Landis On Mechanics of Patent Claim Drafting (Outline)
Landis On Mechanics of Patent Claim Drafting (Outline)
Landis On Mechanics of Patent Claim Drafting (Outline)
35 USC 112: The specification shall conclude with one or more claims
particularly pointing out and distinctly claiming the subject matter which the
applicant regards as his invention this principle dates back to the Patent Act of
1836, and predominates the practice of patent prosecution this phrase includes
two distinct requirements, but satisfying one usually satisfies the other the core
purpose of this clause is to differentiate the patent from the prior art
Omnibus claim: This claim style simply specifies a device substantially as
shown and described, or any and all features of novelty prescribed, referred to,
exemplified, or shown this style used to be very common, and is still common
in foreign patents, but is now considered non-statutory for failing to particularly
point out and distinctly claim the invention
Peripheral claiming: 35 USC 112 requires inventors to engage in peripheral
claiming by delineating the periphery of the patent as viewed against the field of
technology and prior art this is helpful for the public and competitors who wish
to avoid the patent, but can be difficult for the patentee, as it requires some
foresight about future inventions to mitigate this difficulty, the courts created
the doctrine of equivalents to allow some degree of expansion of the metes and
bounds to encompass competing inventions
Statutory classes: 35 USC 101 sets forth four main classes of patentable
inventions: process, machine, manufacture, and composition of matter
(as well as combinations and improvements thereof) nothing can be
patented unless it can be characterized under one of these four concepts this
statute is often invoked to reject patents for mathematical formulae, algorithms,
printed matter, and articles of nature e.g., no element of a process can be a
person (Cardiac Pacemakers, Inc. v. St. Jude Med., Inc. (2002): third monitoring
means for monitoring the ECG signal was held to specify a human observer, and
thus an unpatentable method) however, these classes are interpreted broadly,
manmade organisms are patentable as compositions of matter (Diamond v.
Chakrabarty), and applied software and business methods are patentable as
processes (State Street Bank & Trust Co. v. Signature Financial Group, Inc.
(1998))
Placement after specification: 35 USC 112 requires the claims to conclude the
specification this rule isnt fully enforced, but it is good form
Single sentence: 35 USC 112 requires each claim to take the form of a single
sentence, which unfortunately leads to very protracted sentences the claim block
should begin, I claim, or The invention claimed is, or something similar; each
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claim should also begin with a capital letter and end with a period (A pencil
having a fastener at one end. see Reckendorfer v. Faber (1875)) verb forms
should also match throughout the claim
Numbering and order: In design and plant patents, only one claim is permitted;
utility patents can and usually do have many claims patents with one claim
should not include numbers, but multiple claims should be numbered
consecutively MPEP 608.01(m): claims should be ordered with the broadest
claim first, and similar claims should be grouped together (a patent claiming both
a process and its product should group the claims to each concept); a horizontal
line can be used to separate different groups of claims
Numbering during prosecution: When a claim is canceled in prosecution, its
number is not reused, and the others are not renumbered claims added during
prosecution are appended to the claim set, and are given the next highest number
when the patent issues, the USPTO renumbers all claims to produce a
consecutive set if a continuation patent application is filed, the claims in the
original patent should be logically renumbered
Preamble: Every claim should have an introductory section called a preamble
indicating the statutory class of the invention and describing it as a whole
shorter preambles are preferred (Karsten Mfg. Corp. v. Cleveland Golf Co.
(2001): an improved correlated set of iron-type golf-clubs preamble was
construed to use correlated as a claim limitation)
Preamble scope: The preamble should be consistent with the scope of the actual
claim, and should be revised if the claim scope is modified the title of the
invention should be similar to the preambles of the claims, but can vary as
needed, since the title cannot be read as a claim limitation an overly broad scope
(an apparatus comprising) is poor form its important that the preamble match
the invention described in the specification: if the specification calls for a bicycle,
the claim should not specify vehicle; similarly, if the invention is useful on
bicycles or motorcycles, the claim should not specify bicycle
Preamble limitations: The preamble should not include unnecessary limitations; if
a limitation is necessary for the claim to be patentable, it should be included in the
body of the claim, perhaps in a whereby clause but if the limitation is needed
to put the rest of the claim in proper and understandable context, it can be featured
in the preamble composition of matter claims that describe a new and unnamed
material may need to include several preamble limitations just to describe it, or
may include it as a whereby clause (a composition having density w and color x,
comprising materials y and z; a composition comprising materials y and z,
whereby the composition has density w and color x) preambles with additional
nouns may make the transition ambiguous (apparatus for shaking articles
comprising do the following limitations apply to the apparatus or the
articles?); this can be clarified by re-specifying the class (apparatus for shaking
articles, the apparatus comprising)
Preambles in dependent claims: A dependent claim implicitly, if not explicitly,
includes the text of the parent claim its incorrect to specify an invention in a
dependent claim that is broader in any aspect than its parent claim (a claim to an
apparatus for shaking articles should not be referenced by a dependent claim to
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Jepson claim preambles; claim body reliance on the preamble language for
antecedent basis; preamble needed to understand elements in the claim body;
specification emphasizing additional elements as important; and apparent use of
the preamble to avoid prior art examples of prior art avoidance: claim to E. coli
cells modified to E. coli cells of improved competence during prosecution;
CAFC held this as necessary to avoid prior art, and therefore limiting, even
though the body of the claim was unchanged similarly, addition of rich in
glucosinolates considered limitation for avoiding prior art
Transition term: The word between the preamble and the claim body materially
affects the claim two most common transition terms: comprising and
consisting of these terms may be used to describe sub-elements in a claim,
and are similarly interpreted in that context
Transition term comprising: This term means including the following elements
but not excluding others; this is an open transition term, allowing, e.g., a
method claim to cover infringing methods that include additional steps
synonyms: including, having, containing, and even wherein; but these
other terms may be construed as less open than comprising (Lampi Corp. v. Am.
Power Prods., Inc. (2000)) if many of the elements comprising an invention
share a common characteristic, a competing embodiment may infringe even
though not all of the elements share that characteristic (Texas Instruments, Inc. v.
U.S. Intl Trade Commn (1993))
Consisting of: This term means including the following elements, no more and
no less (MPEP 2111.03) synonyms: composed of, constituting, and
being while presumptively closed, these terms may be open-ended if so
described in the specification a composition consisting of certain elements
may contain trace amounts of other non-functional elements, but no more than
that however, a competing product may still infringe if it adds an element that is
non-functional; e.g., a claim to a chemistry kit consisting of certain elements
but not specifying a spatula encompasses a kit that does include the spatula,
because the spatula is not a functional part of the invention (Norian Corp. v.
Stryker Corp. (2004)) consisting of is always used for Markush groups
Consisting essentially of: This slightly broader version of consisting of allows
the addition of elements that do not affect the basic and novel characteristics of
the invention (MPEP 2111.03; In re Garnero (1969)) typically used for
compositions of matter, but may also be used in methods synonym: composed
of is sometimes interpreted with this scope other hybrids exist; e.g.: consisting
prevailingly but not essentially of (U.S. Pat. No. 3,112,301)
Claim body: The body of a claim recites the elements of the claim and describes
how they cooperate structurally, physically, or functionally to form an operative
invention elements that do not cooperate in some fashion are at best an
aggregate and probably render the claim inappropriate the claim language
should be technical, not laudatory or surplus (e.g. an apparatus comprising an
iron, thus to iron clothes more effectively than before: the latter clause should be
deleted) where the invention is a single element (e.g., a pure composition), it is
simply described; but no means plus function claim can consist of a single
means or element
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Format and punctuation: Claim elements are usually specified as a list, separated
by commas or semicolons old list style: all elements specified in a singleparagraph sentence; this is still preferred for claims with two elements modern
style: multiple subparagraphs indented to offset elements (MPEP 608.01(m))
some patents feature an outline style, prefacing each claim element with (a), (b),
(c), etc.; this is usually less readable than the subparagraph style, but may be
helpful for claims that refer back to previous elements (after step (c))
Dependent claims: A dependent claim includes the whole text and limitations of
the parent claim on which it depends the infringement test of dependency: the
dependent claim shall not conceivably be infringed by anything which would not
also infringe the basic claim (MPEP 608.01(n)) a dependent claim cannot
remove any limitation of the parent claim (the device of claim 1 without element
(x)); this should be written as a new independent claim also, the dependent
claim must add either new elements or further limitations to previously specified
elements; of course, either addition renders the dependent claim narrower than its
parent claim e.g., a composition patent may include a dependent claim that
either adds an element not specified in the parent claim, or further describes
(limits) an element featured in the parent claim the advantage of dependent
claims is that they are easier to examine than a new independent claim, and if a
claim is allowed, all claims that properly depend on it are also allowed without
further examination (Ex parte Ligh (1967))
Dependent claim structure: An invention may be independently claimed with a
number of general-purpose elements, but may be optimally used with specifics
this invention should be first claimed with a broad independent claim rather
than making one dependent claim string with each narrowing one element, it
would be better to create a number of dependent claims all depending on the
independent claim and each narrowing one element also, a dependent claim
should remain consistent with the preamble of the independent claim; if the
invention has been so narrowed that the independent claim preamble is no longer
encompassed by the claim, then a new preamble may be introduced (a method of
___, as recited in claim 1, wherein), or the claim should be written as a new
independent claim the latter option is particularly desirable where the narrowing
limitation is a core feature of the preferred embodiment
Dependent claim preamble: The preamble of a dependent claim should clarify the
dependency (the apparatus of claim 1, wherein), but dependency may be
elsewhere specified (a combination comprising (x), and the subcombination of
claim 1, connected to (x))
Honeywell problem with dependent claims: A recent CAFC decision, Honeywell
Intl, Inc. v. Hamilton Sundstrand Corp. (2004), introduced the concept that when
an independent claim is canceled during prosecution, and its dependent claim is
rewritten in independent form to include all limitations from the independent
claim, this counts as a narrowing claim amendment that creates a presumption of
surrendered claim scope and bars the use of the doctrine of equivalents (citing
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (2002)) this decision was
foreshadowed by Ranbaxy Pharmaceuticals, Inc. v. Apotex, Inc. (2003), which
held that amending a claim to remove ambiguity did not operate as a Festo
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surrender, but other amendments might however, this use is only barred for
elements that were at issue in the rejection and cancellation of the parent claim;
the doctrine may still be used for elements not at issue in the parent claim and not
altered by the dependent claim this holding is odd because 35 USC 112 4
imputes independent claim limitations into every dependent claim; thus, explicitly
adding what is already implicitly part of the claim should not constitute
narrowing nevertheless, claim strategy may swing away from dependent
claiming and prefer many independent claims open questions: (1) is the doctrine
of equivalents foreclosed for elements newly added by the dependent claim? (2) if
one independent claim is canceled due to prior art pertaining to a particular
element, is the doctrine of equivalents foreclosed for the same element and
language in another claim?
Number of claims: Patent law places no limitation on the number of independent
claims in a patent application, or the number of claims that depend on an
independent claim several dependent claims of identical wording may be
included if they depend on substantively different independent claims (Ex parte
Primich (1996)) the only legal limit is that the claims must not be unduly
multiplied to claim essentially the same invention while filing and prosecution
costs scale up with more claims, the costs may be trivial compared with the
breadth of the ensuing patent
Head claim: This term describes an independent claim on which all other claims
depend this is not required or common in U.S. applications, but is more often
used in other countries
Product by process claim: A claim may depend on a parent claim in a different
patent class this enables the product by process type of claim (the product of
the process of claim 1) conversely, the parent claim may recite a product, and
the dependent claim may recite the process of making it in a particular manner
see MPEP 608.01(n) and 2173.05(f) for more examples in both cases, the
dependent claim must include all limitations of the parent claim, and it must pass
the infringement test (e.g., infringement of the product claim must be impossible
without infringing the parent process claim); thus, a product claim does not
properly depend on a process claim if it can be made by other means also, a
dependent claim that simply claims any method of making the product of a parent
claim is unallowable, in part because it is not fully enabled however, if the
separate inventions are sufficiently distinct, the examiner might issue a restriction
requirement for each invention
Dependent claim grouping: MPEP 608.01(n): A claim which depends from a
dependent claim should not be separated therefrom by any claim which does not
also depend from said dependent claim thus, dependent claim ordering is a
depth-first process while not required, it is logical and encouraged to follow this
ordering for independent claims as well (place all claims that depend on an
independent claim before the next independent claim)
Rewriting a dependent claim as an independent claim: A dependent claim should
not be rewritten by mechanically adding every limitation in every parent claim up
to the independent claim this adds many unnecessary limitations rather, the
spirit of the imputed limitations should be added, and needless limitations should
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CAFC also created a rebuttable presumption for the second point subsequent
decisions (Honeywell and Apotex) have further applied Festo to dependent claims
rewritten in independent form after the parent claim is cancelled (see above)
however, Festo does not apply to amendments made to broaden a claim, or to
clarify the claim language
Festo in practice: The best way to avoid Festo is to never amend a claim, but this
is often impossible thus, practitioners face a dilemma: a broad claim would be
very valuable if allowed, but may damage the scope of the patent if it must be
amended; the current trend continues to favor broad claims
Overview: Apparatus includes machines, devices, electrical circuits, computerrelated items, and hydraulics essentially, an apparatus is any item containing
mechanical and/or electrical parts that cooperate for a useful purpose
Example apparatus claim:
Apparatus for shaking articles, which comprises:
(a) a container for the articles;
(b) a base;
(c) a plurality of parallel legs, each leg connected pivotally at one end to
the container and the other end to the base to support the container for
oscillating movement with respect to the base; and
(d) means for oscillating the container on the legs to shake the articles.
Preamble class: The preamble shown above is typical for apparatus patents:
recites a statutory class (apparatus, or synonyms machine, device, etc.) and
a very brief purpose for context if the device has a generic name (circuit,
carburetor, lawn sprinkler, etc.), its best to use that instead of apparatus
apparatuses that achieve several purposes may be claimed: In combination, an A,
a B, and a C; this might also be appropriate when a dependent claim adds a
component or function to an element in the parent claim (inc combination, the
means for oscillating a container of claim 2, and a container)
Preamble contextual breadth: The breadth of the context should match the breadth
of the invention: a general-purpose tool claim might begin: apparatus for
performing a specific act or operation on a particular article or workpiece; a
more specialized tool might begin: apparatus for detecting discontinuities in the
insulation of an insulated wire the context can alternately be included in a
whereby clause
Preamble as limitation: As noted in Chapter 2, preambles are sometimes
considered claim limitations however, they are always considered relevant for
patentability (MPEP 2111.02) by contrast, whereby clauses are always
construed as limitations
Elements of apparatus claims: An element is a structural part of the apparatus
a workpiece or article is an item on which an apparatus works, and usually
modifies, but is not a part of the actual apparatus
Inferential claiming: One general rule is that each element should refer only to
elements previously introduced an element should not be inferentially
introduced in a claim featuring another element as its subject (e.g., a motor
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driving a cam shaft) thus, if elements A and B are attached, claiming element
A attached to element B, and element B is wrong; claiming element A, and
element B attached to element A is correct exception: the workpiece is not
introduced as an element in its own subparagraph, but is merely referenced at the
earliest convenience within another claim element a somewhat related rule is
that active verbs should be avoided: not element A is connected to element B,
which reads as instructions for building the apparatus, but element A connected
to element B, which reads as a description of the complete apparatus
Number of elements: The broadest independent claims should feature the
minimum number of elements to support patentability in the example claim
above, the container, base, legs, and oscillating means are all necessary; a more
limited claim would also include a motor, cam, and cam follower linkage it is
helpful to consider what elements an infringing device must have however,
claiming too few elements renders the claim incomplete and inoperative
Workpiece or environment element: Many apparatuses work on a particular
item, or interact with the environment in which it is used these include fuel on
which a claimed engine operates, and celestial bodies that a claimed telescope is
intended to present for observation such an element is not recited as a proper
element in its own subparagraph, but must be mentioned to make the claims
operative it might be first mentioned in the preamble (a juicer for squeezing
citrus fruit, comprising), or might be left out if the device is intended for
broader use (a juicer comprising) it is helpful to imagine what the patentee
(and competitors) will sell as the invention, and what might be included
separately (e.g., replaceable parts); this may be the difference between suing a
competitor as a direct infringer, and as merely a contributory infringer (if he sells
the actual invention, but omits workpiece/replacement parts that are included as
claim elements)
Negative limitations: MPEP 2173.05(i): there is nothing inherently ambiguous
or uncertain about a negative limitation; In re Duva (1967) approved such use
a negative limitation may be written as a halogen other than fluorine, or an
element described as noncircular or colorless however, such stark language
may preclude the doctrine of equivalents, and it may be better to use phrases like
not in excess of 10% halide Duva involved a combination of A, B, and C that
was disabled by presence of D, and was thus claimed like comprising A+B+C
and absent sufficient D to disable the combination
Support in specification and drawings: All terms and phrases used in the claims
must have clear support or antecedent basis in the description so that the
meaning of the terms in the claims may be ascertainable by reference to the
description (MPEP 2173.05(i)) of course, this also applies to negative
limitations unsupported claim terms are rejected as indefinite under 35 USC
112; the best way to avoid this result is to include the claims almost verbatim in
the specification however, elements claimed under 35 USC 112 6 can be
listed more broadly in the claims; e.g., the specification refers to a hammer, but
the claim describes means for hammering
Drawings: A drawing should be filed with an application if necessary to
understand it (Rule 81(a)) the drawings must show every feature specified in the
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claims (Rule 83(a)), but even where this is the case, the specification should also
describe them, and the claims, specification, and drawings should be consistent
Naming elements: Each element should be given a specific name in the claim, and
should be consistently referenced by that name throughout the claims and
specification these names should be affixed early in the patent drafting process,
which helps with identifying critical claim elements the exact term chosen is not
important, as long as it fairly captures the function of the element, either in its
ordinary usage or as explicitly defined in the specification however, the name
should not be chosen too narrowly; a fastening element is broader than screw
or nail because of the doctrine of claim differentiation, if one claim element is
named in a broad claim and described in more detail in a dependent claim, the
independent claim element will be more broadly interpreted also, two similar
elements should be given distinct names, like holding means and support
means; where this isnt possible, first holding means and second holding
means can be used however, the first and second adjectives merely
differentiate different elements; they do not imply any other feature, e.g.,
temporal ordering of the elements (3M Innovative Properties Co. v. Avery
Dennison Corp. (2003)) consistency is important, particularly within a chain of
dependency (dont use structural member in an independent claim, and
reference it as support member in a dependent claim) adjectives can be
dropped in later references if the shortened form is unambiguous (connecting
appendage may later be referenced appendage, presuming there is no other
appendage element); however, the adjective can never change (e.g., to tying
appendage) (Ex parte Oetiker (1992))
Intrinsic evidence: Where a term is not explicitly defined, it is given its ordinary
meaning, relying on any context found in the specification, and possibly the
prosecution history if ambiguity remains, the parties may suggest dictionaries,
encyclopedias, and learned treatises as intrinsic evidence (Texas Digital Systems,
Inc. v. Telegenic, Inc. (2002)) the previous view was that these texts were
secondary sources of intrinsic evidence, and were secondary to the apparent
meaning of the specification (Combined Systems, Inc. v. Defense Technology
Corporation of America (2003)); however, Texas Digital and other recent cases
(W.E. Hall Co. v. Atlanta Corrugating LLC (2004)) put treatises on equal footing
with the specification, and encourage their use except where they contradict the
clear meaning of the terms used in the specification (Intl Rectifier Corp. v. IXYS
Corp. (2004)) however, the text selected must be appropriate for the field of art;
a general-purpose text shouldnt be referenced for defining terms with special
meaning in the art (Vanderlande Industries Nederland B.V. v. Intl Trade Commn
(2004)) Appendix D of this treatise features many definitions common in
mechanical patents
Express definitions: A patent applicant may be his own lexicographer (MPEP
2173.01), but cannot define a term with a meaning repugnant to its usual
meaning (MPEP 2173.05(b)) the applicant should clearly state the definition in
the specification (As used in this description and in the appended claims, the
word X means Y.)
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and results are almost always permissible, but vague statements like adapted to
are indefinite of course, means for terms are given special meaning under
112 6
Overly broad functional statements: Some practitioners attempt to use functional
language to claim a result or quality rather than a functional limitation e.g., a
woolen cloth having a tendency to wear rough rather than smooth, which fails to
particularly point out and distinctly claim the material the subject of a patent
is the device or mechanical means by which the desired result is to be secured
(Knapp v. Morss (1893)) similarly invalid are the use of the motive power of
the electric or galvanic current for making or printing intelligible characters,
letters, or signs at any distance (OReilly v. Morse (1853)), a process for using
monoclonal antibodies of claim 4 to isolate and purify interferon (Ex parte
Erlich (1967)), and a liquefiable substance having a liquefication temperature
from about 40oC to about 300oC and being compatible with the ingredient in the
powdered detergent composition (Ex parte Slub (1967)) however, no clear test
of overbreadth has been offered, and this is a frequent source of litigation (In re
Echerd & Watters (1973): having sufficient flexibility and wet strength to
permit and having sufficient adhesive characteristics to firmly bond
pertaining to features that lacked novel structure but had novel function the
CAFC reversed the USPTOs rejection) broadest allowed functional claim:
said plurality of lines providing a radial separation between panels upon
deployment, creating a region of high porosity between the panels such that the
critical velocity is less than () whereby said parachute will open and thus
decelerate; this claim style was approved by the USPTO (but rejected on prior
art grounds) (In re Swinehart & Sfiligoj (1971))
Whereby: This clause is used to describe a function, operation, or result that
necessarily follows from the recited structure or method these clauses are
always relevant to the structure or method, but should not be intentionally used to
add a limitation; instead, the limitation should be built into the claim body i.e.,
the parts should describe their own connections, and the where prior art element
is by clause should be used to clarify the objective that they achieve correct: a
container for the articles, having apertured walls, the apertures of which are
smaller in size than the articles to be shaken, whereby the articles are retained in
the container as they are shaken; incorrect: an apertured container for the
articles whereby the articles are retained in the container as they are shaken
Location of functional clauses: These should be either used at the end of a claim
element description to describe the function it achieves, or at the end of a claim to
describe the function that the overall invention achieves
Means or step clauses: 35 USC 112 6: An element in a claim for a
combination may be expressed as a means or step for performing a specified
function without the recital of structure, material, or acts in support thereof, and
such claims shall be construed to cover the corresponding structure, material, or
acts described by the specification and equivalents thereof this clause has the
effects of including all equivalents for the claim element known at the time of the
invention, but excluding all equivalents developed after the time of invention
claims not written in this style are not necessary limited to that disclosed in the
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specification, but rather are defined by the language of the claims; these are
given the plain meaning of the words used the USPTO used to hold that meansplus-function style could be invoked not just by means for or step for, but by
any style that clearly shows an intent to claim an element by the function it
performs now, 112 6 is only invoked by (1) use of means for or step for,
(2) functional language following the clause, and (3) the absence of specified
structure or material to accomplish the function (this precedent only controls the
USPTO, not necessarily the CAFC; but see AMP, Inc. v. Fujitsu Microelectronics,
Inc. (1994)) if the means-plus-function language does not properly specify a
function, it is rejected as indefinite for is not necessarily required
(Unidynamics Corp. v. Automatic Prods. Intl Ltd. (1998): spring means tending
to keep the door closed sufficient to trigger 112 6; Signtech USA Ltd. v. Vutek,
Inc. (1999): ink delivery means also sufficient) structure may be specified
without barring 112 6 interpretation if it merely enables the claimed function,
but not if the structure performs the function (Medtronic, Inc. v. Advanced
Cardiovascular Sys., Inc. (2001)); on the other hand, functional language can be
added to supplement a clear structural definition without triggering 112 6
interpretation (British Telecommunications PLC v. Prodigy Communications
Corp. (2002)) even using a technical term that implies a specific structural in
the art will bar 112 6 interpretation (Greenberg v. Ethicon Endo-Surgery, Inc.
(1996): detent mechanism had a structural connotation sufficient to preclude
112 6; contrast CCS Fitness, Inc. v. Brunswick Corp. (2002), where lever
moving element was not sufficiently structural, and would not bar 112 6)
Means-plus-function interpretation: The means-plus-function limitation can cover
an infringing device element if the infringing element (1) identically performs the
function specified in the means-plus-function claim, and (2) has the identical
structure as the element specified in the specification or an equivalent thereof
the USPTO used to construe these clauses by finding any comparable structure in
the prior art, presuming it qualified as an equivalent, and shifting the burden to the
applicant to show that it wasnt; the CAFC instructed the USPTO instead to read
the means-plus-function limitation in light of the specification for structural
information and equivalent analysis this isnt construed as importing a
limitation into the claims from the specification, but merely reading the claim
language in light of the specification (Carroll Touch, Inc. v. Electro Mech. Sys.,
Inc. (1993)); nevertheless, it has this effect
Means-plus-function drafting: Given the different interpretations of 112 6 and
non-112 6, its good practice to include two independent claims, or one 112 6
independent claim and a dependent claim wherein the means for A comprises B
also, the specification should recite several examples of elements (either new
components, or parts of another component) that could be used as the claimed
means its very good practice to include one element that is both broad and
well-known in the art, e.g., stating that a means could be a microprocessor (e.g.,
a flowchart showing a black box labeled microprocessor for the means) this
might be held indefinite, so alternatively suggesting more specific means is also
recommended attention should be paid to the single means rule, barring the
use of means-plus-function language to specify an invention as a single means
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Overview: Process claims are usually easier to write than apparatus claims,
because they have fewer elements, less structural glue, and less complexity
process claims often look like recipes method and process are synonyms,
according to 35 USC 100(b) most general rules apply to methods: claims may
be of variable breadth to inventions in any art, etc. the elements of a method
claim are actions, usually those that manipulate or transform an article or
workpiece; also, diagrams are less often included than in apparatuses the claim
may consist of a single action (Ex parte Kelly & Ford (1967)) a patentable
process may be a conventional process working on a novel material, working on a
material known but not previously used in such a method, or making a known
material by a novel method; however, merely using a novel material or producing
a novel material is not by itself sufficient (In re Durden (1985)) one exception:
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Public Law 104-208 (1996) denies enforcement of patents for medical or surgical
methods against medical practitioners, as long as the method does not involve a
patented invention
Elements of method claims: Each element of a method claim is usually a verb
phrased as a gerund (reciprocating the guide, impressing a signal, separating the
components) a purpose may be included, e.g., distilling the aqueous solution to
separate the alcohol therefrom in this case, an examiner may ask for a revision
to the more positive phrase of separating by distillation; this is not necessarily
needed: these forms are identical in function, and in such cases the patentees
preference should be heeded (Ex parte Lewin (1966)), and distilling may be
construed as narrower than separating as the claimed step, thereby avoiding
prior art the claim usually begins with a preamble, which should read like:
method of performing a specified act on a particular article, the method
comprising: a claim element can be in the step-plus-function form, according
to 35 USC 112 6, and all of the same rules apply as for apparatus functional
claiming in fact, well-written step-plus-function claims can be converted to
means-plus-function claims by replacing method with apparatus and
prepending means for to each element, and vice versa
Order of steps: The elements of a method claim are usually recited in temporal
sequence where temporal ordering is intended, it is wise to make this express
(describe step two as occurring after step one, or phrase the method comprising
the following steps in the order named) if steps are simultaneously performed,
but one modifies another, the modified step should precede the modifying step
if the ordering is unstated, the claim covers the steps in any order, including
simultaneous steps (Altiris, Inc. v. Symantec Corp. (2003))
Obvious method using novel starting material or producing unobvious product:
The patentability of such methods was affirmed in In re Ochiai (1995), in which
the CAFC held that the USPTO had improperly construed In re Durden to
presume such methods per se obvious; the CAFC held that if the starting material
is truly novel, and not just slightly different from previously known starting
materials, a known process applied to the novel material could be patented,
because the subject matter as a whole (including the novel starting product) was
not obvious to one of ordinary skill in the art simultaneous with this decision,
Congress passed 35 USC 103(b), expressly authorizing patents for obvious
biotechnology processes that use or create novel biotechnology products
Claims to methods as functions of novel apparatuses: Old principle: the process
carried out by a novel machine is only patentable if it embodies its own novelty
if the disclosed machine will inherently carry out the steps of the process set
forth in the process claims regardless of whether an apparatus claim is allowed,
[and] can[not] be carried out by some machine which is not the functional
equivalent, or by hand, then it was not patentable new rule: MPEP 2173.05(v):
process or method claims are not subject to rejection solely on the ground that
they define the inherent function of a disclosed machine or apparatus (following
In re Tarczy-Hornoch (1968))
Apparatus limitations: Often a step of a method claim will involve an apparatus,
much like an apparatus claim specifying an action as an element; of course, the
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apparatus must somehow cooperate in the method, not just be aggregated with
it however, this practice is discouraged, because the apparatus limitation may
unduly limit the process claim (by using an alternative device or manual
execution) more importantly, a method claim cannot be based solely on the
structure of an apparatus (Ex parte Dammers (1961)) thus, an apparatus should
only be included where the method specifically requires its manipulation as a step
on the other hand, compositions and chemicals are often included in method
claims as products, starting materials, or transformative agents (In re Kuehl
(1973): patent for using a new catalyst in a known method of cracking gasoline)
similarly, a dependent claim should not solely add an apparatus, but it may add a
step involving an apparatus (wherein the step of rotating the barrel includes
mounting the barrel on a turntable)
Chemical processes: A process for treating a surface of a polyethylene article to
increase its receptivity to printing ink, which comprises: exposing the surface of
the article to a saturated solution of sodium dichromate in acid. (notice this claim
is to a single-step method, which is fine) this could be dependently refined as
wherein the acid is sulfuric acid) Markush grouping can be used to specify
different classes of materials in a step, specifying the use of one or more of the
groups as noted above, In re Ochiai permits patents for the use of a novel and
unobvious starting material in a known process, or the production of a novel and
unobvious product by a known process Ochiai was preceded by In re Kuehl
(1973), in which a new zeolite compound was suggested for use in a notoriously
old chemical cracking process commonly using known zeolites, because the
selection of the novel zeolite would have been unobvious
Electrical methods: Nothing special here; the only difference is that electrical
steps are specified instead of mechanical ones
Computer program or software-related methods: These inventions can be claimed
wither as a series of means comprising an apparatus, or as a number of steps
comprising a method the USPTO used to utilize specific tests for patentability
of software (e.g., the Freeman-Walter-Abele test: (1) does the claim appropraiate
an algorithm? if so, (2) does the algorithm have any physical characteristic?), but
all such tests and requirements were expressly abandoned by State Street Bank &
Trust Co. v. Signature Fin. Group, Inc. (1998)), which held algorithms patentable
as long as they solve a real problem algorithms that simply manipulate abstract
numbers are unpatentable as a non-statutory principle, law of nature, idea, or
mathematical expression of scientific truth (Gottschalk v. Benson (1972)) the
USPTO issued guidelines in 1995 for examining computer-implemented
inventions, now codified (and broadened) by MPEP 2106, which instruct the
examiner to correlate each claim element to a relevant component in the
specification
Claims for computer-implemented inventions: An algorithm may be claimed as a
novel machine, comprising a general-purpose computer in which is embedded the
novel algorithm it may also be claimed as a novel article of manufacture,
comprising computer-readable media containing the algorithm it may most
directly be claimed as a process; prior to State Street Bank, at least one physical
element was necessary, but this is no longer true nonstatutory claims include (1)
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composition of claim 1, wherein the conductive metal is selected from the group
consisting of steel,), or even to narrow the elements of a Markush group in the
parent claim
Markush group requirements: The group should be carefully selected; suggesting
halogen and chlorine prompts a double-patenting rejection for obvious
reasons, comprising cannot be used for the transition; must be consisting of
preferably, a Markush group should always be written: selected from the group
consisting of A, B, and C (note use of commas, and concluding and) MPEP
2173.05(h) requires commonality among Markush group elements for groups
of materials, the elements must to belong to a recognized physical or chemical
class or an art-recognized class for apparatus and process claims, the members
must only possess at least one property in common which is mainly responsible
for their function in the claimed relationship (ideally, the commonality should be
specified as the generic term: a resting surface selected from the group consisting
of a chair, a bench, and a stool; this can also be claimed as means for) if
commonality is violated, the examiner can raise a restriction requirement (MPEP
803.02)
Trademarks and trade names: Such terms can be used in a patent application
where they have a fixed and definite meaning, either in the art or in the
specification four cases of proper use of a trade name: ordinary practitioners can
make the trade-name product at the time the application is filed by using the
specification or literature; the product is known to ordinary practitioners and is
readily obtainable (its composition can be kept as a trade secret); or the trade
term is used in a nonessential context in the specification a reasonableness test
is usually applied to these rules in fact, the applicant may be permitted to add a
description of the composition of the trade name at a later date; this does not
count as new matter if the applicant files a statement of identity (an affidavit
that the trademark name used in the application as filed is identical to the structure
subsequently added)
Fingerprint claims: Where an applicant has produced a new composition, but
cannot explain the physical or chemical structure, the composition can be claimed
according to some novel identifying traits, like X-ray diffraction patterns,
solubility, and melting point U.S. Pat. No. 2,482,055: substances effective in
inhibiting the growth of bacteria, comprising a substance capable of forming salts
with acid, containing the elements C, H, N, Cl, and O, being very soluble in
pyridine, its crystals having a refractive index between; the applicant had
isolated this novel protein, but had no idea of its actual structure, and so claimed it
by every known physical property a very specific description is sufficient to
distinctly claim the invention (Benger Labs, Ltd. v. R.K. Laros Co. (1962))
this tactic can even reference a drawing for an essential visual property, like an
imaging spectrum (said thiostrepton having an infra spectrum substantially as
shown in the drawing (U.S. Pat. No. 2,982,689)
Coined name claims: A coined name claim attempts to claim a composition
solely by a unique name (claim 2 of U.S. Pat. No. 2,699,054 simply reads:
Tetracycline), where the named compound is thoroughly defined in the
specification, and also is already well-known in the art (Ex parte Brian (1958):
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claim to alkali metal salt of gibberellic acid rejected for using the non-art term
gibberellic, even though defined in the specification) where the method of
creating a composition is well-known but its structure is not, a coined-name claim
can be used in parallel with a fingerprint claim for redundant protection
Claims referring to drawings: MPEP 2173.05(s) allows this tactic only in
exceptional circumstances where there is no practical way to define the invention
in words and where it is more concise to incorporate by reference than duplicating
a drawing or table into the claim e.g., a three-composition alloy might specify
ranges of composition that vary in proportion to one another; this range of
compositions is difficult to claim in words, but can be handily represented as a
two-dimensional chart; thus, can be claimed: with said components restricted to
amounts according to the chart of Fig. 1 broader example: U.S. Pat. No.
3,034,806 claims a font of numerals as shown in Fig. 1; impossible to describe
such numerals in words however, this tactic requires necessity, not merely the
applicants preference (Ex parte Lewin (1966))
Use claims: Some applicants attempt to claim a process of using a known material
for a known purpose without further detail (the process of using an iron alloy as
a vehicle brake part), which is indefinite and nonstatutory the limitation is
just a statement of purpose, such as would appear in a preamble, not a novel
process a process must possess its own novelty, rather than just being a new use
of a known material in a known process in a conventional way on the other
hand, carrying out a known process using a material well-known but not obvious
to use in the process may be patentable the rule was that even if using a wellknown composition in a novel process or way can be patented as a method, it
cannot permit the patenting of the well-known material as a composition (In re
Thuau (1943): CCPA rejected composition claim for a known compound that was
newly utilized as a tanning agent) patentability is not conveyed if the material is
added in a new solvent that does not lend any other property (Ex parte Douros &
Vanderweff (1968)), or by formulating it as a tablet or capsule that lacks added
novelty (contrast In re Graige (1951) with In re Halleck (1970)) however, the
general ruling in Thuau was called into question in In re Duva (1967), which
suggested that a preamble limitation may create novelty for such a process, and
that the claim as a whole must be considered because these doctrines are not
well-settled, it is good practice to claim a material and its use in as many forms as
possible
Jepson claims for chemical inventions: A Jepson claim is a claim for an
improvement invention, claimed by stating a preamble describing the prior art, a
transition clause (wherein the improvement comprises), and a description of the
new or modified elements this style is recommended but not required; and while
no magic words are necessary, it is recommended to use the term
combination in the preamble and improvement in the transitional clause in
order to satisfy Rule 75(e) these claims are good for differentiating the prior-art
combination and the new elements, thereby avoiding old combination rejections
the preamble of a Jepson claim is always considered a limitation (Rowe v. Dror
(1997)) accordingly, Jepson claims bear the inherent danger of implicitly
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admitting the contents of the preamble to be prior art, but this is a rebuttable
presumption (MPEP 2129)
Generic and species claims: As an alternative to a Markush group, an application
can specify a genus in generic terms, and dependently refine it into several species
e.g.: an apparatus patent might specify a support and dependent claims might
refine this as legs or springs for particularly broad elements, it may be
permissible to include an intermediate subgenus layer this tactic differs from
Markush grouping by including all undisclosed options that fit within the genus;
on the other hand, a lack of commonality among species may result in a
restriction requirement (in this context, an election of species) also, each
species must have its own dependent claim, whereas the Markush grouping
specifies all options as alternatives in one claim
Combination and subcombination: A patentable combination might also have a
patented component, sometimes called a subcombination e.g., a compound
that is a good insecticide might be claimed both on its own and in combination
with other chemicals (e.g., preservatives and dyes) that form a commercially
desirable product in order to be claimed, a subcombination must feature its own
novelty; those that do not are rejected as incomplete or lacking utility
however, claiming both in the same application often leads to a restriction
requirement these can be drafted with in an apparatus for X, an apparatus
comprising Y, or in Jepson style: an improved W for an X apparatus having old
elements Y and Z, the improvement W comprising
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described with sufficient clarity, either by its target (antibody reactive with
leukocyte interferon) or its functional use (antibody that binds to human breast
adenocarcinoma cells, but not to non-cancerous human breast epithelial cells)
however, patentability of monoclonal antibodies has been limited to those
exhibiting novel specificity for a particular antigen, or those made via a
particularly inventive process (Ex parte Erlich (1986/1992) and Ex parte Sorg
(1992))
Patentability of therapeutic methods and compositions: Therapeutic claims must
be for the treatment of a specific disease or condition, and must be supported by
experimental evidence of success the CAFC has held that in vitro evidence can
be sufficient by itself (Cross v. Iizuka (1985)); however, the burden of proof of
therapeutic use within the USPTO (Ex parte Balzarini (1991): BPAI suggested
that antiviral compounds may need even clinical trials to support a patent claim)
successful testing in animals is sufficient if the animal is recognized as a good
model for the condition in humans (In re Krimmel (1961)) the USPTO limited
this rising trend by passing a new set of guidelines instructing examiners to
consider utility fulfilled by evidence of a reasonable use for public benefit and an
reasonable correlation between the pharmacological activity of a compound and
the therapeutic use; the USPTO expressly rejected the necessity of human clinical
trials, and the CAFC affirmed (In re Brana (1995))
Patentability of gene therapy methods: Gene therapy methods (both in vivo and in
vitro) are patentable under the same conditions as other biotechnology patents, but
this is an emerging field at least one inventor has attempted a broad patent on
the entire field (U.S. Pat. No. 5,399,346), but this is likely to be rejected
Goals of claim writing: The claims should cover the invention, as broadly as
possible, in light of its operative concept and objective the claims should cover
the disclosed embodiments, and all expected and unexpected equivalents, so that a
competitor cant design around the patent by making a trivial change; in essence,
any invention that embodies the inventive concept, and any invention that
achieves the same result by a similar mechanism, should be covered the only
limits on the scope of the invention should be the prior art and the formal
requirements of the USPTO
Broad claim structure: First, the invention should be claimed from as many
perspective as possible (a method invention should include apparatus claims, and
vice versa; the invention can be claimed as a set of structural or functional means,
or a hybrid; any novel component of the invention should be considered for its
own novelty; if the invention works on a material in a novel way, perhaps this can
be claimed as a submethod, or a subcombination apparatus; product-by-process
claims should be included for all methods that produce novel products; etc. all
claims should be oriented to achieving each goal of the invention each feature or
objective should be fully covered by a set of claims, possibly beginning with an
independent claim (the examiner may issue a restriction requirement, but its
worth it to try)
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Writing a broad claim: Apparatus claims should be written in mind of the most
relevant figures; this permits accurate descriptions of the components and their
interaction, and ensures that the claims cover it conversely, every essential
feature in the drawing should be present in at least one of the claims
unnecessary elements should be removed, but of course, no element that is
necessary for the operation of the stripped-down invention should be eliminated
apparatus claims should also consider the sequential operation of the overall
process, and might claim the apparatus with one means element for each step a
very well-written apparatus claim may be able to teach the operative concept to
the reader without reference to the figures
Claiming individual claim features: First, assign the element a unique name, both
to describe it in the claim and to establish antecedent basis to the specification use
of the same term (but note that the element is not limited as the specification
suggests, but only as the claim indicates) the name should be related to the
component function, but not in any particular guise (e.g., an anvil is only useful
for its surface; this element can be claimed as a surface, with the specification
suggesting the use of an anvil (in the specification, an anvil having a surface on
which the workpiece is worked) claiming the element as a means is permitted,
but overutilizing 112 6 can damage the readability of the claims next,
describe the location and role of the component in the apparatus or article,
including previously named articles with which it necessarily cooperates in
more complicated apparatuses, it may be helpful to describe the interaction
between two elements past the description of each of them (e.g., when they
cooperate with a third element discussed later in the claim) statement of
function: where a component cooperates with another to achieve a function, this
function should be stated (a motor connected with the shaft for driving the shaft
to rotate); if its not required, dont add it
Revising the claim: After all of the claims have been written, review the claim set:
remove elements unnecessary for achieving the inventors goal, especially in
independent claims (try considering how the claim would work if each element
were removed); delete dependent claims too focused on minute details; refactor
dependent claims reciting a number of limitations into a set of smaller dependent
claims; consider using a generic name for elements more specifically named,
especially for many elements named in the alternative; remove connection means
to components that have been eliminated
Alternative claim-drafting techniques: An apparatus can be claimed as a generic
set of operative elements, each subsequently defined in more detail through
dependent claims alternatively, the invention can be described as a catalog of
parts, and the practitioner can later select them for inclusion in a claim
Claiming multiple embodiments: First, draft a generic claim that covers all of the
embodiments based on their common thread, and write a broad claim with
minimal structural limitations that completely performs the invention the
specific embodiments can be differentially covered in dependent claims if one
embodiment bears features that the others do not, a separate independent claim
can be written for it; or, one generic independent claim can be mentioned, along
with subgeneric claims, one of which mentions the additional benefit and
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process as working on some kind of article for achieving a desired process also,
the purpose to be achieved by an action should be included (hammering the
workpiece for flattening it), unless the goal is obvious from the described action
note: in this kind of claim, the product or apparatus is not claimed, and the steps
should not heavily rely on the structure of either as noted, software methods are
a patentable class of subject matter, such that a series of operational steps is a
patentable process, and a general-purpose computer instructed to run the process
is a patentable apparatus dependent method claims add further limitations or to
add detail to steps more generally claimed in parent claims where one step can
be described generally or by a more specific process (separating components by
distilling them), either put the more general descriptor first, or claim them in
parent and dependent claims a step can be claimed in step-plus-function form
under 112 6, but again, the words step for should be clearly used, and the
claim should not suggest a specific process for carrying it out
Article of manufacture claims: An article is like an apparatus without moving
parts or claimable motion; it simply exists to serve its purpose (e.g., a shoe) its
elements may still be claimed in means-plus-function form (means for bringing
together the top portion edges of the shoe, like laces, zippers, or Velcro)
computer-readable media may constitute a patentable article of manufacture
Product-by-process claims: These claims are useful where the product is novel but
incapable of structural definition, or has process-related limitations its pretty
easy to write a dependent product-by-process claim referencing the process
described in the parent process claim of course, the product must be novel to be
patentable to be claimed as a product-by-process there is no clear precedent as
to whether the process is a limitation in the claim, i.e., whether the claim covers
the product as made by other processes (contrast Scripps Clinic & Research
Found. v. Genentec, Inc. (1991) (product by process claims are not limited to
product prepared by the process set forth in the claims) with Atlantic
Thermoplastics Co. v. Faytex Corp. (1992) (process terms in product-by-process
claims serve as limitations in determining infringement)) a majority of the
CAFC seems inclined toward the latter view, but it may be resolved as a split
between the two scenarios described above (difficult-to-describe substances arent
limited by the process, but products with process-specific characteristics are
limited by the process)
Jepson claims: The Jepson claim style is useful for inventions that are clearly
improvements on prior (patented) technologies a dependent Jepson claim may
reference the invention of the parent claim as an improvement in a larger prior-art
invention however, this style is rarely used today in the U.S., because its easier
for the USPTO to cobble together a 103 obviousness rejection by reducing the
threshold for combining references, as the prior art is admitted to be close and
well-known
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