COMMISSIONER'S DECISION
OBVIOUS: Result Achieved Same Way As Prior Art.
Separating annular members from hollow shaft by applying heat
abstracting medium to the hollow shaft to loosen the endmost annular
member while retaining the remaining members in tight fit in the shaft
is not a patentable advance over the prior art, which above the
removal of a railway car wheel from an axle by applying heat abstract-
ing gas to contract the axle. Applying cold and/or heat medium for
fitting and removing shrink-fitting members are well known expedients.
FINAL ACTION: Affirmed.
*********************
This decision deals with a request for review by the Commissioner
of Patents of the Examiner's Final Action dated April 9, 1974,
on application 095,177 (Class 26-87) for a "Method Of And Means
For Separating Interference-Fitted Members."
Briefly the application relates to a differential expansion technique
for disassembling mating parts which fit together. A cooling
medium such as a compressed gas is applied to the inner member so
it shrinks and the parts can be separated easily.
In the prosecution terminated by the Final Action the Examiner re-
jected claims 1 to 13, 15 to 34, and 36 to 41 for lack of invention
in view of the following reference, common knowledge and expected skill:
U.S. 1,980,156 - Nov. 6, 1934 - Emrick
In the Final Action the Examiner stated (in part):
Claim 1 refers to a plurality of side-by-side outer
"annular" members of which only the "endmost" member is
to be removed, hence the cooling and shrinking is
performed "only in the area" of this endmost member,
This selective cooling is shown in figure 8 of the
reference. The wheels of figure 8 are not in the "side-
by-side" relation disclosed by applicant, however, the
shrinkage is limited to the area of only one wheel which
will ensure that the other retains its interference fit
and will conserve the cooling gas by not cooling other
areas where the fit is to be retained. The nearness
of the side-by-side outer members is only a matter of
degree which necessitates greater or lesser care in
application of the cooling gas.
Although the reference does not show the cooling gas
directed to the inside of the wheel-and-axle assembly of
figure 8, it is held to be obvious to one skilled in the
art to do so when access to the inside of the inner
member is available. It is particularly obvious in view
of figures 5, 6 and 7 wherein a nozzle is inserted into
the interior of a hollow member.
Further evidence of the lack of inventive ingenuity is
apparent in consideration of figure 5. The outer member
is illustrated as a unitary body but it is readily apparent
that it could be an assembly of aligned parts from which
the hollow inner member is to be extracted. In operation
of this embodiment, an endmost member would be removed
by pulling it off the inner member in the manner described
as the normal operation of the device rather than by use
of the hammer member which would require relative movement
of the inner member and all outer members.
...
Regarding applicant's arguments against rejection of the
above-mentioned claims, the arguments are not well founded.
Applicant has not taken into account the fact that the
rejections are based on lack of invention over the
reference in view of common general knowledge and expected
skill. The rejections were not based upon "anticipation" nor need
they be. A showing of the absence of inventive ingenuity,
sufficiently meritorious to warrant patent protection, is also
a valid basis for the rejection of claims.
It is not required that "the prior art itself ... provide
a teaching that would render a claimed subject matter
obvious". If the distinction over the prior art is well-
known in related arts or is obvious to one exercising ordinary
skill in the art, there is no requirement to show anticipation.
When chain hoists, conveyors, flame rings and thermocouples
are so well known as to fall into the realm of common general
knowledge they may not be relied upon to provide patentable
distinction over any reference in a field in which such devices
are commonly employed unless they are employed in a new and
inventive manner which is not the case here. It is not required
that all these features be "found in the references ".
The reference to "self serving statements" of the examiner
is presumed to refer to the examiner's contention that, the
features not specifically disclosed in the cited reference,
but which he states to be of common knowledge or of expected skill,
are merely the opinion of the examiner. The devices referred to
above are well known. They constitute part of the prior art and
it is not the "mere opinion" of the examiner that such devices
are well known in the art. Applicant may see such devices as the
above-mentioned chain hoists, conveyors, flame rings and
theremocouples in many laboratories, heat-treating specialty
shops and machinery-manufacturing facilities. They are
of such common knowledge that the may be cited with a
specific reference as an acceptable alternative to a
single reference of "prior art which provides an antici-
pation" of the invention. Judicial decisions have
affirmed the validity of rejections based on prior art
and evidence of common knowledge to show lack of
ingenuity and lack of patentable improvement in the art.
The Applicant in his response dated July 9, 1974 to the Final Action
stated (in part):
The Emrick patent does not teach or suggest applicant's
invention as claimed. The best that may be inferred from
the Emrick reference is that the shaft in Fig. 8 may have
a wheel at each opposite end. Emrick was not faced with the
problem, and does not suggest how to solve the problem,
which the applicant has solved, for the removal of side-by-
side interference-fitted annular members, such as depicted in Fig.
1 of the applicant's drawings. In other words, what Emrick has is a
member at one end of a shaft and another member at the opposite
end of a shaft and that is the best that can be inferred from
Emrick. It should be noted that in Emrick it is even suggested
that merely applying the chilling tool head to the outer end
of the shaft may not be sufficient to remove the wheel and that,
therefore, the additional tool 72 of that reference be applied
to the shaft at the inner side of the wheel. In addition, Emrick
must take precaution to avoid chilling the wheel while chilling
head and the wheel. This is a necessarily slow and cumbersome
method of removing wheels from the shaft.
...
Claim 1 and claims 2-12 dependent therefrom are believed to be
patentably distinguished because the Emrick reference and no
other reference of which applicant is aware has my showing
or suggestion of an elongated hollow metal carrying member
with a plurality of shorter annular metal members interference-
fitted in side-by-side relation on the outer perimeter of the
elongated member. The Emrick reference does not teach or
suggest how to selectively remove the interference-fitted members
one at a time from an end of the member while retaining the
remaining members interference-fitted thereon. Applicant
accomplishes this, according to claim 1, by chilling and shrink-
ing selectively only the area of the elongated member encom-
passed by the endmost of the annular members by application of
heat-abstracting medium to the area at the inside of the
elongated member whereby to effect loosening of the endmost
member from the elongated member while retaining the remaining
of the annular members on the elongated member by virtue of
the interference-fit.
The Examiner admits that the reference does not show the cooling
gas directed to the inside of the elongated member on which
the other members are fitted. Contrary to what the Examiner says,
this is not obvious to one skilled in the art because the
art does not teach it. It is respectfully submitted that
the art can only know what has been taught the art. The reference
applied to the claim does not teach the method. Accordingly, the
method must be presumed to be new and the claim should be allowed.
Of interest in this case is the rationale of the Supreme Court
in The Commissioner of Patents v. Farbwerke Hoechst, 25 Fox Pat.
C. 99 (1964) at 107 where it stated:
With respect, the judgment of this Court did not proceed
on the narrow ground that novelty and utility are the
only attributes of patentability. The judgment of this
Court affirmed the judgment of the Exchequer Court for
reasons common to both judgments, namely, an adoption of
the principles stated by Jenkins J. in IN RE MAY and
BAKER LTD. and CIBA LIMITED (1948), 65 R.P.C. and
as far as I can see, until the question was raised in the
reasons delivered in the Exchequer Court no one ever
doubted the principle that invention is an essential
attribute of patentability. In any case, in this Court,
as far as I know, wherever the question has been
material the judgments have always so held.
This application relates to a method and means for separating side-
by-side annular metal members from a hollow metal carrying shaft
about which the annular metal members are carried in interference
fit. A tube having an end nozzle is inserted into the axial bore
of the carrying shaft and is capable of movement relative to the shaft.
When heat-abstracting gas such as liquid nitrogen is supplied to the
tube, the carrying shaft shrinks in the vicinity of the nozzle thereby
enabling separation of the annular member at that location. Separation
may be expedited by provision of heating means to the annular member.
The Emrick patent discloses means for seating or separating interfer-
ence fitted members by contracting the inner member by using a heat
abstracting gas thereon. In one example removal of a railway car wheel
from the axle is shown wherein the heat abstracting gas is applied to
the exterior of the outer axle portion through a socket head adapted
to fit over it. Another embodiment shows the means for the fitting or
removing of a tubular bushing in a bore end; this embodiment also shows
the use of the heat abstracting medium within the bushing bore. Claim
1 of this reference reads:
A method of separating a part from a tight encircling seat,
which consists in conducting a highly expansible refriger-
ant fluid under pressure to the part, permitting the
refrigerant to expand against the part so as to chill and
shrink the same, and withdrawing the part from the seat.
What we must consider is whether the applicant has made a patentable
advance in the art in view of the Emrick patent, common knowledge
and expected skill. It is assumed that by "common knowledge" the ex-
aminer is referring to "common general knowledge" of those skilled
in the art.
It is important to note that the "basic idea or principle" of shrink-
ing an inner member to separate interference fitted members is shown
in the citation. The disclosure on page 1, column 2, starting at
line 68, reads:
A specific object of my invention is to use as the
refrigerating agent a highly expansible fluid maintained
as a liquid under pressure so that the fluid can be
conveyed by its own pressure to the point of application
with little if any, expansion and consequently little
absorption of heat, and then to liberate the fluid at
the desired point so that by its rapid expansion it will
absorb a large volume of heat and will cause instant
chilling and contraction of the object with which it
contacts.
Emrick, on page 1 of the disclosure beginning at line 24, also dis-
cussed what was known in the art:
Occasionally, parts that have been joined by shrink fitting
or have rusted fast, are separated by heating the outer
member so that it will release its hold on the inner member
.... Sometimes this differential expansion is accentuated
by applying water or ice to the inner member to carry
off the heat conducted therein from the outer member and
thus prevent it from expanding.
Therefore in order for the applicant to obtain a patent he must show
an inventive application of this known "idea or concept."
Applicant argues that the Emrick reference does not show "an elongated
hollow metal carrying member with a plurality of shorter annular metal
members interference-fitted in side-by-side relation on the outer
perimeter of the elongated member." He adds that Emrick does not
teach how to selectively remove the interference-fitted members one
at a time from the end of the member while retaining the remaining
annular member in position.
While it is true that Emrick does not disclose the removal of a plural-
ity of shorter annular metal members in side-by-side relation from an
elongated shaft, he does show the removal of a railway car wheel
from an axle and a bushing from the bore of a tool. In the latter in-
stance a charge of "carbon dioxide is introduced into the bushing
through the tool head, so as to cause contraction of the bushing."
The nearness of the side-by-side outer members in our view is only a
matter of degree which necessitates greater or lesser care in the
application of cooling gas.
The applicant uses a nozzle in the bore of the retaining shaft to
direct his coolant at a specific location such as adjacent the endmost
annular outer member. By contrast Emrick states that in order "to
separate parts that are tightly fitted one within the other I apply a
refrigerating agent to the inner member to shrink the same and loosen
the joint between the two members." (see top of page l, column 2) It is an
expected step to direct coolant in the area of the endmost annular
member as it must be removed prior to the removal of any subsequent
member. It is also expected that the remaining annular members will be
retained in position due to the localized effect of the coolant in a
manner similar to Emrick's rail wheel.
The applicant's device is specific to internal bore cooling. Emrick
also discloses this type of cooling and "it is particularly adapted for
the insertion of long liners or bushings into sockets or bores. This
tool also involves a somewhat different principle of operation. In
the tool described above a large part of the expansion of gas takes
place within the tool head ...." (See 3rd para., page 3, of the
disclosure) In other words the "inner member" is contracted by "CO2
coolant means" using a suitable tool comprising flutes and ports to
direct the coolant to the interior of the bore.
It was argued that the "Emrick's patent does not teach or suggest
applicant's invention as claimed" since he was not faced with the problem
that the applicant has solved. This application does show means for
maintaining the elongated hollow carrying member in vertical suspension
by attaching a holding plate with eye bolts having an attached chain
supported by a hook. In addition it also shows the use of a movable
platform to change the vertical position of the coolant supply tank
which in turn moves the attached nozzle arrangement within the bore
of the elongated carrying member. To vertically suspend the shaft,
or move the nozzle axially in the shaft bore, does not involve the use
of creative skills, but only the normal skills of a person in this
art. There are other obvious arrangements which achieve the same result
i.e. moving the shaft and maintaining the nozzle and heating ring
stationary, which would not be considered patentable.
Of interest, attention is directed to United States Patent 2,839,143,
dated June 17, 1958, which is of record in the prosecution of the
application. This patent relates to improved methods and apparatus
for disconnecting a selected joint of a string of pipe or tubing.
The patent is particularly concerned with a method in which the tempera-
ture change is effected by cooling a portion of the pipe or by cooling
one portion of the joint and heating another portion. It is observed
that the disconnecting procedure is carried out while the pipe
structure is in the vertical position, and the cooling or refrigerating
unit (containing CO2) is lowered to the desired location on the
inside of the pipe.
We now consider the claims. Claim 1 reads:
A method of separating from an elongated hollow metal
carrying member a selected one of a plurality of shorter
annular metal members interference-fitted in side by side
relation on the outer perimeter of the elongated member,
comprising: effecting chilling and shrinking of said
elongated member selectively in only the area thereof
encompassed by the endmost of said annular members by applica-
tion of heat abstracting medium to said area at the inside
of the elongated member, whereby to effect loosening of
the endmost member from the elongated member; maintaining
the interference fit of the remaining of said annular members
in place on the outer perimeter of the elongated member;
and separating the loosened endmost member from the elongated
member, while retaining the remaining of the annular members
on the elongated member by virtue of said interference fit.
Claim 1 is therefore basically directed to the method of separating a
selected member of a plurality of shorter annular metal members which
are interference fitted in side-by-side relation on the outer perimeter
of an elongated carrying member by using heat-abstracting gas within
a selected bore location of the carrying member. This claim also
specifies that the remaining annular members are maintained at their
location by virtue of an interference fit.
By contrast Emrick, as previously stated, discloses the disassembly of
various devices having inner and outer members held together by an
interference fit,by applying a cooling agent, such as liquified carbon
dioxide, to the inner member to cause shrinkage of the inner member
to prevent it from expanding. By using liquified carbon dioxide "at
any desired point," Emrick was able to dispense with the "application
of heat." Prior general knowledge then includes heating and cooling of
the outer and inner members, plus Emrick's superior cooling technique,
which could obviously be used with or without the application of heat
to the outer member.
The selective application of a coolant within the bore of a shaft to
shrink it and thereby release the outer member merely applies the principle taught
by the Emrick patent. Furthermore, there is no patentable significance
in the means of retaining the remaining outer member in their respect-
ive position, as the cooling gas shrinks the elongated shaft in
immediate area of the nozzle and does not significantly effect any
other portion of the shaft. Consequently the interference fit of the
remaining members is not disturbed. The claim does recite that the
method is for use with interference-fitted members having a plurality
of side-by-side outer members. It is clear, however, that one skilled
in the art would have no difficulty in applying the principle used
by Emrick to such an assembly. In our view, therefore, claim 1 does
not disclose a patentable advance in the art.
Claims 2 and 3 which depend on claim l relate to suspension, transport
and nozzle arrangements, which limitations are not patentably significant.
Claims 4, 5 and 6 depend directly or indirectly on claim 1, and
include a heating ring to heat the outer annular member to enhance
separation.
Emrick (as quoted above) in discussing the prior art, stated it was
previously known that "parts that have been formed by shrink fitting
or have rusted fast are separated by heating the outer member...."
He also noted that sometimes this differential expansion is accentuated
by applying coolant to the inner member to carry off the heat conducted
therein. Later Emrick says, "My invention has for an object to over-
come the difficulties and disadvantages above enumerated by dispersing
with the application of heat...."
The principle therefore of simultaneous use of heat and coolant is
discussed in the citation, and these claims do not disclose any new or
unexpected result.
Claims 7 to 12, which depend directly or indirectly to claim l, add
limitations, such as moving and aligning the nozzle in the bore and
transporting the separated member. These limitations, however, are
not patentably significant. Independent method claims 13 and 15 which
detail the removal procedure of the lower member, in addition to
effecting a temperature differential, are in the same category as re-
fused claim 1.
Claims 16 to 21 which depend directly or indirectly on claim 15 introduce
limitations such as heating, transporting and separating. All the
limitations have been discussed in claims 1 to 12 and these remarks are
applicable to claims 16 to 21.
Claims 22 to 34, 36 to 41, which are for an apparatus to carry out the
method of the previously discussed claims, are substantially the same
as the previously rejected method claims, since they are couched in terms
of apparatus. Accordingly our comments in respect of claims 1 to 13
and 15 to 21 apply equally to claims 22 to 34 and 36 to 41.
The Board is mindful that when assessing an alleged invention the combina-
tion of a claim as a whole must be considered. In our view however,
even considering the combination to be novel it lacks the prerequisite
of inventive ingenuity. No new result has been achieved, nor a result
which can be considered to have flowed from an inventive step.
The applicant argues that "all the Patent Act requires is that the
presented process or machine be new and useful," and there is no requirement
for inventive ingenuity as called for by the examiner. The Patent Office,
supervised by the Court, does examine for inventiveness, wherein the
necessary patentable attributes are novelty, utility and inventive ingenuity
(Vide, Commissioner of Patents v Farbwerke, supra). In our view the claims
in question may possess novelty but they lack the prerequisite of
inventive ingenuity.
It must be kept in mind that while it is important to encourage in-
ventions because of their desirable influence upon trade and
manufacture, yet it is equally important that manufacturers or traders
of the public generally should not be hampered by the granting of
patents where there has been no exercise of the inventive faculty.
We are satisfied that the rejected claims do not represent a patentable
advance in the art. The applicant has achieved a result in substantial-
ly the same manner as taught by the prior art. The Board recommends
that the decision of the examiner to refuse claims 1 to 13, 15 to 34
and 36 to 41 be affirmed.
J.F. Hughes,
Assistant Chairman,
Patent Appeal Board.
I concur with the findings of the Patent Appeal Board, and refuse to
grant a patent on claims 1 to 13, 15 to 34 and 36 to 41. The applicant
has six months within which to cancel the refused claims or appeal
this decision under the provision of Section 44 of the Patent Act.
Decision accordingly,
A.M. Laidlaw,
Commissioner of Patents.
Dated at Hull, Quebec
this 24th, day of
March, 1975.
Agent for Applicant
Smart & Biggar,
Ottawa,Ontario