US3573394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric microphone with biasing means
Assignee: IND SCIENT RESEARCH CORP
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Filing: 1967-09-14
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Granted: 1971-04-06
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Expires: 1987-09-14
Abstract
Abstract A cardio-microphone comprising a piezoelectric crystal disc, mounted on a knife edge on a supporting ring, and embedded in a generally disc-shaped silicone rubber housing that has a dome on one side surrounded by an annular seating surface to be seated against the body of a patient. The dome projects beyond the seating surface, and, when it and the annular seating surface engage the body of the patient, the crystal disc on the inside receives center pressure which forces it into a dished shape and thereby provides it with a preliminary bias.
Inventors
- 👤 William S Birnbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:25
CPC Classifications
H; H04; H04R; H04R17/00; H04R17/02; H04R1/00; H04R1/46
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A microphone comprising: a generally circular, normally flat crystal disc; a substantially rigid annular ring having an annular knife-edge at one end thereof facing in a direction parallel to the axis of said ring, said knife-edge engaging one face of said crystal disc adjacent its periphery; cementitious material rigidly securing said ring to said disc to fixedly hold said knife-edge thereagainst; and a flexible rubber body having said disc and ring completely embedded therein, said rubber body having an outer surface, outwardly of said one face of said disc adapted to engage a patient''s body and transmit vibrations therefrom to said disc.
Claim 2
Dependent Claim
102 words
A microphone comprising: a generally circular, normally flat crystal disc; a substantially rigid annular ring having an annular knife-edge at one end thereof facing in a direction parallel to the axis of said ring, said knife-edge engaging one face of said crystal disc adjacent its periphery; cementitious material rigidly securing said ring to said disc to fixedly hold said knife-edge thereagainst; and a flexible rubber body having said disc and ring completely embedded therein, said rubber body having an outer surface, outwardly of said one face of said disc adapted to engage a patient''s body and transmit vibrations therefrom to said disc.
Claim 3
Dependent Claim
30 words
A microphone as defined in claim 1 wherein said cementitious material extends outwardly from said ring to cover the outer face portion of said disc and the peripheral edge thereof.
Claim 4
Dependent Claim
41 words
A microphone as defined in claim 1 wherein said outer surface of said rubber body is shaped to define a projection substantially centrally of said disc whereby external pressure applied to said projection causes said disc to bow slightly, away therefrom.
Claim 5
Dependent Claim
69 words
A microphone as defined in claim 1 wherein said outer surface of said rubber body is provided with a flat annular surface portion, defining a plane substantially parallel to the plane of said disc, and surrounding said projection; said projection extending outwardly beyond the plane of said annular surface portion whereby said annular surface portion serves to engage a patient''s body and thereby limit the bowing of said disc.
Claim 6
Dependent Claim
31 words
A microphone as defined in claim 3 wherein the portion of said outer surface between said projection and said annular surface portion is nearer said disc than said annular surface portion.
Claim 7
Dependent Claim
20 words
A microphone as defined in claim 3 including a metal ring having a surface flush with said annular surface portion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |