Patent US3917433A successfully refreshed from Google Patents.
US3917433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for opening and closing shutter of ventilating fan
Assignee: Hitachi Ltd
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Filing: 1974-02-12
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Granted: 1975-11-04
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Expires: 1994-02-12
Abstract
Abstract In a device for opening and closing the shutter of a ventilating fan, in which the circuit of the motor to drive the fan is opened after the shutter has been closed by the rotational force of the motor, a mechanism is provided such that the rotational force of the motor after the closure of the shutter may not act as a force urging the shutter in the direction of the closure thereof.
Inventors
- 👤 Tokuhiro Tomitaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:04
CPC Classifications
F; F04; F04D; F04D25/00; F04D25/02; F04D25/08; F04D25/12; F04D25/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
In a device for opening and closing the shutter of a ventilating fan, the improvement comprising a shutter mechanism including shutter blades having respective opening and closing positions, first means for applying a force to said shutter mechanism to urge said shutter blades to the opening position, motor means for rotating said ventilating fan, second means coupled to said motor means for selectively moving said shutter blades into said opening and closing positions, said second means utilizing the rotational force of said motor means to overcome said force of said first means such that said shutter blades are moved into said closing position, and said second means releasing the effect of said rotational force such that said shutter blades are moved into said opening position, and third means coupled to said second means for preventing said rotational force from exceeding the closure force for maintaining said shutter blades in the closing position after said closing position has been achieved.
Claim 2
Dependent Claim
159 words
In a device for opening and closing the shutter of a ventilating fan, the improvement comprising a shutter mechanism including shutter blades having respective opening and closing positions, first means for applying a force to said shutter mechanism to urge said shutter blades to the opening position, motor means for rotating said ventilating fan, second means coupled to said motor means for selectively moving said shutter blades into said opening and closing positions, said second means utilizing the rotational force of said motor means to overcome said force of said first means such that said shutter blades are moved into said closing position, and said second means releasing the effect of said rotational force such that said shutter blades are moved into said opening position, and third means coupled to said second means for preventing said rotational force from exceeding the closure force for maintaining said shutter blades in the closing position after said closing position has been achieved.
Claim 3
Dependent Claim
39 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 1, wherein said first means includes a spring member coupled to said shutter mechanism to urge said shutter blades to said opening position.
Claim 4
Dependent Claim
59 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 1, wherein said second means includes a transmission mechanism selectively coupled to said motor means for transmitting the effect of said rotational force to said shutter mechanism, said second means further including fourth means for disconnecting said transmission mechanism from said motor means.
Claim 5
Dependent Claim
44 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 3, wherein said third means includes a sliding coupling mechanism in said transmission mechanism to release said rotational force from acting after said cLosing position has been achieved.
Claim 6
Dependent Claim
66 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 4, wherein said transmission mechanism includes two cog wheels mounted for rotation together, and said sliding coupling mechanism includes a plurality of balls releasably mounted in connection with said two cog wheels to enable only one of said two cog wheels to rotate when said closing position has been obtained.
Claim 7
Dependent Claim
64 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 3, wherein said second means further includes a switch means for selectively coupling said transmission means to said motor means, and for selectively coupling said fourth means to said motor means, said fourth means including an electromagnetic clutch mechanism for disconnecting said transmission mechanism from said motor means.
Claim 8
Dependent Claim
89 words
A device for opening and closing the shutter of a ventilating fan, as claimed in claim 4, wherein said transmission mechanism includes two cog wheels mounted for rotation together, and said sliding coupling mechanism includes a pair of friction discs, each of said pair of friction discs being mounted in connection with a respective one of said two cog wheels for coupling said two cog wheels, and said pair of friction discs being mounted for sliding contact with respect to one another when said closing position has been obtained.
References Cited (Backward Citations)
US3536413A
Cited
US3589267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |