Semi-automatic transmission

Claim 1

IN A TRANSMISSION FOR AN INTERNAL COMBUSTION ENGINE HAVING A MANIFOLD VACUUM SOURCE AND HAVING DRIVING AND DRIVEN MEANS AND MEANS FOR SELECTIVELY PROVIDING A PLURALITY OF FORWARD SPEED RATIOS, AN OVEDRIVE PLANETARY GEAR UNIT, COMPRISING; SUN AND RING GEARS AND A PLANETARY GEAR IN MESH WITH THE SUN AND RING GEAR AND HAVING A PLANETARY GEAR CARRIER, SAID CARRIER BEING DRIVINGLY CONNECTED WITH SAID DRIVING SHAFT AND SAID RING GEAR BEING CONNECTED WITH SAID DRIVEN MEANS OF SAID TRANSMISSION, A ONE-WAY CLUTCH MEANS BETWEEN SAID SUN AND PLANET CARRIER FOR PROVIDING A ONE-WAY DIRECT FORWARD DRIVE THROUGH SAID PLANETARY GEAR UNIT, A FRICTION BRAKE FOR SAID SUN GEAR FOR COMPLETING AN OVERDRIVE FORWARD DRIVE THROUGH THE PLANETARY GEAR UNIT, FLUID PRESSURE OPERATED MEANS EFFECTIVE TO SELECTIVELY ENGAGE SAID FRICTION BRAKE, MEANS PROVIDING A SOURCE OF FLUID PRESSURE FOR SAID BRAKE VARYING WITH BOTH THE SPEED AND MANIFOLD VACUUM SOURCE OF SAID ENGINE, ELECTRICALLY OPERATED SOLENOID VALVE MEANS CONTROLLING THE COMMUNICATION OF THE FLUID SOURCE WITH SAID FLUID PRESSURE OPERATED MEANS, AND ELECTRICAL MEANS RESPONSIVE TO THE SPEED AND TO THE MANIFOLD VACUUM SOURCE OF SAID ENGINE OF SAID DRIVEN MEANS FOR ENERGIZING SAID SOLENOID VALVE MEANS AT VARIABLE PREDETERMINED SPEEDS.