . The lip  46  is doubled back onto the disk  34  at a fold  48  located adjacent to the end of the side wall  30  immediately inwardly of the crimped shoulder  44 . 
     Before flange  42  has been crimped inwardly, heat is applied to the flange  42 , the adjacent area of the side wall  30  and to the peripheral area of the disk  34  and the lip  46  and fold  48 . The application of heat causes the thermoplastic coating  31  on the inside of the side wall  30  and flange  42  to melt, and it also causes the thermoplastic coating  37  on the peripheral area of the disk  34  and the lip  46  and fold  48  to melt. When the cartridge thereafter cools, the thermoplastic creates a heat seal and bonds the flange  42  to the lip  46  and the adjacent outer surface of the disk  34 , as shown in FIG.  2 . In addition, the fold  48  is sealed to the inside of the end of the side wall  30  and the inside of the crimped shoulder  44 . The end of the flange  42  extends inwardly beyond the edge  39  of the disk and is heat sealed and bonded to the main body of the disk  34  at a location inwardly from the edge  39 . The lip  46  and edge  39  are thus enclosed between the flange  42  on one side and the main body of the disk  34  on the other side. The seal of the fold  48  against the side wall  30  and the inside of the shoulder  44  isolates the edge  39  from the food sauce  12  contained within the cartridge body  28 . The thermoplastic  31  and  37 , after it has melted and cooled, creates a bond between the flange  42  and the lip  46  and disk  44 , and a similar bond is created by the thermoplastic between the fold  48  and the cartridge side wall  30  and shoulder  44 . This bond creates an effective seal of the interior of the cartridge and also a strong connection between the cartridge body  28  and the disk  34 . In addition to the overlap or double layer provided by the in turned lip  46 , the in turned flange  42  provides another layer of material that reinforces and strengthens the peripheral area of the disk  34  and its connection with the cartridge body  28 . As a result, the disk  34  is better able to resist a tendency to bow or deflect when it is subjected to pressure during dispensing of food sauce  12 . 
     The disk  34  is located adjacent to the dispensing end of the container side wall  30 . Therefore, the cartridge  10  presents a flat end construction, and substantially the entire length of the cartridge body  28  is available to hold the food sauce  12 . It is noted that the end disk construction and connection arrangement of the present invention eliminates the need to use “hot melt” adhesive or other adhesives in order to secure the end disk in place. This reduces the cost to manufacture the cartridge and also provides the cartridge with better temperature and chemical resistance which is inhibited by the need for hot melt adhesives in cartridges that have been used in the past. 
     Although the invention has been described in connection with an end construction for a cartridge dispenser for food sauce, it has utility in other applications that involve the packaging of foods. For example, the end construction may be used for the bottom of a food container or the lid of for a food container. 
     From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. 
     Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.