GB2028069A

GB2028069A - Combined microwave and gas heated oven

Info

Publication number: GB2028069A
Application number: GB7926197A
Authority: GB
Original assignee: Tokyo Sanyo Electric Co Ltd; Tottori Sanyo Electric Co Ltd; Sanyo Electric Co Ltd
Current assignee: Tokyo Sanyo Electric Co Ltd; Sanyo Electric Co Ltd; Sanyo Consumer Electronics Co Ltd
Priority date: 1978-08-03
Filing date: 1979-07-27
Publication date: 1980-02-27
Also published as: AU4931079A; GB2028069B; JPS5718577Y2; AU536247B2; JPS5526272U

Abstract

A combined microwave and gas heated oven comprises a cooking chamber 1 formed in an outer casing 2, a door 24 with a microwave and heat seal for closing the cooking chamber 1, a high frequency oscillator 16 for supplying microwave energy to the cooking chamber 1, a separate combustion chamber 5 formed in the outer casing 2, a gas burner 10 disposed in the combustion chamber 5 for supplying combustion heat to the cooking chamber 1, a housing chamber 3 communicating with the cooking chamber 1 through an opening 4, a fan 8 disposed in the housing chamber 3 to circulate the air between the cooking chamber 1 and the housing chamber 3, and an exhaust pipe 12 disposed between exhaust ports 13 formed in the outer casing 2 and the cooking chamber 1, for exhausting portions of circulating combustion heat from the chamber 1. Combustion gas is sucked into cooking chamber 1 through ports 7 by the effect of the circulation of gas from chamber 3 to cooking chamber 1 via blow off ports 28 formed at the edges of a plate 25 partitioning chambers 1 and 3. <IMAGE>

Description

SPECIFICATION Combined high frequency electrical energy and gas heated cooking apparatus This invention relates to a combined high frequency electrical energy and gas heated cooking apparatus.

There is known a cooking apparatus in which high frequency electric waves and heat produced by an electric heater are supplied to the cooking chamber.

In such a cooking apparatus, however, a smallcapacity electric heater may only be used because the allowable electric power is small. The heat produced by such electric heater is therefore useful only in putting a scorching mark onto food to be cooked, and is not sufficient to roast the food.

There has therefore been proposed a combined high frequency electrical energy and gas heated cooking apparatus in which heat from the combustion of gas having a large capacity of calory and high frequency electric waves are supplied to the cooking chamber. Such combined cooking apparatus may perform cooking very efficiently by supplying to the cooking chamber heat from combustion of the gas and high frequency electric waves either separately or at the same time. In such a combined high frequency electrical energy and gas cooking apparatus, however, the cooking period of time during which food is roasted by gas combustion heat, has relatively been long as compared with the cooking period of time by high frequency electric waves.

Since the entire cooking period of time is dependant on the cooking period of time by combustion heat, a relatively long cooking period of time has finally been inevitably required.

On the other hand, there has conventionally been known a gas oven in which cooking means by high frequency electric waves are not provided and food is therefore cooked only by gas combustion heat. In such a gas oven, the cooking chamber and the combustion chamber having a gas burner have been formed separately from each other, and heat in the cooking chamber has been circulated by the fan and suitably exhausted. Combustion heat as much as thus exhausted heat has then been induced from the combustion chamber into the cooking chamber, and combustion air as much as thus induced combustion heat has subsequently been supplied to the gas burner. It has however been difficult to induce combustion heat of a sufficient amount from the separated combustion chamber, with the exhaust ports merely disposed in the cooking chamber.

It may be considered to locate the exhaust ports in the passage of the circulating flows caused by the fan. However, in a combined high frequency electrical energy and gas heated cooking apparatus provided with cooking means by high frequency electric waves in addition to the cooking means by gas combustion heat, the high frequency electric wave intercepting arrangement imposes great restrictions on the position of the exhaust ports for combustion heat. Furthermore, such location may raise several problems in connection with circulation of combustion heat in the cooking chamber, exhaust of circulating combustion heat, supply of combustion heat in the combustion chamber to the cooking chamber, supply of combustion air to the gas burner in the combustion chamber, etc.

According to the present invention there is provided a combined high frequency electrical energy and gas heated cooking apparatus comprising; a cooking chamber formed in an outer casing, a door for closing a front opening of said cooking chamber in a heat-tight and electric wave-tight manner; a high frequency oscillator for irradiating high frequency electric waves to the inside of said cooking chamber, a combustion chamber formed in said outer casing independently from said cooking chamber, a gas burner disposed in said combustion chamber and adapted to introduce combustion heat in said combustion chamber to the inside of said cooking chamber for heating the inside of said cooking chamber, a housing chamber communicated with said cooking chamber through an opening, a fan disposed in said housing chamber for circulating air in said cooking chamber between said cooking chamber and said housing chamber, and an exhaust passage formed between exhaust ports in said outer casing and said cooking chamber for exhausting portions of circulating combustion heat in succession.

An embodiment of the present invention provides a combined high frequency electrical energy and gas heated cooking apparatus in which high frequency electric waves and gas combustion heat are supplied to food to be cooked in the cooking chamber either independently or at the same time, thereby to make various kinds of cookings possible, and in which combustion heat is circulated in the cooking chamber by a fan, so that the food to be cooked may efficiently be roasted by combustion heat in a relatively short period of time.

Two embodiments of the present invention will now be described, by way of examples, with refer encetotheaccompanying drawings, in which: Figure 1 is a vertical section view of a first embodiment of a combined high frequency electrical energy and gas heated cooking apparatus according to the present invention; Figure 2 is a front view of the cooking chamber shown in Figure 1; Figure 3 is a horizontal section view of the main portions in Figure 2; Figure 4 is a front view of the inside wall of the cooking chamber shown in Figure 1; Figure 5 is a vertical section view of Figure 4; and Figure 6 is a vertical section view of the main portions of a second embodiment of the present invention.

The description will then be made of a first embod imentofthe combined high frequency electrical energy and gas heated cooking apparatus according to the present invention, with reference to Figures 1 to 5.

A cooking chamber 1 is formed in an outer casing 2. A housing chamber 3 is formed with the rear side of the cooking chamber 1 centrally concaved and is communicated with the cooking chamber 1 through an opening 4. This housing chamber3 is formed as having a long sideways quadrilateral section when viewed from the front side.

A combustion chamber 5 is formed in the outer casing 2 independently from the cooking chamber 1 and is formed underthe cooking chamber 1 and is separated therefrom by the bottom plate 6.

Heat ports 7 are vertically arranged at the both lateral sides of the rear surface of the cooking chamber 1 and are opened projectinglyfrom the rear surface of the cooking chamber 1. These heat ports 7 communicate the combustion chamber 5 with the cooking chamber 1.

A centrifugal fan 8 is rotatably disposed in the housing chamber3 and is driven by a motor 9 disposed outside the housing chamber 3. A gas burner 10 is disposed in the combustion chamber 5. Air intake ports 11 for admitting combustion air to the gas burner 10 are formed in the front wall of the combustion chamber 5. An exhaust pipe 12 projects from the top surface of the housing chamber 3, and the lower end of this exhaust pipe 12 is opened in the area in the housing chamber 3 where high pressure is produced by the fan 8.

Exhaust ports 13 are formed in a plate mounted on the top wall of the outer casing 2. A smoke collecting chamber 14 is formed between the exhaust ports 13 and the upper end of the exhaust pipe 12. An exhaust passage 15 is thus constituted by the exhaust pipe 12, the smoke collecting chamber 14 and the exhaust ports 13.

A high frequency oscillator 16 for supplying high frequency electric waves to the cooking chamber 1 is disposed in the outer casing 2. Above the cooking chamber 1, a high frequency irradiation chamber 17 is formed and partitioned by a heat-resisting electric wave permeable member 18. A waveguide 19 communicates the high frequency oscillator 16 with the high frequency irradiation chamber 17.

A stirrer 20 is rotatably disposed in the high frequency irradiation chamber 17. An impeller 22 is rotatably disposed in a chamber 21 formed above the high frequency irradiation chamber 17 and at the outside of the cooking chamber 1. This impeller 22 is rotatably coupled to the stirrer 20 by a coupling shaft 23. Thus, air from a blower motor (not shown) cools the high frequency oscillator 16 and is then supplied to the rotating drive chamber 21 to rotate the impeller 22 and subsequently the stirrer 20, thereby to stir the high frequency electric waves supplied to the high frequency irradiation chamber 17 from the high frequency oscillator 16.The cooling air supplied to the rotating drive chamber 21 is discharged to the smoke collecting chamber 14, in which such cooling air is mixed with exhaust gas from the exhaust pipe 12, and then discharged from the exhaust ports 13 to the outside of the outer casing 2.

An openable door 24 is disposed for closing the front opening of the cooking chamber 1 in a heattight and electric wave-tight manner.

A partition plate 25 of quadrilateral shape is dis posed at the opening 4 formed between the cooking chamber 1 and the housing chamber 3 and is fixed to the wall of the cooking chamber 1 by screws or the like. A circular suction port 26 is centrally formed in this partition plate 25. Throttle pieces 27 (Figure 3) are formed by forwardly bending the lateral sides of the partition plate 25 and further bending these bent lateral sides in the transverse direction.

Blow-off ports 28 are vertically formed between the side edges of the opening 4 and the lateral sides of the partition plate 25 or the throttle pieces 27.

Horizontal straightening pieces 29 are securely attached to the back surfaces of the throttle pieces 27 of the partition plate 25 at suitable intervals in the vertical direction.

Recessed portions 30 having a quadrilateral section are formed in the lateral sides of the cooking chamber 1. Plate receiving members 31 made of insulator material are fitted in the recessed portions 30 in a slightly projecting manner and are removably hung on pins 32. Plate receiving pieces 33 are formed integrally with the plate receiving member 31 at the upper and lower portions thereof.

Contact pieces 34 made of insulator material are securely fixed to the front surfaces of the throttle pieces 27 of the partition plate 25 in the forwardly projecting manner by suitable means.

The upper and lower contact pieces 34 are located substantially at the same heights of the upper and lower plate receiving pieces 33, respectively.

Horizontal partition pieces 35 having a predetermined depth partition the heat ports 7 into portions having a predetermined vertical length and each of these partition pieces 35 is adapted to intercept high frequency electric waves together with adjacent partition pieces 35 and the lateral sides of the heat ports 7.

Vertical partition pieces 36 are disposed for partitioning the inside of the exhaust pipe 12 into portions having a predetermined length and a predetermined section area, and adapted to intercept high frequency electric waves.

A cover 37 covers the motor 9 for driving the fan 8.

Air inlet ports 38 and air outlet ports 39 are formed in plates disposed at the lower portion and upper portion of the cover 37, respectively. An air inlet 40 is formed in the bottom plate of the outer casing 2. By the blower motor for cooling the high frequency oscillator 16, air entering from the air inlet 40 enters the inside of the cover 37 through the inlet ports 38 of the cover 37, cools the motor 9, then flows out through the outlet ports 39 and is finally discharged from the exhaust ports 13 through the smoke collecting chamber 14.

As thus described hereinbefore, in the combined high frequency electrical energy and gas heated cooking apparatus according to the present invention, high frequency electric waves and combustion heat may be supplied to food to be cooked either independently or at the same time, so that various kinds of cookings can be carried out.

When cooking by combustion heat, the centrifugal fan 8 is rotated by the motor 9, the gases within the cooking chamber 1 are sucked to the housing chamber 3 from the suction port 26 in the partition plate 25, and the gases within the housing chamber 3 are then blown off to the cooking chamber 1 from the blow-off ports 28. Through the adjacent heat ports 7, combustion heat in the combustion chamber 5 is then sucked by the effect of inducement of such blow-off action, and is therefore supplied to the cooking chamber 1. The combustion heat thus supplied to the cooking chamber 1 is sucked to the inside of the housing chamber 3 from the centre portion of the fan 8 through the suction port 26 in the partition plate 25, and then blown off again into the cooking chamber 1 from the blow-off ports 28.

Thereafter, such circulation is repeated.

As thus described herein before, the circulation of combustion heat in the cooking chamber 1 is made at high speeds, so that food to be cooked in the cooking chamber 1 may effectively be roasted in a relatively short period of time.

On the other hand, portions of heat sucked into the housing chamber 3 are discharged to the outside of the outer case 2 from the exhaust ports 13 through the exhaust pipe 12 and the smoke collecting chamber 14. Combustion air as much as thus exhausted heat is then smoothly supplied from the air intake ports 11 to the combustion chamber 5.

When the centrifugal fan 8 is rotated in the housing chamber3 having a quadrilateral section, the blow-off force from each portion of the blow-off ports 28 is not uniform with each other; namely, dependant on the rotation direction of the fan 8, the blow-off force from the upper portion of one blowoff port is stronger than that from the lower portion of said one blow-off port, and the blow-off force from the lower port of the other blow-off port is strongerthan thatfrom the upper portion of said other blow-off port. In view of this, the straightening pieces 29 are attached to the blow-off ports at suitable intervals in this embodiment, and such attachment permits to provide uniform blow-off force from each portion of the blow-off ports 28.Accordingly, even though plates, vessels or racks are placed at the upper and lower stages, food to be cooked on each of such upper and lower plates, vessels or racks may be cooked in a substantially uniform manner.

Furthermore, because the partition pieces 35 are disposed in the heat ports 7 and the partition pieces 36 are disposed in the exhaust pipe 12, high frequency electric waves are intercepted, thereby to prevent the leak of high frequency electric waves.

