US3801943A - Electoacoustic transducers and electromagnetic assembly therefor - Google Patents

Electoacoustic transducers and electromagnetic assembly therefor Download PDF

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Publication number
US3801943A
US3801943A US00259378A US25937872A US3801943A US 3801943 A US3801943 A US 3801943A US 00259378 A US00259378 A US 00259378A US 25937872 A US25937872 A US 25937872A US 3801943 A US3801943 A US 3801943A
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United States
Prior art keywords
coil holder
cap
diaphragm
coil
electroacoustic transducer
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Expired - Lifetime
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US00259378A
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English (en)
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J Bertagni
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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
    • H04R9/06—Loudspeakers
    • H04R9/066—Loudspeakers using the principle of inertia
    • 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
    • H04R9/022—Cooling arrangements

Definitions

  • An electroacoustic transducer comprising a diaphragm and an electromagnetic assembly in driving relationship with the diaphragm, the assembly comprising a magnet, a core defining a gap in the magnet, a coil supported by a coil holder movably arranged in the gap with an end portion facing the diaphragm, a cap on said end portion having a'top surface directed toward, and in driving relationship with, the diaphragm, the surface being preferably secured to the diaphragm by means of an adhesive.
  • the adhesive may be soft or hard and the diaphragm is preferably flat.
  • the cap seals the coil holder and a perforation is I provided connecting the space formed between the 179]! BS cap, coil holder, core and gap with another surrounding whereby a rectilinear to and fro movement pump is defined by the cap, coil holder and core, the pumping action moving air to cool the coil.
  • the lower end of the coil holder has a flange to prevent the coil from being shock-removed from the coil holder, and the upper end of the holder has a flange which 56 w 4 1 flw Apr.
  • the present invention relates to an electromagnetic assembly for electroacoustic transducers and the like, and more particularly it refers to an electromagnetic assembly, as well as an electroacoustic transducer utilizing said assembly, which include, due to its structural and constitutive arrangement, a number of particular features, each of which may be used alone or in combination to achieve different effects and results.
  • one of the features is to use the vibratory movement of the coil holder to act as a plunger of a to and fro moving pump in order to cool or refrigerate the core of the magnet, i.e. the pole piece of the magnet, the gap, the
  • the electromagnetic assembly of the present invention may also be used below the water, for example in connection with loudspeakers and microphones. As to the aspect of using the electromagnetic assembly under the water, said assembly may be combined with vibratory panels for other purposes, such asfor a washing machine. It is also possible to use the electromagnetic assembly in connection with vibratory panels to transmit such vibrations to granular materials arranged on said vibratory panel.
  • the electromagnetic assembly of the present invention is applicable to various types of electroacoustic transducers usable in a number of different fields within industry, the assembly being in driving relationship with the diaphragm of the transducer.
  • the diaphragm can drive'the electromagnetic assembly or the electromagnetic assembly can drive the diaphragm.
  • the acoustic vibrations may be those which can be or are to be heard (e.g., music, speech, etc.), or those whose purpose is mere vibration (e.g., washing machine).
  • Another feature of the invention is the use of a cap on the coil holder as the surface for transmitting the vibrations 'between'the coil holder and the diaphragm.
  • the known electromagnetic assemblies for electroacoustic transducers, and particularly for loud speakers have to face the well known problem of the generation of excessive heat within the zone ofthe gap and therefore, it is an important feature of the invention to be able to refrigerate said zone, whereby the usual life of the electromagnetic assembly is undoubtedly increased, or in other words, the life of the driving unit of the loudspeakers is increased.
  • the electromagnetic assembly is used for flat loudspeakers, it is an aim that the vibrations be more energetic and therefore the amount of heat which is generated is still larger.
  • a good refrigeration within the air gap zone is even more important when the electromagnetic assembly is used in relationship with flat loudspeakers.
  • Still another feature which fonns part of the present invention is related to the output of the loudspeakers. It is well known that in the known loudspeakers the impedance is substantially constant in the zone of low frequencies Hz to 5,000 Hz) and thereafter a weak growing tendency'up to the region of 20 KHz (20,000 cycles) can be seen. In the known loudspeakers there is at least one low frequency peak.
  • the present invention utilizes an electromagnetic assembly for electroacoustic transducers and the like, comprising a magnet, a core defining a gap in said magnet, a coil holder, a coil wound on said coil holder movably arranged in said gap and an end portion of said coil holder projecting out of said magnet, wherein the coil holder is provided with a seal cap in the portion projecting out of said gap, 21 space being formed between said cap, coil holder, core and gap, at least one perforation connecting said space with another surrounding, thus a rectiliner to and fro moving pump being defined between said cap, coil holder and core.
  • the electromagnetic assembly may further comprise a resilient spider, mounted on the magnetic assembly and linked to said end portion of said coil holder.
  • the resilient spider or support may be an impermeable and sealing diaphragm.
  • the perforation mentioned in the above paragraphs which connects said space with said other surrounding may be a through perforation in the core, so that one of the ends of said perforation faces said cap.
  • the air mass which is conveyed by the coil holder with its cap through the perforation may act as a cooling means for the core, the gap, the coil holder and the coil, but it may also act as a resilient cushion, specially when the electromagnetic assembly is used under water, where no refrigeration is necessary; in this event the other end of said perforation is sealed.
  • FIG. 1 is a perspective view of an electromagnetic assembly for electroacoustic transducers and the like, according to the present invention.
  • FIG. 2 shows in perspective view a detail of a portion of the flat diaphragm in the zone where it is to be linked to the electromagnetic assembly of FIG. 1.
  • FIG. 4 is a longitudinal section of the electromagnetic assembly applied to a flat diaphragm of a flat loudspeaker.
  • FIG. 5 is a detail in longitudinal section, similar to FIG. 4, but showing a possible alternative embodiment in relationship to the pumping system.
  • FIG. 6 is a detail in longitudinal section, similar to FIG. 4, but showing another possible alternative embodiment in relationship to the pumping system.
  • FIG. 7 is a detail in longitudinal section of the coil holder, coil and resilient support.
  • FIG. 8 is a detail in longitudinal section, similar to FIG. 4, but showing another possible alternative embodiment in relationship to the pumping system.
  • the electromagnetic assembly 1 of the present invention comprises a magnet 2 which is a cylinder of small height and has a central cylindrical through hole 3.
  • the height of the core.6 is such, when the three members 2, 5 and 9 are assembled, that the upper base 6 of the core 6 is flush with the upper face 25 of the second disc 9 (FIG. 4).
  • Gap 11 houses the coilholder '12.
  • the coil holder 12 will perform a rectilinear alternative or to and fro movement, which is substantially coaxial with the longitudinal axis of the assembly.
  • the coilholder 12 is in one of the possible embodiments, a paper made cylinder 13, the inside face of which is sheathed with a metal sheet 14, for instance an aluminum foil.
  • the coil holder 12 need not be an endless cylinder, but have a longitudinal cut so as to define a longitudinal slot, as is known in the art, it is preferred to make the coil holder as an endless cylinder.
  • a coil 15 is wound which covers the lower half, leaving free the upper half, which defines the end .portion which projects out of the gap 11.
  • the coil for instance by means of two layers of turns, of which the inner layer of turns 16 (FIG. 7) is so wound as to progressively decrease the space between turns from bottom to top, while the outer layer of turns 17 is wound so as to progressively decrease the space between turns from top to bottom, whereby an optimum turn density is achieved to fulfil the purpose.
  • the upper flange 19 is provided, in order to increase the binding surface which links the upper end 19 with the resilient support which is a kind of a diaphragm 20.
