Stoves and furnaces – Liquid heater – Open-top vessel that may include lid
Reexamination Certificate
2000-12-18
2002-07-23
Yeung, James C. (Department: 3743)
Stoves and furnaces
Liquid heater
Open-top vessel that may include lid
C126S375100, C220S626000, C220S912000, C099S422000
Reexamination Certificate
active
06422233
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to cooking utensils, particularly to utensils that allow efficient heating with either a gas-cooker burner or an induction heating plate.
BACKGROUND
Cooking utensils manufactured with a base having a composite structure are known. The composite structure comprises a layer of aluminum and a layer of stainless steel stamped and set on the base of the recipient.
It is known in the art to make perforations in a stainless steel plate to allow the aluminum, which is a good thermal conductor, to be flush with the surface of the stainless steel, whose electromagnetic properties favor induction heating. Since aluminum has mechanical properties lower than those of steel, the cumulated perforation surface is generally limited to about 15%. An augmentation in the size and/or number of perforations, according to those skilled in the art, would have the effect of weakening the base. In the same way, perforations may result in reptures of the external skin in the stainless steel and, particularly, when the perforations are of an elongated shape and oriented radially.
Thus, it would be advantageous to improve the performance of such utensils which can be used equally well on a gas-cooker and an induction plate, by providing a base with improved thermal conductivity as well as mechanical resistance. More precisely, it would be highly advantageous to provide a utensil with very high thermal conductivity, for optimum use on a gas-cooker which concerns the majority of users, and whose thermal and mechanical specifications are nonetheless very satisfactory for use on induction plates or halogen plates.
SUMMARY OF THE INVENTION
The invention relates to a cooking utensil including a composite base structure including an aluminum insert plate and an external stainless steel plate, the external plate having perforations therethrough, the perforations filled by portions of the insert plate which are flush with an outer surface of the external plate, the external plate having a central zone stamped to form a sunken disc zone without perforations, and wherein the density of the perforations has a maximum value in an intermediary annular band located on the outer surface, the density of the perforations being higher than about 20% and the surface area of a largest perforation therein being less than about 0.8% of the external plate.
REFERENCES:
patent: 2040102 (1936-05-01), Peron
patent: 2526687 (1950-10-01), Reams
patent: 5564590 (1996-10-01), Kim
patent: 5647271 (1997-07-01), Capelle
Ekono Sarl
Schnader Harrison Segal & Lewis LLP
Yeung James C.
LandOfFree
Cooking utensil with a base constituted of a composite... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cooking utensil with a base constituted of a composite..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cooking utensil with a base constituted of a composite... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2859496