Hydraulically operated power transmission systems and vehicles incorporating such systems

Claim 1

A HYDRAULICALLY OPERATED POWER TRANSMISSION SYSTEM OF THE KIND COMPRISING A SWASH PLATE ACTUATED MULTIPLE-PISTON PUMP ADAPTED TO SUPPLY HYDRAULIC PRESSURE MEDIUM TO A SIMILAR SWASH PLATE ACTUATED MULTIPLE-PISTON MOTOR, THE PUMP AND THE MOTOR EACH INCLUDING A HOUSING FORMED WITH A PLURALITY OF CHAMBERS WHICH RECEIVE THEIR RESPECTIVE PISTONS, THE PUMP HOUSING AND THE MOTOR HOUSING EACH BEING ROTATABLE ABOUT AN AXIS, SAID SWASH PLATES BEING TURNABLE ABOUT FURTHER AXES WHICH INTERSECT AND ARE SUBSTANTIALLY PERPENDICULAR TO THE FIRST-MENTIONED AXIS TO VARY THE TRANSMISSION RATIO OF THE SYSTEM, COUPLING RODS, SAID SWASH PLATES BEING ARRANGED TO BE TURNABLE WITH THE AID OF SAID COUPLING RODS WHICH ARE SITUATED BETWEEN SAID SWASH PLATES, THE CONNECTION POINTS OF SAID COUPLING RODS TO SAID SWASH PLATES BEING SITUATED AT A DISTANCE FROM SAID FIRST-MENTIONED AXIS WHEN VIEWED IN A DIRECTION PERPENDICULAR TO A PLANE CONTAINING SAID FIRST-MENTIONED AXIS AND ALSO SAID SECOND-MENTIONED AXES ABOUT WHICH THE SWASH PLATES ARE TURNABLE FOR VARYING THE TRANSMISSION RATIO, A CONTROL SHAFT TURNABLE ABOUT ITS LONGITUDINAL AXIS WHICH EXTENDS AT LEAST SUBSTANTIALLY PARALLEL TO THE AXES ABOUT WHICH SAID SWASH PLATES ARE TURNABLE FOR VARYING THE TRANSMISSION RATIO, SAID COUPLING RODS BEING COUPLED WITH SAID CONTROL SHAFT, THE ARRANGEMENT BEING SUCH THAT SAID COUPLING RODS ARE PIVOTABLE WITH RESPECT TO SAID CONTROL SHAFT ABOUT PIVOTAL AXES AND A LINE JOINING THE LONGITUDINAL AXES OF THE CONTROL SHAFT TO THE PIVOTAL AXIS OF THE PUMP SWASH PLATE COUPLING ROD IS INCLINED AT SUBSTANTIALLY 90* TO A SIMILAR PERPENDICULAR LINE JOINING THE LONGITUDINAL AXIS OF THE CONTROL SHAFT TO THE PIVOTAL AXIS OF THE MOTOR SWASH PLATE COUPLING ROD.