1324058 Telephone sets INTERNATIONAL STANDARD ELECTRIC CORP 2 Dec 1971 [10 Dec 1970] 55958/71 Heading H4J A telephone headset/handset comprises two similar halves hinged together in the region of the microphone, spring biased towards each other and shaped for use as a handset when folded and a headset when opened out. Various embodiments for use in wall or desk substation sets are described. In one embodiment the dial mechanism and radio equipment of a mobile handset are carried in a pocket-size housing coupled to the handset by a cord which functions also as an antenna. The set may have provision for controlling the incoming sound level manually or automatically. As shown a handset is divided longitudinally into two halves 20 and 21 coupled by a hinge portion 11 containing the microphone. The two halves can be swung apart as shown against the action of a spring in the hinge portion 11 to allow plugs 18 associated with receivers, one in each half, to be engaged in the ears of a user. Recesses 17 and edges 19 further hold the set on the head of a user. In a modification only one receiver is provided and sound is also coupled to the other ear of the user via an acoustic tube through the two halves of the handset/headset.
