Locking Switch - Transfer, 3-position.
This file was derived from:
 IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (5).svg
IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (12).svg
(in English) (1993)  315-1975 - IEEE Standard American National Standard Canadian Standard Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters), IEEE, p. 61  DOI:  10.1109/IEEESTD.1993.93397. ISBN:  0738109479.
Michel Bakni