COMMISSIONER'S DECISION
OBVIOUSNESS: Improvements in conveyor belts
The application relates to filament-like reinforcing members embedded in
conveyor belts. It was refused for failing to define a patentable advance
in the art over the references cited.
Final Action: Affirmed.
This decision deals with a request for review by the Commissioner of
Patents of the Examiner's Final Action dated December 4, 1975, on
application 165,164 (Class 198-86). The application was filed on
February 28, 1973, in the name of Harald Simonsen et al, and is entitled
"Improvements In Or Relating To Conveyor Belts;"
The application relates to a conveyor belt (7) made of rubber-like plastic
matexial having filament-like reinforcing members (6) embedded therein.
The reinforcing members are mutually spaced apart and extend parallel to
one another in a longitudinal direction. Figure 2 of this application,
shown below, is illustrative of that arrangement.
<IMG>
In the Final Action the examiner refused the application for failing to
define patentable subject matter over the following references:
Reference Re-Applied
Canadian Patent
468,332 Sept. 26, 1950 Freedlander et al
Reference Applied
Mining Engineer's Handbook, Vol. 1, Third Edition, Robert Peele,
Pages 12-20, 12-21, Figures 31(d) and 32(a). Published by
John Wiley and Sons, Inc. in September 1963.
Freedlander shows a mechanical belt made of an elastomeric material having
filamentary reinforcing members 16 embedded therein. The reinforcing
members being arranged substantially parallel and in spaced relationship
to each other. Each member consisting of a plurality of steel wires 10
twisted together to form a single strand. Figures 1, 2 and 3 shown below,
illustrates that invention:
<IMGS>
The Mining Handbook (Peele's) shows that it is old and well-known to form
a strand from wires wrapped around a core member having a cross-sectional
area larger than the wires forming the remainder of the strand.
In the Final Action the examiner stated (in part):
In applicant's letter of May 5, 1975 it is argued that Freed-
lander et al mentions the use of cables in their disclosure,
whereas the applicant specifies strands made of twisted wire.
It is acknowledged that the Freedlander et al Patent uses the
expression "cables" to describe the reinforcing elements, but
a close examination of the disclosure in conjunction with
Figure 1 reveals that Freedlander et al's'table" is in fact a
strand in precisely the same sense as applicant's usage of
the term "strand", that is, an element formed by twisting a
plurality of individual monofilamentary wire.
Clearly the expression "strand" is significant only when
describing the structure of a rope or cable comprising a
plurality of strands. In the case of applicant's and
Freedlander et al's belts the reinforcing elements are
the same structurally, and are not intended to be used
in the manufacture of ropes or cables. Consequently, it
really does not matter whether one chooses to call the
reinforcing element a strand or a cable, provided the terms
as used in the respective disclosures describe the same
structures.
Figure 1 of the Freedlander et al patent shows each "strand"
formed from monofilamentary wires in a single twisting
operation, as defined in claim 2.
Figure 2 of the Freedlander et al patent shows each "strand"
formed from wires in a multiple step twisting operation, as
defined in claim 3.
The wires used in Freedlander et al's reinforcing element
are circular in cross section and have substantially iden-
tical cross sectional areas, as defined in claims 4 and 5.
The "strands" in Freedlander et al's device have a cir-
cular cross-section as defined in claim 7.
Figure 3(d) on page 12-20 of Peele's Mining Engineering
Handbook, shows that it is old and well-known to form a
strand from wires wrapped around a core member having a
cross-sectional area larger than the wires forming the
remainder of the strand, as defined in claim 7.
Figure 32(a) on page 12-21 of Peele's Mining Engineering
Handbook, shows a strand having a cross-sectional area
which deviates from the circular form, as defined in
claim 8.
In response to the Final Action the applicant argues against the rejection
of the application and maintains that the Freedlander patent relates to
a power transmission belt as opposed to a conveyor belt. He further
argues that the strength members in Freedlander are designated as cables
which are built up of multiplicity of fine wires. He also stated (in
part):
...
A conveyor belt according to the present invention is
characterised primarily in that the strength members
are formed of strands of wires united in a single twist-
ing operation. Preferably, the wires are monofile round
steel wires, and the strands are selectively composed of
wires of uniform cross section, or the strands are made
of cross sectionally uniform wires which are wound around
a core wire which has a greater cross sectional area than
the indivdual wires wound around said core wire.
When making a conveyor belt according to the present in-
vention, the manufacturer starts with strands formed of
wires rather than with a finished steel cable. The
strands are embedded in the elastomeric material of the
belt body in much the same manner as steel cables would
be secured therein. Thus the strand-reinforced belts
are a compromise between fabric and steel cable belts.
The strands are less costly to use than a complete steel
cable. On the other hand, the strands employed in con-
veyor belts have the same advantages over high strength
fabric belts as do steel cable conveyor belts. For
smaller conveyor installations with relatively low pull-
ing forces and secondary impact stresses, the invention
makes possible the employment of steel reinforced belts
while avoiding the uneconomical over-dimensions of steel
cables. The relatively thin strands can be inserted in
greater numbers than is the case when finished cables
are used so that a greater total surface of the steel
cables can be reinforced to ensure improved durability
over steel cable belts.
...
Applicant provides a reinforced conveyor belt which is a
definite improvement over fabric-reinforced belts and
has, in addition, features and advantages steel cable
belts do not have. For example, the present belt is
less costly to manufacture, can be made lighter and more
durable than conventional cable-reinforced belts. This
allows a belt provided with steel strength member where
hitherto it was not practical to do so and fabric had
to be relied upon for the required strength and other
characteristics required by conveyor belts. A simple
solution is offered to an outstanding unsolved problem
and applicant has met other requirements of invention
in addition to economy and overall effectiveness of the
conveyor belt. On so doing, applicant believes he is
entitled to the patent protection defined by the present
claims and therefore allowance of this application is
now respectfully requested.
The question before us is whether the application is directed towards a
patentable advance in the art. The examiner rejected the claims and the
application as a whole. Claim 1 reads as follows:
A conveyor belt made of rubber or a rubber-like plastics
material and haying filamentary reinforcing members
embedded therein, said members being arranged substant-
ially parallel and in spaced relationship to each other
and extending in the longitudinal direction of said belt
while being embedded in bonding connection with the
material of the belt, said reinforcing members each con-
sisting of a plurality of steel wires twisted together
to form a single strand.
The applicant points out that Freedlander is concerned with a power trans-
mission belt whereas the present application refers to a conveyor belt.
We observe however, that Freedlander states that his invention "relates.
to reinforced belts, and particularly to V-belts having a neutral axis
section comprising fine metal wires". (emphases added )
The applicant advanced the argument that the strength members in Freed-
lander are designed as cables which are built up of strands, the strands
consisting of a multiplicity of fine wires. We are not persuaded however,
that the evidence lays the formal foundation for that argument. Freed-
lander (Figure 1 supra,) shows each "strand" formed from monofilamentary wires
in a single twisting operation, while his Figure 2, supra, shows each
"strand" formed in a multiple step twisting operation. In our view Freed-
lander's "cable" is also a strand in precisely the same sense as the app-
licant's usage of the term "strand," that is, an element formed by twisting
a plurality of individual monofilamentary wires. In any event the applicant
in response to the Final Action states on page 4, lines 7 f.f., as follows
"The belt of the Canadian patent [Freedlander] is a V-shaped driving belt
with wire strands closely packed in the neutral zone of the belt." (emphasis
added) Freedlander also states that his invention relates to "wire rein-
forced belts, and particularly to V-belts having a neutral axis section com-
prising fine metal wires." (emphasis added) Strictly speaking wires are
used (in a twisting operation) to make strands, while strands are used (in
a twisting operation) to make cables.
The applicant maintains that the strands of the belt, in the instant app-
lication, are spaced transversely across the belt. This feature, of
course, is a common expedient in the conveyor belt art. He also states
that his invention "relates to so-called steel cable belting as compared
with conventional belting incorporating a number of plies of fabric."
In the same vein Freedlander, while discussing the prior art, states:
"More recently, cables [strands] formed of twisted or braided wire of
approximately 0.005" diameter have been used in place of textile cord."
In our view they are discussing the same concept. Freedlander goes on
to discuss his advance in the art which is an electro treatment for the
purpose of depositing a surface coating to the reinforcing strands so
that "a substantial degree of adhesion will take place between the
plated wire and the rubber composition of which the body of the belt is
made.
We turn now to a consideration of the claims. Claim 1 is directed to a
conveyor belt with reinforcing members therein, the reinforcing member
being bonded to the material of the belt and consisting of a plurality
of steel wires twisted together to form a single strand. This, in our
view, is substantially what is taught, as discussed above, by Freedlander
keeping in mind that he uses the term cable in precisely the sense as the
applicant's usage of the term strand, We agree that the claim is restricted
to a conveyor belt, but Freedlander invention "relates to a wire rein-
forced belts...." The concept and the improved result is the same. Claim 1,
in our view, is not directed to a patentable advance in the art and should
be refused.
Claims 2 and 3, which are dependent on claim 1, are directed to a specific
twisting operation which is clearly shown in Figures 1 and 2 of Freed-
lander.
Claims 4 and 5, which are dependent indirectly on claim 1, relates to features
such as the cross-sectional shape of the wires and fail to add a patentable
feature to refused claim 1.
The added features of claims 6, 7 and 8, such as the use of the core wire
or shape of the strand, are taught by Freedlander and, or Peele's Mining
Handbook (cited by the examiner).
In summary, we are satisfied that the claims, and the application as a
whole, are not directed to a patentable advance in the art over the
references cited by the examiner. There is, in our view, no result which
could have flowed from an inventive step. We recommend that the decision
in the Final Action to refuse the application be affirmed.
J.F. Hughes
Assistant Chairman
Patent Appeal Board, Canada,
I have studied the prosecution of this application and reviewed the
recommendation of the Patent Appeal Board. In the circumstances I
have decided to refuse the grant of a patent on this application. The
applicant has six months within which to appeal this decision under
the provisions of Section 44 of the Patent Act.
J.H.A. Gari‚py
Commissioner of Patents
Dated at Hull, Quebec
this 21st day of February, 1977
Agent for Applicant
Fetherstonhaugh & Co.
Suite 456
409 Granville Street
Vancouver, B.C.
V6C 1H5