US2483231A - Loud-speaking telephone set with low acoustic coupling - Google Patents

Loud-speaking telephone set with low acoustic coupling Download PDF

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Publication number
US2483231A
US2483231A US691279A US69127946A US2483231A US 2483231 A US2483231 A US 2483231A US 691279 A US691279 A US 691279A US 69127946 A US69127946 A US 69127946A US 2483231 A US2483231 A US 2483231A
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US
United States
Prior art keywords
reflector
axis
loudspeaker
telephone set
plane
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
US691279A
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English (en)
Inventor
Edward S Peterson
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.)
Automatic Electric Laboratories Inc
Original Assignee
Automatic Electric Laboratories Inc
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 to BE474660D priority Critical patent/BE474660A/xx
Application filed by Automatic Electric Laboratories Inc filed Critical Automatic Electric Laboratories Inc
Priority to US691279A priority patent/US2483231A/en
Priority to FR949759D priority patent/FR949759A/fr
Application granted granted Critical
Publication of US2483231A publication Critical patent/US2483231A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets

Definitions

  • This invention relates to improvements in acoustic devices, and more specifically to certain relative arrangements of the loudspeaker means and transmitter means in a set for a two way telephone system.
  • a further feature of the invention is the positioning of thetransmitting means in a manner such that a minimum of sound waves reflected by the cylindrical parabolic reflector will reach the transmitting means.
  • Figure 1 is a diagrammatic view of a speaker equipped with a cylindrical parabolic reflector for the radiation of sound waves emitted by the speaker.
  • Figure 2 is a perspective view of a distant talkwaves of the reflector 2 ing telephone set comprising an illustrative embodiment of this invention.
  • a loudspeaker means 2 is positioned at the focal point of a cylindrical parabolic reflector l.
  • the reflector may be fashioned from a-rectangular sheet of metal or any other suitable reflector material so that it forms a refle-ctor shaped as a portion of a parabolic cylinder.
  • the loudspeaker means 2 is mounted with its approximate center located in a vertical line which passes through the foci of the cylindrical parabolic reflector and with its axis normal to the axis of the reflector. In this manner, an equal amount of waves are emitted on both sides of the plane passing through the foci and the vertex of the reflector.
  • the sound waves are reflected by the cylindrical parabolic reflector in a forward direction parallel to the axis as a beam of parallel rays. Since a greater efficiency of sound waves is experienced at the center of the loudspeaker means, viewing any horizontal plane, a concentration of waves will result at the outer edges of the reflector which become relatively weaker as the axis of the parabolic reflector is approached. This manner of wave reflection produces a beam of waves with a so-called dead spot along the axis of the reflector.
  • Figure 2 in perspective illustrates the transmitting means 3 mounted on cabinet 4 with its approximate center on a vertical line passing through the foci of the cylindrical parabolic reflector l and having its axis parallel to that of the reflector.
  • the loudspeaker means 2 is mounted on a baffle board it which is located along the axis of the reflector.
  • the cabinet 4 houses a conventional amplifier having a reflector I, an on-off switch 6, a volume control I, a dialing means 8 with connections to a telephone line, and a talk-answer, dial key 9.
  • the reflector is fashioned in the form of a cylindrical parabola from any suitable reflecting material.
  • the vertical edges of the reflector are attached to the vertical sides Of the cabinet and the horizontal edges are fashioned to effect a tight fit with the top and bottom inner surfaces of the cabinet on three sides by means of wood screws or the like, the fourth side being in contact with the reflector.
  • the working mechanism of key 9 is positioned in a small cutaway section of loaflie mounting board 10.
  • the on-oir switch 6 and volume control l have arm extension controls passing beyond the reflector to the amplifier.
  • the amplifier chassis is curved in conformance to the shape of the parabolic reflector.
  • the speaker means likewise may be of varied types.
  • a distant talking and listening telephone set comprising a focusing parabolic sound reflector, a telephone loudspeaker apparatus being positioned in said set within said reflector on avertical line which passes through the foci of said reflector and on a vertical plane coincident with the axis of said reflector so that a substantially equal volume of waves from said loudspeaker is transmitted on either side of the plane, said speaker having its axis normal to the axis of said reflector, and a transmitting means mounted on said set in such a position that its axis is coincident with said reflector axis and so that its approximate center lies on said vertical line, said set thereby eflective to operate with a minimum amount of feedback occurring in the transmit-.- ting means.
  • a parabolic reflector within the set shaped as a portion of a cylinder a loudspeaker mounted within said reflector at approximately the focus of the reflector and having its axis perpendicular to a plane passing through the focus and the vertex of the reflector, said speaker transmitting sound Waves approximately in equal volume on either side of said plane, and a microphone mounted above said speaker having its axis also falling within said plane and its central point lying approximately above said focus, whereby the minimum amount of feedback occurs in the microphone resulting from waves transmitted by said speaker.
  • a parabolic reflector therein, a loudspeaker mounted in said reflector so that its center is located approximately on a vertical line which passes through the foci of. said reflector and on a vertical plane coincident with the axis of said reflector so that a substantially equal volume of waves is transmitted on either side of the plane, said speaker having its axis normal to the axis of said reflector, and a transmitting means mounted in the device in such a position that its axis is coincident with said plane, said device thereby effective to operate with a minimum of acoustic coupling between said loudspeaker and said transmitting means,
  • a parabolic reflector therein in the form of a cylinder portion in the form of a cylinder portion, a loudspeaker positioned in said reflector on '4 a line passing through the foci of said reflector and having its axis normal to the axis of said reflector, said reflector thereby eflective to create a vertical plane of minimum sound waves, said vertical plane passing through the vertex and foci of said parabolic reflector, and a transmitting means whose axis is coincident with said dead plane, said set thereby operative to reduce acoustic coupling of said loudspeaker and said means.
  • a parabolic reflector a loudspeaker mounted within said reflector whose approximate center lies on a vertical line which passes through the foci of said reflector and being positioned on a vertical plane coincident with theaxis of said reflector, so that a substantially equal volume of waves are transmitted to either side of said plane, and a transmitting means whose approximate center lies on said vertical line.
  • a rectangular sheet of reflecting material fashioned the form of a parabolic reflector having a cylindrical shape, abaflie board mounted in a vertical plane coincident with the axis of said reflector, a speaker mounted on said battle board with its approx ⁇ ,
  • atransmitting means mounted with its approximate center located on said vertical line and in said dead plane, said set thereby effective to minimize acoustic coupling between said transmitting means and said speaker.
  • a cabinet a sheet of reflecting material fashioned in the form of a parabolic reflector, by having a shape similar to a parabolic cylinder portion, located in said cabinet and fastenedthereto at its outer edges, a bafiie board mounted in the cabinet along the axis of said reflector thereby dividing the enclosed re-.- flector area into two equal sections, a speaker mounted in the approximate center of the baffle board, said speaker having its approximate center on a'vertical line passing through the foci of said parabolic reflector and having its axis nor mal to the axis of said reflector, and transmit-v ting means mounted on said cabinet in a position such that a minimum amount of sound waves from said speaker .will reach said means.

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  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
US691279A 1946-08-17 1946-08-17 Loud-speaking telephone set with low acoustic coupling Expired - Lifetime US2483231A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE474660D BE474660A (enrdf_load_stackoverflow) 1946-08-17
US691279A US2483231A (en) 1946-08-17 1946-08-17 Loud-speaking telephone set with low acoustic coupling
FR949759D FR949759A (fr) 1946-08-17 1947-07-19 Poste téléphonique haut-parleur avec réflecteur parabolique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US691279A US2483231A (en) 1946-08-17 1946-08-17 Loud-speaking telephone set with low acoustic coupling

Publications (1)

Publication Number Publication Date
US2483231A true US2483231A (en) 1949-09-27

Family

ID=24775892

Family Applications (1)

Application Number Title Priority Date Filing Date
US691279A Expired - Lifetime US2483231A (en) 1946-08-17 1946-08-17 Loud-speaking telephone set with low acoustic coupling

Country Status (3)

Country Link
US (1) US2483231A (enrdf_load_stackoverflow)
BE (1) BE474660A (enrdf_load_stackoverflow)
FR (1) FR949759A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2580439A (en) * 1949-09-07 1952-01-01 Bell Telephone Labor Inc Directional acoustic system
DE1127406B (de) * 1958-05-02 1962-04-12 Ericsson Telefon Ab L M Fernsprechapparat, der als Lautfernsprecher arbeitet
WO2011042019A1 (en) * 2009-10-07 2011-04-14 Sl Audio A/S Dipole loudspeaker with diffuse rear radiation
TWI873460B (zh) * 2021-10-12 2025-02-21 日商住友重機械工業股份有限公司 回收方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2114680A (en) * 1934-12-24 1938-04-19 Rca Corp System for the reproduction of sound
US2177769A (en) * 1938-12-24 1939-10-31 Frank I Du Frane Company Inc Loud-speaking intercommunicating system
US2208160A (en) * 1939-10-19 1940-07-16 Harold J Mccreary Communication system
US2263233A (en) * 1938-06-24 1941-11-18 Telefunken Gmbh Acoustic apparatus
US2381174A (en) * 1942-11-16 1945-08-07 Brush Dev Co Communication system
US2385279A (en) * 1943-01-27 1945-09-18 Bell Telephone Labor Inc Distant talking loud-speaker telephone system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2114680A (en) * 1934-12-24 1938-04-19 Rca Corp System for the reproduction of sound
US2263233A (en) * 1938-06-24 1941-11-18 Telefunken Gmbh Acoustic apparatus
US2177769A (en) * 1938-12-24 1939-10-31 Frank I Du Frane Company Inc Loud-speaking intercommunicating system
US2208160A (en) * 1939-10-19 1940-07-16 Harold J Mccreary Communication system
US2381174A (en) * 1942-11-16 1945-08-07 Brush Dev Co Communication system
US2385279A (en) * 1943-01-27 1945-09-18 Bell Telephone Labor Inc Distant talking loud-speaker telephone system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2580439A (en) * 1949-09-07 1952-01-01 Bell Telephone Labor Inc Directional acoustic system
DE1127406B (de) * 1958-05-02 1962-04-12 Ericsson Telefon Ab L M Fernsprechapparat, der als Lautfernsprecher arbeitet
WO2011042019A1 (en) * 2009-10-07 2011-04-14 Sl Audio A/S Dipole loudspeaker with diffuse rear radiation
TWI873460B (zh) * 2021-10-12 2025-02-21 日商住友重機械工業股份有限公司 回收方法

Also Published As

Publication number Publication date
BE474660A (enrdf_load_stackoverflow)
FR949759A (fr) 1949-09-08

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