LORIMER SYSTEM
TELEPHONES

The telephones used a "Signal Generator" to transmit the digits required to the Exchange. On the front of the telephone were four levers and a window associated with each lever would show the number required. The user would select the number required (0 to 9999) using the levers and then turn the crank on the side of the phone one revolution. The crank tensioned a spring which operated the "Signal Generator" and signalled to the exchange that the user was ready to make a call. The user then lifted the receiver and the "Signal Generator" was connected to the exchange. The exchange was then in control of the "Signal Generator" and signalled when it was ready to accept the call. The levers then remain untouched and could be made to call the same number again just by turning the crank and lifting the receiver - probably the first "Last Number Redial" facility on a telephone!

The levers could also be locked (inside the telephone) in any combination of numbers so only one number could be dialled. This functionality would probably be used in public areas were only one number dialled was required e.g. a Taxi company number.

The telephones below were the models used by the GPO. Earlier models were in the typical American fiddleback style with the four levers fitted at the top and a metal plate around the levers with the inscriptions "Automatic Telephone" and "The Automatic Machine Telephone Co. Ltd".