Patent US4424974A successfully refreshed from Google Patents.
US4424974A
Expired / Lapsed
US
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Ferro fluidic seal
Assignee: NTT Inc
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Filing: 1982-07-28
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Granted: 1984-01-10
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Expires: 2002-07-28
Abstract
Abstract An improved ferro fluidic seal assembly having a cylindrical permanent magnet, a pair of ring-shaped yokes coupled coaxially with said magnet, and a fresh fluid storage containing ferro magnetic fluid mounted in a room defined by said magnet and yokes. Said fresh fluid storage is composed of a resilient elongated member like a stainless steel belt adapted and fixed in a circular shape along the surface of the magnet, and supplies fresh fluid to the clearance gaps defined between said yokes and a rotational body to seal said clearance gaps.
Inventors
- 👤 Yasunaga Mitsuya
- 👤 Kunio Hoshiya
- 👤 Shigemitsu Oguchi
- 👤 Reizo Kaneko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:44
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; F16J15/43; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/944
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
168 words
A ferro fluidic seal comprising: a seal assembly comprising a substantially cylindrical permanent magnet magnetized in the axial direction of the same, a pair of ring shaped yokes made of ferro-magnetic material coupled coaxially with said permanent magnet, and a fresh fluid storage containing fluid with ferro magnetic property mounted in a room defined by said magnet and the yokes, a rotational body rotational relative to said seal assembly, said rotational body being arranged coaxially with said seal assembly so that thin clearance gaps are provided between the rotational body and the yokes, and said rotational body being made of ferro-magnetic material, fluid contained in said fresh fluid storage being communicated with said clearance gaps between the yokes and the rotational body to seal said gaps, said fresh fluid storage comprising a resilient elongated member adapted in a circular shape along the surface of said cylindrical permanent magnet, and said member being fixed on the surface of the permanent magnet with a spring action by said member itself.
Claim 2
Dependent Claim
168 words
A ferro fluidic seal comprising: a seal assembly comprising a substantially cylindrical permanent magnet magnetized in the axial direction of the same, a pair of ring shaped yokes made of ferro-magnetic material coupled coaxially with said permanent magnet, and a fresh fluid storage containing fluid with ferro magnetic property mounted in a room defined by said magnet and the yokes, a rotational body rotational relative to said seal assembly, said rotational body being arranged coaxially with said seal assembly so that thin clearance gaps are provided between the rotational body and the yokes, and said rotational body being made of ferro-magnetic material, fluid contained in said fresh fluid storage being communicated with said clearance gaps between the yokes and the rotational body to seal said gaps, said fresh fluid storage comprising a resilient elongated member adapted in a circular shape along the surface of said cylindrical permanent magnet, and said member being fixed on the surface of the permanent magnet with a spring action by said member itself.
Claim 3
Dependent Claim
53 words
A ferro fluidic seal according to claim 1, wherein said rotational body is a spindle rotationally arranged in said seal assembly, said seal assembly is fixed to a housing, and said fresh fluid storage is defined by the outer surface of the spindle, the yokes and the inner surface of the permanent magnet.
Claim 4
Dependent Claim
57 words
A ferro fluidic seal according to claim 1, wherein said rotational body is a hollow cylindrical body rotationally arranged around said seal assembly, said seal assembly is fixed to a housing, and said fresh fluid storage is defined by the inner surface of the hollow cylindrical body, the yokes and the outer surface of the permanent magnet.
Claim 5
Dependent Claim
23 words
A ferro fluidic seal according to claim 1, wherein said fresh fluid storage has a plurality of coaxial belts laminated to each other.
Claim 6
Dependent Claim
19 words
A ferro fluidic seal according to claim 1, wherein said fresh fluid storage is a coil of a belt.
Claim 7
Dependent Claim
34 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a belt having a plurality of slits on the surface of the belt in a lateral direction of the belt.
Claim 8
Dependent Claim
34 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a belt having a plurality of slits on the surface of the belt in a longitudinal direction of the belt.
Claim 9
Dependent Claim
27 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a belt having a plurality of projections on the surface of the belt.
Claim 10
Dependent Claim
26 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a waveshaped belt with a series of parallel furrows separated by ridges.
Claim 11
Dependent Claim
21 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a belt having a plurality of through-holes.
Claim 12
Dependent Claim
21 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a belt having a plurality of half-holes.
Claim 13
Dependent Claim
17 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a flat belt.
Claim 14
Dependent Claim
21 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is a wire wound along the permanent magnet.
Claim 15
Dependent Claim
37 words
A ferro fluidic seal according to claim 1, wherein said fresh storage is further composed of second ring sandwiched between said elongated member and the permanent magnet, and said second ring has the nature to keep liquid.
Claim 16
Dependent Claim
16 words
A ferro fluidic seal according to claim 14, wherein more than two second rings are provided.
Claim 17
Dependent Claim
23 words
A ferro fluidic seal according to claim 14, wherein more than two resilient elongated members and more than two second rings are provided.
Claim 18
Dependent Claim
18 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is made of stainless steel.
Claim 19
Dependent Claim
18 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is made of phosphor bronze.
Claim 20
Dependent Claim
17 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is made of beryllium-copper.
Claim 21
Dependent Claim
16 words
A ferro fluidic seal according to claim 1, wherein said resilient elongated member is resilient plastics.
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) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |