Hydromechanical transmission with countershaft gearing

Claim 1

AN INFINITELY VARIABLE SPEED HYDROMECHANICAL POWER TRANSMISSION CAPABLE OF TRANSMITTING ROTARY POWER IN SPEED RATIOS INCLUDING OVERDRIVE FORWARD AND OVERDRIVE REVERSE COMPRISING, IN COMBINATION: (A) AN INPUT SHAFT AND AN OUTPUT SHAFT, (B) A MULTI-CYLINDER HYDRAULIC PUMP DRIVEN BY SAID INPUT SHAFT, (C) SAID PUMP HAVING A FORCE REACTION SHAFT DRIVEN THEREBY, (D) A SHIFTABLE CHANGE-SPEED GEAR MECHANISM HAVING A COUNTERSHAFT ENGAGEABLE FOR DRIVE RELATION WITH SAID OUTPUT SHAFT, (E) SAID FORCE REACTION SHAFT CONNECTED IN DRIVE RELATION TO SAID COUNTERSHAFT, (F) A MULTI-CYLINDER HYDRAULIC MOTOR HYDRAULICALLY INTERCONNECTED OPERABLY WITH SAID PUMP, SAID MOTOR BEING DRIVINGLY CONNECTED TO SAID COUNTERSHAFT, (G) SAID PUMP HAVING AN ANGULARLY DISPLACEABLE SWASHPLATE HYDRAULICALLY MOVABLE IN TWO QUADRANTS AND SERVO-CONTROL THEREFOR FOR CONTROLLING THE FLUID DISPLACEMENT OF SAID PUMP, AND (H) AID MOTOR HAVING AN ANGULARLY DISPLACEABLE SWASHPLATE HYDRAULICALLY MOVABLE IN TWO QUADRANTS AND SERVO-CONTROL THEREFOR FOR CONTROLLING THE FLUID DISPLACEMENT OF SAID MOTOR WHEREBY SAID GEAR MECHANISM IS SELECTIVELY OPERABLE TO INCREASE THE PROPORTION OF POWER TRANSMITTED MECHANICALLY TO SAID OUTPUT SHAFT AND CORRESPONDINGLY REDUCE THE PROPORTION OF POWER TRANSMITTED HYDRAULICALLY TO SAID OUTPUT SHAFT AT A SELECTED OVERALL SPEED RANGE THEREBY INCREASING THE POWER EFFICIENCY TRANSMITTED THROUGH SAID TRANSMISSION.