Method of making a fluid pressure actuator

Abstract

A fluid pressure actuator construction and method of making the same are provided, the method comprising the steps of forming a housing with an annular surface, securing an outer peripheral portion of a flexible diaphragm to the annular surface to define a fluid chamber with the housing whereby certain pressure differentials acting across the diaphragm cause movement thereof relative to the housing for actuation purposes or the like, and before the step of securing the diaphragm disposing a compression spring in the chamber to act between the housing and the diaphragm to tend to move the diaphragm in a direction away from the chamber, disposing a backup plate in the chamber so as to engage against the side of the diaphragm that faces the chamber, causing the spring to have one end thereof bearing against the backup plate, and forming the diaphragm to comprise a lamination having a polymeric layer defining the side thereof facing away from the chamber and a metallic layer defining the side thereof facing the chamber, and thereafter forming the diaphragm with an annular convolution adjacent the annular surface and inboard thereof by drawing the convolution in the diaphragm with a pressure differential created across the diaphragm after the diaphragm has been secured to the housing so as to have a convex side thereof facing the chamber.