Patent Publication Number: US-2019184442-A1

Title: Machine and method for forming inter-sheet registering contours in metal blanks for separation

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     This disclosure relates to a machine for forming registering contour features by displacing material in, and a method for separating workpieces so that they do not adhere to each other in a manufacturing process. 
     Relatedly, the present disclosure involves a prescribed topography for those registering contour features in a predictable location adjacent a peripheral or other edge to facilitate separation of the workpieces after they are stacked. 
     (2) Description of Related Art 
     In the metal fabricating industry, workpieces sometimes known as “blanks” are often provided in sheet, shaped or coil-form. Often, a type of lubricant, preservative or oil is added to the workpieces or coils (collectively, “workpieces”) so that they do not corrode. Such fluids may cause stacked workpieces to stick together when arranged in a stacked formation like a deck of cards. 
     One way to separate the workpieces so that they do not adhere to each other or stack unevenly from side-to-side is to provide an air gap between them by introducing a spacer. In the case of ferrous materials, a magnet may be used to separate the workpieces. 
     Generally, after a metal workpiece has been cut from a coil or a larger blank to make a workpiece, the resulting materials are stacked on top of each other for storage, transportation, or further processing. When the metal workpieces are stacked, there is little or no separation between them. Often the only matter that lies between adjacent sheets is a film of lubricant or preservative. As a result, it may be hard to separate the workpieces because they may tend to stick together, particularly under the weight of workpieces lying in a stacked column there above. 
     Adhesion between workpieces complicates or prohibits the task of removing a single workpiece (which may or may not be planar) by non-destructively inserting a separating tool to raise an uppermost workpiece from the top of a column of stacked workpieces or an intermediate workpiece. 
     Among the art considered before filing this application are: U.S. Pat. Nos. 7,034,683; 8,322,955; 8,766,797; 9,346,094; 9,623,470; 2010/0017347; 2011/0227725; 2016/0279687 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, it would be useful to have a way to stack workpieces so that the uppermost workpieces can be readily removed from a column of such workpieces without adding external, possibly contaminating substances, such as talcum powder or its equivalents. To do this, it would be helpful to have a machine that forms cooperating registering contour features in adjacent workpieces. When stacked with such contour features, most of the surface areas of adjacent workpieces are at least partially separated by an interstitial space that is punctuated only by those limited areas of contact between the cooperating contour features, such as one or more annular rims with rims close to the edges of adjacent workpieces. 
     An exemplary embodiment of cooperating registering contour features at a predetermined location in a workpiece for inter-workpiece separation has a concave basin-shaped section within an outside annular rim. Inside the outer rim, the basin-shaped section extends downwardly within the outer rim. Thus, the present disclosure relates to a machine and method for forming registering contour features for inter-workpiece separation in workpieces. More specifically, the registering contour features are optionally but not necessarily placed adjacent to a peripheral or other edge of a workpiece. Alternatively, the registering contour features may be placed elsewhere in a workpiece so that the registering contour features in adjacent workpieces cooperate or register to enforce a separation between most of the surface areas between adjacent workpieces. 
     In practice, the disclosed process and its variants enable an operator to form a registering contour feature predictably and precisely at the same location in each workpiece before the workpieces are stacked and thus create an air gap or space between inter-contour feature regions within each workpiece of adjacent workpieces. Optionally, the disclosed process and its variants provide a way to create such contour features before the workpiece is cut from a coil or larger workpiece. In skilled art of making formed parts from a coil, present practices favor forming to be done before or during cutting. Thus, in most cases, an edge area that includes registering contour features is typically cut from the workpiece after the registering contour features are formed and before a subsequent manufacturing step. 
     It will be appreciated that the disclosed registering contour features need not have a circular footprint. Optional embodiments also involve displacing material and may be elliptical, oval, race-track in shape or have curved or angular (e.g., hexagonal or polygonal) perimeters. 
     One characteristic that the various footprints share is that they are formed by upward or downward flow of material (or both), preferably in a forming or coining step. 
     In a given workpiece, the intermediate region lies between the registering contour features of that sheet. When stacked, a gap is created between such regions of adjacent workpieces. The gap separates them so that the uppermost workpiece can be removed, slid, lifted or otherwise displaced if desired non-destructively and not be caused to adhere by a lubricant or other material between the workpieces. 
     In some applications, a workpiece may have one section that has a thickness that differs from the thickness of a neighboring section. For such cases, registering contour features may be deployed to promote stacking efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a quartering perspective view of an apparatus including a press with a lower die and an upper die in accordance with one embodiment and practice variant. 
         FIG. 2  is a sectional view of the apparatus in an open position with an annular rim-shaped outer contour feature forming tool and a button-shaped inner contour feature forming tool. 
         FIG. 2A  is an enlarged portion (A) of  FIG. 2  that illustrates the annular rim-shaped outer forming tool and the button-shaped inner forming tool in more detail. 
         FIG. 3  illustrates the apparatus in a position where an outer annular rim and crater are formed. 
         FIG. 3A  is a view of a workpiece; 
         FIG. 4  illustrates the apparatus in a position where an inner annular rim is formed, at which point in the movement or travel of the press, all forming of the localizing contour feature is complete. 
         FIG. 4A  is a view of the resulting workpiece. 
         FIG. 5  illustrates the apparatus in a closed position. 
         FIG. 5A  is a view of the resulting workpiece. 
         FIG. 6  is a representative top view of a registering contour feature made with the disclosed apparatus. 
         FIG. 7  shows sectional views of stacked workpieces and registering contour features. 
         FIG. 8  shows sectional views of intermediate regions between registering contour features of adjacent workpieces in partial registration with each other to enforce a spacing between the intermediate regions of adjacent workpieces. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the 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 teaching one skilled in the art to variously employ the present invention. 
       FIGS. 1-5  show an overall apparatus and exemplary parts of an embodiment of the forming apparatus. In summary, those parts include a press with lower and upper die sets; 
     
       
         
           
               
            
               
                   
               
               
                 Parts List 
               
            
           
           
               
               
            
               
                 ITEM 
                 NAME 
               
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Upper Die Set 
               
               
                 2 
                 Upper Cutting Tool 
               
               
                 4 
                 Large Forming Tool 
               
               
                 6 
                 Workpiece 
               
               
                 8 
                 Lower Die Set 
               
               
                 9 
                 Shim for Large Male Tool 
               
               
                 11 
                 Stripper 
               
               
                 12 
                 Small Forming Tool 
               
               
                 13 
                 Jam Nut 
               
               
                 14 
                 Shim 
               
               
                 15 
                 Spacer 
               
               
                 17 
                 Pressurized Cylinder 
               
               
                 19 
                 Lower Cutting Tool 
               
               
                   
               
            
           
         
       
     
       FIGS. 6-8  illustrate various aspects of a contour feature arrangement  20  (top elevation view,  FIG. 6 ) in a workpiece  6  and in stacked workpieces ( FIGS. 7-8 ) for inter-workpiece spacing. In  FIG. 7  the vertical cross sections of a nest of three workpieces  6  are shown, in which the registering contour features  30  of adjacent workpieces  6  are stacked on top of each other. A rim  34  in the registering contour feature  30  of one workpiece  6  underlies the rim of a registering contour feature in the workpiece positioned there above. Similarly, a concave, basin-shaped section  40  of one workpiece  6  underlies the corresponding concave section of a workpiece positioned there above. There is an interstitial space  46  between the rims  34  of adjacent workpieces. Optionally, other interstitial spaces  48  separate the concave sections  40  of adjacent workpieces. In a given workpiece, an inter-workpiece contact area  32  is formed between a rim  34  and the concave section  40 . In a stack of two or more workpieces  6 , the contact areas  32  abut. 
     In the cross sections of the embodiment depicted, there are two shoulders  34  that are connected by an annular rim  50  for each registering contour feature  30  and one concave, basin-shaped section  40 . Other embodiments may have more rims with rounded valleys therebetween. Like the rims  50 , the concave basin-shaped sections  40  are positioned so that concave sections of adjacent workpieces preferably are separated by the space  48  ( FIG. 7 ). As a result,  FIG. 8  shows exemplary gaps  36  or interstitial spaces lying between the workpieces  6  and between sets of registering contour features in a given workpiece. In practice, such gaps or interstitial spaces may be lessened or closed by the sagging of intermediate regions between registering contour features associated with stacked workpieces. 
     The air gaps  36  separate the workpieces  6  so that they can be removed from a stack one at a time and not adhere due to a fluid film therebetween. One set of experiments measured typical dimensions between workpieces  6  ( FIGS. 7-8 ). 
     Consider the upper die  1  and the lower die  8  in an open position before one of the workpieces  6  ( FIG. 2A ) is loaded, i.e. inserted therebetween. An outer annular rim-forming tool  4  is supported by the upper die  1 . The lower die  8  supports an inner basin-forming tool (having an optional shape like a button)  12 . If desired, these tools could be placed on the opposing die or upside down so that the upper die  1  may support the button tool and the lower die  8  may support the tool that forms the annular rim. 
     It will be appreciated that a given die set may support multiple tools  4 ,  12  so that multiple registering contour features may be formed on a given workpiece or workpieces  6  by one closure (or multiple closures) of the dies. Optionally, the process may operate in more than one place of a workpiece or on more than one workpiece at a time, subject to the design of the cutting die. In practice, one closure may operate on multiple workpieces simultaneously within the die, although one workpiece at a time is preferred. 
