Can production tool and method of controlling can weight, cost and size

Abstract

The present invention teaches a method of measuring and grinding tools in can / cylindrical can body production that allows for reduced production downtime, reduced costs and the ability to predict tool wear, the method allows for more accurate inventory of tool stock by tracking individual tools in use and providing advanced diagnostics for the tool room. This includes not only out of specification alerts from QA but also predictive alerts on the cans produced per tool, in-spec can weight and wall thickness, information on tool size used in production, tools in inventory, tools removed from inventory and other inventory balancing information. The present invention further teaches a set of equations for distinguishing grinding priority to maintain optimal tool inventory levels.

Description

[0001] Copyright Notice

[0002] Portions of the disclosure of this patent document contain material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever pursuant to 37 CFR 1.71(d).

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims priority to U.S. non-provisional patent application No. 16 / 407,759, filed May 9, 2019; the contents of which are incorporated herein in their entirety.

[0005] Inventor

[0006] Michael Callahan

[0007] Kevin Gillister

[0008] Calvis Jonaraj

[0009] Richard Lord Technical Field

[0010] The present invention relates generally to canmaking tools, and more particularly to dies and punches for canmaking machinery, and more particularly to canmaking machines and associated tooling kits and procedures for reducing can costs, controlling the weight and size of cans produced, reducing spoilage, reducing metal, and making manufacturing more reliable and less prone to downtime during regrinding of punches and dies or changing tooling kits during the canmaking process.

[0011] Statement Regarding Federally Funded Research

[0012] This invention was not made under contract to an agency of the United States Government or any instrumentality of the United States Government. Background Art

[0013] The modern method of making aluminum cans or other cylindrical can bodies utilizes a "bodymaker." A bodymaker is a device that converts a cup into a can by repeatedly punching the cup, except for the flanges, coating, etc., which are already completed. The lid is a separate entity / device and is sewn onto the can.

[0014] Can design starts with can specifications and requirements, dome and cylinder strength, wall thickness (both thin and thick). These will determine incoming metal thickness, cup design, and can requirements for punch and dome tooling design along with can maker die reduction.

[0015] Figure 9 (Prior Art) is an older canmaker design. Figure 9The reference numerals on the figures may be ignored as not relevant to this patent application. A can making machine must form the aluminum can body through a series of steps called drawing and ironing steps. These steps (re-drawing and repeated ironing) require a series of punches and dies for each step, which are performed at high speeds, but are required to produce cans with very precise weight / thickness of can wall material. Too little material and the can will not meet specifications / requirements, and too much material will result in material waste, thus increasing the cost of the can. For a given size can, the weight of the can is largely determined by the wall thickness, not by small deviations in the can diameter. Deviations of less than 0.0001 inches can cause problems, so the measurement accuracy used in the tooling is very high.

[0016] These steps can be summarized as follows.

[0017] 1) The initial punch will usually reshape the cup, but the redrawn can will not yet be the proper size and shape.

[0018] 2) The can is then stamped through several (eg three) ironing dies, each of which gradually reduces the wall thickness.

[0019] 3) The cans go through a QA step where they check for wall thickness, can weight, regularity, etc. This step is very important as a small variation in can wall thickness can add $10 or $20 to the cost of 100,000 cans (a fairly small number) simply because excess aluminum was consumed during the ironing process.

[0020] This process sounds simple, but there are actually additional factors that lead to a cascade of potential problems. In particular, dies and punches wear. As they wear, they change dimensions, causing cans produced on different dies and punches to deviate from the acceptable weight. This deviation is noticed during QA, at which point production is typically stopped while the worn die or punch is replaced with a new one, or both. Typically, through use, wear, and resharpening, the inside diameter (ID) of the die increases, while the outside diameter (OD) of the punch decreases.

[0021] Even worse, in mass production, a die set takes about 2 days (or less than 1 million cans). Given that a full set consists of one punch and three or four dies, if they wear out at random and unrelated intervals, the canmaker will have to be shut down for replacement five times as often.

[0022] However, a correctly matched "tool set" of die and punch is actually necessary because the dies are actually related in size. Figure 3 As shown, a set of punches and dies must be very closely matched to each other with minimal variation from one die to the next. Remember that variations of 0.0001 inches can be problematic, which in turn means that the tool set must be an ordered sequence of sizes.Figure 3 As shown by the hypothetical example in FIG. 8, for a 12 ounce container, there can be a punch with an outer diameter of 2.6030 inches, then a redraw die with an inner diameter of 2.6258 inches, then ironing dies of 2.6196, 2.6149, and 2.6090 inches. The problem is that if the redraw die inner diameter starts to wear up and has to be replaced, a die of exactly the same size has to be replaced. If the exact replacement is not identical, the entire punch and die sequence cannot be used for production and must be replaced entirely.

[0023] Down time results in money loss, increased metal usage, and cost of producing cans or can bodies. Unnecessary tool changeover results in money loss and loss of productivity. In addition, cans become too thin to pass inspection, and cans become too thick also cost money. One estimate is that $0.10 to $0.20 is wasted for every thousand cans due to improper thickness. Since production lines produce millions of cans per day, and most facilities have multiple production lines running, this money adds up quickly.

[0024] Since a typical die is around $100, it is preferable to send the die / punch to the production facility tool shop for regrinding. Even then, only about six uses are allowed for a given die, and it introduces another layer of sizing complexity. In particular, the die can only be ground up in size, so the other dies in the same tool set must also be ground up to match at the end of the production line. Returning to the previous example, if the redraw die is ground to a new, larger diameter of 0.0002 inches, then the rest of the die set must also be ground larger. This will result in a slightly larger diameter of the can / cylindrical can body, but still with the desired wall thickness at the end of production.

[0025] Figure 8A simulation of a prior art production die regrinding process is shown in FIG. 8. This process 802 is generally similar to the process used in the can production industry, but, since various facilities tend to keep their exact operations proprietary, it is labeled as a "simulation" of the prior art. This is not a flowchart, but rather a chart showing the flow of tools through the tool room, inventory, stock to be ground, and the production line. In particular, the stock to be ground 806 includes the number of old (or new) dies and punches available for regrinding that are located on the tool room 804 shelves. Obviously, it is desirable to grind only the minimum amount of a given die that is needed to re-install it into the ordered sequence in a given tool set, so the tool room can allow a certain amount of stock to be ground 806 to accumulate, to allow greater flexibility in maintaining matched sets. The mechanic takes the tools selected from the stock to be ground 806 to the grinder 810. The tools are actually re-ground to the required dimensions at the grinder 810. The mechanic estimates the above dimensions primarily from industry experience and experience at the particular production facility. The tool room staff then dimension checks 812 the dies / punches and marks the dies with the exact dimensions (down to thousandths of an inch or less), so that the exact dimensions are known immediately when the punch / die is located in inventory 814. When a tool change is needed, a selection 816 is made from inventory 814, and the tool flows into production 818. Finally, at some point in time the produced cans are measured (flow to quality assurance 820), the tool wear on a given canning machine causes the cans to deviate, triggering an alarm 832 from QA to production. The production line is (possibly) shut down, and new tools or new tool sets are installed in the canning machine.

[0026] The tool / set used (in this case, possibly a set of four dies and one punch, or one die, or other odd number, e.g., one die and four punches, assuming that it is possible to remove one die and four punches at the same time) then flows back to the stock to be ground 806 at step 826.

[0027] In the past, the handling of this procedure required an experienced mechanic in the tool shop to make temporary judgments hour by hour. Generally, the tool room staff needed to recall (if they knew) the dimensions of the tool set that was being used on the production line (or more likely, on one of several production lines running simultaneously), then the tool room staff would look directly at the dies on the inventory shelves, and guess the dimensions that were likely to wear out and need to be replaced in a timely manner. Since it would take the tool room some time (hours) to regrind the dies, there was no economic possibility of "on the fly" performance. It was better to have the appropriate tools ready, rather than do it on demand, and the mechanic simply carried the inventory and did the best he / she could based on experience.

[0028] One very specific item of feedback is known: QA measurements of can weight and wall thickness. (See row 832 near the bottom of the chart, back from QA to production). This information is often collected and when the weight or thickness (both are obviously related) exceeds a limit, the line workers are told that they need to make a change to the given line. However, when a die / punch changes and the replacement part disappears from inventory, the tool room finds this out.

[0029] Instead, it is preferred to implement a process so that the tool room workers can proactively know how much production has been done with any given die, and the exact tool size that was in production at the time, and receive QA alerts of out-of-spec cans immediately, and even information about the weight and wall thickness of cans being produced that are still within spec.

[0030] It is also preferred to implement a process to allow the tool room to know what size of skimmable stock is available, what size is most likely needed for current production, and to allow the tool room workers to balance this against known inventory levels, allowing stock balancing. SUMMARY

[0031] GENERAL ABSTRACT

[0032] This application is directed to improvements in can bodymakers and associated tooling, and the implementation of processes through the use of the same, including but not limited to: reduced downtime for tool change, reduced damage, improved metal usage (excess metal will be trimmed and sold as scrap, and not put back into cans if not needed), reduced tool set-up / changeover time by having tool sets ready. Additionally, the process can also be used to predict tool wear so that tools are changed before out-of-spec situations occur.

[0033] This invention teaches a process for measuring and grinding tooling in can / cylindrical can body production. The process allows for more accurate inventory of tooling by tracking each tool in use and providing advanced diagnostics to the tool room. This includes out-of-spec alerts from QA and predictive alerts about the cans produced by each tool, in-spec can weight and wall thickness, tool size information used in production, tools in inventory, tools taken from inventory, and other stock balancing information. The invention further teaches several equations for prioritizing grinding to maintain optimal tool inventory levels for improved productivity.

[0034] The present invention teaches that the work of selecting tools and transferring them to production can be informed by many factors, including the ongoing, possibly even real-time results of the can weight and can wall thickness found by the QA department (as well as the IDs that the QA receives that indicate which specific bodymaker the can came from). This provides a proactive measure of which dies or punches can be deviating from optimal (due to wear) before the product actually differs from the required specifications (which is before the out-of-spec alert). Another "feedback" item is the tool production data, which can also be used in tool selection. Additionally, when a given tool is removed from inventory or added to inventory, this helps to provide raw material balancing information to the production team and tool room as they participate in tool selection.

[0035] The present invention also teaches, in another embodiment, that the work of grinding tools in the tool room can be performed more advantageously if a grinding schedule is created. In this way, the tool room staff can operate based on numerical criteria when deciding which tools to remove from the stock to be ground, grind, and return to tool inventory. In one aspect, the tools removed from the production machinery and returned to the stock to be ground can be accompanied by information about which exact tools they are and what the further grinding scheduler can know about the tools used thereafter. However, the available inventory level of ground, ready, tool stock provides a greater advantage of the present invention. By using a simple equation (presented here), the mechanics of the tool room can objectively determine the priority of the work they plan to do based on at least the following factors: the actual number of tools of a given size in the tool inventory, the preferred maximum and minimum values in the inventory, the number of tools of a given size used in production, from which five additional values can be determined: the amount short, the potential amount short, the amount needed to be ground, the priority level of that particular grind, and the priority number.

[0036] CLAIM SUMMARY

[0037] Thus, in addition to those discussed above, another aspect, advantage, object, and embodiment of the present invention provides an improved method of producing cylindrical can bodies on a production line having a bodymaker, a tool shop, and a quality assurance station, the improved method comprising the steps of:

[0038] providing a stock to be ground, a tool inventory, and a tool selection station in the tool shop,

[0039] providing a first set of tools on the bodymaker, the first set of tools comprising a first plurality of tools, the first plurality of tools comprising a first tool having a first size;

[0040] the tool inventory comprising a second plurality of tools not in use on the bodymaker;

[0041] re-drawing and ironing a plurality of cylindrical cans using the first tool set, the production line notifying the tool shop of the number of the plurality of cylindrical cans produced using the first tool;

[0042] the quality assurance station measuring a can wall thickness of a first one of the plurality of cylindrical cans and comparing it to a preset threshold, notifying the tool selection station of the measured can wall thickness, and if the can wall thickness of the first one of the plurality of cylindrical cans exceeds the preset threshold, notifying both the production line and the tool shop, while at the same time the production line returning the first tool of the first tool set to the stock to be ground and replacing the first tool with a second tool taken from the tool inventory, the second tool having the first size;

[0043] re-grinding the first tool.

[0044] Thus, in addition to those discussed above, another aspect, advantage, object and embodiment of the present invention provides an improved method of producing cylindrical cans on a production line having a can body maker, a tool shop and a quality assurance station, the improved method comprising the steps of:

[0045] providing in the tool shop a stock to be ground, a grinding scheduling station and a tool inventory;

[0046] providing on the can body maker a first tool set, the first tool set comprising a first plurality of tools, the first plurality of tools including a first tool having a first size;

[0047] the tool inventory comprising a second plurality of tools not used on the can body maker;

[0048] re-drawing and ironing a plurality of cylindrical cans using the first tool set, the production line notifying the tool shop of the number of the plurality of cylindrical cans produced using the first tool and notifying the grinding scheduling station of a set of sizes of the first tool set used on the can body maker;

[0049] the quality assurance station measuring a can wall thickness of a first one of the plurality of cylindrical cans and comparing it to a preset threshold, and if the can wall thickness of the first one of the plurality of cylindrical cans exceeds the preset threshold, notifying both the production line and the tool shop, while at the same time the production line returning the first tool of the first tool set to the stock to be ground and replacing the first tool with a second tool taken from the tool inventory, the second tool having the first size;

[0050] the tool inventory notifying the grinding scheduling station of the number of tools having the first size in the tool inventory;

[0051] prioritize a task of resharpening the first tool according to a number of tools in the tool inventory having the first size, a number of the plurality of cylindrical shells produced using the first tool, and the set of sizes of the first tool set;

[0052] resharpen the first tool when the first tool has the highest priority in a resharpening schedule.

[0053] Accordingly, in addition to those discussed above, another aspect, advantage, object, and embodiment of the present invention provides an improved method of producing cylindrical shells on a production line having a can bodymaker, a tool shop, and a quality assurance station, the improved method comprising the steps of:

[0054] providing in the tool shop a stock of tools to be sharpened, a sharpening scheduling station, a tool inventory, and a tool selection station,

[0055] providing on the can bodymaker a first tool set comprising a first plurality of tools, the first plurality of tools comprising a first tool having a first size;

[0056] the tool inventory comprising a second plurality of tools not in use on the can bodymaker;

[0057] redrawing and ironing a plurality of cylindrical shells using the first tool set, the production line informing the tool shop of a number of the plurality of cylindrical shells produced using the first tool and informing the sharpening scheduling station of a set of sizes of the first tool set in use on the can bodymaker;

[0058] the quality assurance station measuring a can wall thickness of a first one of the plurality of cylindrical shells and comparing it to a preset threshold, informing the tool selection station of the measured can wall thickness, and if the can wall thickness of the first one of the plurality of cylindrical shells exceeds the preset threshold, informing both the production line and the tool shop, while the production line returns the first tool of the first tool set to the stock of tools to be sharpened and replaces the first tool with a second tool taken from the tool inventory, the second tool having the first size;

[0059] the tool inventory informing the sharpening scheduling station of a number of tools in the tool inventory having the first size;

[0060] prioritizing a task of resharpening the first tool according to a number of tools in the tool inventory having the first size, a number of the plurality of cylindrical shells produced using the first tool, and the set of sizes of the first tool set;

[0061] regrinding the first tool when the priority of the first tool is the highest priority in the regrind schedule.

[0062] Thus, in addition to those discussed above, another aspect, advantage, object and embodiment of the present invention provides a method for regrinding cylindrical can body manufacturing tools having a diameter in a production facility having a quality assurance station, the tools including punches and dies for can making, the method including the steps of:

[0063] a) providing a tool shop with a grinder, a tool inventory including a first plurality of tools ready for use in the production facility, each tool in the tool inventory having an associated diameter, a stock of tools to be ground including a second plurality of tools returned from the production facility, each tool in the stock of tools to be ground having an associated diameter, there being a plurality of associated diameters of tools;

[0064] b) setting a minimum tool quantity M for a first associated diameter ^ ;

[0065] c) setting a maximum tool quantity Mv for the first associated diameter;

[0066] d) setting a product diameter threshold;

[0067] e) measuring a first cylindrical can body produced in the production facility using a first tool, and if the diameter of the first cylindrical can body exceeds the product diameter threshold, replacing the first tool used in production with a second tool taken from the tool inventory, the first tool and the second tool having the first associated diameter;

[0068] f) returning the first tool to the stock of tools to be ground;

[0069] g) subtracting the number A of tools in the tool inventory having the first associated diameter from M ^ , thereby arriving at a value for the deficiency D;

[0070] h) subtracting the number A of tools in the tool inventory having the first associated diameter from Mv, thereby arriving at a value for the amount G q to be ground,

[0071] I) counting the number P q of tools having the first associated diameter used in production, and subtracting the number A of tools in the tool inventory having the first associated diameter from P q , thereby arriving at a value for the potential deficiency D p ;

[0072] j) regrinding the first tool when the potential deficiency D pgreater than zero, assigning a first priority to the first relevant diameter;

[0073] k) when the potential undersize D p less than 1 and the undersize D is greater than zero, assigning a second priority to the first relevant diameter;

[0074] L) when the potential undersize D p less than 1 and the undersize D is less than 1, assigning a third priority to the first relevant diameter;

[0075] m) repeating steps b) through L) for each member of the plurality of relevant diameters until each relevant diameter has been assigned respective values of A, M ^ , Mv, P q , D, G q , and D p ;

[0076] n) comparing the potential undersize D p for each member of the plurality of relevant diameters assigned the first priority and ranking each member from high to low by potential undersize D p , the highest receiving a priority number of 1, the second highest receiving a priority number of 2, until each member of the plurality of relevant diameters assigned the first priority is assigned a priority number;

[0077] O) continuing to assign priority numbers in the same numerical sequence without restarting by comparing the undersize D for each member of the plurality of relevant diameters assigned the second priority and ranking each member from high to low by undersize D;

[0078] p) continuing to assign priority numbers in the same numerical sequence without restarting by comparing the relevant diameter for each member of the plurality of relevant diameters assigned the third priority and ranking each member by diameter;

[0079] q) selecting a selected tool to be reground from the stock to be ground, the selected tool to be reground having a relevant diameter that received the highest priority number;

[0080] r) reginding the selected tool to be reground;

[0081] s) removing the selected tool to be reground from the stock to be ground and adding it to the tool inventory; and

[0082] t) repeating steps g) through s). BRIEF DESCRIPTION OF DRAWINGS

[0083] Figure 1is a block diagram of a first embodiment of the present invention showing a hypothetical tool set consisting of four dies and one punch.

[0084] Figure 2 is an elevation view of a cylindrical can body in different stages of production in a can body maker.

[0085] Figure 3 is a table showing a pair of hypothetical tool sets, both designed to produce cans or containers of about 12 ounces in diameter of about 2.600 inches, resulting in a wall thickness of about 0.0060 inches thick.

[0086] Figure 4 is a flow chart showing four major areas and several sub-areas of a production facility, with emphasis on the tool room, and showing movement of tools through different parts of the facility (as well as alerts and information about tools). This chart shows a first embodiment of the present invention with tool selection and grinding schedules.

[0087] Figure 5 is a process chart showing a production facility, with emphasis on the tool room, and showing movement of tools through different parts of the facility in a second embodiment using tool selection.

[0088] Figure 6 is a process chart showing a production facility, with emphasis on the tool room, and showing movement of tools through different parts of the facility in a third embodiment using planned grinding schedules.

[0089] Figure 7 is a table showing grinding priority differentiation based on various factors listed in the equations taught herein.

[0090] Figure 8 is a simulated example of prior art processes used for tool handling and regrinding in an existing production facility. This chart does not represent any specific known process used by this facility.

[0091] Figure 9 is a prior art can body maker patented in the 1970s.

[0092] List of Reference Numbers

[0093] Figure 1

[0094] Tool Set 100

[0095] Redraw Die 102

[0096] Flattening Die #1 104

[0097] Flattening Die #2 106

[0098] flattening die #3 108

[0099] punch 110

[0100] Figure 2

[0101] can / cylinder body 202a, 202b, 202c, 202d

[0102] Figure 4

[0103] tool use / grind / QA process 402

[0104] tool room 404

[0105] stock to be ground 406

[0106] grind schedule 408

[0107] grinder 410

[0108] dimension check 412

[0109] inventory 414

[0110] tool selection 416

[0111] production line 418

[0112] quality assurance 420

[0113] management 424

[0114] tools and tool data back to tool job 426

[0115] out-of-spec alert sent directly to tool job 428

[0116] predictive alert / can per tool 430

[0117] out-of-spec alert 432

[0118] tool production level 434

[0119] stock balance level 436

[0120] tool size in production 438

[0121] can weight / wall thickness measurement 440

[0122] tool out-of-inventory alert 442

[0123] available inventory level 444

[0124] Figure 5

[0125] Tool usage / grinding / QA process 502

[0126] Tool room 504

[0127] Material to be ground 506

[0128] Grinding 510

[0129] Dimensional check 512

[0130] Inventory 514

[0131] Tool selection 516

[0132] Production line 518

[0133] Quality assurance 520

[0134] Management 524

[0135] Tool and tool data back to tool job 526

[0136] Out-of-spec alert sent directly to tool job 528

[0137] Predictive alert / tank per tool 530

[0138] Out-of-spec alert 532

[0139] Tool production level 534

[0140] Material balance level 536

[0141] Tank weight / wall thickness measurements 540

[0142] Tool out-of-inventory alert 542

[0143] Figure 6

[0144] Tool usage / grinding / QA process 602

[0145] Tool room 604

[0146] Material to be ground 606

[0147] Grinding schedule 608

[0148] Grinder 610

[0149] Dimensional check 612

[0150] Inventory 614

[0151] Production line 618

[0152] Quality assurance 620

[0153] Management 624

[0154] Tool and tool data back to tooling industry 626

[0155] Out-of-spec alerts sent directly to tooling job 628

[0156] Predictive alerts per tool's tank 630

[0157] Out-of-spec alerts 632

[0158] Tool size in production 638

[0159] Available inventory level 644

[0160] Figure 7

[0161] Actual inventory A

[0162] Minimum M ^

[0163] Maximum Mv

[0164] Production quantity P q

[0165] Deficit D

[0166] Grinding amount G q

[0167] Potential deficit D p

[0168] Figure 8 - Simulation of the prior art

[0169] Tool usage / grinding / QA process 802

[0170] Tool room 804

[0171] Grinding stock 806

[0172] Grinder 810

[0173] Size check 812

[0174] Inventory 814

[0175] Tool selection 816

[0176] Production line 818

[0177] Quality assurance 820

[0178] Management 824

[0179] Tool return to tooling job 826

[0180] Out-of-spec alert 832 DETAILED DESCRIPTION

[0181] Glossary

[0182] As used herein, the term "grind stock" refers to the quantity of worn tools and new tools available for grinding, and also generally refers to the area of the tool shop where tools are stored.

[0183] The term "size inspection" refers to ensuring that the re-ground tool is the exact size required for a given tool set, and marking the new exact size of the tool. This results in the "associated diameter" of the tool: knowing the diameter of the tool is critical for correct production. Since tools come in various sizes, there are in fact "multiple associated diameters" in most tool sets, for example, Figure 3 or Figure 7 different diameters as shown.

[0184] As used herein, the term "tool" refers to at least one die or punch used for producing cylindrical can bodies such as cans.

[0185] The term "tool set" refers to a set of dies / punches having very close associated sizes (e.g. Figure 3 as shown in

[0186] The term "tool inventory" or "inventory" or "available inventory level" refers to the tools on hand, re-ground and resized and ready to be put into production as needed, and more generally refers to the area of the tool shop where tools are stored ready for production.

[0187] The terms "tool shop", "production" (or "production line"), QA or "quality assurance", and management refer to the four main areas of the production facility involving tool selection, grinding, cylindrical can body production, etc.

[0188] The terms "can" and "cylindrical body" can be used interchangeably, but for the purposes of this application, the term cylindrical body includes cans, but is not limited to cans, so not all cylindrical bodies are cans, and thus the present invention can be applied to more types of production than just cans. Many consumer products are sold in cylindrical bodies other than cans, such as aluminum bottles and jars for cosmetics, and the like.

[0189] The term "tool production level" refers to the size and quantity of each size of tool used in production, for example, "punch #16543, diameter 3.1005, has run 1,234,567 cycles (or cans produced, strokes, etc.) since last regrind, punch #08765, diameter 3.1004, has run 456,789 cycles since last regrind,...", as this information is sent to the tool selector of the tool shop. In addition, "tool sizes in production" can refer to the sizes of tools that are in the can-making machine at any particular moment, which becomes a notification sent to the grinding scheduler of the tool shop.

[0190] The term "out of spec alarm" refers to a notification from the QA department to the production facility that a can is out of spec (measured by wall thickness, can weight, or other parameter) from the tolerance range / threshold. These notifications can be from QA to production in the prior art, but in the present invention, they can also go directly to the tool shop for use by the tool shop workers. This is somewhat akin to a real alarm, in that emergency action is expected to be taken to return production to acceptable levels.

[0191] On the other hand, the term "predictive alarm" is a notification from the production facility to the tool shop that so many cans have been drawn or ironed on a particular tool. This is useful because the longer a tool is used in production (measured in cans produced) the more likely it is to need replacement soon. The notification can be real-time and updated frequently, or policy can dictate that it occurs at predetermined thresholds.

[0192] Raw material balancing is a fairly delicate use of resources, manifesting itself as an action to send tools of certain sizes to the can body makers based on an excess of those sizes in inventory (i.e., a row of a chart as shown below). Consider the consequences if all the can body makers in a plant used exactly the same size tool: those sizes would run out faster, so the inventory level of those sizes would be lower, while the inventory level of other sizes would be higher. This unbalanced inventory in turn would lead to production interruptions, or the tool shop would be forced to rush to regrind many tools of the same size again. If each can body maker used a slightly different size, with an even distribution of sizes within the range of sizes available, efficiency would be higher. In the real world, can body makers can not be set up to use different sizes that are evenly distributed within the range of sizes available, so raw material balancing addresses this problem by requiring a complete change of the can body maker tool set (when a change is needed anyway) to help balance the raw materials.

[0193] Can weight / wall thickness and similar measures indicate whether a can is within specification (i.e., the can wall is too thick or too thin). Thickness can be measured by the weight of the can. The term “measurements of wall thickness” can include can weight, as can weight depends on the wall thickness of the can and the base material thickness.

[0194] “Tools out of inventory” means tools that are selected to be taken out of inventory and then sent to the production line for use by the can body makers, and in addition, during the process of the invention, these tools are no longer in inventory and thus need to be removed from the inventory records. This is important because it changes the actual quantity in inventory, which can change the level of tool deficiency or potential deficiency, which in turn can raise the priority of regrinding other tools of the same type and size.

[0195] “Available inventory level” has its normal meaning, indicating the number of tools available in inventory and ready to be put into production if needed.

[0196] “Actual” or “A” as used herein means the actual number of tools in inventory.

[0197] “Minimum” or “M ^ ” means the minimum level of tools to keep in inventory per policy.

[0198] “Maximum” or “Mv” means the maximum level of tools to keep in inventory per policy.

[0199] “Quantity in production” or “Pq "Tooling quantity in use" refers to the number of tools of a given size actually used in production.

[0200] "Deficiency" or "D" refers to the lack of tools in inventory and production (P q ) for production and minimum levels, or as a subset of the difference between minimum and actual levels according to Equation 1 below.

[0201] "Grind quantity" or "G q " refers to the difference between the maximum and actual values according to Equation 3 below.

[0202] "Potential deficiency" or "D p " refers to the difference between the production quantity (P q ) and the actual quantity, discussed with reference to Equation 2 in Figure 7 .

[0203] The present production method reduces downtime and lowers production costs by ensuring that the dies and punches are more readily available and more efficiently prioritized, thereby reducing material consumption and increasing the uptime of the plant / line / can bodymaker.

[0204] Glossary ends

[0205] Figure 1 is a block diagram of the first embodiment of the present invention, showing a hypothetical set of tools of four dies and one punch. Figure 1 The set of tools 100 is shown because the sizing of the different tools in the set will necessarily limit the options available to the line / production facility. In particular, the redraw die 102, the ironing die #1 (104), the ironing die #2 (106), and the ironing die #3 (108) must be sequenced in order of size as measured by ID, while the punch 110 (but with different sizes (obviously measured by OD)) must also be matched. This is because the can or other cylindrical can body is not stamped out in a single step operation of the can bodymaker. Rather, Figure 2 is an elevation view of one cylindrical can body at different stages of production by a can bodymaker. The redrawn cup / can / cylindrical can body 202a, 202b, 202c, 202d is worked, stamped, and ironed in several stages, and becomes closer to the desired tolerances for can weight (i.e., material cost) and can thickness (thickness will in part determine weight) with each iteration. These small changes in can wall thickness require small steps in die and punch size.

[0206] Figure 3is a table showing a pair of hypothetical tool sets, both designed to produce cans of about 2.600 inch diameter or 12 ounce containers (about 346 milliliters). It can be immediately seen that the dimensional differences between the different tooling follow an orderly progression without large gaps: the 2.6007 ID in the first tooling becomes 2.6006 in the next tooling, then 2.6005 in the next tooling, and so on.

[0207] The second row is for a second tool set, which is nearly but not quite identical in size.

[0208] Thus, the tooling must be very close in size to the tool set used by the canning machine. This means that the tool set limits the choice of tools that can be substituted when one tool must be replaced due to wear from use, which happens in high volume production over a period of one or two days.

[0209] Figure 8 is a simulation of the prior art process for tool handling and regrinding used in existing production facilities. This figure does not represent any particular proprietary process used by any particular facility. The tool use / grind / QA process 802 can be considered to begin in the tool room 804. Within the tool room 804, a tool is selected from the stock to be ground 806 based on the operator's estimate of the need. The tool goes from the stock to be ground 806 to the grinding station 810 ready to be reintroduced (by regrinding) into the tool inventory for the production line. Immediately after regrinding, measurement and inspection 812 is performed and a label of the exact size is put on the tool so that it is only used for tool sets that fit the correct dimensional order. The tool does not go directly into production unless it is immediately needed to restart production, but rather the tool is generally added to the tool inventory 814 and waits to be selected 816 for production 818.

[0210] Cylindrical can bodies produced by the canning machine using the tool are measured by the tool room personnel 812. Generally, quality assurance initiates the only rigorous measurement and return sequence. When a threshold of can wall thickness or can weight is exceeded, QA 820 notifies 832 production 818 of the problem. At this point production is involved, the worn tool is removed from the canning machine and returned 826 to the stock to be ground 806.

[0211] Management 824 oversees QA information, moves cans, and orders new tool inventory as needed or based on the estimate of the need.

[0212] Figure 4is a flow chart showing the four main areas of a production facility and several sub-areas, with a focus on the tool room, and showing the movement of tools as they pass through different parts of the facility (as well as alerts and information about the tools). This figure shows the first embodiment of the invention, which has a tool selection and grinding schedule, with the goal of providing a more stable flow of dies and punches in the tool inventory, so that it is never necessary to change more tools (changing one tool is faster than changing an entire tool set).

[0213] To do this, the workers in the tool room should have a procedure to guide them in selecting dies for regrinding. Figure 4 This will make it possible to depict more complex tool flows, as well as notifications from one part of the can factory to another.

[0214] The production facility has four main parts: the actual production facility / production line itself, the tool room, the quality assurance station, and management. Note that "station" can refer to a department or one employee, a workroom equipped with a specific tool available, any useful communication or automation equipment (phone, computer), and so on. The goal of the invention is not to reinvent the entire production line, but to add a station / process (the grinding schedule station) and regrind tools in a systematic order, rather than according to the experience of the tool room employees.

[0215] The tool use / grinding / QA process 402 thus operates under the assumption of a tool room 404, a production line 418, and a quality assurance 420.

[0216] The stock to be ground 406 will have multiple tools waiting to be regrinded. However, the order in which the regrinding takes place can cause unnecessary production downtime, carry an unnecessarily large inventory of tools, waste labor costs, and other issues related to optimal production efficiency.

[0217] The grinding schedule 408 will be implemented according to the procedures needed to increase the degree of cooperation between the different stations / departments of the facility, in particular allowing the creation of a grinding schedule based on information from the production line and QA department, as well as prioritizing the planned stock to be ground based on information from the production line and QA department.

[0218] The grinder 410 is the station where the physical grinding of each tool takes place. The mechanics of the grinding station will have access to the grinding schedule, so that they do not have to quickly guess the tool size that is most likely needed.

[0219] The size check 412 simply checks the actual size of each tool coming out of the grinding station and flags the tool with the exact size of the tool, specifically the OD of the punch and the ID of the die. This is mandatory because each tool must be used in a set of other tools with sequential sizes. Thus, each tool has an associated diameter and there are multiple associated diameters in the tools in the stock, in the tools in the stock, in the tools actually used in production (on the can bodymaker), and other multiple associated diameters in the tools actually used in production (on the can bodymaker).

[0220] The stock 414 then receives the tools with the determined sizes and, in contrast to known prior art, the stock of units for a given associated diameter is increased and reported back to the grinder scheduling station, which can reduce the priority level or priority number for that particular size of tool (discussed below with respect to Figure 7 The stock 414 then receives the tools with the determined sizes and, in contrast to known prior art, the stock of units for a given associated diameter is increased and reported back to the grinder scheduling station, which can reduce the priority level or priority number for that particular size of tool (discussed below with respect to

[0221] In the present invention, the tool selection station 416 is a more systematic process than in the prior art because it is informed by information received from the production personnel, as discussed in relation to the subsequent steps in the present invention procedure.

[0222] The production line 418 sends the cylindrical can bodies produced by the can bodymaker using the tools to quality assurance 420. The quality assurance 420 measures the products to verify that they are within the tolerances / thresholds. However, in the present invention, the QA 420 not only alerts the production 418 when a can is out of tolerance (step 432). The management 424 implementing the present invention, the QA 420 also informs the tool selection station 416 of the can weight and wall thickness 440 data, even if the can is not out of threshold and is perfectly acceptable. Furthermore, when the QA 420 alerts the production 418 of a can that is over / under threshold, the QA 420 will also send the same notification 428 to the tool shop 404, a step not found in the prior art.

[0223] Furthermore, the production 418 informs the tool shop 404 of the actual tool sizes (multiple associated tool diameters, and the number of tools for each different diameter) used in production 438, a notification not found in known prior art. Furthermore, the production 418 even provides predictive, forward-looking information to the tool shop 404 in the form of information about the number of cans produced for a given tool (step 430). This innovation is useful because it allows the tool shop 404 to see that a given tool has, for example, drawn over a million cans and is thus more likely to need replacement. The same information is provided to the tool selection station (step 434).

[0224] Tool inventory station 414 provides raw material balancing levels 436 to tool selection station 416, detailing by size which tool sets should be used to maintain a balance of use of various size ranges of different can making machines of the facility. Selection station 416 will inform tool inventory 414 when to remove tools from inventory (step 442), and inventory 414 will in turn inform grinding schedule 408 (444) of available inventory levels.

[0225] The tool is then returned to the tool shop at step 426 to be ground raw material 406, but along with the tool itself is sent data about the tool (this can be considered two separate steps, but is shown as one for clarity of the illustration).

[0226] The invention can also be used in part.

[0227] Figure 5 is a process diagram showing a production facility, focusing on the tool room, and showing movement of tools (and alerts and information about tools) through different parts of the facility in a second embodiment of tool selection in use. Figure 5 More complex tool flow is depicted, as well as notification from one part of the can factory to another, which will make this possible.

[0228] The production facility has four main parts: the actual production facility / production line itself, the tool shop, the quality assurance station, and management. Note that a "station" can refer to a department or one employee, a workroom equipped with a particular tool available, any useful communication or automation equipment (phone, computer), and so on.

[0229] The raw material to be ground 506 will have multiple tools waiting to be re-ground. However, the order of re-grinding can cause unnecessary production downtime, carrying unnecessary large amounts of tool inventory, wasted labor costs, and other issues related to optimal production efficiency.

[0230] Grinder 510 is the station where the physical grinding of each tool takes place.

[0231] Size check 512 is simply a check of the actual size of each tool coming out of the grinding station, and marking the tool with the exact size of the tool, specifically the OD of the punch and the ID of the die. This is mandatory because each tool must be used with a set of other tools that have sequential sizes. It is also unique to the invention that raw material balancing information is reported forward from inventory to tool selection station 516.

[0232] Tool selection station 516 is a more systematic process in the invention than in the prior art, as it is informed by information received from production personnel, as discussed in relation to subsequent steps in the process of the invention.

[0233] The production line 518 sends the cylindrical cans to quality assurance 520. The quality assurance 520 measures the products to verify that they are within the tolerance / threshold. However, in the present invention, the QA 520 does not simply alert the production 518 of the cans when they are out of tolerance (step 532). The management 524 implements the present invention, and the QA 520 also informs the tool selection station 516 of the can weight and wall thickness data 540, even if the cans are not exceeding the threshold and are perfectly acceptable. Additionally, when the QA 520 alerts the production 518 of cans that are exceeding / under the threshold, the QA 520 will also send the same notification 528 to the tool shop 504, which is also an un-discovered step in the prior art.

[0234] Furthermore, the production 518 provides predictive, forward-looking information to the tool shop 504 in the form of information about the number of cans that have been produced with a given tool (step 530). The same information is provided to the tool selection station (step 534).

[0235] The raw material balance level 536 is provided to the tool selection station 516 by the tool inventory station 514. The tool selection station 516 will inform the tool inventory 514 when to take tools out of inventory (step 542).

[0236] The tools are then returned to the tool shop to be ground raw material 506 at step 526, but data about the tools is sent with the tools themselves (this can be considered two separate steps, but is shown as one step for clarity of the illustration).

[0237] On the other hand, Figure 6 is a flowchart showing a production facility, focusing on the tool room 604, and showing the movement of tools 602 through the different parts of the facility (as well as alerts and information about the tools) in a third embodiment. The third embodiment uses a planned grinding schedule 608, and the tool selection is not anything other than moving tools from inventory 614 to production 618.

[0238] The raw material to be ground 606 is prepared for grinding according to the grinding schedule 608, and when the matter reaches the highest priority number, it enters the grinder 610 for regrinding, inspection, dimensioning, association with the dimensions 612, and enters inventory 614. The inventory 614 alerts the schedule 608 of the inventory level 644.

[0239] The production line 618 sends predictive alerts / notifications of cans per tool 630 and the relevant diameter that is currently in production to the scheduling department 608 (638) directly.

[0240] The quality assurance 620 will send out-of-specification alerts to the tool room, the traditional alerts to production (632) and the innovative alerts to the tool room (628), which of course will result in the tools and tool data being returned to the tool job at step 626.

[0241] Importantly, as all stages of production and tooling work in concert, useful parameters can also be invented. In particular,

[0242] Figure 7 is a table showing grinding priorities based on the various factors listed in the equations taught herein. In particular, it is now possible to statistically derive and calculate "deficit", "potential deficit", and "to be ground" based on the information collected from all departments sharing the information listed herein.

[0243] "A" is the actual number of tools in inventory that are ready for production.

[0244] "M ^ " is the minimum level of tools that will be kept in inventory according to policy based on management, production, and tool room, and quality assurance information.

[0245] "Mv" then refers to the maximum number of tools that will be kept in inventory according to the second facility policy.

[0246] Finally, the number of tools in use at any moment in production or "P q " refers to the number of tools of a given size that are actually in use in production.

[0247] Note that each of these numbers is largely independent for each different size of tool (2.6184, 2.6196, etc...), so in effect there are multiple sets of numbers, each set associated with a different diameter of the multiple relevant diameters. And since the tools are distributed in three main places (to be ground stock, tool inventory, and production), in effect there are three sets of numbers for each size and for each location. The grinding schedule personnel will need to keep track of a large set of numbers to compare and determine their priorities.

[0248] New indicators can now be derived.

[0249] "Deficit" or "D" refers to the lack of tools in inventory 414 and production (P q ) to meet production 418 and the minimum level, or as the difference between the minimum and the actual number of tools, according to the following Equation 1.

[0250] Equation 1 D = M ^ -A

[0251] This indicates that when a policy specifies holding a certain minimum level of inventory, but there is not enough inventory to meet the minimum, then there is a deficit, for example, a policy minimum of 3 tools of size 2.6184 (first row of Figure 7 ), but there are actually only 2 tools in inventory, which means that 1 tool is missing.

[0252] However, in practice this has not been found to be the highest priority indicator, requiring additional work.

[0253] In particular, the tool size actually used in production and weighted according to the number of each size used in the production line 418 has been found to be almost critical. This represents the potential deficiency amount or "D p " in recent times and is calculated as the difference between the production number (P q ) and the actual number in the tool inventory 414.

[0254] Equation 2 D p = P q - A

[0255] This high priority indicator is important in the short term and forms the basis of the system, not only numbering the tool sizes in order of priority (see Figure 7 , tool size 2.6182 has a priority number of 1), but also creating priority levels. Thus, the item sizes (relevant diameters) with a positive potential deficiency amount D p belong to the highest priority level, regardless of the size of their deficiency amount D, and all such relevant diameters should be processed first, from the largest D p to the smallest.

[0256] Items that have a deficiency amount D but no D p then become the second priority level, after the items of the first level, the items of the second level being processed in order of D value from the largest to the smallest.

[0257] As a third priority, items can be processed from the largest diameter to the smallest diameter or other rules can be derived and adopted.

[0258] The number of items to be ground is also important. It is assumed that the tool room finds it easiest to repeatedly grind tools of a single size rather than adjusting the grinding machine or the like after each tool to a different size, possibly with multiple tool grindings. In this case, according to Equation 3 below, the "amount to be ground" or "G q " refers to the difference between the maximum number that can be held in the inventory and the actual number in the inventory.

[0259] Equation 3 G q = Mv - A

[0260] On the other hand, in other embodiments, G q may be ignored in favor of updating the grinding schedule after each tool is ground, sent to inventory, returned from production, etc. In such embodiments, the calculation can be done anew after each individual change in tool availability data.

[0261] Part of this process can be automated, or at least partially automated: alarms, information transmission, etc. can be performed by using programmable computers, programmed with non-volatile memory, commanding them to perform part of these tasks, such as an electronic spreadsheet, automatic QA measurements, or others.

[0262] The present disclosure is provided to enable any person skilled in the art to practice the application as claimed by the appended claims. The present disclosure is

[0263] Methods and assemblies are described herein. However, variants of the application can also be obtained using methods and assemblies similar or equivalent to those described herein. The materials, articles, assemblies, methods, and examples are merely illustrative and are not intended to limit.

[0264] While only a few embodiments have been described above in detail, other embodiments are possible, and the inventors intend to encompass those embodiments in the present description. The description describes particular examples to enable he who is skilled in the art to practice the more general concept that can be implemented in another way. The present disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative that can be predictable by a person of ordinary skill in the art.

[0265] The principles of the application have been illustrated and described in exemplary embodiments, it being apparent to those skilled in the art that the examples described are exemplary embodiments and can be modified in arrangement and detail without departing from such principles. The techniques from any example can be incorporated into one or more of any other example. The specification and examples are intended to be illustrative only, the true scope and spirit of the present application being indicated by the appended claims.

Claims

1. A method for regrinding a cylindrical can body manufacturing tool having a diameter, said cylindrical can body manufacturing tool comprising a punch and a die for can making, in a production facility having a quality assurance station, said method allowing for reduced production downtime, reduced costs and the ability to have a predicted tool wear, and reduced production line downtime and production costs, characterized in that, The method comprises the steps of: a) providing a tool shop with a grinder, a tool inventory, a stock of tools to be ground, and a tool selection station, the tool inventory comprising a first plurality of tools ready for use in the production facility, each tool in the tool inventory having an associated diameter, the stock of tools to be ground comprising a second plurality of tools returned from the production facility, each tool in the stock of tools to be ground having an associated diameter, there being a plurality of associated diameters of tools; b) setting a minimum tool quantity M for the first relevant diameter ^ ; c) setting a maximum tool quantity Mv for the first associated diameter; d) setting a product diameter threshold; e) measuring a first cylindrical can body produced in the production facility using a first tool, if the diameter of the first cylindrical can body exceeds the product diameter threshold, replacing the first tool used in production with a second tool taken from the tool inventory, the first tool and the second tool having the first associated diameter; f) returning the first tool to the stock of tools to be ground; g) From M ^ subtracting the number A of tools having the first relevant diameter in the tool inventory from the number A of tools having the first relevant diameter, thereby obtaining the value of the shortage D; h) subtracting the number A of tools having the first relevant diameter from the tool stock from Mv, thereby arriving at the amount G to be ground q the value of I) the number P of tools with said first relevant diameter used in the statistical production q and subtracting from P q the number A of tools with said first relevant diameter in the tool stock, thus obtaining the value of the potential deficit D p . j) when said potential underdose D p a first priority is assigned to said first relevant diameter; k) when said potential underdose D p assigning a second priority to said first relevant diameter when said potential underdose D is less than 1 and said underdose D is greater than zero; L) when said potential insufficient amount D p a third priority is assigned to said first relevant diameter when said potential insufficient amount D is less than 1 and said insufficient amount D is less than 1. m) for each member of the plurality of relevant diameters, repeating steps b) through L) until each relevant diameter has been assigned a respective value of A, M ^ , Mv, P q , D, G q , and D p . n) comparing the potential deficit amount D of each member of the plurality of related diameters assigned the first priority p and assigning a priority number to each member of the plurality of related diameters assigned the first priority according to the potential deficit amount D p ranking each member from high to low, the highest receiving a priority number of 1, the second highest receiving a priority number of 2, until each member of the plurality of related diameters assigned the first priority is assigned a priority number; g) continuing the assignment of priority numbers in the same numerical sequence without restarting by comparing the deficit amounts D of each member of the plurality of associated diameters assigned the second priority, and ordering each member by deficit amount D from high to low; h) continuing the assignment of priority numbers in the same numerical sequence without restarting by comparing the associated diameters of each member of the plurality of associated diameters assigned the third priority, and ordering each member by diameter; i) selecting a selected tool to be reground from the stock of tools to be ground, the selected tool to be reground having an associated diameter that attains the highest priority number; j) regrounding the selected tool to be reground; k) removing the selected tool to be reground from the stock of tools to be ground and adding it to the tool inventory; and l) repeating steps g) through k).

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