COMMISSIONER'S DECISION
OBVIOUSNESS: Fibre & Cement Support for Underground Tunnels
Spraying a fibre-reinforced cementitious mixture on the surface of an under-
ground tunnel is not patentable over the prior art, which shows spraying
block walls with the same mixture.
Final Action: Affirmed.
This decision deals with a request for review by the Commissioner of
Patents of the Examiner's Final Action dated April 29, 1975, on
application 152,834 (Class 61-65). The application was filed on Septem-
ber 28, 1972, in the name of James A. Harvey, and is entitled "Method Of
Supporting The Roof and Walls Of An Underground Tunnel." The Patent Appeal
Board conducted a Hearing on November 17, 1976, at which Mr. G.W. Partington
represented the applicant.
This application relates to a method of supporting the roof and walls of
an underground tunnel by spraying a fibre-reinforced cementitious mixture
on the surface. The cementitious mixture consists of any Portland Cement
product or any High Alumina Cement product in combition with sand, gravel
and ground materials. The fibre reinforcement may consist of one inch metal
strands, or fibres such as alkaline a resistant glass or plastic materials,
for example, polypropylene. Figure 1 shown below is representativa of the
applicant's arrangement.
(see formula I)
Reference numerals 2 and 3 represent the roof and walls of the underground
tunnel while 4 is a layer of hardened fibre-reinforced cementitious mixture.
In the Final Action the examiner refused the application for lack of patent-
able subject matter in view of the following patents.
British Patent
1,042,606 Sept. 14, 1966 Winn
United States Patent
3,381,479 Nov. 7, 1968 Curzio
The Winn patent relates to the dispensing and use of a fibrous material for
spraying as a cementitious mixture on a block wall. Figure 8 of the patent
is shown below.
(See formula 1)
Claim 7 of the Winn patent reads as follows:
In the manufacture of fibre-reinforced structures, in which
multi-strand continuous fiber roving is passed through a flow
channel to a discharge means from a supply spool disposed in
an enclosed container, the method which comprises maintaining
the pressure within said container and within said flow channel
in excess of atmospheric pressure, embracing said continuous
fiber roving in air flowing from said pressurized container to
said discharge means through said flow channel and controlling
the movement of said fiber roving through said flow channel by
the opening or closure of said discharge means.
Curzio discloses the use of reinforcing arches on which rapid setting cement
mortar is sprayed. Figure 1 (below) illustrates that invention.
(See formula 1)
In the Final Action the examiner stated in part:
Applicant has amended his claims to stress the load-bearing and
self-supporting feature of his method and argues that these
characteristics distinguish over the prior art. This argument
is not accepted.
...
The reference construction is in every respect analogous to that
disclosed by applicant. The roof and walls of applicant's mine
roadway are not solid, i.e. without fracture planes of separation,
for if they were no support would be required. On the contrary,
the walls and roof are composed of discrete blocks and applicant's
spray strengthens the wall and roof in the same manner as that
taught by the British reference, it "permits transference of loads
and stresses throughout the entire structure."
Applicant argues that he has invented a new use for an old material,
the fibre-reinforced cementitious mixture, but no new use is
disclosed. In his disclosure as filed applicant states (page 3, paragraph
4):
"The invention is not limited to supporting mine roadways and it
will be appreciated that pack walls, explosion proof stoppings,
shaft linings and cappings may be sprayed in this way since each
forms at least part of the walls of an underground tunnel". This
is exactly the same use for the old material as taught by the refer-
ence. It emphasizes the sameness of the reference method and
applicant's method. It is held that the above quoted paragraph is
necessary for a perfect understanding of the disclosed method and
it may not be deleted.
The United States patent to Curzio is cited to show there is no
novelty in the use of arches and other reinforcing under the spray
coating as also claimed by applicant.
In response to the Final Action the applicant stated (in part):
The only relevant embodiment of British Specification No. 1,042,606
is illustrated in Figure 8 and its accompanying description
appearing at pages 5 and 6 of the reference. In particular, the
method associated with Figure 8 clearly recites that the
structural elements are dry stacked by any suitable means in-
cluding hand labour. In this regard, page 5 lines 40 and follow-
ing clearly provides that the dry stacked structural elements must
be self-supporting or otherwise maintained erect temporarily.
As is also clearly apparent from lines 51 and following of
page 5 of this disclosure, the reasons for applying the spray
of cementitious mixture to the stack of structural elements
is to provide greater structural strength than would be pro-
duced by conventional methods of mortaring or brick laying.
Further, at lines 105 and following of page 5, it is noted
that the stacked block wall produced by the method according
to the British Specification incorporates load supporting
capabilities not previously achieved in mortar construction
since the monolithic membrane joins the elements of the wall
and strengthens the wall throughout the entire inner and
outer surfaces. As a result, the resulting wall will support
and withstand greater beam loads than conventional masonry
construction because of the capability of the wall to act as
a monolithic structure even though it is formed from basically
separate elements such as the bricks illustrated in Figure 8.
