When did RCA get into phones?

[Bill Cahill]

While sifting through a box of new old stock RCA parts last night I discoverered a really strange one.
It' a 60's RCA that says "Telephone Jack".
Open the boox, and, it's a small plastic jack. There is a quarter inch round hole in the front.On the back there are 3 verytiny spring connectors very close to each other. This isn't your standard quarter inch phone jack, , and there are no shorting switches.
Just 3 tiny little contact connectors.
What type of phone would have used this jack?
When did RCA get into phones?
If you want a picture, I'll take one.
It's the strangest thing I've ever seen, and, by RCA, no less.....
Bill Cahill

[Dan/Panther]

Bill;
Post a photo, it sounds like a switchboard jack.
D/P