Rotary diaphragmed pneumatic actuator

Claim 1

A ROTARY ACTUATOR COMPRISING A SHELL IN THE FORM OF A SEGMENT OF A SPHERE, A FLEXIBLE INELASTIC DIAPHRAGM HAVING A SPHERICAL PORTION CONFORMING TO AND IN CONTACT WITH THE INNER SURFACE OF SAID SHELL, SAID DIAPHRAGM HAVING AN INTEGRAL FLAT RADIALLY EXTENDING WALL, A FLAT BASE PLATE CLAMPED BETWEEN THE LOWER EDGE OF SAID WALL AND THE LOWER EDGE OF SAID SPHERICAL SEGMENT PORTION OF SAID DIAPHRAGM, SAID SEGMENTAL PORTION, SAID FLAT RADIAL WALL AND SAID BASE PLATE DEFINING A FLUID ENCLOSURE, MEANS FOR SUPPLYING PRESSURE FLUID TO THE INTERIOR OF SAID ENCLOSURE, A PISTON IN THE SHAPE OF A SEGMENT OF A SPHERE, SAID PISTON HAVING A FLAT SURFACE IN ENGAGEMENT WITH THE RADIALLY EXTENDING WALL OF SAID DIAPHRAGM, SAID DIAPHRAGM FORMING A CONVOLUTION BETWEEN THE SURFACE OF SAID PISTON AND SAID SHELL, AND SAID PISTON BEING ROTATABLE INTO SAID SHELL, AN OUTPUT SHAFT CONNECTED TO SAID PISTON AND ROTATABLE THEREWITH, AND A TORSION SPRING RESILIENTLY BIASING SAID PISTON FOR ROTATION INTO SAID SHELL.