When plates, vessels or racks 41 are placed on the plate receiving pieces 33, the side edges of the plates, vessels or racks 41 come in contact with the projecting main portions of the plate receiving members 31, so that distances are provided between such plates, vessels or racks and the side walls of the cooking chamber 1. The innermost portions of the plates, vessels or racks 41 come in contact with contact pieces 34, so that distances are provided between such plates, vessels or racks and the partition plate 25. Accordingly, even though the plates, vessels or racks 41 are made of metallic material, such arrangements permit to prevent sparks from taking place between the plates, vessels or racks and the side walls of the cooking chamber 1 when high frequency electric waves are supplied.

A description will now be made of a second embodiment of the present invention with reference to Figure 6.

In this second embodiment, partition pieces 42 corresponding to the partition pieces 35 in the heat ports 7 in the first embodiment, are formed as forwardly inclined, and the front end of each partition pieces 42 is located at the position lowerthanthe rear end of the subsequent lower partition piece 42.

Accordingly, even though an article such as a spoon 43 is inserted by mistake, the partition pieces 43 work as baffle plates. Furthermore, even though many drops of water are produced at the cooking by high frequency electric waves, such drops flow down forwardly on the partition pieces 42, and never flow into the combustion chamber 5, thereby to assure stable combustion of the gas burner 10.

Claims

1. A combined high frequency electrical energy and gas heated cooking apparatus comprising; a cooking chamber formed in an outer casing, a door for closing a front opening of said cooking chamber in a heat-tight and electric wave-tight manner; a high frequency oscillator for irradiating high frequency electric waves to the inside of said cooking chamber, a combustion chamber formed in said outer casing independently from said cooking chamber, a gas burner disposed in said combustion chamber and adapted to introduce combustion heat in said combustion chamber to the inside of said cooking chambey for heating the inside of said cooking chamber, a housing chamber communicated with said cooking chamber th rough an opening, a fan disposed in said housing chamber for circulating air in said cooking chamber between said cooking chamber and said housing chamber, and an exhaust passage formed between exhaust ports in said outer casing and said cooking chamber for exhausting portions of circulating combustion heat in succession.

2. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 1, in which blow-off ports for blowing off circulating combustion heat are formed at lateral sides of said opening between said cooking chamber and said housing chamber, heat ports communicating with said combustion chamber are formed in the wall of the cooking chamber adjacent said blow-off ports, whereby combustion heat in said combustion chamber is introduced from said heat ports into the inside of said cooking chamber under the action of inducement produced by said blow-off ports.

3. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 2, in which high frequency electric wave intercepting means are disposed at said heat ports.

4. Acombined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 1, in which said fan disposed in said housing chamber is a centrifugal fan, and said housing chamber is formed as having a quadrilateral section, and the lower end of said exhaust passage is opened in the area in said housing chamber where high pressure is produced by said fan.

5. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 4, in which high frequency electric waves intercepting means are disposed in said exhaust passage.

6. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 2, in which a partition plate is disposed at said opening between said cooking chamber and said housing chamber and forms said blow-off ports together with the edges of said opening, a suction port for sucking circulating combustion heat to the inside of said housing chamber is centrally formed in said partition plate, and said fan is formed as a centrifugal fan.

7. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 2, in which the section area of said opening between said cooking chamber and said housing chamber is formed small as compared with that of said cooking chamber, and heat ports are formed adjacent said blow-off ports in the wall of said cooking chamber around said opening.

8. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 2, in which air intake ports for sucking combustion air for the gas burner are formed at said combustion chamber, and the outside air is sucked from said air intake ports into said combustion chamber when combustion heat is introduced into said cooking chamber from said combustion chamber through said heat ports in the wall of said cooking chamber.

9. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 3, in which said heat ports formed in the wall of said cooking chamber are partitioned by partition pieces having such dimensions as to intercept high frequency electric waves.

10. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 9, in which said partition pieces are forwardly inclined.

11. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 9, in which a plurality of partition pieces are inclined, and the front end of each partition piece is located at the position lower than the rear end of the subsequent lower partition piece.

12. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 6, in which said blow-off ports are vertically formed at both lateral sides of said opening between said cooking chamber and said housing chamber, and straightening pieces located in said blow-off ports are attached to said partition plate, said straightening pieces permitting circulating combustion heat to be uniformly blown off.

13. A combined high frequency electrical energy and gas heated cooking apparatus as claimed in claim 6, in which forwardly projecting contact pieces made of insulator material are disposed at said partition plate, and plates, vessels or racks come in contact with said stoppers.

14. A combined high frequency electrical energy and gas heated cooking apparatus, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.