US2038401A - Acoustic diaphragm - Google Patents

Acoustic diaphragm Download PDF

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Publication number
US2038401A
US2038401A US452856A US45285630A US2038401A US 2038401 A US2038401 A US 2038401A US 452856 A US452856 A US 452856A US 45285630 A US45285630 A US 45285630A US 2038401 A US2038401 A US 2038401A
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US
United States
Prior art keywords
diaphragm
coil
conical
disc
centering
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US452856A
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English (en)
Inventor
Norman E Wunderlich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RCA Corp
Original Assignee
RCA Corp
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Filing date
Publication date
Application filed by RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US2038401A publication Critical patent/US2038401A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02—Details
    • H04R9/04—Construction, mounting, or centering of coil
    • H04R9/041—Centering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/16—Mounting or tensioning of diaphragms or cones
    • H04R7/18—Mounting or tensioning of diaphragms or cones at the periphery
    • H04R7/20—Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands

Definitions

  • This invention relates to diaphragms for acoustic instruments and particularly to a coil mounting and centering means for conical diaphragms as found in reproducers of the type known in the art as electrodynamic speakers.
  • the primary object of the invention is to provide an acoustic diaphragmof the character described, which lends itself readily to greater mass production in manufacture, thru the elimination of a plurality of part assembly steps, thereby proportionately reducing the cost of manufacture.
  • the accuracy of the finished product is increased by the further elimination ofvpossible error in positioning and joining a plurality of parts with respect to each other so as to have a common center.
  • a conical acoustic diaphragm is provided with a cylindrical extension or flange for concentrically locating and supporting a diaphragm driving coil structure and a flat flexible disc is provided for supporting and centering the actuated or driven end of said diaphragm, includingthe centering of said coil, with respect to and in co-operative relation with an electro-magnetic field element, said extension and disc forming an integral part of the conical portion comprising the acoustic diaphragm.
  • the invention resides in the novel formation of an acoustic diaphragm so as to include a driving coil supporting means and a flat flexible centering means as an integral part of the diaphragm after the formation thereof from a flat sheet of material. 4
  • Fig. 1 is a sectional view of a frusto-conical diaphragm formed in accordance with the preferred form of the invention and assembled in co-operative relation with a fragmentary portion of a field magnet element therefor.
  • Fig. 2 is a fragmentary sectional plan view of a modified form of the diaphragm centering surface shown in Fig. 1, looking in the direction of the closed end portion of. the conical diaphragm.
  • Fig. 3 is a view similar to Fig. 2, illustrating a further modification.
  • Fig. 4 is a fragmentary sectional view similar in part to Fig. 1, illustrating a further modification wherein the driving coil is wound directly on an integral part of the frusto-conical diaphragm.
  • FIG. 1 an electro-dynamic reproducer or loud speaker of the conventional inner core and outer annular ring magnet type, sufliciently complete for the purpose of this invention, is illustrated in Fig. 1, wherein inner and outer pole pieces ill and l I designate the core and ring pole piece of the field magnet respectively, and which together form an annular magnetic field or air gap as indicated at l2.
  • the core I0 is tap screw threaded at the center of its free end for the reception of a suitable screw or the like l3, whereby, in conjunction with suitable washers N, forms a stationary support for the driven end of the conical diaphragm l5, and an actuating coil structure including a mounting or form IS.
  • the coil structure is centralized on the core II), with respect to and in vco-operative relation with the annular air'gap I2.
  • the opposite or base end of the conical diaphragm I5 is, as usual, mounted over an aperture I! in a baflie plate l8, or on the inner side of the front panel of a cabinet (not shown) by means of a number of arcuate sections 19, for example three, of leather, fabric or the like, having a total 4 length greater than the periphery of the base of the cone.
  • arcuate sections 19 for example three, of leather, fabric or the like, having a total 4 length greater than the periphery of the base of the cone.
  • a diaphragm for a reproducer structure 5 the passage therethru I plated.
  • the diaphragm is given two additional formations other than conicaL-
  • One of these additional formations consists of a cylindrical coil structure locating and supporting cylindrical flange 22 which is formed during the single pressing operation as an integral part of the conical portion comprising the diaphragm l5, and particularly adapted in this the preferred form, for the attachment thereto of the actuating coil mounting l6 by means of a suit-- able adhesive.
