Control means for epicyclic power transmission mechanisms

Claim 1

IN AN EPICYCLIC POWER TRANSMISSION MECHANISM COMPRISING AN INPUT SHAFT, AN OUTPUT SHAFT, FIRST AND SECOND EPICYCLIC DRIVING ELEMENTS WHICH CAN SELECTIVELY BE COUPLED TO SAID INPUT SHAFT TO PROVIDE ALTERNATIVE EPICYLIC DRIVE PATHS THROUGH SAID MECHANISM BETWEEN SAID SHAFTS, AND A REACTION PINION WHICH CAN BE CONTROLLED TO PROVIDE ALTERNATIVE DRIVE RATIOS: CONTROL MEANS COMPRISING A DRIVING CLUTCH MEMBER OPERATIVELY CONNECTED TO SAID INPUT SHAFTS FIRST AND SECOND DRIVEN CLUTCH MEMBERS FOR ALTERNATIVE FRICTIONAL CLUTCHING ENGAGEMENT WITH SAID DRIVING CLUTCH MEMBER AND ADAPTED TO TRANSMIT THE DRIVE TO SAID FIRST AND SECOND DRIVING ELEMENTS RESPECTIVELY, FIRST AND SECOND OPPOSITELY ACTING FLUID-OPERATED PISTON FOR IMPARTING OPPOSITE AXIAL MOVEMENT TO ONE OF SAID DRIVE CLUTCH MEMBERS, A THIRD CLUTCH MEMBER ASSOCIATED WITH SAID REACTION PINION, A FOURTH CLUTCH MEMBER ASSOCIATED WITH SAID AN EPICYCLIC ELEMENT OF THE MECHANISM AND ARRANGED FOR FRICTIONAL CLUTCHING ENGAGEMENT WITH SAID THIRD CLUTCH MEMBER, THIRD AND FOURTH FLUID-OPERATED PISTON FOR ACTUATING SAID THIRD CLUTCH MEMBER, ONE OF THE LAST-MENTIONED TWO PISTONS BEING PERMANENTLY CONNECTED IN THE FLUID SENSE WITH ONE OF THE FIRST-MENTIONED TWO OPPOSITELY ACTING PISTONS, AND A FIFTH FLUID-OPERATED PISTON FOR CAUSING AXIAL MOVEMENT OF SAID DRIVING CLUTCH MEMBER INTO CLUTCHING ENGAGMENT WITH THE OTHER OF SAID DRIVEN CLUTCH MEMBERS, AGAINST SPRING LOADING, AND WHEREIN THE FIRST FLUID OPERATED PISTON, WHICH MOVES THE ONE DRIVEN CLUTCH MEMBERS TOWARDS AND INTO CLUTCHING ENGAGEMENT WITH THE DRIVING CLUTCH MEMBER, IS ARRANGED TO EXERT A FORCE WHICH OVERCOMES THE FORCE EXERTED BY SAID FIFTH PISTON, WHEREBY TO EFFECT SIMULTANEOUS DISENGAGEMENT OF THE DRIVING CLUTCH MEMBER FROM SAID OTHER DRIVEN CLUTCH MEMBER.