Who invented the looping line connected to touchtone phone set?
Answers: It's called a spring cord.
In 1938 retractile, spring, or spiral cords be introduced into the Bell System. A single cotton bundle containing the handset's four wires were fashioned into a spiral. This reduced the twisting and curling of conventional flat or braided cords. Spiral cords be popular immediately. AT&T's Events within Telecommunication History [ETH] reported that introduction began surrounded by April, with Western Electric providing 6,000 cords by November. Still, even near W.E. then producing 1,000 cords a week, the cords could not be kept surrounded by stock.
And for the record, I invented the Cordless phone cord.