Multiratio drive

Claim 1

A MULTIRATIO TRANSMISSION SYSTEM FROM A DRIVE TO A DRIVEN SHAFT COMPRISING: A GEARBOX UNIT HAVING MEANS FOR SETTING THE SPEED RATIO THERETHROUGH TO A SELECTED ONE OF A NUMBER OF VALUES; A SPEED VARIATOR UNIT HAVING A CONTROL ELEMENT DISPLACEABLE OVER A RANGE OF POSITIONS FOR VARYING THE SPEED RATIO THERETHROUGH OVER A RANGE OF VALUES; MEANS OPERATIVELY CONNECTING BOTH UNITS SERIAL DRIVING RELATION WITH EACH OTHER BETWEEN SAID DRIVE AND DRIVEN SHAFTS; A POSITIONAL SERVO-MOTOR INCLUDING A CYLINDER MEMBER AND A PISTON MEMBER SLIDABLE WITH RESPECT TO EACH OTHER; MEANS CONNECTING ONE OF SAID MEMBERS TO SAID VARIATOR CONTROL ELEMENT; A POWER FLUID CIRCUIT HAVING A SOURCE OF PRESSURE FLUID AND AN EXHAUST; A PAIR OF INLET PORTS OPENING INTO RESPECTIVE END OF SAID CYLINDER MEMBER AND CONNECTED TO SAID PRESSURE SOURCE; A SERIES OF EXHAUST PORTS OPENING INTO SAID CYLINDER AT POINTS SPACED ALONG THE AXIAL LENGTH THEREOF AND INDIVIDUALLY SEALABLE BY SAID PISTON MEMBER; EXHAUST PASASAGES CONNECTING SAID EXHAUST PORTS INDIVIDUALLY WITH SAID EXHAUST; VALVES SELECTIVELY CONTROLLING SAID EXHAUST PASSAGES TO SELECT THE EQUILIBRIUM POSITION ASSUMED BY SAID PISTON MEMBER RELATIVE TO SAID CYLINDER MEMBER FROM A SERIES OF POSITIONS AS DETERMINED BY THE POSITIONS OF SAID EXHAUST PORTS AND THEREBY SELECT THE VARIATOR SPEED RATIO FROM A CORRESPONDING NUMBER OF DISCRETE VALUES WITHIN ITS SAID RANGE; A COMMON EXHAUST MANIFOLD HAVING ONE END CONNECTED WITH ALL SAID EXHAUST PASSAGES AND ANOTHER END CONNECTED WITH SAID EXHAUST OF THE FLUID CIRCUIT; A CUT-OFF VALVE POSITIONED IN SAID MANIFOLD; A BYPASS LINE SHUNTING SAID CUT-OFF VALVE; AND AN ADJUSTABLE FLOW REGULATED ORIFICE IN SAID BYPASS LINE FOR CONTROLLING THE VELOCITY OF RELATIVE DISPLACEMENT OF SAID PISTON AND CYLINDER MEMBERS.