Limit means for air jet responsive gyroscopes

In an attitude indicator for aircraft including a gyro which is contained in a housing having an air inlet opening and a plurality of air outlet openings, a gimbal joint mounting said gyro housing, said gyro spinning in response to air drawn through said inlet opening and outlet openings by a vacuum pump, valve means pivotally connected to said gyro housing and responsive to the position of said gyro housing to regulate the rate of flow of air from said outlet openings in response to movement of said aircraft from a selected horizon reference attitude, and limit means for controlling the amount of travel of said valve means, the improvement wherein said limit means includes a light-weight flexible strand having a breaking point greater than the force exerted by pivotal movement of the valve means, said strand being anchored at spaced parts thereof to said gyro housing and to said valve means at a midpoint of said strand whereby travel of said valve means is limited by the length of said strand between the points of connection thereof to said housing and to said valve means, said valve means pivoting substantially without restraint between said limits.