COMMISSIONER'S DECISION
OBVIOUSNESS: Fuel Tank Check
A check valve utilizing a spring-biased annular diaphragm element to
bias the diaphragm against the valve seat is shown in the prior art.
A dual function form which permits reverse flow above a predetermined
pressure is allowable.
Rejection: Modified.
This decision deals with a request for review by the Commissioner
of Patents of the Examiner's Final Action dated November 12, 1974,
on application 164,955 (Class 137-60). The application was filed
on March 1, 1973, in the name of William L. Sheppard, and is en-
titled "Fluid Valves."
This application relates to a fuel tank check valve for use in
emission control systems of automobile engines. It utilizes a spring-
biased annular diaphragm element and is unsigned to prevent the
venting of gasoline fumes to the atmosphere. Two embodiments are
disclosed, one utilizing a single function form, the other a dual
function form which combines the check valve with a pressure relief
movement. The valve opens when pressure builds up to a particular
pressure in the gas tank, but remains tightly closed below that point.
In the Final Action the examiner rejected claims 1 to 3 and 21 to 34
for failing to define patentable subject matter over a cited reference,
and claims 4 to 18 for not being set forth in distinct and explicit
terrns. The reference was U.S. Patent 3,073,339 January 15, 1963, Stelzer.
In that action the examiner stated (in part):
The Stelzer patent discloses a control valve comprising
a housing haveng a passageway therethrough, a valve seat
in the said passageway, a resilient annular diaphram having
a central opening therethrough, an enlarged bead portion
about the outer perimeter of the said diaphram, a zone of in-
creased thickness in the area of the central opening, and an
intermediate portion of the said diaphram between the said bead
portion and the zone of increased thickness being relatively
thin and flexible; the said diaphram seats on the said valve
seat at the said zone of increased thickness, and a spring
means biases the said diaphram against the said valve seat.
In view of the above discussion, claims 1 to 3, 11, 12, 21, 22,
24 and 34 are refused because they fail to define a patentable
improvement thereover.
Claims 13 and 25 to 33 differ from the device disclosed by the
Stelzer patent, in that these claims utilize a flat spring to
bias the diaphram to the valve closed position, whereas, the
Stelzer patent utilizes a helical spring. Flat springs however
are well known, and it is held that a replacement of the helical
spring by a flat spring, is a mere substitution of an equivalent,
and hence not considered to be of patentable significance. An
example of flat springs of various shapes may be seen in Canadian
patents 543,678 to Maurer et al, and 502,961 to Stilwell Jr.,
and also in United States patents 3,302,662 to Webb, and 2,901,212
to Winet.
In view of the preceding discussion claims 13 and 25 to 33 are
held to be obvious to one skilled in the art, in view of the
teaching of the cited patent, and the state of the art of
springs, hence the said claims are refused because they fail to
define a patentable improvement thereover.
Claim 4 contradicts what has been claimed in claim 1, upon which
claim 4 is dependent.
In claim 1, the diaphram is biased into sealing engagement with
a valve seat; considering for example, Figure 5; the diaphram
is numbers 30, 32, 34, 36 and the seat is number 76.
In claim 4, a movable valve element is biased into sealing
engagement with the valve seat, and, the diaphram in turn is
biased into sealing engagement with the valve element; the
valve element is number 72, and the valve seat here is number 70.
From the above comparison of claims 1 and 4, it is obvious that
the seat in claim 1 is not the seat referred to in claim 4,
hence the matter in claim 4 contradicts whit has already been
established in claim 1; claim 4 is dependent upon claim 1.
Claims 5 to 18, being dependent upon claim 4, do not overcome
or clarify the above noted contradiction of claim 4 to claim 1.
In view of the above discussion, claims 4 to 18 are refused
because the said claims are not set forth in distinct and
explicit terms.
...
The relative size of the thin portion between the bead portion
at the outer perimeter of a diaphram and the zone of increased
thickness in the inner area of the said diaphram, is a matter
of selection for one in the art, and therefore is not considered
to be of patentable significance.
One in the art would decide the size of the said thin portion
depending upon requirements of such matter as flexibility,
the area to be encompassed etc; all such factors would be
taken into consideration in deciding the size and thickness
of the said thin portion.
