This application is a continuation-in-part of United States Patent Application Serial Number 09/620,541, filed on July 22,2000 for"Direct Part Marking of Parts With Encoded Symbology-Method Apparatus and Symbology", assigned to the assignee of the instant application.

BACKGROUND OF THE INVENTION-DESCRIPTION OF THE PRIOR ART Industry utilizes part (article) identification markings to relate parts, components, sub-assemblies, devices, mechanisms, etc. to their respective histories. A wide range of marking methods has been developed for this purpose including means to apply encoded and/or otherwise machine-readable symbols used for automatic data collection. These methods involve the use of attached identification means such as adhesive backed labels and tapes, bands, tags, identification plates, and direct part markings (DPMs), which are applied to or formed by altering a part's surface.

DPM is generally recommended in applications where: 1) traceability is required after the product is separated from its temporary identification, such as marked packaging; 2) the part is too small to be marked with a bar code label or tag, or 3) the part is subjected

to environmental conditions that preclude the use of an attached identification means that will not survive those conditions.

DPM can generally be subdivided into two general categories: intrusive and non- intrusive.

Intrusive marking methods alter a surface by abrasion, cutting, burning, vaporizing, or other destructive means. Intrusive marking methods include methods such as micro-abrasive blast, dot peening, electro-chemical etch, machine engraving, milling, laser etching, engraving, or other similar marking methods.

Non-intrusive markings, also known as additive markings, can be produced as part of the manufacturing process, such as mold and cast or forging, or by adding a layer of media to a surface using methods that have no adverse effects on material properties.

Examples of additive marking would be ink jet, silkscreen, stencil, or other similar marking methods.

While both non-intrusive and intrusive marking methods are widely used in industry, their applications are limited. Non-intrusive markings are not generally used in applications associated with harsh environments. For instance, ink marking would not be used to mark engine components because the high heat experienced by the part during operations would burn off the marking media. Intrusive markings, which were designed to survive harsh environments, are considered to be controlled defects in high stress applications and can degrade material properties beyond a point of acceptability.

Consequently, some intrusive markings, especially those done by some laser marking processes, are generally not used in safety critical applications without appropriate metallurgical testing and engineering approval. Safety critical applications include parts whose failure could result in hazardous conditions. Examples of safety critical

applications are systems related to aircraft propulsion, vehicle control, equipment handling, high pressure, pyrotechnics and nuclear, biological and chemical containment.

The aerospace industry is seeking methods to safely apply machine-readable symbols to parts that can withstand harsh environments. The industry currently utilizes cast and forging techniques to create raised or recessed characters representing part identification numbers (usually part and/or lot traceability). Automated part identification and processes therefore, for the investment casting industry are shown and described, for example, in U. S. SN 09/620,541, Roxby et al, (assigned to the assignee of the instant invention). Reliable apparatus and processes to add machine-readable markings to products produced using sand casting or forging processes were, however, still required.

The raw materials used in a sand cast or forging process start as metal billets.

These billets are often initially identified with human readable characters, which are usually applied using the die and punch marking method. This process involves the placement of a sequential advanced impression stamp or individual dies containing a letter (s) or number (s) near the surface of the billet and then striking it with a hammer with sufficient force to transfer a recessed representation of the identifier to the billet surface.

This part identification number is lost during manufacturing and is sometimes reapplied to the product after casting or forging to link it to the material that it is manufactured from.

Part numbers are typically applied to sand cast or forged products by stamping or machining a representation of the number into the mold. This recessed number is then transferred to the part when the liquid metal is poured (Fig. 3) or beaten into the mold (Fig. 1). However, these methods and apparatuses do not apply to serial numbers because they do not provide a means to quickly change the part identifier in the mold between each part casting or forging operation.

While this manual process has worked well for the industry in the past, the human readable characters cannot be captured by the automated data capture devices being utilized in the automatic identification technology (AIT) tracking systems being adopted by industry. This lack of serialization also prohibits users from being able to relate individual parts to their respective historical records.

Aircraft Transportation Association (ATA) Specification 2000, NASA Standard NASA-STD-6002, and NASA Handbook NASA-HDBK-6003, which have been recently released, require application of machine-readable markings containing unique part identifiers (license tag numbers). Given these new requirements, the aircraft industry has been looking for ways to add Data Matrix type symbols to cast and forged parts.

While many consider that the use of an insert containing a representation of a Data Matrix type symbol placed in a recess in the casting or forging die or mold is the solution, an economical means of producing such inserts has not proved obvious.

Numerous methods for creating the part identification inserts have been tried without success. These include, but are not limited to, chemical milling, dot peen, electron beam (EB), electro-discharge machining (EDM), glass fiber forming, investment casting, ion milling, mechanical drilling, sintering, stencils, thermal spray (combustion, plasma, wire <BR> <BR> arc/arc spray, etc. ) and water jet (WJ). While these processes are somewhat workable, they have not turned out to be practical or cost-effective methods.

