US3903733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of measuring vibrations by means of piezoelectric body and the apparatus therefor
Assignee: Kureha Corp
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Filing: 1973-11-20
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Granted: 1975-09-09
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Expires: 1993-11-20
Abstract
Abstract Method of measuring mechanical vibrations comprises forming an electric circuit including as its terminals electrodes provided on both sides of a high molecular piezoelectric body, coupling said piezoelectric body entirely or partially to a vibrating body to be measured, and measuring or detecting the mechanical vibrations by transforming them into changes in an electric quantity or in voltage. Measuring apparatus for use with the above method are also disclosed comprising a high molecular piezoelectric body the terminals of which are connected by way of an FET to a measuring or detecting device.
Inventors
- 👤 Naohiro Murayama
- 👤 Takao Oikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:18
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/02; G01N29/036; G01H; G01H11/00; G01H11/06; G01H11/08; G01N2291/00; G01N2291/02; G01N2291/025; G01N2291/0256; Y; Y10; Y10S; Y10S310/00; Y10S310/80; Y10S73/00; Y10S73/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
45 words
APPARATUS FOR DETECTING VIBRATIONS COMPRISING AN ELECTRICALLY POLARIZED HIGH MOLECULAR POLYMER PIEZOELECTRIC BODY SUBJECT TO THE VIBRATIONS AND PROVIDED WITH ELECTRODES ON OPPOSITE SIDES THEREOF, SAID BODY CONVERTING THE VIBRATION TO CORRESPONDING VOLTAGE VARIATIONS BETWEEN SAID ELECTRODES, AND DETECTOR MEANS FOR DETECTING THE VOLTAGE VARIATIONS.
Claim 2
Dependent Claim
45 words
APPARATUS FOR DETECTING VIBRATIONS COMPRISING AN ELECTRICALLY POLARIZED HIGH MOLECULAR POLYMER PIEZOELECTRIC BODY SUBJECT TO THE VIBRATIONS AND PROVIDED WITH ELECTRODES ON OPPOSITE SIDES THEREOF, SAID BODY CONVERTING THE VIBRATION TO CORRESPONDING VOLTAGE VARIATIONS BETWEEN SAID ELECTRODES, AND DETECTOR MEANS FOR DETECTING THE VOLTAGE VARIATIONS.
Claim 3
Dependent Claim
36 words
Apparatus as defined in claim 1 in which said high molecular piezoelectric body provided with electrodes at opposite sides thereof is fixed to a vibrating body by pressure sensitive adhesives previously applied on one side thereof.
Claim 4
Dependent Claim
17 words
Apparatus as defined in claim 1, wherein said piezoelectric body is an electrically polarized polyvinylidene fluoride film.
Claim 5
Dependent Claim
20 words
Apparatus as defined in claim 3, wherein said film has a piezoelectric constant of approximately 4.0 X 10 7 cgsesu.
Claim 6
Dependent Claim
29 words
Apparatus as defined in claim 3 wherein said film is monoaxially oriented and has a piezoelectric constant of between 1 X 10 7 and 2 X 10 6 cgsesu.
Claim 7
Dependent Claim
26 words
Apparatus as defined in claim 1, further comprising field effect transistor circuit means connected to said electrodes for coupling the voltage variations to said detector means.
Claim 8
Dependent Claim
44 words
Apparatus as defined in claim 6 wherein said detector means comprises an alarm device, and further comprising voltagesensitive means coupled between said circuit means and said alarm device for energizing said alarm device when the level of the voltage variations exceeds a predetermined value.
Claim 9
Dependent Claim
17 words
Apparatus as defined in claim 6, wherein said piezoelectric body is an electrically polarized polyvinylidene fluoride film.
Claim 10
Independent Claim
74 words
A method of measuring mechanical vibrations comprising: polarizing a high molecular polymer piezoelectric body by applying a d.c. electric field thereto; forming an electric circuit including electrodes secured to opposite sides of the polarized body; mechanically coupling the polarized body to a mechanically vibrating body, whereby the mechanical vibrations of the body are converted into corresponding electrical changes in the electrical circuit; and detecting the electrical changes as a measure of the mechanical vibrations.
Claim 11
Independent Claim
74 words
A method of measuring mechanical vibrations comprising: polarizing a high molecular polymer piezoelectric body by applying a d.c. electric field thereto; forming an electric circuit including electrodes secured to opposite sides of the polarized body; mechanically coupling the polarized body to a mechanically vibrating body, whereby the mechanical vibrations of the body are converted into corresponding electrical changes in the electrical circuit; and detecting the electrical changes as a measure of the mechanical vibrations.
Claim 12
Dependent Claim
25 words
A method as defined in claim 9, further comprising the step of selecting the high molecular piezoelectric body as a high polymer polyvinylidene fluoride film.
Claim 13
Dependent Claim
34 words
A method as defined in claim 10, wherein the field-applying step comprises applying a field of approximately 500 KV/cm to produce piezoelectric constant of approximately 4.0 X 10 7 cgsesu in said piezoelectric body.
Claim 14
Dependent Claim
37 words
A method as defined in claIm 10 wherein said film is monoaxially oriented, and wherein said field-applying step produces in said film a piezoelectric constant of between 1 X 10 7 and 2 X 10 6 cgsesu.
Claim 15
Dependent Claim
32 words
A method as defined in claim 9, wherein the coupling step further comprises fixing one end of the polarized body to a stationary body and the other end to the vibrating body.
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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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |