1. Field of the Invention
This invention relates generally to self-heating containers and more particularly to self-heating container caps or lids having insertable and non-insertable independent heating chambers or devices whereby heating is initiated by the initiation of crystallization of a super-cooled salt solution stored within the chambers. In particular, the invention utilizes a reliable trigger mechanism to initiate crystallization of the super-cooled salt solution that lends itself to the reuse of the device.
2. Description of the Art
Heat packs utilizing super-cooled aqueous salt solutions as a heating agent are described in the prior art. Various solutions such as sodium acetate and calcium nitrate tetrahydrate are used for this purpose. In the past crystallization has been initialized in such heat packs by the scraping of metal to metal in contact with the super-cooled solution or by the insertion of a crystal into the solution. For example, U.S. Pat. Nos. 4,077,390 and 4,379,448 describe a flexible metal strip trigger incorporating fissures on the surface of the metal or slits in the metal to initiate contact with the salt solution of sodium acetate whereby crystallization is initiated by flexing the strip. U.S. Pat. No. 4,572,158 discloses a trigger comprising a flexible metal sheet having a plurality of activator cuts that extend through the thin sheet material and the shape of each slit includes a first or central slit and a minor slit that extends through the thin sheet material at one end of said first slit and at an angle to the direction of the major slit. Although such triggering devices are used in heat packs, their use along with super-cooled salt solutions in self-heating food and beverage containers is very limited due to a number of factors.
Self-heating containers useful for preparing heated beverages or food are known in the prior art and typically utilize a water-activated or liquid-activated exothermic materials as the heating agent to heat the container rather than a super-cooled salt solution. The process of heat generation in these devices is typically that of a chemical reaction between the materials with subsequent consumption of the reactants and production of products, some of which can be undesirable when made part of a consumer product. For example, U.S. Pat. No. 4,559,921 describes a self-heating vessel that comprises a compartment for the substance to be heated that is adjacent to a sealed container containing a heating agent and water in which one of the materials is sealed in a pouch to keep it separated from the other material. U.S. Pat. No. 5,626,022 discloses a container having a reaction module that contains a solid reactant and a cap module that contains a liquid reactant. Initiation of an exothermic reaction occurs when the two reagents are combined together. U.S. Pat. No. 6,178,753 describes a container equipped with a two-chamber thermal module containing chemical reagents such as calcium oxide and water that are known to produce an exothermic reaction to heat the contents. The container has vents to allow the escape of gas and or steam which is typically generated by the use of exothermic chemical agents.
Such self-heating containers described in the prior art have had limited commercial success. Containers that utilize water-activated chemical heating agents often require complex components, making them expensive and difficult to manufacture. Such water-activated devices are not always reliable because the ingredients fail to properly mix together upon activation or the products of the chemical reaction are toxic or irritating to the user. One particular problem associated with the use of chemical heating agents is the stability of these agents during storage. Mixtures of calcium oxides and calcium chloride, for example, can be effective water-activated heating agents but have a tendency to react prematurely if stored together as a mixture. Self-heating containers described in the prior art that utilize exothermic chemical agents are also not intentionally designed to be recyclable or to facilitate the reuse of the spent chemicals held within, and thus have a reputation of being a wasteful and non-sustainable product and technology.
Self-heating containers that utilize super-cooled aqueous salt solutions as the heating agent in a manner similar to heat packs thus appear to have advantages over water-activated chemical self-heating devices described in the prior art in that only a single, stable chemical is used for heat generation. Here the heat is generated by the phase change that occurs as the super-cooled salt solution changes into a crystallized solid, and no chemical reaction or production of bi-products are involved. Another major advantage of the use of super-cooled salt solutions to generate heat compared to the use of chemical reactants is that the super-cooled material can be regenerated after use from the crystallized salt by heating the material above its melting point in a controlled manner. Self-heating containers that utilize super-cooled salt solutions are thus capable of being re-used or recycled, and are a more sustainable product compared to those devices that use chemical reactants. Such self-heating devices, however, require the use of a triggering mechanism to induce crystallization, and the triggering mechanisms described in the prior art for use in heat packs are not designed for use in beverage and food containers. There is thus a need for a reliable triggering mechanism that can be used to initiate crystallization of a super-cooled salt solution used in a self-heating beverage or food container that is simple to use, low cost and capable of allowing the reuse or recycling of the container or the heating agent.
With respect to the above, it is important for commercial success of any self-heating container that it can be utilized within the preferred processes for making beverages and food. For example, many beverages must be pasteurized before being sealed in a container so that bacteria growth is eliminated and spoilage of the consumable item is minimized. Beverages such as milk, coffee drinks and the like are pasteurized in the body of the container before the lid is fixed to the container, so any self-heating embodiment should be compatible with the existing pasteurization processes and not involve addition process steps.
Self-heating containers should also be manufactured using conventional manufacturer materials and equipment with minimal adaptation. For example, in U.S. Pat. No. 4,784,678 a container comprised of an outer compartment for holding a beverage and an inner compartment for holding a heating or cooling agent is shown that can be manufactured with conventional can manufacturing technology. Here the container is made by first pre-forming the outer compartment such that it can be used to enclose a beverage during pasteurization and then pre-forming the inner compartment, as an integral part of the can lid or as a separate chamber, inserting the heating or cooling agent into inner the compartment and then inserting the completed inner compartment into the outer compartment. The lid of the sealed container thus has a portal to access the inner compartment containing the heating or cooling agent and a portal to access the beverage, and can be made with conventional lid manufacturing techniques and affixed to the container using conventional technology.
In a similar manner, U.S. Pat. No. 5,255,812 discloses caps that contain heating or cooling agents that can be fixed to the tops of containers to provide a means of changing the temperature of the contents of the containers. It is thus evident from the prior art that it is advantageous to incorporate a self-heating device and especially a device that utilizes a super-cooled salt solution as the heating agent, into the caps or lids of containers rather than into the main body of the container in order to be compatible with existing beverage processes and container-manufacturing technology. Such an incorporation, however, must be designed to minimize contact between the heating agent and the beverage. However, at the present time, none of these prior self-heating containers, lids or caps have met with commercial success.
In order to be commercially successful, self-heating containers must embody several attributes in addition to being adaptable to current container manufacturing techniques and processes. It is essential that: the heating mechanism must be safe, simple, inexpensive and efficient; the actuation technique for initiating the heating process must be tamper-evident and simple in order to appeal to the consumer; and the device must facilitate and encourage the environmentally safe reuse or recycle of the spent heating agent. Self-heating containers, lids and caps shown in the prior art have not had one or more of the above attributes.
It is an object of the present invention to provide a container equipped with a cap or lid coupled to a self-heating device and method which can efficiently and safely heat beverages prior to consumption.
It is another object of this invention to provide a cap or lid containing a self-heating device which can manufactured without major alterations in manufacturing machinery or equipment.
It is another object of this invention to employ an exothermic process with safe and inexpensive materials as a self-contained heating mechanism.
It is yet a further object of this invention to provide a cap or lid containing a self-heating device which can be easily and safely actuated to initiate the heating process.
Still a further object of this invention is to provide a cap or lid containing a self-heating device that can facilitate and encourage the environmentally safe reuse or recycle of the heating agent held within.
Accordingly, the present invention provides a self-heating container comprising:
(a) a closure means, typically flat like a lid or shaped to fit over an opening or portal, having dimensions such that the closure means can cover and enclose an outer compartment containing a beverage to be heated and form the top end of the outer compartment whereby the compartment also has at least one sidewall and a bottom end whereby the sidewall, lid or cap and the bottom end form a first cavity for storing a liquid. Here the lid is coupled to a self-heating device and is directly and permanently attached to the outer compartment.
(b) a closure means, typically a threaded cap shaped to fit over an opening or portal, having dimensions such that the closure means can cover and enclose an outer compartment containing a beverage to be heated and form the top end of the outer compartment whereby the compartment also has at least one sidewall and a bottom end whereby the sidewall, cap and the bottom end form a first cavity for storing a liquid. Here the cap is either permanently coupled to a self-heating device or to a well that can contain the self-heating device, or can be screwed onto the outer compartment to make contact between the lip of a self-heating device that lies on top of the first cavity such that a leak-free seal is formed between the cap, the lip of the self-heating device and the outer compartment. The cap is not permanently attached to the outer compartment but can be unscrewed and removed to access the beverage in the first cavity of the outer compartment and also screwed back on to seal off the first cavity when desired.
(c) an openable closure means located on, adjacent to incorporated within the surface of the lid of the outer compartment such that the means can be penetrated or opened or removed to provide access to the liquid stored within as is the case for a beverage can; or alternatively, the cap itself comprises an openable closure means as is the case for a beverage bottle.
(d) a self-heating device comprising an inner compartment having a smaller diameter and volume than the outer compartment and incorporated into or coupled to the cap or lid forming the top end of the outer compartment such that the inner compartment can be located within the cavity of the outer compartment when the cap or lid containing the inner compartment is affixed to the outer compartment, said inner compartment including: (i) at least one sidewall, a top end and a bottom end, (ii) a second cavity containing a heating agent consisting of a super-cooled salt solution that exists as a liquid in its pre-activation state, (iii) an openable closure or tear panel or means attached to the bottom end that provides tamper-free access to the inner compartment while preventing accidental activation of the heating mechanism, (iv) a structure or fixture in the form of a concentric ring that is attached to the interior sidewall of the inner compartment at the bottom quadrant of the compartment that is designed to rigidly hold the trigger in place such that it is in contact with the heating agent and positioned to be struck by an actuator means, (v) an actuator means comprising a solid rod-like or cylindrically shaped piece having an etched, pock-marked or roughened surface with a sharpened end, (vi) a trigger formed from a thin metallic strip having an etched, pock-marked or roughened surface which is bendable with snap displacement and having a centrally located crystallization strike zone consisting of an orifice with a saw-toothed patterned inner diameter, (vii) a flexible diaphragm attached to or comprising the bottom end of the inner compartment and accessible through the openable closure or tear panel having an interior-oriented surface and an exterior-oriented surface whereby the interior-oriented surface is affixed to the rod-like actuator and (viii) a heating mechanism comprising the compressible diaphragm attached to the actuator means that is activated by compressing the diaphragm towards the interior of the inner compartment to allow the actuator means to strike against the saw-tooth surfaces of the trigger in the strike zone, scraping against those surfaces while simultaneously causing the metal strip of the trigger to bend with a snap displacement such that the forces released initiate the crystallization of the super-cooled salt solution, thus releasing heat to heat up the beverage or food stored in the first cavity of the container.
With respect to the same self-heating container, the diameter of the rod-like actuator is approximately the same as the diameter of the orifice contained within the trigger as measured at the base of the saw-toothed edges of the orifice, and the surfaces of the actuator and trigger are etched, pock-marked or roughened such that upon activation the actuator surface will rub against the saw-toothed edges of the trigger and compress the solution trapped between the surface deformities of the actuator and the edges of the trigger, initiating crystallization. Crystallization is further enhanced when the trigger is subjected to flexing or bending whereby the surface deformities present in the roughened and etched surface of the trigger are strained such that minute cracks and continuances are formed within the deformities that impart stresses to the super-cooled salt solution in intimate contact with the trigger surface, thus facilitating the crystallization process.
According to an embodiment of the invention, a self-heating container as described above that is affixed to the cap or lid containing the self-heating device may have a layer of insulation is affixed to the interior or the exterior surface of the sidewall of the outer compartment.
According to another embodiment of the invention, a lid containing the self-heating device as described above that also serves as a covering of the top end of a self-heating beverage container as described above has an openable closure means on the surface of the top end of the outer compartment comprising a rupturable tear panel or pull tab which may be ruptured to provide access to the liquid stored within the first cavity whereby (i) the pull tab has a front end and a bottom end and (ii) the back end of the pull tab is placed adjacent to the rupturable tear panel such that when the front end of the pull tab is pulled away from the top end of the outer compartment, the rupturable tear panel ruptures and moves into the first cavity, provide access to the liquid stored within.
According to another embodiment of the invention, a self-heating container as described above has an openable closure means consisting of a cap that can be firmly attached to top end of the outer compartment to form a sealed unit comprising: (i) a threaded cap equipped with a female-threaded fitting or other female-threaded means having an exterior surface and an interior surface such that the cap when screwed onto the self-heating container will create a self-contained unit, (ii) a seal or gasket affixed to the interior surface of the cap that can also cover the opening of the outer compartment to create an isolated first cavity within the outer compartment that can contain any enclosed beverage or liquid without leakage or spillage and without any contamination from the environment even when the liquid is pressurized under those pressures typical of a carbonated beverage, (iii) a top end of the outer compartment equipped with a male-threaded fitting or other male threaded means that can mate with the threaded cap when screwed together to form a tight-fitting seal between the cap, the gasket, the top end of the outer compartment and the first cavity of the outer compartment.
According to another embodiment of the invention, a lid or cap as described above is directly and permanently attached to the inner compartment of the self-heating device which is then in direct contact with the liquid contained within the outer compartment and located within the first cavity of the outer compartment. As shown above, the inner compartment is self-contained without any seals or penetrations between the contents of the inner compartment and the contents of the first cavity of the outer compartment so that contamination of a beverage with heating agent is virtually eliminated. With respect to the inner compartment, the flexible diaphragm is affixed to the bottom of the inner compartment to create a completely self-contained unit that can be activated by the consumer with no contact between the consumer and contents of the inner compartment. As an additional safety feature, the flexible diaphragm and contact interface with the consumer with respect to activating the heating mechanism is completely separated from the pull tab at the top of the container whereby the consumer accesses the beverage. By these features, the cap or lid attached to a self-heating device and the corresponding self-heating container is made safe to use.
According to another embodiment of the invention, the surface of the cap or lid is expanded to form a well that can extend into the interior of the first cavity, when the lid or cap is secured to the outer compartment, to displace some of the volume of the first cavity that contains the liquid to be heated up such that a third cavity is formed that does not contain any liquid and is open to the environment. The third cavity conforms to the shape of the inner compartment and is made to hold the inner compartment in place. The inner compartment can be held in place within the lid or cap by a pressure seal attached to the circumference of the bottom end of the sidewall of the inner compartment or by modifying the bottom end of the sidewall to form a male threaded fitting that can be screwed into a female threaded fitting formed as a modification of the bottom expanded end of the outer container. In this manner a separate heating device or insert that comprises the heating mechanism and the heating agent can be manufactured separately from the cap or lid of the container holding the beverage to be heated, and thus the described heating device can be inserted into and removed from the cap or lid and thus indirectly from a beverage container for ease of use and to promote efficiency with respect to the manufacturing of the lid, cap, container and the device and with respect to the recycling and reuse of the lids, caps, containers and the spent heating materials.
According to another embodiment of the invention, the sidewall adjacent to the top end of the inner compartment of the self-heating device as described herein is modified to form a lip or concentric ring that extends outward perpendicular to the vertical axis of the sidewall of the inner compartment. The lip has a top surface, a bottom surface, and a gasket attached to the bottom surface of the lip, and is extended such that the bottom surface of the lip forms a leak-free seal of the first cavity when the modified self-heating device is placed into the first cavity of the outer compartment and onto the top of the outer compartment of a beverage container and downward pressured is applied to the top surface of the lip. This downward pressure can be applied by screwing on any standard cap or lid that is typically used to seal a beverage or food container which is typically a glass or plastic bottle. In this manner a separate heating device or insert can be manufactured and sold separately from the cap or lid and the container holding the beverage to be heated, and thus the described heating device can be inserted into and removed from a beverage bottle or other related container having a cap or a lid without the need for a specially modified cap, lid or self-heating container for ease of use and to reduce the cost of use.
The lid or cap containing the self-heating device when used as part of a self-heating container disclosed herein thus provides several additional benefits, some of which are detailed below. For example, since self-heating beverages do not have to be heated using an external heating source to provide a heated liquid, their use may reduce the cost borne by retailers of beverage containers to heat up the beverage prior to use. Self-heating beverage containers may similarly reduce or eliminate the need for vending machines that heat up the beverage prior to dispensing it to the consumer. Lid and caps containing the self-heating devices are also easier and less costly to manufacture compared to self-heating containers where the self-heating device is part of the body of the container instead of the cap or lid. Self-heating devices that can be used with any standard beverage bottle without modification of the bottle or cap or lid are particularly advantages with respect to cost and ease of use and time to market.
The objects of the present invention and the associated advantages thereof will become more readily apparent from the following detailed description when taken in conjunction with the following drawings in which:
With reference to the drawings,
With further reference to
Alternatively, and in reference to
With further reference to
With reference to
The trigger 20 has a centrally located crystallization strike zone 32 consisting of an orifice 33 with a saw-toothed patterned inner configuration 34 of approximately ¼th to ⅜th inch in diameter at the base of the saw-teeth 35. The entire surface of the trigger 20 is etched, pock-marked and roughened such that some of the surface deformities are deep enough to penetrate through the strip of metal, forming pin-holes and cracks 36 in the trigger 20. The surface is roughened by a process known by those in the art sufficient to create the deformities without so weakening the mechanical integrity of the metal to cause it to break apart when flexed by the actuator 22.
