GB592377A - Improvements in or relating to telephone handsets - Google Patents

Abstract

592,377. Telephone instruments and sets. TELEFONAKTIEBOLAGET L. M. ERICSSON. May 14, 1945, No. 12100. Convention date, April 6, 1944. [Class 40 (iv)] A telephone handset of the type comprising a contact spring set for switching the instrument either to the speaking position or to the position for receiving a calling signal is provided with a movably mounted cover-plate 5, located in front of the microphone 2, which moves within the microphone casing when the handset, with the receiver and microphone facing the support, is placed in its position of rest, the edge 13 of the plate engaging an arm 14 to operate the spring set 4 and switch the set to the position for receiving a calling signal. When the set is removed from its support the plate moves out from the casing and the set is switched to the speaking condition. The cover plate 5 has secured to one of its edges a spindle, seating in a socket 7 formed integrally with one half 1 of the handset casing and slotted to allow limited angular movement of the plate. Each squared end 9 of the spindle is mounted in one end of a spiral spring 11, the other end 12 of which bears against one edge of the socket 7, to urge the plate to the open position corresponding to the speaking position. The arched design of the cover plate ensures its closing under pressure from any direction. The socket 7 may alternatively be an individual part, or the microphone may be fixed within the cover-plate and move with it. A gravitationally operated locking device may be provided to prevent unintentional closing of the cover plate when the handset is held in the speaking position,