US4629925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric coaxial cable
Assignee: Raychem Ltd
•
Filing: 1984-11-20
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Granted: 1986-12-16
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Expires: 2004-11-20
Abstract
Abstract A piezoelectric coaxial cable comprises a central stretchable electrical conductor (1), preferably formed from a low melting point metal alloy, a piezoelectric intermediate layer (2), preferably formed from a vinylidene fluoride polymer which has been stretched and radially polarized to render it piezoelectric, and an outer electrical conductor (3). The intermediate layer has a ratio R of its internal radius to its external radius which is preferably not more than 0.5 and especially not more than 0.4. This construction enables coaxial cables to be formed without voiding or breaking of the internal conductor during stretching.
Inventors
- 👤 Michael Booth
- 👤 Richard J. Penneck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:14
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/60; H10N30/01; H10N30/04; H10N30/045; H10N30/09; H10N30/098; Y; Y10; Y10S; Y10S310/00; Y10S310/80; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
54 words
A piezoelectric coaxial cable, which comprises a central electrical conductor and an intermediate piezoelectric layer, the central conductor and the intermediate layer having been axially stretched and the intermediate layer having been radially polarized to render it piezoelectric, and the intermediate layer having an internal radius that is about 0.33 times its external radius.
Claim 2
Dependent Claim
54 words
A piezoelectric coaxial cable, which comprises a central electrical conductor and an intermediate piezoelectric layer, the central conductor and the intermediate layer having been axially stretched and the intermediate layer having been radially polarized to render it piezoelectric, and the intermediate layer having an internal radius that is about 0.33 times its external radius.
Claim 3
Dependent Claim
82 words
A piezoelectric coaxial cable, which comprises a central electrical conductor, an outer electrical conductor and an intermediate piezoelectric layer, the central conductor and the intermediate layer having been axially stretched and the intermediate layer having been radially polarized to render it piezoelectric, the intermediate layer having a ratio R of its internal radius to its external radius which: (a) is less than 0.5; and (b) satisfies the inequality: R≦0.67-0.55T wherein T is the wall thickness of the intermediate layer, measured in millimeters.
Claim 4
Dependent Claim
82 words
A piezoelectric coaxial cable, which comprises a central electrical conductor, an outer electrical conductor and an intermediate piezoelectric layer, the central conductor and the intermediate layer having been axially stretched and the intermediate layer having been radially polarized to render it piezoelectric, the intermediate layer having a ratio R of its internal radius to its external radius which: (a) is less than 0.5; and (b) satisfies the inequality: R≦0.67-0.55T wherein T is the wall thickness of the intermediate layer, measured in millimeters.
Claim 5
Dependent Claim
22 words
A cable as claimed in claim 1 or 2 wherein the intermediate layer has a wall thickness of at least 0.3 mm.
Claim 6
Dependent Claim
18 words
A cable as claimed in claim 1 or 2, wherein the intermediate layer comprises a vinylidine fluoride polymer.
Claim 7
Dependent Claim
26 words
A cable as claimed in claim 1 or 2, wherein the central conductor has a melting point in the range of from 50° to 150° C.
Claim 8
Dependent Claim
28 words
A cable as claimed in claim 1 or 2, wherein the central conductor is formed from a metal that increases in volume as it solidifies from the melt.
Claim 9
Dependent Claim
28 words
A cable as claimed in claim 3 or 4, wherein the central conductor is formed from a metal having a melting point of not more than 170° C.
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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) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |