Passage: The sales network has been expanded continuously since 1953. In 1963, the first branch was opened in Kägiswil with four employees. The process heat product line encompassing air heaters and blowers was developed a short time later. The existing location was expanded. All business activities were relocated to Switzerland in 1977. In-house motor fabrication was set up in 1979.

Question: When did the expansion of the sales network start?
1953.