COMMISSIONER'S DECISION
Section 36(2) Claims not defining the invention: Shaft Seal for Rankine
Cycle Engine
The claims were refused for failing to include all the necessary elements of
the invention At the Hearing the applicant proposed amendments which overcame
the rejection.
Rejection modified.
The Final Rejection of application number 143170 (C1. 277/20.1) of
Thomas LeFeuvre et al, assigned to the Thermo Electron Corporation,
was referred to the Patent Appeal Board for consideration. A Hearing
was conducted on March 16, 1977, at which Mr. W.D. Parks and Mr. J. Neal
represented the applicant.
The invention is a shaft seal for Rankine cycle engines. The examiner
had made two objections related to Section 38 (Division) and to claim
dependency, both of which were overcome by amendments proposed with
the response of December 24, 1975. While the remaining objection
brought in the question of obviousness in view of certain prior art,
the main thrust of the objection was that the proposed claims failed
to specify that the pressure of the buffer fluid is constantly adjusted
automatically to prevent both egress and ingress of contaminants and oil
past the shaft seal.
At the commencement of the Hearing Mr. Parks stated that he wished to
propose another amendment which he believed would fully overcome the
rejection. He explained that the nature of the rejection had not been
fully appreciated until he and Mr. Neil were preparing for the Hearing,
and they were quite willing to make an additional amendment which he
believed would satisfy both the examiner and the Board. The new claim 1
which he proposed is as follows:
A Rankine cycle system comprising:
(a) an expander having a casing part;
(b) a rotary shaft extending from said casing part into [the]
atmosphere, the pressure in said casing part rising above
atmospheric pressure during certain conditions and dropping
below atmospheric pressure during certain other conditions;
(c) a first sealing means mounted on said shaft in fixed,
fluid tight relationship and having first and second sealing
surface areas surrounding said shaft;
(d) second sealing means mounted in fixed, fluid tight
relationship to said casing part and having first and second
sealing surface areas in sealing engagement with said first
and second sealing surface areas, respectively, of said first
sealing means;
(e) means forming a buffer fluid compartment in communication
with said first and second sealing means at their points of
engagement for maintaining a supply of buffer fluid at
said points of engagement; and
(f) means responsive to both the pressure in said casing part
and the atmospheric pressure for constantly applying pressure
to buffer fluid within said compartment which at least equals
the greater of either the pressure in said casing part or
the atmospheric pressure, during all conditions, to thereby
eliminate the tendency of material to pass along said shaft
from said casing part into said atmosphere and from said
atmosphere into said casing part.
The portion of the claim underlined is the addition which he felt would
overcome the rejection.
The examiner and the Board reviewed the proposed amendment at the
Hearing, and found that it was to be satisfactory. Since the remaining
claims are dependent on claim 1, they too will be acceptable.
The Board consequently recommends that the proposed amendment be accepted,
and the application returned to the examiner to resume prosecution.
Mr. Parks stated that he would also like to reintroduce some of the
claims previously cancelled, as the proposed amendment would, in his
view, also overcome some of the earlier reasons for applying Section 38.
We are satisfied that that is a matter which should be considered by the
examiner when examination is resurned.
It is regrettable that Mr. Parks had not come forward with his proposals
before the Hearing. However, an agent's lot is not always easy, and
we are content that a resolution satisfactory to all was reached even
at this late stage.
Gordon Asher
Chairman
Patent Appeal Board
Having considered the amendment proposed by the applicant, I direct
that it be entered, and prosecution be resumed.
J.H.A. Gariepy
Commissioner of Patents
Dated at Hull, Quebec
this 18th day of March, 1977
Agent for Applicant
A.E. MacRae & Co.
Box 806, Station B
Ottawa, Ont.
K1P 5T4