Field of the Invention

The present invention relates to an improved method for incrementally forming sheet materials such as sheet metal and plastics.

Cross-Reference to Related Applications

This application is related to U.S. Provisional Patent Application No. 62/844,177, entitled “Incremental Sheet Forming System with Resilient Tooling,” filed May 7, 2019, and U.S. Provisional Patent Application No. 63/006,802, entitled “Incremental Sheet Forming System with Resilient Tooling,” filed April 8, 2020. This application is also related to U.S. Patent Application No. 16/866,172, entitled “Incremental Sheet Forming System with Resilient Tooling,” filed on May 4, 2020, and issuing as U.S. Patent No. 11 ,440,073 on September 13, 2022, and to U.S. Patent Application No. 17/881 ,003, entitled “Incremental Sheet Forming System with Resilient Tooling,” filed on August 4, 2022. Furthermore, this application claims priority to US Provisional Application No. 63/404,338, filed September 7, 2022, entitled “Method for Incremental Sheet Forming Using Resilient Tooling.”

Background of the Invention and Description of the Related Prior Art

Numerous methods for forming sheet materials (typically metal) into complex shapes have been developed over the years. Sheet forming technologies exist across a wide range of industries and apply to a variety of metals and plastics sheet materials.

U.S. Patent No. 11 ,440,073 (Nardone) is directed to dual sided incremental sheet forming apparatus and method that includes a primary forming tool assembly and a secondary (backing) forming tool assembly with a sheet material work piece having two surfaces positioned therebetween. The secondary forming tool assembly includes a compressible and resilient layer of material that is located adjacent to the work piece. The primary forming tool assembly follows a series of predetermined paths along the first surface of the work piece while the backing forming tool assembly simultaneously follows the same paths along the second surface of the work piece (See FIGS. 6A-D, 7, and 8A-B of the ‘073 Patent).

Due to its plasticity and pliability, the work piece is permanently formed by the force applied on its first surface by the primary forming tool assembly. In turn, the work piece compresses the resilient layer of the backing tool assembly to create localized forces on the work piece. By sequentially repeating movement along the predetermined tool paths while incrementally advancing the primary forming tool assembly toward the work piece (i.e., along Z coordinates), the work piece can be formed into a desired configuration (FIG. 8 of the ‘073 Patent).

The method used with the incremental sheet metal forming system of the ‘073 Patent provided flexibility over prior art systems by removing the need for producing and using expensive dies to form complex sheet metal parts. Its method also advantageously localized the forming forces on the work piece so as to control precisely and locally the stress that occurs during the formation of the sheet material thus avoiding the potential for wrinkling and tearing (e.g., penetration) of the resulting work piece.

Summary

By way of illustration only, the present method invention is applicable to processes for forming parts and components from sheet materials for all major industries such as automotive, aerospace, industrial, architectural, engineering, construction, and consumer products.

In accordance with the present invention, an improved method is provided for incrementally forming sheet materials such as sheet metal and sheet plastics (work piece). The work piece has at least one work area and first and second opposed and substantially parallel surfaces positioned on an X-Y plane of an “X”, “Y”, “Z” three- dimensional orthogonal coordinate system.

With the present invention, it surprisingly has been found that the method of the ‘073 Patent can be improved by alternating or reversing the direction of travel along adjacent paths or groups of paths (e.g., alternating counterclockwise and clockwise directions). As a result, dimensional accuracy, tighter tolerances, consistency, and reproducibility of the final sheet metal configuration can be heightened. By alternating or reversing the directional passes of the predetermined pathways, directional biases and resulting localized stresses are reduced, thus avoiding the potential for warping and/or twisting of the resulting work piece.

The inventive method comprises the steps of providing an apparatus having a primary forming tool assembly positioned adjacent to and facing the first surface of a work piece, and a secondary or backing forming tool assembly having a compressible and resilient surface portion that is positioned adjacent to and facing a second surface of the work piece. The primary forming tool assembly and the backing forming tool assembly are configured and arranged for independently moving in a predetermined sequence and pattern relative to each other. The primary forming tool assembly is positioned relative to the work piece to move to a predetermined X, Y, Z coordinate so as to be adjacent to the first surface of the work piece within the work area. The backing forming tool assembly moves relative to the work piece to a predetermined Z coordinate within a work area so as to be in contact with the second surface of the work piece and opposite the position of the primary forming tool assembly.

In accordance with this inventive method, the primary forming tool assembly advance toward the work piece along the Z axis to a predetermined Z coordinate so as to contact and exert a forming force on the first surface of the work piece at an area of contact within the work area, thereby forming the work piece into a predetermined configuration, and compressing the backing forming tool assembly to support the second surface of the work piece resulting in a localized force within the area of contact while the work piece is being formed. The primary forming tool assembly moves relative to the work piece parallel to the X-Y plane along a predetermined set of coordinates to one of the predetermined tool paths while retaining substantially the same Z coordinate so as to follow a predetermined path of formation as the work piece is consistently formed in the Z direction within the work area. The primary forming tool assembly is retracted away from the work piece in the Z direction. These steps are sequentially repeated with movement along adjacent predetermined paths or adjacent groups of paths provided in alternating directions (i.e., alternating clockwise or counterclockwise passes) by utilizing incrementally progressing values for the Z coordinates until the work piece is formed.

In accordance with aspects of the present disclosure, a method is disclosed for incrementally forming a work piece having at least one work area and having first and second opposed and substantially parallel surfaces positioned on an X-Y plane of an “X”, “Y”, “Z” three-dimensional orthogonal coordinate system. An apparatus is provided having a primary forming tool assembly positioned adjacent to and facing the first surface of the work piece, and a backing forming tool assembly having a compressible and resilient surface layer that is positioned adjacent to and facing the second surface of the work piece. The primary forming tool assembly and the backing forming tool assembly are configured and arranged for independently moving in a predetermined sequence and pattern relative to each other, and the primary forming tool assembly further has a tool shaft including a tip that is arranged to face toward the first surface of the work piece and positioned opposite the backing forming tool assembly. The primary forming tool assembly is positioned relative to the work piece to move to a predetermined X, Y, Z coordinate to be adjacent to the first surface of the work piece within the work area, and the backing forming tool assembly is positioned relative to the work piece to move simultaneously to a predetermined Z coordinate within the work area to be in contact with the second surface of the work piece and opposite the position of the primary forming tool assembly. The primary forming tool assembly is then advanced toward the work piece along the Z-axis to another predetermined Z coordinate to cause the tip of the tool shaft to contact and exert a forming force on the first surface of the work piece at a localized area of contact within the work area. As a result, the work piece is thereby formed into a predetermined configuration and the resilient surface layer of the backing forming tool assembly is compressed to support the second surface of the work piece. This results in a localized force being applied within the area of contact while the work piece is being formed. The primary forming tool assembly is then moved relative to the work piece on an X-Y plane along a predetermined set of 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 to follow a predetermined path of formation substantially parallel to the X-Y plane as the work piece is consistently formed in the Z direction within the work area. The primary forming tool assembly is then retracted away from the work piece. These steps to form the path of formation are repeated to form additional paths of formation by sequentially utilizing incrementally progressing values for the predetermined Z coordinates, and alternating the direction of travel of the primary forming tool assembly, counterclockwise or clockwise, along successive paths of formation until the work piece is fully formed in the work area.

In accordance with additional aspects of the present disclosure, the method may be performed such that the direction of travel to form the additional paths is alternated for successive groupings of paths of formation.

In accordance with additional aspects of the present disclosure, the method may be performed such that the direction of travel to form the additional paths is alternated for each successive one of the additional paths.

In accordance with additional aspects of the present disclosure, the method may include the additional steps of providing a controller assembly that is capable of simultaneously coordinating the respective positioning of the primary forming tool assembly and the backing forming tool assembly in relation to each other. At least one sensor is provided to measure the amount of formation of the work piece at specified positions along the path of formation of the work piece. Measurements from the sensor are used to compare a predetermined amount of formation at the same specified positions along the path of formation, and the resulting compared measurements are relayed to the controller assembly. The controller assembly then adjusts the position of at least one of the primary forming tool assembly and the backing forming tool assembly relative to preprogrammed amounts of formation along the paths of formation to form the work piece into the predetermined configuration.

The provided sensor may be selected to be of a contact type such that the sensor measures the amount of formation of the work piece by physically contacting the work piece. Alternatively, the sensor may be selected to be of a non-contact type such that the sensor measures the amount of formation of the work piece without physically contacting the work piece.

In accordance with further aspects of the present disclosure, a method is disclosed 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. A primary forming tool assembly is positioned adjacent to the first surface of the work piece in a first one of the at least two work areas. The primary forming tool assembly has a tool shaft including a tip capable of forming the work piece when forcibly engaged therewith. The tip has a hardness value that is greater than that of the work piece. A backing forming tool assembly is positioned adjacent to the second surface of the work piece. The backing forming tool assembly is capable of being moved in the Z direction, and has a compressible and resilient outer surface layer. The backing forming tool assembly is advanced 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. The primary forming tool assembly is then advanced along the Z-axis relative to the work piece to a predetermined Z coordinate 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. The position of the backing forming tool assembly is maintained to provide a reactive force on the second surface of the work piece to the forming force. Then the primary forming tool assembly is moved 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 following the predetermined path of formation substantially parallel to the X-Y plane as the work piece is consistently formed in the Z direction. The backing forming tool assembly is positioned along a predetermined path of formation opposite to the above-described given direction in tandem with the movement of the primary forming tool assembly to remain substantially opposite the tip of the primary forming tool assembly with the work piece therebetween, thereby maintaining localized force on the work piece. The primary forming tool assembly and the backing forming tool assembly are then retracted from the work piece, and the primary forming tool assembly is then re-positioned adjacent to the first surface of the work piece in another one of the at least two work areas. The above steps for forming the predetermined path of formation are repeated successively within the other work area of the work piece, and the primary forming tool assembly is re-positioned adjacent to the first surface of the work piece in the first one of the at least two work areas. These steps are then repeated to form additional paths of formation in the at least two work areas by utilizing an incrementally progressing value for the forming Z coordinate, and alternating the direction of travel, counterclockwise or clockwise, along a path of formation at the incrementally-progressed forming Z coordinate.

In accordance with additional aspects of the present disclosure, this method may be performed such that the direction of travel to form the additional paths is alternated for successive groupings of paths of formation.

In accordance with additional aspects of the present disclosure, the method may be performed such that the direction of travel to form the additional paths is alternated for each successive one of the additional paths.

In accordance with additional aspects of the present disclosure, this method may further include then 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, and repeating the above- described steps to form additional paths of formation in each of the at least two work areas by utilizing additional incrementally progressing values for the Z coordinates, and alternating the direction of travel, counterclockwise or clockwise, along the additional paths of formation at the incrementally-progressed forming Z coordinates.

In accordance with additional aspects of the present disclosure, the method continue to repeat the above-described steps until the work piece is fully formed in the at least two work areas.

Brief Description of the Drawings

FIGS. 1 A - D depict exemplary front cross-sectional views of a work piece undergoing a sequence of incremental forming method steps in accordance with the present invention.

FIGS. 2A and B depict exemplary top views illustrating methods for forming a work piece in accordance with aspects of the present invention.

FIGS. 3A and B depict methods for forming multiple formation areas in a single work piece undergoing a sequence of incremental forming steps in accordance with the present invention. In particular:

FIGS. 3A and B depict exemplary top views illustrating methods for forming a work piece in accordance with aspects of the present invention; and

FIG. 3C depicts an exemplary front cross-sectional view of a work piece undergoing a sequence of incremental multiple forming steps in accordance with the present invention, and in particular as depicted in FIGS. 3A - B.

FIG. 4 depicts a partial cross-sectional view of the above embodiments of the present invention with a diagram of a synchronized control system.

Detailed Description The present invention is directed to an enhanced method for incremental sheet material forming by using tooling that follow alternating directional movement along predetermined tool paths to form a variety of shapes with a minimal amount of force.

When using a method from the ‘073 Patent, it is thought that when tool paths are created as the forming tools assemblies advance along a work piece only in one direction (e.g., either all counterclockwise or all clockwise), each passage creates a small directionally biased force, which accumulates with each sequential pass. By alternating the directions traveled along adjacent tool paths or groupings of tool paths, Applicant surprisingly has found that these individual directionally created biased forces can be rebalanced and diffused, thus reducing the possibility of sheet metal warping and/or twisting of the shape formed in the work piece. As a result, localized stresses in the work piece are reduced, and dimensional accuracy, tighter tolerances, consistency, and reproducibility of the final sheet metal configuration is heightened. In particular, this inventive approach has been found to enhance the formation accuracy of highly-detailed asymmetric shapes in sheet materials.

For efficiency and ease of comparison, the component numbering system of the ‘073 Patent where applicable has been retained in the present patent filing.

FIGS. 1 A - D, 2 and 3A and B respectively show exemplary cross-sectional views of work piece 80 undergoing a sequence of incremental forming steps along illustrative work paths in accordance with the method of the present invention.

FIGS. 1A - D depict exemplary front cross-sectional views of work piece 80 undergoing a sequence of incremental forming steps from starting as a flat sheet (See e.g., FIG. 1A) through its forming into a final configuration 81 (See e.g., FIG. 61 ) in accordance with the method of the present invention.

More specifically, FIGS. 1A - D show primary forming tool assembly 10, work piece 80 and secondary or backing forming tool assembly 90. Backing forming tool assembly 90 comprises resilient surface material layer 92 (or the outer surface portion of backing tool assembly 90), secured to rigid backing 91.

During the forming process, work piece 80 is pressed between primary forming tool assembly 10 and backing forming tool assembly 90. Primary forming tool assembly 10 exerts controlled force onto one surface of work piece 80. As a result, work piece 80 deforms and places force on resilient layer 92. In turn, resilient layer 92 compresses and places a counter force from the opposite surface of work piece 80 so as to support the work piece at the localized area of contact surrounding primary forming tool assembly 10. As a result, work piece 80 is plastically and permanently formed.

Resilient layer 92 remains compressed while primary forming tool assembly 10 remains in contact with work piece 80 and resilient layer 92 remains in contact with work piece 80. Resilient layer 92, however, returns to its pre-compressed configuration once primary forming tool assembly 10 moves away from work piece 80 along the Z-axis or when the backing forming tool assembly 90 moves along the Z-axis away from work piece 80 to another preprogrammed and predetermined position.

During the forming process, primary forming tool assembly 10 stays firm due to its hardness and rigidity. Due to its plasticity and pliability, work piece 80 is readily and permanently formed by the force applied on it by primary forming tool assembly 10. In turn, resilient layer 92 also temporarily deforms on account of the force exerted on it by work piece 80.

The forces exerted by primary forming tool assembly 10 are substantially concentrated at the area of contact between the tool 10 and work piece 80. At this contact area or “zone of tangency”, the force exerted by work piece 80 on resilient surface material layer 92 advantageously remains concentrated and localized near the point of contact by primary forming tool assembly 10, thus avoiding warping and tearing of the resulting work piece. Resilient surface material layer 92 substantially returns to its original or non-com pressed shape as the force from the primary forming tool assembly 10 onto work piece 80 is removed and/or backing forming tool assembly 90 moves along the Z-axis away from work piece 80. In operation, resilient layer 92 may be compressed with respect to the Z- axis, in a range of about 0.001 to about 0.2 inches or larger, preferably about 0.005 to about 0.1 inches, depending upon the material selected, its thickness and the dimensions of work piece 80.

In FIGS. 1 A - D, primary forming tool assembly 10 and backing forming tool assembly 90 preferably are controlled by an electro-mechanical positioning system having a predetermined or preprogrammed motion that results in localized controlled force on work piece 80. In other words, CNC programming techniques are utilized that relate to establishing controlled positioning and direction of movement of the tool assemblies along the predetermined paths in order to achieve this result and desired formation of work piece 80.

All movement of the forming tool assemblies are preferably actuated by such electromechanical means. Servo motors are the preferable electro-mechanical drive means. Stepper motors are also usable as an electro-mechanical drive means. Additionally, precision hydraulics may be utilized for one or more of the actuated axes of the mechanical system as an alternate. See also FIG. 4 and its accompanying description.

Alternatively, the primary forming tool assembly 10 or backing forming tool assembly 90 or both forming tools may be controlled as a function of pressure. In this alternative method, either or both primary forming tool assembly 10 and backing forming tool assembly 90 is controlled in the Z direction by an electro-mechanical positioning system that exerts a targeted force on work piece 80. This allows the pressure-controlled tool (or tools) to vary their position in the Z-axis in order to keep a predetermined pressure on their corresponding surfaces of work piece 80. In other words, other known CNC programming techniques are utilized that relate to specified pressure values. See, for example, U.S. Patent No. 7,536,892, issued May 26, 2009 and entitled “Method and apparatus for forming sheet metal.” FIG 2A depicts an inventive method by which tool paths are created in adjacent alternating directions. In FIG. 2A, primary forming tool assembly 10 illustratively moves along outer tool path 83 in a counterclockwise direction on a plane offset from the plane defined by original work piece 80. Primary forming tool assembly 10 advances along the Z-axis, applying controlled force to work piece 80 as shown in FIGS. 1A - D. As primary forming tool assembly 10 then moves along outer tool path 83 in the counterclockwise direction, the primary forming tool continues to apply force to work piece 80. While work piece 80 is being formed, resilient layer 92 of secondary forming tool assembly (e.g., backing forming tool assembly 90) as depicted in FIG. 3C also deforms and applies a controlled counter force on the work piece from the opposite surface. As a result, work piece 80 receives a localized force in the area in which it is contacted by forming tool assembly 10 and is plastically formed along a selected tool path.

More specifically, FIG. 2A depicts work piece 80 which has one work area with multiple tool paths where formation of the work piece increases toward the center of the work piece. As a result, once the first tool path 83A (counterclockwise direction) run is completed, backing forming tool assembly 90 moves away (along the Z-axis) by a predetermined distance from the lower surface of work piece 80, and primary forming tool assembly 10 moves towards work piece 80 and along second tool path 84A on the Z-axis to provide sufficient reactive and localized force to the work piece to counter the forming force on the work piece from the primary forming tool assembly 10. Along the direction of second tool path 84A, primary forming tool assembly 10 and backing forming tool assembly 90 continuously positioned in tandem - but this time in the clockwise direction - with the movements of the tip of primary forming tool assembly 10 to remain substantially opposite the backing forming tool assembly 90 with work piece 80 therein between.

In FIG. 2A, once the clockwise directional run of second tool path 84A is completed, primary forming tool assembly 10 and backing forming tool assembly 90 move in the manner described above so as to create third tool path 83B - but this time move along tool path 83B in the counterclockwise direction. Once the counterclockwise directional run of third tool path 83B is completed, primary forming tool assembly 10 and backing forming tool assembly 90 move in the manner described above, so as to create fourth tool path 84B - but this time, move along tool path 84B in the clockwise direction.

In other words, primary forming tool assembly 10 forms the surface of work piece 80 by forcing the work piece into resilient layer 92 (See FIGS. 1A - D and 3C) in the counterclockwise direction along tool path 83A. When finished, the forming process begins again on next adjacent tool path 84A (See FIG. 2A) in the clockwise direction. The process is repeated, and based on each successive tool path, alternating travel directions (counterclockwise to clockwise), until the forming process is completed and work piece 80 is formed in its final configuration 81.

As a result, two forming tool assemblies, 10 and 90, have created the paths while formed in alternating directions (e.g., counterclockwise, then clockwise, then counterclockwise, then clockwise) along the tool paths. Consequently, the formation forces remain localized and the biased directional forces and resulting stresses that were created by travel along the paths are rebalanced relative to adjacent paths on the work piece. With alternating passage directions along adjacent paths or groups of paths, these small, individual, directionally created biased forces can be rebalanced and diffused, thus, reducing the possibility of sheet metal warping. By rebalancing the biased directional forces by alternating the direction of travel along adjacent or groups of tool paths, the resulting dimensional accuracy, tighter tolerances, consistency, and reproducibility of the final sheet material configuration can be heightened.

FIG 2B depicts an inventive method by which tool paths are created by grouping the tool paths and creating the grouping by traveling in alternating directions between groups. As illustrated in FIG 2B, the two forming tool assemblies, 10 and 90, have created tool paths that are organized into alternating groups of two tool paths for traveling along the pathway (i.e. , by traveling counterclockwise for two adjacent tool paths (e.g., 83A and 84A), then by traveling clockwise for the next two adjacent tool paths (83B and 84B). Due to the use of groupings of tool paths being created with movement in alternating directions, the formation forces remain localized and the biased directional forces and stresses that are created by travel along the paths in each direction are rebalanced or cancelled relative to adjacent paths on the work piece.

By either alternating passage directions along adjacent paths (Fig. 2A) or altering groupings of tool paths (FIG. 2B), the directionally created biased forces can be rebalanced and generally diffused or cancelled out , thus, reducing the possibility of sheet metal warping. As a result of rebalancing the directionally biased forces by alternating the direction of travel along adjacent (FIG. 2A) or groupings of tool paths (FIG. 2B), the resulting dimensional accuracy, tighter tolerances, consistency, and reproducibility of the final sheet metal configuration can be enhanced.

As illustrated in FIGS. 3A and B, other inventive tool path methods may be used to create configurations with more than one formed or work area 100 per sheet of material. More specifically, FIGS. 3A and B show work piece 80 with two work areas 100 that are separated from each other. These figures depict a method for forming multiple formations in the two separate work areas on work piece 80 that is undergoing a sequence of incremental forming steps in accordance with the method of the present invention. The present method, thus, is applicable to work pieces have one or multiple work areas.

FIG. 3A depicts tool paths 101 through 108. Tool paths 101 , 103, 105, and 107, are applicable to a first formed area 100, and tool paths 102, 104, 106 and 108 are applicable to a second formed area 100. Travel along tool paths 101 and 102 is shown as counterclockwise. Travel along tool paths 103 and 104 is shown as clockwise. Travel along tool paths 105 and 106 is shown as counterclockwise. Travel along tool paths 107 and 108 is shown as clockwise.

FIG. 3B also depicts tool paths 101 through 108. Tool paths 101 , 103, 105, and 107, are applicable to a first formed area 100, and tool paths 102, 104, 106 and 108 are applicable to a second formed area 100. However, travel along tool paths 101 and 102 and respectively travel along adjacent tool paths 103 and 104 are shown as counterclockwise. Travel along tool paths 105 and 106 and respectively travel along adjacent tool paths 107 and 108 are shown as clockwise. Many other alternating tool path travel patterns for these and other configurations are possible and contemplated within the scope of the present disclosure.

FIG 3C depicts an exemplary final front cross-sectional view with respect to FIGs. 3A and 3B of a work piece having undergone a sequence of incremental multiple forming steps in accordance with the method of the present invention and formed into its final configuration 81. More specifically, FIG. 3C shows primary forming tool assembly 10 and backing forming tool assembly 90. This backing or secondary forming tool assembly comprises resilient layer 92 and rigid backing 91.

In the embodiment of FIGS. 3A and B, primary forming tool assembly 10 follow tool paths 101 - 108 in numerical sequence (/.e., in the order of 101, 102, 103, 104, 105, 106, 107, and finally 108.) In this example, generally corresponding tool paths 101 and 102, 103 and 104, 105 and 106, 107 and 108 respectively are positioned along an X-Y plane at substantially the same position on the Z-axis. Primary forming tool assembly 10 moves to the selected Z-axis position of tool path 101 somewhere along the length of tool path 101. Resilient backing forming tool assembly 90 moves in the Z-axis direction to substantially the same Z-axis position as that of tool path 101 (or a preselected dimensional offset in the positive or negative position in the Z-axis direction) which is substantially the same as that of tool path 101.

In FIG. 3A, primary forming tool assembly 10 then proceeds to exert force along tool path 101 and travels in a counterclockwise direction as work piece 80 forms and resilient backing forming tool assembly 90 supports the work piece. When counterclockwise movement along tool path 101 is completed, primary forming tool assembly 10 then retracts in the Z-axis direction, away from work piece 80, past the original X-Y reference plane 82 of work piece 80 to X-Y clearance plane 109 (see FIG. 3C). Clearance plane 109 is located at a sufficient distance away from reference plane 82 to allow primary forming tool assembly 10 not to be in contact with the surface of work piece 80. Then, primary forming tool assembly 10 proceeds to a newly selected X-Y location above tool path 102 while still positioned along clearance plane 109. Primary forming tool assembly 10 then moves toward work piece 80 to substantially the same Z-axis position on tool path 102 as previously selected for tool path 101.

In FIG. 3A, primary forming tool assembly 10 proceeds to exert force along tool path 102 and travels in a counterclockwise direction as work piece 80 forms and resilient backing forming tool assembly 90 supports the work piece. As a result, the amount of formation of work piece 80 along tool path 102 is substantially the same amount of formation as along tool path 101. During the movement in a counterclockwise direction of primary tool assembly 10 along tool paths 101 and tool path 102, in this example, backing forming tool assembly 90 has not yet changed its position on the Z-axis.

Primary forming tool assembly 10 then retracts again in the Z-axis direction, away from work piece 80, past the original reference plane 82 and back to clearance plane 109. Primary forming tool assembly 10 then proceeds to an X-Y location above tool path 103. Resilient backing forming tool assembly 90 also moves away from work piece 80 to a preselected Z-axis position (or a dimensional offset in the positive or negative dimension in the Z-axis direction). Primary forming tool assembly 10 then moves to the selected Z- axis level of tool path 103 and proceeds along tool path 103 traveling in a clockwise direction. When the formation is completed along tool path 103, primary forming tool assembly 10 proceeds to a newly selected X-Y location above tool path 104 while still positioned along clearance plane 109. Primary forming tool assembly 10 then moves toward work piece 80 to substantially the same Z-axis position on tool path 104 as previously selected for tool path 101.

In FIG. 3A, primary forming tool assembly 10 then proceeds to travel in a clockwise direction to exert force along tool path 104 as work piece 80 forms and resilient backing forming tool assembly 90 supports the work piece. As a result, the amount of formation of work piece 80 along tool path 104 is substantially the same amount of formation as along tool path 103. During the movement of primary tool assembly 10 in a clockwise direction along tool paths 103 and tool path 104, in this example, resilient backing forming tool assembly 90 has not substantially changed its position on the Z-axis.

The method of FIG. 3A, then repeats and continues for tool paths 105 and 106 (traveling in a counterclockwise direction), 107 and 108 (traveling in a clockwise direction), until work piece 80 is formed into its final shape with multiple formations. In other words, those tool paths which are to be formed at substantially the same Z-axis level are processed all in sequence but in alternating or reversing directions (i.e., counterclockwise, and then clockwise) so as to form all tool paths having substantially the same Z-axis level of the final configuration.

In accordance with the present inventive method, multiple formations on a single sheet of material do not need to have the same final shape or the same final amount of formation. Where different configurations of multiple formations are required on a single sheet of material, the above incremental process would start along the tool paths where the least amount of formation is contemplated for the multiple formations. Then, the process moves along the Z-axis onto the tool paths where the next amount of formation is contemplated, and then continues until all tool path configurations are completed and the final form is achieved. Moreover, as shown in FIGS. 3A and B, a single sheet of material does not need to have the same final shape or the same final amount of formation in each of the various work areas.

Additionally, as seen in FIG 3B, the corresponding tool paths that have the same Z-axis positioning (e.g., 101 and 102; 103 and 104; 105 and 106; and 107 and 108) are not required to travel in the same direction in each work area. As long as the travel direction for adjacent tool paths are alternating, for example, if desired, the direction along the work piece of tool path 101 of the first work area in FIG. 3B and that of corresponding tool path 102 of the second work area need not be the same. In other words, the inventive method contemplates that the corresponding tool paths both moving in the counterclockwise direction as shown in FIG. 3A in various work areas or that one of the tool paths moving in the counterclockwise direction and the other moves in the clockwise direction in each work area as shown in FIG. 3B.

Moreover, in addition to organizing adjacent tool paths in groupings of two as seen in FIG. 3B, the inventive method also contemplates establishing other grouping of altering paths such that the groups may include groupings of 3 adjacent tool path, or 4 adjacent tool paths, or 5 adjacent tool paths or combinations thereof (e.g., groupings of adjacent 2 and 3 tool paths; 2 and 4 tool paths ; 2 and 5 tool paths ; 3 and 4 tool paths; 3 and 5 tool paths; and 4 and 5 tool paths).

FIG. 4 depicts a partial cross-sectional view of embodiments of the present invention in combination with a synchronized control system. FIG. 4 shows synchronized controller assembly 85, non-contact measurement sensor 86 and contact measuring sensor 87. FIG. 4 also shows primary forming tool assembly 10, and secondary forming tool assembly e.g., backing forming tool assembly 90). The secondary forming tool assembly comprises resilient layer 92 and rigid backing 91.

In FIG. 4, one or more controllers or control modules may be provided for a synchronized controlling operation applicable with the components described in the above embodiments. By way of illustration, synchronized controller assembly 85 monitors and controls the precise positioning of sheet feeding roller assembly 40 (See e.g., FIGS. 1A - C of the ‘073 Patent) or sheet feeding belt assembly 43 (See e g., FIGS. 2A - C of the ‘073 Patent) or sheet fixture assembly 50 (See e.g., FIGS. 3A - C of the '073 Patent ) or worktable assembly 71 (See e.g., FIG. 5 of the ‘073 Patent) (not all components are shown in FIG. 4), primary forming tool assembly 10, and secondary forming tool assembly 90 (similar to backing roller tool assembly 20 (See e.g., FIGS. 1 A - B, 2A - B and 3A - B of the ‘073 Patent) or backing flat tool assembly 30 (See e.g., FIGS. 4A - B and 5 of the ‘073 Patent)). Synchronized controller assembly 85 may interact with the various subsystems directly. Alternatively, synchronized controller assembly 85 may interact indirectly by obtaining position information for each subsystem to determine and provide a coordinated control.

In FIG. 4, synchronized controller assembly 85 may operate based on NC (numeric control) data in accordance with the art. Synchronized controller assembly 85 may be adapted to receive CAD data from which to derive numerical control data to form work piece 80 to design specifications. Controller assembly 85 may monitor the position and formation process of work piece 80 via contact sensor 87 that physically contacts work piece 80, or without physical contact via non-contact sensor 86 (/.e., laser or optical measurement system). The control system including synchronized controller assembly 85, contact sensor 87, and non-contact sensor 86 may monitor the position of work piece 80 at the start of the inventive forming process and preferably repeatedly throughout the forming process.

In accordance with FIG. 4, a non-contact sensor 86 or contact sensor 87 is provided as described above to measure the amount of formation of the work piece 80 at specified positions along the path of formation of the work piece. The resulting measurements from sensors 86 or 87 are compared to a predetermined amount of formation at the same specified positions along the path of formation. The resulting compared measurements are relayed to the controller assembly 85. Controller assembly 85 then adjusts the position of at least one of primary forming tool assembly 10 and backing forming tool assembly 90 relative to the preprogrammed amounts of required formation along the path so as to form the work piece into the predetermined shape. See also U.S. Patent No. 7,536,892.

While the control system depicted in FIG. 4 is shown in connection with a preferred embodiment of the inventive method, this control system can be utilized with any of the embodiments and methods of the invention which are described herein or in the ‘073 Patent. Detailed embodiments of the present method invention have been disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the method invention that may be embodied in various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.

Moreover, in the figures, reference is made to the X, Y and Z axes of a 3-dimensional orthogonal coordinate system with regard to the movement of the various components according to the present method, (such as primary forming tool assembly 10; and backing roller tool assembly 20 or backing flat tool assembly 30 or backing forming tool assembly 90), all relative to each other. It is to be understood that the movement of the various components is intended to be depicted in relation to the movement of each of the other components and a reference plane, as applicable (/.e., defined by the initial configuration of the work piece prior incrementally forming).

Additionally, reference is made to certain surfaces being first or second surfaces, upper or lower, or vertical or horizontal and the like. Such descriptions of direction are intended to be consider in relation to the appropriate X, Y and Z axes as shown in the applicable figures.

Furthermore, the reference plane is depicted as X-Y plane 82 in FIGS. 1A - D, and 3C. For simplicity, the reference plane is not shown in the other drawings but is intended to be the initial generally flat configuration of work piece 80 along an X-Y plane prior to incremental formation.