Two position low pitch stop

Claim 1

FOR AN AERONAUTICAL PROPELLER HAVING VARIABLE PITCH BLADES AND MEANS INCLUDING A HIGH PITCH CHAMBER, A LOW PITCH CHAMBER AND A PITCH CHANGE MOTOR FOR VARYING THE PITCH OF SAID BLADES, A DOME MOUNTED FORWARD OF SAID BLADES ABOUT THE ROTATIONAL AXIS OF SAID PROPELLER, A RETRACTABLE CAM IN SAID DOME HAVING A FIRST SHOULDER AND A SECOND SHOULDER SPACED FROM SAID FIRST SHOULDER EACH EXTENDING LATERALLY FROM SAID LONGITUDINAL AXIS AND EACH ADAPTED TO ENGAGE SAID PITCH CHANGE MOTOR, A SOURCE OF PRESSURIZED FLUID AND A DRAIN, CONTROL MEANS INCLUDING FLUID CONNECTING MEANS INTERCONNECTING SAID HIGH PITCH CHAMBER AND SAID LOW PITCH CHAMBER WITH SAID SOURCE AND SAID DRAIN FOR EFFECTUATING PITCH CHANGE MOVEMENT OF SAID BLADES AND ADAPTED TO POSITION SAID MOTOR TO ABUT AGAINST SAID 1ST AND 2ND SHOULDERS, NORMALLY INOPERATIVE PITCH LOCK MEANS INCLUDING INDEPENDENT COORDINATING MEANS FOR ENGAGING SAID BLADES AND PREVENTING THEM TO MOVE TOWARD A LOW PITCH, MEANS FOR ALLOWING SAID CAM TO RETRACT SO THAT THE PITCH CHANGE MOTOR WILL PAS OVER SAID FIRST SHOULDER SO AS TO ENGAGE SAID SECOND SHOULDER AND THEN TO ALLOW SAID CAM TO RETRACT FURTHER SO THAT THE PITCH CHANGE MOTOR WILL PASS OVER SAID SECOND SHOULDER WHEREBY SAID BLADES WILL BE POSITIVELY RESTRAINED AT A FIRST PREDETERMINED BLADE ANGLE AND THEN A SECOND PREDETERMINED BLADE ANGLE AND THEN ALLOWED TO GO TO A BLADE ANGLED BEYOND SAID SECOND PREDETERMINED BLADE ANGLE, SAID MEANS INCLUDING A SERVO PISTON OPERATIVELY CONNECTED TO SAID CAM, A FLUID RECEIVING CHAMBER ADJACENT SAID SERVO PISTON RECEIVING FLUID FROM SAID SOURCE, MEANS FOR REGULATING THE FLUID PRESSURE IN SAID CHAMBER AFTER EFFECTUATING MOVEMENT OF SAID SERVO PISTON TO ALLOW SAID CAM TO RETRACT AND ADDITIONAL MEANS RESPONSIVE TO SAID PITCH LOCK MEANS FOR FURTHER REGULATING THE PRESURE IN SAID CHAMBER FOR EFFECTUATING FURTHER MOVEMENT OF SAID SERVO PISTON FOR ALLOWING SAID CAM TO RETRACT FURTHER.