Cooling package and sensor probe

A cooling package that includes a sensor that provides a signal to the user to indicate that the cooling package is ready for use and when the cooling package is depleted is described. The sensor and sensor display are selected on the basis of the freezing point of the contained solution. The freezing point of the solution is adjustable through use of organic or inorganic additives. The sensor can further be used by placement directly in contact with a food product and through measurement of temperature, pH or electrical conductivity a signal to the user through the built in display warns of food spoilage if the temperature, cumulative time above a pre-selected temperature, pH or electrical conductivity exceed a pre-selected limit.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

Not Applicable.

BACKGROUND OF THE INVENTION

Technical Field

The invention generally relates to the fields of portable cooling packages such as ice packs used for food storage.

Background of the Invention

The use of cooling packs ranging from simple blocks or bags of ice to portable electronic refrigerators are common for preserving foods and drinks when travelling, camping, tailgating or other activities away from a home based refrigerator. Leaving food out too long at temperatures above 0 to 40° C. can cause bacteria, such asStaphylococcus aureus, Salmonella Enteritidis, Escherichia coli, andCampylobacter, to grow to dangerous levels that can cause illness. The use of cooling packages that include a container, typically made of a thermoplastic material, and, filled with an aqueous solution that in many cases further includes either organic additives or inorganic salt additives to lower the freezing point are common. The cooling packages may be pre-filled with a cooling solution or filled by the user and placed into a home freezer to attain a cold temperature prior to use in a cooler or other portable package for food storage. All too frequently, such cooling packages, however, do not provide reliable cooling and therefore food preservation. The cooling capacity of the packages rely on both the heat of fusion of the solution contained inside as well as the heat capacity of both the solid and liquid forms of the cooling solutions contained within and the package material itself. By far, the most significant cooling capacity comes from the heat of fusion of the solution. Full cooling capacity requires that all of the solution within the package is frozen solid. Opacity and stiffness of the cooling package frequently makes it difficult or impossible to tell whether the solution is fully frozen to provide full cooling capacity.

Additionally, during use, it is difficult to tell how much cooling capacity remains. Once all of the solid cooling solution has melted the temperature within a cooler can rise rapidly. Predicting when the cooling package will be, or, has been “depleted”, and, the container being cooled by the cooling package becomes unsafe to preserve foodstuff is difficult to determine by just look and feel.

Frequently a user of such cooling packages will want to be able to adjust the cooling temperatures. Storing beverages in a cooler that is too cold can result in freezing of the beverages and perhaps even breakage of the beverage container. However, for longer term storage of food products, such as for a long camping trip, a much colder, even sub-freezing temperature may be required to keep the food safe for consumption. However, without properly freezing the package prior to use, the full cooling capacity of the cooling package will not be realized.

Frequently a user will also want to be able to adjust both the temperature and the size of the cooling package.

There is a need for a cooling package that includes an accurate indicator that the package is ready for use. There is a need for a cooling package that includes an accurate indicator that the cooling capacity of the cooling package is depleted. There is a need for a cooling package that has an adjustable target temperature, and, the indicators of ready to use and remaining capacity for any of the selected target temperatures. There is a need for an indicator and sensor probe that can be used by the user to tell that a stored food product has been too warm for too long a length of time, and, is, in fact, now unsafe for consumption.

BRIEF SUMMARY OF THE INVENTION

The invention includes a collapsible cooling package that is filled with a fluid and placed in a freezer compartment of a refrigerator until ready to use. The invented cooling package includes a sensor probe that extends into the interior of the cooling package that is attached to a display that is incorporated into the screw cap of the collapsible cooling package. In a preferred embodiment the sensor is a temperature sensor and the display shows the temperature of the contents of the cooling package at the distal end of the sensor probe. The sensor probe is sized to terminate at the point in the package that is known to be the last to freeze. In this way the temperature on the display is an indicator when the entire cooling package is fully frozen and ready for use. In a preferred embodiment the temperature, with the probe so placed, indicates the entire package is in the range of 0 to 5° C. The display includes indicia that show the temperature within the cooling package and indicia showing safe and unsafe conditions for food storage. In another embodiment a method for using the cooling package includes adding a fluid within the cooling package, the fluid having a pre-selected freezing point that corresponds to an indicia on the display, such that the sensor, display, and, fluid are custom selected for a particular pre-selected operating range of the cooling package. In one embodiment the fluids include pre-selected mixes for a first lower temperature for frozen storage of (preferably 0° C.) and a second higher temperature for food storage (preferably 4° C.). In another embodiment, the fluid for the cooling package, the sensor probe, and, the display are all preselected for operating temperature of a particular range. In another embodiment, the fluid for the cooling package, the sensor probe, the display, the amount of fluid and the size of the cooling package are all preselected for operating temperature of a particular range and cooling for a particular time duration. In one embodiment the size of the package is adjusted by collapsing or expanding a package with accordion walls.

