Patent US3872276A successfully refreshed from Google Patents.
US3872276A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Including a semiresonant slotted mode stirrer
Assignee: Philips North America LLC
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Filing: 1973-03-09
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Granted: 1975-03-18
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Expires: 1993-03-09
Abstract
Abstract A microwave oven having a field stirrer comprising a circular sheet metal disc having a plurality of radial slots arranged about its periphery. The ends of the segments thus formed are preferably bent at different angles. The slots and segments together form semiresonant elements to which the energy from the microwave generator couples directly and then is reradiated by the rotating disc which acts as a moving virtual energy source. The disc is rotated so that the segments pass by the microwave energy coupling aperture for the oven. The oven combination produces a more uniform microwave energy distribution within the oven cavity and also improves the matching of the microwave generator to the cavity load so that the generator operates in the load region most suitable to the application.
Inventors
- 👤 Richard P Corcoran
- 👤 Alfred E Hirtler
- 👤 Robert F Mittel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:11
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/74
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
154 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, an aperture in a wall of said oven for coupling microwave energy into the oven cavity, means for generating and coupling microwave energy to said aperture, a field stirrer rotatably mounted in the cavity and comprising a thin metal disc having a plurality of radial slots arranged about its periphery to form a plurality of segments with the outer ends of at least some of said segments being bent out of the plane of the disc whereby said slots and segments form semiresonant elements which couple to the R.F. fields in the oven and reradiate the energy in various directions, and means for rotating said disc so that the bent ends pass near said aperture to intercept and reflect the microwave energy entering through the aperture so as to periodically change the mode pattern within the oven cavity.
Claim 2
Dependent Claim
154 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, an aperture in a wall of said oven for coupling microwave energy into the oven cavity, means for generating and coupling microwave energy to said aperture, a field stirrer rotatably mounted in the cavity and comprising a thin metal disc having a plurality of radial slots arranged about its periphery to form a plurality of segments with the outer ends of at least some of said segments being bent out of the plane of the disc whereby said slots and segments form semiresonant elements which couple to the R.F. fields in the oven and reradiate the energy in various directions, and means for rotating said disc so that the bent ends pass near said aperture to intercept and reflect the microwave energy entering through the aperture so as to periodically change the mode pattern within the oven cavity.
Claim 3
Dependent Claim
27 words
A microwave oven as claimed in claim 1 wherein the bent ends of said disc segments are inclined at different angles to the plane of the disc.
Claim 4
Dependent Claim
30 words
A microwave oven as claimed in claim 2 wherein diametrically opposed pairs of end segments of the discs are inclined at the same angle to the plane of the disc.
Claim 5
Dependent Claim
22 words
A mircowaVe oven as claimed in claim 2 wherein the bending angle of the end segments varies progressively about the disc periphery.
Claim 6
Dependent Claim
40 words
A microwave oven as claimed in claim 1 wherein some of the disc end segments are inclined upward from the plane of the disc and other ones of said end segments are inclined downward from the plane of the disc.
Claim 7
Dependent Claim
39 words
A microwave oven as claimed in claim 1 wherein the disc is composed of sheet metal of a thickness which allows it to be easily bent to form different adjustable angles of inclination to the plane of the disc.
Claim 8
Dependent Claim
39 words
A microwave oven as claimed in claim 1 wherein said aperture is located in a side wall of the cavity near the top wall and said stirrer is mounted on a vertical shaft extending from said cavity top wall.
Claim 9
Dependent Claim
36 words
A microwave oven as claimed in claim 1 wherein at least one diametrically opposed pair of end segments are inclined in the same direction to and at the same angle to the plane of the disc.
Claim 10
Dependent Claim
141 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, means for supplying microwave energy into the oven cavity, a field stirrer rotatably mounted within the cavity and comprising a thin metal circular disc having a plurality of radial slots therein to form radial fins arranged about the disc periphery with at least some of the fins inclined in a direction at an angle to the plane of the disc, at least a part of said slots lying in the plane of the disc to function as semiresonant elements, and means for rotating said disc to intercept and interact with the energy supplied to the oven cavity thereby to produce a cyclically repetitive distribution of energy within the cavity which is substantially uniform in the region of the cavity to be occupied by the load.
Claim 11
Dependent Claim
141 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, means for supplying microwave energy into the oven cavity, a field stirrer rotatably mounted within the cavity and comprising a thin metal circular disc having a plurality of radial slots therein to form radial fins arranged about the disc periphery with at least some of the fins inclined in a direction at an angle to the plane of the disc, at least a part of said slots lying in the plane of the disc to function as semiresonant elements, and means for rotating said disc to intercept and interact with the energy supplied to the oven cavity thereby to produce a cyclically repetitive distribution of energy within the cavity which is substantially uniform in the region of the cavity to be occupied by the load.
Claim 12
Dependent Claim
35 words
A microwave oven as claimed in claim 9 wherein said fins are uniformly disposed about the disc periphery and at least some of which are inclined at different angles to the plane of the disc.
Claim 13
Dependent Claim
145 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, means for supplying microwave energy into the oven cavity, a field stirrer rotatably mounted in the cavity and comprising a thin metal circular disc having a plurality of radial slots symmetrically arranged about its periphery to form a plurality of segments with the outer ends of at least some of said segments being bent out of the plane of the disc, said slots being dimensioned so as to form semiresonant elements to which energy from said energy supplying means is coupled directly and then is reradiated to the oven cavity, and means for rotating said disc so as to intercept and interact with the energy from said energy supplying means and the energy within the fields in the oven cavity thereby to improve the energy distribution within said cavity.
Claim 14
Dependent Claim
145 words
A microwave oven comprising a substantially closed metallic cavity adapted to hold an energy absorbing load, means for supplying microwave energy into the oven cavity, a field stirrer rotatably mounted in the cavity and comprising a thin metal circular disc having a plurality of radial slots symmetrically arranged about its periphery to form a plurality of segments with the outer ends of at least some of said segments being bent out of the plane of the disc, said slots being dimensioned so as to form semiresonant elements to which energy from said energy supplying means is coupled directly and then is reradiated to the oven cavity, and means for rotating said disc so as to intercept and interact with the energy from said energy supplying means and the energy within the fields in the oven cavity thereby to improve the energy distribution within said cavity.
Claim 15
Dependent Claim
31 words
A microwave oven as claimed in claim 11 wherein the bent ends of at least some of said disc segments are inclined at different angles to the plane of the disc.
Claim 16
Dependent Claim
36 words
A microwave oven as claimed in claim 12 wherein at least one diametrically opposed pair of end segments are inclined in the same direction to and at the same angle to the plane of the disc.
Claim 17
Dependent Claim
22 words
A microwave oven as claimed in claim 13 wherein the bending angle of the end segments varies progressively about the disc periphery.
Claim 18
Dependent Claim
40 words
A microwave oven as claimed in claim 12 wherein some of the disc end segments are inclined upward from the plane of the disc and other ones of said end segments are inclined downward from the plane of the disc.
Claim 19
Dependent Claim
35 words
A microwave oven as claimed in claim 11 wherein the width of the slots is relatively narrow with respect to the width of the segment area between adjacent slots in the plane of the disc.
References Cited (Backward Citations)
US3626136A
Cited
US3716687A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |