Patent Publication Number: US-2009224021-A1

Title: Apparatus and method for processing coiled sheet-like material

Description:
FIELD OF THE INVENTION 
     The present invention relates to coil processors and, more particularly, to apparatus and methods for processing coils of sheet-like material that include conveyors for transporting the sheet-like material, tool carriages with tools for performing work operations on the sheet-like material, and control units for controlling movement of the conveyor, tool carriages and individual tools. 
     BACKGROUND INFORMATION 
     In mechanical engineering, industrial engineering, and other fields, it is often advantageous to process sheet-like material, such as sheet metal or plastic sheet, that is stored in coils. Because the material is originally coiled, and not flat, greater amounts of the material can occupy smaller unit areas in factories or other locations where space is often at a premium, and the material may be transported to the processing site more easily and inexpensively than flat sheet-like materials. 
     Methods and apparatus for processing coiled sheet-like material exist in the prior art. Such methods and apparatus generally contemplate unrolling and straightening the coiled material, conveying the straightened material forward through a processor in a first longitudinal direction, and processing the straightened material, before preparing the processed end-product for packaging or further processing. Typical processing applications can include cutting, punching, stamping, bending and/or other operations. 
     One of the drawbacks of prior art methods and apparatus for processing coiled sheet-like materials is that the rate of production of the processed end product depends at least in part upon the rate of unrolling of the material from the coil. As a result, any disruption to the unrolling process can reduce the efficiency of processing or production. Additionally, the production rate can be limited by the size of the coil roll, which must be replaced when the material is entirely uncoiled. If the desired processing operation is to occur along varying longitudinal axes in the uncoiled material, the production rate can be further limited by the capacity of the processing unit. If the processing unit cannot move in a second transverse direction with respect to the material, then the coil processor may only perform a single processing operation on the longitudinally moving material passing through the processor. If the processing unit can move in the second transverse direction, the production rate still can be limited by the complexity of the desired processing operation or the comparative rate of motion of the material in the first direction and the processing head(s) in the second direction. At times, temporarily slowing or halting the unrolling of the sheet-like material may be required to enable the processing head to be placed in the appropriate position, in order to accomplish certain processing operations. 
     Additionally, although the art of “coil processing” contemplates several different types of operations, including cutting, punching, stamping, bending and/or other operations, prior art coil processors may be limited to a single processing operation. In many applications, processing units that can perform multiple functions are preferable to those units that can perform only a single function. 
     Several existing coil processing units demonstrate both the advantages and the limitations of the prior art. For example, U.S. Pat. No. 3,628,367 to Wilg, entitled “Scroll Cutting and Slitting Machine with Tension Control Means,” shows a coil processor including a straightening device, a pair of punching and slitting dies, and a tension means for controlling the basic line speed of the stock material. One of the drawbacks of this type of coil processor is that the punching and slitting dies cannot move transversely relative to the conveyed sheet-like material, and thus cannot perform processing operations on the sheet material in multiple longitudinal axes. Yet another drawback of this type of processor is that it is limited to punching and slitting operations only. Other exemplary prior art coil processors are described in the following patents: U.S. Pat. Nos. 6,742,239 and 6,484,387 to Lee et al., entitled “Progressive Stamping Die Assembly Having Transversely Movable Die Station and Method of Manufacturing a Stack of Laminae Therewith,” and U.S. Pat. No. 6,563,081 to Pace, entitled “Process for the Laser and/or Plasma Cutting of Strips, Particularly Metal Coils, and Relative Continuous Cutting Lines.” 
     It is an object of the present invention to overcome one or more of the above-described drawbacks and/or other disadvantages of the prior art. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect, the present invention is directed to an apparatus for processing sheet-like material, such as sheet metal or plastic sheet. The apparatus comprises a number of components connected in series, including a coil, a straightener, a processor and a conveyor, which moves the material in a first longitudinal direction through each of the components after uncoiling. Additionally, a slack region exists between two of the units, and acts as a material accumulation buffer to permit the processing of the material and the uncoiling of the material to occur independently. 
     The processing unit can perform a variety of different processing operations, and includes at least one tool carrier which can move in a second transverse direction above the material as it is conveyed through the processing unit. The tool carriers can carry one or more tools which can independently perform cutting, punching, stamping, bending and/or other operations on the material as it passes through the processing unit. The present invention can employ either a single tool carrier or multiple tool carriers to perform processing operations. 
     In the present invention, the movement of the material and the tool carrier(s) and the operation of the individual tools is controlled by a control unit, which can be operated either manually or automatically. When operated automatically, the control unit uses a computer to calculate the most efficient sequence of performing the desired processing pattern, in order to maximize processing efficiency. Desired processing patterns are loaded into the computer and analyzed; the control unit will determine the most efficient sequence for processing the material in accordance with the desired pattern. The most efficient sequence is generally that which minimizes the transverse movement of the tool carrier(s) and utilizes the conveyor&#39;s ability to move the material forward or backward through the processing unit, as necessary. 
     In accordance with a second aspect, the present invention is directed to a method for processing coiled sheet-like material, comprising feeding such material from a rotatably mounted coil through a processing unit using a tool that moves transversely relative to the movement of the material, to perform work. The method also comprises forming a slack in the material downstream of the coil, and moving the material forward or backward through the processing unit as necessary. The method further comprises using a computer to determine the most efficient sequence for performing a desired processing pattern; the computer considers the pattern to be performed, the longitudinal motion of the material to be processed and the transverse motion of the moving tool in the forward and backward directions in calculating the optimal processing sequence. 
     In some embodiments of the present invention, the method further comprises the steps of (i) defining a pattern of work operations of the tool(s) on the sheet-like material transported by a conveyor, and (ii) determining for each of a plurality of steps in a first coordinate direction the total movement of the first and second tools in a second coordinate direction for one or more of the following scenarios: (a) movement of first and second tool carriages toward each other, (b) movement of first and second tool carriages in the same direction toward a first side of the sheet-like material, and (c) movement of first and second tool carriages in the same direction toward a second side of the sheet-like material. Some embodiments of the present invention further comprise the step of determining the location of the first and second tools after completing one or more of scenarios (a), (b) and (c) involving the least amount of travel in the second coordinate direction. 
     Some embodiments of the present invention further comprise the steps of straightening the sheet-like material fed from the coil; and defining a limit of backward movement of the sheet-like material in the first coordinate direction that prevents a need to move sheet-like material in the straightener backwardly in the first coordinate direction. In some such embodiments, the method further comprises the steps of determining the limit of backward movement in the first coordinate direction by determining the processing steps of first and second tools without allowing any backward movement of the conveyor in the first coordinate direction, and then performing multiple iterations of the processing steps of the first and second tools beginning with a minimum of backward movement of the conveyor to a maximum of backward movement of the conveyor with predetermined increments therebetween. Preferably, the method further comprises the steps of determining whether any tools will collide, and if so, moving one or more of the tools relative to the other(s) to avoid collision, performing all of the moves for the other tool(s) in the second coordinate direction, and if necessary to avoid collision, doing the same for the other tools. 
     In accordance with another aspect, the apparatus further comprises at least one rotatably mounted tool, a motor for rotatably driving the tool, a ring gear drivingly connected to the tool, and a worm gear drivingly connected between the ring gear and the motor. The worm gear includes first and second portions, and at least one of the first and second portions is biased into engagement with the ring gear to substantially prevent backlash of the worm and/or ring gears. 
     Among the advantages of the present invention is that the sheet-like material can move both backward and forward in the first longitudinal direction during processing operations. Depending on the desired processing operation, it may be advantageous to change the rate and direction of material travel into the processing unit, in order to perform the desired pattern more efficiently. The capacity to move material both backward and forward can increase processing efficiency over methods and apparatus in the prior art because delays associated with the movement of tool carriers may be minimized. In this regard, the motion of the tool carrier need not limit the rate of processing. 
     Another advantage of the present invention is its capacity to accumulate slack in the material during processing operations. The accumulation of slack in a loop situated downstream of the uncoiler enables the material to continue uncoiling even while material is also moving in the backward direction through the processing unit. The accumulation of slack is thereafter reduced when material is advanced through the processing unit in the forward direction at a rate that exceeds the rate of uncoiling. 
     A further advantage of the currently preferred embodiments of the present invention is that the tool carrier(s) may perform multiple processing operations independently or simultaneously. The tool carrier(s) of the present invention feature multiple independent processing tools for performing punching, shearing, bending, slitting or other similar operations, along with a rotating tool die head for performing cutting, routing or other similar operations. The mobile tool carriers and the variety of tools housed therein enable the processor to complete complex processing applications and also to perform a wide variety of processing operations without having to replace tools. Additionally, the tool carriers can also reposition the tools in the second transverse direction perpendicular to the material passing through the processing unit. 
     Yet another advantage of the currently preferred embodiments of the present invention is that the use of multiple tool carriers enables the processor to complete processing operations more quickly and efficiently than a processor with only one tool carrier. 
     Other objects and advantages of the present invention will become readily apparent in view of the following detailed description of currently preferred embodiments and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side elevational view of a coil processor of the present invention showing the uncoiler, the straightener, the slack region, the conveyor and the processor. 
         FIG. 1B  is a top plan view of the coil processor of  FIG. 1A . 
         FIG. 2A ,  FIG. 2B ,  FIG. 2C  and  FIG. 2D  are top plan, side elevational, front elevational and rear elevational views, respectively, of a C-shaped tool carrier of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 3A  and  FIG. 3B  are top plan and side elevational views of the tooling carriage and showing tool dies of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 4A ,  FIG. 4B  and  FIG. 4C  are a top plan view and elevational views of the front and rear, respectively, of the cylinder manifold of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 4D  and  FIG. 4E  are side elevational views of the cylinder manifold of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 5A ,  FIG. 5B  and  FIG. 5C  are top plan, rear and side elevational views, respectively, of the rotating tool die carriage of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 6A  and  FIG. 6B  are side elevational and top plan views, respectively, of the rotating tool die of the coil processor of  FIG. 1A  and  FIG. 1B . 
         FIG. 7A  and  FIG. 7B  are a two-part flow chart illustrating the procedural steps performed by the coil processor software in the preferred embodiment, to determine the most efficient processing sequence, in accordance with a method of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE CURRENTLY PREFERRED EMBODIMENTS 
     In  FIGS. 1-6  a coil processor embodying the present invention is indicated generally by the reference numeral  10 . The apparatus  10  comprises a plurality of components in series. A coil  12  containing coiled sheet-like material is positioned within an uncoiler assembly  16 , which permits the coiled material to rotate and feed therefrom in a longitudinal or x-coordinate first direction toward a straightener  20 , which is positioned to straighten the sheet-like material after it is unrolled from the uncoiler assembly  16 . The straightened material leaving the straightener  20  is then fed in the x-coordinate direction to a conveyor unit  30 , which translates the material either forward or backward in the x-coordinate direction. Material leaving the conveyor unit  30  enters into the processing unit  32 , which includes at least one tool carrier  34 , and undergoes the desired processing operation(s) within the processing unit  32 . The processed material may then be prepared for storage, shipping or further processing. 
     The uncoiler assembly  16  comprises a coil  12  with a right cylindric shape and around which sheet-like material is wrapped. The coil  12  is mounted onto a coil carrier assembly  14  such that the coil  12  can rotate about its axis. The uncoiler assembly  16  uncoils and feeds the sheet-like material in the direction of the straightener  20 . In a preferred embodiment, the coil carrier assembly  14  is mounted onto wheels, tracks or other traveling apparatus, such that the coils can be unloaded and replaced when the sheet-like material has been fully uncoiled or otherwise when desired. Additional coil carrier assemblies  14  may be positioned near the apparatus  10  during operation, such that when the sheet-like material has been fully uncoiled or otherwise requires replacement, the coil carrier assembly may be removed and replaced with another or full coil carrier assembly. 
     Because the sheet-like material enters the apparatus after having been uncoiled, it will typically have an arcuate shape of varying degree upon exiting the uncoiler assembly  16 . The straightener  20  is located downstream of, and receives the sheet-like material fed from the uncoiler assembly  16 . In the illustrated embodiment, and by way of a non-limiting example, the material leaving the uncoiler assembly is fed in the direction of the straightener  20  on a ramped roller top table assembly  18 . The straightener  20  may comprise a plurality of continuously opposed rollers linked in series, which combine to straighten the sheet-like material as it passes between them, or other apparatus or methods of straightening coiled sheet-like material that are currently known, or that later become known, to those of ordinary skill in the pertinent art. After leaving the straightener  20 , the straightened material is then fed in the x-coordinate direction toward the conveyor unit  30 . In the illustrated embodiment, and by way of a non-limiting example, the material exits the straightener  20  onto a straightener bridge table assembly  22 , which typically comprises a table including a plurality of rollers descending away from the straightener  20 . 
     A slack region  24  is located between the straightener  20  and conveyor unit  30 . The slack region  24  permits the rate of material fed into the processing unit  32  to vary, both forward and backward in the x-coordinate direction, largely independent of the rate of uncoiling from the uncoiler assembly  16 . In the illustrated embodiment, and by way of a non-limiting example, the sheet-like material enters the slack region  24  descending onto the straightener bridge table assembly  22 , sags into a loop or downwardly directed arcuate shape in the slack region  24 , and exits the slack region  24  onto the feeder bridge table assembly  28 , ascending in the direction of the conveyor unit  30 . If the rate of material fed into the processing unit  32  is less than the rate of uncoiling from the uncoiler assembly  16 , the loop in the slack region  24  will deepen as the sheet-like material builds up or accumulates therein. If the rate of material fed into the processing unit  32  exceeds the rate of uncoiling from the uncoiler assembly  16 , the depth of the loop will be reduced as the material is conveyed out of the slack region  24  and into the processing unit  32 . Thus, the slack region  24  acts as a buffer for accumulating material, and enables the processing unit  32  to perform precise operations on the material without affecting the rate of uncoiling from the uncoiler assembly  16 . The slack region  24  includes a monitoring unit  26  for monitoring the depth of the loop and transmitting signals indicative thereof to the control unit  38 . The monitoring unit  26  may be any of numerous different types of such monitoring units that are currently known, or that later become known, to those of ordinary skill in the pertinent art. 
     The conveyor unit  30  controls the rate at which the sheet-like material is fed into the processing unit  32 . In the illustrated embodiment, and by way of a non-limiting example, the sheet-like material enters the conveyor unit  30  from the feeder bridge table assembly  28 . Depending on the processing operation to be performed within the conveyor unit  30 , it may be advantageous to change the rate or direction of material travel through the processing unit  32 . The conveyor unit  30  can move material either forward or backward in the x-coordinate direction, and is designed to operate independently from the uncoiling of material from the uncoiler assembly  16 . 
     The processing unit  32  is located downstream of the conveyor unit  30 , and is comprised of at least one C-shaped tool carrier  34 , which can perform various processing operations, including cutting, punching, stamping, bending and/or other operations on the sheet-like material as it is conveyed through the processing unit  32 . In the illustrated embodiment, and by way of a non-limiting example, the material leaving the processing unit  32  travels along a conveyor table assembly  36 , where the material is packaged or otherwise prepared for distribution or further processing. 
     As shown in  FIGS. 2A ,  2 B,  2 C and  2 D, the coil processor  10  includes two C-shaped tool carriers  34  positioned on opposite sides of the conveyor relative to each other, and configured to move in the transverse, or y-coordinate, direction relative to the sheet-like material as it passes through the processing unit  32 . The tool carriers  34  can move in the y-coordinate direction either independently of each other or together in order to perform any of a plurality of different processing operations. In the illustrated embodiment, and by way of a non-limiting example, tool carriers  34  are positioned on linear bearings  68  with individual servo drive motors (not shown). However, other methods of positioning the tool carriers  34  that are known, or may become known, may be used to perform the positioning function. 
     Although the preferred embodiment includes two tool carriers  34 , any number of tool carriers of any of numerous different configurations that are currently known, or that later become known, may be employed. For example, a single tool carrier may be employed if desired, or alternatively, multiple pairs of tool carriers may be employed in series if the desired operations require such a configuration. 
     The tool carriers  34  can perform a number of different functions in order to accomplish the desired processing of the sheet-like material. As shown in  FIGS. 2A ,  2 B and  2 C, the tool carriers  34  are connected to electrical, hydraulic and other services for use during coil processing, and can accommodate different processing apparatus, such as the tooling carriage  42  and the rotating die tool carriage  40 . Because the tool carrier  34  can operate with interchangeable apparatus, it can perform a variety of different processing operations on sheet-like materials of different shapes, sizes, thicknesses and types. Each tool carrier  34  can process sheet-like material using either the tooling carriage  42  or the rotating tool die carriage  40  independently, or by using both components simultaneously. 
     Punching, shearing and similar processing operations may typically be performed with the tooling carriage  42 , which includes a plurality of tool dies  46  and is mounted to the base plate of the cylinder manifold  44 . The cylinder manifold  44  includes internal hydraulic piping, valves and other components that enable the independent operation of the tool dies  46 . In the illustrated embodiment of the present invention, and by way of a non-limiting example, the cylinder manifold  44  and tooling carriage  42  can accommodate up to ten different tool dies  46 , which can be actuated independently. Because the tooling carriage  42  can accommodate multiple tools, the coil processor  10  can accomplish a number of different processing tasks without adjusting or replacing the carriage(s). However, in order to minimize processing downtime, separate tooling carriages  42  may be readied independent of the processor operation so that they may be installed into the tool carrier  34  if necessary. 
     The tooling carriage  42  is installed into the tool carrier  34  by mating the tool dies  46  in the carriage with the respective cylinders  64  of the cylinder manifold  44  mounted in the upper interior surface of the tool carrier  34 . If desired, each tool die  46  can be connected to electrical power, hydraulic power and/or other power sources or services independently of the tool carrier  34 . The cylinder manifold  44  contains internal hydraulic lines and valves which provide sufficient hydraulic pressure to permit each cylinder  64  to be actuated independently, and to perform the desired processing operation. Once actuated, each cylinder  64  presses the respective tool die  46  downward in a third or z-coordinate direction substantially perpendicular to the plane of the material travel through the processing unit  32 . In this manner, each tool die  46  can independently perform punching, shearing and/or other operations on the sheet-like material. 
     As shown in  FIGS. 3A and 3B , the illustrated embodiment of the tooling carriage  42  includes ten tool dies  46  of varying sizes, shapes and functions. As shown in  FIG. 4D  and  FIG. 4E , each cylinder  64  in the cylinder manifold  44  includes hydraulic supply lines  48  and hydraulic return lines  50  which enable each of the cylinders  64  to be extended or retracted independently of each other. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the cylinder manifold  44  and tooling carriage  42  may include any number of cylinders  64  and tool dies  46  that are desired or otherwise required, and may include any of a variety of different types of tools for processing the sheet-like material that are currently known, or that later become known, to those of ordinary skill in the pertinent art. 
     Turning to  FIGS. 5A ,  5 B and  5 C, the rotating tool die carriage  40  is generally used to perform cutting, grinding, routing and/or other desired operations on the sheet-like material. The rotating tool die carriage  40  is installed into the respective tool carrier  34  by connecting it with a single hydraulic cylinder  70  or other apparatus, which drives the rotating tool die in the z-coordinate direction. Typically, the rotating tool die carriage  40  features a single tool, such as a blade or other cutting device, which is placed into the appropriate position in the z-coordinate direction by the cylinder  70 . In order to maintain precise control over the tool depth during processing operations, the cylinder  70  in the rotating tool die carriage  40  contains servo-actuated hydraulic valves (not shown) which position the tool in the z-coordinate direction to a desired degree of accuracy. This function may be performed by other apparatus that are currently known, or that later become known, to those of ordinary skill in the pertinent art. As may be recognized by those or ordinary skill in the pertinent art based on the teachings herein, the rotating tool die carriage  40  may include any of a variety of different tools and/or different tool types that are currently known, or that later become known, for performing any of a variety of different work operations on sheet-like material. 
     As shown in  FIGS. 5A ,  5 B,  5 C and  6 A, the rotating tool die carriage  40  includes an upper rotating head  54  and a lower rotating head  56 , which are substantially synchronously rotated by a servo motor  52  or other type of drive unit that is currently known, or that later becomes known, to those of ordinary skill in the pertinent art for performing this function. As shown in  FIGS. 5B and 5C , in the illustrated embodiment, the servo motor  52  is drivingly connected to the upper rotating head  54  and a lower rotating head  56  by a pair of shafts  60 . A pulley system comprising at least one pulley  58  is used to transfer rotational energy from the servo motor  52  to the individual shafts  60 . 
     As shown in  FIG. 6B , one end of each of the shafts  60  is respectively coupled to the upper rotating head  54  and a lower rotating head  56  by worm gears  62 A,  62 B which are positioned near the ends of the shafts  60 , and positively bias against the ring gear  66 . A tool, such as a blade or other processing device, is mounted to the upper rotating head  54 , and is pressed into the appropriate processing position in the sheet-like material in the z-coordinate direction by the cylinder  70 . The lower rotating head  56  defines a slot having a shape substantially identical to that of the respective tool, but a size slightly larger than that of the tool so that the tool may enter the slot if it partially or fully penetrates the sheet-like material during processing. 
     The rotational position of the slot in the lower rotating head  56  must approximately match the rotational position of the tool installed into the upper rotating head  54 , to enable the tool to insert into the slot upon partial or full penetration of the sheet-like material. Therefore, the rotation of the heads is preferably synchronized, using a servo motor  52  and pulley system as described above, or other apparatus known, or that may become known, to those skilled in the pertinent art. To accomplish this function, the worm gear  62 A,  62 B on the respective shafts  60  maintains a substantially constant bias on the ring gear  66  on the respective rotating heads  54 ,  56  to minimize backlash. In the illustrated embodiment, and as shown in  FIG. 6B , the worm gear  62 A,  62 B is split approximately in half; the inner half of the worm gear  62 A is appropriately positioned on the ring gear  66  during assembly of the gearset, after which the outer half of the worm gear  62 B is installed along with a gear spring (not shown), which maintains the halves of the worm gear  62 A,  62 B substantially in contact with the ring gear  66 . However, other methods and apparatus for minimizing the backlash on the worm gear  62 A,  62 B and ring gear  66  may be utilized, including those that are currently known, or that later become known, to those of ordinary skill in the pertinent art. 
     One advantage of the coil processor  10  is that its components, including tool carriers  34 , independent tool dies  46 , conveyor unit  30 , and others if desired, can operate either manually at the direction of a human operator, or automatically as directed by the control unit  38 , to perform any of a variety of desired processing operations. The control unit  38  includes software that determines the most efficient sequence to accomplish the desired processing operations by controlling the material feed rate in the x-coordinate direction, the lateral movement of the tool carriers  34  in the y-coordinate direction, and the operation of the individual tool dies  46  of the tool carriage and/or the single tool die  46  in the rotating tool carriage in the z-coordinate direction when performing processing operations. 
     Turning to  FIG. 7 , the software resident on the control unit  38  determines the most efficient processing sequence for performing the desired processing pattern. In the illustrated embodiment, at the outset of operations, as is shown in step S. 1 , pattern data is programmed into the control unit  38 , such as by manual entry via a keyboard, mouse or other data input apparatus; transfer from floppy discs, CD-ROMs, DVD-ROMs, external hard drives, RAM drives or other data storage devices; by download from external data sources such as the Internet or an internal computer network (“Intranet”); or by any of numerous other apparatus or methods that are currently known, or that later become known. In the preferred embodiment, two tool carriers  34  are directly opposed to one another on either side of the sheet-like material passing through the processor unit  32 , and a central processing unit (CPU)  72  of the control unit  38  utilizes the onboard software and the data entered to optimize the desired processing pattern in a sequence as hereinafter described. 
     In step S. 2 , optimizing software breaks down the desired processing pattern into movements of each tool carrier  34  in the y-coordinate direction for every position of the material in the x-coordinate direction. Each collection of individual tool carrier  34  movements in the y-coordinate direction at a single material position in the x-coordinate direction is analyzed, for each step of the pattern. Next, in step S. 4 , the CPU calculates the total movement required by the tool carriers  34  in the y-coordinate direction to complete the desired operations at the initial material position in the x-coordinate direction at the beginning of the desired pattern, for at least the following carrier movement scenarios: (i) movement of the tool carriers  34  inward toward each other; (ii) movement of the tool carriers  34  in the same direction toward one side of the sheet-like material; and (iii) movement of the tool carriers  34  in the same direction toward a second side of the sheet-like material. In step S. 5 , the CPU  72  chooses the scenario in which the aggregate movement of the tool carriers  34  is minimized while accomplishing the desired processing operation for the first material unit step of the processing pattern in the x-coordinate direction. 
     After a carrier movement scenario is originally selected, the CPU  72  then determines in step S. 6  where the tool carriers  34  must be positioned in the y-coordinate direction in order to perform the desired processing operation at the next material location in the x-coordinate direction. If the scenario originally selected by the CPU  72  would leave the tool carriers  34  in a position that would require excessive movement (or movement greater than a predetermined distance or other amount) to perform the desired processing operation at the next material location in the x-coordinate direction, the CPU  72  will return to step S. 5  and revisit its selection, to consider whether either of the remaining two scenarios identified, for example, as (i), (ii) and/or (iii) above would place the tool carriers  34  in a more optimal position to accomplish the next processing operation. If either scenario would provide less movement of the tool carriers  34  to perform the desired processing operation at the next material unit step in the x-coordinate direction, the CPU  72  will abandon its original selection and choose one of the two remaining scenarios which was not originally selected. If neither of the two remaining scenarios would improve the position of the tool carriers  34  to accomplish the processing operation at the next material unit step in the x-coordinate direction, the CPU  72  will adhere to the scenario that was originally selected, in whole or in part. 
     The process described above in steps S. 4  through S. 7  is repeated to determine the best carrier movement scenarios to perform all of the processing operations of the desired pattern, at each of the pattern&#39;s material positions in the x-coordinate direction. 
     Once the best carrier movement scenarios for all of the processing operations in the pattern have been selected, the CPU  72  then separates the respective movements of the individual tool carriers  34  in the y-coordinate direction into pairs of material unit steps in the x-coordinate direction. The CPU  72  “looks ahead” to a fixed number of future material unit steps in the x-coordinate direction to determine whether the future processing operations could be completed more efficiently by performing a portion of the desired pattern on the forward-moving material with limited or no carrier movement in the y-coordinate direction, then “backing up” the material in the x-coordinate direction while repositioning the tool carriers in the y-coordinate direction, and moving the material forward again in the x-coordinate direction to perform another portion of the pattern on the forward-moving material, until the desired processing pattern has been fully completed. As described above, the conveyor unit  30  may move the material backward in the x-coordinate direction through the processing unit  32  while material continues to uncoil from the uncoiler assembly  16 , and any excess material accumulates in the loop located in the slack region  24 . This feature can improve processing efficiency by minimizing overall carrier movement, and by repositioning carriers while the material is “backing up” through the processing unit  32 . 
     In steps S. 10  through S. 16 , the CPU  72  determines the amount of material “back up,” if any, that would minimize the tool carrier  34  travel in the y-coordinate direction required to perform the programmed processing pattern by calculating the combined tool carrier  34  travel in the y-coordinate direction for a series of material unit step iterations in the x-coordinate direction, up to a pre-set maximum allowable number of “back up” material unit steps. The maximum number of “back up” material unit steps is generally defined by the length and depth of the slack region  24 , which determines how much material may be backed up into the loop during operations. To set a baseline datum, the CPU  72  first calculates the amount of carrier travel in the y-coordinate direction required to perform the processing operations in the desired pattern without using any “back up,” and stores this value in memory. The CPU  72  then calculates the total amount of carrier travel in the y-coordinate direction for a series of iterations of “back up” material unit steps in the x-coordinate direction, up to the maximum allowable number of such steps, and stores these in memory. After the iteration for the maximum allowable number of material unit steps has been calculated and stored in memory, the CPU  72  selects a sequence using the amount of “back up” corresponding to the iteration with the least total carrier travel in the y-coordinate direction. If each of the iterations causes either an increase or no change in the total amount of carrier travel, the baseline datum with no “back up” in the x-coordinate direction is selected to process the sheet material. 
     Finally, in step S. 18 , the CPU  72  considers whether the most efficient sequence determined by the iterative process outlined above would cause the tool carriers  34  to collide while completing the processing operation. If a collision would occur, the CPU  72  alters the processing sequence in step S. 19  by directing the tool carriers  34  to clear one another, and may pause or reverse the material in the x-coordinate direction as necessary to permit the processing sequence to be completed. Once the best carrier movement scenario and processing sequence have been selected, the material is processed. 
     As may be recognized by those or ordinary skill in the pertinent art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present invention without departing from its scope as defined in the appended claims. For example, the coil processor may process any of numerous different types of sheet-like material that are currently known, or that later become known, such as different types of metal, plastic, laminates, or other types of materials. The coil processor may utilize different tools for cutting, punching, stamping, bending and/or other operations. Further, the coil processor may be operated using either the tool carriage, the rotating tool carriage, or both. Additionally, more components can be added to those described herein, and some of the described components may be combined into single components, for example, a combination conveyor unit and straightener unit may be used. Moreover, the onboard software in the control unit may be updated or replaced with improved software by methods that are currently known, or that later become known, to those of ordinary skill in the pertinent art, in order to improve the efficiency of operation or for any other reason. Accordingly, this detailed description of currently preferred embodiments is to be taken in an illustrative as opposed to limiting sense.