Patent US3157750A successfully refreshed from Google Patents.
US3157750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic headphone
Assignee: AKG Acoustics GmbH
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Filing: 1961-07-06
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Granted: 1964-11-17
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Expires: 1981-07-06
Abstract
No abstract record available.
Inventors
- 👤 Weingartner Bernhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:58
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/225
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
AN ELECTRODYNAMIC HEADPHONE WHICH COMPRISES A VIBRATORY SYSTEM INCLUDING A DIAPHRAGM HAVING AN EFFECTIVE AREA LARGER THAN THE AVERAGE ENTRANCE AREA OF A HUMAN EAR AND MEANS DEFINING A SMALL-DEPTH AIR CHAMBER WITH THE REAR SIDE OF SAID DIAPHRAGM, SAID HEADPHONE FURTHER COMPRISING MEANS DEFINING AT LEAST ONE OPENING LEADING INTO THE OPEN FROM SAID AIR CHAMBER FOR PRESENTING TO SAID VIBRATORY SYSTEM AN IMPEDANCE WHICH IS MORE DEPENDENT MASS THAN FRICTION SUBSTANTIALLY DOWN THE LOWER END OF THE BASS RANGE AND CAUSING AN AIR MASS IN SAID OPENING TO BE AT RESONANCE IN CONJUNCTION WITH THE RESTORING FORCE OF SAID SMALL-DEPTH AIR CHAMBER, AT A FREQUENCY IN THE RANGE OF 800-5000 CYCLES PER SECOND, WHEREBY THE AIR IN SAID OPENING CONSTITUTES VIBRATING MASS MEANS VIRTUALLY IN PHASE WITH THE DIAPHRAGM THROUGHOUT A SUBSTANTIAL LOW-FREQUENCY RANGE AND THE HEADPHONE WHEN LOOSELY APPLIED TO THE EAR ESTABLISHES A CLOSE-RANGE SOUND FIELD CORRESPONDING TO A FIRST-ORDER OMNIDIRECTIONAL RADIATOR.
Claim 2
Dependent Claim
156 words
AN ELECTRODYNAMIC HEADPHONE WHICH COMPRISES A VIBRATORY SYSTEM INCLUDING A DIAPHRAGM HAVING AN EFFECTIVE AREA LARGER THAN THE AVERAGE ENTRANCE AREA OF A HUMAN EAR AND MEANS DEFINING A SMALL-DEPTH AIR CHAMBER WITH THE REAR SIDE OF SAID DIAPHRAGM, SAID HEADPHONE FURTHER COMPRISING MEANS DEFINING AT LEAST ONE OPENING LEADING INTO THE OPEN FROM SAID AIR CHAMBER FOR PRESENTING TO SAID VIBRATORY SYSTEM AN IMPEDANCE WHICH IS MORE DEPENDENT MASS THAN FRICTION SUBSTANTIALLY DOWN THE LOWER END OF THE BASS RANGE AND CAUSING AN AIR MASS IN SAID OPENING TO BE AT RESONANCE IN CONJUNCTION WITH THE RESTORING FORCE OF SAID SMALL-DEPTH AIR CHAMBER, AT A FREQUENCY IN THE RANGE OF 800-5000 CYCLES PER SECOND, WHEREBY THE AIR IN SAID OPENING CONSTITUTES VIBRATING MASS MEANS VIRTUALLY IN PHASE WITH THE DIAPHRAGM THROUGHOUT A SUBSTANTIAL LOW-FREQUENCY RANGE AND THE HEADPHONE WHEN LOOSELY APPLIED TO THE EAR ESTABLISHES A CLOSE-RANGE SOUND FIELD CORRESPONDING TO A FIRST-ORDER OMNIDIRECTIONAL RADIATOR.
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) | 1967-11-17 | 1968-05-18 | 1968-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-11-17 | 1972-05-18 | 1972-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-11-17 | 1976-05-18 | 1976-11-17 | $7700.00 | Window Closed / Lapsed |