High Quality Content by WIKIPEDIA articles! The rotary dial is a device mounted on or in a telephone or switchboard that is designed to send electrical pulses, known as pulse dialing, corresponding to the number dialed. The early form of the rotary dial used lugs on a finger plate instead of holes. Almon Brown Strowger filed the first patent for a rotary dial, U.S. patent#486,909, on December 21, 1891 that was later issued to him on November 29, 1892.