As a further advantage, it is also noted at lines 125 and
following, of page 5, that the wall may be formed to utilize
broken blocks or bricks and second grade elements ordinarily
unacceptable in usual construction. Further, it is also noted
in the disclosure that the erection and ultimate construction
costs are substantially less than conventional brick or block
walls in which mortar is placed between the blocks by trowel or
by hand or by other conventional methods. (See page 6, lines
18 ff.).
(3) It is Applicant's submission that a disclosure which teaches
a method of spraying a cementitious mixture on opposing surfaces
of a block wall comprising a plurality of stacked dry structural
elements neither anticipates nor renders obvious a method com-
prising the spraying of a similar mixture on the walls and/or
roof of an excavated underground tunnel so as to form a load-
bearing, self-supporting tunnel lining. Since the tunnel lining
produced according to Applicant's method is self-supporting,
the same does not require that any reinforcements be erected.
...
It is Applicant's submission that it would not be obvious to a
person skilled in the art of constructing underground tunnels,
such as a mining engineer, to look to a specification which deals
with the spraying of dry block walls as a solution to providing a
more efficient method of providing a load-bearing, self-supporting
lining for the roof and/or walls of an underground tunnel. The
Examiner's position that the reference teaches a method which
is in every respect analogous to that disclosed by the Applicant
is quite incorrect. The Examiner submits that the walls and roof
of Applicant's underground tunnel are composed of discrete blocks
and that Applicant's spray strengthens the walls and roof in the
same manner as that taught by the Winn patent. In this regard,
the Examiner's completely ignoring the fact that the British
Specification explicitly requires the providing of a stack of dry
blocks which are either self-supporting or otherwise maintained
erect temporarily.
The question to be considered by the Board is whether or not the appli-
cant has made a patentable advance in the art. Claim 1 of this application
reads as follows:
A method of supporting an excavated earth roof and/or
excavated earth walls of an underground tunnel by spraying
directly onto said excavated earth roof and/or excavated
earth walls a fibre-reinforced cementitious mixture and
allowing concrete thereby formed to harden into a load-
bearing, self-supporting tunnel lining.
At the Hearing Mr. Partington emphasized that the invention resides in the
new use of an old material, which is applying a fibre-reinforced cement-
itious mixture to an underground tunnel. He raised some interesting argu-
ments which must be considered carefully. All the claims are directed to
a method of supporting an excavated earth roof and walls of an underground
tunnel.
In the Final Action the examiner discussed in great detail Figure 8 of
the Winn patent, which is concerned with the formation of concrete blocks
reinforced with a sheath of cement strengthened with fibre roving (glass
fibres or the like). He also questioned the applicant's allegation that
his is a new use for an old material.
The Winn patent shows that the use of a "fibre-reinforced cementitious
mixture" on a block wall is known. As evidenced in any mining engineer's
handbook and acknowledged by the applicant at the Hearing, it is also well
known to use "shotcrete" or "gunite" on the rock surface of underground
tunnels. Shotcrete and gunite are cementous formulations which are not
fibre reinforced.
The applicant puts emphasis on the fact that the method shown in Figure 8
of the British patent to Winn relates to structural elements that are dry
stacked by any suitable means, including hand labour. He states that "the
dry stacked structural elements must be self supporting or otherwise
maintained erect temporarily." Depending on the rock formation, a mine
tunnel consists of stacked components which must be self supporting or other-
wise maintained erect temporarily. Since the roof and walls of a tunnel
consist of discrete blocks which have fracture planes of separation the forma-
tion is one of discrete elements, which essentially is no different from that
of Winn.
Another feature stressed by the applicant is that his arrangement does not
require a wire mesh reinforcing on the surface of the tunnel prior to spraying
with the fibre-reinforced cementitious mixture. Yet "shotcrete" or "gunite" are
applied directly to the rock surface of an underground tunnel, and this has
been recognized as an effective and economical means of wall support in the
industry for some time. In any event Winn does not require a wire mesh on the
wall surface before applying his fibre-reinforced mixture.
Another point made by the applicant was that the apparatus in Winn would not
work satisfactorily under moisture and dust conditions encountered in tunnelling.
Since the applicant is only concerned with a method of supporting an excavated
earth roof wall and has not described any apparatus in his specification, we
need not consider that issue.
The applicant has said at the Hearing that his construction offers improved
fire resistance, and is effective as an air and moisture sealant. However
such beneficial results are inherent characteristics of the well-known "gunite"
process, and of course in the Winn process, and hardly lend patentability to
the alleged invention. In any event the disclosure of the application does not make
any reference to these alleged advantages.
