US3686446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Push-pull moving coil loudspeaker having electromagnetic centering means
Assignee: Individual
•
Filing: 1969-12-16
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Granted: 1972-08-22
•
Expires: 1989-12-16
Abstract
Abstract An electrodynamic acoustic transducer such as a loudspeaker or microphone in which the datum or center position of the diaphragm is determined by two coils. The coils are fixed to one another and to the diaphragm and cut magnetic fields. Datum currents are provided for the coils and the coils are of non-uniform density of winding and/or the magnetic fields are non-uniform. The coils and the datum currents are arranged to provide balanced forces on the coils only when the diaphragm is in the datum position.
Inventors
- 👤 Josef W Manger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:16
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02; H04R9/00; H04R9/02; H04R9/04; H04R9/041; H04R9/06; H04R9/063
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
156 words
In an electrodynamic acoustic transducer with a vibratory diaphragm, the provision of centering means for returning the diaphragm to a datum position and including a. two moving coils, b. means for providing magnetic fields cutting said coils, c. mechanical means connecting said coils to one another and to said diaphragm, c''. said vibratory diaphragm being arranged to vibrate without any mechanical restraining element affixed between said mechanical means and said means for providing magnetic fields cutting said coils, and d. means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position, said diaphragm being returned to said datum position solely by electromagnetic forces, said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils, and said two moving coils being spaced apart from each other along the direction of said common axis.
Claim 2
Dependent Claim
156 words
In an electrodynamic acoustic transducer with a vibratory diaphragm, the provision of centering means for returning the diaphragm to a datum position and including a. two moving coils, b. means for providing magnetic fields cutting said coils, c. mechanical means connecting said coils to one another and to said diaphragm, c''. said vibratory diaphragm being arranged to vibrate without any mechanical restraining element affixed between said mechanical means and said means for providing magnetic fields cutting said coils, and d. means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position, said diaphragm being returned to said datum position solely by electromagnetic forces, said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils, and said two moving coils being spaced apart from each other along the direction of said common axis.
Claim 3
Dependent Claim
11 words
A transducer according to claim 1, wherein said fields are inhomogeneous.
Claim 4
Dependent Claim
16 words
A transducer according to claim 1, wherein said coils are wound with non-uniform density of winding.
Claim 5
Dependent Claim
15 words
A transducer according to claim 1, wherein said magnetic fields are provided by pot magnets.
Claim 6
Dependent Claim
14 words
A transducer according to claim 4, wherein said pot magnets open towards one another.
Claim 7
Dependent Claim
131 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils being coaxial; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; said magnetic fields being provided by pot magnets; and wherein said pot magnets open away from one another.
Claim 8
Dependent Claim
131 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils being coaxial; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; said magnetic fields being provided by pot magnets; and wherein said pot magnets open away from one another.
Claim 9
Dependent Claim
19 words
A transducer according to claim 6, wherein said forces acting oppositely on said coils act away from one another.
Claim 10
Dependent Claim
153 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils being coaxial; said diaphragm being returned to said datum position solely by electromagnetic forces; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; said magnetic fields being provided by pot magnets; said pot magnets open towards one another; and wherein said forces acting oppositely on said coils act towards one another.
Claim 11
Dependent Claim
153 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils being coaxial; said diaphragm being returned to said datum position solely by electromagnetic forces; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; said magnetic fields being provided by pot magnets; said pot magnets open towards one another; and wherein said forces acting oppositely on said coils act towards one another.
Claim 12
Dependent Claim
137 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; said diaphragm being returned to said datum position solely by electromagnetic forces; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; and wherein said coils are coaxial and said fields are provided by a single pot magnet.
Claim 13
Dependent Claim
137 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two moving coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; said diaphragm being returned to said datum position solely by electromagnetic forces; said two moving coils having a common axis disposed perpendicular to lines of flux of said magnetic fields cutting said coils; said two moving coils being spaced apart from each other along the direction of said common axis; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; and wherein said coils are coaxial and said fields are provided by a single pot magnet.
Claim 14
Dependent Claim
36 words
A transducer according to claim 1, wherein said coils of the centering means are also operating coils of the transducer and said datum currents are superimposed upon operating currents and produce out-of-balance forces on said coils.
Claim 15
Dependent Claim
28 words
A transducer according to claim 1, wherein said coils, said magnetic-field providing means, and said mechanical means are surrounded by a hollow body rigidly connected to said coils.
Claim 16
Dependent Claim
13 words
A transducer according to claim 11, wherein said hollow body carries said diaphragm.
Claim 17
Dependent Claim
15 words
A transducer according to claim 11, wherein said diaphragm is mounted upon said hollow body.
Claim 18
Dependent Claim
105 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means to provide two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; wherein said means to provide said datum currents comprise a circuit arrangement with two batteries to supply said two datum currents respectively in the same sense, and means are provided to vary said currents differentially.
Claim 19
Dependent Claim
105 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two coils; means for providing magnetic fields cutting said coils; mechanical means connecting said coils to one another and to said diaphragm; means to provide two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; wherein said means to provide said datum currents comprise a circuit arrangement with two batteries to supply said two datum currents respectively in the same sense, and means are provided to vary said currents differentially.
Claim 20
Dependent Claim
31 words
A transducer according to claim 14, wherein said batteries are connected to said coils through two transistors respectively and means are provided to vary the base currents of said transistors differentially.
Claim 21
Dependent Claim
139 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two coils; means for providing magnetic fields cutting said coils; mechanical meaNs connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils, said magnetic-field providing means, and said mechanical means are surrounded by a hollow body rigidly connected to said coils; and wherein said magnetic fields are provided by pot-magnet means and means for coaxial centering are provided in the form of rubber stockings fixed to the hollow body and during axial movement of the hollow body rolling in the axial direction with sliding seating in the hollow body.
Claim 22
Dependent Claim
139 words
An electrodynamic acoustic transducer with a vibratory diaphragm and centering means for returning said diaphragm to a datum position, said centering means including: two coils; means for providing magnetic fields cutting said coils; mechanical meaNs connecting said coils to one another and to said diaphragm; means for providing two datum currents in said coils respectively to interact with said fields and produce balanced forces thereon solely at said datum position; said coils, said magnetic-field providing means, and said mechanical means are surrounded by a hollow body rigidly connected to said coils; and wherein said magnetic fields are provided by pot-magnet means and means for coaxial centering are provided in the form of rubber stockings fixed to the hollow body and during axial movement of the hollow body rolling in the axial direction with sliding seating in the hollow body.
References Cited (Backward Citations)
GB312950A
Cited
US1895071A
Cited
FR37272E
Cited
US2205365A
Cited
US2727949A
Cited
US3055991A
Cited
US2926221A
Cited
US3196211A
Cited
US3222463A
Cited
US3163723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |