Abstract:
In a can forming machine a system that determines the position of a reciprocating ram and allows for the domer to be repositioned automatically is provided. The system includes a punch position sensor assembly, a control system, and a domer positioning assembly. The punch position sensor assembly is positioned about the ram, preferably at the domer side of the last die. At this location, the punch position sensor assembly can determine the position of the ram as it enters the dieback during the return stroke. The control system receives data from the punch position sensor assembly and, if the ram is not substantially, concentrically aligned with the die pack on the return stroke, sends a signal to the domer positioning assembly to reposition the domer. This process may be repeated until the ram travels along a path substantially aligned with the die pack on the return stroke.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The disclosed concept relates generally to a system structured to position a domer assembly so that a reciprocating ram is substantially concentrically aligned with a die pack during the return stroke of a ram and, more specifically, to a positioning system structured to detect the position of the ram during the reciprocal motion and to move the domer assembly dynamically. 
     2. Background Information 
     Generally, an aluminum can begins as a sheet of aluminum from which a circular blank is cut. The blank is formed into a “cup” having a bottom and a depending sidewall. The cup is fed into a bodymaker which passes the cup through additional circular dies that thin and elongated the cup. That is, the cup is disposed in front of the punch mounted on an elongated ram. The ram is structured to reciprocate and pass the cup through the circular dies which (re)draw and iron the cup. That is, on each forward stroke of the ram, a cup is passed through the circular dies which further form the cup into a can body. On the return stroke, the now elongated can body is removed from the ram and a new cup is disposed thereon. Following additional finishing operations, e.g. trimming, washing, printing, etc., the can body is sent to a filler which fills the can with product. A top is then coupled to, and sealed against, the can body, thereby completing the can. 
     More specifically, the die pack in the bodymaker has multiple, spaced dies, each die having a substantially circular opening. Each die opening is slightly smaller than the next adjacent upstream die. Thus, when the punch draws the cup through the first die, the redraw die, the aluminum cup is deformed over the substantially cylindrical punch. Because the openings in the subsequent dies in the die pack have a smaller inner diameter, i.e. a smaller opening, the aluminum cup is thinned as the ram moves the aluminum through the rest of the die pack. The space between the punch and the redraw die is typically less than about 0.010 inch and less than about 0.004 inch in the last ironing die. After the can has moved through the last die, the cup bottom and sidewall have the desired thickness; the only other deformation required is to shape the bottom of the cup into an inwardly extending dome. 
     That is, the distal end of the punch is concave. At the maximum extension of the ram is a “domer.” The domer has a generally convex dome and a shaped perimeter. As the ram reaches its maximum extension, the bottom of the can body engages the domer and is deformed into a dome and the bottom perimeter of the can body is shaped as desired; typically angled inwardly so as to increase the strength of the can body and to allow for the resulting cans to be stacked. As the ram withdraws, the can body then is stripped off of the end of the punch by injecting air into the center of the ram. The air comes out of the end of the punch and breaks the can body loose from the punch. Typically, there is also a mechanical stripper, which prevents the can body from staying on the punch it retracts back through the tool pack. The ram is withdrawn through the die pack, a new cup is deposited on the punch and the cycle repeats. 
     The ram and the die pack are typically oriented generally horizontally. This orientation, however, allows for wear and tear on the punch. That is, the dies in the die pack must be separated so as to allow for the proper deformation of the cup. This means that the ram must extend horizontally through the entire die pack; a distance that may be anywhere from 18 to 30 inches. This is also the stroke length for the bodymaker. This means that the ram is, essentially, a cantilevered arm. As is known, even a very rigid member supported as a cantilever will droop at the distal end. While this droop is generally not a problem for stationary members, the droop is a problem for a reciprocating ram passing through a die with a radial clearance of less than about 0.004 inch between the punch and the die. Typically, the domer is statically aligned to the punch, in order to compensate for the droop, however this alignment may not be correct for the dynamics of the ram in the machine. Also, there are other factors that can cause the punch not to run concentrically to the machine center line. Thus, because of the droop and other reasons, the ram may not be concentric with the circular dies, i.e. ram is closer to, or in contact with, the lower portion of the die. Over time, the contact between the punch and the die causes either of both to become damaged. When this happens, the damaged parts must be replaced. Further, because this is a time consuming procedure, and because a typical can forming machine produces over 15,000 cans an hour, having a misaligned ram is a disadvantage. That is, if the ram is misaligned, it is unlikely that any cans will be made. The ram should be aligned to the centerline of the machine (horizontally and vertically). 
     The position of the ram is also affected by the position of the domer. That is, the ram is brought into engagement with the domer and, if the domer is not properly aligned, will cause the ram to vibrate or otherwise be misaligned with the die pack. Given the narrow spacing between the punch and the dies, even a slight misalignment or slight vibration, may cause the punch to contact the dies. Generally, the domer is mounted on an adjustable assembly. Prior to using the can forming machine, and as part of regular maintenance, the domer is manually aligned with the ram. That is, the ram is placed at, or near, its maximum extension and the domer is aligned with the punch. This method, however, does not solve the problem of abnormal wear on the punch due to contact with the dies. That is, the position of the ram/punch at rest may not be the same as the position of the ram/punch in motion. Thus, a stated problem with the known systems and methods for aligning a punch with a die assembly is that the known systems and methods do not detect the position of the punch in motion. 
     SUMMARY OF THE INVENTION 
     The disclosed and claimed device provides for a system that determines the position of a punch as it retracts into a tool pack on a reciprocating ram and allows for the domer to be repositioned automatically. The system includes a punch position sensor assembly, a control system, and a domer positioning assembly. The punch position sensor assembly is positioned about the ram, preferably at the domer side of the last die. At this location, the punch position sensor assembly can determine the position of the punch as it enters the tool pack during the return stroke. The control system receives data from the punch position sensor assembly and, if the punch is not substantially, concentrically aligned with the tool pack on the return stroke, sends a signal to the domer positioning assembly to reposition the domer. This process may be repeated until the punch travels along a path substantially aligned with the tool pack on the return stroke. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is a schematic cross-sectional view of a can forming machine. 
         FIG. 2  is an isometric detailed end view of a can forming machine. 
         FIG. 3  is a schematic front view of one embodiment of the domer positioning system. 
         FIG. 4  is a schematic front view of another embodiment of the domer positioning system. 
         FIG. 5  is a cross-sectional side view of another embodiment of the domer positioning system. 
         FIGS. 6A-6H  are schematics showing different configurations of the domer positioning system shown in  FIG. 5 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As used herein, a “target position” is a selected position for the domer body center relative to the punch. The position is selected so as to cause the punch to be concentric with the tool pack upon the return stroke. This position may, or may not, be aligned with the axis of the ram or the axis of the tool pack. 
     As used herein, “dynamically positioning” means positioning a domer relative to the punch based on measurements acquired when the punch is in motion. This would include adjusting the domer while the punch is in motion as well as when the punch is motionless, so long as the measurements are acquired when the punch is in motion. 
     As used herein, “actively positioning” means positioning a domer relative to the punch when the punch is in motion. 
     As used herein, “coupled” means a link between two or more elements, whether direct or indirect, so long as a link occurs. An object resting on another object held in place only by gravity is not “coupled” to the lower object unless the upper object is otherwise maintained substantially in place. That is, for example, a book on a table is not coupled thereto, but a book glued to a table is coupled thereto. 
     As used herein, “directly coupled” means that two elements are directly in contact with each other. 
     As used herein, “fixedly coupled” or “fixed” means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other. The fixed components may, or may not, be directly coupled. 
     As used herein, the word “unitary” means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a “unitary” component or body. 
     As used herein, “associated” means that the identified components are related to each other, contact each other, and/or interact with each other. For example, an automobile has four tires and four hubs, each hub is “associated” with a specific tire. 
     As used herein, “engage,” when used in reference to gears or other components having teeth, means that the teeth of the gears interface with each other and the rotation of one gear causes the other gear to rotate as well. 
     As shown schematically if  FIG. 1 , a body maker, or can forming machine,  10  includes an operating mechanism  12  structured to provide a cyclical and/or reciprocating motion, a ram  14 , a die assembly  16 , and a domer assembly  18 . The ram  14  has an elongated, substantially circular body  19  with a proximal end  22 , a distal end  24 , and a longitudinal axis  26 . A punch  20  is disposed at, or over, the ram body distal end  24 . The punch  20  is a generally cylindrical body with a concave distal end which may be shaped to correspond to the domer assembly cavity  44 , discussed below. The ram body proximal end  22  is coupled to the operating mechanism  12 . The operating mechanism  12  provides a reciprocal motion to the ram body  19  causing the ram body  19 , and therefore the punch  20 , to move back and forth along its longitudinal axis  26 . That is, the punch  20  is structured to reciprocate between a retracted position and an extended position, the punch  20  extending and moving generally horizontally through the die assembly  16 . 
     The die assembly  16  includes at least one (three as shown) die(s)  30  (each) having an opening  32  therein. The opening  32  in the first die  30 A (the die  30  closest to the operating mechanism  12 ) is slightly larger than the opening  32  in the second (middle, as shown) die  30 B. The opening  32  in the second die  30 B is slightly larger than the opening  32  in the third (farthest from the operating mechanism  12 ) die  30 C. That is, the opening  32  in the first die  30 A has a radius that is about 0.010 inch larger than the radius of the punch  20 , the opening  32  in the second die  30 B has a radius that is about 0.007 inch larger than the radius of the punch  20 , and opening  32  in the third die  30 C has a radius that is about 0.004 inch larger than the radius of the punch  20 . The die assembly openings  32  are disposed along a common axis  34 . The die assembly axis  34  is generally aligned with the ram body longitudinal axis  26 . 
     In this configuration, the can forming machine  10  is structured to transform a cup into a can body, which may have a top added, forming a can. A cup is disposed over the punch  20 , typically when the punch  20  is in the retracted position. When the punch  20  pushes the aluminum disk through the die assembly  16 , the cup thinned and stretched to a desired length and wall thickness. The elongated cup is a can body. 
     The domer assembly  18  is disposed at the end of the ram body  19  stroke. The domer assembly  18  includes the domer die  40  and a movable mounting assembly  62  (discussed below). The domer die  40  is a body  42  with a cavity  44  defining a dome  46 . The domer body cavity  44  may include other features structured to shape the bottom of the cup. The center of the dome  46  is substantially aligned with the ram body longitudinal axis  26 . In this configuration, when the ram body  19  is at its maximum extension, the cup bottom, that portion of the cup extending over the punch  20 , is shaped by the punch  20  entering the domer body cavity  44 . That is, the cup bottom becomes an upwardly extending dome  46 . After the dome  46  is formed, the ram body  19  begins the rearward portion of the stroke. A can stripper (not shown) is disposed on the outer surface of the third die  30 C. The can stripper removes the can body from the punch  20 . Thus, the punch  20  travels rearwardly with no cup or other material between the punch  20  and the dies  30 A,  30 B,  30 C. 
     In this configuration it is possible for the punch  20  to contact the dies  30 A,  30 B,  30 C resulting in damage to the punch  20  and/or the dies  30 A,  30 B,  30 C. To prevent or reduce this damage, it is advantageous to have the ram body longitudinal axis  26  and the die axis  34  substantially aligned. That is, the punch  20  should not be vibrating or drooping. The punch  20 , disposed on the ram body distal end  24 , is prone to drooping as it is a cantilever body. Further, if the dome  46  is misaligned with the ram body longitudinal axis  26 , the punch  20  may be pushed out of alignment with the die axis  34  upon entering the domer cavity  44  and then rapidly returned, i.e. snapped, into alignment when leaving the domer cavity  44 . This action may cause the punch  20  to vibrate. While both the amount of droop and the misalignment caused by vibration are small, the tolerances between the punch  20  and the die openings  32  are sufficiently small so that any droop or vibration may cause contact between the punch  20  and the die openings  32 . 
     A domer positioning system  50  is structured to reduce the amount of contact between the punch  20  and the die assembly  16 . The domer positioning system  50  includes a punch position sensor assembly  52 , a control system  54 , and a domer positioning assembly  56 . The punch position sensor assembly  52  is structured to determine the moving configuration of the punch  20 . That is, a moving ram body  19  and the punch  20  disposed thereon may not droop in the same manner as a stationary ram body  19 , and/or, the moving ram body  19  may be vibrating. Thus, the punch position sensor assembly  52  is structured to determine the moving configuration of the punch  20  as it enters the die assembly  16  during the return stroke of the ram body  19 . Thus, the punch position sensor assembly  52  is preferably disposed at the third die  30 C and, more preferably, includes a plurality of sensors  59 , which are preferably inductive proximity sensors structured to provide an output signal proportional to the distance of the punch  20  from the sensor  59 , disposed about the outer side of the opening  32  in the third die  30 C, as shown in  FIG. 2 . The sensors  59  determine the position of the punch  20 , and more preferably the ram body distal end  24 , during the return stroke of the punch  20 . The punch position sensor assembly  52  is structured to convert the measurements into electronic data provided as a “punch moving configuration signal.” That is, the punch moving configuration signal includes data representing the punch  20  moving configuration. 
     The control system  54 , shown schematically in  FIGS. 1 and 3 , utilizes a programmable logic circuit (PLC) and a stored algorithm to analyze the punch moving configuration signal and to provide a domer target position signal. That is, the control system  54 , via its programming, is structured to relate the position of the moving punch  20  to a specific location of the domer body  42 . Based upon the location of the punch  20  during a return stroke, the control system  54  can determine the location of the domer body  42 . The control system  54  is further structured to determine a target position for the domer body  42  so as to place the punch  20  at a specific location during the return stroke. The specific location for the punch  20 , preferably, is entering the die assembly  16  in a substantially concentric relationship, i.e. having the ram body longitudinal axis  26  and the die assembly axis  34  substantially aligned. Thus, the control system  54  is structured to determine the present location of the domer body  42  based on the punch moving configuration signal and further structured to calculate a target position for the domer body  42  so as to place the punch  20  in a substantially concentric relationship to the die openings  32 . The data representing the target position for the domer body  42  is incorporated into a “domer target position signal.” 
     The domer target position signal is provided to the domer positioning assembly  56 . The domer positioning assembly  56  is structured to support the domer body  42 . The domer positioning assembly  56  is further structured to translate, i.e. move while maintaining the orientation of, the domer body  42  in a plane extending substantially perpendicular to the ram body longitudinal axis  26 . The domer positioning assembly  56  includes a fixed mounting  60 , a movable mounting assembly  62  and a drive assembly  64 . The fixed mounting  60  is structured to maintain its position relative to the die assembly  16  and, as shown, may be coupled thereto. The movable mounting assembly  62  is structured to support the domer body  42  with the cavity  44  facing the punch  20 . Further, the movable mounting assembly  62  includes a mount assembly having a first surface  70  and a second surface  72 , the first and second surfaces  70 , 72  being engagement surfaces. That is, the first and second surfaces  70 ,  72  are structured to be engaged by the drive assembly  64 . As discussed below, the engagement surface may be a coupling or, as in the preferred embodiment, the engagement surface may be a toothed surface. The drive assembly  64  includes a first motor  80 , a second motor  82 , a first engagement device  84 , and a second engagement device  86 . Each motor  80 ,  82  has a rotating output shaft  81 ,  83 , and each engagement device  84 ,  86  is coupled to an associated motor output shaft  81 ,  83 , and structured to engage an associated engagement surface  70 ,  72 . The drive assembly  64  may include a PLC, or similar device, structured to control the motors  80 ,  82 . Alternately, the motors  80 ,  82  may be structured to receive commands, via a signal, directly from the control system  54 . 
     The control system  54  further includes a position tracking assembly  90 . The position tracking assembly  90  is structured to track the position of the domer body  42  as the movable mounting assembly  62  moves. The tracking may occur optically, by position sensors (not shown) disposed between the fixed mounting  60  and the movable mounting assembly  62 , or by sensors  59  that track the position of the motor output shaft  81 ,  83 , or any other known device and associated method. The position tracking assembly  90  provides a domer position signal wherein the domer position signal includes data representing the current position of the domer body  42 . The domer position signal is communicated to the control system  54 . The control system  54  is further structured to compare the domer target position signal and the domer position signal, that is the control system  54  is structured to compare the actual position of the domer body  42  to the target position for the domer body  42 , and to continue actuating the drive assembly  64  until the domer body  42  is in the target position. That is, the control system  54  is structured to receive the domer position signal and to arrest the drive assembly  64  when said domer body  42  is disposed in the target position. 
     In one embodiment, the domer positioning assembly  56  is a plate extending in a plane generally perpendicular to the ram longitudinal axis  26  and structured to translate in its own plane. That is, the domer positioning assembly  56  includes one or more planar members (two as shown)  100 A,  100 B having at least two surfaces  102 ,  104 , the planar member at least two surfaces  102 ,  104  being the first and second surfaces  70 ,  72 . Preferably there are two planar members  100  movably coupled to each other. For example, the inner planar member  100 A closest to the fixed mounting  60  may include a substantially vertical groove (not shown) and the outer planar member  100 B may have a tongue (not shown) corresponding to the groove. 
     The planar member at least two surfaces  102 ,  104  are preferably two perpendicular surfaces, such as, but not limited to, two side surfaces on a rectangular plate. The first and second motor drive output shafts  81 ,  83  each have a threaded distal end  106 ,  108 . Each of the first and second engagement devices  84 ,  86  are jack screws  110 ,  112  each having a threaded bore  114 ,  115  structured to engage one of the first or second drive shafts  81 ,  83  a distal end  106 ,  108  and structured to be coupled to one of the first or second surfaces  102 ,  104 . That is, the jack screws  110 ,  112  may have a bracket  120 ,  122  or similar device structured to be coupled to the planar member  100 . The first jack screw  110  is threadably coupled to the first motor drive shaft  81  by its threaded bore  114 . The second jack screw  112  is threadably coupled to the second motor drive shaft  83  by its threaded bore  116 . The first jack screw bracket  120  coupled to the planar member first surface  102 . The second jack screw bracket  122  is coupled to the planar member second surface  104 . In this configuration, actuation of first motor  80  causes the first jack screw  110  to extend or retract relative to the first drive shaft  81  thereby causing the inner planar member  100 A to move along a first axis. Further, actuation of the second motor  82  causes the second jack screw  112  to extend or retract relative to the second drive shaft  83  thereby causing the outer planar member  100 B to move along a second axis. That is, the axes of the two motor drive shafts  81 ,  83  are preferably not parallel and are, more preferably, generally perpendicular to each other while disposed in a plane substantially aligned with, or parallel to, the plane defined by the planar members  100 A,  100 B. The planar members  100 A,  100 B may be disposed behind a frame  130 , or similar orienting device, structured to maintain each planar member  100 A,  100 B extending in a plane generally perpendicular to the ram longitudinal axis  26 . 
     In another embodiment, domer positioning assembly  56  includes two plates, a first plate structured to travel along one axis, e.g. vertical, and a second plate structured to travel along the other axis, e.g. horizontal. While these plates may be moved using a jack screw as described above, greater control may be provided with a worm gear as described below. In this embodiment, the domer positioning assembly  56  includes a first planar member  140  and a second planar member  142 . The first surface  70  being on the first planar member  140  and the second surface  72  being on the second planar member  142 . The first and second surfaces  70 ,  72  are, preferably, substantially straight and perpendicular to each other. Each movable mounting assembly planar member engagement surface, i.e. first and second surfaces  70 ,  72 , are preferably a toothed rack  146 ,  148 . 
     The first planar member  140  is movably coupled to the fixed mounting  60  and is structured to translate over a first axis. For example, the fixed mounting  60  may include a substantially vertical groove (not shown) and the first planar member  140  may have a tongue (not shown) corresponding to the groove. Similarly, the second planar member  142  is movably coupled to the first planar member  140  and is structured to translate over a second axis. Preferably, the second planar member  142  travel axis is substantially perpendicular to the first planar member  140  travel axis and is substantially parallel to the plane defined by said first planar member  140 . The first motor  80  is mounted on the fixed mounting  60  and the second motor  82  is mounted on the first planar member  140 . The drive assembly first engagement device  84  is a worm gear  150  positioned to engage the first planar member toothed rack  146 . The drive assembly second engagement device  86  is a worm gear  152  positioned to engage the second planar member toothed rack  148 . The second planar member  142  is structured to support the domer body  42  with the cavity  44  facing the punch  20 . 
     Because the ram body  19  is a cantilever body, it tends to flex radially about its supported end. That is, the displacement of the ram body distal end  24  typically occurs anywhere over a circular pattern. As such, the preferred embodiment of the domer positioning assembly  56  is structured to move the domer body  42  over a circular area. The domer positioning assembly  56  includes a housing  160 , which may be in the fixed mounting  60 , defining a rotational space  162  having an axis of rotation  164 , and the movable mounting assembly  62  includes a mount assembly  170  having a first substantially circular member  172  and a second substantially circular member  174 . The rotational space  162  may be defined by rollers (not shown), or a similar device, in a rectangular space, but is, preferably, defined by a cylindrical cavity  166  in the mount assembly  170 . The first circular member  172  is rotatably disposed in the rotational space  162  with the first circular member  172  center disposed substantially on the housing rotational space axis  164 . The first circular member  172  is structured to rotate about the rotational space axis of rotation  164 . The second circular member  174  is rotatably coupled to the first circular member  172 , but the second circular member  174  center is radially offset from the first circular member  172  center. As before, the drive assembly  64  has a first motor  80  and a second motor  82 , each motor  80 ,  82  having a rotating output shaft  81 ,  83 , each motor output shaft  81 ,  83  is structured to engage, and rotate, one of the first or second circular members  172 ,  174 . 
     More specifically, the first circular member  172  includes the first engagement surface  70  and the second circular member includes the second engagement surface  72 . The first and second engagement surfaces  70 ,  72  are, preferably, toothed racks  176 , 178  disposed near, or preferably on, the radial surfaces of the first and second circular members  172 ,  174 . As before, each drive assembly motor  80 ,  82  include a first engagement device  84  and a second engagement device  86 , respectively. The engagement devices  84 ,  86  in this embodiment are a first and second worm gear  180 , 182  each disposed on an associated motor output shaft  81 ,  83  and structured to engage the associated engagement surface  70 ,  72 . That is, the first worm gear  180  is structured to engage the first circular member toothed rack  176  and the second worm gear  182  is structured to engage the second circular member toothed rack  178 . 
     If the domer body  42  was mounted on a single circular member  172 ,  174 , and not disposed on the axis of rotation, the domer body  42  could be moved in a circle about the axis of rotation. By providing two circular members  172 ,  174  moving relative to each other (that is, having offset axes), and by having the center of the domer body  42 , i.e. the center of the dome  46  offset from the center of the second circular member  174 , the domer body  42  may be positioned anywhere within a circle defined by the maximum radii of the two circular members  172 ,  174 . This does, however, create a problem in that the center of the second circular member  174  does move in a circle as the first circular member  172  rotates. This, in turn, means that the perimeter of the second circular member  174 , where the second circular member toothed rack  178  is located, also moves. This means that the second worm gear  182  must accommodate the motion of the second circular member toothed rack  178  about the center of the first circular member  172 . One solution would be to mount the second motor  82  on the first circular member  172 , thereby keeping the second worm gear  182  and the second circular member toothed rack  178  in a constant relationship. 
     In the preferred embodiment, however, the first and second motors  80 ,  82  are mounted on the fixed mounting  60  and the two circular members  172 ,  174  have about the same diameter. The second worm gear  182  maintains engagement with the second circular member toothed rack  178  by having an extended tooth. That is, as noted above, the gap between the punch  20  and the die openings  32  is very small. Similarly, the amount that the domer body  42  must be adjusted is very small. This means that the amount of offset between the first and second member  172 ,  174  axes of rotation is also very small. When a worm gear rack radius is substantially larger than the worm gear radius, the lateral sides of the worm gear still engage the sides of the rack teeth even as the rack moves slightly away from the worm gear. Thus, this configuration still allows for precise control of the position of the two circular members  172 ,  174  even when the second circular member  174  moves relative to the second worm gear  182 . 
     In this configuration, motion from the first motor  80  is transferred to the first circular member  172  via the engagement of the first engagement device  84  with the first engagement surface  70 , and, motion from the second motor  82  is transferred to the second circular member  174  via the engagement of the second engagement device  86  with the second engagement surface  72 . 
     While the second circular member  174  may be mounted on an axle (not shown) extending from the first circular member  172 , in the preferred embodiment, the first circular member  172  has a circular opening  190  therein. The center of the first circular member opening  190  is offset from the center of the first circular member  172 . The second circular member  174  has a cylindrical portion  192  and a flange  184  at one end. The second circular cylindrical portion  192  is sized to fit snugly, but rotatably, within the first circular member opening  190 . The second circular member flange  184 , preferably, has a radius substantially the same as the radius of the first circular member  172 . In this configuration, the second circular member cylindrical portion  192  may be disposed in the first circular member opening  190 , while the second circular member flange  184 , which is longitudinally offset from the first circular member  172 , may be engaged by a worm gear  182  on a motor  82  coupled to the fixed mounting  60 . Further, the second circular member  174  also has an offset, substantially circular opening  194  therein. The domer body  42  is disposed in the second circular member circular opening  194 . As discussed and shown below, positioning the two circular members  172 ,  174  at different orientations allows for the domer body  42  to be placed in the target location. 
     The offset between the first circular member  172  center and the first circular member circular opening  190  center is between about 0.005 and 0.020 inch, and more preferably about 0.015 inch, and, the offset between said second circular member  174  center and said domer body  42  center is between about 0.005 and 0.020 inch, and more preferably about 0.015 inch. The position of the center of the domer body  42  relative to the first circular member axis of rotation may be expressed in Cartesian coordinates by the equations: 
     x i,j :=e1·sin(a 1 ·deg)+e2·sin(β j ·deg) which is the resultant X position of the center of the domer body  42 . 
     y i,j :=e1·cos(a 1 ·deg)−e2·cos(β j ·deg) which is the resultant Y position of the center of the domer body  42 . 
     wherein: 
     e1:=first circular member  172  eccentricity, preferably 0.015 in. 
     e2:=second circular member  174  eccentricity, preferably 0.015 in. 
     i:=range of angular displacement in degrees (0, 1 . . . 359) 
     j:=range of angular displacement in degrees (0, 1 . . . 359) 
     α i :=i first circular member  172  angular displacement 
     β j :=j second circular member  174  angular displacement 
     As shown in  FIGS. 6A-6H , different orientations for the two circular members  172 ,  174  are shown as well as the position of the second circular member circular opening  194 . For example, the two circular members  172 ,  174  may each include an indica  196 ,  198  indication the orientation of each circular member  172 ,  174 . In  FIG. 6A , the two circular members  172 ,  174  are positioned at an orientation identified as “0°” The offset of the center of the second circular member circular opening  194 , which is the same as the position of the center of the domer body  42 , is offset upwardly from the center of the rotational space axis of rotation  164 . In  FIG. 6B , and as indicated by the indicia  196 ,  198 , the first circular member  172  has been rotated 120° is one direction and the second circular member  174  has been rotated 75° in the opposite direction. Now, the offset of the center of the second circular member circular opening  194  is downwardly and to the right from the center of the rotational space axis of rotation  164 . Other configurations of the two circular members  172 ,  174  are shown in  FIGS. 6C-6H  as indicated on each Figure. 
     The domer positioning assembly  56  may further include a clamping device  200 . The clamping device  200  is structured to arrest the motion between the movable mounting assembly  62  and the fixed mounting  60 . Typically, the domer positioning system  50  is utilized prior to running the can forming machine  10  so as to calibrate the position of the punch  20  relative to the die openings  32 . This may be performed with or without a cup disposed on the punch  20 . Typically, this would be performed by running a single cycle of the operating mechanism  12  to determine the position of the moving punch  20  relative to the die openings  32 , then adjusting the position of the domer body  42 , and running another single cycle of the operating mechanism  12 . This type of positioning the domer body  42  is identified as dynamically positioning the domer body  42  as the punch  20  is in motion during the process. It is, however, possible to have the domer positioning system  50  in constant operation, that is, adjusting the position of the domer body  42  while the operating mechanism  12  is in constant use and the punch  20  is constantly moving. This type of positioning is identified as actively positioning the domer body  42 . 
     While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.