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US3777192A Expired / Lapsed US ⏱️ 0.0 years remaining

A method for adjusting the resonant frequency and motional electrical impedance of a vibrating diaphragm electroacoustic transducer

Assignee: MASSA DONALD P COHASSET
•
Filing: 1972-03-20
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Granted: 1973-12-04
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Expires: 1992-03-20
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Abstract

Abstract An operator applies a viscous paste over the surface of a clamped diaphragm in a transducer operating in a flexural resonant mode. The operator literally ''''paints on'''' the desired resonant frequency and impedance characteristic of the transducer. These characteristics are continuously monitored, on a suitable meter, while the operator is applying the paste.

Inventors

  • 👤 G Barrow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 19:53
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/225

Claims Analysis

Total Claims: 38
Claim 1
Independent Claim 121 words
A method of manufacture for adjusting the resonance frequency of an electroacoustic transducer which includes a vibratile diaphragm, said frequency adjusting method including the steps of: a. applying of a non-uniform layer of liquid for forming a thin film of flexible, vibrational lossy material over at least a selected portion of the surface of said vibratile diaphragm, b. observing said diaphragm in a dynamic state while said liquid is being applied to said diaphragm, said selected portions being individually determined for each individiual transducer responsive to the observations, and c. distributing material over the surface of the diaphragm until the desired resonance frequency is obtained, and d. drying said liquid to provide said film in the form selected in step (b).
Claim 2
Independent Claim 121 words
A method of manufacture for adjusting the resonance frequency of an electroacoustic transducer which includes a vibratile diaphragm, said frequency adjusting method including the steps of: a. applying of a non-uniform layer of liquid for forming a thin film of flexible, vibrational lossy material over at least a selected portion of the surface of said vibratile diaphragm, b. observing said diaphragm in a dynamic state while said liquid is being applied to said diaphragm, said selected portions being individually determined for each individiual transducer responsive to the observations, and c. distributing material over the surface of the diaphragm until the desired resonance frequency is obtained, and d. drying said liquid to provide said film in the form selected in step (b).
Claim 3
Dependent Claim 59 words
The method of manufacture set forth in claim 1 wherein the distribution of said non-uniform layer is selected for adjusting the electrical impedance of the electroacoustic transducer which includes said vibratile diaphragm, said adjusting method including the application of said thin film of vibrational lossy material to at least a circular portion of the surface of said vibratile diaphragm.
Claim 4
Dependent Claim 15 words
connecting a variable frequency oscillator to supply a varying frequency electrical signal to the transducer;
Claim 5
Dependent Claim 15 words
connecting a variable frequency oscillator to supply a varying frequency electrical signal to the transducer;
Claim 6
Dependent Claim 17 words
the adjustment of a variable inductance connected in series with said transducer and variable frequency signal generator;
Claim 7
Dependent Claim 17 words
the adjustment of a variable inductance connected in series with said transducer and variable frequency signal generator;
Claim 8
Dependent Claim 46 words
selectively adding a thin non-uniform layer of flexible material over a substantial portion of said diaphragm, said material having a high impedance to mechanical motion and being selectively located on at least those portions of the surface of the diaphragm which vibrates at higher amplitudes; and
Claim 9
Dependent Claim 46 words
selectively adding a thin non-uniform layer of flexible material over a substantial portion of said diaphragm, said material having a high impedance to mechanical motion and being selectively located on at least those portions of the surface of the diaphragm which vibrates at higher amplitudes; and
Claim 10
Dependent Claim 32 words
selectively adding a thin layer of flexible vibrational lossy material to at least a circular portion of a surface of the diaphragm radially disposed about and away from the center thereof; and
Claim 11
Dependent Claim 32 words
selectively adding a thin layer of flexible vibrational lossy material to at least a circular portion of a surface of the diaphragm radially disposed about and away from the center thereof; and
Claim 12
Dependent Claim 13 words
connecting a motional impedance indicating meter across said transducer and series variable inductance;
Claim 13
Dependent Claim 13 words
connecting a motional impedance indicating meter across said transducer and series variable inductance;
Claim 14
Dependent Claim 15 words
distributing the material over the diaphragm surface until the desired magnitude of impedance is measured.
Claim 15
Dependent Claim 15 words
distributing the material over the diaphragm surface until the desired magnitude of impedance is measured.
Claim 16
