Patent ID: 6908277

Claim:
Speed governor for a pneumatic rotation motor having a rotor ( 11 ) and a stator ( 10 ) with a pressure air inlet passage ( 15 ), comprising an inlet valve ( 16 ; 56 ) with a flow controlling valve element ( 18 ; 58 ) disposed in said inlet passage ( 15 , 15 ′), and a speed responsive activating device ( 24 ; 54 ) operatively connected to said inlet valve ( 16 ; 58 ), wherein: said activating device ( 24 ; 54 ) comprises a pneumatic pilot circuit ( 21 , 20 , 25 ; 72 , 70 , 77 , 78 ) for governing the operation of said inlet valve ( 16 ; 56 ), and said pilot circuit ( 21 , 20 , 25 ; 72 , 70 , 77 , 78 ) comprises: an activating surface ( 20 ; 70 ) on said valve element ( 18 ; 58 ), a restricted pressure air supply opening ( 21 ; 72 ) communication with said activating surface ( 20 ; 70 ), an air bleed-off valve ( 24 ; 54 )communicating with said activating surface ( 20 ; 70 ) and comprising an electromagnetic actuator ( 27 ; 76 ), and a generator ( 30 ) driven by said motor and delivering a motor speed responsive output voltage, said generator ( 30 ) is connected to said electro-magnetic actuator ( 27 ; 76 ) for accomplishing operation of said bleed-off valve ( 24 ; 54 ) and said inlet valve ( 16 ; 56 ) in response to said output voltage.