Transmission improvement in party-line telphone systems

Claim 1

IN A PARTY-LINE TELEPHONE SYSTEM FOR THE TRANSMISSION OF VOICE SIGNALS, A CENTRAL OFFICE THAT INCLUDES A COMMON BATTERY FOR THE SUPPLY OF DIRECT CURRENT, A MAIN TRANSMISSION LINE CONNECTED TO SAID COMMON BATTERY AND HAVING DIRECT-CURRENT RESISTANCE, A PLURALITY OF SUBSCRIBER LOOPS EACH BRIDGED ACROSS SAID MAIN TRANSMISSION LINE AND EACH TERMINATED BY A TELEPHONE SET, EACH OF SAID SUBSCRIBER LOOPS HAVING A DIRECT-CURRENT RESISTANCES AND COMPRISING A NONLINEAR BRIDGE-LIFTING DEVICE THAT AUTOMATICALLY DIFFERENTIATES BETWEEN CURRENT LEVELS TO PERMIT THE TRANSMISSION OF SAID VOICE SIGNALS TO SAID TERMINATING TELEPHONE SET WHEN OFF-HOOK, AND SUBSTANTIALLY TO BLOCK SAID VOICE SIGNALS WHEN SAID TERMINATING TELEPHONE SET IS ON-HOOK, SAID BRIDGE-LIFTING DEVICES HAVING VARIOUS DIRECT-CURRENT RESISTANCES WHENEVER CURRENT FROM SAID COMMON BATTERY FLOWS IN SAID COMPRISED LOOPS, SAID BRIDGE-LIFTING DIRECT-CURRENT RESISTANCES BEING PROPORTIONED TO EQUALIZE THE SUMS OF SAID DIRECT-CURRENT RESISTANCES OF SAID COMPRISED LOOPS AND THE RESPECTIVE PORTIONS OF SAID DIRECT-CURRENT RESISTANCE OF SAID MAIN LINE BETWEEN SAID COMMON BATTERY AND SAID COMPRISED LOOPS TO EQUALIZE THE FLOW OF COMMON BATTERY CURRENT IN SAID COMPRISED LOOPS.