Dependent Claim 15 words
observing the two dimensional graphical display of impedance versus frequency on said impedance measuring instrument;
Claim 17
Dependent Claim 15 words
observing the two dimensional graphical display of impedance versus frequency on said impedance measuring instrument;
Claim 18
Dependent Claim 18 words
locally and non-uniformly adjusting the amounts of said added material until the resonant frequency measures the desired value.
Claim 19
Dependent Claim 18 words
locally and non-uniformly adjusting the amounts of said added material until the resonant frequency measures the desired value.
Claim 20
Dependent Claim 61 words
The method of manufacture set forth in claim 1 wherein the distribution of said non-uniform layer is selected for adjusting both the resonance frequency and the electrical impedance of the electroacoustic transducer which includes said vibratile diaphragm, said adjusting means including a thin film of rubbery material attached to at least a circular portion of the surface of said vibratile diaphragm.
Claim 21
Dependent Claim 20 words
adjusting said variable inductor until the meter indicates that the impedance magnitude at the resonance peak value is a minimum;
Claim 22
Dependent Claim 20 words
adjusting said variable inductor until the meter indicates that the impedance magnitude at the resonance peak value is a minimum;
Claim 23
Dependent Claim 23 words
distributing a controlled non uniform layer of soft and flexible adhesive material over a substantial portion of the surface of said transducer; and
Claim 24
Dependent Claim 23 words
distributing a controlled non uniform layer of soft and flexible adhesive material over a substantial portion of the surface of said transducer; and
Claim 25
Independent Claim 22 words
A method of lowering the resonant frequency of an electroacoustic transducer which includes a vibratile diaphragm, said method including the following steps:
Claim 26
Independent Claim 22 words
A method of lowering the resonant frequency of an electroacoustic transducer which includes a vibratile diaphragm, said method including the following steps:
Claim 27
Independent Claim 26 words
A method of adjusting the magnitude of the motional electrical impedance of an electroacoustic transducer which includes a vibratile diaphragm, said method including the following steps:
Claim 28
Independent Claim 26 words
A method of adjusting the magnitude of the motional electrical impedance of an electroacoustic transducer which includes a vibratile diaphragm, said method including the following steps:
Claim 29
Dependent Claim 32 words
selectively varying the local amount and distribution pattern of said adhesive material in a random manner until the observed impedance versus frequency characteristic indicates the desired resonance frequency and desired impedance magnitude.
Claim 30
Dependent Claim 32 words
selectively varying the local amount and distribution pattern of said adhesive material in a random manner until the observed impedance versus frequency characteristic indicates the desired resonance frequency and desired impedance magnitude.
Claim 31
Dependent Claim 39 words
applying a thin film of material with a vibrational loss characteristic to at least a portion of the surface of the diaphragm and adjusting the amount of said applied material to move the resonance to a desired frequency; and
Claim 32
Dependent Claim 39 words
applying a thin film of material with a vibrational loss characteristic to at least a portion of the surface of the diaphragm and adjusting the amount of said applied material to move the resonance to a desired frequency; and
Claim 33
Dependent Claim 31 words
spreading the film of said material to specific regions of the diaphragm surface until the magnitude of the motional impedance at the resonance peak value is adjusted to the desired value.
Claim 34
Dependent Claim 31 words
spreading the film of said material to specific regions of the diaphragm surface until the magnitude of the motional impedance at the resonance peak value is adjusted to the desired value.
Claim 35
Dependent Claim 28 words
A manufacturing method of adjusting the resonant frequency and electrical impedance of an electroacoustic transducer comprising a vibratile diaphragm driven by a polarized ceramic element, said method including:
Claim 36
Dependent Claim 28 words
A manufacturing method of adjusting the resonant frequency and electrical impedance of an electroacoustic transducer comprising a vibratile diaphragm driven by a polarized ceramic element, said method including:
Claim 37
Independent Claim 24 words
A method for adjusting the resonance frequency and the motional impedance of an electroacoustic transducer of the vibratile diaphragm type including the following steps:
Claim 38
Independent Claim 24 words
A method for adjusting the resonance frequency and the motional impedance of an electroacoustic transducer of the vibratile diaphragm type including the following steps:

References Cited (Backward Citations)

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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) 1976-12-03 1977-06-04 1977-12-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-12-03 1981-06-04 1981-12-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-12-03 1985-06-04 1985-12-04 $7700.00 Window Closed / Lapsed

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