The present invention relates generally to containers and more particularly to a cooling container having a coolant and pressure relief apparatus.
Cooling containers are used to contain a variety of products and maintain such products at a reduced temperature relative to ambient temperature for a prolonged period of time. An example of a cooling container is disclosed in E. L. Smith U.S. Pat. No. 2,526,165, which describes (in connection with FIG. 6 therein) a container having an outer bowl that surrounds an inner bowl wherein the bowls are hermetically sealed to define a chamber therebetween. A suitable refrigerant liquid such as water is disposed within the chamber. A user places the container into a household freezer for a long enough period of time to freeze the liquid. Thereafter, the user takes the container out of the freezer and may place a product, such as a perishable food item, within the container. The refrigerant liquid is capable of maintaining the food item placed in the container at a temperature below room temperature for a relatively long period of time.
Some prior art containers using a coolant or refrigerant within a cavity have included air space within the cavity to allow for expansion of the refrigerant upon freezing. Allowing for such expansion prevents such containers from rupturing. Another strategy to prevent such rupture of a cooling container is disclosed in Hilado U.S. Pat. No. 4,485,636 where the bottom of the cavity is formed by a resilient diaphragm. The diaphragm allows for expansion of the refrigerant by compressing in response to the expanding refrigerant, thereby increasing the volume of the cavity and preventing the walls of the container from breaking as a result of the expanding refrigerant.
While numerous prior art containers deal with pressure increases within a cavity due to expansion of refrigerant upon freezing, no known attempts have been made for handling pressure increases resulting from increased heat. It is possible that if a user were to place a prior art container within a microwave oven, sufficient heat and pressure would develop within the sealed cavity to rupture the walls of the container.
In accordance with one aspect of the present invention, a container comprises a first container portion and a second container portion joined to the first container portion to define a sealed cavity therebetween. A coolant is disposed within the sealed cavity. The container further comprises a pressure relief apparatus operable to limit pressure in the sealed cavity.
According to a further aspect of the present invention, a container comprises a first container portion and a second container portion joined to the first container portion to define a sealed cavity therebetween. A coolant is disposed within the cavity. A joined section joins the first and second container portions. The joined section is operable to limit pressure within the cavity.
A further alternative aspect of the present invention comprehends a container comprising a first container portion having a first wall, a base portion and a first rim. A second container portion has a second wall and a second rim. The second rim is joined to the first rim, thereby defining a cavity between the container portions. A gel is disposed within the cavity. A first raised portion, integral with the second wall, joins the second wall to the base portion and is rupturable in response to a first elevated pressure. A second raised portion, also integral with the second wall, also joins the second wall to the base portion and is rupturable at a second elevated pressure greater than the first elevated pressure.
Referring now to
Any suitable coolant may be disposed within the cavity 51, but preferably the coolant is a cross-linked gel having a generally solid structure such that if the gel were heated the gel matrix tends to remain intact allowing only water vapor to escape from the gel matrix. In operation, the container 36 is first placed in a freezer for a long enough time to freeze the gel. Thereafter, a user may take the container 36 out of the freezer and place products within the interior space 37. The frozen gel should maintain food or other perishable items placed within the interior space 37 of the container 36 within a temperature range between about 10° C. to about 15.5° C. for about four to about six hours in a room temperature environment. In an above room temperature environment, the time and temperature ranges are affected somewhat depending on the ambient temperature. A preferred formulation of the gel comprises a mixture of about 98.2% water and a polymer of about 1.8% to about 2.1% solids. The solids include about 80-85% sodium carboxymethylcellulose, roughly 10-16% sodium benzoate and about 4-6% cross-linkers. The gel is available from Progressive Polymer Application of Sheridan, Wyoming and is sold under the trade name UNIGEL. A small amount of paraben (an anti-microbial preservative) is added to the gel as an additional component of the preferred gel formulation. Of course, other suitable gel formulations may be employed. It should be noted that the container 36 is not limited to use with only perishable food products. Rather, many other products may be kept cool by placement within the container 36. For example, human organs intended for transplant surgery may be placed temporarily therein. Alternatively, a cosmetic product, beverage or chemical compound may be placed in the container 36.
Assembly of the container 36 includes the following steps. The components of the gel are mixed together at room temperature. While still in a liquid state, the gel is poured into the second container portion 42. The first container portion 39 is placed within the second container portion 42, thereby displacing the gel upwardly along the walls of the portions 39 and 42 defining the cavity 51. Within several hours, the gel cures such that it assumes a generally solid structure. Thereafter or before curing of the gel, the joined section 60 is vibration welded to join the base portions 54 and 57. Simultaneously, the rims 45 and 48 are also joined together by vibration welding to seal the cavity 51. However, the respective steps of welding the portions 54 and 57 and of welding the rims 45 and 48 could be performed sequentially.
Referring to
It should be noted that the joined section 60 could alternatively join side portions 73a and 73b (
As described above, the first connection region 63 ruptures in response to elevated pressure to limit pressure in the sealed cavity 51. However, the region 63 could be replaced with a region that alternatively limits elevated pressure by rupturing in response to a different parameter, such as an elevated temperature. By way of example only, a region could be employed that melts below the boiling point of the coolant within the cavity 51. Melting of the region exposes the cavity 51 to the ambient surroundings so that pressure in the cavity 51 is limited. For example, the projection portion 69 might be constructed of a material having such a relatively low melting point that the portion 69 melts in response to such temperature, thereby exposing the opening 72 to the cavity 51. Alternatively, the portion 69 might consist of a material that splinters or cracks in response to such temperature, thereby exposing the opening 72. In such a container, the second connection region 66 would not melt or otherwise rupture in response to the elevated temperature, and as in other embodiments described herein, would prevent possible inversion illustrated in FIG. 5.
Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.
Number | Name | Date | Kind |
---|---|---|---|
1249096 | Hulme | Dec 1917 | A |
3111240 | Whitton, Jr. | Nov 1963 | A |
3460711 | Al-Roy | Aug 1969 | A |
3622016 | Bozek | Nov 1971 | A |
3692208 | Croyle et al. | Sep 1972 | A |
4027776 | Douglas | Jun 1977 | A |
4262815 | Klein | Apr 1981 | A |
4341324 | Ramirez | Jul 1982 | A |
4349119 | Letica | Sep 1982 | A |
4387828 | Yates, Jr. | Jun 1983 | A |
4416388 | Mulawski | Nov 1983 | A |
4426014 | Coltman, Jr. | Jan 1984 | A |
4738372 | Jernberg | Apr 1988 | A |
4747510 | Mack | May 1988 | A |
4765506 | Fishman et al. | Aug 1988 | A |
4844263 | Hadtke | Jul 1989 | A |
4917261 | Borst | Apr 1990 | A |
4974742 | Farrell et al. | Dec 1990 | A |
4986438 | Borst | Jan 1991 | A |
5079932 | Siegel | Jan 1992 | A |
5271244 | Staggs | Dec 1993 | A |
5293997 | Hustad et al. | Mar 1994 | A |
5345784 | Bazemore et al. | Sep 1994 | A |
5361604 | Pier et al. | Nov 1994 | A |
5390797 | Smalley et al. | Feb 1995 | A |
5411158 | Kays et al. | May 1995 | A |
5460286 | Rush et al. | Oct 1995 | A |
5489036 | Arkins | Feb 1996 | A |
5518133 | Hayes et al. | May 1996 | A |
5542234 | Wyslotsky et al. | Aug 1996 | A |
5718124 | Senecal | Feb 1998 | A |
5758793 | Forsyth et al. | Jun 1998 | A |
5806710 | Shiffer et al. | Sep 1998 | A |
5865037 | Bostic | Feb 1999 | A |
5887437 | Maxim | Mar 1999 | A |
5943875 | Hymes | Aug 1999 | A |
5972292 | DeMeo | Oct 1999 | A |
6062040 | Bostic et al. | May 2000 | A |
6068898 | Oyama | May 2000 | A |
6151911 | Dando et al. | Nov 2000 | A |
6209343 | Owen | Apr 2001 | B1 |
6209344 | Mahajan | Apr 2001 | B1 |
6213302 | Sanders et al. | Apr 2001 | B1 |
6216905 | Mogard et al. | Apr 2001 | B1 |
6217136 | Dorfman et al. | Apr 2001 | B1 |
6230924 | Weiss et al. | May 2001 | B1 |
6257434 | Lizzio | Jul 2001 | B1 |
6260729 | Mitchell et al. | Jul 2001 | B1 |
6260731 | Cummings | Jul 2001 | B1 |
6273258 | Piacenza | Aug 2001 | B1 |
6276555 | Edwards | Aug 2001 | B1 |
6283298 | Seidler | Sep 2001 | B1 |
6325234 | Legaspi | Dec 2001 | B1 |
6343709 | DeForrest et al. | Feb 2002 | B1 |
6349820 | Kelley et al. | Feb 2002 | B1 |
6364112 | Pitschka | Apr 2002 | B1 |
6364152 | Poslinski et al. | Apr 2002 | B1 |
6607003 | Wilson | Aug 2003 | B1 |
Number | Date | Country |
---|---|---|
354013046 | Jan 1979 | JP |
WO 9324797 | Dec 1993 | WO |
WO93-24797 | Dec 1993 | WO |
WO 9932373 | Jul 1999 | WO |
Number | Date | Country | |
---|---|---|---|
20030150238 A1 | Aug 2003 | US |