Electric heating – Heating devices – Combined with container – enclosure – or support for material...
Reexamination Certificate
2003-05-28
2004-10-19
Paik, Sang (Department: 3742)
Electric heating
Heating devices
Combined with container, enclosure, or support for material...
C219S446100
Reexamination Certificate
active
06806444
ABSTRACT:
FIELD OF THE INVENTION
The field of this invention is heat warning safety devices, and more particularly, such devices for warning individuals that a surface is dangerously hot.
BACKGROUND OF THE INVENTION AND DISCUSSION OF THE PRIOR ART
With respect to stoves and related appliances, various kinds of stoves—electric, gas, smooth cooktop stoves which use glass or metal tops—and toaster ovens are well known to be used for heating food. In addition, “mobile stove-type appliances” such as hot plates and warming trays are well known to be used for heating food. Each of these kinds of stoves and “mobile stove-type appliances” present a safety problem since the heating elements of the stove are hot during the cooking process and remain hot well afterwards. During the cooking process, the safety problem caused by touching the heating element is mitigated somewhat by visual inspection of the stove. With a gas, electric or smooth top stove, for example, the presence of a pot or other utensil on top of the stove might alert someone to the fact that the stove appears to be in use for cooking and therefore too hot to touch. Even the presence of a pot or other utensil is not a reliable clue, however, since people tend to leave tea kettles on their stove perpetually. When the cooking process has ended, however, it is generally impossible to detect that the heating elements of the stove remains hot and would burn the skin of anyone who touched them. There is no visual or other clue that the stove is hot.
To some degree, adults have developed an inherent caution when approaching stoves because of their experience and knowledge in dealing with such safety problems. This inherent caution, however, does not obviate the need for a device that warns the adult when touching the stove would be dangerous. Moreover, children, and particularly young children, usually have not developed such a watchfulness and there has long been a need for a device that can prevent burn accidents to children who may inadvertently touch a stove that is hot, especially when the stove remains hot well after the cooking process has ended.
Furthermore, the reduction in the size of modem kitchens has led the occupants of modern apartments to make use of the stove as an extension of the counter top adjacent the stove as a resting places for large items that have been carried into the kitchen area. An example of such items is heavy bags of groceries brought into the kitchen. There is an urge to set the bags down on the nearest flat surfaces, which may be the top of a stove adjacent a counter top. This is particularly true for those stoves that are smooth on top, such as smooth cooktops. In general, the top surfaces of modern kitchen stoves are increasingly flat, especially the top surfaces of smooth cooktops. These factors have only increased the danger to adults when the top surfaces of stoves are used as a resting place for packages, such as groceries brought into the kitchen.
Smooth cooktop stoves presently are also dangerous if touched on their top surface when they are still hot, even after use. These smooth cooktop stoves, or “smoothtops” as they are sometimes called, utilize as the heating element separate areas on the top surface of the stove (at the same location that gas stove would have burners) which are made of glass. Under each area, usually circular, is a strong light source, such as a halogen lights. The light source projects the light upward to the surface area of the smoothtop's heating element—the glass area on the top surface of the stove. Since the glass area is coated on its bottom with a dark coating, when the light strikes it, the heat from the strong light is absorbed by the glass area and these glass surfaces form each heating element of the stove.
Another variation of the smooth cooktop is the use of a “ribbon heating element” where the smooth glass surface is heated by a coiled electric circuit called a “ribbon element” just underneath it instead of by a halogen light source. The heat is transmitted directly upward so that only the heat element itself gets hot and the rest of the cooktop surface remains cool. In some cases, the ribbon heating element also has another feature whereby the heating element is made of two concentric circles so that the option exists of two sizes of the heating element to match the two different sizes of the pans that need to be heated. This new technology does not solve the problem of warning adults and children that the heating element should not be touched when the cooking process has ended. If anything, it generates the additional hazard that someone can be lulled into touching the heating element after thinking the heating element is cool since the surface right adjacent to it is indeed cool.
Some of these problems have been addressed in Applicant's U.S. Pat. No. 6,104,007 and in pending patent applications, through use of heat warning safety devices that includes a warning symbol that appears directly on the heating element of a stove and by using thermochromic compositions such as for inserts or overlays. Thermochromic materials include liquid crystal (whether cholesteric or chiral nematic) compositions that change color when passing through a given temperature range, and such compositions are now familiar to consumers from their frequent use in inexpensive items, like temperature indicating refrigerator magnets or stick-on aquarium thermometers.
Presently, in order to address the danger of touching a hot “smoothtop” stove, such stoves generally have several light indicators, each one corresponding to each heating element, all located in small one rectangular area on the surface of the cooktop. The light indicators remain lit for a certain length of time after the stove's heating element is turned off in order to deter someone from touching the heating element when it is still hot, although “off”. The light indicators themselves consist of a “dot” or red LED or other indicator, each dot corresponding to a different heating element. Unfortunately, this attempt to address the danger of touching a hot stove of the smooth cooktop variety is insufficient as a warning system (putting aside the fact that the light indicators as an indicator of residual heat after the heating element is turned off are presently designed only for the smooth cooktop variety stoves to begin with and not for gas and electric coil stoves).
A quick glance at the group of light indicators would not be sufficient to warn the average adult, no less children or the elderly, that a particular heating element is too hot. This is because the group of light indicators do not immediately tell someone which heating elements correspond to which light indicators. At a minimum, several seconds of concentration are needed in order to determine from the light indicators that are “on”, which heating elements are too hot to touch. Many adults, and certainly most children, cannot afford those seconds of deduction since their desire to touch the stove is immediate. In addition, an adult carrying groceries into the kitchen and looking for a counter top to place them on or a child running into and playing in the kitchen are even less likely than the average adult or child to take the time to engage in a several second thinking process. Accordingly, the child or the adult will be inadequately warned about the danger of being burned. With this in mind, it is no surprise that a 1997 industrial design exhibit at the Cooper Hewitt (Smithsonian) in New York demonstrated that over 69% of adults can not match the control knob with its corresponding burner (i.e. heating element) on a stove.
Furthermore, the prior art heat indicators can be up to three feet away from the heating element to which they correspond. That distance is too far away for a dangerously hot surface. Surely one would not position a warning for an open air shaft three feet away.
Moreover, the use of a single red LED dot to communicate a warning of heat, while it may have been noticeable and effective in the kitchen of the past, is completel
Horowitz Steven
Paik Sang
LandOfFree
Heat warning safety device using fiber optic cables does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Heat warning safety device using fiber optic cables, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat warning safety device using fiber optic cables will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3270455