Aerial tramway system

Claim 1

A CARRIAGE FOR USE IN SUSPENDING A SELF-PROPELLED VEHICLE ON AN AERIAL TRAMWAY SYSTEM INCLUDING SPACED TOWERS WITH LENGTHS OF SUSPENSION CABLE STRUNG BETWEE THEM COMPRISING: AN ELONGATE SUPPORT STRUCTURE EXTENDING IN THE DIRECTION OF TRAVEL OF SAID CARRIAGE; A PLURALITY OF DRIVE WHEELS MOUNTED IN FORE AND AFT SPACED RELATION OF DRIVE STRUCTURE TO ENGAGE THE UPPER SIDE OF SAID CABLE TO SUPPORT AND PROPEL SAID VEHICLE; MOTOR MEANS CARRIED BY SAID STRUCTURE IN DRIVING ENGAGEMENT WITH SAID DRIVE WHEEL; PRESSURE ROLLERS MOUNTED ON SAID STRUCTURE OPERATIVE TO YIELDABLY PRESSURALLY ENGAGE THE UNDERSIDE OF SAID CABLE TO PRODUCE A GREATER TRACTION, CABLE-GRIPPING ACTION BETWEEN THE DRIVE WHEELS AND THE ROLLERS, SAID PRESSURE ROLLERS OPERATIVE TO RETRACT AWAY FROM SAID CABLE AGAINST THE PRESSURE URGING THEM TOWARDS SAID TRACK; A SOURCE OF FLUID UNDER PRESSURE; FLUID MOTOR MEANS CONNECTED TO SAID ROLLER TO URGE THEM INTO ENGAGEMENT WITH SAID CABLE;