US3222463A - Sound transducer for dictating equipment - Google Patents

Sound transducer for dictating equipment Download PDF

Info

Publication number
US3222463A
US3222463A US218240A US21824062A US3222463A US 3222463 A US3222463 A US 3222463A US 218240 A US218240 A US 218240A US 21824062 A US21824062 A US 21824062A US 3222463 A US3222463 A US 3222463A
Authority
US
United States
Prior art keywords
diaphragm
opening
front wall
flat
shallow
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
US218240A
Inventor
Gorike Rudolf
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.)
AKG Acoustics GmbH
Original Assignee
AKG Akustische und Kino Geraete GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from AT746461A external-priority patent/AT228860B/en
Priority claimed from AT749561A external-priority patent/AT227807B/en
Application filed by AKG Akustische und Kino Geraete GmbH filed Critical AKG Akustische und Kino Geraete GmbH
Application granted granted Critical
Publication of US3222463A publication Critical patent/US3222463A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
    • B29C44/10—Applying counter-pressure during expanding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/755—Membranes, diaphragms

Definitions

  • the electro-acoustic transducers used with dictating equipment are preferably adapted to take the dictation as well as to reproduce the same.
  • This practice is suitable because it results in a reduced space requirement and in reduced costs. From the acoustic aspect, however, special measures must be adapted to ensure a satisfactory reproduction.
  • the dual-function transducers have been successful and it is now desired to improve the reproducing properties of such a transducer. This endeavour encounters difficulties because the space available in a handy, handle-shaped housing is relatively small, so that only transducers having the dimensions of usual microphones can be incorporated. Owing to their small size, these transducers must be overmodulated to obtain a sufficient volume of sound, and then give a distorted reproduction. For this reason it has been attempted initially to replace the small circular diaphragm by oval diaphragms of plastic sheeting or paper. The results, however, are not satisfactory because such diaphragms lack the stiffness required.
  • the invention proposes to use with dictating equipment a sound transducer which is characterized in that it is provided with a substantially flat diaghragm of foamed plastic, the rim of which diaphragm is suitably moulded to small thickness and is preferably molded with corrugations for increased resiliency, the diaphragm extending as far as to the rims of the housing part disposed above the change-over means.
  • the diaphragm adjoins this housing part at the contour line thereof so that the space available can be utilized as fully as possible.
  • the moving coil is suitably centrically or eccentrically secured to the diaphragm so that an improved adaption to the space conditions is enabled.
  • the diaphragm may also be suitable to give the diaphragm a slightly conical shape on the side facing the actuating system and a planar shape on the emitting side.
  • the diaphragm may also consist of a shaped body having stiffening ribs.
  • the advantages resulting from the use of a diaphragm of foamed plastic are truly surprising.
  • the diaphragm of foamed plastic fully utilizes the space or area available for emitting sound. Where as it is still-er than concial diaphragrns of paper or plastic, it does not require a greater depth for installation.
  • the diaphragm can be made at very low cost and when consisting of foamed plastic having a closed surface is absolutely insensitive to moisture.
  • FIG. 1a is a perspective View showing the foamed plastic diaphragm
  • FIGS. 1b, 1c, 1d are sectional views taken on line ab of FIG. 1 and showing transverse sectional forms of the diaphragm
  • FIG. 2a is a transverse sectional view showing a transducer according to the invention
  • FIG. 2b is a front elevation thereof.
  • the diaphragm of foamed plastic has a shape which is adapted to the largest possible opening in the handle-shaped housing.
  • the transverse sectional view of the diaphragm shown in FIG. 1b, taken on line ab of FIG. 1a, indicates that the main body of diaphragm has a relatively large thickness compared to the rim zone.
  • the thickness ratio may be, e.g., 30:1 so that a diaphragm having a thickness of 3 mm. has a rim 0.1 mm. thick. This enables the provision of a very narrow rim zone so that the diaphragm itself has the largest possible area.
  • the rim zone may be moulded to have beads or corrugations although this is not essential.
  • FIGS. 2a and 2b show an illustrative embodiment of a handle microphone provided with the transducer according to the invention.
  • the diaphragm 1 having a conical body, as shown in FIG. 1c, is adhered to the dome-shaped portion 2 of a small diaphragm provided with a moving coil
  • the magnet systems and the switch gear or control means 4 consisting of push but tons 5 and slides 6 are known means for controlling the function of dictating equipment.
  • a visual signal 7 serves for supervising the functions.
  • the moving coil may be directly secured to the diaphragm of foamed plastic.
  • the sound transducer may be coupled to acoustic elements known per se to provide various directional patterns.
  • the rear side of the diaphragm may communicate through connecting ducts with the openings at the rear side of the handle, or with the interior space of the housing.
  • the first arrangement will result in a unidirectional pattern, the second in an omnidirectional one.
  • a shutter which may be connected to the slide 6, for instance, may serve for effecting an acoustic changeover so that a directional microphone is available for recording and a receiver having an omnidirectional pattern for the reproduction.
  • the transducer may be surrounded by a housing (indicated by dash lines in FIG. 2a and provided with the reference numeral 8).
  • the slide 6 may be used to open and close openings in the shell member 8 and 9 and these openings may be provided with acoustic frictional resistances.
  • the transducer may be friction-controlled for recording and mass-controlled for reproducing sound.
  • a sound transducer for dictating equipment comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an elongated opening in the upper portion of its front wall formed with a peripheral seat, the opening extending more than half the length of the front wall; control means mounted on said front wall on the lower portion thereof; a substantially flat molded diaphragm of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a fiat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm.
  • a sound transducer for dictating equipment comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; a substantially fiat molded diaphragm of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system Within the upper portion of said housing including a movable drive element in cont-act with a small area of the inner surface of the body portion of said diaphragm; said rim portion being formed with corrugations for increased resiliency.
  • a sound transducer for dictating equipment comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; substantially flat diaphragm molded of foamed plastic closing said opening, said diaphragmhaving a relatively thick main body portion within said openingand bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm; said diaphragm being planar on one side and having a shallow trapez'oid transverse section.
  • a sound transducer for dictating equipment comprising, in combination, a hollow flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; a substantially flat diaphragm molded of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm, said diaphragm consisting of a shaped body formed with stiffening ribs.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Description

Dec. 7, 1965 R. GORIKE SOUND TRANSDUCER FOR DICTA'IING EQUIPMENT Filed Aug. 21, 1962 F/G2a F/G. 2b
F/G. la
United States Patent firm Filed Aug. 21, 1962, Ser. No. 218,240 Claims priority, application Austria, Oct. 5, 1961,
A 7,495/61 5 Claims. (Cl. 179--115.5)
The electro-acoustic transducers used with dictating equipment are preferably adapted to take the dictation as well as to reproduce the same. This practice is suitable because it results in a reduced space requirement and in reduced costs. From the acoustic aspect, however, special measures must be adapted to ensure a satisfactory reproduction. Nevertheless, the dual-function transducers have been successful and it is now desired to improve the reproducing properties of such a transducer. This endeavour encounters difficulties because the space available in a handy, handle-shaped housing is relatively small, so that only transducers having the dimensions of usual microphones can be incorporated. Owing to their small size, these transducers must be overmodulated to obtain a sufficient volume of sound, and then give a distorted reproduction. For this reason it has been attempted initially to replace the small circular diaphragm by oval diaphragms of plastic sheeting or paper. The results, however, are not satisfactory because such diaphragms lack the stiffness required.
For this reason the invention proposes to use with dictating equipment a sound transducer which is characterized in that it is provided with a substantially flat diaghragm of foamed plastic, the rim of which diaphragm is suitably moulded to small thickness and is preferably molded with corrugations for increased resiliency, the diaphragm extending as far as to the rims of the housing part disposed above the change-over means. As a result, the diaphragm adjoins this housing part at the contour line thereof so that the space available can be utilized as fully as possible.
The moving coil is suitably centrically or eccentrically secured to the diaphragm so that an improved adaption to the space conditions is enabled.
It may also be suitable to give the diaphragm a slightly conical shape on the side facing the actuating system and a planar shape on the emitting side.
The diaphragm may also consist of a shaped body having stiffening ribs.
The advantages resulting from the use of a diaphragm of foamed plastic are truly surprising. The diaphragm of foamed plastic fully utilizes the space or area available for emitting sound. Where as it is still-er than concial diaphragrns of paper or plastic, it does not require a greater depth for installation. Besides, the diaphragm can be made at very low cost and when consisting of foamed plastic having a closed surface is absolutely insensitive to moisture.
An illustrative embodiment is shown in the figures of the accompanying drawing, in which FIG. 1a is a perspective View showing the foamed plastic diaphragm, FIGS. 1b, 1c, 1d are sectional views taken on line ab of FIG. 1 and showing transverse sectional forms of the diaphragm, FIG. 2a is a transverse sectional view showing a transducer according to the invention and FIG. 2b is a front elevation thereof.
As is shown in FIG. la, the diaphragm of foamed plastic has a shape which is adapted to the largest possible opening in the handle-shaped housing. The transverse sectional view of the diaphragm shown in FIG. 1b, taken on line ab of FIG. 1a, indicates that the main body of diaphragm has a relatively large thickness compared to the rim zone. The thickness ratio may be, e.g., 30:1 so that a diaphragm having a thickness of 3 mm. has a rim 0.1 mm. thick. This enables the provision of a very narrow rim zone so that the diaphragm itself has the largest possible area. To increase the elasticity, the rim zone may be moulded to have beads or corrugations although this is not essential.
FIGS. 2a and 2b show an illustrative embodiment of a handle microphone provided with the transducer according to the invention. The diaphragm 1 having a conical body, as shown in FIG. 1c, is adhered to the dome-shaped portion 2 of a small diaphragm provided with a moving coil The magnet systems and the switch gear or control means 4 consisting of push but tons 5 and slides 6 are known means for controlling the function of dictating equipment. A visual signal 7 serves for supervising the functions. Alternatively, the moving coil may be directly secured to the diaphragm of foamed plastic.
The sound transducer may be coupled to acoustic elements known per se to provide various directional patterns. For instance, the rear side of the diaphragm may communicate through connecting ducts with the openings at the rear side of the handle, or with the interior space of the housing. The first arrangement will result in a unidirectional pattern, the second in an omnidirectional one. A shutter, which may be connected to the slide 6, for instance, may serve for effecting an acoustic changeover so that a directional microphone is available for recording and a receiver having an omnidirectional pattern for the reproduction. The transducer may be surrounded by a housing (indicated by dash lines in FIG. 2a and provided with the reference numeral 8). To improve the frequency characteristic it is suitable to provide behind the diaphragm a low-volume air chamber, which is defined by a shell member 9 indicated in dotted lines. In addition to performing an electric switching operation, the slide 6 may be used to open and close openings in the shell member 8 and 9 and these openings may be provided with acoustic frictional resistances. In this case the transducer may be friction-controlled for recording and mass-controlled for reproducing sound.
I claim:
1. A sound transducer for dictating equipment comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an elongated opening in the upper portion of its front wall formed with a peripheral seat, the opening extending more than half the length of the front wall; control means mounted on said front wall on the lower portion thereof; a substantially flat molded diaphragm of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a fiat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm.
2. A sound transducer for dictating equipment comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; a substantially fiat molded diaphragm of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system Within the upper portion of said housing including a movable drive element in cont-act with a small area of the inner surface of the body portion of said diaphragm; said rim portion being formed with corrugations for increased resiliency.
3. A sound transducer for dictating equipment, comprising, in combination, a hollow, flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; substantially flat diaphragm molded of foamed plastic closing said opening, said diaphragmhaving a relatively thick main body portion within said openingand bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm; said diaphragm being planar on one side and having a shallow trapez'oid transverse section.
4. A sound transducer for dictating equipment comprising, in combination, a hollow flat and shallow, and elongated handle shape microphone housing having an opening in the upper portion of its front wall formed with a peripheral seat; control means mounted on said front wall on the lower portion thereof; a substantially flat diaphragm molded of foamed plastic closing said opening, said diaphragm having a relatively thick main body portion within said opening and bounded by a thin peripheral rim portion superposed on said peripheral seat; and a flat and shallow drive system within the upper portion of said housing including a movable drive element in contact with a small area of the inner surface of the body portion of said diaphragm, said diaphragm consisting of a shaped body formed with stiffening ribs.
5. A sound transducer as set forth in claim 1, in which said drive system is of electrodynamic type.
References Cited by the Examiner UNITED STATES PATENTS 1,918,422 7/1933 Nystrom 181-32 2,297,218 9/ 1942 Henrich et al. '18132 2,905,260 9/1959 Williams 181-32 2,926,741 3/1960 Rohn et al. 181-32 3,035,132 5/1962 Gorik-e et al. 179--167 3,052,785 9/1962 Herrmann et'al. 179-167 FOREIGN PATENTS 513,289 10/1939 Great Britain.
ROBERT H. ROSE, Primary Examiner.

Claims (1)

1. A SOUND TRANSDUCER FOR DICTATING EQUIPMENT COMPRISING, IN COMBINATION, A HOLLOW, FLAT AND SHALLOW, AND ELONGATED HANDLE SHAPE MICROPHONE HOUSING HAVING AN ELONGATED OPENING IN THE UPPER PORTION OF ITS FRONT WALL FORMED WITH A PERIPHERAL SEAT, THE OPENING EXTENDING MORE THAN HALF THE LENGTH OF THE FRONT WALL: CONTROL MEANS MOUNTED ON SAID FRONT WALL ON THE LOWER PORTION THEREOF; A SUBSTANTIALLY FLAT MOLDED DIAPHRAGM OF FOAMED PLASTIC CLOSING SAID OPENING, SAID DIAPHRAGM HAVING A RELATIVELY THICK MAIN BODY PORTION WITHIN SAID OPENING AND BOUNDED BY A THIN PERIPHERAL RIM PORTION SUPERPOSED ON SAID PERIPHERAL SEAT; AND A FLAT AND SHALLOW DRIVE SYSTEM WITHIN THE UPPER PORTION OF SAID HOUSING INCLUDING A MOVABLE DRIVE ELEMENT IN CONTACT WITH A SMALL AREA OF THE INNER SURFACE OF THE BODY PORTION OF SAID DIAPHRAGM.
US218240A 1961-10-04 1962-08-21 Sound transducer for dictating equipment Expired - Lifetime US3222463A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT746461A AT228860B (en) 1961-10-04 1961-10-04 Foam membrane for sound transducers
AT749561A AT227807B (en) 1961-10-05 1961-10-05 Sound transducers for dictation machines

Publications (1)

Publication Number Publication Date
US3222463A true US3222463A (en) 1965-12-07

Family

ID=25603855

Family Applications (2)

Application Number Title Priority Date Filing Date
US218240A Expired - Lifetime US3222463A (en) 1961-10-04 1962-08-21 Sound transducer for dictating equipment
US228335A Expired - Lifetime US3172498A (en) 1961-10-04 1962-10-04 Foamed plastic diaphragm for sound transducers

Family Applications After (1)

Application Number Title Priority Date Filing Date
US228335A Expired - Lifetime US3172498A (en) 1961-10-04 1962-10-04 Foamed plastic diaphragm for sound transducers

Country Status (6)

Country Link
US (2) US3222463A (en)
BE (1) BE623239A (en)
CH (1) CH412013A (en)
DE (2) DE1172730B (en)
GB (2) GB1017080A (en)
NL (1) NL283889A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3686446A (en) * 1968-12-19 1972-08-22 Manger J W Push-pull moving coil loudspeaker having electromagnetic centering means
US3740496A (en) * 1971-11-08 1973-06-19 Industrial Research Prod Inc Diaphragm assembly for electret transducer
USD244700S (en) * 1976-06-28 1977-06-14 Dictaphone Corporation Remote control microphone or similar article
USD244779S (en) * 1975-02-20 1977-06-21 Nihon Atsudenki Kabushiki Kaisha Microphone
USD244780S (en) * 1975-02-25 1977-06-21 Nihon Atsudenki Kabushiki Kaisha Microphone
CN101112118B (en) * 2004-12-20 2012-12-05 弗劳恩霍夫应用研究促进协会 Loudspeaker diaphragm and method for producing a loudspeaker diaphragm
USD830346S1 (en) * 2017-05-15 2018-10-09 Ching-Wen Chen Telephone type computer microphone
USD994647S1 (en) * 2021-08-31 2023-08-08 Ohma World 2 Inc. Microphone

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351719A (en) * 1964-02-05 1967-11-07 Electronic Res Associates Inc Loudspeaker assembly
DE1299041B (en) * 1966-04-06 1969-07-10 Nippon Gakki Co Ltd Seizo Kabu Membrane for flat speaker
AT274080B (en) * 1967-07-05 1969-09-10 Philips Nv Sound transducer with a foam membrane
US3708035A (en) * 1967-11-30 1973-01-02 Nippon Musical Instruments Mfg Diaphragm for loudspeakers
US3483946A (en) * 1967-12-30 1969-12-16 Nippon Musical Instruments Mfg Loudspeaker
US3767004A (en) * 1971-03-19 1973-10-23 A Liebscher Loudspeakers
NL8200690A (en) * 1982-02-22 1983-09-16 Philips Nv SPEAKER MEMBRANE CONTAINING A LAYER OF POLYMETHACRYLIMIDE FOAM.
US4635750A (en) * 1985-06-03 1987-01-13 Sharp Kabushiki Kaisha Loudspeaker diaphragm
DE3831706A1 (en) * 1988-09-17 1990-03-22 Bayer Ag MEMBRANE FOR SPEAKERS
AT405997B (en) * 1997-04-30 2000-01-25 Akg Acoustics Gmbh ELECTROACOUSTIC CONVERTER
GB2403091B (en) * 2003-06-18 2006-08-09 B & W Loudspeakers Diaphragms for loudspeaker drive units
JP6931613B2 (en) * 2015-02-05 2021-09-08 イーグル アコースティックス マニュファクチュアリング，エルエルシー Integrated voice coil and cone assembly and its manufacturing method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1918422A (en) * 1926-06-22 1933-07-18 United Res Corp Sound-reproducing device
GB513289A (en) * 1937-12-18 1939-10-09 Helmut Sell Diaphragm for receiving or reproducing sound vibrations and method for its manufacture
US2297218A (en) * 1937-04-24 1942-09-29 Hans E Henrich Loud-speaker
US2905260A (en) * 1955-02-24 1959-09-22 Muter Company Loud speaker diaphragm
US2926741A (en) * 1958-04-28 1960-03-01 Lab Equipment Corp Speaker
US3035132A (en) * 1958-07-25 1962-05-15 Akustische Und Kino Gerate Ges Switching device combined with sound transducer
US3052785A (en) * 1958-08-16 1962-09-04 Herrmann Gunter Sound recording machines

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE886758C (en) * 1953-07-02 Emil Dr Podszus Membrane for loudspeaker with cavity structure
GB596893A (en) * 1945-08-03 1948-01-13 Cossor Ltd A C Improvements relating to acoustic reproducers
DE900228C (en) * 1937-01-20 1953-12-21 Dr Emil Podszus Membrane of great rigidity for sound reproduction
DE974931C (en) * 1950-06-08 1961-06-08 Emil Dr Podszus Loudspeaker membrane made of frozen foam
DE972185C (en) * 1950-10-18 1959-06-04 Emil Dr Podszus Membrane with foam structure for loudspeakers

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1918422A (en) * 1926-06-22 1933-07-18 United Res Corp Sound-reproducing device
US2297218A (en) * 1937-04-24 1942-09-29 Hans E Henrich Loud-speaker
GB513289A (en) * 1937-12-18 1939-10-09 Helmut Sell Diaphragm for receiving or reproducing sound vibrations and method for its manufacture
US2905260A (en) * 1955-02-24 1959-09-22 Muter Company Loud speaker diaphragm
US2926741A (en) * 1958-04-28 1960-03-01 Lab Equipment Corp Speaker
US3035132A (en) * 1958-07-25 1962-05-15 Akustische Und Kino Gerate Ges Switching device combined with sound transducer
US3052785A (en) * 1958-08-16 1962-09-04 Herrmann Gunter Sound recording machines

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3686446A (en) * 1968-12-19 1972-08-22 Manger J W Push-pull moving coil loudspeaker having electromagnetic centering means
US3740496A (en) * 1971-11-08 1973-06-19 Industrial Research Prod Inc Diaphragm assembly for electret transducer
USD244779S (en) * 1975-02-20 1977-06-21 Nihon Atsudenki Kabushiki Kaisha Microphone
USD244780S (en) * 1975-02-25 1977-06-21 Nihon Atsudenki Kabushiki Kaisha Microphone
USD244700S (en) * 1976-06-28 1977-06-14 Dictaphone Corporation Remote control microphone or similar article
CN101112118B (en) * 2004-12-20 2012-12-05 弗劳恩霍夫应用研究促进协会 Loudspeaker diaphragm and method for producing a loudspeaker diaphragm
USD830346S1 (en) * 2017-05-15 2018-10-09 Ching-Wen Chen Telephone type computer microphone
USD994647S1 (en) * 2021-08-31 2023-08-08 Ohma World 2 Inc. Microphone

Also Published As

Publication number Publication date
NL283889A (en)
US3172498A (en) 1965-03-09
GB968951A (en) 1964-09-09
DE1172730B (en) 1964-06-25
CH412013A (en) 1966-04-30
BE623239A (en)
GB1017080A (en) 1966-01-12
DE1172731B (en) 1964-06-25

Similar Documents

Publication Publication Date Title
US3222463A (en) Sound transducer for dictating equipment
US4850016A (en) Microphone
US20170251292A1 (en) Audio Device With Acoustic Valve
US5555554A (en) Vented headset speaker
US3249873A (en) Miniaturized helmet exponential horn speaker for a portable radio receiver
US4027117A (en) Headphone
KR860001868Y1 (en) A speaker unit
FR2503516B1 (en) OMNIDIRECTIONAL ELECTRODYNAMIC SPEAKER FOR LOW AND MEDIUM SOUND SPECTRUM FREQUENCIES
US4313040A (en) Electro-acoustic transducer with free edge diaphragm
US3059720A (en) High frequency loudspeakers
CA2084787A1 (en) Loudspeakers
US5673330A (en) Microphone transducer with noise reducing member
JPS5660191A (en) Acoustic device for car
US3952834A (en) Embedded type speaker with over lying grill
US10820073B2 (en) Speaker box
US4010821A (en) Omnidirectional sympathetically driven sound reproduction device
US3293379A (en) Earphone
US3329777A (en) Dynamic ear phone
CN111970611B (en) Headset earphone
US3547221A (en) Acoustical apparatus
US2386996A (en) Sound translating apparatus
JP2000050386A (en) Condenser microphone with narrow directivity
US20210235182A1 (en) Electroacoustic earcups for open-back headphones
KR950008183Y1 (en) Speake
CN219269065U (en) Breathable loudspeaker dust cover