At&t Bell Laboratories

Bell Telephone Laboratories

Frederick A Rosebrock

John N McGarvey

Alvin R Tilley

Jeffrey Phillip McAteer

John C Baumhauer, Jr

Larry Allen Marcus

Richard M Sachs

Perry K White

Clinton D Gibler

Coupling apparatus for a telephone handset comprises a handset-coupling cradle having a dome at one end thereof for locating the earpiece (receiver) of the handset, and sound ports at the other end of the cradle in the region where the mouthpiece (microphone) of the handset resides. The handset-coupling cradle is shaped to accommodate a variety of different handset styles. An inductive sensor is mounted within the dome and it responds to electromagnetic fields generated by the handset receiver. Such a sensor eliminates the need to closely couple the receiver to the apparatus. A low acoustic impedance loudspeaker is mounted beneath the sound ports for acoustically coupling signals to the handset's microphone. Such a loudspeaker eliminates the need to closely couple the microphone to the apparatus.

Coupling apparatus for telephone handsets

A directional microphone assembly is constructed from a first-order-gradient microphone element enclosed within a housing, molded from an acoustically-opaque, resilient material such as Ethylene-Propylene-Diene-Monomer. The microphone element includes a diaphragm which moves under the influence of sound pressures applied on its opposite surfaces to generate an electrical signal which is proportional to the differential sound pressure. The housing includes a first acoustically-transparent channel for communicating sound pressure from a first opening in the housing to one surface of the diaphragm, and a second acoustically-transparent channel for communicating sound pressure from a second opening in the housing to the other surface of the diaphragm. The housing supports the microphone element and forms a continuous seal around its perimeter so that sound pressure in one channel does not leak into the other. The distance between the openings is relatively large in order to improve the sensitivity and directivity of the microphone. Moreover, the directional microphone assembly is configured to be embedded within, or behind, an exterior surface of sound-input equipment with the openings of the housing located along the exterior surface. The resilient housing structure forms a seal with the sound-input equipment surface.

Directional microphone assembly

Wall-mounted, coinless public telephone

The switch comprises a unitary dielectric support member including a base portion to which the fixed ends of a plurality of pairs of cantilever contact springs are secured. Guide portions of the support member define a channel, and a plurality of cam follower portions integrally hinged to the base portion respectively extend between the free ends of an associated contact spring of each pair and the channel. An actuator positioned within the channel includes cam portions for engaging the cam follower portions of the support member and deflecting them so as to displace the associated contact springs.

Cam actuated switch

Growing community of inventors

Greenfield, IN, United States of America

Frederick A Rosebrock