Patent US3660618A successfully refreshed from Google Patents.
US3660618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic assembly for loudspeaker
Assignee: Individual
•
Filing: 1970-10-01
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Granted: 1972-05-02
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Expires: 1990-10-01
Abstract
Abstract A loudspeaker having a cup-shaped outer pole piece and an inner pole piece which is telescoped within it and separated from it both axially and radially to provide a cup-shaped space between the two. In the space and in intimate contact with the opposed surfaces of the pole pieces is a cup-shaped insert of permanently magnetic material in the form of magnetic particles suspended in an inert binder. The inert binder is preferably formed of elastomeric material such as synthetic rubber or resilient plastic with a snug or slightly interfering fit so that the elements may simply be pressed together to assemble them. The permanently magnetic material is magnetized during fabrication, prior to, or following, assembly, being polarized so that the surfaces presented to the two pole pieces are of opposite polarity. The invention resides in part in the method used in assembling the parts together. In an aspect of the invention the magnetic insert is of composite construction using adjacent portions of magnetic material polarized at right angles. In another aspect of the invention the insert includes an annulus which is formed of a bar of elastomeric material bent in a circular shape incident to assembly.
Inventors
- 👤 Stanley F White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:17
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/025; H04R2209/00; H04R2209/022; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
160 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole pole piece being nested in the outer to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the cups toward the edge of the other to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereon define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic material having surfaces in intimate contact with the opposed surfaces of the pole pieces to form a magnetic circuit of low reluctance for concentration of flux in the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 2
Dependent Claim
160 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole pole piece being nested in the outer to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the cups toward the edge of the other to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereon define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic material having surfaces in intimate contact with the opposed surfaces of the pole pieces to form a magnetic circuit of low reluctance for concentration of flux in the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 3
Dependent Claim
155 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece formed of steel and nested in the outer pole piece to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the pole pieces toward the edge of the other to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereof define a cup-shaped space between them, and a molded cup-shaped insert of permanently magnetic material having intimate surface contact with the opposed surfaces of the pole pieces so as to define a magnetic circuit of low reluctance for concentration of flux in the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 4
Dependent Claim
155 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece formed of steel and nested in the outer pole piece to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the pole pieces toward the edge of the other to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereof define a cup-shaped space between them, and a molded cup-shaped insert of permanently magnetic material having intimate surface contact with the opposed surfaces of the pole pieces so as to define a magnetic circuit of low reluctance for concentration of flux in the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 5
Dependent Claim
37 words
The combination as claimed in claim 2 in which the insert is in the form of permanently magnetic particles suspended in a body of inert elastomeric material dimensioned to fit the opposed surfaces of the pole pieces.
Claim 6
Dependent Claim
52 words
The combination as claimed in claim 3 in which the insert is dimensioned slightly oversize to provide a press fit with the opposed surfaces of the pole pieces for development of internal pressure in the insert so that the insert is self-accommodating to any geometric or surface irregularities of the opposed surfaces.
Claim 7
Dependent Claim
28 words
The combination as claimed in claim 2 in which the wall of the cup-shaped insert has a thickness which is greater than the bottom of the cup-shaped insert.
Claim 8
Dependent Claim
24 words
The combination as claimed in claim 2 in which the wall thickness of the insert increases progressively in the direction of the air gap.
Claim 9
Dependent Claim
16 words
The combination as claimed in claim 2 in which the molded insert is molded in situ.
Claim 10
Dependent Claim
30 words
The combination as claimed in claim 2 in which a basket is provided formed integrally with the cup-shaped outer pole piece as an extension of the edge of the cup.
Claim 11
Independent Claim
114 words
The method of forming a loudspeaker magnetic assembly, having an outer cup-shaped pole piece and an inner pole piece dimensioned to provide an annular space between them, which comprises the steps of separately forming an insert consisting of particles of permanently magnetic material suspended in a body of inert elastomeric material of annular shape in which the radial thickness is slightly greater than the radial dimension of the annular space, and then telescoping the insert and pole pieces into assembled relation with a press fit so that the insert develops internal pressure to insure accommodating itself to geometric or surface irregularities of the pole pieces thereby to achieve minimum reluctance at the contacting surfaces.
Claim 12
Independent Claim
114 words
The method of forming a loudspeaker magnetic assembly, having an outer cup-shaped pole piece and an inner pole piece dimensioned to provide an annular space between them, which comprises the steps of separately forming an insert consisting of particles of permanently magnetic material suspended in a body of inert elastomeric material of annular shape in which the radial thickness is slightly greater than the radial dimension of the annular space, and then telescoping the insert and pole pieces into assembled relation with a press fit so that the insert develops internal pressure to insure accommodating itself to geometric or surface irregularities of the pole pieces thereby to achieve minimum reluctance at the contacting surfaces.
Claim 13
Dependent Claim
44 words
The method covered in claim 9 which includes the additional steps of applying magnetic charging flux to the pole pieces for charging the insert and then telescoping into the outer pole piece a collar of permeable material to define a narrow annular air gap.
Claim 14
Independent Claim
144 words
The method of making a loudspeaker magnetic assembly having cup-shaped inner ad outer pole pieces providing opposed edges to define an air gap and with the inner pole piece being smaller than the outer both radially and axially, which comprises molding a cup-shaped insert formed of permanently magnetic particles suspended in a body of inert elastomeric material with the insert having a bottom which conforms to the opposed end surfaces of the pole pieces and a side wall which conforms to the opposed wall surfaces of the pole pieces but with the side wall being radially thicker than the radial spacing between the opposed wall surfaces, and telescoping the pole pieces and insert together with a press fit to the point of bottoming thereby to insure intimate all over contact between the surfaces of the insert and the opposed surfaces of the pole pieces.
Claim 15
Independent Claim
144 words
The method of making a loudspeaker magnetic assembly having cup-shaped inner ad outer pole pieces providing opposed edges to define an air gap and with the inner pole piece being smaller than the outer both radially and axially, which comprises molding a cup-shaped insert formed of permanently magnetic particles suspended in a body of inert elastomeric material with the insert having a bottom which conforms to the opposed end surfaces of the pole pieces and a side wall which conforms to the opposed wall surfaces of the pole pieces but with the side wall being radially thicker than the radial spacing between the opposed wall surfaces, and telescoping the pole pieces and insert together with a press fit to the point of bottoming thereby to insure intimate all over contact between the surfaces of the insert and the opposed surfaces of the pole pieces.
Claim 16
Independent Claim
169 words
The method of making a loudspeaker magnetic assembly using a cup-shaped inner and outer pole pieces providing opposed edges to define an air gap and with the inner pole pieces being smaller than the outer both radially and axially, which comprises forming a molten mass of material made up of permanently magnetic particles suspended in an inert hardenable binder, temporarily fixing the inner pole piece in a position telescoped within the outer pole piece but with the bottom and side walls spaced therefrom to form a cup-shaped space between them, pouring the molten material into the cup-shaped space to form a magnetic insert and permitting the same to harden in situ to secure the pole pieces mechanically to one another, and applying magnetism between the pole pieces incident to hardening for polarization of the permanentLy magnetic particles with the insert having one plurality at the surface which mates with one of the pole pieces and having the opposite plurality at the surface which mates with the other pole piece.
Claim 17
Independent Claim
169 words
The method of making a loudspeaker magnetic assembly using a cup-shaped inner and outer pole pieces providing opposed edges to define an air gap and with the inner pole pieces being smaller than the outer both radially and axially, which comprises forming a molten mass of material made up of permanently magnetic particles suspended in an inert hardenable binder, temporarily fixing the inner pole piece in a position telescoped within the outer pole piece but with the bottom and side walls spaced therefrom to form a cup-shaped space between them, pouring the molten material into the cup-shaped space to form a magnetic insert and permitting the same to harden in situ to secure the pole pieces mechanically to one another, and applying magnetism between the pole pieces incident to hardening for polarization of the permanentLy magnetic particles with the insert having one plurality at the surface which mates with one of the pole pieces and having the opposite plurality at the surface which mates with the other pole piece.
