Method for incremental sheet forming using resilient tooling

A method for incrementally forming at least two work areas of a work piece initially having a generally flat configuration and first and second opposed surfaces, positioned on an X-Y plane of an “X”, “Y”, “Z” three-dimensional orthogonal coordinate system, comprising:

• a. positioning a primary forming tool assembly adjacent to the first surface of the work piece in a first one of the at least two work areas, said primary forming tool assembly having a tool shaft comprising a tip capable of forming the work piece when forcibly engaged therewith, the tip having a hardness value that is greater than that of the work piece;
• b. positioning a backing forming tool assembly adjacent to the second surface of the work piece, said backing forming tool assembly capable of being moved in the Z direction, said backing forming tool assembly further having a compressible and resilient outer surface layer;
• c. advancing said backing forming tool assembly toward the work piece along the Z-axis to contact and support the second surface of the work piece opposite the position of the primary forming tool assembly;
• d. advancing said primary forming tool assembly along the Z-axis relative to the work piece to a predetermined Z coordinate so as to cause said tip of the tool shaft to engage the first surface of the work piece along a predetermined path of formation in a given direction and provide a predetermined amount of forming force thereon to form the work piece;
• e. maintaining the position of the backing forming tool assembly to provide a reactive force on the second surface of the work piece to the forming force;
• f. moving said primary forming tool assembly relative to the work piece on the X-Y plane along a predetermined set of X-Y coordinates while the tip of the tool shaft remains in contacting relation with the first surface of the work piece at substantially the same Z coordinate for exerting the forming force, thereby to follow the predetermined path of formation substantially parallel to the X-Y plane as the work piece is consistently formed in the Z direction;
• g. positioning said backing forming tool assembly along a predetermined path of formation opposite to the above given direction in tandem with the movement of said primary forming tool assembly to remain substantially opposite said tip of the primary forming tool assembly with the work piece therebetween, thereby maintaining localized force on the work piece;
• h. retracting said primary forming tool assembly and said backing forming tool assembly from the work piece;
• i. re-positioning the primary forming tool assembly adjacent to the first surface of the work piece in another one of the at least two work areas;
• j. repeating steps “b” through “h” successively within the other work area of the work piece;
• k. re-positioning the primary forming tool assembly adjacent to the first surface of the work piece in the first one of the at least two work areas;
• l. repeating steps “b” through “k” to form additional paths of formation in the at least two work areas by:
• i) utilizing an incrementally progressing value for the forming Z coordinate, and
• ii) alternating the direction of travel, counterclockwise or clockwise, along a path of formation at the incrementally-progressed forming Z coordinate.