U.S. patent application number 09/206422 was filed with the patent office on 2002-07-18 for computer-produced carved signs and method and apparatus for making same.
Invention is credited to DUNDORF, DAVID M..
Application Number | 20020095236 09/206422 |
Document ID | / |
Family ID | 22146473 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020095236 |
Kind Code |
A1 |
DUNDORF, DAVID M. |
July 18, 2002 |
COMPUTER-PRODUCED CARVED SIGNS AND METHOD AND APPARATUS FOR MAKING
SAME
Abstract
The present invention concerns computer-produced carved signs
and methods and apparatus for making the same. A computer-produced
carved sign embodying a signage work having three-dimensional
surfaces, is produced by a method which comprises, designing on a
computer-aided design system, a three-dimensional graphical model
of the signage work having three-dimensional surfaces to be carved
in a signboard. On the computer-aided design system, a desired
mathematical representation of the three-dimensional graphical
model of the signage work to be carved in the signboard, is
determined, and the desired mathematical representation is provided
to a computer-aided machining system having a carving tool.
Material constituting the signboard is removed using the carving
tool moving under the controlled guidance of the computer-aided a
machining system, to leave in the signboard, a three-dimensional
carved pattern corresponding to the three-dimensional graphical
model of the signage work, wherein the three-dimensional
carved-pattern in the signboard has three-dimensional surfaces
corresponding to the three-dimensional surfaces of the
three-dimensional graphical model of the signage work.
Inventors: |
DUNDORF, DAVID M.; (SALEM,
CT) |
Correspondence
Address: |
THOMAS J PERKOWSKI ESQ P C
SOUNDVIEW PLAZA
1266 EAST MAIN STREET
STAMFORD
CT
06902
|
Family ID: |
22146473 |
Appl. No.: |
09/206422 |
Filed: |
December 7, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09206422 |
Dec 7, 1998 |
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08886733 |
Jul 1, 1997 |
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08886733 |
Jul 1, 1997 |
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08507153 |
Jul 26, 1995 |
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08886733 |
Jul 1, 1997 |
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07701445 |
May 15, 1991 |
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08886733 |
Jul 1, 1997 |
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07078832 |
Jul 28, 1987 |
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Current U.S.
Class: |
700/182 |
Current CPC
Class: |
G05B 19/4097 20130101;
G16Z 99/00 20190201; G05B 2219/36323 20130101; G05B 2219/35287
20130101; G05B 19/4069 20130101; G05B 2219/45212 20130101; Y02P
90/02 20151101 |
Class at
Publication: |
700/182 |
International
Class: |
G06F 019/00 |
Claims
What is claimed is:
1. A carved sign which comprises; a signboard, and a signage work
formed in said signboard and having three-dimensional surfaces
which have been formed by a carving tool simultaneously moving
along at least three programmable axes under the controlled
guidance of a computer-aided machining system.
2. The carved sign of claim 1 wherein said carving tool comprises
an axially rotating carving tool.
3. The carved sign of claim 1 wherein said signage work comprises
at least one of incised, relieved, and applique three-dimensional
surfaces.
4. The carved sign of claim 1 wherein said signage work comprises
at least one alphanumerical character having three-dimensional
surfaces characteristic of traditional gold-leafed hand-carved wood
signs.
5. The carved sign of claim 4 wherein said signage work comprises a
plurality of said alphanumerical characters.
6. The carved sign of claim 1 wherein said signboard comprises
material selected from the group consisting of wood, plastic,
metal, metal alloys, and combinations thereof.
7. The carved sign of claim 3 wherein said three-dimensional
surfaces bear a light reflective coating.
8. The carved sign of claim 7 wherein said light reflective coating
is a material selected from the group consisting of gold-leaf and
silver leaf.
9. A carved sign which comprises; a signboard, and a signage work
formed in said signboard and having three-dimensional surfaces
corresponding to a three-dimensional graphical model of said
signage work which has been produced on a computer-aided design
system.
10. The carved sign of claim 9 wherein said computer-aided design
system comprises a workstation; and a computer-aided design
computer, said workstation interfaced with said computer-aided
design computer.
11. The carved sign of claim 9 wherein said signage work comprises
at least one of incised, relieved, and applique three-dimensional
surfaces.
12. The carved sign of claim 9 wherein said signage work comprises
at least one alphanumerical character having three-dimensional
surfaces characteristic of traditional gold-leafed hand carved wood
signs.
13. The carved sign of claim 12 wherein said signage work comprises
a plurality of said alphanumerical charcters.
14. The carved sign of claim 9 wherein said signboard comprises
material selected from the group consisting of wood, plastic,
metal, metal alloys, and combinations thereof.
15. The carved sign of claim 11 wherein said three-dimensional
surfaces bear a light reflective coating.
16. The carved sign of claim 15 wherein said light reflective
coating is a material selected from the group consisting of
gold-leaf and silver leaf.
17. A method of forming a carved sign embodying a signage work
having three-dimensional surfaces, comprising: (a) designing on a
computer-aided design system, a three-dimensional graphical model
of said signage work having three-dimensional surfaces to be carved
in a signboard; (b) determining on said computer-aided design
system, a desired mathematical representation of said
three-dimensional graphical model of said signage work to be carved
in said signboard; (c) providing said desired mathematical
representation to a computer-aided machining system having a
carving tool; and (d) removing constituting material of said
signboard using said carving tool moving under the controlled
guidance of said computer-aided machining system, to leave in said
sign-board, a three-dimensional carved-pattern corresponding to
said three-dimensional graphical model of said signage work,
wherein said three-dimensional carved-pattern in said signboard has
three-dimensional surfaces corresponding to said three-dimensional
surfaces of said three-dimensional graphical model of said signage
work.
18. The carved sign of claim 17 wherein said desired mathematical
representation comprises a numerical coordinate data file
corresponding to a three-dimensional carving tool path for carving
said signage work.
19. The carved sign according to claim 17 wherein said method
further comprises after step (c), (d) applying a light reflective
coating to said three-dimensional carved pattern.
20. The method according to claim 19, wherein said light reflective
coating is one of gold leaf and gold paint.
21. The method according to claim 17, wherein said carving tool is
an axially rotating carving tool.
22. The method according to claim 17, wherein said signage work
comprises letters.
23. The method according to claim 17, wherein said computer-aided
design system comprises parametric spline-curve
representations.
24. The method according to claim 17, wherein said parametric
spline-curve representations are selected from the group consisting
of Cardinal spline surface representations and B-spline surface
representations.
25. The method according to claim 17, wherein said signage work
comprises an alphanumerical character having at least an outer
characteristic outline and wherein said three-dimensional graphical
model of said signage work comprises a three-dimensional graphical
representation of said alphanumerical character, said
three-dimensional graphical representation of said alphanumeric
character having three-dimensional surfaces.
26. The method according to claim 25, wherein said
three-dimensional graphical representation of said alphanumerical
character is generated from a corresponding two-dimensional
graphical representation of said alphanumerical character.
27. The carved sign according to claim 26 wherein said signage work
comprises a plurality of said alphanumerical characters.
28. The method according to claim 25, wherein each said
three-dimensional graphical representation of said alphanumerical
character is generated from a corresponding two-dimensional
graphical representation having a characteristic outline, by a
method which comprises the sequence of steps: (a) projecting in two
dimensions on said computer-aided design system, said
two-dimensional graphical representation of said character having
said characteristic outline; (b) generating from said
characteristic outline of said two-dimensional character, at a
predetermined offset towards the inside of said two dimensional
character, a plurality of substantially similar outlines of said
two-dimensional character and displaying said plurality of similar
outlines on said computer-aided design system; (c) projecting each
of said similar outlines, a predetermined distance along the third
dimension of the coordinate system of said computer-aided design
system; (d) introducing in said three-dimensional coordinate
system, a plurality of points at locations corresponding to points
along a three-dimensional tool path of an axially rotating carving
tool of predetermined carving dimensions which, when moved along
said three-dimensional tool path, forms in a signboard a desired
three-dimensional carved pattern having three-dimensional surfaces
corresponding to said three-dimensional surfaces of said
three-dimensional graphical structure of said alphanumerical
character; and (e) interpolating said plurality of points to render
the coordinates of said three-dimensional tool path, said
coordinates of said three-dimensional tool path corresponding to
said three-dimensional carved pattern associated with said
three-dimensional graphical representations of said two-dimensional
alphanumerical character.
29. A method of forming a carved sign embodying a signage work
including a component having three-dimensional surfaces,
comprising: (a) accessing from a memory storage means, a prestored
three-dimensional graphical model of said component of said signage
work; (b) providing said three-dimensional graphical model of said
component to a computer-aided machining system having a carving
tool; and (c) removing constituting material of said signboard
using said carving tool moving under the controlled guidance of
said computer-aided machining system, to leave in said signboard, a
three-dimensional carved pattern corresponding to said
three-dimensional graphical model of said component, said
three-dimensional carved pattern in said signboard having
three-dimensional surfaces corresponding to said three-dimensional
surfaces of said three-dimensional graphical model of said
component.
30. The method according to claim 29, wherein said component of
said signage work, is one of an alphanumeric character and a
shape.
31. The method according to claim 30, wherein said carving tool is
an axially rotating tool.
32. The method of claim 17, wherein said signage work includes the
three-dimensional surfaces of a preexisting physical object and in
step (a), said three-dimensional graphical model is produced by
holographically recording said physical object, storing said
holographic recording, and processing said stored holographic
recording as to provide said three-dimensional graphical model.
33. The method of claim 17 wherein designing said three-dimensional
graphical model in step (a) comprises measuring the coordinates of
the three-dimensional surfaces of a preexisting physical object
using three-dimensional coordinate measuring instrumentation.
34. The method of claim 33 wherein said three-dimensional
coordinate measuring instrumentation comprises one of a holographic
recording system and a laser-based non-contact height profiling
system.
35. The method of claim 33 wherein said three-dimensional
coordinate measuring instrumentation comprises a hand-held
three-dimensional digitizer that determines the coordinates of
points located on said physical object.
36. A method of generating on a computer-aided design system, a
three-dimensional graphical model of a three-dimensional character
from a corresponding two-dimensional character having at least one
characteristic outline, said method comprising the sequence of
steps: (a) displaying in two dimensions on said computer-aided
design system, said two-dimensional graphical representation of
said character; (b) generating from said outline of said
two-dimensional character, at a predetermined offset towards the
inside of said two dimensional character, a plurality of
substantially similar outlines of said two-dimensional character
and displaying said plurality of similar outlines on said
computer-aided design system; (c) projecting each of said similar
outlines, a predetermined distance along the third dimension of the
coordinate system of said computer-aided design system; (d)
introducing in said three-dimensional coordinate system, a
plurality of points at locations corresponding to points along a
three-dimensional tool path of an axially rotating carving tool of
predetermined dimensions, which when moved along said
three-dimensional tool path, provides in a signboard, a desired
three-dimensional carved pattern having a center line and
three-dimensional surfaces corresponding to the three-dimensional
surfaces of said three-dimensional graphical model; and (e)
interpolating said plurality of points to render the coordinates of
said three-dimensional tool path, said coordinates of said
three-dimensional tool path and said axially rotating carving tool
corresponding to said three-dimensional carved pattern associated
with said three-dimensional graphical model of said two-dimensional
character.
37. A three-dimensional graphical model produced by the method of
claim 36.
38. The method of claim 36 wherein said character is an
alphanumerical character.
39. The method of claim 38 wherein said predetermined dimensions of
said axially rotating carving tool includes a carving angle of
about between 60.degree. to 120.degree..
40. Method of generating on a computer-aided design system, a
three-dimensional graphical model of a three-dimensional character
from a corresponding two-dimensional character having at least one
characteristic outline, said method comprising the sequence of
steps: (a) displaying in two dimensions on said computer-aided
design system, said two-dimensional graphical model of said
character; (b) introducing interactively an array of control points
in three-dimensional space, (c) introducing interactively,
parametric spline surface representations, at locations
corresponding to three-dimensional curved surfaces of said
three-dimensional graphical representation of said two-dimensional
character, said characteristic outline providing boundary
conditions for said spline surface representation; and (d)
interpolating said array of control points, by said spline surface
representation so as to generate said three-dimensional graphical
model of said three-dimensional character.
41. The three-dimensional graphical model produced according to
claim 40.
42. Method of forming a three-dimensional carved pattern in a
signboard corresponding to a three-dimensional graphical model of a
signage work having three-dimensional surfaces, said method
comprising the sequence of steps: (a) generating on a
computer-aided design systems a three-dimensional graphical model
of a two-dimensional character having at least one characteristic
outline; (b) determining for a predetermined carving tool, a tool
path pattern for forming a three-dimensional carved pattern in a
signboard corresponding to said three-dimensional graphical model;
(c) providing said tool path pattern to a computer-aided machining
system having said carving tool; and (d) removing constituting
material of said signboard using said carving tool moving under the
controlled guidance of said computer-aided machining system, to
leave in said signboard, said three-dimensional carved pattern
corresponding to said three-dimensional graphical model of said
signage work, said three-dimensional carved pattern having
three-dimensional surfaces corresponding to said three-dimensional
surfaces of said signage work.
43. The carved pattern in a signboard produced by the method of
claim 42.
44. The method of claim 42 wherein said carving tool is an axially
rotating carving tool.
45. A method of generating on a computer-aided design system, a
three-dimensional graphical model of a signage work to be carved in
a signboard, said method comprising: (a) graphically representing a
signboard using solid geometry to provide a solid graphical model
thereof; (b) graphically representing a carving tool using solid
geometry to provide a solid graphical model thereof; (c) moving
said solid graphical model of said carving tool through said solid
graphical model of said signboard; (d) mathematically subtracting
those parts of said solid graphical model of said signboard that
are in mathematical union with said solid graphical model of said
carving tool during said movement thereof in step (c), as to form a
three-dimensional graphical model of a signage work in said solid
graphical model of said signboard; and (e) displaying said
three-dimensional graphical model of said signboard resulting from
step (d).
46. The method of claim 45 wherein said method further comprises
after step (e), generating a three-dimensional carving tool path
corresponding to the generation of said three-dimensional graphical
model of said signage work using said solid graphical model of said
carving tool.
47. The method of claim 46 wherein said method further comprises
generating a three-dimensional numerical coordinate data file
corresponding to said three-dimensional carving tool path.
48. The method of claim 17 wherein said three-dimensional graphical
model of said signage work is provided by the method of claim
45.
49. A carved sign embodying a three-dimensional work formed in a
signboard according to claim 48.
50. Apparatus for producing carved signs embodying a signage work
having three-dimensional surfaces, said system comprising: a
computer-aided design system for designing a three-dimensional
graphical model of said signage work to be carved in a signboard;
and a computer-aided machining system including a carving tool,
said computer-aided machining system receiving said
three-dimensional graphical model of said signage work and removing
constituting material of said signboard using said carving tool
moving under the controlled guidance of said computer-aided
machining system, to leave in said signboard, a three-dimensional
carved pattern corresponding to said three-dimensional graphical
model of said signage work, said three-dimensional carved pattern
in said signboard having three-dimensional surfaces corresponding
to said three-dimensional surfaces of said three-dimensional
graphical model of said signage work.
51. Apparatus for producing carved signs according to claim 50,
wherein said computer-aided design system further comprises a work
station including keyboard and a visual display unit.
52. Apparatus for producing carved signs according to claim 50,
wherein said computer-aided machining system further includes means
for controllably translating said carving tool with respect to the
entire signboard.
53. Apparatus for producing carved signs according to claim 51
wherein said means for controllably translating said carving tool
is a gantry-type structure having a machine tool carriage capable
of translating under numerical control, said carving tool through
at least three axes of simultaneous movement.
54. Apparatus for producing carved signs according to claim 52
wherein said means for controllably translating said machine tool
carriage is capable of translating under numerical control, said
carving tool through five axes of simultaneous movement.
55. Apparatus for producing carved signs according to claim 50,
wherein said carving tool is an axially rotating carving tool.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to methods and
apparatus for producing carved signs, and more particularly to
methods and apparatus for producing carved signs using
computers.
BACKGROUND OF THE INVENTION
[0002] Carving, dating long before paper was invented, can be
considered one of the earliest forms of writing. Letters carved in
wood provide a sense of warmth and a feeling of permanence, and can
focus the attention of viewers in a most dramatic way.
[0003] Dating well beyond the Colonial Period, traditional
hand-carved wood signs having gold-leafed lettering had found a
deep rooted place in our culture, and over the years the
manufacture of such signs has become a time-honored craft of the
signmaking arts. Wood chisels and special knives are the wood
crafters basic carving tools used in the time consuming process of
hand carving signage works in both relieved and incised modes of
carving. Traditionally gold or silver leaf coatings have been
applied to the relieved and/or incised surfaces of signage works,
so that natural as well as artificial light favorably reflects
therefrom to improve the visibility of the signage work, and to
display a sense of richness and accentuate the artistic beauty of a
signage work itself.
[0004] The conventional process for producing these hand-carved
gold-leafed wood signs is manual, slow and laborious, and although
expensive, they are of distinct beauty and treasured by many.
[0005] Yet while hand carved wood signs with gold-leaf lettering
are highly desired articles of manufacture, the traditional process
by which they have been made, has tended to make them time
intensive, too expensive and thus out of reach for the greater
number of persons who otherwise would desire to own such a sign
customized to their needs, interests and taste.
[0006] Hitherto, the art of making gold-leafed hand-carved wood
signs has retained its traditional method of manufacture, with the
exception of a minor development involving the use of an overhead
projector to transfer a layout pattern to prepared wood. Such a
layout transfer technique is described in Volume 15 of Fine
Woodworking, March 1979, in an article at pages 72-73 entitled
"Routed Signs: Overhead Projector Transfers Layout To Prepared
Wood" by Frederick Wilbur. Using architectural stick-on letters, a
few parallel lines and a design concept, a sign layout is mocked-up
on a piece of transparent plastic film. Using an overhead
projector, the layout is transferred onto the prepared wood.
[0007] In contrast with wood carving signmakers universally
eschewing, as a matter of convention, any and all
computer-assistance in practicing conventional methods of
manufacturing gold-leafed carved wooden signs, the signmaking
industry in general, has nevertheless been effected by the
application of computer-aided design, computer-aided manufacturing
and computerized numerical control technology.
[0008] Hitherto, several computer-aided signmaking systems
employing computer-aided design (CAD) and computer-aided
manufacturing and computer numerical control (CNC) based
technology, have been developed and are presently available.
[0009] However, such signmaking systems and methods using CAD/CAM
technology have been limited to the production of routed and
cut-out type signs. In contrast, because of its nature, the art of
carving traditional gold-leafed wood carved signs has remained in
the field of art wherein wood carvers use only gouges, knives,
chisels and hammers. Thus, it is now in order to briefly describe
in the following paragraphs, these inherently limited CAD/CAM
signmaking systems and methods.
[0010] Prior art computer-aided signmaking systems allow a
signmaker to design two dimensional signage works on
two-dimensional CAD systems, and to cut-out or route-in characters,
shapes, designs and parts thereof so designed, using cutting tools
moving under the guidance of a computer-aided machining system,
which includes, a computerized numerically controlled (CNC) axially
rotating routing tool. However, the cutting and routing functions
achieved by the prior art CAD/CAM signmaking systems are limited in
several significant ways.
[0011] In general, signage works formed into signboards by prior
art CAD/CAM signmaking systems, are routed thereinto by operation
of a routing tool moving in a single plane, with single pass
operations. The outlines of the characters are formed by a rotating
router tool bit moving in a plane, routing out uniform grooves in
the signboard within the plane. Notably, the uniform grooves formed
in the signboard, have the cross-sectional shape of the rotating
tool bit performing the routing operation, and are identical along
the entire lengths of the members of alphanumeric characters. In
some cases, multiple passes of the routing tool along the character
outlines is effected, often using tool bit offsetting, to provide
desired finished edges, slightly modifying the original uniform
groove so formed coextensively within a single plane. These routed
signs bear little if any resemblance to, and lack the surface
features of, traditional gold-leafed wood carved signs, the subject
to which the present invention is directed. one example of such
prior art signmaking apparatus is described in the sales brochure
for the "System 48 Plus" of Gerber Scientific Products, Inc. of
Manchester, Conn., wherein a computer-aided signmaking system is
disclosed. Specifically, the "System 48 Plus" signmaking system
comprises a computer-aided manufacturing system which includes a
gantry-type cutting machine which can cut or route-out letters up
to 24" high, or stencil-cut sign faces for backlighting. The
characters so formed from the system, are square cut or beveled,
with an optional finish cut. Also, the system provides control for
specifying the total depth of cut, and depth of each pass of the
router head. (See pages 4.74-4.76, IV System Operation of Gerber
Scientific Products' System 48 User's Manual, Document No.
599-020174, January 1986). However, while the "System 48 Plus"
signmaking system allows an operator to make any number of passes
from 0" to 2" inches deep for efficient routing and finer surface
finishes, the system is incapable of carving into a signboard, a
signage work comprising characters and designs having
three-dimensional incised and/or relieved surfaces for which
hand-crafted gold-leafed wood carved signs are noted. In
particular, the Gerber "System 48 Plus" is limited to 21/2 axes of
simultaneous cutting tool motion.
[0012] Another example of prior art signmaking apparatus is
described in the sales brochure for the "CSF 300 Computerized Sign
Fabrication System" of Cybermation Inc. of Cambridge, Mass. The
brochure discloses a CAD/CAM signmaking system including a router
head mounted to the carriage of a CNC gantry-type machine which is
limited to 21/2 axes of simultaneous motion. Sign layouts, either
computer-designed or conventionally laid out, are programmed and
can be called up at the machine by an operator. While the system
has a library of pre-programmed geometric parts (i.e., letters and
numbers in various typestyles) requiring the operator to enter only
the desired dimensions, such parts do not have the
three-dimensional features characteristic of traditional
gold-leafed hand-carved wood signs, nor is the CSF 300 system
capable of carving signs having such surface characteristics and
features.
[0013] Thus, in the art of computer-assisted design and manufacture
of signage works, the convention has been to use CAD systems to
design two-dimensional layouts of signage works to be cut-out of or
simply routed-in various signboard materials. In the latter
instance, the routed surfaces formed within a single plane of a
signboard, are limited to the cutting dimensions of the tool bit
employed and moving in the plane thereof.
[0014] Therefore, there is no teaching or suggestion of a
computer-aided method or system for producing carved signs
embodying signage works which have three-dimensional surfaces akin
to those characteristic of traditional hand-crafted gold-leafed
wood carved signs.
[0015] Accordingly, it is a primary object of the present invention
to provide a way of doing by computers and machines, that which was
done by hand in order to produce carved signs having
three-dimensional surfaces akin to those characteristic of hand
carved gold-leafed wood carved signs.
[0016] Another object of the present invention is to provide a
computer-aided method of producing carved signs which embody
signage works having three-dimensional incised and/or relieved
surfaces, characteristic of traditional gold-leafed hand-carved
wood signs.
[0017] It is a further object of the present invention to provide a
method of producing carved signs resembling traditional hand-carved
gold-leafed wood signs, wherein the method uses an integration of
computer-aided design (CAD), computer-aided machining (CAM), and
computerized numerical control (CNC) technology.
[0018] The present invention provides a design and manufacturing
method for providing computer-produced carved signs embodying
signage works having complex three-dimensional surfaces.
[0019] A principal advantage of the method hereof is it allows
production of a prototype carved sign within only a few minutes
after the design has been completed. As for small volume or
customized production, the method requires at most, only a few
hours of design time and a few minutes of manufacturing time per
carved sign.
[0020] Another object of the present invention is to provide a
carved sign embodying a signage work formed in a signboard by an
axially rotating carving tool simultaneously moving along at least
three programmable axes under the controlled guidance of a
computer-aided machining system.
[0021] A further object of the present invention is to provide a
computer-aided method of producing carved signs embodying signage
works comprising characters shapes and designs having
three-dimensional incised and/or relieved complex surfaces.
According to the present method, the characters are designed on a
computer-aided design system by creating a three-dimensional
geometric model thereof, and are carved into a signboard using a
carving tool moving under the guidance of a computer-aided
machining system.
[0022] Another object of the present invention is to provide a
carved sign produced by such computer-aided method of design and
manufacture.
[0023] It is an even further object of the present invention to
provide a CAD/CAM system for producing carved signs embodying
signage works having three-dimensional incised and/or relieved
curved surfaces. An advantage of the design and manufacturing
method of the present invention is that a signage work represented
by a three-dimensional graphical and numeric model can be exactly
reproduced, as a carving in signboards, thereby allowing the use of
such three-dimensional signage works as trademarks and service
marks, registered with the United States Patent and Trademark
Office.
[0024] A further object of the present invention is to provide a
method of generating on a computer-aided design system,
three-dimensional computer graphic (or, geometric) models (and
numerical coordinate data files for corresponding three-dimensional
carving tool paths) of three-dimensional characters generated from
traditional two-dimensional characters. Such computer-aided design
method can be used with the method and system for producing carved
signs hereof.
[0025] Another object of the present invention is to provide a
method of designing three-dimensional graphical models (i.e.,
representations) and numerical coordinate data files of
three-dimensional characters generated from two-dimensional
characters, using parametric spline-curve and/or spline-surface
representations in interpolating curves and surfaces,
respectively.
[0026] Another object of the present invention is to provide a
method of manufacturing, carved signs embodying signage work having
been recorded from preexisting physical objects using
three-dimensional surface coordinate measuring methods and
apparatus (e.g., instrumentation), based on principles including
laser-ranging, and holography.
[0027] An even further object of the present invention is to
provide a method of generating three-dimensional graphical
representations and corresponding numerical coordinate data files
of a signage work wherein such method employs a computer-aided
three-dimensional solid image processing program on the CAD system
hereof. This method provides a designer with the capability of
precisely mathematically subtracting (e.g., using a computational
process on the CAD system), three-dimensional solid stock material
from a three-dimensional solid model of a signboard which is in
mathematical union with the solid model of a carving tool that is
translatable within the CAD systems' three-dimensional coordinate
system, using a three-dimensional or two-dimensional stylus or a
mouse. In at particular, this method involves providing a solid
geometric model (i.e., three-dimensional solid graphical
representation) of a carving tool and of signboard constituting
material, and performing therewith, three-dimensional solid-image
processing. A principal advantage of this CAD method is that it
provides a highly flexible way in which to render a desired
three-dimensional model (e.g., graphical representation) from which
can be generated, numerical coordinate data file(s) for a
three-dimensional composite tool path corresponding to a signage
work to be carved in a real signboard using a particular carving
tool or tools of the present invention.
[0028] Yet a further object of the present invention is to provide
a computer-aided carved sign design and manufacturing system on
which the methods hereof can be computer-programmed, and wherein
the design and manufacturing system comprises in part, a
computer-aided design system that can automatically generate and
display a computer-simulation of the carving tool motion required
to produce the desired signage work carved in a signboard. The
design and manufacturing system of the present invention also
includes a computer-aided carving system having at least a
three-dimensional numerical control (NC) machining (i.e., tool
path) program, supported by a CAD/CAM computer.
[0029] Other and further objects will be explained hereinafter, and
will be more particularly delineated in the appended claims, and
other objects of the present invention will in part be obvious to
one with ordinary skill in the art to which the present invention
pertains, and will, in part, appear obvious hereinafter.
SUMMARY OF THE INVENTION
[0030] The present invention uses an integration of computer-aided
design, computer-aided manufacturing, and computer numerical
control technology to provide a computer-aided design and
manufacturing process for producing carved signs having surface
properties and features characteristic of traditional hand-crafted
gold-leafed wood carved signs.
[0031] In accordance with the principles of the present invention,
the method for producing carved signs hereof comprises designing on
a computer-aided design (CAD) system, a three-dimensional graphical
model (i.e., representation) of a signage work having
three-dimensional surfaces to be carved in a signboard. On the
computer-aided design system, a desired mathematical (e.g.,
numerical) representation of the signage work is determined.
Thereafter, the desired mathematical representation, which can be
in one of many possible and desirable formats, is provided to a
computer-aided machining (CAM) system including a CNC machine tool
having a carving tool. The material constituting the signboard is
removed using the carving tool moving under the controlled guidance
of the computer-aided machining system, to leave in the signboard,
a three-dimensional carved pattern corresponding to the
three-dimensional graphical model of the signage work. The
three-dimensional carved pattern in the signboard has
three-dimensional surfaces corresponding to the three dimensional
surfaces of the three-dimensional graphical model of the signage
work.
DESCRIPTION OF THE DRAWINGS
[0032] For a further understanding of the objects of the present
invention, reference is made to the following detailed description
of the preferred embodiment which is to be taken in connection with
the accompanying drawings, wherein:
[0033] FIG. 1 is a perspective view of an example of the design and
manufacturing equipment required to provide a carved sign
manufactured in accordance with the preferred embodiment of the
design and manufacturing method of the present invention;
[0034] FIG. 2 is a schematic block diagram of the computer-aided
design and manufacturing system for producing carved signs hereof,
shown in FIG. 1;
[0035] FIG. 3A is a perspective view of a carved sign produced by
the method hereof, showing the emulated geometrical features of
traditional hand-carved wood signs;
[0036] FIG. 3B is an elevated cross-sectional side view of a
carved-signboard embodying a signage work produced by the method
hereof illustrating the three-dimensional nature of the "center
line" curves of the carved grooves incised therein;
[0037] FIG. 4A is a plan view of a two-dimensional graphical model
(i.e., representation) of a layout of an alphanumerical signage
work displayed on the high-resolution color graphics display
terminal of the computer-aided design system hereof;
[0038] FIGS. 4B and 4C are different scaled perspective views of a
three-dimensional graphical model of components of the signage work
"SAGAMORE" shown in FIG. 3A, which are typically displayed on the
color graphics display terminal during the process of generating
three-dimensional graphical representations of alphanumerical
characters from two-dimensional graphical representations (e.g.,
characteristic outlines) thereof, in accordance with the principles
of the present invention;
[0039] FIGS. 4D and 4E are different scaled perspective views of
three-dimensional composite carving tool paths, shown in
association with respective characteristic outlines of the
three-dimensional graphical models of the alphabetical characters
"SA" illustrated in FIGS. 4B and 4C;
[0040] FIG. 4F is a plan view of a three-dimensional graphical
model of the numerical character of the numerical character "40" of
the signage work of FIGS. 3A and 4A hereof;
[0041] FIG. 4G is a perspective view of the three-dimensional
graphical model of the numerical character "40" illustrated in FIG.
4F;
[0042] FIG. 4H is a side view of the three-dimensional graphical
model of the numerical character illustrated in FIGS. 4F and
4G;
[0043] FIGS. 41 and 4J are different perspective views of three
dimensional composite carving tool paths graphically shown in
association with the characteristic outlines of the
three-dimensional graphical models of the numerical character "4"
illustrated in FIGS. 4F, 4G, and 4H hereof;
[0044] FIG. 4K is a perspective view of the three-dimensional
composite carving tool paths graphically shown in association with
respective characteristic outlines of three-dimensional graphical
models of three alphanumeric characters "SA 4" illustrated in FIGS.
4A, through 4J hereof; and
[0045] FIG. 5 is a chart showing several conventional sweeps of
gouges and chisels positioned alongside corresponding tool bits for
use with the axially rotating carving tool hereof, as to emulate
conventional carving operations using method and apparatus of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] It is now in order to describe in a best mode embodiment,
the details of the design and manufacturing method and apparatus
for producing carved signs embodying signage works having
three-dimensional incised and/or relieved carved surfaces, in
accordance with the principles of the present invention.
[0047] Referring now to FIG. 1, therein is shown an example of a
computer-produced carved sign (CPCS) design and manufacturing
system 1, although many different system configurations are
possible and would be evident hereinafter to those skilled in the
art. From this description, for purposes of illustration, the CPCS
system 1 includes a computer-aided design/computer-aided machining
(CAD/CAM) work station 2, a CAD/CAM computer 3 including software
packages, and a CAM system
[0048] The CAD/CAM work station 2 includes a keyboard 5 for
providing instructions and data to the CAD/CAM computer 3 via a
connection 6. For reviewing the design, a three-dimensional
high-resolution color graphics display unit 7 having a view screen
8 is part of the CAD/CAM work station 2. In the preferred
embodiment, the three-dimensional high resolution color graphics
display terminal, can be the Iris 3030 workstation from Silicon
Graphics, Inc. of Mountain View, Calif.
[0049] As illustrated in FIG. 2, the CAD/CAM work station 2 can be
designated as having several other computer-assisted design tools,
such as three and two-dimensional "object" coordinate measuring
apparatus, and methods used in connection therewith. An example of
two-dimensional coordinate measuring apparatus would be a digitizer
tablet 9, and an example of three-dimensional coordinate measuring
apparatus 25 would be the Cyberscan.TM. laser-based non-contact
height profiling system, available from Cyberoptics, Inc. of
Minneapolis, Minn.
[0050] As illustrated in FIG. 1, the CAD/CAM computer 3 is shown as
a single unit although it may comprise separate systems available
from many different manufacturers. The CAD/CAM computer 3 is
connected by a connection 10 to the CAM system 4. Information
developed on the computer 3 can be optionally transported to the
CAM system 4 on standard commercial magnetic media in the
appropriate computerized language formats numerically controlled.
Alternatively, connection 10 be realized using a modem in
accordance with conventional telecommunication principles (e.g.,
using the telephonic circuits, microwave and/or satellite links).
As will be discussed in greater detail hereinafter, the CAD/CAM
computer 3 can be used for either manual, semi-manual, or automatic
generation of carving tool paths, based on the geometry of a part
developed in the CAD/CAM computer during the CAD phase.
[0051] The CAM system as defined herein, is shown in the preferred
embodiment as having a gantry-type carving tool 11 mounted over a
vacuum type work table 12 on order of the size of a typical
signboard used in outdoor commercial environments, such as in front
of a law office or other professional building, but it can be much
larger or smaller. The carving tool 11 in the preferred embodiment,
comprises an axially rotating carving tool, such as an electric or
pneumatic router head, which is mounted to a carriage 13 that moves
along the gantry structure 14 in response to three-dimensional
"carving tool path" instructions provided thereto. In the preferred
embodiment, the carving tool 11 is provided with five programmable
axes of simultaneous motion.
[0052] In order to properly practice the computer-assisted design
and manufacturing method of the present invention, the carving tool
11 need only have at least three programmable axes of simultaneous
motion. However, while in the preferred embodiment of the present
invention, three-programmable axes of simultaneous carving tool
movement can be employed, five or seven programmable axes of
simultaneous carving tool movement can provide certain advantages
when carving particular types of three-dimensional signage works.
Three, five, and seven axes gantry-type machine tools are available
from Thermwood Corporation, of Dale, Ind. In particular, the
Thermwood Cartesian 5 Aerospace model having five axes of
programmable motion, features a computer numerical controller
(i.e., machine control unit) from the Allen-Bradley Corporation,
having bubble memory and milling software. The table size available
with such a model is 71/2 feet by almost 16 feet, the vacuum
feature making it most suitable for accurately holding down a
signboard with repeatability.
[0053] The CAM system 2 also includes a computer numerical
controller (CNC) referred to hereinafter as the machine control
unit (M.C.U.) shown in FIG. 2. The CAM system 2 is in addition to
other mechanical material removal systems such as drills, routers,
sanders and the like which can find auxiliary application in carved
sign manufacturing operations.
[0054] Referring now to FIG. 2, there is shown a schematic block
representational diagram of the CPCS design and manufacturing
system 1 of the present invention. As shown in FIG. 1, the system
of FIG. 2 also comprises the CAD/CAM work station 2, the CAD/CAM
computer 3, machine control unit 15, gantry-type carving tool with
axially rotating carving tool 11 and also "a post processor" 16. It
also is shown to include a Graphics Library 17, realized as a
computer data base in communication with the CAD/CAM computer 3. In
order to provide hardcopy print-outs (i.e., plots) of a
three-dimensional graphical or numerical models of signage works, a
plotter/printer unit 20 can be provided. Alternatively, screen
image reproductions can be provided by photographic equipment.
[0055] The Graphics Library 17 contains symbolic representations,
such as numerical coordinate tool path data files,
three-dimensional geometrical and graphical (e.g., curve, surface,
and solid) models, design documentation and the like, of signage
parts including characters, shapes and designs previously designed
or otherwise provided. The symbolic representations stored in the
Graphics Library 17 hereof can be (i) generated on the CAD/CAM
system 1 in accordance with the computer-assisted (and automated)
design methods of the present invention, and then (ii) stored in
the computer data base 17. Alternatively, the symbolic
representations in Graphics Library 17 can be produced with the aid
of three and two-dimensional coordinate measuring methods and
apparatus to be described in detail hereinafter. Thereafter they
can be called up by a designer at the work station 2 and
concatenated with others, using the keyboard of the workstation to
display inventory files on the viewing screen of the 3-D color
graphics display unit 7. Alternatively, the symbolic
representations of characters, shapes and designs after having been
generated in accordance with the methods hereof, can be copied,
post-processed, and used on other CAD/CAM systems once the original
design work has been achieved. Greater details regarding use of the
Graphics Library 17 in the step involving designing signage works
to be carved in signboards, will be given in a later section of
this Description.
[0056] Referring to FIG. 3A, there is shown a perspective view of a
signboard embodying a three-dimensional carved pattern produced by
the design and manufacturing method and using the apparatus of the
present invention. FIG. 3A illustrates how with the
computer-assisted carving method of the present invention, the
"width" of carved grooves can be made to vary in the x-y plane. In
FIG. 3B, a cross-sectional view of the carved sign of FIG. 3A taken
along the line 3B-3B, is shown. This cross-sectional view
illustrates the potentially complex nature of the surfaces. More
particularly, this view illustrates how the depth of carved "V" and
other shaped grooves of a signage work can be made to vary along
the z axis as a function of x, y coordinates in the x-y plane.
Using the design and manufacturing method of the present invention,
virtually any type of signage work having simple or complex
three-dimensional surfaces, can be represented as a
three-dimensional graphical model on the CAD system of the present
invention, and carved into a signboard using, the carving tool of
the computer-aided machining system thereof, governed by a desired
mathematical representation generated from the three-dimensional
graphical model.
[0057] At this juncture, it is now in order to briefly describe the
mathematical basis underlying the geometrical and graphical
modeling and graphical display of curves, surfaces, and solids
comprising the computer-generated three dimensional graphical
models of the present invention in particular, and
three-dimensional mathematical representations of signage works and
components thereof, in general.
[0058] In the preferred embodiment, curve, surface and solid
generation facilities are provided for representing curved lines,
surfaces, and solids drawn in three-dimensional space. The
following section hereof describes the mathematical basis for the
three-dimensional curve and surface facilities of the system of the
present invention.
[0059] For purposes of illustration and not of limitation, the
CAD/CAM computer system and work station of the present invention,
can be realized (i.e., implemented) using the CAMAND 3000
Series.TM. CAD/CAM System by Camax Systems, Inc. of Minneapolis,
Minn. The CAMAND.TM. 3000 Series CAD/CAM Computer System can
include the 3030 Iris Series super workstation from Silicon
Graphics of Mountain View, Calif., providing state-of-the-art
capabilities for high level CAD/CAM usage. This three-dimensional
engineering/designing workstation can provide the user with a rapid
response time with real-time color graphics display, shading
capabilities, multi-windowing, and multi-tasking capabilities.
[0060] The CAMAX CAD/CAM System includes CAMAND.TM. Software that
provides sufficient CAD/CAM capabilities for the design and
manufacturing of computer-produced carved signs having surface
features characteristic of traditional gold-leafed hand carved wood
signs. CAMAND.TM. Software includes comprehensive features which
are suitable for three-dimensional graphic (or geometric) modeling,
design analysis, documentation, and multi-axis numerical control
programming of carved signage works to which the present invention
is directed.
[0061] As an alternative to CAMAND 3000 Series.TM. System from
CAMAX Systems, Inc., the CAD system of the CPCS System hereof can
be realized (i.e., implemented) using the ANVIL.TM.-5000 CADD/CAM
Software System including the OMNISOLID.TM. Solid Modeling Software
System of Manufacturing and Consulting Services, Inc. (hereinafter
MCS) of Irvine, Calif. The MCS ANVIL.TM.-5000 CADD/CAM System is a
fully integrated 3-D CADD/CAM software package which provides
wireframe, surface and solid modeling, finite-element mesh
generation, analysis, drafting, and numerical control using the
same integrated database structure and the same interactive
interfaces.
[0062] MCS's OMNISOLIDS.TM. Solids Modelling Software module is a
Constructive Solid Geometry (CSG)/Boundary-Representation (B-REP)
hybrid system which allows full use of all sculptured surfaces. The
data structure of OMNISOLIDS.TM. Solid Modelling Software Module is
a GSG/B-REP hybrid. CSG is a method of storing a solid as a series
of unions, intersections and differences of simpler solids, or
primatives. B-REP, Boundary Representation, is a method of storing
the faces (i.e., surfaces) of the solids. The OMNISOLIDS.TM. Solid
Modelling Software Module utilizes a combination of these two
storage techniques.
[0063] The mathematical basis for three-dimensional curve facility
of the preferred embodiment hereof, is now given with respect to
the Iris.TM. curve facility of the CAMAND 3000 Series.TM. CAD/CAM
Computer System.
[0064] A curve segment is drawn by specifying a set of four
"control points", and a "basis" function which defines how the
control points will be used to determine the shape of the curve
segment. Complex curved lines in three-dimensions representive of
carving tool paths (e.g., character "center lines"), and the like,
can be created by joining several curve segments end-to-end. The
curve facility provides the means for making smooth joints between
the curve segments.
[0065] For purposes of the present disclosure, the term "center
line" will be hereinafter used much in the way that it is
conventionally referred to in Fine Woodworking's On Carving and How
to Carve Wood, both works published by Taunton Press.
[0066] The mathematical basis for the curve facility of the
preferred embodiment, can be the parametric cubic curve. The curves
in the present application which correspond to the
three-dimensional "centerline" trough (of carved grooves in the
signboard), are often too complex to be represented by a single
curve segment and instead must be represented by a series of curve
segments joined end-to-end. In order to create smooth joints, it is
necessary to control the positions and curvatures at the end points
of curve segments to be joined. Parametric cubic curves are the
lowest-order representation of curve segments that can provide
continuity of position, slope, and curvature at the point where two
curve segments meet.
[0067] A parametric cubic curve has the property that x, y, z can
be defined as third-order polynomials for some variable t:
x(t)=a.sub.xt.sup.3+b.sub.xt.sup.2+c.sub.xt+d.sub.x
y(t)=a.sub.yt.sup.3+b.sub.yt.sup.2+c.sub.yt+d.sub.y
z(t)=a.sub.zt.sup.3+b.sub.zt.sup.2+c.sub.zt+d.sub.z
[0068] A cubic curve segment is defined over a range of values for
t (usually o.ltoreq.t.ltoreq.1), and can be expressed as a vector
product.
c(t)=a t.sup.2+b t.sup.2+c t+d
[0069] 1 c ( t ) = [ t 3 t 2 t 1 ] [ a b c d ] c ( t ) = T M
[0070] The curve facility hereof can approximate the shape of a
curve segment with a series of line segments. The end points for
all the line segments can be computed by evaluating the vector
product c(t) for a series of t values between 0 and 1. The shape of
the curve segment is determined by the coefficients of the vector
product, which are stored in column vector. These coefficients can
be expressed as a function of a set of four control points. Thus,
the vector product becomes
c(t)=TM=T(BG)
[0071] where G is a set of four control points, or the "geometry",
and B is a matrix called the "basis". The basis matrix B is
determined from a set of constraints that express how the shape of
the curve segment relates to the control points. For example, one
constraint might be that one end point of the curve segment, is
located at the first control point. Another constraint could be
that the tangent vector at that end point lies on the line segment
formed by the first two control points. When the vector product C
is solved for a particular set of constraints, the coefficients of
the vector product are identified as a function of four variables
(the control points). Then, given four control point values, the
vector product C(t) can be used to generate the points on the curve
segment. For a detailed discussion of the various classes of cubic
curves, including Cardinal Spline, B-Spline and Bezier Spline curve
representations, reference can be made to the publication
"Parametric Curves, Surfaces, and Volumes in Computer Graphics land
Computer-Aided Geometric Design" (November, 1981) by James H.
Clark, Technical Report No. 221 Computer Systems Laboratory,
Stanford University, Standford, Calif.
[0072] Attention is now accorded to the mathematical basis for the
surface facility of the present invention, which in the preferred
embodiment, can be the Iris.TM. surface facility. Three-dimensional
surfaces, or patches, are presented by a "wire frame" of curve
segments. A patch is drawn by specifying a set of sixteen control
points, the number of curve segments to be drawn in each direction
of the patch (i.e., precision), and the two "bases" which define
how the control points determine the shape of the patch. Complex
surfaces can be created by joining several patches into one large
patch using the surface facility the method for drawing
three-dimensional surfaces is similar to that of drawing curves. A
"surface patch" appears on the viewing screen as a "wire frame" of
curve segments. The shape of the patch is determined by a set of
user-defined control points. A complex surface consisting of
several joined patches, can be created by using overlapping sets of
control points and B-spline and Cardinal spline curve bases.
[0073] The mathematical basis for the surface facility of the
present invention, can be the parametric bicubic surface. Bicubic
surfaces can provide continuity of position, slope, and curvature
at the points where two patches meet. The points on a bicubic
surface are defined by parametric equations for x, y, and z. The
parametric equation for x is: 2 x ( st ) = a 11 s 3 t 3 + a 12 s 3
t 2 + a 13 s 3 t + a 14 s 3 + a 21 s 2 t 3 + a 22 s 2 t 2 + a 23 s
2 t + a 24 s 2 + a 31 st 3 + a 32 st 2 + a 33 st + a 34 s + a 41 t
3 + a 42 t 2 + a 43 t + a 44
[0074] (the equations for y and z are similar). The points on a
"bicubic patch" are defined by varying the parameters s and t from
0 to 1. If one parameter is held constant, and the other is varied
from 0 and 1, the result is a cubic curve. Thus, a wire frame patch
can be created by holding s constant several values, and using the
facility hereof to draw curve segments in one direction, and doing
the same for t in the other direction.
[0075] There are five steps in drawing a surface patch:
[0076] (1) The appropriate curve bases are defined. The Bezier
basis provides "intuitive" control over the shape of the patch,
whereas the Cardinal Spline and B-Spline bases allow smooth joints
to be created between patches.
[0077] (2) A basis for each of the directions in the patch, u and
v, must be specified. Notably, the u-basis and v-basis do not have
to be the same.
[0078] (3) The number of curve segments to be drawn in each
direction is specified, where a number of curve segments can be
drawn in each direction.
[0079] (4) The "precisions" for the curve segments in each
direction (i.e., u and v) must be specified. The precision is the
minimum number of line segments approximating each curve segment
and can be different for each direction. To guarantee that the u
and v curves segments forming the wire frame, actually intersect,
the actual number of line segments is selected to be a multiple of
the number of curve segments being drawn in the opposing
direction.
[0080] (5) Using appropriate "path" commands, as for example, of
the Iris.TM. Graphics Library, the surface is actually drawn. The
arguments to the "patch" command contain the sixteen control points
that govern the shape of the patch, and associated with the x, y,
and z of the sixteen control points, there is associated a
4.times.4 matrix, respectively.
[0081] Patches can be joined together to create the complex
surfaces of three-dimensional signage works, by using for example,
the Cardinal Spline or B-Spline bases, and overlapping sets of
control points. In addition, curves and surfaces can be "blended",
smoothed, filled and trimmed by mathematical processing.
[0082] For a discussion of the mathematical basis for the solid
model facility of the preferred embodiment hereof, reference can be
made to Chapter 3, Subchapter 4 entitled, "Parametric Volumes" of
James H. Clark's Technical Report No. 221, Computer Systems
Laboratory, Stamford University referred to hereinbefore.
[0083] Attention is now given to designing a signage work on the
computer-aided design system hereof in accordance with the
principals of the present invention. In realizing the design and
manufacturing method of the present invention, one of several
techniques can be used to design on the CAD system hereof,
three-dimensional graphical models (e.g., three-dimensional
geometrical representations and/or carving tool path data files) of
a signage work to be carved in a signboard. In each embodiment of
the method however, there exists a step of modeling in some form or
another, the geometry of the components of a three-dimensional
signage work, and determining an appropriate three-dimensional
carving tool path provided by NC programming, to render the carved
signage work in the signboard.
[0084] In developing the computer-assisted design and manufacturing
method of the present invention, careful study has been accorded to
the traditional tools of the wood carving signage craft. As
illustrated in FIG. 5, such tools include wood carving chisels and
gouges of various sweeps and sizes, and in particular, study has
been given to the ways in which the various carving functions
(i.e., involving traditional wood carving tools) can be emulated
using, for example, the axially rotating carving tool 11 having a
selected tool bit geometry, moved in three-dimensional space under
the controlled guidance of the CAM system of the present
invention.
[0085] Additionally, recognition is given to the fact that wood
carvers have cut the sides of the grooves (i.e., gouges) of letters
at angles ranging from 90.degree. to 120.degree. in order to form
the "V" shaped grooves of many tradionally hand-carved incised
letters. Notably, different wood carvers often select different
angles to form the "V" as to reflect light in a preferred manner.
In connection therewith, FIGS. 4C, 4D, 4E and 4K in particular,
clearly illustrate how the width of a three-dimensional carved
pattern (such as a groove) can be varied along a three-dimensional
center line interposed between the inner and outer character
outlines, by simultaneously controlling along the z axis, the
cutting depth (e.g., z coordinates) of a cutter bit as it is moved
along the three-dimensional carving tool path in the x-y plane of a
three-dimensional coordinate system.
[0086] Hereinbelow is described one method in particular which has
been developed for carving letters and other alphanumeric
characters using the CPCS design and manufacturing system 1 and the
carving tool bits illustrated in FIG. 5. This computer-assisted
design method has been discovered to be a highly effective and most
efficient method for designing three-dimensional computer graphic
models and three-dimensional carving tool paths (including
numerical coordinate data) for characters, to be used in producing
three-dimensional carved patterns of three-dimensional signage
works in sign boards, wherein the carved patterns have incised
and/or relieved surfaces characteristic of traditional gold-leafed
wood carved signs. This particular method will now be described
below.
[0087] Referring to FIG. 4A, a two-dimensional computer graphic
model (i.e., representation) of a layout of a three-dimensional
signage work is presented in plan view as would appear on the
display terminal 7. FIGS. 4B and 4C illustrate in greater detail
two characters (i.e., components or parts) of a three-dimensional
signage work whose geometry is being modelled on the CAD system.
The three-dimensional graphical representations of the signage work
of FIGS. 4B through 4J, preferably are displayed on the viewing
screen 8 using high-resolution color graphics software.
[0088] Referring to FIGS. 4A and 4F through 4J, there is
illustrated several principal steps comprising a method of
generating three-dimensional graphical and numerical models of
three-dimensional characters from traditional or novel
two-dimensional characters or shapes, having "outer" (and sometimes
"inner") characteristic outlines 18 and 19 respectively. The
sequence of steps for this computer-aided design method will now be
described in detail.
[0089] As indicated in FIG. 4A, a two-dimensional graphical
representation (e.g., the "4" of "40 SAGAMORE") having "inner" and
"outer" characteristic outlines 19 and 18, is displayed (i.e.,
plotted) in two-dimensions (e.g., the x-y plane) on the CAD system,
such system preferably having high-resolution color graphics
capabilities. As a matter of design choice, the characteristic
outlines can be designated a particular color such as yellow.
[0090] As indicated in FIG. 4F, a plurality of substantially
similar outlines 18A of the two-dimensional character (e.g., 4) are
generated from the "outer" characteristic outline 18 and a
plurality of substantially similar outlines 19A from the "inner"
characteristic outline 19 thereof, at a predetermined offset (in
millimeters) in a direction towards the inside (i.e., towards the
centerline) of the two dimensional character. These "offsetted"
characteristic outlines 18A and 19A can be designated as purple,
for example.
[0091] As indicated from the characters of FIG. 4F, in particular,
there can arise from this computer graphic design process, the
formation of what will hereinafter be termed "islands", designated
by 21A, 21B, and 21C of the character "4" in FIG. 4F. In accordance
with the present invention, "island formations" can be thought of
as the void or vacant two-dimensional spaces remaining within the
space between the characteristic outer and inner outlines, 18 and
19 respectively, that is, after the outer and inner characteristic
outlines 18 and 19 converge to within a distance apart equivalent
to the offset distance. Notably, the character "0" of FIG. 4F has
no island formations.
[0092] When island formations arise in the process of generating
three-dimensional characters from two-dimensional characteristic
outlines of characters, shapes, designs and the like, then either
manual or programmed generation of "local" characteristic outlines,
e.g., 22A, 22B and 22C, for the "islands" 21A, 21B and 21C
respectively, must be generated. This procedure ensures that
complete three-dimensional graphical models of signage works and
components thereof can be provided. In such instances, the island
characteristic outlines 22A, 22B and 22C can be offset to generate
a plurality of island characteristic outlines as illustrated in
FIG. 4F.
[0093] The plurality of "inner" and "outer" similar outlines (i.e.,
offsets) illustrated in FIG. 4F in particular, are then displayed
on the CAD system's color graphics viewing screen, for review. The
general appearance of these geometrically similar outlines are that
of contour lines, of a contour map. But as will be illustrated in
the description of this particular method, providing such similar
outlines principally, although not solely, serve to help the
designer determine on the CAD system (i) the depth (e.g., z
coordinates) and (ii) the location (e.g., x, y coordinates) of the
three-dimensional "center line" curve of the three-dimensional
character produced from a transformed two-dimensional character,
projected into the three-dimensional space.
[0094] As illustrated in FIGS. 4G and 4H, each of the geometrically
similar outlines are then translated (i.e., projected), a
predetermined distance along the third dimension (e.g., z axis) of
the CAD systems' three-dimensional coordinate system. As mentioned
hereinabove, this step is helpful in assisting the designer to
determine the location where the three-dimensional "center line" of
the two-dimensional character will be drawn.
[0095] Thereafter, using the three-dimensional graphical model of
FIG. 4G, a plurality of points are interactively introduced in the
three-dimensional coordinate system, at locations corresponding to
points lying along what can be visualized to be a three-dimensional
tool path, along which the apex (i.e., tip) of an axially rotating
cutting tool of predetermined cutting dimensions, moves under the
guidance of the CAM system hereof. The interactive introduction of
points can be achieved using a "stylus" or "mouse" device well
known in the computer-aided design arts. These points are selected
so that when the axially rotating cutting tool 11 is moved along
the three-dimensional tool path, a desired three-dimensional carved
pattern having desired three-dimensional surfaces of a visualized
signage work, is formed in a signboard. Notably three-dimensional
surfaces of the carved pattern will correspond to the
three-dimensional surfaces of the three-dimensional graphical model
(i.e., representation) of the three-dimensional alphanumerical
character. As discussed in the curve mathematics section provided
hereinbefore, the plurality of points are then appropriately
interpolated using parametric spline-curve representations, to
render the coordinates of a composite three-dimensional carving
tool path 23 illustrated in FIGS. 4I and 4J. The carving tool path
23 when taken with a three-dimensional graphic model of a carving
tool, corresponds to the three-dimensional carved pattern that is
associated with the so designed three-dimensional graphical model
of the three-dimensional character. Thereafter, the interactively
introduced points can be erased for display purposes.
[0096] In connection with the above-described method of the present
invention, a three-dimensional graphical model and corresponding
numerical coordinate tool path data file(s) can be generated on the
CAD system hereof, from a corresponding two-dimensional graphical
model (e.g., characteristic outline) of the alphanumeric character.
The alphanumerical character can be of any sort regardless of type
style or font, and with or without serifs, a feature such as a fine
cross-stroke at the top or bottom of a letter. The
three-dimensional graphical representations, numerical coordinate
carving tool paths, and other mathematical representations derived
therefrom, once having been generated, can be stored in
non-volatile memory (e.g., ROM) and can be used to create the
data-base of the Graphics Library of the present invention, as
discussed hereinbefore with reference to FIG. 2B.
[0097] The tool path data file so generated by the above-described
design method, is then subject to post processing, an operation
which involves processing the tool path data file to produce
complete, machine-ready files, expressed in machine (i.e.,
assembly) or binary logical languages. In the post processor, the
tool path data is matched (i.e., interfaced) to a particular CNC
machine tool and machine control unit (MCU) combination. The output
of the post processor can be generated for paper tape, magnetic
memory storage or direct numerical control (DNC).
[0098] Notwithstanding post processing being a subject well known
and understood in the art of NC programming, reference is made to a
paper entitled "G-Posting To NC Flexibility", by the Computer
Integrated Manufacturing Company, of Irving, Tex., and reprints
from Modern Machine Shop of Cincinnati, Ohio. This paper provides a
further discussion on the "generalized post-processor approach"
utilized in simplifying NC workpiece programming and in making such
programs function on different makes of similar types of machine
tools.
[0099] In the preferred embodiment , the output of the post
processor corresponds to a three-dimensional composite tool path
data file, and three-dimensional graphical representations (i.e.,
models) of each alphanumerical character. The post processor output
can also be used to create the extensive Graphics Library of
numerous sets of three-dimensional alphanumerical characters of
distinct typestyles (i.e., fonts). The computer-software based
Graphics Library of the CAD/CAM sign carving system 1 of FIG. 2B,
can provide a robust inventory of three-dimensional characters. The
data files of these three-dimensional characters can be simply
accessed by a designer at the work station 2, for purposes of
designing a three-dimensional layout of a three-dimensional signage
work. Once designed, the three-dimensional graphical model of the
signage work can be displayed, reconfigured, and transformed to the
designer's liking, and after generation of three-dimensional tool
path data files and post processing thereof, provided to the CAM
system 4 in order to carve the corresponding three-dimensional
signage work into a signboard, by taking necessary and sufficient
steps.
[0100] In addition to the above-described method of designing
three-dimensional graphical models and tool path data files of
three-dimensional alphanumerical characters derived from
two-dimensional alphanumerical characters, an alternative method of
achieving the same has been developed. This alternative method will
now be described and explained below, after making a few
preliminary remarks appropriate at this juncture.
[0101] As discussed hereinbefore, the methods thus described
include that prior to carving any form of three-dimensional signage
work in a signboard, the geometry of the design of the signage work
is first specified by a computer graphic model from which
thereafter a numerical coordinate (three-dimensional tool path)
model is produced. In the present invention, the computer graphic
and numerical coordinate tool path models of a signage work are
prepared using computer-aided design and manufacturing techniques,
all of which are based upon computer graphics and computational
geometry, the latter being a subject which is given treatment in
"Computational Geometry for Design and Manufacturing (1980)" by I.
D. Faux and M. J. Pratt, published by John Wiley and Sons.
[0102] Notably, in the field of geometric (to be contrasted with
graphical) design, if the design of a three-dimensional signage
work has complex surfaces, as can many wood carved signage works,
then precise surface descriptions would need to be given for those
complex surfaces, prior to the determination of tool paths and the
output of the post processor. This therefore makes geometric
modeling using geometric primatives, a potentially time consuming
process in some cases, as the nature and precision of the surface
description given to a signage work is a question of mathematical
form. Mathematical form, on the other hand, is a matter regarding
the type of mathematical functions used to describe complex
three-dimensional curves, surfaces and solids of signage works,
wherein the three-dimensional surfaces thereof are characteristic
of traditional gold-leafed hand-carved wood signs, and which are to
be machine-carved in a signboard in accordance with the present
invention.
[0103] In contrast with geometric design, graphical design on the
CAD/CAM system of the present invention, can employ
three-dimensional coordinate measuring methods and aparatus, which
usually does not require production of geometric descriptions
(i.e., functions) and can produce numeric models of
three-dimensional objects to be carved in a signboard in accordance
with the principles of the present invention. The advantages of
each type of model used in computer-aided sign carving according
hereto, will hereinafter appear obvious to those with ordinary
skill in the art to which the present invention pertains.
[0104] It is also within the contemplation of the present
invention, that there can appear at times, the need to employ
additional modeling techniques based on alternative mathematical
structures and processes operationally supported within the CAD
system of the CPCS design and manufacturing system hereof. It has
been discovered that this is especially the case when desiring to
produce carved signs embodying signage works having
three-dimensional surfaces akin to those characteristic of
traditional hand-crafted gold-leafed wood carved signs in
particular, and having relieved and/or incised carvings of
characters and designs, in general.
[0105] In particular, in IEEE Computer Graphics and Applications
Journal of January 1984, a paper is presented entitled
"Computer-Integrated Manufacturing of Surfaces Using Octree
Encoding" by Yamaguchi et al. The paper presents an algorithm for
automatically generating from an octree description, numerical
coordinate tool paths containing the data that a numerical control
milling machine requires to manufacture a part. The octree data
structure, representing a three-dimensional object by
hierarchically organized cubes of various sizes, facilitates the
performance of boolean operations and tool and work piece
"interference" checking, and provides an approximate representation
of smooth surfaces to any required accuracy. Also, since the octree
model has a very simple data structure, the automatic generation of
various types of carving tool paths is possible. Accordingly, the
use of octree data structures, operations, and algorithms can be
used with the CPCS design and manufacturing system hereof, to
design three-dimensional graphical models of signage works having
three-dimensional incised and/or relieved surfaces.
[0106] When graphically modeling signage works having certain
surface topologies, it has been discovered that other CAD methods
can be advantageously employed in designing and manufacturing
carved signs in accordance with the principals of the present
invention.
[0107] Additionally, as discussed hereinbefore, the method of the
present invention, can make use of parametric spline-curve,
spline-surface, and spline-volume (i.e., solid) representations as
mathematical structures for geometric modeling of the
three-dimensional surfaces of a signage work. Examples of such
spline-curve and surface representations are defined and described
in the IEEE Computer Graphics and Applications Journal, in the
following articles: "Parametric Spline Curves and Surfaces" by B.
A. Barskey, February 1986; "Rational B-Splines for Curve and
Surface Representation" by Wayne Tiller, September 1983;
"Rectangular V-Splines" by G. M. Nielson, February 1986; "A
Procedure For Generating Contour Line From B-Spline Surface" by S.
G. Sutterfield and D. F. Rogers, April, 1985.
[0108] Herebelow, using one of several known or
yet-to-be-discovered parametric spline curve or surface
representations, an alternative method is presented for generating,
on the CAD system, a three-dimensional graphical model (i.e.,
representation) of a two-dimensional shape having at least one
characteristic outline. This method comprises displaying in two
dimensions on the CAD system, the two-dimensional graphical
representation of the characteristic outline of the shape. From
this two-dimensional graphical representation, the surface within
the "characteristic outline" thereof is subdivided into a plurality
of "surfaces patches", each of which can be independently created
and smoothly connected together using surface mathematics as
hereinbefore described. A spline surface representation of a
particular type, can be selected as a basis for patches of the
three-dimensional curved surfaces of the three-dimensional
graphical model (i.e., representation) generated from the
two-dimensional character. Interactively, an a array of control
points can then be introduced in three-dimensional space, to
control the desired shape of the parametric spline-surface
representations so to design the "surface patches" comprising the
three-dimensional graphical model generated from the
two-dimensional shape or character. The array of control points for
each surface patch, are then interpolated using a spline surface
representation to thereby generate the individual surface patches
comprising the three-dimensional graphical model. From the
resulting three-dimensional graphical model, a corresponding tool
path can be automatically or interactively (i.e., manually)
generated.
[0109] In connection with the design and manufacturing method of
producing carved signs in accordance with the present invention,
there are two prior art computer-aided methods which can be used in
the process of designing from two-dimensional alphanumerical
characters, three-dimensional graphical models thereof.
[0110] U.S. Pat. No. 4,589,062 to Kishi et al. incorporated herein
by reference, discloses a method of creating curved surfaces which
can be used in the design step involving the formation of
three-dimensional graphical models of components of
three-dimensional signage works. In particular, the method of U.S.
Pat. No. 4,589,062 is an "interactive" method, which involves
defining on a first section curve (e.g., characteristic outline), a
first correspondence point which corresponds to a second
correspondence on a second section curve (e.g., center line), and
then generating intermediate section curves in accordance with the
first and second correspondence points. In essence, such method
involves moving and transforming a first section curve of two given
section curves, until the first second curve is superposed on a
second section curve. The major advantages thereof is that curved
surfaces featuring subtle changes can be generated with increased
degrees of freedom and created with accuracy. According to the
present invention, the method of U.S. Pat. No. 4,589,062 can be
employed in the process of producing a three-dimensional graphical
model (i.e., representation) of a signage work in general, and
three-dimensional graphical model of a three-dimensional character
generated from a two-dimensional character having at least one
characteristic outline, in particular.
[0111] Another method which can be used in the design step of the
method of the present invention, involves automatically creating
three-dimensional sculptured surfaces from sectional profiles
designated on design drawings only. FAPT DIE-II software from
General Numeric of Elk Grove Village, Ill., provides such facility.
For sectional profiles, curves on an optional plane in a space are
classified into basic curves and drive curves. For example, assume
that one basic curve and two (i.e., first and second) drive curves
are designated on a design drawing. Sculptured surfaces are created
by gradually changing the profile of the first drive curve to the
second drive curve when the first drive curve moves toward the
second drive curve along the basic curve. As applied to the present
invention, the first and second drive curves can represent the
effective cross-sections of an axially rotating carving tool
disposed at two different points along the z axis herein. The basic
curve can represent the center line of a carved groove in a
signboard.
[0112] While the above methods of generating three-dimensional
graphical models of characters may satisfy most designers of
computer-produced carved signs, especially those designing signage
works limited to lettering, the present invention understands that
there are, nevertheless, CAD designers who desire to feature in
their three-dimensional signage works, shapes and designs other
than alphanumerical characters such as those commonly seen in
hand-crafted "chip" carvings. In such situations, the designer will
need to generate on the CAD system, three-dimensional graphical
models having complex three dimensional surfaces. In such an event,
the designers will require certain computer-assisted geometric
modeling and NC tool path generation capabilities. This is to
ensure that complex signage work components can be efficiently and
effectively designed, composite tool path graphics displayed, and
composite tool path numerical data generated therefrom and proven
by computer simulation on the CAD system or by carving signboards
with the CAM system of the present invention.
[0113] In accordance with the principles of the present invention,
the components of a complex signage work can be modelled with any
combination of "wire frame" and surface (or solid) primitives,
including spline curve and surface representations. From the
Graphics Library 17 in the system diagram of FIG. 2B, a designated
computer program can access previously recorded two and
three-dimensional graphical designs for creation of tool paths
which can be dynamically displayed and interactively joined, and
edited. This provides a visual representation of the exact tool
paths relating to the graphically designed part. The NC tool path
data can be in one of several formats, and an appropriate post
processor will produce either paper tape, or magnetic recordings,
or direct output for controlling the axially rotating carving tool
11 hereof preferably having five programmable axes of simultaneous
movement as described hereinbefore.
[0114] The present invention also contemplates that there are
instances when a designer will desire additional freedom in
designing a three-dimensional graphical model of a signage work,
that is, as compared with the above-described computer-aided design
methods. It has been discovered that in such instances, it may even
be desired to have the capability of representing
three-dimensionally -on the CAD system hereof, the removal of
"solid" signboard constituting material, as does a carver
skillfully utilizing conventional tools of the trade, such as
chisels, gouges and hammers. In connection with such design
capability, an alternative computer-aided design method has been
developed and will be described hereinbelow.
[0115] This alternative computer-assisted design and NC programming
method teaches "mathematically" subtracting (using Boolean
operations), solid "stock material" (i.e., signboard material)
representations from a signboard represented in the
three-dimensional CAD system, which uses a computer-aided carving
tool. Therein, the carving tool(s) is (are) represented on the CAD
system in the form of a "solid" three-dimensional graphical
structure representing the "effective" solid geometry of a
specified tool bit in operation. The carving tool is also displayed
on the visual display unit of the CAD system, and can be moved on
the screen using a joystick, light pen or other conventional
device. Between the three-dimensional images of the solid signboard
and carving tool bit, a computational-based "three-dimensional
image subtraction" process comprising "Boolean operations", is
performed to generate a three-dimensional graphical representation
of a signage work. Therefrom, tool path data associated with a
particular three-dimensional, graphically represented carving tool,
is automatically generated. The steps of the process are described
below.
[0116] Using solid geometry, the designer models (i.e., represents)
on the CAD system, the carving tool as well as the signboard and
then removes (i.e., mathematically subtracts) the from the solid
model of the signboard, the graphically represented stock material
of the solid signboard model, over which the solid models (i.e.,
numeric and graphics-based three-dimensional graphical
representations) of the carving tool bit and signboard, overlap. As
the three-dimensional carved patterns are being defined, both the
tool path graphics data and the tool itself can be displayed. At
the same time or thereafter, tool path numerical data files thereof
can be automatically generated using known computational
processes.
[0117] The process described hereinabove involves three-dimensional
solid-image subtraction and has the advantage of automatic tool
path generation. Thus, this method of designing three-dimensional
models of a signage work requires implementation of a
three-dimensional image subtraction technique realized by a
computer-aided process on the CAD/CAM computer 3. The
computer-aided process effectuates the removal of
three-dimensionally represented "solid" stock material in "union"
(i.e., overlapping in 3-D space) with the position of the solid
geometrical model of a carving tool (e.g. axially rotating carving
tool bit). With this process, the removal of solid stock material
in "union" with the solid carving tool model is achieved by
mathematical subtraction (i.e., difference calculations) from a
solid geometrical model of the signboard and in a manner which is
analogous in some respects to the modus operandi of sign carvers
employing manual, time-honored carving tools and procedures.
[0118] In realizing the above-described method, an enhanced version
of one of the CAMAX CAMAND.TM. and the MCS ANVIL-5000
OMNISOLIDS.TM. solid (i.e., volume) modeling computer software
program packages can be used to impliment the hereinabove described
design process of the present invention. With such a process, a
means is provided for mathematically or "computer graphically"
carving signage works and automatically generating numerical
coordinate tool path data therefor on the CAD/CAM system hereof. In
implimenting the above-described three-dimensional solid-image
subtraction/automatic tool path generation process, advantages can
be derived by using work station software from Weber Systems Inc.
of Brookfield, Wis. In particular, the work station software can
allow an operator/designer practicing the present invention, to
simultaneously view four different views of the Boolean-based
computational process involving solid models of the carving tool
and stock material (e.g., signboard).
[0119] In connection with the CAD method hereinbefore described,
focus is now given to FIG. 5 wherein examples of carving tool bits
of various geometries are illustrated, and which can be used with
the design and manufacturing method of the present invention.
Therein, the chart shows several conventional sweeps and gouges and
chisels positioned alongside corresponding tool bits for use with
axially rotating carving tool 11, which are capable of emulating
conventional hand carving operations in accordance with the
principles of the present invention. Also, as illustrated in FIG.
2, three-dimensional solid graphical (and numerical) models of the
various carving tool bits illustrated in FIG. 5 can be stored in
memory 24, and called up when desired by a designer or program.
[0120] The present invention also contemplates that there are
instances when a designer will desire to design (i.e., define) a
geometric model of a signage work using at least one or more of the
parametric curve, surface, and solid generation facilities of the
system hereof, and allow the CAD/CAM computer 3 to automatically
generate the tool path parameters (e.g., carving tool
specifications, numerical coordinate tool path data, spindle and
feed speeds, etc.), tool entry methods, and clearance planes, in a
language compatible with the post-processor available.
[0121] There will also be times when a computer-assisted designer
may desire to carve a three-dimensional pattern or design of a
preexisting "physical" object, alongside or around carved lettering
comprising in combination therewith, a composite signage work.
Realizing that creating a graphical (or geometrical) model of
preexisting physical objects requires substantial time at the work
station 2, a three-dimensional graphical and numerical model of
such signage work can be designed (i.e., provided) by recording the
coordinates of the three-dimensional surfaces of the physical
object to be carved in the signboard, as to produce a
three-dimensional graphical and numerical model of such signage
work or component thereof. Using automatic or manual tool path
generation techniques and one of several carving tools, a numerical
coordinate data file of a composite tool path therefor can be
produced.
[0122] This CAD technique offers the advantage of obviating the
need to manually generate a three-dimensional graphical model of
the physical object using computational geometry and the like, but
rather utilizes three-dimensional surface coordinate measuring
methodologies, based in part on principals of holographic imaging
and optical memory storage. In such instances, "three-dimensional
coordinate measuring" methods and apparatus can be used in the step
of designing (i.e., producing or providing) a three-dimensional
graphical model of a signage work, in accordance with the design
and manufacturing method of the present invention. In particular, a
laser-based non-contact height profiling system can be employed to
carry out methods of measuring three-dimensional coordinates of the
surfaces of a low profiled physical object (i.e., digitizing
three-dimensional objects) to be carved in a signboard. An example
of such three-dimensional coordinate measuring apparatus 25
diagrammatically illustrated in FIG. 2, is the Cyberscan.TM.
profiling system available from Cyberoptics Inc., of Minneapolis,
Minn. and as the corporate name suggests, optical principles can be
applied to achieve control processes. In the case of the present
invention, the control processes would be the CAM system 4 guiding
the carving tool 11 in accordance with carving tool paths generated
from a three-dimensional graphical model of the preexisting
physical object.
[0123] Another approach using three-dimensional coordinate
measuring methods and apparatus can involve utilization of
holographic recording methods and equipment. In such instances, a
three-dimensional graphical model can be produced by
holographically recording a physical object to be carved in a
signboard, using holographic equipment. The holographically
recorded image of the physical object can be stored and digitally
processed to provide in a suitable computer graphic format, a
three-dimensional graphical model of the physical object. From this
three-dimensional graphical model, suitable carving tool paths
(i.e., numerical data files) can be generated using either manual,
semi-manual or automatic tool path generation techniques.
[0124] Alternatively, a hand-held stylus called the "3 Space
Digitizer" from Polhemus Navigation Sciences, of Colchester, Vt.,
can be used to enter x, y, and z coordinate data of
three-dimensional physical objects or models, into a properly
interfaced CAD/CAM system. Using a Unigraphics.TM. CAD/CAM
workstation from The McDonnel Douglas Corporation, an alphanumeric
terminal initiates the digitizer task, and the 3 Space Digitizer
can be used to enter complex geometry of non-metallic objects
(e.g., to determine the x, y, and z coordinates of points located
on a 3D model or object). The 3D Space Digitizer transmits this
data to a host computer which includes a C.P.U., tape drive, and
disk drive, and stores data in user-specified part files and
interfaces with the Unigraphics.TM. workstation.
[0125] The 3D Space Digitizer can be used to measure the
coordinates (i.e., digitize the space dimensions) of
three-dimensional physical objects that are to be made part of
signage works, employing one or more of incised, relieved, or
applique modes of carving. From so produced numerical models of
these objects, a three-dimensional graphical model thereof can be
displayed, and numerical coordinate tool path data files
generated.
[0126] Two-dimensional recording of surface coordinates of
preexisting physical objects can also be performed using 2-D
coordinate measuring methods and apparatus to provide
two-dimensional characteristic outlines thereof. Thereafter,
characteristic outlines so produced, can be used to generate
therefrom, three-dimensional graphical models in accordance with
the methods described hereinbefore.
OPERATION OF PREFERRED EMBODIMENT HEREOF
[0127] It is appropriate at this juncture having described
hereinbefore methods and apparatus of the present invention, to now
describe the operation of the preferred embodiment of the CAD/CAM
design and manufacturing system 1 of the present invention during
an explemary design and manufacturing cycle based on the principles
thereof.
[0128] Visualizing in ones mind a signage work to be carved on a
signboard, a designer using the design and manufacturing method
hereof, has great flexibility and numerous design tools from which
to choose. More specifically, an operator using the CPCS CAD/CAM
system hereof has several options in producing a three-dimensional
graphical model of a signage work to be carved in a signboard.
[0129] One method of designing a three-dimensional graphical model
of a signage work is to apply at the workstation 2, one of the
various computer-aided design methods described hereinbefore. For
example, using on the CAD system hereof, the method of generating
three-dimensional alphanumerical characters from corresponding
two-dimensional alphanumerical characters can produce a
three-dimensional graphical (and numerical model) model of a
composite signage work comprising such characters.
[0130] Alternatively, three-dimensional coordinate measuring
methods and apparatus can be used through the workstation 2, to
provide a three-dimensional graphical model of a physical object to
be used as a signage work which is intended to be carved in a
signboard according to principles of the present invention.
[0131] Yet, on the other hand, a designer using one of the
computer-aided design methods described hereinbefore can visualize
a signage work and applying-such design methods, produce a
three-dimensional graphical model of the signage work.
[0132] From the three-dimensional graphical model however produced,
a mathematical representation of the signage work, such as a
numerical coordinate (tool path) data file, can be generated and
provided to the CAM system 4 having carving tool 11. The material
constituting the signboard is then removed using the carving tool
11 moving under the controlled guidance of the CAM system 4, to
leave in the signboard, a three-dimensional carved pattern
corresponding to the signage work. Notably, the three-dimensional
carved pattern in the signboard will have three-dimensional
surfaces corresponding to the three-dimensional surfaces of the
three-dimensional graphical model of the signage work.
[0133] It is herein noted that during the machine carving
operation, tool change may be required according to the designed
carving program (e.g., tool path data file) which has been provided
to the Post Processor 16 of the CAM system 4. In such instances,
carving tool bits of the type illustrated in FIG. 5, can be
accessed from tool storage 26 during a carving operation, and
changed in accordance with the carving program whereafter the
carving operation can resume. Tool change can occur as often as
desired.
[0134] Also in instances where "chisel or gouge markings" formed in
the three-dimensional carved grooves are desired, an approach
employing several levels of carving processes (and thus multiple
composite carving tool paths) can be adopted and CNC programmed. In
such a multi-stage carving process, the later stages of the carving
process can include carving tool movement to create the chisel
and/or gouge markings, as to emulate the textural appearance of
such traditional hand-carved wood signs.
[0135] After a signage work has been carved into the signboard
using the computer-aided design and manufacturing method of the
present invention, finishing operations can then be performed on
the carved sign according to conventional principles and
techniques.
[0136] For example, the carved signboard can be prepared for
painting and gold leafing. In cases where the signboard is
constituted of wood, conventional wood finishing techniques can be
employed. Examples of such techniques can be found in How to Carve
Wood by Richard Butz cited hereinbefore. Thereafter, gold-leaf
material can be applied to the signboard in accordance with
techniques known in the traditional wood carving arts. Discussion
of such applicable techniques can be found in Chapter IX entitled
"Laying and Burnishing Gold" of Writing & Illuminating &
Lettering (1983) by Edward Johnston, published by Adam &
Charles Black of London, England, and by the Taplinger Publishing
Co., Inc. of New York, N.Y. In the case where vinyl or like plastic
is used as signboard constituting material, conventional
gold-leafing can be obviated, and chrome or gold spray or
deposition processes can be used. Alternatively where the signboard
is constituted of metal, electroplating processes can be used to
deposit light reflective coatings over three-dimensional carved
surfaces.
[0137] Attention is now accorded to the types of materials out of
which the signboards may be constituted. It has been discovered
that aside from woods such as for example, mahogany, pine, redwood
and cedar, other materials such as acrylic, vinyl, polycarbonate,
styrene, aluminum, brass and foam board, also provide suitable
signboard materials for practicing the method of the present
invention.
[0138] There are several parameters which should be considered
prior to carving using the design and manufacturing method of the
present invention. Specifically, as regards spindle speeds, (i.e.,
of the axially rotating carving tool 11), it has been discovered
that speeds within the range of 15,000 to 24,000 RPM have provided
excellent results when computer-carving mahogany wood. However,
when using wood, cutting directions of the axially rotating carving
tool hereof must also be considered in view of the grain of the
wood. It has been discovered that information regarding "grain" of
particular wood signboards to be carved using the methods hereof,
can be model on the CAD system and used to generate tool paths
which consider the grain of the wood signboard.
[0139] In the present invention sanding operations can be executed
using axially rotating sanding tools of appropriately configured
dimensions, which are moved in the three-dimensional carved grooves
of signage works, under the guidance of the NC programmed CAM
system hereof.
[0140] It would be within the scope and spirit of the present
invention to also provide computer-produced sternboards for boats,
yachts and the like, as well as computer-produced tombstones using
the design and manufacturing method of the present invention. In
the case of tombstones, the signboard can be a stone material such
as granite, marble, sandstone or other suitable material, and the
carving tool bit can be "diamond tipped" or made of material
appropriate for carving stone under the guidance of the CAM system
hereof.
[0141] Using the method and apparatus of the present invention,
names and patterns typically cut into tombstones by conventional
waterjet cutting, sandblasting, chiseling and routing processes can
be carved by way of an axially rotating cutting tool having at
least three-programmable axes of simultaneous movement, under the
guidance of the CAM system hereof.
[0142] It would also be within the scope and spirit of the present
invention to utilize one of laser and sandblasting principled
devices as the carving tool of the method and apparatus of the
present invention.
[0143] In the case where laser devices are used, a laser beam of
sufficient energy to burn away wood or other signboard constituting
material can be controllably moved simultaneously in at least three
programmable axes under the controlled guidance of the CAM system
hereof. Such controlled movement of laser beams can remove
signboard constituting material as to leave three-dimensional
carved patterns in the signboard, which correspond to the
three-dimensional surfaces of the three-dimensional graphical model
of the signage work to be carved therein. One example of laser
cutting techniques is illustrated in U.S. Pat. No. 4,430,548 to
Macken wherein laser apparatus and a process for cutting paper is
disclosed.
[0144] In the case where sandblasting devices are used, a focused
pressurized stream of sand or like particles to blast away wood or
other signboard constituting material, can be controllably moved
simultaneously in at least three programmable axes under the
controlled guidance of the CAM system hereof.
[0145] However, in both the laser cutting and sandblasting
processes described hereinabove, controlling the cutting depth of
the laser beam in the case of the laser cutting process, and the
sand stream in the case of the sandblasting process, is extremely
difficult. In both cases, the post processor must take into
consideration (i) the physical properties of the signboard
material, and (ii) the precise energy (i.e., heat or momentum) of
the cutting process utilized so that precise cutting depths can be
obtained.
[0146] Further modifications of the present invention herein
disclosed will occur to persons skilled in the art to which the
present invention pertains and all such modifications are deemed to
be within the scope and spirit of the present invention defined by
the appended claims.
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