GB481740A - Improvements in or relating to telephone receivers - Google Patents
Improvements in or relating to telephone receiversInfo
- Publication number
- GB481740A GB481740A GB2521736A GB2521736A GB481740A GB 481740 A GB481740 A GB 481740A GB 2521736 A GB2521736 A GB 2521736A GB 2521736 A GB2521736 A GB 2521736A GB 481740 A GB481740 A GB 481740A
- Authority
- GB
- United Kingdom
- Prior art keywords
- diaphragm
- hole
- receiver
- ear
- space
- 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
Links
- 239000002775 capsule Substances 0.000 abstract 1
- 210000000845 cartilage Anatomy 0.000 abstract 1
- 239000004744 fabric Substances 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
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
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/225—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only for telephonic receivers
Landscapes
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
Abstract
481,740. Receivers. STANDARD TELEPHONES & CABLES, Ltd., POCOCK, L. C., and ROBERTON, J. S. P. Sept. 16, 1936, No. 25217. [Class 40 (iv)] In a telephone receiver the dimensions of the space above the diaphragm and of a hole or holes leading from this space to the outer air are chosen so that the receiver has an upper resonance at frequency below 3300 cycles per sec. and preferably approximately 2900 cycles per second when the receiver is closed on an ear having an average acoustic impedance characteristic-i.e. an ear which loads a receiver with an acoustic impedance approximately equal to the impedance of three cubic centimetres of air, when placed against a telephone receiver. In particular, the volume of the space-above the diaphragm is preferably between 0À35 and 2À30 cc. and the acoustic mass of the hole or holes leading from the space to the outer air is between - 003 and À023 grams /cm.<4>, the actual values being chosen in accordance with formulae set out in the Specification. The invention may be applied to a receiver having its diaphragm clamped to a casing an by ear cap, Fig. 3 (not shown) or to capsule type receivers, Figs. 4, 5 and 8. The space 8 above the diaphragm is shaped as described in Specification 266,395, [Class 40 (iv)], or may be approximately conical. In the receiver shown in Fig. 4 the diaphragm 4 is clamped to a casing 9 by a ring 10 which forms an abutment for the inner surface of the ear cap and in Fig. 5 the ring 10 is extended in the form of a cover 11 which constitutes. the upper wall of the chamber above the diaphragm and is provided with a hole 12 opposite the hole 6 in the ear cap 5. As shown in Fig. 7, the outer surface of the ear cap 5 is formed with recesses 13 in communication with the hole 6 to allow the passage of sound if the hole 6 is covered by the cartilage of the ear. In a further modification, Fig. 8, a chamber of depth 0À20 cm. is formed below the diaphragm 4 by a plate 15 having a hole 14 about 0À23 cm. in diameter at about 1À27 cm. from its centre and covered bv silk cloth 16 to provide acoustic resistance between the chamber underneath the diaphragm and the chamber below the plate 15.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2521736A GB481740A (en) | 1936-09-16 | 1936-09-16 | Improvements in or relating to telephone receivers |
| FR821588D FR821588A (en) | 1936-09-16 | 1937-05-04 | Telephone receivers or the like |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2521736A GB481740A (en) | 1936-09-16 | 1936-09-16 | Improvements in or relating to telephone receivers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB481740A true GB481740A (en) | 1938-03-16 |
Family
ID=10224101
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2521736A Expired GB481740A (en) | 1936-09-16 | 1936-09-16 | Improvements in or relating to telephone receivers |
Country Status (2)
| Country | Link |
|---|---|
| FR (1) | FR821588A (en) |
| GB (1) | GB481740A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE854670C (en) * | 1948-10-02 | 1952-11-06 | Electroacustic Ges M B H | Damping device for telephones and microphones |
-
1936
- 1936-09-16 GB GB2521736A patent/GB481740A/en not_active Expired
-
1937
- 1937-05-04 FR FR821588D patent/FR821588A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE854670C (en) * | 1948-10-02 | 1952-11-06 | Electroacustic Ges M B H | Damping device for telephones and microphones |
Also Published As
| Publication number | Publication date |
|---|---|
| FR821588A (en) | 1937-12-08 |
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