  • this diaphragm or resilient support 20, also called spider is generally made of an impregnated porous fabric to convey the necessary resiliency and yet rigidity and such known spider may be used in connection with the present invention; however, it is also possible to replace said fabric spider by an air impermeable member, such as of neoprene rubber.
  • the diaphragm 20 has an edge 21 defining the larger base portion, from which rises a frustoconical portion 22, the smaller. base portion 23 of which is provided with concentric ondulations ending in a connecting edge 24 which is connected by means of an adhesive (not shown) to the upper end or flange 19 of the coil holder 12 (FIG. 7).
  • the edge 21 is connected to the upper face 25 (FIG. 1) of the second disc 9 of the magnet assembly comprised by disc 5, magnet 2, and disc 9.
  • the smaller base portion 23 of diaphragm 20 provides the necessary resiliency to allow for the to and fro movement of the coil holder 12.
  • the upper flange 19 of the coil holder 12 satisfies also another purpose, namely to increase the supporting surface for the cap 26 made of an insulating material, which is preferably soft, and which, for example, may be made of polyethylene or polyurethane.
  • This cap 26 has a lower cylindrical porjection 27 which enters the coil holder 12 and is sealed thereto at the same time as the main disc-shaped body 28, of larger diameter than the lower cylindrical projection 27, overlaps the upper flange l9'of the coil holder 12.
  • the body 28 and flange 19 thus define additional sealing surfaces.
  • cap 26 is connected to the coil holder 12 by an adhesive (not shown).
  • junction between lower cylindrical projection 27 and the main disc shaped body 28 defines a flange receiving portion which includes surfaces generally transverse and parallel to the axis of the coil holder, and this portion receives the flange 19 with the adhesive (not shown) being interposed between the opposed surfaces of the holder and the cap.
  • the upper face of the upper I disc-shaped body 28 has two parallel channels 29, 29'.
  • Diaphragm 34 corresponds to a flat loudspeaker having a front face 35 and a rear face 36. This rear face 36 has a circular recess 37, from which extends a pair of parallel channels 38, 38.
  • the circular recess 37 is filled with an adhesive (not shown) and the cap 26 is glued through its top face 26 thereto so that the portion of theconductors 31, 31 and the insulated conductors 32, 32' projecting away from cap 26 become housed in the channels 38, 38, thus building a homogeneous assembly and further reducing the possibility of breakage of the conductors.
  • conductors 32, 32 are furthermore connected, as already stated, to a pertinent electronic circuit (not shown).
  • the adhesive may be a hard adhesive, or in other words it produces a rigid connection between the recess 37 and the top 26'. It is also possible to use a soft adhesive, such as a resilient adhesive, whereby the intermodulation is improved.
  • the cap is a member independent of the diaphragm and defines a large contact top surface directed towards the diaphragm and in driving relationship with the diaphragm, so that, when used as a microphone, for example, the diaphragm drives the cap through said surface, and when used as a speaker, for example, the cap drives the diaphragm through said surface.
  • perforation 7 of FIG. 4 it would also be possible to replace perforation 7 of FIG. 4 by perforations 7'(FIG. 8) which are present in the first disc 5 surrounding the core 6, so that the movement of refrigerating or cooling air is performed through the gap 11. i
  • the assembly can likewise operate in a satisfactory manner.
  • perforation 7 is sealed (FIG. 5) by means of a plug rod 39.
  • the position of rod 39 is gauged with regard to perforation 7 in order to achieve good operation. In this event, no resilient spider suspension of the type of diaphragm 20 is necessary since the air cushion can carry out this role, but upon using the electromagnetic assembly under water, sealing means must be provided in order to avoid that the water enters the gap 11.
  • valve 41 for gauging a crosssectional passage for the air, so that an optimum relationship can be achieved.
  • valve 41 may be replaced by a tubular member with a pre-established cross-sectional area for the air passage.
  • a further modification is shown which as such is applicable to any of the other structural embodiments.
  • the electromagnetic assembly of the present invention When the electromagnetic assembly of the present invention is used with a loudspeaker, for instance of the flat type as described in relationship to FIG. 2, it may be that special effects are intended to be achieved, such as an increased range of low frequencies. In other words, in a musical piece it may be desired that the human voice becomes submerged within the musical poem. To achieve this effect in the cap 26, and more particularly in the lower projection 27 a recess 42 may be made to house therein a weight member 43. Thus, the mass of the movable assembly and more particularly of the cap 26 and coil holder 12' with its coil 15 is increased, whereby the assembly will operate within a larger range of low frequencies.
  • the coil holder 12 described in relationship with FIG. 7 has a relatively low mechanical resistance and it may be convenient that such resistance is increased.
  • the coil holder 12 may for instance be made of plastified (bakelized) cardboard, whereby a larger resistance against impacts is achieved upon the coil holder entering in impacting contact with the first disc 5.
  • a coil holder so made has i the drawback .that it is inefficiently cooled, but this drawback can be compensated by producing the weight member 43 of a good electricity and heat conducting material, such as copper, and since said copper disc or plate 43 faces the mass of air which is pumped through the perforation 7, the copper disc transfers the heat which it absorbs to the cooling air mass.
  • a heat insulating layer 44 (FIG. 6) is arranged between the metal disc 43 and said cap 26.
  • cap 26 is made of expanded, bonded, cellular plastics, such as polystyrene, it may become advisable to arrange a heat insulating mass between the plate 43 and the recess 42, such as an asbestos disc-member (not shown) to avoid that the cap 26 becomes injured by heat.
  • a heat insulating mass between the plate 43 and the recess 42, such as an asbestos disc-member (not shown) to avoid that the cap 26 becomes injured by heat.
  • cap 26 Another possibility would be to manufacture the cap 26 from a rigid plastic, such as nylon.
  • An electroacoustic transducer comprising a diaphragm and an electromagnetic assembly in driving relationship with said diaphragm, said electromagnetic assembly comprising a magnet, a core defining a gap in said magnet, a coil supported by a coil holder movably arranged in said gap with an end portion of said coil holder facing said diaphragm, an independent cap on 32.
  • An electromagnetic assembly for electroacoustic transducers and the like comprising a magnet, a core defining a gap in said magnet, a coil holder having a coil wound thereon, said coil holder being movably arranged in said gap and an end portion of said coil holder projecting out of said magnet, said coil holder being provided with a seal cap in the portion projecting out of said gap, a space being formed between said cap, coil holder, core and gap, at least one perforation connecting said space with another surrounding, whereby a rectilinear to and fro moving pump is defined by said cap, coil holder and core, said coil holder being an endless cylinder the outer face of which is of electricity insulating material and the inner face of which is sheathed with an electricity conducting layer.
  • An electromagnetic assembly for electroacoustic transducers and the like comprising a magnet, a core defining a gap in said magnet, a coil holder having a coil wound thereon, said coil holder being movably arranged in said gap and an end portion of said coil holder projecting out of said magnet, said coil holder being provided with a seal cap in the portion projecting out of said gap, a space being formed between said cap, coil holder, core and gap, at least one perforation connecting said space with another surrounding, whereby a rectilinear to and fro moving pump is defined by said cap, coil holder and core, said cap having an upper face remote from said coil holder, said cap being provided on its upper face with a pair of channel members in which respective end portions of the conductor of the coil are housed and connected to respective other conductors.
  • An electromagnetic assembly for electroacoustic transducers and the like comprising a magnet, a core defining a gap in said magnet, a coil holder having a coil wound thereon, said coil holder being movably arranged in said gap and an end portion of said coil holder projecting out of said magnet, said coil holder being provided with a seal cap in the portion projecting out of said gap, a space being formed between said cap, coil holder, core and gap, at least one perforation connecting said space with another surrounding, whereby a rectilinear to and fro moving pump is defined by said cap, coil holder and core, said core holder being made of plastified cardboard and said cap housing a good heat and electricity conducting metal disc facing said space.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US00259378A 1971-06-16 1972-06-05 Electoacoustic transducers and electromagnetic assembly therefor Expired - Lifetime US3801943A (en)

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AR23622071 1971-06-16

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US3801943A true US3801943A (en) 1974-04-02

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US (1) US3801943A (de)
JP (1) JPS5514600B1 (de)
DE (1) DE2229239A1 (de)
DK (1) DK137820B (de)
FR (1) FR2141983B3 (de)
NL (1) NL7208047A (de)

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4013846A (en) * 1975-08-28 1977-03-22 Minnesota Mining And Manufacturing Company Piston loudspeaker
US4257325A (en) * 1978-04-05 1981-03-24 Bertagni Jose J Mouting of a substantially planar diaphragm defining a sound transducer
US4384174A (en) * 1979-10-02 1983-05-17 Victor Company Of Japan, Limited Moving voice coil loudspeaker, peripheral diaphragm support, diaphragm construction, bobbin to diaphragm reinforcement
EP0139302A2 (de) * 1983-10-19 1985-05-02 Sanden Corporation Elektromechanischer Vibrator im Audio-Frequenz-Bereich
US4928312A (en) * 1988-10-17 1990-05-22 Amel Hill Acoustic transducer
US4997058A (en) * 1989-10-02 1991-03-05 Bertagni Jose J Sound transducer
US5425107A (en) * 1992-04-09 1995-06-13 Bertagni Electronic Sound Transducers, International Corporation Planar-type loudspeaker with dual density diaphragm
WO1997009859A1 (en) * 1995-09-02 1997-03-13 New Transducers Limited Inertial vibration transducers
US5693917A (en) * 1993-11-18 1997-12-02 Sound Advance Systems, Inc. Planar diaphragm loudspeaker
WO1998034320A2 (en) * 1997-01-31 1998-08-06 New Transducers Limited Electro-dynamic inertial vibration exciter
WO1999002012A1 (en) * 1997-07-03 1999-01-14 New Transducers Limited Panel-form loudspeakers
US5991424A (en) * 1995-04-28 1999-11-23 Sound Advance Systems, Inc. Planar diaphragm speaker with heat dissipator
WO1999060820A1 (de) * 1998-05-15 1999-11-25 Harman Audio Electronic Systems Gmbh Treiber für flaches klangpaneel
US6343136B2 (en) * 1997-03-25 2002-01-29 Pioneer Electronic Corporation Speaker apparatus and manufacturing method thereof
US20030031324A1 (en) * 2001-08-07 2003-02-13 Richard Lukacovic Solenoid for an electrolarynx
US6574347B1 (en) * 2000-11-17 2003-06-03 Logitech Europe S.A. Flat-panel loudspeaker with compressed dampeners
US6618487B1 (en) 1996-09-03 2003-09-09 New Transducers Limited Electro-dynamic exciter
US20040037446A1 (en) * 2001-07-19 2004-02-26 Akinori Hasegawa Speaker and method of manufacturing the speaker
US20040056829A1 (en) * 2002-02-06 2004-03-25 Libby James B. Automated multi-task window assembly
US6751333B1 (en) 1995-09-02 2004-06-15 New Transducers Limited Inertial vibration transducers
US20040129492A1 (en) * 2002-10-28 2004-07-08 Alejandro Bertagni Planar diaphragm loudspeaker and related methods
US20040211310A1 (en) * 2003-04-25 2004-10-28 Takashi Hagiwara Sound pickup device for percussion instrument
US6904154B2 (en) 1995-09-02 2005-06-07 New Transducers Limited Acoustic device
US7109959B2 (en) 2002-02-06 2006-09-19 Andersen Corporation Multi-task window
US20100017152A1 (en) * 2006-06-10 2010-01-21 Mark David George Potter Non-Contact Apparatus for Monitoring the Height of Contents of a Moving Container, a Monitoring Station Including the Apparatus and a Non-Contact Method of Monitoring the Height of Contents of a Container
US9731211B2 (en) 2014-07-16 2017-08-15 Traxxas, L.P. On-board audio system for a model vehicle
USD828461S1 (en) 2014-10-01 2018-09-11 Traxxas, LP Transducer mount

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH645227A5 (fr) * 1981-12-22 1984-09-14 Multiphonie Sa Transducteur electro-acoustique.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2252846A (en) * 1938-09-30 1941-08-19 Associated Electric Lab Inc Acoustic device
US2501032A (en) * 1945-11-30 1950-03-21 Rca Corp Permanent magnet assembly for electrodynamic loud-speakers
US2848561A (en) * 1953-06-02 1958-08-19 Akg Akustische Kino Geraete Dynamic microphone
US3329777A (en) * 1963-05-24 1967-07-04 Plastic Mold & Engineering Co Dynamic ear phone
US3567870A (en) * 1968-07-25 1971-03-02 Harold D Linden Wall surface transducer system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2252846A (en) * 1938-09-30 1941-08-19 Associated Electric Lab Inc Acoustic device
US2501032A (en) * 1945-11-30 1950-03-21 Rca Corp Permanent magnet assembly for electrodynamic loud-speakers
US2848561A (en) * 1953-06-02 1958-08-19 Akg Akustische Kino Geraete Dynamic microphone
US3329777A (en) * 1963-05-24 1967-07-04 Plastic Mold & Engineering Co Dynamic ear phone
US3567870A (en) * 1968-07-25 1971-03-02 Harold D Linden Wall surface transducer system

Cited By (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4013846A (en) * 1975-08-28 1977-03-22 Minnesota Mining And Manufacturing Company Piston loudspeaker
US4257325A (en) * 1978-04-05 1981-03-24 Bertagni Jose J Mouting of a substantially planar diaphragm defining a sound transducer
US4384174A (en) * 1979-10-02 1983-05-17 Victor Company Of Japan, Limited Moving voice coil loudspeaker, peripheral diaphragm support, diaphragm construction, bobbin to diaphragm reinforcement
EP0139302A2 (de) * 1983-10-19 1985-05-02 Sanden Corporation Elektromechanischer Vibrator im Audio-Frequenz-Bereich
EP0139302A3 (en) * 1983-10-19 1987-12-09 Sanden Corporation Audio-frequency electromechanical vibrator
US4928312A (en) * 1988-10-17 1990-05-22 Amel Hill Acoustic transducer
US4997058A (en) * 1989-10-02 1991-03-05 Bertagni Jose J Sound transducer
US5425107A (en) * 1992-04-09 1995-06-13 Bertagni Electronic Sound Transducers, International Corporation Planar-type loudspeaker with dual density diaphragm
US5539835A (en) * 1992-04-09 1996-07-23 Sound Advance Systems, Inc. Planar-type loudspeaker with dual density diaphragm
US5693917A (en) * 1993-11-18 1997-12-02 Sound Advance Systems, Inc. Planar diaphragm loudspeaker
US5991424A (en) * 1995-04-28 1999-11-23 Sound Advance Systems, Inc. Planar diaphragm speaker with heat dissipator
EA000836B1 (ru) * 1995-09-02 2000-04-24 Нью Трэнсдьюсерз Лимитед Инерционный вибрационный преобразователь
US6751333B1 (en) 1995-09-02 2004-06-15 New Transducers Limited Inertial vibration transducers
US20050147273A1 (en) * 1995-09-02 2005-07-07 New Transducers Limited Acoustic device
US6904154B2 (en) 1995-09-02 2005-06-07 New Transducers Limited Acoustic device
US20060159293A1 (en) * 1995-09-02 2006-07-20 New Transducers Limited Acoustic device
US7158647B2 (en) 1995-09-02 2007-01-02 New Transducers Limited Acoustic device
US7194098B2 (en) 1995-09-02 2007-03-20 New Transducers Limited Acoustic device
WO1997009859A1 (en) * 1995-09-02 1997-03-13 New Transducers Limited Inertial vibration transducers
US6618487B1 (en) 1996-09-03 2003-09-09 New Transducers Limited Electro-dynamic exciter
WO1998034320A2 (en) * 1997-01-31 1998-08-06 New Transducers Limited Electro-dynamic inertial vibration exciter
AU725230B2 (en) * 1997-01-31 2000-10-12 New Transducers Limited Electro-dynamic exciter
WO1998034320A3 (en) * 1997-01-31 1998-11-19 New Transducers Ltd Electro-dynamic inertial vibration exciter
US20020064294A1 (en) * 1997-03-25 2002-05-30 Pioneer Electronic Corporation Speaker apparatus and manufacturing method thereof
US6343136B2 (en) * 1997-03-25 2002-01-29 Pioneer Electronic Corporation Speaker apparatus and manufacturing method thereof
US6817084B2 (en) 1997-03-25 2004-11-16 Pioneer Electronic Corporation Method for manufacturing a speaker apparatus
US6519347B1 (en) * 1997-07-03 2003-02-11 New Transducers Limited Panel-form loudspeakers
WO1999002012A1 (en) * 1997-07-03 1999-01-14 New Transducers Limited Panel-form loudspeakers
US6347149B1 (en) 1998-05-15 2002-02-12 Harman Audio Electronic Systems Gmbh Driver for a flat acoustic panel
WO1999060820A1 (de) * 1998-05-15 1999-11-25 Harman Audio Electronic Systems Gmbh Treiber für flaches klangpaneel
US6574347B1 (en) * 2000-11-17 2003-06-03 Logitech Europe S.A. Flat-panel loudspeaker with compressed dampeners
US20040037446A1 (en) * 2001-07-19 2004-02-26 Akinori Hasegawa Speaker and method of manufacturing the speaker
US7024015B2 (en) * 2001-07-19 2006-04-04 Matsushita Electric Industrial Co., Ltd. Speaker and method of manufacturing the speaker
US20030031324A1 (en) * 2001-08-07 2003-02-13 Richard Lukacovic Solenoid for an electrolarynx
US7109959B2 (en) 2002-02-06 2006-09-19 Andersen Corporation Multi-task window
US7180489B2 (en) 2002-02-06 2007-02-20 Andersen Corporation Automated multi-task window assembly
US20040056829A1 (en) * 2002-02-06 2004-03-25 Libby James B. Automated multi-task window assembly
US6929091B2 (en) 2002-10-28 2005-08-16 Sound Advance Systems, Inc. Planar diaphragm loudspeaker and related methods
US20040129492A1 (en) * 2002-10-28 2004-07-08 Alejandro Bertagni Planar diaphragm loudspeaker and related methods
US20040211310A1 (en) * 2003-04-25 2004-10-28 Takashi Hagiwara Sound pickup device for percussion instrument
US7256342B2 (en) * 2003-04-25 2007-08-14 Yamaha Corporation Sound pickup device for percussion instrument
US20100017152A1 (en) * 2006-06-10 2010-01-21 Mark David George Potter Non-Contact Apparatus for Monitoring the Height of Contents of a Moving Container, a Monitoring Station Including the Apparatus and a Non-Contact Method of Monitoring the Height of Contents of a Container
US9731211B2 (en) 2014-07-16 2017-08-15 Traxxas, L.P. On-board audio system for a model vehicle
US9861905B2 (en) 2014-07-16 2018-01-09 Traxxas Lp On-board audio system for a model vehicle
USD828461S1 (en) 2014-10-01 2018-09-11 Traxxas, LP Transducer mount
USD834111S1 (en) 2014-10-01 2018-11-20 Traxxas Lp Transducer mount

Also Published As

Publication number Publication date
FR2141983A1 (de) 1973-01-26
NL7208047A (de) 1972-12-19
DE2229239A1 (de) 1972-12-21
DK137820C (de) 1978-10-09
JPS5514600B1 (de) 1980-04-17
FR2141983B3 (de) 1975-08-08
DK137820B (da) 1978-05-08

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