The trigger 20 is secured in place within the lower quadrant of the inner compartment 18 by the fixture 21 which is in turn attached to the inner sidewall 27 of the inner compartment 18 at a location approximately 1 inch above the bottom end 29 of the inner compartment 18. The fixture is a concentric ring shape approximately ¼th inch to ½ inch in width and thickness having two rectangular support members 31 of approximately ¼th inch to ½ inch in thickness and ½ inch in width extending outwards from the circumference of the concentric ring to attach to opposite ends of the trigger 20, thus securing the trigger 20 within the center of the fixture 21. The trigger 20 is attached to the each of the two support members 31 by any method known to those experienced in the art including by gluing, pinning or clamping. The fixture 21 and the attached supports 31 can be fabricated of metal, plastic or any other suitably rigid material.
With further reference to
The surface of the actuator 22 is etched, pock-marked or roughened such that upon activation the actuator surface will rub against the saw-toothed edges 37 of the trigger 22 and compress the solution 19 trapped between the surface deformities of the actuator 22 and the edges 37 of the trigger 20, initiating crystallization. The surface is roughened by a process known by those in the art sufficient to create the deformities without so weakening the mechanical integrity of the actuator 22 such that it would break apart upon activation.
With further reference to
As shown in
With respect to the inner compartment 18, the flexible diaphragm 23 is affixed to the bottom of the inner compartment 18 to create a completely self-contained unit that can be activated by the consumer with no contact between the consumer and contents of the inner compartment 18. As an additional safety feature, the flexible diaphragm 23 and contact interface with the consumer with respect to activating the heating mechanism is completely separated from the pull tab 6 at the top of the container 5 whereby the consumer accesses the beverage 16. By these features, the self-heating container 5 is made safe to use.
With further reference to
The caps 4 or lids 3 containing the heating device 46 can all be manufactured separately from the container 5 holding the beverage 16 to be heated, and thus the described heating device 46 can be inserted into and removed from the beverage container 5 for ease of use and to promote efficiency with respect to the manufacturing of the container 5 and the device 46 and with respect to the recycling and reuse of the container 5 or the insert 46. The insertable device 46 facilitates reuse of the heating materials 19 in that the device 46 containing the heating materials 19 can be removed after use and slowly warmed to melt the crystallized salt above the melting temperature of the salts in such a manner as to make a stable super-cooled salt solution 19. The device containing the super-cooled salt solution 19 is then ready for use as a thermal agent 19 to be inserted into the self-heating container 5.
With respect to the above, the operation of the present self-heating container 5 equipped with a lid 3 or a cap 4 containing a self-heating device 46 or the self-heating device 46 used as an insert is safe and simple. A customer first pulls away the tear panel 24 located at the bottom of the container 5 to gain access to the heating mechanism, applies pressure to the flexible diaphragm 23 with a finger thereby causing the force to be exerted upon the actuator means 22 and driving the actuator 22 to scrape against the trigger 20 at the strike zones while causing the trigger 20 to bend with a snap displacement. This action initiates crystallization of the super-cooled salt solution 9 in the inner compartment 18 with the corresponding release of heat to the beverage 16 stored in the first compartment 15 of the container 5, thus heating up the beverage 16. The beverage is consumed through the openable closure means 17 by pulling on the pull tab 6 or unscrewing the bottle cap.
Alternatively, the consumer may remove the cap 63 from a standard beverage bottle 62, which typically contains an airspace at the top, select a self-heating device 46equipped with a lip 58, activate the heating mechanism of the device in the same manner as above, insert the self-heating device 46 into the opening at the top of the beverage container 62, and then tightly attaché the cap 63 and wait for the beverage 16 to heat up sufficiently for consumption. The consumer can then remove the cap 63 and the device 46 and consume the beverage 16.
After consuming the beverage 16, the consumer may then recycle the self-heating container 5 as a unit or as in one embodiment, remove the heating device 46 from the self-heating container 5 and recycle the heating device 46 and the remaining component of the self-heating container 5 separately. In another preferred embodiment of the invention, the consumer may warm up the device 46 to restore the super-cooled salt solution 19 from the crystallized salt, refill the container 5 with a beverage 16, insert the device 46 into the container 5, activate the device 46 as described herein and heat up the beverage 16. In this embodiment, the invention can be reused for its intended purpose, reducing waste.
While the preferred form of the present invention has been shown and described above, it should be apparent to those skilled in the art that the subject invention is not limited by the Figures and that the scope of the invention includes modifications, variations and equivalents which fall within the scope the attached claims. Moreover, it should be understood that the individual components of the invention include equivalent embodiments without departing from the spirit of this invention.
This application claim priority to provisional Patent Application Ser. No. 61/473,016, filed Apr. 7, 2011, the disclosure of which is incorporated herein by reference
Number | Date | Country | |
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61473016 | Apr 2011 | US |