US4307425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Breathing device for a closed housing of a magnetic memory device
Assignee: NTT Inc
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Filing: 1979-10-01
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Granted: 1981-12-22
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Expires: 1999-10-01
Abstract
Abstract In a magnetic memory device wherein a magnetic recording medium is rotated in a substantially closed chamber, there are provided a throttle between the inside and outside of the chamber, a first air fliter for filtering air flowing through the throttle to prevent moisture from entering into the chamber by diffusion, a container containing a desiccating agent and communicated with the chamber, and a second air filter located between the desiccating agent container and the chamber. In a modified embodiment, another throttle is also provided between the desiccating agent container and the substantially closed chamber.
Inventors
- 👤 Reizo Kaneko
- 👤 Akio Tago
- 👤 Shigemitsu Oguchi
- 👤 Shigehisa Hukui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:20
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/50; G11B23/505; G11B23/507
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A breathing device for a closed housing of a magnetic memory device including magnetic memory media and a substantially closed chamber containing said magnetic memory media comprising: a restricted air passage interconnecting the inside and outside of said substantially closed chamber, said restricted air passage having a flow resistance such that the pressure difference between the inside and outside of said chamber is within the range of from 10 to 40 mmWG; a first air filter for filtering air passing through said restricted air passage; a container containing a desiccating agent and communicated with said chamber; and a second air filter located between said desiccating agent container and said chamber.
Claim 2
Dependent Claim
110 words
A breathing device for a closed housing of a magnetic memory device including magnetic memory media and a substantially closed chamber containing said magnetic memory media comprising: a restricted air passage interconnecting the inside and outside of said substantially closed chamber, said restricted air passage having a flow resistance such that the pressure difference between the inside and outside of said chamber is within the range of from 10 to 40 mmWG; a first air filter for filtering air passing through said restricted air passage; a container containing a desiccating agent and communicated with said chamber; and a second air filter located between said desiccating agent container and said chamber.
Claim 3
Dependent Claim
17 words
A breathing device according to claim 1 wherein said magnetic memory media are in the form discs.
Claim 4
Dependent Claim
100 words
A breathing device for a closed housing of a magnetic memory device including magnetic recording media and a substantially closed chamber containing said magnetic memory media comprising: a first restricted air passage interconnecting the inside and outside of said substantially closed chamber; a first air filter for filtering air passing through said first restricted air passage; a container containing a desiccating agent and communicated with said substantially closed chamber; a second restricted air passage disposed between said desiccating agent container and said substantially closed chamber; and a second air filter for filtering air passing through said second restricted air passage.
Claim 5
Dependent Claim
100 words
A breathing device for a closed housing of a magnetic memory device including magnetic recording media and a substantially closed chamber containing said magnetic memory media comprising: a first restricted air passage interconnecting the inside and outside of said substantially closed chamber; a first air filter for filtering air passing through said first restricted air passage; a container containing a desiccating agent and communicated with said substantially closed chamber; a second restricted air passage disposed between said desiccating agent container and said substantially closed chamber; and a second air filter for filtering air passing through said second restricted air passage.
Claim 6
Dependent Claim
37 words
A breathing device according to claim 3 wherein said first restricted air passage has a flow resistance such that the pressure difference between the inside and outside of said substantially closed chamber is less than 40 mmWG.
Claim 7
Dependent Claim
17 words
A breathing device according to claim 3 wherein said pressure difference is from 10 to 40 mmWG.
Claim 8
Dependent Claim
130 words
A breathing device for a closed housing of a magnetic memory device including a magnetic recording medium, a substantially closed chamber containing said magnetic recording medium and means disposed adjacent said substantially closed chamber for driving said magnetic recording medium comprising; a first restricted air passage for intercommunicating the inside and outside of said substantially closed chamber; a first air filter for filtering air passing through said first restricted air passage; a container for containing a desiccating agent and communicated with said substantially closed chamber; a second restricted air passage disposed between said desiccating agent container and said substantially closed chamber; a second air filter for filtering air passing through said second restricted air passage; and a magnetic fluid seal located between said substantially closed chamber and said drive means.
Claim 9
Dependent Claim
130 words
A breathing device for a closed housing of a magnetic memory device including a magnetic recording medium, a substantially closed chamber containing said magnetic recording medium and means disposed adjacent said substantially closed chamber for driving said magnetic recording medium comprising; a first restricted air passage for intercommunicating the inside and outside of said substantially closed chamber; a first air filter for filtering air passing through said first restricted air passage; a container for containing a desiccating agent and communicated with said substantially closed chamber; a second restricted air passage disposed between said desiccating agent container and said substantially closed chamber; a second air filter for filtering air passing through said second restricted air passage; and a magnetic fluid seal located between said substantially closed chamber and said drive means.
References Cited (Backward Citations)
US3620584A
Cited
US4054931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |