Series pathfinding and setting via same conductor in tandem crosspoint switching netwrk

Claim 1

IN A COMMUNICATION SWITCHING SYSTEM, A FIRST SET OF TERMINALS, A SECOND SET OF TERMINALS, A PLURALITY OF SWITCHING STAGES ARRANGED IN TANDEM FOR SELECTIVELY ELECTRICALLY CONNECTING TERMINALS OF THE FIRST SET WITH TERMINALS OF THE SECOND SET, EACH OF SAID STAGES COMPRISING A PLURALITY OF RELAYS ARRANGED IN A COORDINATE ARRAY, A UNIDIRECTIONAL DEVICE INDIVIDUAL TO EACH OF SAID RELAYS AND CONNECTED IN SERIES WITH A WINDING THEREOF, AT THE COORDINATE POINTS OF EACH OF SAID ARRAYS, INTERSTAGE LINKS INTERCONNECTING ADJACENT STAGES, AND FIRST AND SECOND SETS OF END LINKS CONNECTING THE END STAGES TO THE CORRESPONDING TERMINALS OF THE FIRST AND SECOND SETS RESPECTIVELY, EACH LINK HAVING A PLURALITY OF CONDUCTORS INCLUDING AN OPERATE CONDUCTOR, SAID UNIDIRECTIONAL DEVICES IN SERIES WITH A WINDING OF EACH RELAY BEING CONNECTED BETWEEN THE OPERATE CONDUCTORS OF A LINK EACH SIDE OF THE STAGE, SO THAT BETWEEN A TERMINAL OF THE FIRST SET AND A TERMINAL OF THE SECOND SET THERE IS A SERIES PATH INCLUDING THE WINDING AND UNIDIRECTIONAL DEVICE OF ONE COORDINATE POINT RELAY OF EACH OF SAID STAGES AND THE OPERATE CONDUCTORS OF THE ASSOCIATED LINKS; LINK-BUSY MEANS TO BLOCK THE CIRCUIT PATH IN THE OPERATE CONDUCTOR OF EACH BUSY INTERSTAGE LINK AND EACH BUSY END LINK OF THE SECOND SET, MEANS TO APPLY A FIRST MARKING POTENTIAL TO THE OPERATE CONDUCTOR OF A SELECTED TERMINAL OF THE FIRST SET, SCANNING MEANS INCLUDING DE-