US4115678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave oven
Assignee: Hitachi Global Life Solutions Inc
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Filing: 1977-02-25
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Granted: 1978-09-19
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Expires: 1997-02-25
Abstract
Abstract A microwave oven in which the amount of ventilation for a heating chamber is changed dependent upon whether the heating time is controlled automatically or whether the heating time is controlled by manually setting a timer or a like device, whereby the deposition of dew on the wall of the heating chamber and the obscuring of a viewing panel are prevented.
Inventors
- 👤 Hajime Tachikawa
- 👤 Kenji Satoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:57
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/642; H05B6/6408; H05B6/6411; H05B6/6447; H05B6/645
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
235 words
A microwave oven comprising: a casing constituting a heating chamber for accommodating an object to be heated; a high-frequency energy generator operative to generate high-frequency energy and feeding it to said heating chamber; means for ventilation of air in said heating chamber, said ventilation means including a ventilation path constituted in part by the space of said heating chamber, said high-frequency energy generator being disposed on a part of said ventilation path which is outside of said heating chamber; first heating time control means for automatically controlling the heating time for an object to be heated, said first heating time control means including temperature sensor means for sensing at least one of temperatures of the air within said heating chamber and of the air drawn out of said heating chamber and means for controlling said high-frequency energy generator to change the amount of supply of the high-frequency energy from said generator when the temperature sensed by said temperature sensor means reaches a predetermined value; second heating time control means for manually controlling the heating time for an object to be heated; means for selectively actuating said first and second heating time control means to change the heating time control mode between an automatic and a manual control mode; and means for varying the amount of ventilation achieved by said ventilation means in accordance with the heating time control mode selected by said selectively actuating means.
Claim 2
Dependent Claim
235 words
A microwave oven comprising: a casing constituting a heating chamber for accommodating an object to be heated; a high-frequency energy generator operative to generate high-frequency energy and feeding it to said heating chamber; means for ventilation of air in said heating chamber, said ventilation means including a ventilation path constituted in part by the space of said heating chamber, said high-frequency energy generator being disposed on a part of said ventilation path which is outside of said heating chamber; first heating time control means for automatically controlling the heating time for an object to be heated, said first heating time control means including temperature sensor means for sensing at least one of temperatures of the air within said heating chamber and of the air drawn out of said heating chamber and means for controlling said high-frequency energy generator to change the amount of supply of the high-frequency energy from said generator when the temperature sensed by said temperature sensor means reaches a predetermined value; second heating time control means for manually controlling the heating time for an object to be heated; means for selectively actuating said first and second heating time control means to change the heating time control mode between an automatic and a manual control mode; and means for varying the amount of ventilation achieved by said ventilation means in accordance with the heating time control mode selected by said selectively actuating means.
Claim 3
Dependent Claim
41 words
A microwave oven according to claim 1, wherein said ventilation amount viewing means controls the amount of ventilation to a smaller value when the first heating time control means is actuated than when the second heating time control means is actuated.
Claim 4
Dependent Claim
28 words
A microwave oven according to claim 2, wherein said ventilation means includes an electrical-motor-driven fan disposed on said ventilation path for controlling air flow through said heating chamber.
Claim 5
Dependent Claim
23 words
A microwave oven according to claim 3, wherein said ventilation amount varying means includes means for controlling the rotational speed of said fan.
Claim 6
Dependent Claim
30 words
A microwave oven according to claim 4, wherein said fan rotational speed control means includes means for controlling the input frequency to an electrical motor adapted to drive said fan.
Claim 7
Dependent Claim
30 words
A microwave oven according to claim 4, wherein said fan rotational speed control means includes means for controlling the input voltage to an electrical motor adapted to drive said fan.
Claim 8
Dependent Claim
32 words
A microwave oven according to claim 4, wherein said fan rotational speed control means includes a speed change clutch which couples said fan with an electrical motor adapted to drive said fan.
Claim 9
Dependent Claim
46 words
A microwave oven according to claim 2, wherein said ventilation amount varying means includes a shutter disposed on a part of said ventilation path, said shutter being operable to be opened and closed for changing the cross sectional area of said ventilation path at said part.
Claim 10
Dependent Claim
46 words
A microwave oven according to claim 3, wherein said ventilation amount varying means includes a shutter disposed on a part of said ventilation path, said shutter being operable to be opened and closed for changing the cross sectional area of said ventilation path at said part.
Claim 11
Dependent Claim
35 words
A microwave oven according to claim 1, wherein said ventilation amount varying means controls the amount of ventilation to prevent dew formation on walls of said heating chamber at least during said manual control mode.
Claim 12
Dependent Claim
32 words
A microwave oven according to claim 1, wherein said ventilation amount varying means controls the velocity of air flow through said heating chamber in accordance with the heating time control mode selected.
Claim 13
Dependent Claim
36 words
A microwave oven according to claim 1, wherein said ventilation amount varying means controls the cross-sectional area of said ventilation path along at least one part thereof in accordance with the heating time control mode selected.
References Cited (Backward Citations)
US3185809A
Cited
US3281568A
Cited
US3407279A
Cited
US3569656A
Cited
US3716687A
Cited
US4028520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |