GB549643A - Improvements in or relating to telephone transmitters and receivers - Google Patents

Improvements in or relating to telephone transmitters and receivers

Info

Publication number
GB549643A
GB549643A GB6780/41A GB678041A GB549643A GB 549643 A GB549643 A GB 549643A GB 6780/41 A GB6780/41 A GB 6780/41A GB 678041 A GB678041 A GB 678041A GB 549643 A GB549643 A GB 549643A
Authority
GB
United Kingdom
Prior art keywords
pot
coil
permanent magnet
pole
moulding
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
Application number
GB6780/41A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB6780/41A priority Critical patent/GB549643A/en
Priority to US443424A priority patent/US2400662A/en
Publication of GB549643A publication Critical patent/GB549643A/en
Expired legal-status Critical Current

Links

Classifications

    • 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

Abstract

549,643. Magnets. STANDARD TELEPHONES & CABLES, Ltd., ROBERTON, J. S. P., and GAYFORD, M. L. May 27, 1941, No. 6780. [Class 35] [Also in Group XXXIX] In a moving-coil telephone instrument of the type having a short cylindrical permanent magnet 11, a pot 12, and an inner pole-piece 13, the pole-pieces and permanent magnet are fixed relatively to one another by a setting material, such as a synthetic resin. In the transmitter shown in Fig. 1, the permanent magnet 11, the pot 12, and pole-piece 13 are assembled loosely, the polepiece is positioned accurately by a temporary insert in the air-gap, and the pot is filled, through an aperture in the pot, with a setting material 19 which also forms an insulating casing. The moulding material is allowed to flow into the pot up to a predetermined level to secure the proper air-space behind the coil; the holes in the pot through which the moulding material flows are afterwards drilled out and covered with silk to provide acoustic damping. The inner polepiece 13 is flanged downwardly as shown, and supports a moulded member 17 having recesses 18, behind the domed diaphragm 16. A magnetic screen 22 and casing 23 reduce the external field to a minimum. The coil 15 of aluminium tape is connected to the tips of terminal screws 25 moulded in the frame. Fig. 3 shows a capsuletype microphone, with one terminal of the coil connected to the back screen 23 and the other to an insulated central contact 26. A disc 27 of high permeability in the bottom of the pot 12 reduces the flux leakage from the base of the pot. An acoustic resistance is provided by lambswool filling slots in the moulding 29 secured to the pressed cup 12. Specifications 351,560 and 377,461 are referred to.
GB6780/41A 1941-05-27 1941-05-27 Improvements in or relating to telephone transmitters and receivers Expired GB549643A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB6780/41A GB549643A (en) 1941-05-27 1941-05-27 Improvements in or relating to telephone transmitters and receivers
US443424A US2400662A (en) 1941-05-27 1942-05-18 Telephone transmitter and receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6780/41A GB549643A (en) 1941-05-27 1941-05-27 Improvements in or relating to telephone transmitters and receivers

Publications (1)

Publication Number Publication Date
GB549643A true GB549643A (en) 1942-12-01

Family

ID=9820601

Family Applications (1)

Application Number Title Priority Date Filing Date
GB6780/41A Expired GB549643A (en) 1941-05-27 1941-05-27 Improvements in or relating to telephone transmitters and receivers

Country Status (2)

Country Link
US (1) US2400662A (en)
GB (1) GB549643A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2359213A (en) * 1999-10-29 2001-08-15 Kef Audio Elliptical dome loudspeaker

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566604A (en) * 1948-03-16 1951-09-04 William C Eaves Electrodynamic loud-speaker assembly
US2551447A (en) * 1948-05-20 1951-05-01 Operadio Mfg Co Electrodynamic speaker
US2567365A (en) * 1948-08-04 1951-09-11 Bell Telephone Labor Inc Polarized operator for telephone receivers
GB687363A (en) * 1949-05-04 1953-02-11 Hans Christian Hansen Improvements in electrodynamic pick-up's
BE496097A (en) * 1949-06-04
US2801294A (en) * 1950-11-24 1957-07-30 Holmberg & Co Kommanditgesells Electrodynamic receiving apparatus
BE505468A (en) * 1951-04-23
US2749393A (en) * 1951-05-01 1956-06-05 Pickering Associates Inc Molded sound reproducer and method of making the same
US3014099A (en) * 1955-01-10 1961-12-19 Fiala Walter Electroacoustic transducer
NL301514A (en) * 1962-12-13
US4720866A (en) * 1985-09-20 1988-01-19 Seaboard Digital Systems, Inc. Computerized stethoscopic analysis system and method
US7480209B2 (en) * 2007-05-29 2009-01-20 Harris Corporation Submersible loudspeaker assembly
US20100054520A1 (en) * 2008-08-28 2010-03-04 Jason Myles Cobb Loudspeaker

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2359213A (en) * 1999-10-29 2001-08-15 Kef Audio Elliptical dome loudspeaker
GB2359213B (en) * 1999-10-29 2004-05-19 Kef Audio High frequency transducer
US6792127B1 (en) 1999-10-29 2004-09-14 Kef Audio (Uk) Limited Elliptical dome for high frequency transducer

Also Published As

Publication number Publication date
US2400662A (en) 1946-05-21

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