US2174128A - Loudspeaker - Google Patents

Loudspeaker Download PDF

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Publication number
US2174128A
US2174128A US185110A US18511038A US2174128A US 2174128 A US2174128 A US 2174128A US 185110 A US185110 A US 185110A US 18511038 A US18511038 A US 18511038A US 2174128 A US2174128 A US 2174128A
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US
United States
Prior art keywords
loud
platform
inclination
sound
speaker
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
US185110A
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English (en)
Inventor
Jyrch Herbert
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Individual
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Individual
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Filing date
Publication date
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Publication of US2174128A publication Critical patent/US2174128A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H04R1/345—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for loudspeakers

Definitions

  • This invention relates to a loud-speaker for loud-speaker installations on railway platforms etc. It has for its object to reduce as much as possible the transmission of sound to neighbour- 5 ing platforms, thus directing the sound towards the platform itself, and this is attained by the fitting of the loud-speaker to the back of a tubular member open towards the front, which is somewhat inclined to the horizontal so that the desired directive effect is attained. It is further improved by the provision of a broad slot in this tubular member on its underside. Preferably, downwardly bent guide surfaces are fitted, e. g. attached to the edges of the slots.
  • the low speech frequencies which are not capable of being confined, immediately balance themselves out downwards I through the slot provided and can, as in effect, be short-circuited.
  • a further advantage of this method is to be seen in the fact that there is also good clear distribution in the region of the platform directly under the loud-speaker. There is very little side sound spreading, because the slot directs the sound through the guide surfaces there provided.
  • the electro-mechanical part e. g. a cone reproducer, is arranged in the center of a tubular member, which preferably consists of two casing sections extending to opposite sides oflthe cone.
  • the rear part a different inclination, i. e., the rear part a steeper inclination than the front part, so that one section transmits about one-third and the other about, two-thirds of the entire length of the transmitting range.
  • the rear part of the casing having the steeper inclination is so .directed that the sound fades out at about one-third of the distance from the casingconstituting the front part of the next loud-speaker, whereas the said front part of the neighbouring loudspeaker covers two-thirds of this distance.
  • the loud-speaker is so constructed that it transmits the sounds to both ends.
  • Two tubular members, I and 2 having the flanges F and F support the flange 3 of the membrane or diaphragm of the loud speaker. That is to say, the flanges F and F clamp the membrane or a part thereof between the same and suitable bolts B may be used for connecting the flanges F and F in the conventional manner.
  • the said tubular members I and 2 are obliquely cut at I a and 2a and are provided in their lower part with a slot lb, 2b respectively. These slots are bounded laterally by a guide surface lo and 2c respectively.
  • the inclination of the tubular member 2 to the horizontal is greater than the inclination of the tubular member I.
  • This degree of inclination depends on the distance from each other of two loud-speakers.
  • the inclination is preferably so chosen that the part 2 has a range of one-third and the part I twothirds of the complete length of the transmitting range. Practical experiments with such meas;- urement have given extraordinarily good clarity and the smallest possible lateral transmission towards the neighbouring platform.
  • the present invention relates to a loud-speaker of the public address type, which has particular adaptability to use in connection with the loading platforms in railway stations.
  • a loud-speaker of the public address type which has particular adaptability to use in connection with the loading platforms in railway stations.
  • a sounddirecting construction for loudspeakers of the public "address type including in combination, an electro-mechanical sound reproducingunit, and a pair of oppositely extending downwardly inclined tubular casings, located one at each side of said imit, said casings being of substantially uniform diameter throughout and npen at their outer ends, the bottom portion of each casing being provided with a slot extending inwardly from its open end to permit 10w speech frequencies to escape downwardly before reaching the said open end.
  • one casing is of shorter length than the other, said casing of shorter length having a greater down ward inclination than said other sections thereby to provide a diiferential sound transmitting range between the casings.
  • a sound directing construction for loudspeakers of the public address type particularly adapted to be supported above a railway station platform including in combination, an electromechanical sound reproducing unit and tubular casing sections located one at each side of said unit, said sections being inclined downwardly from the unit toward the platform and each having a slot at its bottom side.

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  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)
US185110A 1936-11-25 1938-01-15 Loudspeaker Expired - Lifetime US2174128A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE487576X 1936-11-25

Publications (1)

Publication Number Publication Date
US2174128A true US2174128A (en) 1939-09-26

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ID=6543652

Family Applications (1)

Application Number Title Priority Date Filing Date
US185110A Expired - Lifetime US2174128A (en) 1936-11-25 1938-01-15 Loudspeaker

Country Status (4)

Country Link
US (1) US2174128A (en:Method)
BE (1) BE424804A (en:Method)
FR (1) FR829844A (en:Method)
GB (1) GB487576A (en:Method)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3268030A (en) * 1965-04-13 1966-08-23 Finn H Magnus Acoustic system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8351630B2 (en) * 2008-05-02 2013-01-08 Bose Corporation Passive directional acoustical radiating

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3268030A (en) * 1965-04-13 1966-08-23 Finn H Magnus Acoustic system

Also Published As

Publication number Publication date
GB487576A (en) 1938-06-22
BE424804A (en:Method)
FR829844A (fr) 1938-07-07

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