Claim 18
Dependent Claim
51 words
The method as claimed in claim 12 which includes the step of inserting between the presented edges of the pole pieces an annular ring of permeable material dimensioned to have a press fit with one of the pole pieces and to define an annular air gap with respect to the other.
Claim 19
Dependent Claim
160 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer to provide opposed edges radially spaced from one another and being smaller than the outer pole piece both axially and radially so as to define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic particles in an inert binder occupying the space and in intimate contact with the opposed surfaces of the pole pieces, the insert being so magnetized that the surfaces thereof which contact the respective surfaces of the pole pieces are of opposite polarity, and an annular ring of permeable material having a press fit with the edge of one of the pole pieces and extending radially into the vicinity of the other to define an annular air gap for receiving a voice coil.
Claim 20
Dependent Claim
160 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer to provide opposed edges radially spaced from one another and being smaller than the outer pole piece both axially and radially so as to define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic particles in an inert binder occupying the space and in intimate contact with the opposed surfaces of the pole pieces, the insert being so magnetized that the surfaces thereof which contact the respective surfaces of the pole pieces are of opposite polarity, and an annular ring of permeable material having a press fit with the edge of one of the pole pieces and extending radially into the vicinity of the other to define an annular air gap for receiving a voice coil.
Claim 21
Dependent Claim
21 words
The combination as claimed in claim 14 in which the ring has an integral axially extending portion adjacent the air gap.
Claim 22
Dependent Claim
145 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, presenting an inwardly-facing edge, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer and shorter in length, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic material having surfaces of opposite plurality in intimate contact with the respective opposed surfaces of the pole pieces, said inner pole piece having an extension of cylindrical shape telescoped within it and extending axially therefrom to present an edge which is opposite the edge of the outer pole piece to define an annular air gap with the latter for reception of a voice coil.
Claim 23
Dependent Claim
145 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, presenting an inwardly-facing edge, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer and shorter in length, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces define a cup-shaped space between them, a molded cup-shaped insert of permanently magnetic material having surfaces of opposite plurality in intimate contact with the respective opposed surfaces of the pole pieces, said inner pole piece having an extension of cylindrical shape telescoped within it and extending axially therefrom to present an edge which is opposite the edge of the outer pole piece to define an annular air gap with the latter for reception of a voice coil.
Claim 24
Dependent Claim
154 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of cylindrical shape also of steel and having a diameter and axial length which is less than the outer pole piece so that when the inner pole piece is telescoped into the outer one to provide an annular air gap, there is defined, between the pole pieces, an end space and an annular wall space, a disk of permanently magnetic material dimensioned to substantially occupy the end space, an annulus of permanently magnetic material dimensioned to occupy the wall space, the annulus being formed of permanently magnetic particles suspended in a body of elastomeric material and dimensioned to provide a press fit into the annular wall space for not only accommodating geometric surface irregularities but for holding the inner pole piece in intimate axial engagement with respect to the disk.
Claim 25
Dependent Claim
154 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of cylindrical shape also of steel and having a diameter and axial length which is less than the outer pole piece so that when the inner pole piece is telescoped into the outer one to provide an annular air gap, there is defined, between the pole pieces, an end space and an annular wall space, a disk of permanently magnetic material dimensioned to substantially occupy the end space, an annulus of permanently magnetic material dimensioned to occupy the wall space, the annulus being formed of permanently magnetic particles suspended in a body of elastomeric material and dimensioned to provide a press fit into the annular wall space for not only accommodating geometric surface irregularities but for holding the inner pole piece in intimate axial engagement with respect to the disk.
