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
GB2828345A
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Individual
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Individual
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Priority to GB2828345ApriorityCriticalpatent/GB603649A/en
Publication of GB603649ApublicationCriticalpatent/GB603649A/en
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
Abstract
603,649. Sound reproducing instruments. JOHNSON, A. H. Oct. 26, 1945, No. 28283. [Class 40 (iv)] A sound reproducing device includes a field magnet having a centre pole 10 and an outer pole 8 separated by an air gap into which projects a coil connected to a diaphragm supported by a chassis 6 which is made of magnetic material and is secured to the magnet as shown so that it defines part of the outer surface of the air gap. The chassis may be made of mild steel, the body 12 of the magnet of magnetic alloy and the polepiece 8 and back plate 11 of soft iron.
GB2828345A1945-10-261945-10-26Improvements in sound-reproducing devices
ExpiredGB603649A
(en)