Speed maintaining mechanism

Claim 1

AN ENGINE SPEED CONTROLLING SYSTEM COMPRISING, A POWER SERVO ADAPTED FOR CONNECTION TO AN ENGINE SPEED CONTROL MEMBER AND A PILOT VALVE ASSEMBLY HAVING A MOVABLE PILOT VALVE MEMBER OPERATING TO CONTROL FLUID PRESSURE DELIVERED TO SAID SERVO, SAID PILOT VALVE ASSEMBLY INCLUDING SPEED SETTING MEANS ACTING IN A DIRECTION ON SAID PILOT VALVE MEMBER TENDING TO INCREASE ENGINE SPEED AND SPEED SENSING AND FORCE SUPPLYING MEANS CONNECTED TO ACT ON SAID PILOT VALVE MEMBER IN THE OPPOSITE DIRECTION TO SAID SPEED SETTING MEANS, SPEED RESPONSIVE MEANS ADAPTED TO TRANSMIT SPEED SIGNALS TO SAID SPEED SENSING AND FORCE SUPPLYING MEANS, A SOURCE OF FLUID PRESSURE FOR SAID SERVO, MEANS CONNECTING SAID SOURCE TO SAID SERVO THROUGH SAID PILOT VALVE ASSEMBLY, A FLUID PRESSURE SHUTOFF VALVE IN SAID CONNECTING MEANS, AN ELECTRIC CIRCUIT AND SOURCE OF ENERGY THEREFOR, AND ELECTROMAGNETIC MECHANISM IN SAID CIRCUIT AND OPERATIVE WHEN ELECTRICALLY ENERGIZED TO OPEN SAID FLUID PRESSURE SHUTOFF VALVE AND HOLD IT OPEN, A NORMALLY OPEN SWITCH IN SAID CIRCUIT CONNECTED FOR OPERATION TO THE CLOSING POSITION BY SAID SPEED DETECTING AND FORCE SUPPLYING MEANS WHEN SAID SPEED DETECTING AND FORCE SUPPLYING MEANS IS MOVED TO A PREDETERMINED POSITION IN OPPOSITION TO THE ACTION ON SAID SPEED SETTING MEANS IN RESPONSE TO SIGNALS RECEIVED FROM SAID SPEED RESPONSIVE MEANS.