Another embodiment further includes an electronics module operably placed between the sensor probe and the display. In one embodiment the sensor probe is one selected from a temperature probe, a pH probe, and, an electrical conductivity probe, and, the electronics module is programmed to accept an electrical signal from the probe and compare that signal against pre-selected limits that are indicative of food spoilage. In one embodiment the electronics are incorporated into a screw cap and use a sensor probe sized and adapted to fit a milk container and the electronics module is further programmed to cause the display to show an alarm signal indicative of milk OK to use and milk that is spoiled.

DETAILED DESCRIPTION

The present invention provides according to one or more of the following embodiments, systems, hardware, and related methods for easy to use cooling packages that include sensors for improved performance of the cooling package and enhanced food storage safety. The details of the embodiments describe of the use of the sensor primarily in a cooler package that is frozen in a home freezer for use in portable insulated containers as are known in the art. One example is shown of using the sensor in the food package itself to detect spoilage. Commonly numbered items in all the Figures refer to the same item or functionality throughout the description, although the item may not be identical in all applications.

FIG. 1shows a perspective view of a cooling package100. The cooling package includes a container105that is typical made from a molded or blow molded thermoplastic material that includes walls that include accordion ridges101. The ridges provide increased surface area for transfer of heat from the outside of the container to the interior. The ridges also allow adjustment in the height104and therefore total volume of the container105. Pushing down on the handle106causes the ridges to be compressed together and lowers the height104of the container105. The cooling system further includes a cap102, typically a plastic screw cap that has an opening through which a display103can be seen. The display showing the measured value for the sensor attached to the display as seen in later figures. In a preferred embodiment the display103shows the temperature of the sensor probe. The container is filled with a solution that is to be frozen. The solution is typically that known in the art to be used in refrigerator ice packs. The solution contains either organics, or, inorganic salts, or, both, whose concentration is varied to adjust the freezing point of the solution. In a preferred embodiment the sensor and/or the display are chosen to be used with the particular selected solution, and, include indicia that indicate that the solution has reached a pre-selected value where the contents of the cooling package will be completely frozen, and, the cooling package has attained its optimum cooling capacity. The display further includes indicia that indicate a depletion of the cooling capacity during use such that the cooling package may need to be refrozen to ensure continued cooling and an indicia that indicates the cooling package is fully warmed to ambient and the food stored in association with the cooling package might be unsafe.

FIG. 2shows a side cross-sectional view of the cooling package100. The sensor probe201is seen to extend into the interior of the container105. In the preferred embodiment the sensor probe is a temperature measuring device where the display103shows the temperature within the container105at the location of the distal end206of the probe. The distal end206of the probe is located at a selected distance205such that the distal end of the senor probe201is at a distance205from the top of the container. The distance205can be adjusted by selecting a sensor probe having a chosen length and adjusting the overall height of the container by pressing or raising he handle of the container to adjust the height of the container up or down in the direction104. In a preferred embodiment the height205is selected such that the distal end205of the sensor probe is located within the container105at the point known to freeze last. Such that the temperature at the location of the distal end206of the sensor probe is therefore an indicator that the solution within the container105is fully frozen and the cooling package is at its maximum cooling capacity. The sensor includes the probe201, a sensor body202and a display103. The sensor body includes either mechanical, thermomechanical, electronic components or other fluid or chemical components that control the display103to show the measured conditions at the probe tip206. In a preferred embodiment the sensor body includes a thermomechanical linkage. The cooling package further includes a gasket203that fits against surfaces of the cap102and a threaded spigot204on the container105to create a water tight seal of the sensor and sensor probe to the container105.

FIG. 3shows a top view of the cooling package100. The display103is mounted to the top of the sensor probe and in a preferred embodiment held in place by the screw cap102. The display is visible through the cap, as shown, and includes an indicator301, here shown as a pointing arrow, and indicia302that are indicative of the condition, typically temperature, at the tip of the probe as shown inFIG. 2. Details of the display and indicia are shown inFIG. 7.

