Patent Application
20080285622
The present invention generally relates to devices used to sense temperature or other parameters (e.g., humidity, weight, etc.) in the operation of appliances. More particularly, the invention relates to a magnetic attachment to metal, ceramic or glass cookware, for example, useful in controlling the heating of cookware in closed-loop operations of appliances.
Various methods are known for heating cookware and food containers. As one example, radio-frequency identification (RFID) tagging systems have been used to activate and control magnetic induction heating systems for use in heating foods and associated food containers and cookware. Use of such systems allows objects not physically connected to a magnetic induction heater to be heated and temperature-regulated using RFID technology. In such systems, an RFID tag having a temperature sensor may be mounted within an item to be heated, such as cookware, while the magnetic induction heater may include an RFID reader. When the tagged object comes within the reading field of the RFID reader, the tag may be used to transmit information such as the class of object being heated, so that the heater control circuitry may use the information to commence an appropriate heating cycle for heating and temperature-regulating the object. Various such systems are available, including those disclosed in U.S. Pat. No. 6,025,725 to Gershenfeld et al., and U.S. Pat. Nos. 6,320,169 and 6,953,919 to Clothier, the entire disclosures of each of these three patents hereby being incorporated by reference herein. Use of this technology enables relatively precise heating and temperature regulation.
Other non-contact/indirect, remote control methods are known or may be devised. As non-limiting examples, remote controller devices used with televisions typically operate based on optical (infrared) communication. Non-contact modes of communication other than RFID may be used, likewise, for measuring the temperature of cookware and food containers, such as those involving communication via optical means, ultrasound, infrared, or other communication modes.
It would be advantageous to devise a way to attach temperature-sensing tags to cookware in a manner that enables the tag to be easily removed from the cookware, as well as to be attached to cookware of various sizes, so that the tag may be read (using RFID or other communication modes) by a reader associated with a heating device, such as but not limited to a magnetic induction heating device. The tag must be resistant to and useable in the presence of fairly high temperatures, i.e., those associated with conventional cooking temperatures for foods. The tag should also preferably be rugged and durable, cleanable, and resistant to deterioration when subjected to the presence of food or cleaning materials and methods.
Accordingly, there is a need to mount heat-resistant tagging mechanisms to cookware of various shapes and sizes, in a manner that enables the tagging mechanism to be easily removed from the metal cookware and/or food container, to enable control over cooking and/or warming applications of food contained therein.
The following terms are used in the claims of the patent as filed and are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language.
“Closed-loop” means an operation influenced or controlled by the effect it has on a measured parameter. For example, a temperature sensor may be used to control heating in a closed-loop operation.
“Cookware” means cooking, serving or delivery containers for food, including but not limited to dishes, pots, trays including buffet trays and warming trays, etc.
“Food” means any item or material which may be normally ingested by humans, including solid or liquid matter.
“Indirect heater” or “indirect heating” or “indirect heating system” means a heater or method of heating, or system involving such heating, respectively, in which food contained by an item of cookware or other cooking, serving or delivery food container, is heated through conduction of heat from the cookware or container to the food.
“Reader” means a device capable of receiving information from a tag relevant to the heating of cookware of other cooking-, serving-, or delivery-related food containers, and of transmitting this information to heating controls associated with an indirect heater.
“RFID technology” means a tagging system including but not limited to a tag having information regarding an object, such as its temperature, humidity, volume or weight, and a reader in communication with the tag and with an appliance such as an induction heater separated by some distance from the tag.
“Tag” means a device possessing information relevant to the heating of cookware or other cooking-, serving- or delivery-related food containers, that is capable of transmitting sensor information such as but not limited to temperature, humidity, volume or weight to a reader associated with heating controls of an indirect heater, which communication may occur through the mode of RFID, optical, ultrasound, or other modes.
The objects mentioned above, as well as other objects, are solved by the present invention, which overcomes disadvantages of prior tagging mechanisms and systems used with heating devices for cooking and/or warming applications, while providing new advantages not previously obtainable with such tagging mechanisms and systems.
In a preferred embodiment, a detachable apparatus is provided for measuring the temperature of cookware, providing for closed-loop heating control. Using this detachable apparatus, an item of cookware may be heated in the following manner. A cookware item has a tag associated with it. The tag is capable of communication with a reader; the reader is in communication with heating controls of a heater, such as but not limited to a magnetic induction heater. A magnetic detachable coupler carrying the tag is provided. The coupler permits removable attachment of the coupler to the cookware item.
In one embodiment, RFID tags and readers may be employed. In a preferred embodiment, the magnetic coupler includes a housing in which the tag is located, and a tongue portion with a temperature sensor which may be in electrical communication with the tag. Preferably, the tongue portion is in abutting contact with the cookware item when the magnetic coupler is magnetically coupled to the cookware item. When attached to the bottom of cookware, the tongue portion preferably is relatively thin, and has a thickness of less than about 0.100 inches, for example, so that the cookware does not rock during heating. The tongue portion may be made of Kapton or polyamide, and may be made of multiple layers of such material, with wires located between two layers, for example, in the manner that printed circuit boards are fabricated. The tag may be hermetically sealed from the environment of the cookware item, using a gluing or potting compound, for example. The housing may be generally triangularly-shaped in cross-section, or may have other cross-sectional shapes, preferably provided the housing with a length which provides that the tag is in receptive communication with an antenna, such as an antenna which may be located beneath the surface of an oven range.
The invention has advantage in applications other than heating cookware using magnetic induction heating controls. For example, the tag and the reader may communicate optically, or using ultrasound waves. Also, parameters other than temperature may be sensed and controlled, such as humidity, weight, etc.
In a preferred embodiment, the detachable magnetic coupler includes a housing and a first endcap removably attached to the housing, and one or more magnets may be located within the endcap. The first endcap may be removably attachable to the housing, and shaped, such as a curvilinear shape, to facilitate attachment to a first (e.g., curved) cookware item. The first endcap may be removed, and a second endcap, also removably attachable to the housing, and having a different shape than the first endcap, may be used to facilitate attachment of the magnetic coupler to a second cookware item having a different size than the first cookware item. Preferably, the first and second endcaps have an engaging surface which matingly abuts an exterior, engaging surface of the correspondingly-sized cookware item.
In another embodiment, double-sided adhesive means may be employed for attachment to the tagging mechanism, permitting the tagging mechanism to be attached to a non-metal cookware item.
In another embodiment, a system may be employed using a detachable apparatus for measuring temperature within cookware, providing for closed-loop heating control. In such a system, an item of cookware to be heated is provided with a tag. A heater is also provided, having heating controls in communication with a reader; the reader is capable of receiving information from the tag. A magnetic detachable coupler carries the tag. The coupler permits removable attachment of the coupler to the cookware item. Using this system, parameters other than temperature may be sensed and controlled by a control apparatus which variably, quantitatively controls the parameter to be measured or sensed. Such parameters may include, but are not limited to, humidity, weight, etc. The control apparatus may be a humidifier, a scale, an optical and/or infrared measuring and controlling instrument, etc. The control apparatus may be in communication with a reader capable of receiving information from the tag. A magnetic detachable coupler may carry the tag. The coupler permits removable attachment of the coupler to the control apparatus.
In yet another embodiment, a method is provided for attaching a tagging mechanism to an item of cookware to be heated by a heater. The heater has control circuitry in communication with a reader capable of receiving heat-related information from a tagging mechanism. Using this method, a tagging mechanism is magnetically coupled, in a selectively detachable manner, to the cookware item. The shape of the tagging mechanism may be transformed to enable the tagging mechanism to fit cookware items having different shapes and sizes. The tagging mechanism may include a housing and first endcap abutting the cookware item, and the transforming step may involve replacing the first endcap with a second endcap having a different shape. Magnetic induction heating, for example, may be employed to heat the cookware using information provided by the tagging mechanism that has been communicated to the reader, and from the reader to the heater control circuitry.
The novel features which are characteristic of the invention are set forth in the appended claims. The invention itself, however, together with further objects and attendant advantages thereof, will be best understood by reference to the following description taken in connection with the accompanying drawings, in which:
a is a partial side, cross-sectional view of the tongue portion and a temperature sensor;
The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention.
Set forth below is a description of what are believed to be the preferred embodiments and/or best examples of the invention claimed. Future and present alternatives and modifications to this preferred embodiment are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure, or in result are intended to be covered by the claims of this patent.
Referring to
Referring to
Referring now to
Magnets 33, which are preferably powerful magnets, such as rare earth magnets (e.g., ⅜″ diameter, ¼″ long), may be glued into cap 32, and cap 32 may then be glued into housing 31. After the adhesives have dried, the housing may be back-filled through fill hole 45 with foam (e.g., Reltek B481 potting compound) to prevent water or other fluids from filling the cavity should the tagging mechanism undergo a wash cycle. A label 46 may be added, covering the fill hole.
RFID tag 42 may now be programmed with information an RFID reader may use for heating controls of appropriately-sized cookware, for example, prior to shipping of the final tagging mechanism.
Housing 31 and endcap 32 may be made of plastic, such as cast urethane, polyethylene, nylon, ABS (acrylonitrile butadiene styrene), etc. Referring to
Preferably, tagging mechanism 30 consists of a modular mechanical assembly which may be easily changed to fit (e.g.) cookware of various shapes and sizes. In the preferred embodiment shown in
Referring now to
Referring now to
Referring now to
Tongue 34 is preferably relatively thin, such as less than about 0.100″ thick, and more preferably about 0.060″ thick, so that when the tongue is placed below a cookware item, such as a cooking pot, the pot will not rock due to the thickness of the tongue beneath it.
If a food container or item of cookware is not metal-based, it would also be advantageous to provide a mechanism for attaching a tag in this event. For this purpose, double-face adhesive tape, such as 3M tape No. 468, may be attached to a non-metal cookware item such as glass or ceramic cookware, for example, while the other side of the tape may be adhered to the tagging mechanism. The 3M tape identified here is one preferred adhesive as it is temperature-resistant and may also be used in a food environment.
The above description is not intended to limit the meaning of the words used in the following claims that define the invention. For example, while preferred embodiments involving power induction principles applied to movable glass have been described above, persons of ordinary skill in the art will understand that a variety of other designs still falling within the scope of the following claims may be envisioned and used. It is contemplated that future modifications in structure, function or result will exist that are not substantial changes and that all such insubstantial changes in what is claimed are intended to be covered by the claims.