It should be noted that the diaphram in the Stelzer patent
performs a similar task, in a similar way to the diaphram in
applicant's device; the fact that applicant's device, as claimed,
emphasizes the entire area between the bead and the zone of
increased thickness is not considered to be of patentable
significance; such area is a matter of selection for one in
the art, and selected to suit a condition.
In the response dated February 10, 1975 to the Final Action the applicant
made the following submission (in part):
Applicant also does not agree with the Examiner regarding
the previous arguments on Stelzer. The thick rib 31 which
Stelzer deliberately provides between the inner and outer por-
tions is not only a different construction than that claimed,
but would have a different function. In particular the rib
"renders the radially inner portion of the valve element 18
comparatively stiff" (column 2, lines 39 and 40). The Stelzer
diaphragm would be incapable of responding to very small
pressure differentials which occur in such applications as
automotive gas tanks.
For the Examiner to say that this difference is "a matter of
selection for one skilled in the art" is to ignore the express
purpose of the Stelzer check valve. Admittedly, mere selection
of the particular thickness of a diaphragm in an intermediate
diaphragm portion which is of uniform thickness and relatively
thin and flexible might be but a matter of choice. However, in
this case it is not merely a matter of chosing the exact thickness.
It is a question of completely reshaping the Stelzer diaphragm
from one which has a high rib 31 several times the thickness of
the relatively thin portion 33 to one in which the rib 33
completely disappears. This is not a matter of degree but a
matter of kind. Such a change, it is submitted would not be
obvious to a person skilled in this art.
To further emphasize this point, claim 1 has been further amended
to recite that the entire intermediate portion of the diaphragm is not
only thin and flexible but is of uniform thickness throughout.
The remaining claims rejected as failing to define a patentable
improvement over the cited reference are believed to define the
invention in clear and explicit terms such that the combination
defined thereby is different from the Stelzer device. For example,
claim 12, now claim 8, is further patentable over Stelzer in that
it specifically recites the circular cross-sectional shape of the
diaphragm which engages the valve seat. This is completely different
than the sharp lip of seltzer and further emphasizes the wear
advantage of our construction.
Claim 13, now claim 9, is additionally patentable over Stelzer
in that it recites the relatively flat washer-type spring,
neither shown nor suggested by Stelzer. Although flat springs
themselves may not be new, none of the cited references show a
combination of this type of spring with the diaphragm as claimed.
There are unobvious advantages to this combination, which is
more pecifically recited in claim 19. The flat spring occupies
much less space in an axial direction, contributing to compactness
of the assembly. Additionally, previous claims 21, 22, 24 and 34
(now claims 14, 15, 17 and 27) extensively define the invention
and further remove it from the teachings of Stelzer.
The Stelzer citation relates to check valves in which the valve element is
formed of resilient material. This resilient material is in the configuration
of an annular diaphragm having an enlarged integral bead portion at its
central opening passage. Spring mans are used to bias the central portion
of the diaphragm into sealing engagement with a valve seat. Claim 1 of that
patent reads:
A check valve structure comprising a housing having an annular
M ange provided with a chamber therein and an outlet nipple
communicating with such chamber, said flange having an annular free
edge portion engageable against an apertured wall of a receptacle
and provided with an annular channel, a resilient valve element
provided with a peripheral bead shaped to fit in said channel and
having a surface substantially flush with said free edge portion
of said flange and engageable against the wall of the receptacle
to form a seal between said flange and said wall, said valve
element having an axial opening therethrough and being formed at
one side surrounding such opening with an integral annular thin-
edged lip engageable against the wall of the receptacle, the
apertures in such wall being radially outwardly of said lip, an
annular reinforcing rib formed integral with said valve element
at the side thereof opposite said lip and of larger diameter than
such lip, said rib and said lip combining to form a relatively
thick annular radially inward portion of said valve element to
lend substantial stiffness thereto, said valve element between
said rib and said bead having a relatively thin highly flexible
portion to provide for free movement of said lip toward and away
from said wall, said bead being thicker than said flexible portion
of said valve element to be retained in position by said channel.
In the check valve arrangement of the present application, a spring-biased
resilient annular diaphragm is used. The diaphragm has a central opening
having an enlarged integral bead portion about the periphery which engages
the valve seat. A dual-function form uses a check valve having a pressure
relief function permitting reverse flow above a predetermined pressure
differential.
In response to the Final Action, the applicant submitted new pages 2 and
3 for the disclosure, arid cancelled claims 1 to 34 in favor of amended
claims 1 to 27. Claims 19 and 20 which were indicated as allowable in the
Final Actior are now numbered 12 and 13. There is no indication which of
the amended claims are supported by the supplementary disclosure as required
by Rule 54 of the Patent Rules, but it has been determined from the
applicant's Patent Agent that claims 7 to 27 are to be under the heading
"Claims supported by Supplementary Disclosure." Amended claim 1 reads:
A fluid valve comprising: housing means defining a passageway
therethrough; a valve seat in said passageway; resilient, annular
diaphragm means having a central opening therethrough and an
enlarged integral bead portion disposed about the outer peri-
phery thereof, said diaphragm means preventing the flow of fluid
through said passageway except through said opening, said diaphragm
means normally sealingly engaging said valve seat along a line
surrounding said opening, and being provided with a zone of
increased thickness in the area where it sealingly engages said
valve seat, the entire intermediate portion of said diaphragm means
disposed between said bead portion and said zone of increased thick-
ness being relatively thin and flexible as compared to said bead,
spring means biasing said diaphragm means against said valve seat
into sealing engagement therewith, said diaphragm means being
movable away from said valve seat to permit the flow of fluid from
one end of said passage to the other end thereof through said
opening when the pressure at said one end exceeds the pressure at said
other end.
We give our attention first to the proposed amendment to page 2 of the
disclosure. On page 2 at line 28 the applicant has added a reference to
"the seat engaging surface of the zone being devoid of a sharply convex cross-
sectional shape." This feature, however, was not disclosed in the application
as originally filed. In the drawings the diaphragm is shown as "a relatively
stiff central section 30 containing a centre passageway 32, an annular
flexible section 34 extending outwardly from central section 30, and a
peripheral sealing head section 36." The portion of the diaphragm that
constitutes the "seat engaging" area is designated by the numeral 30. As
viewed in figure 4, the cross-sectional view of this part shows several
points wherein the intersecting surface lines intersect to form a "sharp"
surface edge. There is no description or teaching of the "seat engaging
surface of the zone being devoid of a sharply convex cross-sectional shape."
This feature is only shown in the supplementary disclosure in figure 12.
Therefore the entry of the proposed amendment to the original disclosure
at page 2 can not be permitted under Section 52 of the Patent Rules.
Consequentl/ the argument that this feature is not shown in the Stelzer
patent is immaterial, as it was not part of the original disclosure nor
reasonably to be inferred from it, and cannot be the basis of a valid claim.
Hence claim 1, which contains the statement that "the seat engaging surface
of said diaphragm zone being devoid of a sharply convex cross-sectional
shape", is not supported by the original disclosure as is required by
Section 25 of the Patent Rules.
For that reason claim 1 should be refused. In addition claims 2 to 6
which depend directly or indirectly on claim 1 should be refused. As for
claims 4 to 6, however, we find that they relate to the dual function check
valve arrangement which is not found in the prior art and would be allowable
if drafted in proper independent form (present claim 4 is dependent on
rejected claim 1). This would comply with Section 57 of the Patent Rules
which requires an application to have claims supported by the principle disclosure.
The substitution of a flat spring washer to bias the diaphragm in the
applicant's device for the helical spring of the Stelzer patent has been
rejected in the Final Action as being a mere substitution of one equivalent
for another. Several patents were cited to show that the flat spring washer
is well known, including U.S. patent 2,901,212 to Winet which relates to a
valve flow control device. The purpose of the spring here is to bias the
diaphragm to the seat. Stelzer uses a helical spring, a choice also made by
the applicant in the original disclosure as filed. In the supplementary
disclosure (figure 9), the applicant selected a combination of a helical spring
and flat spring. Figure 12 of the supplementary disclosure shows the use
of a flat spring to bias the diaphragm to the seat. Therefore the choice of a
flat or a helical spring to bias the diaphragm is merely a design preference.
The applicant argues that the thick rib which Stelzer provides "between the
inner and outer portions is not only a different construction than that
claimed, but would have a different function." We note that the applicant
also uses a thick rib portion (30, fig. 4) to provide an enlarged cross sec-
tional mass at the valve seat contact area to ensure an adequate seal. Hence
the function is the sane as in the Stelzer patent.
We now consider claims 7 to 27, which fall under the heading "Claims Supported
by the Supplementary Disclosure." Of this group we note that claims 7 to 9,
14 to 17 19 to 24 and 27 depend directly or indirectly on claim 1. Since the
subject matter of rejected claim 1 could come within the provisions of
Section 53 of the Patent Rules, we will consider this group of claims when
combined with claim 1.
On considering the difference between the cited art and the invention covered
by the combination in claim 7, we find in the latter the limitations of "the
seat engaging surface of said diaphragm zone being devoid of a sharply cross
sectional shape" and "the entire portion of the diaphragm means disposed
between the head portion and zone of increased thickness being of uniform
thickness throughout." Stelzer uses a "lip 23" as the portion of the diaphragm
engaging the seat. The applicant states that the Stelzer construction would
"result in the same surface of the diaphragm repeatedly engaging and
disengaging the valve seat, resulting in much more wear than occurs with the
present invention." In viewing the Stelzer device and its contacting diaphragm
surface, we find that it does have a less round contacting surface, but we
think this is a minor difference in design, and does not amount to an inventive
difference. Until the applicant's rounded surface becomes worn in, its point
of contact will be essentially the same as Seltzer's. After both are worn
in, the point of contact in each case will be the same. Consequently there is
no inventive feature in using a circular seat cross-section as compared to
the "V" type shown in Stelzer.
Similarly the limitation that the intermediate portion of the diaphragm is
thin and flexible as well as of uniform thickness throughout is not patent-
able. In the Stelzer patent the intermediate portion which is shown as 33
in the drawings is also thin and flexible, and of uniform thickness throughout.
Stelzer states at column 3, line 13, that, the "spring 35 can be relatively
light, and this fact together with the high degree of flexibility of the
thin annular valve portion 33 permits the valve readily to unseat for the
exhaustion of air from the receptacle 16." (underlining added). A person
skilled in the art would have no problem in selecting a diaphragm to be actuated
within a specified range of pressure differentials. In our view claim 7
is not directed to a patentable advance in the art.
The features added by the remaining claims dependent on claim 1 relate to a
circular cross section seating zone for the diaphragm, and the use of a flat
washer type spring for biasing. These features do not add anything of
patentable significance, and the arguments made against refused claim 7
apply to them. We believe claims 8, 9, 14 to 17, 19 to 24 and 27 should also
be refused.
Independent claims 10, 18 and 25 which stress the spring means to bias the
diaphragm - do not cover a new or inventive combination. The argument
to refuse claim 7 also applies equally well to them. There is no doubt that
these claims show some modification over the prior art but we believe they do
not display the necessary exercise of the creative faculties of the human
mind such as to merit the distinction of invention. In Niagara Wire Weaving
Co, v Johnson Wire Works Ltd. (1939) Ex. C.R. at 273 Maclean J. stated:
"Small variations from or slight modifications of, the current standards of
construction, in an old art, rarely are indicative of invention; they are
obvious improvements resulting from experiences, and the changing requirements
of users."
The subject matter of claim 11 which relates to the dual valve function
arrangement would be allowable when drafted in proper form. As mentioned
previously claims 12 and 13 have also been indicated as being allowable.
To summarize, claims 1 to 6 should be refused for lack of support by the
disclosure. Claims 7 to 10 and 14 to 27 should be rejected as not recit-
ing a patentable advance in the art. Claims 12 and 13, and the subject
matter found in claims 4 to 6 and 11 are allowable.
G.A. Asher,
Chairman,
Patent Appeal Board.
I am in agreement with the recommendations of the Patent Appeal Board and
refuse claims 1 to 11 and 14 to 27. I will, however, accept the subject
matter in claims 4 to 6 and claim 11 if amended along the guidelines suggested.
Claims 12 and 13 are, of course, allowable. The applicant has six months
within which to amend claims 4 to 6 and 11 and to delete claims 1 to 3 and
7 to 10 and 14 to 27 or to appeal this decision under the provisions of
Section 44 of the Patent Act.
J.A. Brown,
Acting Commissioner of Patents.
Dated at Hull, Quebec
this 10th day of February, 1976
Agent for Applicant
A.E. MacRae & Co.
Box 806, Station B
Ottawa, Ont.
K1P 5T4