     As to the inner basin-shaped section  40 , in  FIGS. 3-4 , the upper and lower dies  1 ,  8  are in the stroke position. The small male insert  12  enters the large insert  4  to form a registering contour feature shape  30 . The spacer or jam nut  15  is now in contact with the bottom of the stripper  11  to control how deeply to make a small basin-shaped recess that forms a part of the registering contour feature. The small insert  12  is threaded into the jam nut  13  and the spacer  15 . The height of the small recess can be adjusted by adding or removing the thickness of the small shim  14 . It will be appreciated that the die still has to close more to cut the material with cutting tools  2 ,  19  as the registering contour feature is completely formed before the workpiece is cut. 
     Turning now to  FIG. 5 , the die is at the bottom of the press stroke. The stop block contacts the upper die  1 , thereby arresting its downward travel. Preferably, the workpiece  6  is now trimmed with the registering contour feature close to an edge of the workpiece. As used herein, the term “edge” connotes an outer peripheral edge, or an edge of an inner hole (for example, in the case of an automobile body having multiple holes cut for doors). 
     Desirably, registering contour features  30  of adjacent metal workpieces  6  are aligned (see,  FIGS. 6-7 ). After workpieces  6  are stacked, adjacent workpieces are separated by sets of registering contour features  30  because contacting portions  32  of the rim portions  34  of adjacent workpieces abut. Thus, an air gap  36  is created between the workpieces and between side portions  38  of the vertically aligned sets of registering contour features  30 . This facilitates material handling because lateral access to interstitial spaces is now available. 
     As mentioned earlier, the apparatus includes one or more sets of tools for forming the registering contour features  30 . Such tools may be selected to make registering contour features  30  with a topography that includes undulations, indentations, depressions, impressions, projections and the like in the workpiece. As noted earlier, one or more sets of registering contour feature forming tools can be located on the upper or lower dies ( FIGS. 1, 2, 2A ) or on both. 
     Thus, there has been disclosed a metal processing apparatus for forming one or more sets of registering contour features  30  in a workpiece  6  that may be made of a ferrous material, or a non-ferrous material such as a carbon-reinforced section or a plastic. 
     In one embodiment, the registering contour features  30  may be formed by nested basin-shaped portions  40  (concave sections) that have radii of curvature ( FIG. 7 ) such that spaces are formed between the shoulder portions  34  of the registering contour features of adjacent workpieces. Similarly, for basin-shaped portions  40 . ( FIG. 7 ). 
     It will be appreciated that using suitable process parameters (e.g., strain rates, temperatures, tool dimensions and pressures) the registering contour features can be pressed into the workpiece without weakening the workpieces themselves. 
     As noted earlier, the registering contour features can be characterized in a workpiece of a given thickness and material by a footprint having a height and diameter. The footprint can preferably be circular, oval, or elliptical. An indentation with a curved perimeter is generally desired over other geometries (e.g., a square, rectangle, a polygon) that have abrupt changes in perimetral edges. Usually, the footprint has a rim  34  (like the edge of a volcano) that lies above a crater or concave section or basin  40  (female portion), which may have another dome that rises there from. 
     With further references to  FIGS. 7-8 , an exemplary array of stacked workpieces  6  includes one or more workpieces in the stack having a planar section  44  and one or more registering contour features  30  extending from the planar portion. One or more of the registering contour features in a first workpiece has an outer annular rim  34  and an inner concave section  40  that lies within the annular rim. The outer annular rim  34  of the registering contour feature  30  of the first workpiece  6  cooperates with the outer annular rim in a registering contour feature of an adjacent workpiece. The inner concave section  40  in a registering contour feature of the first workpiece  6  cooperates with the inner concave section in a registering contour feature of an adjacent workpiece. As a result, a space  48  lies between planar portions of adjacent workpieces. Correspondingly, a space  46  may also lie between the shoulder portions  34  in a registering contour feature of the first workpiece and the shoulder portions in a registering contour feature of an adjacent workpiece. 
     In an alternative embodiment (see,  FIG. 7 ) the planar section  44  of one or more workpieces in the stack has a central plane that defines an imaginary datum plane (R-R). A top of the rim  34  lies above the imaginary datum plane and the inner concave section  40  has a lowermost portion that lies below the datum plane. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.