Transmission controls

Claim 1

IN A TRANSMISSION FOR AN AUTOMOTIVE VEHICLE HAVING A DRIVING ENGINE PROVIDED WITH A THROTTLE AND A THROTTLE ACTUATOR, THE COMBINATION OF A DRIVE SHAFT ADAPTED TO BE DRIVEN BY THE VEHICLE ENGINE, A DRIVEN SHAFT, GEARING INTERCONNECTING SAID SHAFTS AND ARRANGED TO SELECTIVELY PROVIDE LOW, INTERMEDIATE, AND HIGH SPEED POWER TRAINS BETWEEN SAID SHAFTS, A ONE-WAY BRAKE ENGAGEABLE TO ESTABLISH SAID LOW SPEED POWER TRAIN, A FLUID PRESSURE OPERATED FRICTION DEVICE ENGAGEABLE TO ESTABLISH SAID INTERMEDIATE SPEED POWER TRAIN, A SECOND FLUID PRESSURE OPERATED FRICTION DEVICE ENGAGEABLE TO ESTABLISH SAID HIGH SPEED POWER TRAIN, A SERVOMOTOR FOR EACH OF SAID FRICTION DEVICES, A SOURCE OF FLUID PRESSURE, A THROTTLE VALVE CONNECTED TO SAID SOURCE AND TO THE THROTTLE ACTUATOR FOR PROVIDING A PRESSURE THAT VARIES DIRECTLY WITH THE THROTTLE ACTUATOR POSITION, A HYDRAULIC GOVERNOR CONNECTED TO SAID SOURCE OF PRESSURE AND DRIVEN BY SAID DRIVEN SHAFT AND PROVIDING A GOVERNOR OUTPUT PRESSURE THAT INCREASES WITH DRIVEN SHAFT SPEED, FIRST AND SECOND SHIFT VALVES CONNECTED BETWEEN SAID SOURCE AND SAID SERVOMOTORS AND EACH HAVING END PORTIONS, PASSAGE MEANS DIRECTING FLUID PRESSURE FROM SAID THROTTLE VALVE AND SAID HYDRAULIC GOVERNOR TO OPPOSITE END PORTIONS OF THE RESPECTIVE SHIFT VALVES TO APPLY FLUID PRESSURE ON ONE END PORTION OF SAID SHIFT VALVES WHICH IS RESPONSIVE TO THE POSITION OF THE THROTTLE ACTUATOR AND FLUID PRESSURE RESPONSIVE TO THE SPEED OF THE VEHICLE ON THE OTHER END PORTION THEREOF TO CAUSE AUTOMATIC UPSHIFTING OF THE TRANSMISSION FROM LOW SPEED TO INTERMEDIATE SPEED TO HIGH SPEED, SAID SECOND SHIFT VALVE HAVING ONE POSITION CONNECTING SAID SOURCE OF FLUID PRESSURE TO THE SERVOMOTOR FOR SAID SECOND FRICTION DEVICE TO ESTABLISH SAID HIGH SPEED DRIVE RATIO AND AN OTHER POSITION INTERRUPTING THE CONNECTION TO THE SERVOMOTOR FOR SAID SECOND FRICTION DEVICE, SAID SECOND SHIFT VALVE HAVING TWO LANDS OF DIFFERENT DIAMETER THEREON DEFINING A DIFFERENTIAL AREA, SAID DIFFERENTIAL AREA BEING IN FLUID CONTACT WITH THE FLUID PRESSURE RESPONSIVE TO THE THROTTLE VALVE WHEN SAID SECOND SHIFT VALVE IS IN SAID ONE POSITION AND IN FLUID CONTACT WITH SAID SOURCE OF FLUID PRESSURE WHEN SAID SECOND SHIFT VALVE IS IN SAID OTHER POSITION TO PROVIDE AUTOMATIC DOWNSHIFTING OF HIGH SPEED TO INTERMEDIATE SPEED TO LOW SPEED WHEN THE THROTTLE VALVE IS IN AN OPEN POSITION AND PERMITTING AUTOMATIC DOWNSHIFTING OF HIGH SPEED DIRECTLY TO LOW SPEED WHEN THE THROTTLE VALVE IS IN ITS CLOSED POSITION.