Automatic restoral mechanism for a pushbutton key telephone instrument

摘要

A mechanism for automatically restoring an operated and depressed pushbutton line key in a multi-line key telephone instrument. When the telephone instruments handset is returned to the instruments cradle, the cradle rotates a cradle shaft which in turn rotates a hookswitch and a restoral actuator mounted to the shaft. The hookswitch actuator operates hookswitch contact springs placing the instrument in the "on-hook" condition and simultaneously the restoral actuator moves a button restoral arm which swings horizontally about a pivot. Restoral linkage mounted to the restoral arm transfers the arms' motion to an interlock lever which also pivots applying a mechanical force on the line key latch bar, unlatching the depressed pushbutton and restoring it to its original or non-operated position.