Planetary transmission

Claim 1

FOR USE IN MULTISTAGE TRANSMISSIONS, A TRANSMISSION UNIT TO SERVE AS AN INPUT STAGE THEREOF TO PROVIDE A SELECTIONOF FOUR DIFFERENT SPEED RATIOS COMPRISING A PLURALITY OF ANNULAR SECTIONS ADAPTED TO BE STACKED IN ABUTTING RELATION TO EACH OTHER AND TO AN ADJACENT OUTPUT UNIT TO FORM A HOUSING, A PLANETARY GEAR TRAIN IN SAID HOUSING INCLUDING A REACTION SUN GEAR AND THREE REACTION RING GEARS ROTATABLY MOUNTED IN SAID HOUSING AND ADAPTED TO BE SELECTIVELY BRAKED AGAINST ROTATION TO OBTAIN SAID FOUR DIFFERENT INPUT TO OUTPUT SPEED RATIO FROM SAID PLANETARY GEAR TRAIN, SAID PLANETARY GEAR TRAIN FURTHER INCLUDING FOUR PLANETARY GEAR SETS SUPPORTED BY A COMMON CARRIER WITH PLANET GEARS OF TWO OF SAID SETS INTERMESHED, SAID SUN GEAR BEING INTERMESHED WITH GEARS OF ONE OF SAID TWO SETS AND SAID REACTION RING GEARS BEING INTERMESHED WITH GEARS OF OTHER SETS, COAXIAL INPUT AND OUTPUT SHAFTS CONNECTED IN TORQUE TRANSMITTING RELATION BY SAID PLANETARY GEAR TRAIN, ANNULAR BRAKE CYLINDERS DEFINED BETWEEN SAID ANNULAR SECTIONS SO AS TO PROVIDE A BRAKE CYLINDER FOR EACH REACTION GEAR, ANNULAR PISTONS IN SAID CYLINDERS, AND MEANS CONNECTING EACH PISTON WITH A REACTION GEAR WHEREBY THE LATTER IS BRAKED AGAINST MOVEMENT RELATIVE TO THE HOUSING UPON ACTUATION OF THE PISTON IN THE CYLINDER.