Transmission control system

Claim 1

A HYDRAULIC SHIFTING INSTALLATION FOR THE SHIFTING ELEMENTS OF CHANGE-SPEED TRANSMISSIONS, ESPECIALLY FOR HYDRODYNAMIC COMBINATION TRANSMISSIONS OF VEHICLES, COMPRISING: PRESSURE SUPPLY MEANS FOR PRODUCING A HYDRAULIC PRESURE MEDIUM, CHANGE-SPEED GEAR MEANS HAVING A PLURALITY OF ENGAGABLE MEANS FOR PRODUCING THE INDIVIDUAL SPEEDS THEREOF, AND SHIFTING MEANS SELECTIVELY CONNECTING THE PRESSURE MEDIUM SUPPLY MEANS WITH THE ENGAGABLE MEANS AND RELIEVING THE PRESSURE MEDIUM FROM PREVIOUSLY ENGAGED ENGAGABLE MEANS FOR ENGAGING THE INDIVIDUAL SPEEDS OF A CHANGE-SPEED GEAR MEANS WHILE MAINTAINING TRANSMISSION OF TORQUE DURING A CHANGE IN SPEED WITHIN SAID CHANGE-SPEED GEAR MEANS, SAID SHIFTING MEANS INCLUDING SPEED SELECTOR VALVE MEANS, AND CONNECTING MEANS OPERATIVELY CONNECTING SAID SUPPLY MEANS WITH SAID SPEED SELECTOR VALVE MEANS AND HAVING TWO CONTROL MEANS STRUCTURALLY INTERRELATED FOR ONLY ALTERNATE ACTUATION, ONE OF SAID TWO CONTROL MEANS BEING IN HYDRAULIC COMMUNICATION BY WAY OF SAID SPEED SELECTOR VALVE MEANS WITH THE ENGAGABLE MEANS FOR THE SPEED TO BE ENGAGED AND THE OTHER OF SAID TWO CONTROL MEANS BEING IN HYDRAULIC COMMUNICATION WITH THE ENGAGABLE MEANS OF THE PREVIOUSLY ENGAGED SPEED, MEANS FOR COUPLING SAID TWO CONTROL MEANS WITH EACH OTHER AGAINST THE EFFECT OF ELASTIC MEANS IN SUCH A MANNER THAT THE PRESSURE MEDIUM SUPPLY TO THE RESPECTIVELY ACTED UPON CONTROL MEANS TAKES PLACE DURING CHANGE IN SPEED IN DEPENDENCE ON THE DISCHARGING OF THE CONTROL MEANS TO BE RELIEVED, SAID CONTROL MEANS FORMED BY TWO PISTONS OF SUBSTANTIALLY IDENTICAL EFFECTIVE DIMENSIONS AND ARRANGED AXIALLY PARALLEL TO ONE ANOTHER , AND SAID COUPLING MEANS INCLUDING YOKE MEANS, AND FLOW-CONTROL VALVE MEANS IN SAID CONNECTING MEANS FOR CONTROLLING THE SUPPLY OF PRESSURE MEDIUM TO SAID PISTON MEANS, AND SAID YOKE MEANS BEING SUPPORTED ON SAID FLOW-CONTROL MEANS, AND FURTHER CONNECTING MEANS OPERATIVELY CONNECTING SAID YOKE MEANS WITH SAID FLOW-CONTROL MEANS INCLUDING INTERMEDIATE LINKAGE MEANS AND MEANS FOR INFLUENCING SAID INTERMEDIATE LINKAGE MEANS IN DEPENDENCE ON THE VEHICLE VELOCITY.