Patent ID: 8840828

Claim:
A method of conforming a blank onto forming surface sections of a forming tool by drawing a first vacuum against an elastic forming medium for transmitting forming forces from the elastic forming medium to the blank, the method comprising: applying the blank to the forming tool; enclosing the blank within the elastic forming medium, wherein the elastic forming medium comprises at least one void; evacuating the elastic forming medium with the first vacuum for allowing the elastic forming medium to stretch and conform the blank to the forming surface sections; applying a second vacuum to the at least one void in the elastic forming medium to achieve at least one stiffened section of the elastic forming medium corresponding with a location of the at least one void in the elastic forming medium and corresponding with a forming surface section of the forming tool at which the blank requires application of a forming force on the blank larger than a forming force on the blank of surrounding sections of the forming tool when the elastic forming medium lies against the blank and the blank lies against the forming tool after completion of the evacuation; and removing the formed blank, constituting an article, from the forming tool after completion of the evacuation.