Chemical Milling-Chemical milling is the selective etching of material, and requires the material to exhibit metallic properties. Spraying chemical enhancers can speed the chemical etching process to speeds similar to pulsed laser drilling. Chemical milling, however, requires maskants, which can result in under/over cutting and is limited to depth/diameter ratios of two or less. Chemical milling, as the name implies, also

involves the cost of chemicals, chemical handling equipment, and disposal. In addition, the process cannot be used to create data cell shapes that are conducive to optical or sensor reading as defined in this invention.

Dot peening (stamp impression) methods were found to deform the metal inserts in undesirable ways. For instance, material displaced from an impression is likely to be pressed into an adjacent impression or be raised upward to alter the insert surface contour.

Dot peening also lacks the ability to achieve the depths required to form data cells large enough to be read off of rough surfaces or survive many manufacturing or operations environments. These shallow depths are also easily filled with media, making the symbols difficult to locate once covered over.

Electron Beam (EB) -EB has also been used to drill small diameter holes.

However, the small diameter hole quality is affected more severely by small variations in the electron beam parameters and it use is not widespread.

Electro-discharge (EDM) -EDM has been used in the small hole-drilling arena.

EDM is limited to about 125-um diameter holes utilizing state of the art EDM systems.

EDM, when used to drill small holes, is limited to a depth/diameter ratio of approximately 10: 1. Roundness can be maintained to within +/-1.0 micrometer and surface roughness can be as small as 0.1 micrometer. The disadvantages of EDM are the oils used and the cost of disposal. EDM, when applied to small diameter holes, is much slower than larger diameter hole EDM processes because of the need to protect the electrode filaments from damage and off-axis"wander"during the plunge through the material.

Glass Fiber Forming-Glass fibers, in a controlled geometrical pattern or in a totally random pattern, have been used to create holes in"cast-like"components.

Procedurally, the glass fibers are laid out in a mold. The component material is injected

into the mold where it solidifies around the glass matrix. After the mold is removed, the glass fibers are etched out of the component. In most cases, the fibers have soluble cores, surrounding by glass. Therefore the glass"tubes"remain in the component, a potentially limiting factor. The process is a multi-step operation that is considered to be to slow to support serialization.

Ion Milling-Ion milling has been successfully applied to high-precision holes in thin films. It is limited to dept/diameter of five or less. Ion Milling is relatively slow, removing material at a rate of 300 angstroms per minute, to slow to support serialization.

Investment casting, while workable for producing high quality markings in the desired shape, is slow and requires multiple steps to produce. These include the generation of the wax insert, forming of a ceramic outer shell, hearting the shell to remove the wax, pouring of liquid metal into the form, sandblasting to remove the form and cutting to remove the sprue.

Mechanical Drilling-Mechanical engraving, drilling and micro-milling processes, while inexpensive, are slow, and required close monitoring for friction heating and to identify bit wear and breakage. The filings produced by these systems also become a problem and when mixed with the cutting fluids used in these processes, often find there way into adjacent holes and are difficult to remove.

Sintering can be used to produce both raised and recessed patterns, but like investment casting, is slow and require multiple steps to product the inserts.

Stencils-High temperature stencils, cut using mechanical cutters or punch machines, and have been tried in sand cast applications but their use has not been widely accepted because of size limitations, inability to produce desired data cell shapes (reading

difficulties) and product contamination issues, e. g. , ash generated as the stencils burn becomes mixed with molten metal being poured.

Thermal spray processes require the use of stencils to form the marking pattern and can only be used to add materials. Thermal spray marking, like laser engraving, cannot be used to produce data cells shapes that are conducive to reading as further taught in the present innovation.

Water Jet (WJ) -WJ has been primarily used in the cutting applications, but has recently progressed into drilling arena. WJ utilizes a high-pressure water jet with and without abrasive practical additives to abrade the material away from the parent material.

The advantages of WJ include the thermal nature of the abrasion, with little or no heat generated in the material causing material transformation. The disadvantages of WJ include the capital cost, focusing nozzle wear leading to hole variation, and the disposal costs of abrasive laden slurries. WJ also suffers from"skidding"at the hole entrance, that is, over spray at the onset of the hole drilling which produces a gouge along the part surface at the hole entrance.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide new and novel methods, apparatus and identification encoding symbology for direct part marking.

It is another object of this invention to provide new and novel apparatus and methods for casting identification encoded symbology directly into parts.

It is still another object of this invention to provide new and novel identification encoding symbology for casting directly into parts.

It is still another object of this invention to provide new and novel identification encoding symbology for forging directly into parts.

It is yet still another object of this invention to provide new and novel 2D identification encoding symbology for forging directly into parts.

It is yet still another object of this invention to provide new and novel 2D identification encoding symbology for forging directly into parts.

It is a further object of this invention to provide new and novel methods to automate existing manual part identification methods used in conjunction with mold and cast marking processes using laser engineered net shaping (LENS) type solid modeling technology.

It is still a further object of this invention to provide a new and novel software interface between Data Matrix type symbol generation software and laser engineered net shaping (LENS) type technology to provide operators of same with the ability to add two-dimensional information (height or depth dimensions) to encoding symbology.

It is yet still a further object of this invention to provide new and novel configured data elements for Data Matrix type encoding symbols so that illumination thereof provides contrast needed for optimal decoding of the symbols.

It is therefore an object of this invention to provide new and novel methods, apparatus and serialized identification encoding symbology for direct part marking.

It is another object of this invention to provide new and novel apparatus and methods for casting serialized identification encoded symbology directly into parts.

It is still another object of this invention to provide new and novel serialized identification encoding symbology for casting directly into parts.

It is still another object of this invention to provide new and novel serialized identification encoding symbology for forging directly into parts.

It is yet still another object of this invention to provide new and novel 2D serialized identification encoding symbology for forging directly into parts.

It is yet still another object of this invention to provide new and novel 2D serialized identification encoding symbology for forging directly into parts.

It is a further object of this invention to provide new and novel methods to automate existing manual part serialized identification methods used in conjunction with mold and cast marking processes using laser engineered net shaping (LENS) type solid modeling technology.

It is still a further object of this invention to provide a new and novel software interface between Data Matrix type symbol generation software and laser engineered net shaping (LENS) type technology to provide operators of same with the ability to add serialized two-dimensional information (height or depth dimensions) to encoding symbology.

It is yet still a further object of this invention to provide new and novel configured data elements for Data Matrix type serialized encoding symbols so that illumination thereof provides contrast needed for optimal decoding of the symbols.

It is still another object of the present invention to provide new and novel serialized identification markings for application to sand cast and/or forged parts.

It is still another object of the present invention to provide new and novel methods and apparatuses to apply serialized identification markings to sand cast and/or forged parts.

It is still another object of the present invention to provide new and novel serialized identification markings to inserts utilized to sand cast and/or forged parts to apply directly marked serialized identification to sand cast and/or forged parts so made.

It is still another object of this invention to provide new and novel identification markings which are configured to facilitate their respective illumination and subsequent imaging for decoding of the identification markings.

It is yet another object of the present invention to provide new and novel apparatus and methods for applying serialized identification markings to cast and/or forged parts utilizing laser deposition and/or laser engraving.

It is still another object of this invention to provide new and novel apparatuses and methods to automate existing part identification apparatuses and methods used in conjunction with sand cast and/or forging processes using laser deposition to produce identification inserts that can be stamped into sand cast molds or laser engraving to cut recesses directly into sand cast molds or into inserts placed in recesses cut into sand cast and/or forging molds.

It is yet still another object of the present invention is to provide new and novel software interfaces between Data Matrix type symbol generation software and laser markers that provides an operator with the ability to add three-dimensional information (width, height, or depth dimensions) to the representation of part identification marks.

It is yet still another object of the present invention to provide new and novel formatting of Data Matrix type symbol data cell elements to provide contrast needed for successful decoding of such symbol data cell elements.

It is yet still another object of the present invention to provide new and novel configurations for data cell elements of Data Matrix type symbol data cells so that light

is reflected off of features of such data cell elements to provide contrast needed for successful decoding thereof.

It is a further object of the present invention to provide the operator of an identification markings device or system with new and novel features to enter symbol carrier (insert or plug) selection information that includes both shape and size information.

It is still a further object of the invention to provide new and novel features to convert symbol generation information to a format that is recognized by the CAD software used to drive laser symbol identification markers..

Other objects, feature and advantages, of the invention, in its details of construction, arrangement of parts and methods of operation, will be seen from the above and from the following detailed descriptions of the preferred embodiments when considered in conjunction with the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing: FIG. 1 illustrates at positions A, B and C the basic steps used to produce a part in a typical closed impression die forging process; FIG. 2 illustrates a cross section of a part containing identification markings formed during a typical forging operation process; FIG. 3 illustrates liquid metal being poured into a mold to form a part during a typical casting process; FIG. 4 illustrates the cross section of a part containing an identification marking formed during a typical casting process; FIG. 5 illustrates the basic elements of a conventional Data Matrix type symbol;

FIG. 6 illustrates the elements of a completed Data Matrix type symbol; FIG. 7 illustrates a modified Data Matrix type configuration used in conjunction with the present invention; FIG. 8 illustrates the basic components of a laser engineered net shaping (LENS) marking system, incorporating the instant invention; FIG. 9A depicts a preferred embodiment of a raised data cell element formation configuration incorporating the instant invention; FIG. 9B shows a schematic illustration of the formation pattern for the raised data cell element formation of FIG. 9A; FIG. 10 depicts a laser pattern used to build up the raised data cell element formation layers incorporating the instant invention; FIG. 11 illustrates a LENS system being used to generate a Data Matrix type symbol-marking insert incorporating raised data cell element formations of FIG. 9; FIG. 12 illustrates the symbol-marking insert of FIG. 11 as utilized to produce Data Matrix type symbol identification markings incorporating recessed data cell elements, incorporating the instant invention into a part; FIG. 13 illustrates the part identification insert of FIG. 12 being removed from a mold after use in an alternative embodiment of the instant invention; FIG. 14 depicts how light, reflected off of part identification markings, incorporating recessed and surface data cell elements, incorporating the instant invention, provides necessary contrast for decoding of the symbology; FIG. 15 illustrates the part identification markings of the type shown in FIG. 14, that have been covered with a media coating;

FIG. 16 illustrates how recessed data cell element formations incorporating the instant invention are produced using multiple laser engraving passes; FIG. 17 illustrates how a symbol marking insert incorporating recessed data cell formations, incorporating the instant invention is utilized to produce Data Matrix type symbol identification markings incorporating raised data cell elements, incorporating the instant invention onto a part; FIG. 18 depicts how light is reflected off of the part identification markings of FIG. 17 to provide necessary contrast for decoding of same; and FIG. 19 illustrates the part identification markings of the type showing FIG. 18 that have been covered with a media coating.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The integration of laser deposition and laser engraving technology into the sand casting and forging process provides the user community with a means to interject automatic parts identification and data collection into the manufacturing functions with minimal cost or disruption of activities. The preferred identification marking for use with the present invention is the two-dimensional (2-D) matrix symbol.

The 2-D matrix symbol was developed to overcome many of the deficiencies inherent to the first generation (linear bar codes) and second-generation (stacked bar codes) symbol formats. One of the primary changes is the use of square or circular data cells as a carrier of data in lieu of the strips of variable widths used in linear and stacked bar codes. The use of a data cell or element of uniform size and shape makes the matrix type encoded symbology versatile.

In the matrix type code format, black squares or circles (data cells) usually represent a binary"1"and white data cells usually represent a binary"0"; while the opposite or different contrasting colors are also possible. When these binary type encodings are used together in specific sequences, they represent alphanumeric characters.

Equal-sized data cells provide for an easier decoding logic decision process than for bar codes. Upon determining the size and shape of a symbol and its individual data cells, decoding software can quickly reconstruct damaged portions of the code. 2-D matrix type symbols can be produced in square, circular, rectangular or other convenient formats ; and scaled in size to fit into an available marking area.

2-D matrix codes, designed to be applied to any of a variety of articles and products, are known and are described in detail, for example, in U. S. Pat. No. 4,939, 354 (issued Jul. 3,1990 to D. G. Priddy, et al. ). A matrix code can store from one to 2335

alphanumeric characters in any language. An encoding scheme for use with such a symbol has a high degree of redundancy that permits most marking defects to be overcome. 16-bit cyclic redundancy check and data reconstruction capabilities are included in one version; and Reed-Solomon error correction is included in another. Up to 16 symbols can be concatenated. Error correction and checking (ECC) code 200 is preferred.

The new and novel features of the instant invention may be utilized with typical sand casting and/or forging process as hereinafter described.

FIG. 1 at positions A, B and C illustrates the basic steps of a typical impression die forging operation.

Impression die forging pounds or presses metal between two dies 30,32 (called tooling) that contain a precut profile 34 of the desired part 38 (FIG. 1 C). As dies 30,32 are brought together (FIGS. 1B and C) the forging stock 36 undergoes plastic deformation.

A wide range of part geometries can be produced using this method including intricate components with odd shaped features such as ribs, interconnecting webbing, and bosses.

Although many parts are generally symmetrical, others incorporate a wide range of design elements (flanges, protrusions, holes, cavities, pockets, etc. ) that combine to make the forging very non-symmetrical. In addition, parts can be bent or curved in one or several planes, whether they are basically longitudinal, multi-dimensional, or flat. Most engineering metals and alloys can be forged via conventional impression-die processes, among them: aluminum and aluminum alloys; copper and copper alloys; carbon and alloy steels, heat and corrosion resistant steels including stainless; nickel alloys; pure metals, magnesium alloys, reactive and refractory metals; tool steels and certain titanium alloys.

FIG. 2 depicts a cross section view of a part 50 which includes raised data identification elements, features or markings 52; the part and data elements conforming to the shape of a mold 54 after being forged. Mold 54 is formed with an opening 56 configured to correspond to the configuration of part 50 and with recessed identification element formations 58 configured to correspond to the configuration of raised identification elements 52.

Sand molds are usually created using a wood, metal or plastic pattern. The pattern can be a dump box, match plate, or a loose piece. Sand is mixed with a urethane binder in a high-speed mixer. This sand is deposited into a box containing the pattern and all essential gating, risers, and chills for pouring. Part identification numbers may then be pressed into the sand form before the sand mixture sets, which takes only a few minutes.

After the form sets, cores for forming internal passages in the castings are made using the same process. The molds and cores are cleaned and sprayed with a refractory coating.

This coating shields the molten metal from direct contact with the sand and seals the sand grain for a better surface finish. Cores are carefully placed into the molds. The molds are then closed and are ready for pouring.

FIGS. 3 and 4 depict a sand cast mold 60 provided with an opening 62 (FIG. 4) configured to the shape of the part 64 (FIGS. 3 and 4) to be cast. Recessed data identification element formations 66 are formed in mold 60 so that part 64 carries raised identification elements 68. FIG. 4 depicts a cross section view of finished part 64 containing raised part identification elements 68 being removed from sand cast mold 60 containing impression or laser engraved recessed part identification formations 66 produced using the teachings of the instant invention.

While the vertical sections of FIGS. 3 and 4 show only the width and height for part mold 60 and finished part 64, its opening 62 and finished part 64 are three dimensional and include a depth which in plain view may be regular or irregular in peripheral configuration. The respective widths and heights may also be regular or irregular in configuration. In addition, while only a single row of data identification element formations 66 and a selected number of columns of same have been shown for mold 60, and for data identification elements 68 for finished part 64, it should be understood that there are multiple rows of same corresponding to those shown for the symbols and symbology of FIGS. 5, 6 and 7, as will be hereinafter explained in greater detail.

The basic elements of a 2-D matrix type encoded data symbol 70 are illustrated in FIG. 5. Although shown, for example, as a square, such matrix symbols may also be of other regular configurations such as a rectangle. It will usually include a data storage field 80 disposed between either a solid border 82 or a broken border 84 or a combination of same, to facilitate location and decoding of the encoded data. White data cells 86 and black data cells 88 are arranged within data storage field 80, in columns 90 and rows 92 through known conventional methods, to provide encoded data, information and the like.

FIG. 6 illustrates an example of a Data Matrix encoded data symbol 94, which has been placed in the public domain and has been recommended by the American National Standards Institute (ANSI) for use in direct part marking. Symbol 94 includes borders 82 and 84 defining (enclosing) data storage field 80 within which there is an arrangement of black data cells 88 and white data cells 86, arranged in columns 90 and rows 92, of encoded data symbol 94. Generally, symbol 94 is applied to a carrier strip such as a pressure sensitive label or to the product label or its package.

In direct park marking, according to the instant invention, the machine readable- encoded data symbol 100 (FIG. 7), carrying symbology 110, also incorporating the instant invention, is to be formed from the same material as the part. Encoded symbol 100 is not to be generated as an arrangement of black and white data cells carried by a white substrate. The entire data storage field is a single color, the color of the part; and, as such, both the binary 1's 112 and the binary 0's 114 will also be the same color, the color of the part. Quite often the part itself is a shiny and silvery material; but materials of other colors may be required and utilized. A data storage field 116 is still provided and solid borders 118 and/or broken borders 120, or a combination thereof, may still be utilized. However, it should be noted that for symbology 110, of the instant invention, the binary 1 data cells 112 (illustrated in black to better describe the instant invention but which actually will be of the color of the part to be directly marked) are shown to be spaced one from the other by separations 130 to better explain the instant invention. Alternatively, the binary 0 data cells could be the ones illustrated in black and spaced one from the other. The binary 1 and binary 0 data cells will be positioned, for decoding purposes in an imaginary grid arrangement 132, the lines for same appearing in FIG. 7 being shown to facilitate a better understanding of the instant invention. Grid arrangement 132 is also in columns 134a, 134b, 134c to 134n and in rows 136a, 136b, 136c to 136n; the number"n"of such columns and rows comprising part of said symbology 110.

Contrast between the binary 1 cells and binary 0 cells is required in order to decode a symbol. In some available direct part marking systems the cells occupying the binary 0 positions have to have a contrasting color applied to facilitate decoding. This adds cost and provides a situation where subjecting the so marked part to a harsh environment may destroy the contrasting color and thus make decoding impossible. Where dot peening has

been used to directly mark a part contrast between the binary 1's and binary 0's is also required and coating the binary 0's (or 1's) with a contrasting color is still undesirable.

The final dot peened symbol will have recessed cells and cells with an upper surface at the same level as the part surface. The depth of the recessed cells are generally limited because the underlying metal has to be compressed.

Projecting light at an angle to the symbol, such as a dot peened symbol, will, dependent upon the angle at which the illumination impinges upon the symbol, create shadows or glare in the dot-peened recesses. Such shadows or glare will provide a contrast between the observed recessed symbol surfaces and the adjacent unrecessed symbol surfaces. Because the recesses of a dot peened symbol are relatively shallow the shadow so created, or glare, may only cover or reflect from a relatively small area of the recess and decoding may very well be impossible or flawed.

The present invention, by way of example, is hereinafter described in conjunction with otherwise typical casting and forging processes. Integrated into and associated with the casting and forging processes of this invention is the use of laser engineered net shaping (LENS) type solid object technology and processes which provides the user community with a means to interject automatic parts identification and data collection into part manufacturing functions with minimal cost or disruption of activities. While such solid object technology described herein refers to LENS type it should be understood that other types of solid object technology may be utilized as long as such results in encoded symbol marked parts.

Some of the preferred embodiments of this invention utilize the above-described LENS type technologies and processes, as shown with respect to FIGS. 8 thru 10, to fabricate inserts for use in sand casting and forging. Inserts, as shown and described with

respect to FIGS. 11 thru 15, are fabricated with raised data cell element formations to provide finished parts with recessed data cell elements. Other preferred embodiments of this invention utilize laser technologies and processes, as shown and described with respect to FIGS. 16A, B, C and D, provide inserts, as shown and described with respect to FIGS. 17 thru 19, with recessed data cell element formations for finished parts with raised data cell elements. All such inserts are sized and configured to be retained within either sand casting molds or forging dies from which finished parts carrying encoded data symbology are to be fabricated. Such encoded data symbologies may therefore include either recessed data cell elements to represent a binary"1"with the binary"0"comprising the surface of the part disposed within the symbology data storage field 116 (FIG. 7) as part surface data cell elements; or with the recessed data cell elements representing the binary"0"and the part surface data cell elements representing the binary"1".

Alternatively, raised data cell elements may be utilized to represent either the binary"1"or the binary"0"while the part surface data element represents the corresponding respective binary"0"or the binary"1".

A LENS type apparatus, with its software modified to incorporate the instant invention, is utilized for the formation of the data cell elements. Such is accomplished by entering the desired product identification data into a conventionally available data encoded software package to create the instructions required to generate a planar type 2-D Matrix type symbol such as that shown in FIG. 7. This markings portion information is then transferred to an intermediate software package, incorporating the instant invention, where three-dimensional data: for the data cell elements (depth or height); insert dimensional data (area"x"and"y"and thickness and peripheral configuration data; are added into the intermediate software package to create the instructions required to

generate the symbology. The resulting intermediate software package data is then converted to a software format that is recognized by the solid modeling CAD program that creates the data for the LENS process, which is then set into operation to control and direct creation of the data cell elements formations and to locate same on the insert.

It should be understood that while the binary 1 data cells have been shown with peripheral circular cross-sectional configurations that other peripheral cross-sectional configurations (such as, for example, square, rectangular, triangular, etc. ) may also be utilized; and that the binary"0"cells may be formed as described for the binary 1 cells with the corresponding binary 1 cells formed as the above described binary 0 cells. In addition, while the symbol and insert are shown and described as having substantially square configurations they may just as well have other configurations; such as rectangular, circular, triangular, etc or combinations thereof.

FIG. 8 illustrates a laser engineered net shaping (LENS) marker 150 as described in U. S. Patent 5,993, 554 160 projecting a laser beam 152 onto a surface 154 being sprayed with powdered metal 160 to form a molten pool 162 of liquid to form objects 164 of a desired shape. While the LENS process is the preferred marking method for use with respect to the instant invention, other markers and processes as described in U. S. patents 6,027, 699 by Holcom et al; 6,046, 426 by Jeantette et al; 6,066, 285 by Kumer; 6,203, 861 by Kar et al; and 6,238, 614 by Yang et al; may be used. Visible wavelength lasers, utilizing light in the visible light spectrum, are preferred for laser deposition and may include, Ruby-Neodymium doped: Yttrium Lithium Fluoride (Nd: YLF), Neodymium doped: Yttrium Aluminum Garnet (Nd: YAG), Neodymium doped: Yttrium Aluminum Perovskite (Nd: YAP), Neodymium doped: Yttrium Vanadate Orthovanadate (Nd: YV04) and other similar laser types.

Objects 164, of a desired shape, may thus be formed, preferably by LENS marker or system 150 or otherwise as described herein above, to provide raised symbology formations 180 (such as that shown in FIG. 9A) incorporating the instant invention. Each such raised symbology formation 180 may then be utilized, according to the instant invention, to generate or provide either a binary 1 or binary 0 data cell for a Data Matrix type 2-D symbol, such as that shown at 100 (FIG. 7), for direct part marking of cast or forged parts as will be hereinafter described in greater detail. Such raised symbology formations 180 may be arranged in a Data Matrix type symbol arrangement upon an insert which may thereafter either be incorporated into a mold otherwise configured to cast a part, or utilized to forge such part. When the part is thereafter cast or forged, the so arranged raised symbology formations 180 facilitate casting or forging into the part recessed symbology elements that define a Data Matrix type encoded symbol.

Alternatively, the raised symbology formations 180 may be applied directly to an otherwise finished cast or forged part to apply thereto raised symbology elements for a Data Matrix type encoded symbology.

Raised symbology formations 180 may preferably be produced as follows: An operator enters into a factory controller or computer the desired product identification data into an encode software package to create the instructions required to generate a 2-D matrix type symbol 100 (FIG. 7). This information is then transferred to an intermediate software package incorporating the instant invention where three-dimensional data (symbol height) and insert dimensions are added. The resulting data is then converted to a software format that is recognized by the solid modeling CAD program that creates the data for laser deposition marker 150. Mark initiation is then initiated, as by depressing an appropriate key (not shown) to direct the creation of a raised symbology formation 180.

This is accomplished by utilizing high-powered laser beam 152 focused to create molten puddle or pool 162 on a substrate or carrier surface as hereinafter described. Metal powder is then injected into melt pool 162 to increase its volume. Back and forth movements 160 creates a layer of deposited material 164. In a sequential fashion, new layers are then built upon previous layers until the entire object or raised symbology formation 180, represented in the three-dimensional CAD model, is reproduced.

Referring to FIGS. 9A, 9B and 10, a base or first layer 190 for a raised symbology formation 180 is produced by outlining the base area 192 of the formation 180 and then filling said area 192 with lines 192 or smaller circles (not shown) using additional laser passes to fill the entire area 192 with solid material. Subsequent layers 192a, 192b and 192c are then added upon base layer 192 to form a 3-dimenstional raised symbology formation 180. A top part 194 is deposited to top off and finalize each raised symbology formation 180.

It should be noted that raised symbology formations 180 (FIGS. 9A and 9B) have been preferably shown with cone-like external configurations 196. Other external configurations such as pyramid or the like can also be used. The primary consideration is that the top part 194 is smaller in area than the base 190 and that the configuration of sides 198 extend down and out from top part 194 to merge into base 190. It should be further noted that external configuration for surface 200 of sides 198 are preferably shown as irregular and convex-like bumps such as torroids. Other irregular configurations for surface 200 of sides 198 may also be utilized, for reasons to be hereinafter described in greater detail. For that matter, surface 200 for sides 198 may also be smooth as long as they are conical-like, pyramid-like or the like.

To fabricate a part or article with identification data encoded symbology, by way of example of the type, configuration, and content as that shown schematically in plan in FIG. 7, an insert 220 (FIG. 11) is disposed for coaction with LENS marker/system 150.

Insert 220 is configured as hereinabove described and is preferably positioned upon a movable platform 222 so that rows and columns of raised symbology formations 180 may be deposited thereupon as described above with respect to FIGS. 8-10. The respective encoding software will determine which rows and columns will include raised symbology formations 180 and which rows and columns, such as 224 (FIG. 11) are not to receive a raised symbology formation 180. The raised symbology formations 180 will result in recessed data cell elements for the finished cast part as will be hereinafter described and the locations 224 on insert 220 where there is no raised symbology formation 180 will result in a surface symbology element for the finished cast part. The operation of LENS marker/system 150 is as described hereinabove with respect to FIGS. 8-10.

Part identification insert 220, fabricated as described above may thereafter be inserted into a recess 230 (FIG. 12) formed in a mold 232 for subsequent sand casting or forging in otherwise conventional manner. Alternatively data cell formations 180 may be so formed directly into the casting sand of the mold.

Fig. 12 shows a finished part 234 after casting or forging with a row of mixed recessed data cell elements 240 and surface data cell elements 242. It should be understood that the identification encoded symbology thus direct part marked into and onto part 234 will include a predetermined number of rows and columns of recessed data cell elements 240 and surface data cell elements 242 defining the identification encoding symbology for parts 234, and that borders, encoded as hereinabove described, may or may not enclose the data storage field.

A typical forging press 260, utilized to directly mark parts according tot he instant invention is shown by way of example in FIG. 13. A lower die 262 is formed with a part recess 264 configured and shaped to correspond to a part 266 which is to be forged and/or have an encoded identification forged directly thereinto. A marking insert recess 268 is also formed in lower die 262 to receive a marking insert 270 fabricated as described above with respect to FIGS. 8-12. Marking insert 266 will thus have the requisite rows and columns of raised data cell formations 272 and surface positions 274. An upper die 276 is also provided for forging press 260. Alternatively data cell formations for marking cell insert 226 may be formed directly into lower die 262.

Upon the forging of part 266 recessed data cell elements 280 and surface data cell elements 282 will be forged into an onto part 266 in rows and columns to define the encoded identification symbology for part 266. A push rod 284 is provided to facilitate removal of insert 268 and, if required part 266, from die 262.

FIG. 14 schematically shows a part 290, fabricated the same way as similar in appearance and with identification encoded rows and columns of symbology 292 as for parts 234 (FIG. 12) and 266 (FIG. 13). The angular and irregular disposition of the internal surface 294 of recessed data cell elements 296 is such as to reflect illumination impinging upon such surface 294 away from the lens and imaging mechanisms (not shown) of a conventional encoded data symbology reader (not shown) as shown, for example, by lines 298. Alternatively illumination impinging upon surface data cell elements 300 is reflected back to the lens and imaging mechanism of the data symbology reader as shown, by way of example, along lines 302. Thus the requisite contrast between the data cell elements is provided and there is facilitated a successful reading and subsequent decoding of the directly marked identification encoded symbology for the part.

If desired a media coating 310 (FIG. 15) may be applied over the surfaces of recessed data cell elements 310 and surface elements 312 for environmental protection or aesthetic reasons. Ideally the marking depth should be greater than the coating thickness so that the markings can be visibly seen for imaging and decoding using read through paint sensor readers such as thermal, ultrasound and micro-impulse radar.

Fig. 16 illustrates a single, raised data cell formation 340 being cut into a surface using a conventionally available visible wavelength laser 342 configured for engraving.

Laser engraving involves more heat than laser etching and results in the removal of substrate material through vaporization. This technique produces a deep light marking similar to a deep electro-chemical etch marking. The major advantage of this laser marking technique is speed, because it is the quickest laser marking that can be produced.

Although this method appears to be the most vigorous laser marking technique, it generally produces less damage to the substrate than laser etching. The desired recessed data cell formation 340 is obtained by following the same pattern software and three- dimensional CAD model utilized to create the raised data cell formations of the embodiments of FIGS. 8 thru 14.

Each such recessed symbology formation 340 may then be utilized, according to the instant invention, to generate or provide either a binary 1 or binary 0 data cell element for a Data Matrix type 2-D symbol, such as that shown at 100 (FIG. 7), for direct part marking of cast or forged parts as will be hereinafter described in greater detail. Such recessed symbology formations 340 may be arranged in a Data Matrix type symbol arrangement upon an insert which may thereafter either be incorporated into a mold otherwise configured to cast a part, or utilized to forge such part. When the part is thereafter cast or forged, the so arranged recessed symbology formations 340 facilitates

casting or forging into the part raised symbology elements that define a Data Matrix type encoded symbol.

Alternatively, the recessed symbology formations 340 may be applied directly to an otherwise finished cast or forged part to apply thereto recessed symbology elements for a Data Matrix type encoded symbology.

Recessed symbology formations 340 may preferably be produced as follows: An operator enters into a factory controller or computer the desired product identification data into an encoded software package to create the instructions required to generate a 2-D matrix type symbol 100 (FIG. 7). This information is then transferred to an intermediate software package incorporating the instant invention where three-dimensional data (symbol height) and insert dimensions are added. The resulting data is then converted to a software format that is recognized by the modeling CAD program that creates the data for laser 342. Mark initiation is then initiated, as by depressing an appropriate key (not shown) to direct the creation of a recessed symbology formation 340. This is accomplished by utilizing a high-powered laser bean 344 (FIG. 16) focused to create recessed formation 340 of desired configuration. In a sequential fasion, new recesses are then cut into an insert until the entire recessed symbology formation 340, represented in the three-dimensional CAD model, is reproduced.

Referring to FIG. 16 at A shows how a base or first cut 350 for a recessed symbology formation 340 is produced by outlining the base area 352 of the formation 340 and then cutting said area 352 to the desired configuration and depth using additional laser passes to cut the entire area 352. Subsequent cuts 352a, 352b, 352c and 352d are then effected to form a three-dimensional recessed symbology formation 340. A bottom cut 354 finalized each recessed symbology formation 340.

It should be noted that recessed symbology formations 340 (FIG. 16) have been preferably shown with cone-like external configurations 360. Other external configurations such as pyramid or the like can also be used. The primary consideration is that the top part 354 is smaller in area than the base 350 and that the configuration of sides 362 extend down and in from base 350 to bottom cut 354. It should be further noted that external configuration for surface 364 of sides 362 are preferably shown as irregular and concave-like. Other irregular configurations for surface 364 of sides 362 such as torroidal may also be utilized, for reasons to be hereinafter described in greater detail. For that matter, surface 364 for sides 362 may also be smooth as long as they are conical-like, pyramid-like or the like.

To fabricate a part or article with identification data encoded symbology, by way of example of the type, configuration and content as that shown schematically in plan in FIG. 7, an insert 400 (FIG. 17) is disposed for coaction with laser marker/system 342.

Insert 400 is configured as hereinabove described and may preferably be positioned upon a movable platform like that of FIG. 11, so that rows and columns of recessed symbology formations 340 may be formed therein. The respective encoding software will determine which rows and columns will include recessed symbology formations 340 and which rows and columns, are not to receive a recessed symbology formation 340. The recessed symbology formations 340 will result in raised data cell elements for the finished cast part as will be hereinafter described and the locations on the insert where there is no recessed symbology formation 340 will result in a surface symbology element for the finished cast part.

A part identification insert 400, fabricated as described above may thereafter be inserted into a recess 420 (FIG. 17) formed in a mold 422 for subsequent sand casting or forging in otherwise conventional manner.

FIG. 17 shows a finished part 430 after casting or forging with a row of mixed raised data cell elements 432 and surface data cell elements 434. It should be understood that the identification encoded symbology thus direct part marked into and onto part 400 will include a predetermined number of rows and columns of raised data cell elements 432 and surface data cell elements 434 defining the identification encoding symbology for parts 400, and that borders, encoded as hereinabove described, may or may not enclose the data storage field.

Upon the casting or forging of part 400 raised data cell elements 432 and surface data cell elements 434 will be applied directly into and onto part 400 in rows and columns to define the encoded identification symbology for part 400.

FIG. 18 schematically shows a part 500, fabricated the same way as, similar in appearance to, and with identification encoded rows and columns of symbology 502. The angular and irregular disposition of the internal surface 504 of raised data cell elements 506 is such as to reflect illumination impinging upon such surface 504 away from the lens and imaging mechanisms (not shown) of a conventional encoded data symbology reader (not shown) as shown, for example, by lines 508. Alternatively illumination impinging upon surface data cell elements 510 is reflected back to the lens and imaging mechanism of the data symbology reader as shown, by way of example, by lines 512. Thus, the requisite contrast between the data cell elements is provided and there is facilitated a successful reading and subsequent decoding of the directly marked identification encoded symbology for the part.

If desired, a media coating 520 (FIG. 19) may be applied over the surfaces of raised data cell elements 522 and surface elements 524 for environmental protection or aesthetic reasons. Ideally, the marking height should be greater than the coating thickness so that the markings can be visibly seen for imaging and decoding using read through paint sensor readers such as thermal, ultrasound and micro-impulse radar.

It should be noted that by utilizing the above described processes for marking <BR> <BR> articles (parts, etc. ) that such processes, and the resulting identification encoded articles are easily marked with such encoded data cell elements in an automated manner and that such articles may included serialized markings.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiments of the invention, which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications, which do not depart from the spirit of the invention, are intended to be included within the scope of the appended claims.