Date: 20081126
Docket: A-577-07
Citation: 2008 FCA 369
CORAM: LINDEN J.A.
RYER
J.A.
TRUDEL
J.A.
BETWEEN:
JOHN RUSSELL MCKAY
Appellant
and
WEATHERFORD CANADA LTD.,
WEATHERFORD ARTIFICIAL LIFT SYSTEMS INC.,
WEATHERFORD CANADA PARTNERSHIP
Respondents
REASONS FOR JUDGMENT
TRUDEL J.A.
[1]
This is an
appeal from a decision of Mr. Justice Campbell (the judge), 2007 FC 1233, dated
November 23, 2007, dismissing the appellant’s claim that the respondents
infringed the appellant’s patent and dismissing the respondents’ counter-claim
that the appellant’s patent was invalid for obviousness as defined in section
28.3 of the Patent Act, R.S.C. 1985, c. P-4 (the Act). The dismissal of
the counter-claim is not challenged on this appeal.
[2]
The
appellant’s Canadian Patent 2,371,155 (McKay Patent) granted on June 10, 2003
claims a method of removing stators from tubular stator housings, involving
subjecting a tubular stator housing having an interior surface to which a worn
stator is adhered by adhesive to cryogenic refrigeration until the stator
shrinks and pulls away from the interior surface of the tubular stator housing
(reasons for judgment, Appendix A, page 38). This method is said to provide an
alternative to the use of hydraulic or mechanical rams to break the bond of the
adhesive and push the worn stator (or elastomer) out of its housing (Ibid.
at page 37).
[3]
Weatherford
also uses refrigeration to remove elastomers from stator housings, but states
that the temperatures applied are not those claimed in the McKay Patent as
Weatherford subjects a stator to cooling below the glass transition temperature
of the elastomer liner rendering the liner brittle followed by the application
of significant force to chip out the brittle elastomer from the metal housing
(respondents’ memorandum of fact and law, at sub-paragraph 2(d)).
FEDERAL COURT
DECISION
[4]
The construction
of a patent claim being antecedent to the inquiry into infringement, the judge
first applied himself to that task and then moved on to the allegations of
infringement.
[5]
The embodiments
of the invention in which protection is claimed are defined in the appellant’s
patent disclosure as follows :
1. A
method of removing stators from tubular stator housings comprising:
Subjecting a
tubular stator housing having an interior surface to which a worn
elastomer stator is adhered by adhesive to cryogenic refrigeration until the
elastomer stator shrinks and pulls away from the interior surface of the
tubular metal stator housing, the temperature of the tubular metal stator
housing being gradually lowered to cryogenic levels and then gradually raised
to ambient temperature in order to have the tubular metal stator housing
and elastomer stator shrink at substantially the same rate and avoid thermal
shock.
2.
The
method as defined in Claim 1, the tubular metal stator housing being
subjected to temperatures between minus 150 degrees Celsius and minus 200
degrees Celsius (AB, Vol. 1, Tab 3 at page 42).
[emphasis added]
[6]
At the end
of the trial, the judge constructed the patent claims as follows:
[10] Therefore,
the words of Claim 1 state that patent protection is afforded to three essential
features of the invention:
(1) subjecting
a stator housing having an interior surface to which a worn elastomer is
adhered by adhesive to cryogenic refrigeration until the elastomer
shrinks and pulls away from the interior surface of the stator housing
[emphasis added],
and
to
avoid thermal shock,
(2) the
temperature of the stator housing being gradually lowered to cryogenic levels,
and
(3) then
gradually raised to ambient temperature.
…
[11] Claim
2 is a dependent claim since it specifies, as essential, “the method as defined
in Claim 1” and, thereby, includes all the essential features of Claim 1. However,
Claim 2 limits the protection of the temperature to which the stator housing is
to be subjected. Therefore, a reasonable and fair construction of Claim 2 is as
follows:
(a) subjecting
a stator housing having an interior surface to which a worn elastomer is
adhered by adhesive to cryogenic refrigeration of between minus 150 degrees
Celsius and minus 200 degrees Celsius until the elastomer shrinks and
pulls away from the interior surface of the stator housing;
and
(b) the
temperature of the stator housing being gradually lowered to the cryogenic
levels of between minus 150 degrees Celsius and minus 200 degrees Celsius and
then gradually raised to ambient temperature to avoid thermal shock (Reasons at
paragraphs 10-11) [emphasis in the original].
[7]
Based on
his construction of the claims, he dismissed the appellant’s allegations of
infringement. Hence the within appeal.
ANALYSIS
1. The Standard of review
[8]
The construction
of patent claims being a question of law (Whirlpool Corp. v. Camco Inc.,
2000 SCC 67 at paragraph 61; Canamould Extrusions Ltd. v. Driangle Inc.,
2004 FCA 63 at paragraph 3), the construction of Claim 1 and Claim 2 by the
judge is reviewable on the standard of correctness (Housen v. Nikolaisen,
2002 SCC 33 at paragraph 8).
[9]
Infringement
of a patent is a question of mixed fact and law (Whirlpool, supra at
paragraph 75; Canamould, supra at paragraph 3). The trial judge’s
interpretation and application of expert evidence and his consideration of
evidence of the respondents’ demonstrations that led him to conclude that the
patent had not been infringed will not be set aside absent a palpable and
overriding error (Housen v. Nikolaisen, supra at paragraph 36).
2. Claim Construction
[10]
The
construction of the claims turns around two major themes: cryogenic
refrigeration and thermal shock. A principal point of contention concerns the
"cryogenic refrigeration" aspect of Claims 1 and 2.
[11]
On that
aspect, the appellant agrees with the judge’s construction of Claim 1 where,
with respect to the cooling and warming essentials of Claim 1, "cryogenic
refrigeration" was found to mean a range of temperatures beginning at
-50ºC and below.
[12]
However,
McKay takes issue with the construction of Claim 2. He argues that contrary to
what the judge found, "Claim 2 does not require that the housing
temperature be reduced to between -150ºC and -200ºC, only that the housing “be
subjected to” that temperature range" (appellant’s memorandum of fact and
law, at paragraph 16).
[13]
The judge
disagreed with McKay’s construction of the cryogenic refrigeration aspect of Claims
1 and 2 because the premise upon which it was based did not appear in the words
of the claims concerned (reasons for judgment, at paragraphs 12-13).
[14]
Ultimately,
the judge opined that McKay’s argument raised an ambiguity and referred to the Detailed
Description of the Preferred Embodiment feature of the specifications where
the narrower temperature range can be found.
[15]
The
appellant further submits that the judge erred "in finding that it was an
essential element of each of the Patent Claims that the temperature of the
stator housing be lowered and then raised at a rate of 2.5ºC per minute"
(appellant’s memorandum of fact and law, at paragraph 18).
[16]
I note
that in construing the claims, more particularly the thermal shock aspect, the
judge did not incorporate this information which can also be found in the Detailed
Description of the Preferred Embodiment. As argued by the respondents, the
judge referred to this specification only as an aid in the context of assessing
infringement. We are then left with McKay’s arguments regarding cryogenic
refrigeration.
[17]
When
construing a patent claim, the task of a trial judge is to separate and to
distinguish those elements of the claim that “are
essential if the devices are to work as contemplated and claimed by the
inventor” and the non-essential elements that “may be substituted or omitted
without having a material effect on either the structure or the operation of
the invention described in the claims” in order to define the boundaries of
legal protection to which the patent is entitled (Free World Trust v.
Électro Santé Inc. et al., 2000 SCC 66 at paragraphs 15 and 20).
[18]
In construing
the patent claims, “regard may be had to the whole of the specification,
including the drawings and the disclosure…. The onus is on the patentee to show
that, to a skilled reader, a claimed feature of the invention was obviously
substitutable” (Canamould, supra at paragraphs 27-28).
If the patent holder fails to discharge the onus, “the descriptive word or
expression in the claim will be considered essential unless the context of the
claims language otherwise dictates” (Free World Trust, supra at paragraph 57).
[19]
The appellant has
failed to show how the judge’s decision on the construction of the patent
claims was in error or not made in a fair and reasonable fashion, that is:
"… in
the sense the inventor is presumed to have intended, and in a way that is
sympathetic to accomplishment of the inventor’s purpose as expressed or
implicit in the claims" (Free World Trust v. Électro Santé Inc.,
[2000] 2 S.C.R. 1024, at paragraph 51).
[20]
More
particularly, the
appellant has not shown why it was necessary to disturb the temperature range
selected by the judge. While the cryogenic refrigeration range in Claim 1 was
found to begin at -50ºC, the demonstrations presented by the appellant at trial
would lead an ordinary worker skilled in the art to inescapably conclude that
the stator housing at the bond line had to be subjected to significantly lower
temperatures in order for the patented process to work as it was intended by
the inventor (Appeal Book, Appendix 1, at pages 199, 216, and 246-247 and 280).
[21]
Having
found that the judge made no error in construing the Patent Claims, I move on
to the grounds of appeal regarding McKay’s infringement allegations.
The Infringement Allegations
[22]
The
judge agreed with the respondents that Weatherford’s process depends on a
different principle for removal of a stator than that protected by the patent.
This being said, the judge reviewed the evidence regarding each essential of
the claims, reminding himself that “the primary infringement issue is whether,
in the exercise of the principle, [Weatherford] takes each essential of the
patent” (reasons for judgment, at paragraph 34).
[23]
As
a reminder, the essential elements at issue are (1) the cryogenic refrigeration,
that is reaching a temperature cold enough to cause the stator to shrink and
pull away from the interior surface of the metal housing; (2) the temperature
of the stator housing being gradually lowered to cryogenic levels; and (3)
gradually raised to ambient temperature.
[24]
Having heard
from two experts who commented on the recorded demonstrations of the methods
used by the appellant and the respondents, respectively, and other witnesses,
the judge concluded that since the respondent do not take any of the essentials
of Claim 1, and Claim 2 is dependent on Claim 1, … the Weatherford process does
not infringe the McKay Patent.
[25]
I now turn
my attention to the judge’s foundings on the first essential element. To succeed on
the cryogenic refrigeration essential, McKay had to prove that Weatherford had
applied a temperature below -50ºC to a certain stator housing until the
elastomer shrunk and pulled away from the stator housing. (Reasons for
judgment, at paragraph 36).
[26]
To
prove the taking of the cryogenic refrigeration essential by the respondent, McKay
took support on expert evidence and technical demonstration discussed by the
judge under two main headings:
a)
The McKay demonstrations attempting to show the
temperature at which the bond is broken (reasons for judgment at paragraphs 37
and following);
and
b)
The Weatherford demonstrations to prove the
taking of the cryogenic refrigeration essential by Weatherford (reasons for
judgment at paragraphs 40 and following).
[27]
Following
the McKay demonstrations, the judge noted that "neither expert ha(d) a
verifiable rationale to support the opinion offered" (reasons for judgment
at paragraph 39) and, therefore, did not accord them sufficient weight to
prove, on a balance of probabilities, the temperature at which the elastomer
shrinks and pulls away from the stator housing.
[28]
Having
so concluded, the judge commented on the Weatherford demonstration mindful of
McKay’s construction position throughout the trial and argument that the
respondents’ application of any temperature below -50ºC, in and itself,
constitutes the taking of an essential element of the Patent.
[29]
After
a careful review of the record, I come to the conclusion that the appellant has
failed to show that the judge made a palpable and overriding error in interpreting and
applying the evidence.
[30]
There was
ample support on record allowing the judge to conclude that
"… it is
not enough to suggest that if this stator had been subjected to a certain
temperature an infringement would have occurred. Rather, there must be
evidence that it actually did occur in a specific instance on the application
of a temperature, below -50 C, to a certain stator until the certain event
occurs."
[31]
That
certain events occur when the elastomer shrinks and pulls away from the stator
housing.
[32]
Based on
the evidence, the judge was entitled to conclude that the McKay Patent teaches
separation of elastomer from metal at very cold temperatures due to
differential shrinkage whereas the respondents’ process relies on making the
elastomer brittle and then applying force to remove it from the metal housing.
[33]
Since the
judge made no palpable and overriding error in dismissing the allegations of
infringement with respect to the first essential element of Claim 1, it becomes
unnecessary for this Court to consider further arguments put forth by the
parties.
[34]
Therefore,
I would dismiss the appeal with costs.
"Johanne
Trudel"
“I
agree
A.M.
Linden J.A.”
“I
agree
C. Michael Ryer J.A.”
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