Patent US4980516A successfully refreshed from Google Patents.
US4980516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic-shielding gasket
Assignee: Kitagawa Industries Co Ltd
•
Filing: 1989-10-25
•
Granted: 1990-12-25
•
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 13:10
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.
References Cited (Backward Citations)
US3126440A
Cited
US2885459A
Cited
US3542939A
Cited
US4096459A
Cited
US4288081A
Cited
GB2101621A
Cited
GB2129070A
Cited
EP0113277A1
Cited
US4577872A
Cited
US4769514A
Cited
US4725693A
Cited
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 |