This invention relates in general to cooking apparatus. More specifically, it relates to a broiler for food products that cooks both sides of the food products simultaneously.
A wide variety of food broilers are known. Most of them, whether as a component of a stove for residential use or a commercial broiler for use in a restaurant, cook the food using either direct fired burners or high temperature radiant elements. Many direct fired units use gas as a fuel. Electrical resistance heating elements are common for radiant heat broiling. A significant advantage of electrical heating elements is that they can be arranged to cook both the upper and lower surfaces of the food simultaneously. This results in a faster cooking time, superior cooking, and avoids the necessity of turning the food while it cooks. Gas-fueled units can also be arranged to cook both sides of the food simultaneously, but in known units the upper and lower gas units are separately fired.
Also known are cooking appliances having an over-fired broiler and a griddle located above the broiler. In such an arrangement waste heat from the radiant heating elements above the food in the broiler is used to heat the griddle above the broiler.
These known arrangements suffer from several disadvantages. One is that they are not fuel efficient because a major portion of the heat of combustion is simply exhausted. Also, many commercial units use excessive amounts of fuel because their burners have manual controls only and may be fired continuously over a work day of about ten hours even though their broilers actually cook food only a total of a few hours of the day. Another disadvantage is that direct fired units (e.g. most gas broilers), produce an uneven heating. Hot spots exist in the broiler which can result in overcooking or burning the food. In large commercial broilers, to control the uniformity of the heat throughout the cook zone requires multiple heating elements, temperature controls for each element, and with some systems, arrangements for circulating or distributing the heat energy. These problems are, of course, accentuated for broilers that cook the upper and lower sides of the food simultaneously. In fossil fuel fired units, another consideration is the level of emissions of toxic gases such as carbon monoxide and nitrogen oxides.
Cooking devices using heat pipes such as pans, ovens, deep fat fryers, griddles, and broilers are described in U.S. Pat. Nos. 3,791,372; 3,853,112, 3,948,244; 3,985,120; and 4,091,801, all of which are commonly assigned with the present application. In general these devices each have an enclosure for a working fluid that is divided into an evaporator zone in communication with a heat source and a condenser zone that transmits the latent heat of condensation of the working fluid to the food. They have certain advantages of heat pipe cooking such as a uniformity of temperature over the cooking surface or surfaces, central heating of one evaporator zone, and associated ecomonies and precision in the control of the cooking temperature. One of these patents, U.S. Pat. No. 3,853,112, describes a heat pipe cooking appliance where the condenser zone is a series of generally parallel "tubes" that each extend between hollow connecting tubes that in turn communicate with the evaporation zone. The food rests on the tubes. This "broiler", however, cooks only one side of the food product at a time.
It is therefore a principal object of this invention to provide a fossil-fuel fired broiler that cooks food products on opposite sides simultaneously with a resulting decrease in cooking time and improved quality of the cooked food.
Another principal object is to provide a broiler with the foregoing advantages that is fuel efficient and characterized by a comparatively low level of toxic gas emissions.
A further object of the invention is to provide a broiler with the foregoing advantages that cooks uniformly throughout a cooking region.
Yet another object of the invention is to provide a broiler that cooks a food product on opposite sides simultaneously while utilizing only one burner and one associated control system.
Another object of the invention is to provide a broiler with the foregoing advantages and whose control system automatically regulates burner firing to minimize fuel use.
Still another object of this invention is to provide a broiler with the foregoing advantages that can produce "sear lines" on the food product characteristic of conventional open flame cooking on a grill.
Another object is to provide a broiler with the foregoing advantages that is relatively easy to clean.
A still further object of the invention is to provide a broiler with the foregoing advantages that facilitates the movement of the food product to and from an optimal cooking location within the broiler.