In support of his position, the applicant has submitted affidavits from
Mr. E. Murphy (now retired from the U.S. Bureau of Mines) and Mr. P.B. Reeves
(Director General of the National Coal Board and Director of Planning Major
Projects in Great Britain). Both affiants state that they were aware of the use
of fibre-reinforced concrete before applicant's "Caledonian" process was
introduced in 1971. The advantages prescribed in the affidavits to the new
process, such as load bearing, self-supporting irregular wall surface, transfer of
load stresses, and greater tensile and support strength, were all covered
by Winn. For example, page 5 of his disclosure, at lines 105 ff., reads as follows:
Production of stacked block wall through the method above described
incorporates load supporting capabilities not heretofore achieved
in mortar construction. This results from the fact that the mono-
lithic membrane or sheath 122 joins the elements of the wall and
strengthens the wall throughout the entire inner and outer surfaces.
This permits transference of loads and stresses throughout the
entire structure. As an example, the stacked block wall has greater
than normal resistance to shearing and damage caused to foundations
by beam loads as ordinarily encountered on isolated sections of the
wall. The monolithic system, in other words, will support and
withstand greater beam loads than conventional masonry construction
because of the capability of this wall to act as a monolithic
structure even though it is formed from basically separate elements
such as the bricks illustrated in Figure 8. The wall may be
formed to utilize broken blocks or bricks and second grade elements
ordinarily unacceptable in usual construction. The practical result
is to permit far more economical construction with substantially
greater tensile and support strength characteristics.
We cannot consequently see how the advantages ascribed in the affidavits to
the alleged invention differ from what one would expect to flow from its application
in mines.
It is clear that the overall objective of Winn is the same as that of the
applicant. The properties and advantages of using the reinforced concrete is
well documented in the Winn reference. One difference is that Winn did not
mention that his process could be used in a mining tunnel.
It is well established that a new use of a known material employing properties
or advantages not apparent in the old material may be inventive, providing it
is not obvious to recognize these advantages and properties. The Court in
Van Heusen Inc. v. Tooke Bros. Ltd. Ex. C.R. (1929) 89 at 97, stated however,
that:
There is no invention in a mere adaptation of an idea in a well
known manner for a well known or clear purpose in a well known
art, without ingenuity....
And at page 99:
A patent for the mere new use of a known contrivance, without
any additional ingenuity in overcoming fresh difficulties, is
bad, and cannot be supported. If the new use involves no ingenuity,
but is in manner and purpose analogous to the old use, although
not quite the same, there is no invention. (emphasis added)
We believe that the applicant's use of fibre-reinforced concrete in which
there is served no function or purpose different from the old use does not
warrant patent protection.
Pertinent to our finding is the rationale of the court in Bergeon v. De Kermor
Electric Heating Co., Ltd. (1927) Ex. C.R. at 188, where Audette J, stated:
The adaptation of old continuances or denier of a similar nature
to a new or similar purpose, especially to the same class of
articles, performing an old well known function will not amount to or
constitute invention.
...
In the present case the improvement claimed consists in a combin-
ation which, considering the state of the prior art, discloses
no new function or discovery which could, to my mind, amount to
invention. There is no sufficient invention in merely applying
well known things, in a manner or to a purpose which is analogous
to the manner as to the purpose in or to which it has been previously
applied.
Claim 1 is directed to a method of supporting an excavated underground tunnel
by spraying with a fibre-reinforced cementitious mixture. The material used is
old, and the use of similar materials for that purpose is old. We note, too,
that in the application as originally filed, page 3 stated: "The invention
is not limited to supporting mine roadways and it will be appreciated that pack
walls, explosive-proof stoppings, shaft linings and cappings may be sprayed in
this way since each forms at least part of the walls of an underground
tunnel. This paragraph would seem clearly to link the sprayed structure of
the reference to the sprayed structure of the applicant. In our view claim 1
does not define a patentable advance in the art beyond the teaching of Winn,
and such common general knowledge as is taught by Curzio. It covers a mere
substitution of a known material to an analogous purpose, and the result is expected.
The method serves no function or purpose patentably different from the old
use. The applicant is applying a well known thing in a manner or to a
purpose which is analogous to the manner or to the purpose in or to which it
has been previously applied (see Bergeon v. De Kermor, supra). Claim 1 should
be refused.
Claims 2 to 9, which depend directly or indirectly on claim 1, relate to
the type, the size, and the percentage by weight of the fibre-reinforcement
used. These features contribute nothing patentable to the subject matter of
refused claim 1.
Claim 10 is directed to filling cavities before spraying. It recites essen-
tially the same method as that taught on page 5 of the Winn patent.
Claims 11 and 12 add support means to the tunnel. There is nothing of
significance in doing so.
We are satisfied that neither the claims nor the specification as a whole
are directed to a patentable advance in the art over the cited references.
We recommend that the decision in the Final Action to refuse the application
be affirmed.
J.F. Hughes
Assistant Chairman
Patent Appeal Board
I have reviewed the prosecution of this application and the recommendations
of the Patent Appeal Board. It is my decision that this application should
be refused. If the applicant intends to appeal this decision, he must do
so within six months of the date of this Decision (see Sec. 44).
J.H.A. Gari‚py
Commissioner of Patents
Dated at Hull, Quebec
this 20th. day of December, 1976
Agent for Applicant
Alan Swabey & Co.
625 President Kennedy Ave.
Montreal, P.Q.