Gear shifting mechanism

Claim 1

A CONTROL SYSTEM FOR THE OPERATION OF A POWER TRANSMISSION INCLUDING A PRIME MOVER, REVERSIBLE GEARING AND A DRIVEN SHAFT, SAID CONTROL SYSTEM COMPRISING AN ARM SHIFTABLE TO ESTABLISH THE DESIRED FORWARD, NEUTRAL OR REVERSE OPERATION OF SAID POWER TRANSMISSION, A MANUALLY OPERABLE SELECTOR SWITCH HAVING FORWARD, NEUTRAL AND REVERSE POSITIONS, A HIGH SPEED REVERSIBLE ELECTRIC MOTOR, A SOURCE OF POWER FOR SAID MOTOR, A CONTROL CIRCUIT FOR SAID MOTOR, A SPEED REDUCER DRIVEN BY SAID MOTOR, A LOW SPEED POWER OUTPUT SHAFT IN SAID SPEED REDUCER, AN OPERATING ARM FIXEDLY ATTACHED TO SAID POWER OUTPUT SHAFT, A MOTION TRANSMITTING LINK CONNECTING SAID SHIFTABLE AND OPERATING ARMS, A PLURALITY OF AXIALLY SPACED CAM MEANS ON SAID POWER OUTPUT SHAFT, SAID CAM MEANS CONTROLLING THE NEUTRAL, FORWARD AND REVERSE OPERATION OF SAID MOTOR, A SEPARATE ROTATABLY ADJUSTABLE MEMBER DISPOSED ADJACENT EACH OF SAID CAM MEANS, A PAIR OF NORMALLY CLOSED SWITCHES MOUNTED ON EACH OF SAID ROTATABLY ADJUSTABLE MEMBERS, EACH OF SAID SWITCHES INCLUDING FIXED AND MOVABLE ELECTRICAL CONTACTS, A CAM FOLLOWER MOUNTED ON EACH OF SAID MOVABLE CONTACTS, AND ELECTRICAL CONNECTIONS PLACING SAID SWITCHES IN SAID CONTROL CIRCUIT WHEREBY THE MANUAL SHIFTING OF SAID SELECTOR SWITCH FROM ONE POSITION TO ANOTHER SERVES TO CLOSE SAID CONTROL CIRCUIT AND ENERGIZE SAID MOTOR TO EFFECT ROTATION OF SAID POWER OUTPUT SHAFT AND MOVEMENT OF SAID SHIFTABLE ARM UNTIL SUCH TIME AS ONE OF SAID CAM MEANS EFFECTS THE OPENING OF ONE OF SAID SWITCHES TO BREAK THE CONTROL CIRCUIT AND THEREBY DEENERGIZE SAID MOTOR WHEN SAID SELECTED GEAR SHIFTING OPERATION HAS BEEN COMPLETED, THE SEPARATE SWITCHES OF EACH PAIR CONTROLLING THE OPPOSITE DIRECTIONS OF ROTATION OF SAID MOTOR, SAID CAM MEANS ACTUATING ONE OF SAID SWITCHES IMMEDIATELY AFTER ACTUATING THE OTHER SAID SWITCH TO PRECLUDE OVERRUN OF THE SHAFT.