FIGS. 4A and 4Bshow exploded views of the sensor, the cap, and, the seal. The sensor assembly400includes a sensor probe201, attached to a sensor body202, the sensor body including a display103, a screw cap102, and, a seal203, shaped to fit to the bottom of the sensor body202and seal against the interior of the cap102, and, against a threaded port or spigot (item204inFIG. 2) on the cooling package container. The display includes, in the preferred embodiment, indicia302, and, an indicator, here, a needle indicator301. In a preferred embodiment the sensor is a temperature sensor and alignment of the needle indicator with the indicia are indicative of the temperature at the distal end206of the sensor probe. In a preferred embodiment, the indicia302are selected on the basis of the freezing point of the solution contained within the cooling device container, and, indicate: 1. When the cooling device is fully frozen and ready for use, 2. when the cooling device is warming above the freezing point of the solution within the container and is losing cooling capacity, and, 3. When the temperature of the device is too high and food spoilage is a risk. The sensor assembly further includes a screw cap102that includes a hole401in its top surface for viewing the display103.FIGS. 5, 6A and 6Bshows details of the fitting of the sensor assembly within the cylindrical port204that is formed in the top of the cooling package container105(seeFIG. 1). The sealing gasket203is comprised of a generally cup shaped body made of a compressible rubber-like material that includes a plurality of sealing surfaces. The top rim of the cup includes a ridge501having a top surface502that seals against the inside surface of the cap102and a bottom surface503that seals against the top surface of the threaded spigot204when the cap102is screwed onto the spigot204. The sealing gasket203further includes an inside vertical surface504that seals against the outer vertical surface508of the sensor probe body202and a horizontal surface505that seals against the bottom surface509of the sensor probe body202. The sealing gasket203further includes a hole507centered in the bottom of the sealing gasket and sized to seal around the sensor probe201as it extends into the inside of the cooling device container.

FIG. 7shows details of a preferred embodiment of the display103. The display includes and indicator301that points to indicia302on the face indicating the measured state of at the distal end of the sensor probe discussed earlier. In the preferred embodiment the sensor probe is a temperature probe and the indicia, here labeled generically A-E, are temperatures at which the solution within the cooling package are:

A—solution is below the freezing point,

B—solution is at freezing point,

C—solution is above the freezing point and cooling package is losing cooling capacity,

D—solution is above freezing point and at the boundary of safe food storage, and,

E—solution is too warm to safely store food products, spoilage may occur.

The display is further divided into zones701-703, Where the first zone701indicates the cooling package is ready to use, the second zone702indicates the cooling package is warming as would be observed in use, but still providing sufficient cooling to prevent rapid spoilage and a third zone703where the cooling package is depleted and should either be re-frozen or replaced with a freshly frozen cooling package. The position of the indicia and the range of the indicator needle301are selected on the basis of the particular solution being used within the cooling package. The display is customized for the particular solution. Being used within the cooling package. In a preferred embodiment the cooling package includes a selection of pre-measured mixes to be used within the cooling package and for each of the pre-measured mixes a sensor probe customized with a display face103including indicia302, and, zones701-703, mechanics to move the indicator needle based upon the range of operating temperatures of the cooling package with the particular selected pre-measured mix. In one embodiment at least two pre-measured mixes are available called A and B and the indicia A would indicate when pre-mix A is ready for use and indicia B would indicate when premix B is ready for use. Similarly, the remaining indicia are an indication of the state of the cooling package relevant to one mix or the other. In one embodiment the highest temperature indicating indicia, here labeled E indicates the cooling package has reached a temperature where there is significant risk of food spoilage. In a preferred embodiment indicia E indicates the food cooling package is above 40° F.

FIGS. 8A and 8Bshow two methods of using a cooling package system that includes an accordion container105having, as already described, a temperature probe including a display103. The display is as described inFIG. 7. The height104, and therefore the volume, of the accordion container105is adjustable by pushing down or pulling up on the handle106. The cooling package system further includes a plurality of additive mixes802,803, here two are shown. The cooling package is prepared for use by selecting an additive mix, either A802or B803. The mix is selected on the basis of a desired operating temperature and/or a cooling capacity. The mix is combined with a prescribed volume of water (804for mix A and805for mix B) such that the combined volume of water and additive mix when fully dissolve, will produce a solution that has a pre-selected freezing point. The height104and therefore the volume of the cooling package container105is adjusted to expel air from the container with the cap102loosened or removed and then the cap is replaced to produce a sealed solution. The mix of additive A802with the prescribed amount of water804when fully frozen will be ready to use when the indicator on the display103is pointing to the indicia A and the mix of additive B with the prescribed amount of water805will, when frozen, be ready to use when the indicator on the display103is pointing to the indicia B. The preparations A or B so produced will be partially depleted as to cooling capacity when the indicator points to indicia C and D respectively. And, either solution preparation A or B is fully depleted when the indicator points to indicia E. The particular wording of the indicia on the display may be any that indicates 1. When the cooling package is ready for use, 2. When the cooling package is partially depleted and 3. When the cooling package is fully depleted at food spoilage may occur.

In another embodiment shown inFIG. 8B, the cooling package806includes a pre-measured amount of additive807added to the container105with a prescribed amount of water808,809to be added by the user. The amounts of water include options of a larger amount808or a smaller amount809. Once the water is added, the height104, and, therefore volume of the container105is adjusted such that the water level is at the height of the cap102and the cap, with sensor probe, is screwed to the container105. In the preferred embodiment the additive and the larger amount of water produces a first cooling package810that uses 7 quarts of water, has a first freezing point of −5° C. and weighs 16 lbs and the same cooling package materials, using 6 quarts of water produces a second cooling package811that has a second freezing point of −6° C. and weighs 13.5 lbs. The combination of a container105with an adjustable104size and adjustable amounts of additive and water enables a cooling package that can be customized for applications over a wide range of operating temperatures and sizes. The temperature probe indicates when any of the particular selected operating temperatures are ready to use, partially depleted and unsafe for the selected use.

FIG. 9shows an embodiment of a sensor probe900that further includes electronics that can process a signal from a sensor905where the sensor is any selected from a thermal sensor, a pH sensor, a conductivity sensor. The sensor body902in the example is the same shape as those previously described (item202,FIG. 2) and uses the same sealing gasket, again as already described. The Sensor is included in a sensor probe901and is connected to an analog to digital converter902, a microprocessor903, a user interface904, a display906, and, a battery907to power the electronics. In one embodiment the display906is the same display as previously described including a needle indicator and indicia. In this case the display shows, however, a measure from the sensor905that is indicative of spoilage of a food product into which the sensor through the sensor probe is inserted. In one embodiment the sensor905is a pH probe and the electronics receive a voltage signal from the pH sensor that is processed to indicate the pH of the food product and the pH is indicative of the safety of the food product for consumption. In one embodiment the food product is milk and the pH probe indicates the relative concentration of lactic acid in the milk, excess lactic acid indicative of spoilage. Spoilage is indicated as the pH of the milk decreases from a normal range of 6.5 to 6.8 to below 6.5, such as a pH of 5. The indicia in the display are selected to show good, drinkable milk, at pH's above approximately 6.5 and spoiled milk at pH's below approximately 6.0, and milk that is well on its way to spoiled with measured pH between those points. In another embodiment the sensor is an electrical conductivity sensor and as the milk spoils, the added lactic acid causes an increase in the conductivity of the solution. The electronics are programmed to display a warning to the user that the milk product within the container is spoiled when the conductivity exceeds a pre-selected level.

In another embodiment the probe is a temperature probe and the electronics through use of a thermal probe acquire time and temperature data. It is known in the art that food spoilage is a function not just of an elevated temperature but also how long the food has been stored at an elevated (typically above 40° F., but dependent upon the type of food product). In one embodiment the sensor electronics sum up the total amount of time that a food product is above a pre-selected temperature. A cumulative time for food held above 40° F. is indicative of spoilage and the display includes an indicator and indicia that are read to indicate the food has been, cumulatively, too warm for too long.

In another embodiment the user interface904is a button that, when pressed, causes a measurement to be made and the result displayed on the display906.

FIG. 10shows an image of the invented probe900ofFIG. 9, attached directly to a food package1001through a screw top1002and threaded spigot1003. In the embodiment shown the probe includes a user interface904and a display906. In one embodiment the display includes a graphics display. In another embodiment the display include an LED display where if the food product is ok the LED is green when the user interface button is pushed and if the food product is spoiled the display will show red and optionally flash on and off. In one embodiment the probe905is a pH sensor and good and bad are determined by the pH of the food product in the container. The case of detecting food spoilage using pH and where the food product is milk was discussed earlier. In another embodiment the sensor probe905includes an electrical conductivity sensor. In another embodiment the sensor is a temperature probe. In another embodiment the sensor includes any of a temperature probe, an electrical conductivity probe and a pH probe and spoilage is indicated if any of the temperature, pH and electrical conductivity is outside of pre-selected ranges for temperature, pH and electrical conductivity. In another embodiment the sensor is a temperature probe and the sensor includes a computing device that determines spoilage on the basis of the integrated time the product in the container is above a pre-selected temperature. In another embodiment spoilage is defined as freezing of the product and the product is determined to be spoiled if it has been frozen and thawed more than a pre-selected number of freeze-thaw cycles.

SUMMARY

A cooling package that includes a sensor that provides a signal to the user to indicate that the cooling package is ready for use and when the cooling package is depleted is described. The sensor and sensor display are selected on the basis of the freezing point of the contained solution. The freezing point of the solution is adjustable through use of organic or inorganic additives. The sensor can further be used by placement directly in contact with a food product and through measurement of temperature, pH or electrical conductivity a signal to the user through the built in display warns of food spoilage if the temperature, cumulative time above a pre-selected temperature, pH or electrical conductivity exceed a pre-selected limit.