Noun
Strowger switch (plural Strowger switches)
A type of stepping switch able to select on two axes, formerly widely used in telephone exchanges.
Fixed line services In the 1980s there was a shortage of local line capacity on the existing crossbar exchange, which itself had replaced the relay and Strowger switch exchanges and a modern digital System/X switch was installed. Source: Internet
For most of the twentieth century a " Strowger switch " or a "crossbar switch" referred to an individual piece of mechanical equipment making up part of an exchange. Source: Internet