US3898412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive position interlock concealment shutter
Assignee: United States Department of Health and Human Services
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Filing: 1974-05-21
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Granted: 1975-08-05
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Expires: 1994-05-21
Abstract
Abstract A positive position interlock concealment shutter - for preventing the accidental or intentional actuation of a concealed interlock switch in a microwave oven when its door is in the open position - comprises a moveable metal plate having an aperture therethrough which can be aligned with the conventional aperture in the oven face. The position of the plate and its aperture is controlled by a door guide arm which includes a camming surface. The slope of the cam surface is designed to allow sufficient door movement for the latch pawl or the door pin to clear the shutter aperture during door opening before shutter closing occurs. The cam surface is such that the shutter closes before access to the interlock becomes possible. The return of the shutter to the open position upon the closing of the door may be spring controlled.
Inventors
- 👤 Earl W Robinson
- 👤 De Griek Jr Albert Van
- 👤 Richard W Kisielewski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:32
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6414; H05B6/6417; F; F24; F24C; F24C15/00; F24C15/02; F24C15/022
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
274 words
A positive position interlock concealment shutter for preventing the accidental or intentional actuation of a concealed interlock switch located in the interior of a high frequency energy utilization device having a latch pawl mounted on a door of the device and engaging the interlock switch through a first aperture in a front wall of the device comprising: a shutter assembly mounted substantially adjacent to and in sliding relationship with the interior side of the front wall of the device, said shutter assembly including a first roller connected thereto, a second aperture aligned with said first aperture in the front wall of the device when the door thereof is closed and a solid body portion adjacent to said second aperture; a second roller fixedly mounted within the interior of the device; a door guide arm attached to the door of the devIce and extending into the interior of the device through a third aperture in the front wall of the device, said guide arm including cam means movable over said first and second rollers for controlling the position of said shutter assembly and said second aperture therein in such a manner as to permit sufficient door movement for the latch pawl to clear said second aperture in said shutter assembly during the opening of the door and such that said second aperture in said shutter assembly is misaligned with said first aperture and said solid portion of said shutter assembly is aligned with said first aperture in the front wall of the device as the door thereof is opened, whereby access to the interlock switch is prevented by said solid portion of said shutter assembly.
Claim 2
Dependent Claim
274 words
A positive position interlock concealment shutter for preventing the accidental or intentional actuation of a concealed interlock switch located in the interior of a high frequency energy utilization device having a latch pawl mounted on a door of the device and engaging the interlock switch through a first aperture in a front wall of the device comprising: a shutter assembly mounted substantially adjacent to and in sliding relationship with the interior side of the front wall of the device, said shutter assembly including a first roller connected thereto, a second aperture aligned with said first aperture in the front wall of the device when the door thereof is closed and a solid body portion adjacent to said second aperture; a second roller fixedly mounted within the interior of the device; a door guide arm attached to the door of the devIce and extending into the interior of the device through a third aperture in the front wall of the device, said guide arm including cam means movable over said first and second rollers for controlling the position of said shutter assembly and said second aperture therein in such a manner as to permit sufficient door movement for the latch pawl to clear said second aperture in said shutter assembly during the opening of the door and such that said second aperture in said shutter assembly is misaligned with said first aperture and said solid portion of said shutter assembly is aligned with said first aperture in the front wall of the device as the door thereof is opened, whereby access to the interlock switch is prevented by said solid portion of said shutter assembly.
Claim 3
Dependent Claim
37 words
The device of claim 1 further comprising a shutter stop means mounted on the interior side of the front wall of the device in the path of travel of said shutter assembly for preventing the overtravel thereof.
Claim 4
Dependent Claim
28 words
The device of claim 1 wherein said shutter assembly includes a platform means integral therewith and extending toward the interior of the device for mounting said first roller.
Claim 5
Dependent Claim
53 words
The device of claim 1 further comprising spring means connected to the interior side of the front wall of the device and to said shutter assembly for realigning said second aperture in said shutter assembly with said first aperture in the front wall of the device upon the closing of the door thereof.
Claim 6
Dependent Claim
31 words
The device of claim 1 further comprising spring means connected to said door guide arm and to an interior portion of the device for facilitating the guidance of the door thereof.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |