US4980516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic-shielding gasket
Assignee: Kitagawa Industries Co Ltd
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Filing: 1989-10-25
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Granted: 1990-12-25
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Expires: 2009-10-25
Abstract
Abstract An electromagnetic-shielding gasket of this invention is composed of an elastic body. The elastic body contains a filler of whisker-shaped carbon fiber with a micro diameter. The carbon fiber is developed from ultrafine particles of a high-melting metal and/or the compound of the high-melting metal through a vapor-phase system. The carbon fiber developed in the vapor phase is uniformly dispersed in the elastic body. Consequently, the electromagnetic-shielding gasket has a uniform low electric resistivity and an elasticity. By fitting the electromagnetic-shielding gasket onto gaps in the housing of electronic components, the housing is kept watertight and airtight, and electromagnetic waves are prevented from passing through the gaps.
Inventors
- 👤 Asaharu Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:47
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0007; H05K9/0015; Y; Y10; Y10S; Y10S277/00; Y10S277/919; Y10S277/92; Y10S277/935; Y10S277/936; Y10S277/938
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
110 words
A conductive seal for filling a gap between first and second surfaces, comprising: a body of elastic material composed of an elastomer chosen from the group consisting of chloroprene rubber, silicone rubber, polyurethane rubber, crude rubber, and soft foam synthetic resin; said body of elastic material having interlaced carbon fibers distributed in the body such that the body is electrically conductive; said carbon fibers having an elasticity of substantially 20 t/mm 2 and a volume resistivity of substantially 0.001 ohmcentimeters; and wherein said carbon fibers are developed through a vapor-phase cracking process by using particles of a high-melting point metal or compounds thereof which have a diameter of 0.02-0.03 microns.
Claim 2
Dependent Claim
110 words
A conductive seal for filling a gap between first and second surfaces, comprising: a body of elastic material composed of an elastomer chosen from the group consisting of chloroprene rubber, silicone rubber, polyurethane rubber, crude rubber, and soft foam synthetic resin; said body of elastic material having interlaced carbon fibers distributed in the body such that the body is electrically conductive; said carbon fibers having an elasticity of substantially 20 t/mm 2 and a volume resistivity of substantially 0.001 ohmcentimeters; and wherein said carbon fibers are developed through a vapor-phase cracking process by using particles of a high-melting point metal or compounds thereof which have a diameter of 0.02-0.03 microns.
Claim 3
Dependent Claim
23 words
The conductive seal of claim 1, wherein the content of carbon fiber in the elastic body is between 15% and 60% by weight.
Claim 4
Dependent Claim
28 words
The conductive seal of claim 1, wherein the carbon fibers have a diameter between 0.1 microns to 0.5 microns and a length between 0.1 millimeter and 1.0 millimeters.
Claim 5
Dependent Claim
21 words
The conductive seal of claim 1, wherein the carbon fibers distributed in the body longitudinally deflect when the body is compressed.
Claim 6
Dependent Claim
68 words
The conductive seal of claim 1, wherein the first surface is a conductive surface on a housing means for housing electrical components, the second surface is a conductive surface on a covering means for covering an opening in the housing means, and the elastic body is formed into a gasket that forms an airtight, watertight seal around the opening and prevents electromagnetic noise from passing through the opening.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |