Power transmission

Claim 1

IN A POWER TRANSMISSION INCLUDING AN HYDRAULIC TORQUE CONVERTER HAVING AN IMPELLER ARRANGED FOR CONNECTION TO A POWER SOURCE, A TURBINE AND A STATOR COOPERABLY RELATED TO FORM A TOROIDAL CIRCUIT, A SHAFT CONNECTED TO THE TURBINE, AN HYDRAULICALLY ACTUATED, FRICTION PLATE, LOCKUP CLUTCH ENGAGEABLE TO CONNECT THE IMPELLER AND TURBINE TO PROVIDE DIRECT DRIVE TO THE TURBINE SHAFT, A PLURALITY OF CONSTANT MESH, GEAR TRAINS HAVING RESPECTIVELY DIFFERENT GEAR RATIOS AND CONNECTION WITH THE TURBINE SHAFT AND A LOAD SHAFT, AND A PLURALITY OF HYDRAULICALLY ACTUATED, FRICTION PLATE CLUTCHES ASSOCIATED WITH THE GEAR TRAINS, THE COMBINATION OF AN HYDRAULIC SYSTEM INCLUDING A PRESSURE LIQUID SOURCE, THE TOROIDAL CIRCUIT, LOCKUP AND GEAR TRAIN CLUTCHES, A SELECTOR VALVE MOVABLE TO CONNECT THE PRESSURE LIQUID SOURCE WITH A SELECTED GEAR TRAIN CLUTCH, MEANS SHIFTABLE BETWEEN POSITIONS DISCONNECTING AND CONNECTING THE PRESSURE LIQUID SOURCE FROM AND TO THE LOCKUP CLUTCH TO PROVIDE CONVERTER AND DIRECT DRIVE THROUGH THE TRANSMISSION, RESPECTIVELY, COMPRISING A LOCKUP VALVE, SPRING MEANS ACTING AGAINST ONE END OF AND BIASING THE LOCKUP VALVE TO THE POSITION DISCONNECTING THE PRESSURE LIQUID SOURCE FROM THE LOCKUP CLUTCH AT ONE DETERMINED SPEED OF THE TURBINE SHAFT, LIQUID PRESSURE GENERATING MEANS WHOSE PRESSURE OUTPUT IS RESPONSIVE TO TURBINE SHAFT SPEED, AND AN UNCONTROLLED PASSAGE CONNECTING WITH THE OUTPUT OF THE LIQUID PRESSURE GENERATING MEANS FOR SUPPLYING PRESSURE TO THE OPPOSITE END OF THE LOCKUP VALVE TO MOVE THE SAME TO THE POSITION CONNECTING THE PRESSURE LIQUID SOURCE TO THE LOCKUP CLUTCH AT A HIGHER TURBINE SHAFT SPEED.