Electric heating – Metal heating – Of cylinders
Patent
1983-01-05
1985-05-14
Envall, Jr., Roy N.
Electric heating
Metal heating
Of cylinders
219 1055R, 34030915, H05B 664
Patent
active
045174318
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a safety means for such heating appliances having a digital control section as electric ovens, microwave ovens, and composite ovens which comprise the two preceding types, wherein the preheating completion time is estimated and reported, and the completion of preparation for cooking is detected by the opening and closing of the door, the time for pushing the start switch is reported, and the completion of preparation is reported upon ascertainment of the completion of a timer setting.
2. Description of the Prior Art
The recent development of semiconductor technology is remarkable, and the incorporation of electronic circuits in control systems is increasing rapidly. With the advent of stored logic type controllers represented by the microcomputer, digitalization of control systems is also increasing rapidly.
In the field of heating appliances also, the wave of such digitalization has changed the arrangement of control systems and the configuration of operating panels to a large extent. New functions which would be impossible to attain with conventional discrete circuits have been added one after another.
However, such digitalization of operating panels and adaptation of heating appliances for multifunction use can complicate the operation of the appliance, resulting in an increasing tendency for the user to experience troubles; user fails to fully utilize the "helpful"functions or erroneously operates the appliance, leading to unsatisfactory heating. Even a failure of part of the circuitry can cause the control system to run away, contrary to the user's intention.
Accordingly, there has been a desire for a heating appliance which will never start heating until the user has set desired data on heating, will report to the user the acceptance of the effective heating data by the control system to thereby make the operation readily understandable, and is capable of preventing the control system from running away even in the event of a failure.
As for an error often found particularly in the composite oven, the user forgets to do the idle heating, which is called preheating, (i.e., heating with no load put in the heating chamber) and consequently fails in cooking or by mistake the idle heating is performed for a cooking mode which forbids it. The number of such errors is increasing.
The manner of operating the heating appliance largely depends on differences in the type of heat source and in the method of heating food.
First, reference will be given to heating appliances equipped with an electric heater or gas burner as a heat source, such as an oven (hot oven) and grill. These heat sources heat food externally. Further, these heating methods can be roughly classified into two types by the heating mechanism, as follows.
One type is oven heating wherein food is baked in a heated atmosphere. This is a heating method wherein food is baked in a high temperature atmosphere with the radiant heat from the heat source being prevented from reaching the food. In this case, it is necessary to sufficiently elevate the temperature in the heating chamber prior to putting food therein. That is, idle heating called preheating must be done. Neglecting this would require a longer heating time or even cause a failure in cooking depending upon the kind of dish.
The other type is grill heating wherein food is baked by the radiant heat from the heat source. This type does not require preheating since heating is carried out by the infrared radiation from the heat source. If preheating is performed by mistake, the interior of the heating chamber will reach a considerably high temperature in a short time , entailing danger. The user will be given a rough estimate of the required heating time for grill heating under conditions not including unnecessary preheating; thus, preheating would result in scorching.
While the foregoing refers to the difference based on the presence or absence of preheating, there is another great difference in operation between oven
REFERENCES:
patent: 3641496 (1972-02-01), Slavin
patent: 4011428 (1977-03-01), Fosnough et al.
patent: 4158759 (1979-06-01), Mason
patent: 4163120 (1979-07-01), Baumwolspiner
patent: 4242554 (1980-12-01), Hurko et al.
patent: 4351999 (1982-09-01), Nagamoto et al.
patent: 4396817 (1983-08-01), Eck et al.
Envall Jr. Roy N.
Lateef M. M.
Matsushita Electric - Industrial Co., Ltd.
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