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US3862477A Expired / Lapsed US ⏱️ 0.0 years remaining

Poling process for linear piezoelectric strain transducers

Assignee: Hughes Missile Systems Co
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Filing: 1973-08-16
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Granted: 1975-01-28
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Expires: 1993-08-16
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Abstract

Abstract A process for producing sufficient piezoelectric effect in plastic dielectric coaxial cable to obtain a highly sensitive linear strain transducer. The process combines a selected soak temperature profile with the application of high voltage DC to maximize sensitivity and uniformity. The plastic dielectric material exhibits a high level of piezoelectric activity when processed according to the invention so that, for example, the cable is sensitive to the passage of humans or vehicles when buried in the ground.

Inventors

  • 👤 Weston D Ayers
  • 👤 Joseph G Hirsch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 10:40
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/01; G08B; G08B13/00; G08B13/20; H; H01; H01B; H01B13/00; H01B13/016; H01B13/0167; H10; H10N; H10N30/00; H10N30/60; Y; Y10; Y10S; Y10S310/00; Y10S310/80; Y10T; Y10T29/00; Y10T29/42

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 160 words
A method of poling manufactured coaxial cable having a plastic dielectric material disposed intermediate the inner conductor and the outer shield conductor of the cable to produce a linear piezoelectric transducer comprising the steps of: padding the barrel portion of a poling drum; loosely winding a length of the manufactured coaxial cable around said padded barrel portion of said drum; dressing the outer end of said cable to obtain a minimum of a 1 inch air gap between tHe inner conductor and the outer shield conductor of said cable; placing said drum holding said cable in a temperature chamber; connecting a source of high voltage to the dressed end of said cable between the inner conductor and the outer shield conductor of said cable; heating said chamber and said cable to an elevated temperature; cooling said chamber and said cable; disconnecting said source of high voltage; and aging said cable to overcome its high initial piezoelectric sensitivity which decays exponentially.
Claim 2
Independent Claim 160 words
A method of poling manufactured coaxial cable having a plastic dielectric material disposed intermediate the inner conductor and the outer shield conductor of the cable to produce a linear piezoelectric transducer comprising the steps of: padding the barrel portion of a poling drum; loosely winding a length of the manufactured coaxial cable around said padded barrel portion of said drum; dressing the outer end of said cable to obtain a minimum of a 1 inch air gap between tHe inner conductor and the outer shield conductor of said cable; placing said drum holding said cable in a temperature chamber; connecting a source of high voltage to the dressed end of said cable between the inner conductor and the outer shield conductor of said cable; heating said chamber and said cable to an elevated temperature; cooling said chamber and said cable; disconnecting said source of high voltage; and aging said cable to overcome its high initial piezoelectric sensitivity which decays exponentially.
Claim 3
Dependent Claim 20 words
The method of claim 1 wherein: said source of high voltage has a potential of substantially 10, 000 volts DC.
Claim 4
Dependent Claim 25 words
The method of claim 1 wherein: said cable has a polyethylene dielectric, and said chamber is heated to a temperature in excess of 180* F.
Claim 5
Dependent Claim 14 words
The method of claim 3 wherein: said chamber is heated to substantially 200* F.
Claim 6
Dependent Claim 18 words
The method of claim 3 wherein: said chamber is held at said elevated temperature for substantially 7 hours.
Claim 7
Dependent Claim 20 words
The method of claim 5 wherein: said chamber is cooled to room temperature over a period of substantially 16 hours.
Claim 8
Dependent Claim 22 words
The method of claim 5 wherein: said chamber is cooled at an initial rate not in excess of 5* F per hour.

References Cited (Backward Citations)

US2900536A Cited
US3820208A Cited
US3750127A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-01-27 1978-07-29 1979-01-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-01-27 1982-07-29 1983-01-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-01-27 1986-07-29 1987-01-28 $7700.00 Window Closed / Lapsed

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