Claim 26
Dependent Claim
34 words
The combination as claimed in claim 17 in which the annulus of permanently magnetic material is polarized in the radial direction and the disc of permanently magnetic material is polarized in the axial direction.
Claim 27
Dependent Claim
58 words
The combination as claimed in claim 17 in which the annulus of permanently magnetic material extends the axial depth of the outer pole piece and in which the disc of permanently magnetic material has an area which corresponds to the area of the inner pole piece and a thickness which corresponds to the thickness of the end space.
Claim 28
Dependent Claim
164 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cUp shape formed of sheet steel, an inner pole piece formed of steel and nested in the outer pole piece to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the pole pieces toward the edge of the other to provide radial air gap for a voice coil, the outer pole piece being of frusto-conical shape, the inner pole piece being of substantially cylindrical shape and spaced from the outer axially as well as radially to form an interspace, and a molded cup-shaped insert of permanently magnetic material having a wall of flaring cross section in intimate surface contact with the opposed surfaces of the pole pieces and with the portion of greatest cross section being in the region of the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 29
Dependent Claim
164 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cUp shape formed of sheet steel, an inner pole piece formed of steel and nested in the outer pole piece to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of at least one of the pole pieces toward the edge of the other to provide radial air gap for a voice coil, the outer pole piece being of frusto-conical shape, the inner pole piece being of substantially cylindrical shape and spaced from the outer axially as well as radially to form an interspace, and a molded cup-shaped insert of permanently magnetic material having a wall of flaring cross section in intimate surface contact with the opposed surfaces of the pole pieces and with the portion of greatest cross section being in the region of the air gap, the inner and outer surfaces of the insert being permanently magnetized with opposite polarity.
Claim 30
Dependent Claim
188 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape having a generally flat bottom wall and a side wall terminating in an edge and formed of sheet steel, a hollow inner pole piece having a cylindrical portion terminating in an edge, the inner pole piece being nested in the outer pole piece so that the edges are opposed and radially spaced from one another, the inner pole piece having a generally flat bottom wall portion parallel to the bottom and spaced therefrom, the outer pole piece having an annular ring of permeable material offering a press fit with the edge of the outer pole piece and extending radially inward toward the edge of the inner pole piece to define an annular air gap for receiving a voice coil, a molded insert of permanently magnetic particles in an inert binder substantially occupying the space between the pole pieces and in intimate contact with the opposed surfaces of the pole pieces, the insert being so magnetized that the surfaces thereof which contact the respective surfaces of the pole pieces are of opposite polarity.
Claim 31
Dependent Claim
188 words
In a loudspeaker magnetic assembly, the combination comprising an outer pole piece of hollow cup shape having a generally flat bottom wall and a side wall terminating in an edge and formed of sheet steel, a hollow inner pole piece having a cylindrical portion terminating in an edge, the inner pole piece being nested in the outer pole piece so that the edges are opposed and radially spaced from one another, the inner pole piece having a generally flat bottom wall portion parallel to the bottom and spaced therefrom, the outer pole piece having an annular ring of permeable material offering a press fit with the edge of the outer pole piece and extending radially inward toward the edge of the inner pole piece to define an annular air gap for receiving a voice coil, a molded insert of permanently magnetic particles in an inert binder substantially occupying the space between the pole pieces and in intimate contact with the opposed surfaces of the pole pieces, the insert being so magnetized that the surfaces thereof which contact the respective surfaces of the pole pieces are of opposite polarity.
Claim 32
Independent Claim
119 words
The method of forming a loudspeaker magnetic assembly having an outer cup-shaped pole piece and an inner pole piece defining an air gap and dimensioned to provide an annular space between them which comprises the steps of separately forming an insert of straight bar shape consisting of particles of permanently magnetic material suspended in a body of inert elastomeric material, applying flux to the insert along its thickness dimension, to permanently magnetize the same, bending the insert into circular shape to form an annulus which is magnetically polarized in the radial direction, and then inserting the annulus between the outer and inner pole pieces in face to face contact therewith so that flux is produced in the air gap.
Claim 33
Independent Claim
119 words
The method of forming a loudspeaker magnetic assembly having an outer cup-shaped pole piece and an inner pole piece defining an air gap and dimensioned to provide an annular space between them which comprises the steps of separately forming an insert of straight bar shape consisting of particles of permanently magnetic material suspended in a body of inert elastomeric material, applying flux to the insert along its thickness dimension, to permanently magnetize the same, bending the insert into circular shape to form an annulus which is magnetically polarized in the radial direction, and then inserting the annulus between the outer and inner pole pieces in face to face contact therewith so that flux is produced in the air gap.
Claim 34
Independent Claim
149 words
The method of forming a loud speaker assembly having an outer pole piece and an inner pole piece shaped to define an annular space between them which comprises the steps of telescoping between the pole pieces an annular insert consisting of particles of permanently magnetic material suspended in a body of elert elastomeric material having a radial thickness which is slightly less than the radial space between the pole pieces to permit easy insertion, applying axial squeezing force to the end surfaces of the magnetic insert to cause the insert to be shortened in axial dimension and to swell in radial thickness into intimate contact with the presented annular surfaces of the pole pieces and with the insert accommodating itself to any minor geometric or surface irregularities of the pole pieces, and then blocking the end surfaces in the squeezed position to maintain the insert under constant volumetric compression.
Claim 35
Independent Claim
149 words
The method of forming a loud speaker assembly having an outer pole piece and an inner pole piece shaped to define an annular space between them which comprises the steps of telescoping between the pole pieces an annular insert consisting of particles of permanently magnetic material suspended in a body of elert elastomeric material having a radial thickness which is slightly less than the radial space between the pole pieces to permit easy insertion, applying axial squeezing force to the end surfaces of the magnetic insert to cause the insert to be shortened in axial dimension and to swell in radial thickness into intimate contact with the presented annular surfaces of the pole pieces and with the insert accommodating itself to any minor geometric or surface irregularities of the pole pieces, and then blocking the end surfaces in the squeezed position to maintain the insert under constant volumetric compression.
Claim 36
Dependent Claim
222 words
In a loud speaker assembly the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of the outer pole piece to A position spaced from the edge of the inner pole piece to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereon with the collar seated in position define an annular space between them having a predetermined axial length and radial thickness, the annular space being occupied by an annular magnetic insert of elastomeric material having a normal radial thickness which is slightly less than the thickness of the space and having a normal axial length which is slightly greater than the length of the space, said collar having a press fit with the outer pole piece so that when the collar is pressed into seated position axial force is applied to the end surfaces of the insert causing the insert to swell radially into intimate contact with the presented faces of the inner and outer pole pieces.
Claim 37
Dependent Claim
222 words
In a loud speaker assembly the combination comprising an outer pole piece of hollow cup shape formed of sheet steel, an inner pole piece of hollow cup shape formed of sheet steel, the inner pole piece being nested in the outer to provide opposed edges radially spaced from one another, an annular steel collar radially extending from the edge of the outer pole piece to A position spaced from the edge of the inner pole piece to provide a radial air gap for a voice coil, the inner pole piece being spaced from the outer axially as well as radially so that the opposed surfaces thereon with the collar seated in position define an annular space between them having a predetermined axial length and radial thickness, the annular space being occupied by an annular magnetic insert of elastomeric material having a normal radial thickness which is slightly less than the thickness of the space and having a normal axial length which is slightly greater than the length of the space, said collar having a press fit with the outer pole piece so that when the collar is pressed into seated position axial force is applied to the end surfaces of the insert causing the insert to swell radially into intimate contact with the presented faces of the inner and outer pole pieces.
Claim 38
Dependent Claim
52 words
The combination as claimed in claim 24 in which an inert non-compressible spacer is interposed between the collar and the presented end surface of the insert for transmitting compressive force from the collar to the insert, the spacer being of annular shape conforming substantially to the end surface of the magnetic insert.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |