Authors: YehLiang Hsu, PoEr Hsu, YungChieh Hung, YaDan Xiao (20100430)；recommend:
YehLiang Hsu (20100824).
Note: This paper is presented at the ASME 2010 International Design
Engineering Technical Conferences (IDETC), Montreal, Quebec, Canada, August
2010.
Development and application of a patentbased design around
process
Abstract
Patent
infringements have become an important issue for industries when developing
products. Designing around existing patents of competitors is a task constantly
faced by designers. New design problems, which are often a local innovation of
an existing patent, are generated during the designaround process. The rules
of patent infringement judgment present the major constraints to such design
problems, and designers may have to sacrifice performance of the product in
order not to infringe on existing patents. This research proposes a
patentbased design process by systematically integrating patent information,
the rules of patent infringement judgment, strategies of designing around
patents, and innovative design methodologies. The purpose of the process is to
generate a new design concept that is a slight variation of one of the
concerned patents but does not infringe on existing patents. The basic idea is
to consider the design structure that will avoid patent infringement before
engineering design concepts are actually generated.
In this process,
first the designer conducts standard patent analysis to identify the related
patents to be designed around. Each patent is then symbolized by a “design
matrix” converted from the technology/function matrix of the patent. A
designaround algorithm is developed to generate a new design matrix that does
not infringe on design matrices of existing patents. Then the new design matrix
is transformed back into a real engineering design using the “contradiction
matrix” in Theory of Inventive
Problem Solving (TRIZ). This design process aims to assist enterprises to enhance the
efficiency of product development, lower the possibility of patent
infringements, and increase the potential to patent results of innovation. A computerized
designaround tool for this patentbased design process is also developed. Two
designaround examples are used to demonstrate this process and the
computerized designaround tool.
Keywords: design process, design
around, patent analysis, patent infringement
1.
Introduction
Design process
plays an important role in the success of a product’s development. Systematic product design processes commonly seen in research literature
or design textbooks often start with finding a need, specification development,
conceptual design, detail design, and finally production. Such design processes
are very useful for innovative design. Innovative design methodologies such as analogy,
brain storming, and Theory of
Inventive Problem Solving (TRIZ) are often used to generate engineering design solutions.
However, the design problem constantly faced by
engineering designers across industries is how to design around existing
patents [Glazier, 1990], which
requires a completely different design approach and knowledge. This type of
design problem is often a local innovation of an existing patent. The rules of patent infringement judgment present the major constraints to
such design problems, and designers may have to sacrifice performance of the
product in order not to infringe on existing patents.
Although patent analysis has almost been a
standard process in the early stage of product development in industry, few
researches in design processes consider competition or constraints in the form
of existing patents and fully utilized the information obtained from patent
analysis. Chen and Chen [2004] integrated the systematic design process and
design patent protection mechanism to develop an adaptive design process. Zhang
and Chen [2004] presented a process based upon the extension theory and TRIZ to
design around patents and resolve conflictive problems. Chang et al. [2004]
proposed an auxiliary methodology for creative mechanism design. This methodology
is a systematic approach based on modification of existing devices for the
generation of all possible topological structures of mechanisms to avoid
existing designs that have patent protection. Hung and Hsu [2007] described an integrated
process for designing around existing patents through TRIZ.
Designing around is based on the process and rules
of patent infringement judgment to develop a design that has substantial
difference in the scope of claims of existing patents. Designing around techniques
have been discussed in many textbooks. For example, Nydegger and Richards [2000] proposed three possible strategies for designing around an existing
patent:
(1)
Reduce the number of elements
in the claims to satisfy the full elements rule.
(2)
Use the method of substitution
to make the accused subject matter different from the techniques disclosed in
the claims to prevent literal infringements.
(3)
Substantially change one of the
constitutive requirements of way/function/result to prevent infringements
according to the doctrine of equivalents.
These designing
around techniques provide a good guideline for avoiding patent infringement. Note
that each of the methods described above, reduce the number of elements,
substitution, or change one of the constitutive requirements, presents a new
design problem to be solved. Innovative design methodologies are still needed to
generate real engineering solutions for the new design problems.
This research proposes a patentbased design process
by systematically integrating patent information, rules of patent infringement judgment,
strategies of designing around patents, and innovative design methodologies. Instead of generating a completely innovative design, the purpose of
the process is to generate a new design concept that is a local variation of
one of the concerned patents but does not infringe on existing patents. The
basic idea is to consider the design structure that will avoid patent infringement
before engineering design concepts are actually generated.
Figure 1 shows the
conceptual flowchart of this patentbased design process. To start with, the
designer conducts standard patent search and analysis to identify the patents
to be designed around and to collect functions and core techniques of each
concerned patent. Each concerned patent is then symbolized by a “design matrix” converted from
the the technology/function matrix of the patent to represent its design
structure from patent point of view. This design matrix representation is
inspired by the Axiomatic Design (AD) methodology developed by Suh [2001],
which uses matrix methods to systematically analyze the transformation of
customer needs into functional requirements, design parameters, and process
variables. AD has received great attention from engineering designers in recent
years, and have been widely applied in various engineering design applications.
Cebi and Kahraman [2010] made a comprehensive literature survey on AD
principles covering 63 papers.
The design
matrices representing the patents can be manipulated mathematically. Rules of
infringement judgment and design around strategies are converted into mathematical operators applying on the design
matrices. In this research, a designaround algorithm is
developed to generate a new design matrix that does not infringe on design
matrices of concerned patents. There can be many design matrices that satisfy
the constraints. In our algorithm, the design matrix which is the smallest
variation of one of the design matrices of concerned patents to be designed
around will be chosen first. The new design represented by this design matrix
will also be a local variation of a concerned patent. Finally, TRIZ is used to transform this new design
matrix back into a real engineering design, knowing that the new design will
not infringe on the concerned patents.
The whole
process is integrated into a computerized “DesignAround Tool (DAT)”. By defining
the technology/function matrix of the patent to be designedaround in DAT, the
designer can conveniently obtain a series of design problems to be solved,
sorted by the extent of variation to the existing patent.
Figure 1. Conceptual flowchart of the patentbased
design process.
TRIZ is a
systematic approach to finding innovative solutions to technical problems which
was put forward by a
former Soviet Union scientist Altshuller. TRIZ is an available tool for design engineers to handle conflict conditions
during the innovation design problem solving process. There are several
methods in the TRIZ toolset [Altshuller, 1998]:
Ÿ Ideality
Ÿ Contradiction Matrix
Ÿ Physical Contradiction Resolution Principles
Ÿ Substance Field (SuField) Analysis
In this
research, the Contradiction Matrix is mainly used to convert the new design
matrix into an engineering design solution. However, this transformation may
fail because there may not be a feasible engineering design corresponding to
the new design matrix generated by the algorithm. Referring to Figure 1, if
TRIZ fails to generate a feasible design, the algorithm is triggered again to
generate the next design matrix which satisfies the patient infringement
constraints and is the smallest variation of one of the design matrices of the
concerned patents. Finally, one or more new design concepts are generated.
The rest of the
paper is organized as follows. In Section 2, a portable magnetic impact tool design problem, which will be used to
illustrate the patentbased design methodology throughout this paper, is
described first. Section 3 discusses
how the related patents obtained from patent analysis are symbolized using the
concept derived from Axiomatic Design. Section 4 and 5 discuss the development
of the designaround algorithm and the integration with TRIZ to generate the
real engineering design concept. The portable magnetic
impact tool design example is used again to illustrate the detailed steps of
implementation. Section 6 presents a computerized “DesignAround Tool (DAT)” based on the
innovative patentbased design process. Another
example, the designaround problem of a golf club head with weight adjustment,
is solved using DAT. Finally Section 7 concludes the paper.
2.
The portable magnetic
impact tool design problem
Portable power
tools used for drilling and fastening are expected to be relatively small and
light, yet providing high power to perform the desired functions. Figure 2
shows the major components of a portable power tool driven by an electric
motor. The rotational motion of the motor is transmitted to a chuck that holds
a tool output shaft by means of a hammer. The motor is generally small due to
restrictions imposed on the overall size and weight of the portable power
tools. Limited power of the small motor might not be enough to drive the
intended load. A hammer type of mechanism is used to generate high output
torque from a small drive.
Figure 2. Components of a portable power tool
As shown in
Figure 3, the hammer stores the rotational energy of the motor over a large
angle of rotation, for example, a half turn. Then the hammer hits the chuck to
create an impact torque over a small angle (for example 10 degrees) of rotation
of the chuck. In this type of portable power tool, loud noise is generated when
the hammer hits the chucks. To eliminate the hammering noise, some patents have
proposed the concept of a magnetic impact tool with which screws are tightened
using magnetic coupling to deliver a strike without any contact. Therefore a
tightening rotational impact force can be obtained without a collision sound.
Figure 3. Top view of a hammer type impact
generator
One successful example of a
magnetic impact tool is disclosed in U.S. Patent 6,918,449, granted to
Shinagawa et al. [2005]. As shown in Figure 4, the magnetic impact tool
comprises a magnetic hammer driven by a motor, a magnetic anvil disposed so as
to face the magnetic hammer, and an output shaft that rotates together with the
magnetic anvil. The magnetic hammer is movable with respect to the magnetic
anvil without contact.
A rotational
impact force is magnetically generated in a noncontact manner for the magnetic
anvil in conjunction with the rotation of the magnetic hammer. During the
screwtightening work, the magnetic hammer and magnetic anvil begin to rotate
together without any impact action when the load torque is initially low. When
the load torque exceeds the magnetic attraction torque, the magnetic hammer and
magnetic anvil are not synchronized anymore. Impact action can be generated,
and screw tightening and loosening work can be carried out even if a lowtorque
motor is used.
Figure 4. U.S. Patent 6,918,449
The torque
generated between the magnetic hammer and magnetic anvil can be changed by the changing
device to vary the distribution ratio of the magnetic flux from the magnetic
hammer to the magnetic anvil. As shown in Figure 4, there is a magnetic bypass
device for distributing magnetic flux between the magnetic anvil and the
magnetic hammer. There is also a changing device for changing the distribution
of magnetic flux. The changing device comprises a micromotor (25a), a worm gear (25b) and pinion gear (25d).
The pinion gear is mounted on the external peripheral surface of the bypass
device (24a). The bypass
device can be moved in a reciprocating manner in the axial direction of the
drive shaft by driving the micromotor. Thus, the distribution of magnetic flux
between the magnetic hammer and magnetic anvil can be changed. A switch for
controlling the operation of the micromotor may be provided separately.
In patent
analysis, the technology/function matrix is used to investigate which
techniques can produce the specific functions. The column of the matrix represents
the functions while the row lists the disclosed techniques. The technologies and
functions are obtained from the patent abstract lists of each concerned patent.
After standard patent search and analysis, two other related patents, JP
09,254,046 and JP 2004,291,136, which achieve the same 4 functions “tighten/loosen screw”,
“generate impact torque” and “change magnetic flux” were identified. Table 1 to
3 shows the technology/function matrices of the 3 patents to be designed
around.
Table 1. Technology/function matrix of U.S.
Patent 6,918,449
Functions
Technologies

Tighten/ loosen screw

Generate impact torque

Change magnetic flux

Motor

●

●


Magnetic hammer

●

●


Magnetic anvil

●

●


Drive shaft

●

●


Output shaft

●



Magnetic bypass device



●

Changing device



●

Table 2. Technology/function matrix of JP
09,254,046
Functions
Technologies

Tighten/ loosen screw

Generate impact torque

Change magnetic flux

Motor

●

●


Electromagnetic clutch

●

●

●

Output shaft

●



Reducer

●



Table 3. Technology/function matrix of JP
2004,291,136
Functions
Technologies

Tighten/ loosen screw

Generate impact torque

Change magnetic flux

Motor

●

●


Drive shaft

●

●


Magnetic hammer

●

●


Magnetic anvil

●

●


Output shaft

●



Gap changing means



●

3.
Design matrix representation
In this
research, each concerned patent in the technology/function matrix is symbolized by a design matrix, which
is inspired by the Axiomatic Design methodology proposed by Suh [2001].
Axiomatic design is a system design methodology using matrix method to
analyze the transformation of customer needs into functional requirements,
design parameters, and process variables. The axiomatic design approach consists of two
axioms. Axiom 1, which is called the independence axiom, deals with the
relationship between functional requirements (FRs)
and design parameters (DPs). Axiom 2, which is called the information axiom, deals with the complexity
of the design.
In this research, Axiom 1 is used for representing
each patent to be designed around. A brief introduction to Axiom 1 is given below.
Let there be m components represented by a set of
independent FRs where FR is the vector of functional requirements. DPs in the
physical domain are characterized by vector DP with n components. The design matrix representing the relationship
between FRs and DPs vectors is expressed as
_{} (1)
_{} (2)
Equation (1) is
a design equation for the design of a product, where_{} is a “design matrix” that characterizes the product design.
The components in the design matrix are either “0” or “1”.
A cell takes a “0” if varying the design parameter has no
effect on the corresponding functional requirement and
a “1” if it does.
In general,
Equation (1) may be written in terms of its elements as,
_{} (3)
where n is the number of
DPs.
In the “technology/function”
matrix in Table 1~3, the “technologies” resembles the design parameters (DPs),
and the “function” resembles the functional requirements (FRs) in Equation (3).
For example, in Table 1,
FR_{1}
= Tighten/ loosen screw
FR_{2}
= Generate impact torque
FR_{3}
= Change magnetic flux
The
corresponding DPs are as follows:
DP_{1}
= Motor
DP_{2}
= Drive shaft
DP_{3}
= Magnetic hammer
DP_{4}
= Magnetic anvil
DP_{5}
= Output shaft
DP_{6}
= Magnetic bypass device
DP_{7}
= Changing device
The
technology/function matrix in Table 1 can be expressed as
_{} (4)
where _{} is the transformation matrix which transfers
the DPs into FRs. For example, in Equation (5)
_{} (5)
The first equation above
means that “Transforming components motor, drive shaft,
magnetic hammer, magnetic anvil, and output shaft achieves function of
tightening/ loosening screw.” Similarly, the second equation above means that “Transforming
components motor, drive shaft, magnetic hammer, and
magnetic anvil achieves the function of generating impact torque”; the third
equation above means that “Transforming components magnetic bypass device and changing
device achieves the function of changing magnetic flux.”
In summary, a patent can be represented by the
following equation:
_{} (6)
or
_{} (7)
where [FR] is a column vector of the “functions” of the patent, and [DP] is a column vector of the “technologies
(components)” of the patent. Both [FR]
and [DP] are extracted directly from
the technology/function table of the patent. Matrix A is a design matrix that characterizes the patent. The components
in matrix A are 0s and 1s representing the relation between functions and
technologies. Finally row vector T
is a transformation matrix which transforms the technologies into function.
4.
The designaround algorithm
This section discusses the development
of the designaround algorithm. U.S. Patent 6,918,449 is also used to illustrate the detailed
steps of implementation of the patentbased design process.
Consider a
series of design matrices of existing patents_{}, i = 1, …, n, to be designed around. The purpose of
the designaround algorithm developed in this study is to generate a new design
matrix _{} that is similar
to one of the existing matrices_{}, but does not infringe on any of the existing design
matrices. That is, to generate _{} such that
_{} and _{} (8)
where “_{}” means “is similar to”, and “≠” means “does not infringe on”.
Figure 5 shows
the flowchart of the designaround algorithm. To start with, the designer must
identify the related patents to be designed around and to collect functions
(DPs in Equation (7)) and core techniques (FRs in Equation (7)) of each related
patent, as in standard patent analysis. Each patent is then symbolized by a “design matrix”
converted from the DPs and FRs of the patent.
After transferring
the related patents into design matrices, the designer has to assign the
priority of DPs to be designed around. The priority of DPs to be designed
around is given to those having the least influence in the design matrix, which are the DPs
having the least contribution to the FRs, and the DPs having minimal
interaction with other DPs. The influences of the DPs are represented by the
number of nonzero elements in the design matrix. To assign the priority of DPs
to be designed around, the columns and rows of the design matrix are sorted
according to the number of nonzero elements.
After the
priorities of DPs are decided, the “design around operation matrices” are
applied to the DPs which have the highest priority to be designed around. In
this research, four design around operation matrices are proposed. They are
applied in the order of “elimination” (to eliminate redundant component), “replacement”
or “integration” (to make
at least one constitutive DP substantially different), and “decomposition” (to replace a
multifunctional technological characteristic with a few separate technological
characteristics). New design matrices which do not infringe on the existing
patents and the corresponding design problems are generated. New design
problems can be identified. In the next stage, TRIZ is used to solve the new
design problems and transform the new design matrix back into a real
engineering design concept.
Figure 5. Flowchart of the design around algorithm
Equation (9) shows
the design matrix representation of U.S. Patent 6,918,449. There are 7 DPs in
this patent. To assign the priorities, the columns of design matrix A are sorted according to the number of
nonzero elements. Then the rows of design matrix A are sorted according to the number of nonzero elements. In
Equation (9), the design matrix A
remains unchanged after sorting. _{} only contributes
to one function _{}, and _{}and _{} only contribute
to one function _{}. _{} and _{} only interact
with each other, while _{} interacts with 4
other DPs (_{}, _{}, _{} and _{}) to achieve function _{}. Therefore _{} and _{} have the highest
priority to be designed around, and _{} has the second
highest priority to be designed around. _{}, _{}, _{} and _{}_{ }are
considered lastly.
_{} (9)
After the
priorities of DPs are decided, the “design around operation matrix” D is applied on the design matrix to
generate a new design matrix _{}:
_{} (10)
where _{} is called the “expansion
matrix” of A, defined as
_{} (11)
and c is the number of
expanded columns. Note that the patent represented by design matrix A is equivalent to that represented by
design matrix _{}, that is, A=_{}. For example,
_{}_{}
_{} (12)
The expansion
matrix will be needed when new DPs are introduced in the design around process.
Next, the 4 design around strategies, elimination, replacement, integration, and decomposition, are converted into different design around operation matrices.
(1)
Elimination
If one or more
components in a concerned patent are found to be redundant, they can be eliminated
directly to generate a solution with simplified components/functions. For
example, in U.S. Patent 6,918,449, in order to avoid falling into the scope of all elements rule, eliminating the
magnetic bypass device (_{}) or the changing device (_{}) can be
considered first. Equation (4) shows the design matrix
representation of U.S. Patent 6,918,449, where
A=_{} (13)
Let
D_{1}=_{} (14)
_{} (15)
Clearly _{}, because _{}_{ }has
been eliminated, and the designaround technique is successful according to the
all element rule. The new design can be expressed as
_{} (16)
_{} (17)
As shown in
Equation (17), there is a new design problem to be solved (_{}), which can be translated into:
Design Problem 1: “How to design a
transformation _{} to achieve the
function _{} (change magnetic
flux) using component _{} (changing
device)?”
The same process can be used for eliminating _{} by the following design around operation matrix:
D_{2}=_{} (18)
The new design
problem to be solved (_{}) can be translated into:
Design problem 2: “How to design a transformation
_{} to achieve the
function _{} (change magnetic
flux) using component _{} (magnetic bypass
device)?”
(2)
Replacement
“Replacement”
means that one or more components of the design matrix can be displaced by
another component(s). Replacement does not take place haphazardly but
reasonably. In U.S. Patent 6,918,449, in order to avoid falling into the scope of doctrine of equivalents, replacing the magnetic bypass device (_{}) or the changing device (_{}) can be
considered first. A new DP will be introduced in the replacement operation. Therefore
the expansion matrix of A is used:
_{} (19)
To replace DP_{6}
with DP_{8}, let
D_{3}=_{} (20)
_{} (21)
The
technological characteristics of _{}_{ }must be
different from those of _{}, so that _{}, and the designing around is successful according to the doctrine of equivalents. The new design can be expressed as
_{} (22)
_{} (23)
The new design
problem to be solved (_{}) can be translated into:
Design problem
3: “How to design a
transformation _{} and a new
component _{} to achieve the function_{} (change
magnetic flux) using component _{} (changing device)
and _{}, while the technological characteristics of _{} are different from those of _{}.”
The same process can be used for replacing _{} by the following design
around operation matrix:
D_{4}=_{} (24)
The new design
problem to be solved (_{}) can be translated into:
Design problem
4: “How to design a
transformation _{} and a new
component _{} to achieve the
function_{} (change
magnetic flux) using component _{} (magnetic bypass
device) and _{}, while the technological
characteristics of _{} are different from those of _{}.”
(3)
Integration
“Integration”
combines two or more different components, and the technological
characteristics of the resulting
design are substantially different from those of original components. For example, in U.S. Patent 6,918,449, in order to avoid patent infringement by the all elements rule, the
new product can be obtained through integration of the two technological characteristics of _{} and _{}. Again a new component will be
introduced in the integration operation, therefore the expansion
matrix of A is used:
_{} (25)
To integrate _{} and _{} into _{}, let
D_{5}_{} (26)
_{} (27)
Clearly _{}, because _{} and _{}_{ }have
been integrated into _{}, and the designaround technique is successful according to
the all element rule. The new design can be expressed as
_{} (28)
_{} (29)
The new design
problem to be solved (_{}) can be translated into:
Design problem
5: “How to design a
transformation _{} to achieve the
function _{} (change magnetic
flux) using a new component _{}, while the technological characteristics of _{} are different from those of _{} and _{}.”
(4)
Decomposition
In “decomposition”,
one major component is decomposed into several subordinate components, while the
technological characteristics of the new components are different from those of
the original components. Two or more new components are introduced and the expansion
matrix of A is used:
_{} (30)
To decomposed _{} into _{} and _{}, let
D_{6}_{} (31)
_{} (32)
The
technological characteristics of _{} and _{}_{ }must be
different from those of _{}, so that _{}, and the designing around is successful according to the all element rule. The new design can be expressed as
_{} (33)
_{} (34)
The new design
problem to be solved (_{}) can be translated into:
Design problem
6: “How to design a
transformation _{} and two new components
_{} and _{} to achieve the
function_{} (change
magnetic flux) using two new components _{} and _{}, while the technological
characteristics of _{} and _{} are different from those of _{}.”
The same process can be used for decomposing _{} into _{} and _{} by the following design
around operation matrix:
D_{7}_{} (35)
The new design
problem to be solved (_{}) can be translated into:
Design problem
7: “How to design a
transformation _{} and two new
components _{} and _{} to achieve the
function_{} (change
magnetic flux) using two new components _{} and _{}, while the technological
characteristics of _{} and _{} are different from those of _{}.”
5.
Generate real engineering
design concepts using TRIZ
After applying the 4 design around operation
matrices to the components with the highest priority to be designed around, 7
new design matrices, and therefore 7 new design problems are generated. In this section, the Contradiction Matrix and the inventive
principles of TRIZ are used to solve these new design problems.
The Contradiction Matrix in the TRIZ
theory contains 39 design parameters and 40 inventive principles for
solving related engineering design problems. As shown in Table 4, the designer
searches in 39 design parameters to find the ones matching with the functions
in the design problem, and the “inventive principles” appearing
in the corresponding bracket are the possible guidelines to generate the “transformation”
in the design problems described above.
For example, for Design Problem 5
described in the previous section, Parameter 10 (force)
is selected as the feature for achieving the function of “changing magnet flux” by _{}. In addition, it is
expected that _{} will be able to change
magnetic flux. Therefore Parameter 33 (ease of operation) is selected as the feature to not be deteriorated
in Table 4. Four inventive principles can be obtained. They are Principle 1
(segmentation), Principle 28 (Mechanical interaction substitution), Principle 3
(local quality), and Principle 25 (selfservice).
Table 4. The contradiction matrix
Undesired result
Feature to change

1

…

33

…

39

Weight of moving
object

…

Ease of operation

…

Productivity

1

Weight of moving
object






…

…






10

Force



1, 28, 3, 25



…

…






39

Productivity






After reviewing the four principles, Principle 28
was utilized to generate the new concept in the portable magnetic impact tool. In TRIZ, Principle 28 has four explanations:
a.
Replace
a mechanical system with an optical, acoustical, thermal or olfactory system.
b.
Use
an electric, magnetic or electromagnetic field to interact with an object.
c.
Replace
fields that are: stationary with mobile; fixed with changing in time; random
with structured.
d.
Use
fields in conjunction with ferromagnetic particles.
In particular, “use an electric, magnetic or
electromagnetic field to interact with an object” was used to solve Design
Problem 5. In the new design concept generated, the new
component_{}consists of four solenoids. The four
solenoids are mounted on the magnetic anvil, and the impact torque can be
changed by varying the distribution ratio of the magnetic flux by operating a switch for setting the output of the electric
current value. In this
concept, the new component_{} has already integrated the function of the changing device
and the magnetic bypass device.
The designer can
try to find solutions for other design problems utilizing the Contradiction Matrix in TRIZ. However, a good engineering design concept cannot be generated “automatically”.
It still depends on the domain knowledge and experience of the designer.
Moreover, transformation from a design matrix to an
engineering design concept may fail because there may not be a feasible design
corresponding to the new design matrix generated by the algorithm. For example, Design Problem 2 described in the
previous section is not feasible because the component _{} only performs the function “move magnetic
bypass device,” it is unable to change magnetic flux by itself.
6.
The computerized designaround
tool
The patentbased
design process is integrated into a computerized “DesignAround Tool (DAT)”.
After defining the technology/function matrix of the patent to be
designedaround in DAT, the designer can conveniently obtain a series of design
problems to be solved, sorted by the extent of variation to the existing
patent. In this section, another example, a design around problem of a golf
club head with weight adjustment, is used to illustrate the operation
of DAT.
The performance
of a golfer is greatly affected by the selection of golf clubs. The “swing
weight”, the weight distribution and the center of gravity of the golf club
head, is one of the major concerns when selecting golf clubs because the swing
weight significantly affects the driving characteristics.
Weight
adjustment mechanism is often incorporated into the design of the golf club
head, so that the golfers can customize the swing weight in different
situations. Many related patents on weight adjustment of a golf club head can
be found in a standard patent analysis. Figure 6 shows a golf putter head with
weight adjustable arrangement which is disclosed in U.S. Patent
6,348,014[2002]. According to the claims of this patent, there are 5
components, receiving holes, weight adjustable arrangement, annular locating
groove, rubber retaining ring, and golf putter head. The weight adjustable
arrangement made by aluminum alloy or magnesium alloy is fasten to the
receiving holes. The golfer can use different weight adjustable arrangements to
change the center of gravity of the golf putter heads. After a patent analysis,
this patent was identified by a golf club manufacturer as the patent to be
designed around. Table 5 is the technology/function matrix of U.S. Patent 6,348,014.
Figure 6. U.S. Patent 6,348,014
Table 5. Technology/function matrix of U.S. Patent 6,348,014
Functions
Technologies

Comprise the body

Fix the weight adjustable arrangement

Change the center of gravity

receiving holes

●

●


weight adjustable arrangement


●

●

annular locating groove


●


rubber retaining ring


●


golf putter head

●

●


As shown in
Figure 7, designer imports
the technology/function matrix into DAT (upper window
in Figure 7). DAT then starts
the designaround algorithm and outputs a series of
design problems to be solved, sorted by the extent of variation to the existing
patent (lower window in Figure 7).
Figure 7. User
interface of DAT
After reviewing the list of design problems, one problem
was identified by the golf club manufacturer as the design problem to be solved:
“How to design a transformation _{} to achieve
the function _{} (fix the weight adjustable arrangement) using a new component _{},
while the technological characteristics of _{} are different from those of _{}, _{} and _{}.”
This problem was
then solved using the Contradiction Matrix in TRIZ. In the Contradiction Matrix,
parameter 13 (stability of object) was selected as the feature for achieving the function of “fixing the weight adjustable arrangement” by _{}. In addition,
it was expected that _{} would be able to
fix the weight adjustable arrangement. Therefore Parameter 33 (convenient of use) was selected as the feature to not
being deteriorated in Table 4, in which the three inventive principles can be
obtained. They are Principle 32 (optical changes), Principle 35 (physical or
chemical properties), and Principle 30 (flexible films or membranes).
After reviewing the three principles, Principle 30
was utilized to generate the new concept in the golf
club head with weight adjustment. In TRIZ, Principle 30 has two
explanations:
a.
To
use flexible shells and thin films instead of three dimensional structures;
b.
To
isolate the object from the external environment by using flexible shells and
thin films.
In particular, “Use flexible shells and thin films
instead of three dimensional structures” was used to generate new design
concepts to the design problem presented above. In the
new design concept generated, the new component _{} consists of spiral
power spring. As shown in Figure 8, a tank in the golf club head contains the weight adjustment device comprised of an axle and the
spiral power spring. The center of gravity of the golf club head can be changed
by using a tool to rotate the axle. The spiral power spring inside becomes smaller
and can be fit into the tank or taken off the tank. Finally the golf club
manufacturer then developed the innovative design concept in Figure 8 into a
prototype as shown in Figure 9.
Figure 8. New design concept of new component _{}
Figure 9. The prototype of golf club head
7.
Conclusions
The design problem constantly faced by engineering
designers across industries is how to design around existing patents, instead
of generating a completely innovative design. Although patent analysis has
almost been a standard process in the early stage of product development in
industry, information obtained from patent analysis is often not fully utilized.
This paper
proposes a patentbased design process by systematically integrating patent
information, the rules of patent infringement judgment, strategies of designing
around patents, and innovation design methodologies. The basic idea is to
consider patent infringement before engineering design concepts are actually
generated. Design matrices are used as the mathematical representations of
patents and design around operations, such that a new design matrix that does
not infringe on design matrices of existing patents can be generated by
mathematical manipulations. New design problems are formed. Finally the
Contradiction Matrix in TRIZ, which is a perfect match to this design process,
is then used to generate a real engineering solution.
The whole
process is integrated into a computerized “DesignAround Tool (DAT)”. By defining
the technology/function matrix of the patent to be designedaround in DAT, the
designer can conveniently obtain a series of design problems to be solved,
sorted by the extent of variation to the existing patent.
This design
process aims to assist enterprises to enhance the efficiency of product
development, lower the possibility of patent infringements, and increase the
potential to patent results of innovation. From another point of view, the
enterprises can also use this process to check whether it is easy to design
around their own patents, and how to establish a complete patent portfolio
without any possible loopholes.
Reference
Altshuller, G.,
“40 principles: TRIZ Keys to Technical Innovation”, Technical Innovation
Center, MA, 1998.
Chang, W.
T., Tseng, C. H., Wu, L. L., “Creative mechanism design for a prosthetic hand,” Proceedings of the Institution of Mechanical Engineers, Part H:
Journal of Engineering in Medicine, v.218, p.451459, 2004.
Chen, A.
and Chen, R., “An
adaptive design process generated by the integration of systematic design
process and design patent protection mechanism,” INTERNATIONAL JOURNAL OF
GENERAL SYSTEMS, v.33, p.635653, 2004.
Chiu; Chih Hung,
“Golf
putter head and weight adjustable arrangement,” United States
Patent 6,348,014, 2002.
Glazier, S. C., “Patent Strategies for Business,” Law & Business Institute, 1990.
Hung, Y. C., Hsu, Y. L., “An integrated process for
designing around existing patents through TRIZ,” Proceedings of the I MECH E Part B Journal of Engineering Manufacture,
v.221, pp. 109122, 2007.
Kulak, O., Cebi, S., Kahraman, C., “Applications of
axiomatic design principles: A literature review,” Expert Systems with Applications, v.37, pp. 67056717, 2010.
Nydegger, R. and Richards, J. W., “Design Around Techniques,” in Lundberg
et al., Electronic and Software Patents, The Bureau of National Affairs,
Inc., Washington, D.C., 2000.
Shinagawa, S., Nakayama, S., Sekino, F., “Magnetic impact tool,” United States Patent 6,918,449, 2005.
Suh, N. P., “Axiomatic Design: Advances and Applications,”
New York: Oxford University
Press, 2001.
Zhang, H.
T. and Chen, J. H., “Application of extension theory and TRIZ to
innovation design,” Industrial Engineering
Journal, v.7, p.3337, 2004.