U.S. patent application number 09/986659 was filed with the patent office on 2002-05-02 for bar code stencil and method of use.
Invention is credited to Cantwell, Jay S..
Application Number | 20020050332 09/986659 |
Document ID | / |
Family ID | 22687276 |
Filed Date | 2002-05-02 |
United States Patent
Application |
20020050332 |
Kind Code |
A1 |
Cantwell, Jay S. |
May 2, 2002 |
Bar code stencil and method of use
Abstract
A bar code identification stencil for uniquely identifying a
plurality of articles. The stencil includes a carrier strip, which
carries an identification code or symbology. The identification
code or symbology is formed of a plurality of spaced apart data
cells, or data cells, which are used to form a machine readable bar
code. The stencil will be made of materials compatible to the
manufacturing processes, which make the articles to be marked, and
compatible to the materials out of which the articles to be marked
are made. The stencil is scalable in size and shape, as are the
data cells, or data cells, scalable in size and shape--all as
required by the specifications of the data symbology to be directly
marked on the part, or article. The bar code is unique for each of
the plurality of articles to be identified.
Inventors: |
Cantwell, Jay S.;
(Bridgeton, MO) |
Correspondence
Address: |
BANNER & WITCOFF
1001 G STREET N W
SUITE 1100
WASHINGTON
DC
20001
US
|
Family ID: |
22687276 |
Appl. No.: |
09/986659 |
Filed: |
November 9, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09986659 |
Nov 9, 2001 |
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09839159 |
Apr 23, 2001 |
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09839159 |
Apr 23, 2001 |
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09187017 |
Nov 6, 1998 |
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6220333 |
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Current U.S.
Class: |
164/98 |
Current CPC
Class: |
B29C 39/10 20130101;
G06K 19/06028 20130101; B29C 33/424 20130101; B29C 39/026 20130101;
G06K 2019/06271 20130101; B22D 17/2245 20130101; B29C 2037/80
20130101; B29C 45/372 20130101; B22D 46/00 20130101; G06K 1/12
20130101 |
Class at
Publication: |
164/98 |
International
Class: |
B22D 019/00 |
Claims
I claim:
1. A bar code identification stencil for uniquely identifying a
plurality of articles, said stencil comprising: a carrier strip for
carrying an identification code; and an identification code carried
by said carrier strip, said identification code being formed of a
plurality of spaced a part data cells of generally elongated shape
formed in said carrier strip, said data cells forming a machine
readable bar code which is unique for each of said plurality of
articles to be identified.
2. A bar code identification stencil according to claim 1, wherein
said carrier strip is generally rectangular in shape.
3. A bar code identification stencil according to claim 1, wherein
said carrier strip is generally uniform in thickness.
4. A bar code identification stencil according to claim 1, wherein
each of said data cells are generally parallel to each other.
5. A bar code identification stencil according to claim 4, wherein
each of said data cells are generally of the same length.
6. A bar code identification stencil according to claim 1, wherein
each of said data cells is formed by a depression in said carrier
strip.
7. A bar code identification stencil according to claim 1, wherein
each of said data cells is formed by a cutout in said carrier
strip.
8. A bar code identification stencil according to claim 7, wherein
each of said cutouts extends fully through said carrier strip.
9. A bar code identification stencil according to claim 1, wherein
said carrier strip is generally flexible in order to conform to the
shape of an article being identified by said identification
stencil.
10. A bar code identification stencil according to claim 1, wherein
said carrier strip is made from a fiber reinforced material with a
bind agent for containing said fiber reinforced material.
11. A bar code identification stencil according to claim 1, wherein
said carrier strip is made from a material which can withstand a
temperature of at least 3,500 degrees F. without being damaged to
the point that said identification stencil is no longer useful for
its intended purpose.
12. A bar code identification stencil according to claim 1, wherein
said carrier strip is made from a material which can withstand a
pressure of at least 5,000 PSI without being damaged to the point
that said identification stencil is no longer useful for its
intended purpose.
13. A bar code identification stencil according to claim 1, wherein
said carrier strip is made from a material which can withstand a
vacuum of at least 30 inches of mercury without being damaged to
the point that said identification stencil is no longer useful for
its intended purpose.
14. A bar code identification stencil according to claim 1, wherein
said identification code is formed of a plurality of identification
code elements and wherein said carrier strip includes a plurality
of identification code element locations, said data cells being
formed at selected ones of said element locations.
15. A bar code identification stencil according to claim 14,
wherein the presence or absence of a said marker at a said element
location forms a unique identification code for said identification
stencil.
16. A bar code identification stencil according to claim 1 further
comprising an attachment element for attaching said identification
stencil to an article to be identified by said identification
stencil.
17. A bar code identification stencil according to claim 16,
wherein said attachment element includes an adhesive tape.
18. A bar code identification stencil according to claim 16,
wherein said attachment element includes a double-back adhesive
tape with a first side of said adhesive tape adhered to said
carrier strip and a second side of said adhesive tape adhered to a
release liner.
19. A bar code identification stencil according to claim 1, wherein
said carrier strip is adapted to be attached to an interior surface
of a cast used to cast the article to be identified by said
identification stencil using an attachment material.
20. A bar code identification stencil according to claim 19,
wherein said carrier strip further includes a barrier layer for
preventing said attachment material from coming into contact with
said carrier strip.
21. A bar code identification stencil according to claim 1, wherein
said carrier strip is adapted to be attached to an interior surface
of a mold used to mold the article to be identified by said
identification stencil using an attachment material.
22. A bar code identification stencil according to claim 6, wherein
said carrier strip includes runner and gate depressions through
which a molding material can be supplied to fill said marker
depressions during an injection molding process.
23. A bar code identification stencil according to claim 22,
wherein said gate depression is formed along one edge of said
carrier strip.
24. A bar code identification stencil according to claim 23,
wherein said gate depression is connected to said runner
depression.
25. A bar code identification stencil according to claim 24,
wherein said runner depression is connected to each of said marker
depressions.
26. A bar code identification stencil according to claim 25,
wherein at least one end of said marker depressions terminate in an
opening at an edge of said carrier strip.
27. A bar code identification stencil according to claim 6, wherein
said carrier strip further includes human readable symbols which
correspond to said identification code.
28. A bar code identification stencil according to claim 27,
wherein said human readable symbols are formed as depressions in
said carrier strip.
29. A bar code identification stencil according to claim 28,
wherein said runner depression is connected to each of said symbol
depressions.
30. A bar code identification stencil according to claim 29,
wherein an edge of each of said symbol depressions forms an opening
at an edge of said carrier strip.
31. A method for uniquely identifying a plurality of cast articles
using a machine readable bar code number integrally cast into said
article during the casting process, said method comprising the
steps of: providing a bar code identification stencil having a
carrier strip which carries an identification code, said
identification code being formed of a plurality of spaced a part
voids and being unique for each of said plurality of articles to be
identified; attaching said stencil to an interior surface of the
cast used to cast said articles; filling said cast with casting
material to cast said article and to fill said voids to thereby
form said bar code number; and using a different said stencil for
each of said plurality articles to be cast.
32. The method of claim 31, wherein said carrier strip includes an
attachment element for attaching said identification stencil to
said interior surface of said cast.
33. The method of claim 32, wherein said carrier strip is adapted
to be attached to said interior surface of said cast using an
attachment material.
34. The method of claim 33, wherein said carrier strip further
includes a barrier layer for preventing said attachment material
from coming into contact with said carrier strip.
35. The method of claim 31, wherein each of said voids are formed
by a depression in said carrier strip.
36. The method of claim 31, wherein each of said voids is formed by
a cutout in said carrier strip.
37. The method of claim 36, wherein each of said cutouts extends
fully through said carrier strip.
38. The method of claim 31, wherein said carrier strip is generally
flexible in order to conform to the shape of the interior surface
of said cast to which said stencil is attached.
39. The method of claim 31, wherein said carrier strip is made from
mineral fiber.
40. The method of claim 31, wherein said carrier strip is made from
wood pulp.
41. The method of claim 31, wherein said carrier strip is made from
mica.
42. The method of claim 31, wherein said carrier strip is made from
a material which can withstand a temperature of at least 3,000
degrees F. without being damaged to the point that said
identification stencil is no longer useful for its intended
purpose.
43. The method of claim 31, wherein said carrier strip is made from
a material which can withstand a pressure of at least 1500 PSI
without being damaged to the point that said identification stencil
is no longer useful for its intended purpose.
44. The method of claim 31, wherein said identification code is
formed of a plurality of identification code elements and wherein
said carrier strip includes a plurality of identification code
element locations, said voids being formed at selected ones of said
element locations.
45. The method of claim 44, wherein the presence or absence of a
said void at a said element location forms a unique identification
code for said identification stencil.
46. The method of claim 31, wherein said carrier strip further
includes an attachment element for attaching said identification
stencil to said interior surface of said cast.
47. The method of claim 31, wherein said carrier strip is adapted
to be attached to said interior surface of said cast using an
attachment material.
48. The method of claim 47, wherein said carrier strip further
includes a barrier layer for preventing said attachment material
from coming into contact with said carrier strip.
49. A method for uniquely identifying a plurality of molded
articles using a machine readable bar code number integrally molded
into said article during the molding process, said method
comprising the steps of: providing a bar code identification
stencil having a carrier strip which carries an identification
code, said identification code being formed of a plurality of
spaced a part voids and being unique for each of said plurality of
articles to be identified; attaching said stencil to an interior
surface of the mold used to mold said articles; filling said mold
with molding material to mold said article and to fill said voids
to thereby form said bar code number; and using a different said
stencil for each of said plurality of articles to be molded.
50. The method of claim 49, wherein each of said voids extends
through said carrier strip.
51. The method of claim 49, wherein each of said voids are formed
by a depression in said carrier strip.
52. The method of claim 49, wherein each of said voids is formed by
a cutout in said carrier strip.
53. The method of claim 52, wherein each of said cutouts extends
fully through said carrier strip.
54. The method of claim 49, wherein said carrier strip is generally
flexible in order to conform to the shape of the interior surface
of said cast to which said stencil is attached.
55. The method of claim 49, wherein said carrier strip is made from
mineral fiber.
56. The method of claim 49, wherein said carrier strip is made from
wood pulp.
57. The method of claim 49, wherein said carrier strip is made from
mica.
58. The method of claim 49, wherein said carrier strip is made from
a material which can withstand a temperature of at least 3,000
degrees F. without being damaged to the point that said
identification stencil is no longer useful for its intended
purpose.
59. The method of claim 49, wherein said carrier strip is made from
a material which can withstand a pressure of at least 1500 PSI
without being damaged to the point that said identification stencil
is no longer useful for its intended purpose.
60. The method of claim 49, wherein said identification code is
formed of a plurality of identification code elements and wherein
said carrier strip includes a plurality of identification code
element locations, said voids being formed at selected ones of said
element locations.
61. The method of claim 60, wherein the presence or absence of a
said void at a said element location forms a unique identification
code for said identification stencil.
62. The method of claim 49, wherein said carrier strip further
includes an attachment element for attaching said identification
stencil to said interior surface of said cast.
63. The method of claim 49, wherein said carrier strip is adapted
to be attached to said interior surface of said cast using an
attachment material.
64. The method of claim 63, wherein said carrier strip further
includes a barrier layer for preventing said attachment material
from coming into contact with said carrier strip.
65. A method for uniquely identifying a plurality of articles made
from a material hardening process using a machine readable bar code
number integrally formed in said articles during the hardening
process, said method comprising the steps of: providing a bar code
identification stencil having a carrier strip which carries an
identification code, said identification code being formed of a
plurality of spaced a part voids and being unique for each of said
plurality of articles to be identified; attaching said stencil to
an interior surface of the cast used to cast said articles; filling
said cast with casting material to cast said article and to fill
said voids to thereby form said bar code number; and using a
different said stencil for each of said plurality articles to be
cast.
66. A method for uniquely identifying a plurality of cast articles
using a machine readable bar code number integrally cast into said
article during the casting process, said method comprising the
steps of: providing a bar code identification stencil having a
carrier strip which carries an identification code, said
identification code being formed of a plurality of spaced a part
voids and being unique for each of said plurality of articles to be
identified; attaching said stencil to an interior surface of the
cast used to cast said articles; filling said cast with casting
material to cast said article and to fill said voids to thereby
form said bar code number; and using a different said stencil for
each of said plurality articles to be cast.
67. A method for uniquely identifying a plurality of articles using
a machine readable bar code number, said method comprising the
steps of: providing a bar code identification stencil having a
carrier strip which carries an identification code, said
identification code being formed of a plurality of spaced a part
voids and being unique for each of said plurality of articles to be
identified; attaching said stencil to a plurality of said articles;
filling said voids to thereby form said bar code number; and using
a different said stencil for each of said plurality of articles to
be identified.
68. The method of claim 67, wherein each of said voids extends
through said carrier strip.
69. The method of claim 67, wherein each of said voids are formed
by a depression in said carrier strip.
70. The method of claim 67, wherein each of said voids is formed by
a cutout in said carrier strip.
71. The method of claim 70, wherein each of said cutouts extends
fully through said carrier strip.
72. The method of claim 67, wherein said carrier strip is generally
flexible in order to conform to the shape of the interior surface
of said cast to which said stencil is attached.
73. The method of claim 67, wherein said carrier strip is made from
mineral fiber.
74. The method of claim 67, wherein said carrier strip is made from
wood pulp.
75. The method of claim 67, wherein said carrier strip is made from
mica.
76. The method of claim 67, wherein said carrier strip is made from
a material which can withstand a temperature of at least 3,000
degrees F. without being damaged to the point that said
identification stencil is no longer useful for its intended
purpose.
77. The method of claim 67, wherein said carrier strip is made from
a material which can withstand a pressure of at least 1500 PSI
without being damaged to the point that said identification stencil
is no longer useful for its intended purpose.
78. The method of claim 67, wherein said identification code is
formed of a plurality of identification code elements and wherein
said carrier strip includes a plurality of identification code
element locations, said voids being formed at selected ones of said
element locations.
79. The method of claim 78, wherein the presence or absence of a
said void at a said element location forms a unique identification
code for said identification stencil.
80. The method of claim 67, wherein said carrier strip further
includes an attachment element for attaching said identification
stencil to said articles.
81. The method of claim 67, wherein each of said voids are filled
by spraying a heated metal into said voids.
82. The method of claim 67, wherein each of said voids are filled
by spraying paint into said voids.
83. The method of claim 67, wherein each of said voids are filled
by spraying rubber into said voids.
84. The method of claim 67, wherein each of said voids are filled
by spraying a material into said voids.
Description
REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of application Ser. No. 09/839,159
filed Apr. 23, 2001 which is a division of application Ser. No.
08/187,017 filed Nov. 6, 1998 and which is now U.S. Pat. No.
6,220,333.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of identification
bar codes, readers, and scanners, and more particularly, is
directed to a bar code stencil and method of using such a stencil
to integrally embed, bond, attach, mold, or adhere a bar code into
or onto an article during its manufacture, remanufacture,
rebuilding, or revitalization. The stencil may also be used in a
postproduction or aftermarket refit identification procedure for
bar code marking of articles.
[0003] The development of modern bar codes began in the 1940s in
response to the food industry's need for a reliable and economical
system for inventory control and for automatically reading product
information at grocery store checkouts. The first patent to issue
on such a system is believed to be U.S. Pat. No. 2,612,994 entitled
Classifying Apparatus and Method and which issued on Oct. 7,
1952.
[0004] Although the coding system used in the '994 patent relied on
a series of concentric circles to encode the identification
information, the original coding approach developed by the
inventors was a series of narrow and wide vertical lines much like
present day bar code systems. Early implementations of the
concentric circle approach proved unreliable however, as the
circles were difficult to print without smearing. Smeared circles
introduced reading errors when scanned and thus were unacceptable.
The use of vertical bars eliminated the smearing problem and
associated scanning errors.
[0005] Since the adoption of the Universal Product Code (UPC) in
1973, bar codes have proliferated to virtually all areas of article
and product identification. Bar codes are now widely recognized as
an economical and reliable identification system.
[0006] Over the years, a number of different versions of the UPC
bar code have been developed. Version A is one of the most popular
and is illustrated in FIG. 1. The Version A format includes a
plurality of spaced vertical bars 1 which form the bar code and a
plurality of human readable digits which correspond to the bar
code, i.e., "0 25528 43507 3" as indicted by reference number
2.
[0007] As shown in FIG. 1, the code is divided into 12 digits, with
the first digit 3 being usually a "0". The next five digits 4 are
assigned to the product manufacturer by the Uniform Code Council
and thus serve to identify the manufacturer. Accordingly, all of
the bar codes for the same manufacturer will have these same five
digits. The next five digits 5 represent the item identification
code given to a particular product by the manufacture. Thus, 99,999
products can be uniquely identified. The final twelfth digit 6 is a
check digit which is used by the bar code scanner to confirm the
accuracy of the scan.
[0008] Each of the human readable digits is encoded into the code
using a two-part binary coding system as indicated in the table
below:
1 Code Key Digit Left Right Value Binary Code Binary Code 0 0001101
1110010 1 0011001 1100110 2 0010011 1101100 3 0111101 1000010 4
0100011 1011100 5 0110001 1001110 6 0101111 1010000 7 0111011
1000100 8 0110111 1001000 9 0001011 1110100
[0009] Each A1" in the key code is represented by a black bar 7 as
illustrated in FIG. 1 and each A0" in the key code is represented
by a white line or space 8. There is a center code of four lines
(binary digits 01010) which bisect the bar code. On the left side
of the bar code, the Left Binary Code digits from the above table
are used and on the right side of the bar code, the Right Binary
Code digits from the table are used. This mirror image coding
technique allows the scanner to read the number code in either
direction. Start and stop codes are used by the scanner to set the
width of the binary digits within the bar code symbol. The scanner
also uses the check digit to calculate a check sum as is know in
the art. If the correct check sum is not calculated, the bar code
read is rejected.
[0010] FIG. 2 is a further illustration of a typical UPC bar code
with its constituent parts labeled.
[0011] As a testament to the popularity of bar code use, the UPC
bar code is scheduled to be phased out by the year 2005 because its
12-digit length will no longer be sufficient to handle the demand
for bar codes. In its place, the United States is expected to adopt
a version of the European Article Numbering (EAN) system. The EAN
bar code system has thirteen digits and can thus accommodate
substantially more product identifications than the UPC.
[0012] The traditional printed bar code system continues to serve
its original purpose of grocery store inventory control and check
out very well. Bar codes formed of conventional two-dimensional
printed bars work well where the article to be labeled is not
subject to a harsh environment and the bar code label is not likely
to be rubbed off or smeared over so that it cannot be read.
[0013] The food industry serves as an ideal environment for
conventional bar codes. Bar codes used for food labeling are
unlikely to be subjected to harsh environments due to the inherent
need to prevent adulteration and damage to the food package. Thus,
the bar code label is not likely to become damaged or
unreadable.
[0014] The bar code system has in some respects however, become the
victim of its own success. Today, attempts are being made to use
bar codes in many environments in which a conventional printed
two-dimensional bar code, such as the one used for food products,
cannot be used. One such environment is the tire manufacturing
industry.
[0015] U.S. Pat. No. 5,160,383 assigned to Goodyear Tire &
Rubber discloses one example of the use of a bar code labeling
technique in the tire industry. According to the patent, it is
important that a tire label be highly durable so that it may still
be read after many years of tire service and multiple retreadings.
The patent also notes that serial numbers can be molded into tire
sidewalls but that doing so is labor intensive and costly. Thus,
Goodyear sought to improve upon conventional tire labeling systems
by attaching an identification label to the rubber inter lining of
an uncured tire. The label is made of two materials which are
co-curable with the rubber of the tire. The tire is then cured
using a conventional curing process which results in the label
becoming permanently affixed to the inside of the tire.
[0016] Goodyear also is the assignee of U.S. Pat. No. 4,625,101
which discloses a method of molding a bar code configuration onto
the sidewall of a tire. The bar code configuration has a plurality
of sloped reflective surfaces which allow more flexibility in
locating the bar code scanner without adversely effecting the
accuracy of the scan. A bar code plate mold insert is used to mold
the bar code configuration into the sidewall of the tire during the
vulcanization process.
[0017] Another technique for labeling a tire is disclosed in U.S.
Pat. No. 4,941,522 assigned to the Yokohama Rubber Company. The
Yokohama approach involves an improved bar code plate mold insert
which is also used to mold a bar code into a side wall of the tire
during the vulcanization process. The improved plate is said to
solve the problem of deterioration of the tire's resistance to
weather in the area of the molded bar code.
[0018] The instant invention differs from the above-cited patents
in many respects, the chief of which being both the uniqueness of
each stencil and the disposability of the stencil. That is, the
instant invention requires that each stencil be made with a code
unique to the part being marked. Because harsh environment marks
are typically placed on durable goods, i.e., car parts, aerospace
parts, heavy equipment parts, oil pipes, etc., the market and
regulatory need is for traceability throughout the useful life of
the part and the piece of equipment, machine, or item of which the
marked part is assembled into. In essence, the marks made possible
by the instant invention will allow databases to be developed which
follow the marked part from the date of marking to the end of the
useful life. It is contemplated that the marks made possible by the
instant invention will play an important role in facilitating
databases of safety critical parts in many, many industries,
including aerospace, automotive, energy, and the like.
[0019] Like the tire manufacturing industry, bar code labels also
have great utility in other harsh environments as well. For
example, domestic metal casters cast and ship millions of tons of
product each year. An effective way to identify each product for
tracking and inventory control purposes is to label it with a bar
code. Because casts usually are subjected to a post casting process
to finish and shape them to their final form, a conventional
printed bar code label is often difficult to apply to a casting
surface and is also subject to being rubbed off or covered over
during the subsequent finishing process. Moreover, a printed bar
code label is likely to deteriorate over time, well before the end
of the life of the cast itself, making the bar code difficult or
impossible to read.
[0020] Ideally, an identification bar code will be embedded into
the article during the manufacturing process. Doing so, avoids the
possibility of misidentification, i.e., the wrong bar code being
applied, in a subsequent labeling step.
[0021] In order to improve the durability and readability of bar
codes in harsh environments such as casting, a three-dimensional
bar code construction was developed. An end view of a portion of
such a bar code is illustrated in FIG. 3. Each bar has a width 30
and a height 31. The distinguishing feature of this type of bar
code is its height 31. The bar code is scanned by a
three-dimensional bar code reader which detects the presence or
absence of a bar based on its height rather than its contrast as a
conventional two dimensional bar code reader does. Thus, a three
dimensional bar code can be read when no color contrast is
available. Contrast, for reading purposes, is supplied by the
profile of the data cell relative to the surrounding surface, and
the direction of the lighting of the reading device. Light beams
are sometimes recaptured, or directed in such a way to cast
`shadows,` or are directed to reflect away from the reading device.
Three dimensional bar code readers are known in the art, and
include the readers formerly manufactured by the Sensis Corporation
(laser illuminated), and more readily available optical readers
manufactured by such companies as Cognex Corporation, DVT, Inc.,
Robotic Vision Systems, Inc., and others. Most of the reading
systems now capable of deciphering three dimensional, or Bumpy, bar
codes evolved out of vision inspection systems, and have made their
appearance in the marketplace relatively recently.
[0022] Three dimensional bar codes have proved to be a much better
choice in some situations as they will not easily rub off, smear,
peel, or vanish because bonding strengths, in essence, equate to a
direct part marking system, or in case of molding processes, are,
in fact, simply contours in the part itself.
[0023] Three-dimensional bar codes can be painted over or the
article on which they are placed can be subjected to various
treatment processes without the readability of the bar code being
adversely affected. Three-dimensional bar codes are also useful
where a traditional printed bar code label will not adhere to the
surface of the article to be labeled.
[0024] The use of bar codes during manufacture for work-in-process
tracking, inventory control, work piece routing, etc., has become a
valuable tool. Embedding, or molding, the bar code into the article
during its manufacture is the most expedient and cost effective
identification system. However, due to the harsh environments in
which many manufacturing processes occur embedding or molding a bar
code into a manufactured article can present many challenges. These
challenges involve overcoming the ill effects caused by the very
high temperatures, abrasive and corrosive treatments and processes,
and pressures that are present in, e.g., cast and molding
processes, forging, machining, and other manufacturing or
remanufacturing processes. In addition to OEM manufacturing there
are millions and millions of parts, often safety critical, that are
currently in use which need traceability, and in some instances,
require traceability by reason of governmental regulation. Thus,
there is a need in the art for a bar code stencil which can be
easily and reliably used for embedding, molding, or otherwise
adhering bar codes by means of a direct part marking process into
or onto articles during their manufacture, remanufacture,
maintenance, or normal use.
SUMMARY OF THE INVENTION
[0025] Accordingly, it is an objective of the present invention to
obviate the above-noted shortcomings and disadvantages of present
methods of marking an article with a bar code.
[0026] It is a further objective of the present invention to
provide an improved method of bar code marking which is more
reliable and cost effective than conventional methods.
[0027] It is a still further objective of the present invention to
provide an improved method of bar code marking which is economical
to implement and simple in operation.
[0028] It is a still further objective of the present invention to
provide an improved method of bar code marking which can be used in
harsh environments.
[0029] It is another objective of the present invention to provide
an improved method of bar code marking which can be used to embed a
bar code into a metal cast article during the casting process.
[0030] It is a further objective of the present invention to
provide an improved method of bar code marking which can be used to
embed a bar code into a molded article, of whatever material made,
during the molding process.
[0031] It is a another objective of the present invention to
provide an improved method of bar code marking which can be used to
bar code an article in the field, or during a maintenance,
rebuilding, or revitalization process by means of chemical or
mechanical bonding including, but not limited to epoxies, electrode
or chemical etch processes, and thermal sprays.
[0032] It is still another objective of the present invention to
provide a bar code stencil which allows all of the above noted
objectives to achieved.
[0033] The bar code stencil of the present invention, allows the
embedding of a permanently formed bar code into a cast metal or
molded part at the point of manufacture. The stencils can have
sequentially numbered bar codes that are placed directly into a
mold cavity. Once in the cavity, the mold is closed and filled as
normal with the desired material. The result is a bar code that is
literally molded or cast onto or into the surface of the finished
article out of the same material as the article.
[0034] In thermal spray application of bar codes, the bar code
stencil of the present invention allows the embedding and/or
bonding of a permanently formed bar code onto and/or into a part by
means of extremely high temperatures and mechanical bonding of
selected materials into the part being marked. Thermal spray
processes are well established and used in many industries. Thermal
spray processes were invented nearly a hundred years ago, and have
been extensively used in industry for nearly seventy years. Just as
the bar code stencil of the present invention allows a normal
casting or molding process to become a highly durable and
dependable direct part marking process, so the bar code stencil of
the present invention allows this immensely durable coating
technology to be used as an immensely durable direct part marking
process for the application of bar code symbologies. In thermal
spraying, metal wires, metal powders, ceramics, or other materials
are melted at a combustion point and then sprayed onto a prepared
surface by means of compressed air. While the combustion point will
be thousands of degrees, the surface of the part being sprayed will
rarely exceed 350 degrees during the spraying process, well below
temperatures that would adversely affect the structural integrity
of the material out of which the part is made. As the hot, molten
spray hits the part surface the disparity of the temperatures and
the force of the spray causes a mechanical bond, which will be many
thousands of pounds per square inch. Using this system with the
present invention creates a highly durable and dependable bar code.
Electrode coating and chemical etch processes can be similarly
adapted to become marking systems through the use of the stencil of
the present invention.
[0035] The bars which form the bar code take on a raised,
three-dimensional form that has all the strength and visual
characteristics of the parent article material and can be read
through grease and grim unlike the bars on a printed label.
[0036] Several variations of the stencil can be provided for
different article manufacturing, remanufacturing, or maintenance
processes. Variations in the stencils are primarily based on the
temperature and pressures that a particular process requires when
generating an article. For example, casting a bar code into the
side of an iron engine block requires a stencil capable of
withstanding in excess of 3,000 degrees F. with very little
pressure. A stencil for use in molding a bar code integral to an
injection-molded article, however, requires a material capable of
5,000 degrees F. and 3,500 PSI.
[0037] The stencil of the present invention can be sequentially, or
uniquely, encoded with any number of digits in any x-dimension and
with most of the bar code symbologies in use today, including the
so-called 2D codes such as data matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The novel features of the present invention are set out with
particularity in the appended claims, but the invention will be
understood more fully and clearly from the following detailed
description of the invention as set forth in the accompanying
drawings in which:
[0039] FIGS. 1 and 2 are illustrations of a UPC bar code;
[0040] FIG. 3 is an illustration of a three dimensional bar
code;
[0041] FIG. 4 is an illustration of a bar code stencil in
accordance with the present invention;
[0042] FIGS. 5-13 are various bar code cross sections;
[0043] FIG. 14 is a side view of a bar code stencil in accordance
with the present invention illustrating the use of a double back
adhesive tape;
[0044] FIG. 15 is a side view of a bar code stencil in accordance
with the present invention illustrating the use of an over
laminate;
[0045] FIG. 16 is a top view of a bar code stencil in accordance
with the present invention which is adapted for use in a plastic
mold;
[0046] FIG. 17 is a side view of a bar code stencil in accordance
with the present invention illustrating its use in a recessed
cavity of a sand or metal mold;
[0047] FIG. 18 is a side view of a bar code stencil in accordance
with the present invention illustrating its use on the surface of a
sand or metal mold;
[0048] FIG. 19 is a side view of a bar code stencil in accordance
with the present invention illustrating its use with a chemical
bond; and
[0049] FIG. 20 is a side view of a bar code stencil in accordance
with the present invention illustrating its use with a spray
material.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0050] A preferred embodiment of the present invention will now be
described with further reference to accompanying drawings.
[0051] FIG. 4 illustrates one embodiment of a bar code stencil
according to the present invention. The stencil includes a carrier
strip 40 with an area 41 in which pluralities of bar code marker
locations 42 are provided along carrier strip 40. Bar code marker
locations 42 may also be referred to as "data cells" locations.
When the bar code is formed on the work piece, the data cell
locations form data cells or bar code makers which convey the bar
information. The stencil may be used with virtually any bar code
symbology without departing from the spirit and objectives of the
invention.
[0052] Carrier strip 40 will generally be a square or rectangular
shape, depending on the symbology used and the shape and size of
the part to be marked, and its size will likewise depend on the
symbology used and the shape and size of the part to be marked as
well as the manufacturing processes to which the part will be
subjected after marking. Sizes may range from as much as a 12
square inch area to stencils that are only fractions of an inch in
total area.
[0053] Carrier strip 40 may be made from a number of materials
known in the prior art, including materials which have fiber
reinforcement with a binding agent to contain the fiber
reinforcement. Other materials will include, but not be limited to,
vinyls, polyesters, plastics, waxes, and the like. In essence, the
stencil of the subject invention will often be made of materials
used or compatible with the manufacturing processes and materials
used in the making of the part to be marked. Likewise, given that
the stencil is inserted in a casting or molding process, the
stencil may serve other purposes, such as the formation of a void
or part feature, in addition to the forming of a bar code
symbology. For example, in a casting process the data symbology may
be punched, routed, or drilled into a core insert material, and the
core insert material will then be placed into the cast mold. While
the core insert's purpose is to form a feature of the casting, it
may also serve to form and place the bar code. The stencil of the
subject invention will be, in fact, handled and inserted into a
mold just as other core inserts have been inserted into molds to
form features of the part for as long as casting and molding
processes have existed. The uniqueness of the present invention
lies in the sequential, or unique, codes punched, routed and
drilled, the one-time use of a particular stencil, the scalability
of the stencil, and the immense reliability of the bar codes marked
with the present invention. The stencil of the present invention
allows established manufacturing processes to be used a direct part
marking methodologies.
[0054] The type of material used to make carrier strip 40 will also
depend on the structural integrity requirements of the stencil
during manufacture of the article for which the stencil will be
used to identify. For example, during casting with molten metals,
temperatures can reach 3,500 degree F. For use in such an
environment, carrier 40 may be made from a ceramic fiber material
in order to provide the required resistance to high temperature. In
some applications, carrier strip 40 may also be subjected to
pressures as high as 5,000 PSI, either positive or negative. Thus,
the material used to make carrier 40 must be selected
accordingly.
[0055] In an environment where the stencil will not be subjected to
temperature extremes, for example, in an after market marking
process, carrier 40 may be made with lower temperature grade
materials.
[0056] At selected marker locations 42, a void is formed in carrier
40 in accordance with the particular bar code symbology to be used.
In essence, the voids allow the formation of data cells at the
appropriate point in accordance with the code symbology being used.
These voids can comprise cutouts which are formed fully through
carrier 40 or can be mere depressions created by a press or stamp.
FIG. 5 is a cross section of one void formed by a cutout and FIG. 6
is a cross section of a void formed by a depression. Cutouts may be
formed in carrier 40 using water jet cutting technology, laser
punching or cutting technology, or more commonly by blade cutting,
punching, or routing processes.
[0057] Applicant has discovered that the particular profile of the
void has a great deal of impact on the durability of the three
dimensional bar code formed when the stencil is used in a casting
or molding operation. Applicant has learned that a three
dimensional bar having a cross section as illustrated in FIG. 7 has
greater strength and durability than one having a rectangular cross
section as shown in FIG. 8. Thus, voids 42 are ideally formed in
carrier 40 with a cross section as illustrated in FIG. 9. FIGS.
10-13 illustrate other cross-sections which voids 42 may have in
accordance with the present invention.
[0058] When used in a cast or mold, the stencil may be attached to
a surface of the cast or mold using a number of attachment means,
including fastening clips, ties, nails or brads, adhesives, and
epoxy. Carrier 40 may also be formed of a material which has been
magnetized so that the carrier will naturally stick to the surface
of, e.g., a mold. Carrier 40 may also be provided with a double
back adhesive 11 for attachment purposes as shown in FIG. 14.
[0059] In the case where the stencil is attached using epoxy, the
stencil may be provided with an over laminate on the opposed side
in order to prevent the epoxy from entering the cut outs which form
the bar code bars. Or the data cell may be punched, routed, or
drilled only partially into the stencil material. FIG. 15
illustrates this application where reference number 20 refers to an
interior surface of, for example, a mold, to which an epoxy
material 21 is applied to hold stencil 23. An over laminate 22
prevents the epoxy material from entering the cut out.
[0060] FIG. 16 illustrates a bar code stencil which has been formed
by depressions 30 at selected marker locations. The stencil also
includes human readable digits 31 which correspond to the bar code.
Note that one end of each bar and digit character meet at a common
runner 32 and that the opposite edges correspond with the edges of
the stencil. Such a construction allows the stencil to be easily
used in a plastic mode with out flashing or incomplete formation of
the bar code or human readable digits.
[0061] Most often the stencil material will destruct during use,
but in certain instances the application process may not destroy
the stencil material. In those instances, an overlay, coating, or
laminate may be applied to the stencil to provide proof of singular
use. That is, in order to provide proof that the unique bar code
was used only once, the non-destructible stencil will have a
destructible overlay, coating, or laminate that will show evidence
of tampering, removal, or disturbance. Such an addition to the
stencil would allow audit of non-destructible stencils so as to
ensure the singular application of a unique bar code to an
individual part.
[0062] The bar code stencil and method of the present invention,
lend itself to a number of applications in many different
environments. These applications and environments are summarized
below but are not considered to be limiting.
Non-intrusive Point-of-Cast Stencil Insert for Casting Metal Parts
from Sand Molds
[0063] Cast metal marking of selected data symbologies can be
achieved by punching a pattern of the selected symbol out of
certain specific formula millboards, or other materials used for
core inserts, or core inserts themselves into which bar codes may
be punched, routed, or drilled. The punched stencils are then
placed into and secured in the sand mold. After the metal is
poured, the molded part is cooled, and the molds are `shook-out`,
the data symbology presents itself in three-dimensional form as
part of the casting.
[0064] The stencil insert may be either placed in a recessed cavity
in the sand mold, or not. FIGS. 17 and 18 illustrate this approach.
Methodologies for securing the stencil insert to avoid backcasting,
and to minimize outgassing will vary depending on the type of
metal, and range from glues and cements to nailing the stencil
insert to the sand mold.
[0065] The minimum size of the stencil insert is primarily limited
by the properties of the metals to be cast and the machining or
manufacturing processes to which the casting is subject. However,
once the properties of the metals are known, the stencil insert
process can be adjusted to achieve the preferred profiles for
reading the selected data symbology.
Non-intrusive Molding of Symbologies Through Use of Stencil Mold
Placed into a Chemical Bond
[0066] In this marking methodology a stencil is cut or punched from
a material selected for its non-bonding properties relative to the
chemical used as the mold medium. The mold medium is selected for
its bonding and longevity properties relative to the material
demanding the traceable data symbology. The process itself requires
the mold medium chemical to be applied to the part and before the
mold chemical `sets-up` the stencil is placed into the malleable
chemical. FIG. 19 illustrates this approach. After bonding and
hardening the non-stick stencil is removed, leaving a
three-dimensional data symbology on the part. Alternatively, the
stencil may be made of a non-release material. That is, the stencil
material may be used for other purposes such as coating or contrast
(for bar code readers). If the stencil is to be removed the date
cell wall sides may be sloped to achieve a data cell base larger at
the bottom in relationship to the top so as to promote easy
removal. Conversely, if the stencil is to remain in the mold
medium, the slope of the data cell bars may be reversed to aid in
the locking of the stencil in place.
[0067] The mold-a-code process is extremely flexible and only
limited by the conditions to which the selected part is subjected
or out of which the part is made. Likewise, the mold-a-code process
may be used in a molding process, i.e., molded or die cast plastics
or chemical compounds, or in the direct part marking process where
the stencil is used to form a bar code in epoxies or other
chemicals which bond with or become part of the part marked. The
mold-a-code process may also be used with dissolvable stencil
materials such as plastics or waxes so that after the material used
to form the data cells of the bar code `sets` or hardens, the
stencil itself may be disposed of by melting or dissolving.
Non-intrusive Application of Symbologies By The Spraying of Heated
Metals Through a Cut or Punched Stencil
[0068] In this marking methodology a stencil is cut or punched from
a material selected for its properties relative to the application
of a thermal spray and the part to be marked. The process requires
the stencil to be secured against the part to be marked and for the
thermal spray to applied over the entire stencil. After application
of the thermal spray the stencil may or may not be removed,
depending on the characteristics of the stencil material, leaving a
three-dimensional data symbology on the part. FIG. 20 illustrates
this approach. The thermal spray process is extremely versatile and
adaptable, and may be used in manufacturing processes as well as
maintenance processes, rebuilding, and revitalization of parts.
Again, the stencil and the data cells are scalable in size and are
limited only by the properties of the thermal spray process and the
readers of the bar codes applied. Most importantly, while the
thermal spray's ignition or combustion point is high temperature,
it can be applied to something as fragile as a business card
without damage to the card.
Non-intrusive Application of Symbologies By The Spraying of Paints,
Rubbers, or Other Chemicals Selected for Bonding Properties to the
Surface To be Marked Through a Punched or Cut Stencil
[0069] In this marking methodology a stencil is cut or punched from
a material selected for its non-stick properties relative to the
chemical used as the marking medium. The process requires the
stencil to be temporarily secured against the part to be marked and
for the selected marking chemical to be sprayed, rolled, or
otherwise applied over the stencil. When the stencil is
removed--after the marking chemical has bonded--a three-dimensional
data symbology is left on the surface.
[0070] This process is primarily limited by the bonding properties
of the marking chemical and the conditions to which the marked part
is to be subjected.
[0071] Alternatively, the stencil may be made of a non-release
material. That is, the stencil material may be used for other
purposes such as coating or contrast (for bar code readers). If the
stencil is to be removed the date cell wall sides may be sloped to
achieve a data cell base larger at the bottom in relationship to
the top so as to promote easy removal. Conversely, if the stencil
is to remain in the mold medium, the slope of the data cell bars
may be reversed to aid in the locking of the stencil in place.
Non-intrusive Application of a High Contrast Routed Stencil to
Surfaces Under Existing Military Spec Application Processes
[0072] In this process a flexible material is chosen for its
longevity-under-harsh-conditions properties. The material will be
homogenous but bi-layered; each layer's color chosen to
appropriately contrast with the other. The selected data
symbologies are routed through the top layer into a portion of the
bottom layer leaving a highly contrasted, easily readable recessed,
or protruding code. Whether the symbology is recessed or protruding
depends on whether the code itself is routed, or whether the
surrounding area is routed and removed. After the stencil is
routed, it is applied according to existing military specifications
for harsh environment application for polyurethane, or
polyurethane-type, materials. In some instances, the bottom layer
(i.e., the side applied to the part) may have a border which is
perforated so that a thermal spray can be used to coat and embed
the border thereby achieving a double-bond (chemical and
mechanical) adhesion.
[0073] The bonding process and the conditions to which the marked
part is to be subjected while in use will define the specific
application regiment.
Non-intrusive Point-of-Cast Stencil Insert For Casting Metal Parts
in Investment Casting
[0074] Punching or routing a pattern of the data symbol out of wax
materials will achieve cast metal marking of data symbologies. The
punched wax stencils are then applied to the wax mold with an
adhesive or through a heat bonding process (`hot knife` for
example). The application of the punched or cut wax mold completes
the wax mold for dip. After the mold is dipped into whatever slurry
the investment caster selects and the mold material hardens, and
the wax is melted from the mold, the selected data symbology is
part of the mold.
[0075] The stencil insert may be either placed in a recessed cavity
in the wax mold, or not. Methodologies for securing the stencil
insert to avoid backcasting will vary depending on the type of
metal, the physical location at which the data symbol is desired,
and pouring requirements.
[0076] The minimum size of the stencil insert is primarily limited
by the properties of the metals to be cast and the machining or
manufacturing processes to which the casting is subject. However,
once the properties of the metals are known, the stencil insert
process can be adjusted to achieve the preferred profiles for
reading any data symbology.
Non-intrusive Point-of-Cast Stencil Branding For Casting Metal
Parts in Investment Casting
[0077] Punching or routing a pattern of a selected data symbol out
of plastic or plastic-type materials will achieve cast metal
marking of data symbologies. The plastic or plastic-type materials
are punched or routed, depending on the type of presentation
required, so that either the data symbology or a reverse image of
the data symbology results. The resulting data symbology stencil is
then pressed into the wax mold so that the data symbology or its
reverse image is `branded` into the wax mold. The branding of the
wax mold completes the wax mold for dip. After the mold is dipped
into whatever slurry the investment caster selects and the mold
material hardens, and the wax is melted from the mold, the selected
data symbology is part of the mold, and becomes part of the casting
when the molten metal is poured into the mold, and the mold is
destroyed..
[0078] The branding stencil may be either pressed into a recessed
cavity in the wax mold, or not.
[0079] The minimum size of the branding stencil is primarily
limited by the properties of the metals to be cast and the
machining or manufacturing processes to which the casting is
subject. However, once the properties of the metals are known, the
formation of the branding stencil process can be adjusted to
achieve the preferred profiles for reading any data symbology.
Non-intrusive Point-of-Cast Stencil Insert or Branding for Casting
Metal Parts in Lost-Foam Casting
[0080] Punching or routing a pattern of the data symbol out of foam
or materials compatible with casting foams will achieve cast metal
marking of data symbologies. Similar to investment casting, either
a stencil will be attached onto the foam surface so that the data
symbology will be formed as the foam is melted or dissolved, or a
stencil will brand the foam surface to achieve the same result.
Like investment casting, the data mark is achieved when the molten
metal is poured into the cavity created by the disposal of the
`lost foam.`
Chemical Doping of Casting or Molding Stencil Material
[0081] In all of the processes where casting stencils are routed,
punched, or cut into any stencil material, the stencil material may
be chemically altered or doped so that the part material coming
into contact with the stencil material will be semi-permanently or
permanently stained a contrasting color or texture from the areas
of the part material not in direct contact with the stencil. Part
material will be metals, plastics, i.e., anything made in a casting
or molding process. In the case of branding stencils in investment
and lost foam casting, the chemical doping causing the staining or
contrast may be transferred to the mold as the wax or foam is
dissolved.
Texturing of Stencil Material
[0082] In all of the processes where casting stencils are used in
any ferrous or non-ferrous metallic casting or molding process the
stencil material may be roughened or textured on the side coming
into contact with the cast surface so that a contrast texture shall
be placed into the part material coming into contact with the
roughened or textured stencil surface. The result of said
roughening or texturing will cause a contrast in the data symbology
surface and thus an easier `read` by certain scanning or reading
devices or technologies will result.
Bonding of Stencil Material to Cast Surface
[0083] In all the processes where casting stencils are used in any
ferrous or non-ferrous metallic casting process the stencil may be
chemically altered or enhanced to catalyze a bonding process of the
stencil material during the casting. The result of the bonding
process will be to hold the post-cast stencil in place for a period
of time, thus bringing about a contrast with the part of the cast
surface not coming into contact with the stencil material, all of
which will result in easier reading by scanning or reading devices
and technologies.
Use of Outgassing to Achieve A Mottled Cast Surface
[0084] In all the processes where casting stencils are used in any
ferrous or non-ferrous metallic casting process the stencil may be
chemically altered or enhanced to catalyze an outgassing reaction
to the surface of the casting coming into contact with the stencil
material. The result of the outgassing process will be to leave the
surface of the casting coming into contact with the stencil
material with a mottled surface (the result of gas bubbling during
the pour and set up of the molten metal) thus bringing about a
contrast with the part of the cast surface not coming into contact
with the stencil material, all of which will result in easier
reading by scanning or reading devices and technologies.
[0085] It should be obvious from the above-discussed apparatus
embodiment that numerous other variations and modifications of the
apparatus of this invention are possible, and such will readily
occur to those skilled in the art. Accordingly, the scope of this
invention is not to be limited to the embodiment disclosed, but is
to include any such embodiments as may be encompassed within the
scope of the claims appended hereto.
* * * * *