Fluid pressure operated servo devices

Claim 1

A fluid pressure-operated servodevice comprising a casing with a rigid member disposed therein comprising a circular plate, movable axially of said casing, said plate having a flange facing in one direction adjacent its outer circumference forming a cylindrical surface, said plate extending radially inwardly adjacent the inner end of said flange to form an elongated flat surface, said plate terminating adjacent its central portion in a central cylindrical surface forming a right angle with radial extending flat surface, said central cylindrical surface extending in a direction opposite to said flange, a flexible diaphragm seated on said flange, radial surface and central cylindrical surface, a circumferential bead on the outer edge of said diaphragm, clamping flanges and a clamping ring encompassing said bead to secure it to the casing, an enlarged bead of concave-convex configuration on the inner edge of said diaphragm seated in said right angle, and a washer of concave-convex configuration secured on said central cylindrical surface and pressing against the outer surface of said enlarged bead to secure it in said right angle.