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THERMAL CONVECTION OVEN USING A SYNCHRONOUS MOTOR AND REGULAR POWER INTERRUPTIONS

IP.com Disclosure Number: IPCOM000215820D
Publication Date: 2012-Mar-12
Document File: 4 page(s) / 26K

Publishing Venue

The IP.com Prior Art Database

Abstract

Embodiments of the present invention relate generally to appliances, and more particularly to thermal/convection ovens. An embodiment of the invention has a control mechanism that provides for a regular interruption of power. Additionally, an embodiment of the present invention has a synchronous electrical motor that starts up randomly upon restoration of power, achieving multidirectional air flow.

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THERMAL CONVECTION OVEN USING A SYNCHRONOUS MOTOR AND REGULAR POWER INTERRUPTIONS

BACKGROUND

    Embodiments of the present invention relate generally to appliances, and more particularly to thermal/convection ovens, which comprise a fan for circulating air within the oven.

    In ovens, food is cooked by air in a cooking cavity, which is heated by a heat source. Evenness of cooking is desirable for ovens. Known ovens inject a considerable amount of energy into the cooking cavity in a relatively short time period, such that the cooking cavity temperature may not be timely and precisely controlled. Therefore, at least some known ovens have a cooking cavity temperature variation of more than 20 degrees Fahrenheit, which may lead to uneven cooking and cause variation in browning and a darkening around the edges of baked products.

    Many convection ovens are equipped with fans capable of moving heated air throughout the cooking chamber at various velocities. Normally, such ovens are designed to provide a rapid distribution of heated air over food products which have been placed on pans stacked one above the other. Unfortunately, the distribution of heated air in such ovens is not always as uniform as may be desired. As a result, food products arranged in the cooking cavity and being cooked, e.g., baked, in such an oven may cook at uneven speeds. As a result, particular food products of a single batch can be cooked in an undesirable fashion, for example, to various degrees of doneness and coloring.

    In an effort to improve such cooking results, various oven designs and methods have been proposed or developed. These oven designs and methods include rotating the food product while in the cooking cavity and the use of reversing blowers to change the airflow pattern in or through the cooking cavity.

    One approach directed to solving or reducing at least some of these problems or concerns provides a baking oven which includes a baking chamber and has air channels extending at both sides of the baking chamber as well as over the height of the baking chamber from top to bottom. The air channels are separated from the baking chamber by partition walls having provided therein air flow openings formed by horizontal slots. Heated air is blown in alternating directions

 


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into the baking chamber by means of a blower such as by way of reversing the sense of rotation of the blower.

    Fans in conventional convection ovens are typically powered by electric motors. In order for a fan to blow heated air in alternating directions, the electric motor must be capable of rotating in two directions. Furthermore, in order to achieve the best results, the heated air must be blown in alternating directions for approximately the same amount of time. Therefore, a means for ensuring that the motor rotates in alternate directions for approximately equal amounts of time is necessary. Accordingly, conventional convection oven designs comprise a two dire...