Hydrostatic transmission

Claim 1

IN COMBINATION (A) A VEHICLE HAVING MOTION IMPARTING MEANS; (B) A WORK-PERFORMING MOVABLE IMPLEMENT CARRIED BY THE VEHICLE, SAID IMPLEMENT BEING OF THE TYPE THAT DURING CERTAIN OPERATIONS REQUIRES MOVEMENT RELATIVELY TO THE VEHICLE AS WELL AS MOVEMENT OF THE VEHICLE; (C) A PRIME MOVER FOR THE VEHICLE; (D) FIRST AND SECOND HYDRAULIC MOTORS CONNECTED, RESPECTIVELY, WITH THE MOTION-IMPARTING MEANS AND THE IMPLEMENT; (E) A PAIR OF FIXED DISPLACEMENT HYDRAULIC PUMPS CONNECTED IN DRIVEN RELATION WITH THE PRIME MOVER; (F) RESERVOIR MEANS; (G) A PROPULSION CIRCUIT INTERCONNECTING THE RESERVOIR MEANS, THE FIRST PUMP AND THE FIRST MOTOR AND INCLUDING A FIRST CONTROL VALVE INTERPOSED BETWEEN THE FIRST PUMP AND THE FIRST MOTOR FOR SELECTIVELY CONNECTING AND DISCONNECTING THESE TWO UNITS; (H) AN IMPLEMENT CIRCUIT INTERCONNECTING THE RESERVOIR MEANS, THE SECOND PUMP AND THE SECOND MOTOR AND INCLUDING A SECOND CONTROL VALVE INTERPOSED BETWEEN THE SECOND PUMP AND SECOND MOTOR FOR SELECTIVELY CONNECTING AND DISCONNECTING THESE TWO UNITS; (I) FIRST UNLOADING MEANS ASSOCIATED WITH THE PROPULSION CIRCUIT FOR UNLOADING THE FIRST PUMP WHEN IT IS DISCONNECTED FROM THE FIRST MOTOR; (J) SECOND UNLOADING MEANS ASSOCIATED WITH THE IMPLEMENT CIRCUIT FOR UNLOADING THE SECOND PUMP WHEN IT IS DISCONNECTED FROM THE SECOND MOTOR; AND (K) VALVE MEANS CONNECTED WITH THE IMPLEMENT AND PROPULSION CIRCUITS AND ARRANGED TO SELECTIVELY CONNECT ONE OF THE MOTORS WITH ITS CONTROL VALVE AND WITH THE OTHER CIRCUIT.