  • the other one of said additional formations consists of a small area centrally of the diaphragm which remains flat in the said pressing operation and forms a coil centering flexible disc like element 23 disposed in a plane normal to the axis of the conical diaphragm l5, and within the aforesaid supporting flange 22.
  • the driven end of the conical diaphragm l5 may be attached to the free end of the core ill by means of the screw I 3, it is desirable to form an aperture 24 centrally of the disc like surface 23 of suflicient size to permit of the threaded portion of the screw i3.
  • the said aperture 24 may be blanked out simultaneously with the formation of the conical diaphragm IE, or, it may be formed as a secondary operation after the pressing of the conical diaphragm has been com-
  • the flat flexible and imperforate centering surface 23a is modified by providing a plurality of annular corrugations 25 in the said centering surface, or alternatively as shown in Fig.
  • the surface is perforated by means of a'plurality of openings or holes 26 circumferentially disposed radially of the aperture 24 in the centering surface 23b, whereby a greater degree of flexibility is imparted to the said cen- 1 tering surface between its center point of attachment and the periphery thereof.
  • These modified forms impart a greater freedom of longitudinal or axial movement to the diaphragm without unduly reducing the lateral stiffness of the disc, if this is found necessary or desirable.
  • the flexible centering surface 230 is formed within the cylindrical coil support (see Fig. 4) by telescopically reversing the free end portion of the integral cylindrical extension 220 within itself in the moulding or pressing of the diaphragm ii.
  • the wall of the said free end portion is doubled since the wallthickness thereof will then consist of .two thicknesses of the sheet material used for moulding or pressing a conical diaphragm therefrom. This particular operation incidentally enhances the rigidity of the coil receiving portion of the said free end portion for the coil forming operation as aforesaid.
  • the conical diaphragm is preferably subjected to a moisture proofing treatment such as for example with an aluminum paint or the like, thereby rendering the diaphragm substantially non-hygroscopic.
  • a unitary sound reproducing diaphragm comprising a frusto-conical surface and a cylindrical surface, the smaller base of said conical surface merging into said cylindrical surface, said cylindrical surface having a corrugated centering disc in a plane normal to the axis of said diaphragm.
  • a frusto-conical diaphragm the apex of which merges into a cylinder having a closedend, the closed end being telescopically reversed into the cylindrical portion to provide a centering disc.
  • a sound-producing device comprising in combination, a frusto-conical diaphragm flexibly supported at its large base, an actuating coil secured to the small base of said diaphragm, a cor-' rugated coil-centering diaphragm supporting disc of thin flexible material, and astationary support for a portion of said disc, the corrugated portion of said disc having suflicient radial length 'to movement thereof without unduly reducing -the lateral stiffness of the same.
  • a sound-producing device comprising in combination, a frusto-conical diaphragm flexibly supported at its base, an actuating coil secured to said diaphragm, a coil-centering diaphragm-supporting disc of thin flexible .material provided with concentric corrugations, and a stationary support for a portion of said disc, the corrugated portion of said disc having suflieient radial length to permit of free longitudinal movement thereof without unduly reducing the lateral stiffness of the same,
  • a sound-producing device having a diaphragm flexibly supported at its base and an actuating coil secured thereto, a coil-centering diaphragm-supporting discof thin flexible substantially non-hygroscopic material provided with concentric corrugations, and a stationary support for a portion of said disc, the corrugated portion of said disc having sufiicient' radial'length to permit of free longitudinal movement thereof without unduly reducing the lateral stiffness of the same.
  • a sound-producing device comprising in combination, a cone diaphragm flexibly supported at its base, a magnet having a core and a polepiece, a coil support, an actuating coil carried by said support, said coil being disposed in the air gap between said core and pole-piece and said coil-support being secured to said diaphragm, a thin disc for centering said coil provided with concentric corrugations, said disc being ofthin flexible material and having a portion for receiving said coil support, and a stationary support for another portion of said disc, the corrugated portion of said disc having sufficient radial length to permit of free longitudinal movement thereof without unduly reducing the lateral stiffness of the same.
  • a sound-producing device comprising in I combination, a cone diaphragm. flexibly supported disposed in the air-gap between said core and pole-piece and the corrugated portion of said disc having suflicient radial length to permit of free longitudinal movement thereof without unduly reducing the lateral stiffness of the same.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US452856A 1929-06-20 1930-05-16 Acoustic diaphragm Expired - Lifetime US2038401A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2038401X 1929-06-20

Publications (1)

Publication Number Publication Date
US2038401A true US2038401A (en) 1936-04-21

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ID=10896794

Family Applications (1)

Application Number Title Priority Date Filing Date
US452856A Expired - Lifetime US2038401A (en) 1929-06-20 1930-05-16 Acoustic diaphragm

Country Status (4)

Country Link
US (1) US2038401A (pt)
BE (1) BE369111A (pt)
FR (1) FR692281A (pt)
NL (1) NL28784C (pt)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2609463A (en) * 1948-10-26 1952-09-02 Fauthal A Hassan Electric actuating device
US4933975A (en) * 1988-05-19 1990-06-12 Electro-Voice, Inc. Dynamic loudspeaker for producing high audio power
US6243479B1 (en) 1999-12-08 2001-06-05 Lucio Proni Loudspeaker having pole piece with integral vent bores
US6330340B1 (en) 1995-12-29 2001-12-11 Jl Audio, Inc. Loudspeaker with a diaphragm having integral vent bores
US6535613B1 (en) 1999-12-28 2003-03-18 Jl Audio, Inc. Air flow control device for loudspeaker
US20060191741A1 (en) * 2005-02-25 2006-08-31 Pioneer Corporation Speaker
US20070154056A1 (en) * 2006-01-03 2007-07-05 Jl Audio, Inc. Loudspeaker with air deflector
GB2480058A (en) * 2010-05-04 2011-11-09 Tzu-Chung Chang Inner spider or damper arrangement for a loudspeaker

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3622558A1 (de) * 1986-07-04 1988-01-14 Ant Nachrichtentech Anordnung mit membran fuer einen schallwandler

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2609463A (en) * 1948-10-26 1952-09-02 Fauthal A Hassan Electric actuating device
US4933975A (en) * 1988-05-19 1990-06-12 Electro-Voice, Inc. Dynamic loudspeaker for producing high audio power
US6330340B1 (en) 1995-12-29 2001-12-11 Jl Audio, Inc. Loudspeaker with a diaphragm having integral vent bores
US6243479B1 (en) 1999-12-08 2001-06-05 Lucio Proni Loudspeaker having pole piece with integral vent bores
US6535613B1 (en) 1999-12-28 2003-03-18 Jl Audio, Inc. Air flow control device for loudspeaker
US20060191741A1 (en) * 2005-02-25 2006-08-31 Pioneer Corporation Speaker
US7325650B2 (en) * 2005-02-25 2008-02-05 Pioneer Corporation Speaker
US20070154056A1 (en) * 2006-01-03 2007-07-05 Jl Audio, Inc. Loudspeaker with air deflector
US7715584B2 (en) 2006-01-03 2010-05-11 Jl Audio, Inc. Loudspeaker with air deflector
GB2480058A (en) * 2010-05-04 2011-11-09 Tzu-Chung Chang Inner spider or damper arrangement for a loudspeaker

Also Published As

Publication number Publication date
NL28784C (pt)
FR692281A (fr) 1930-11-04
BE369111A (pt)

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