COMMISSIONER'S DECISION
Obviousness: Terminals for electrical wires.
The end of electrical wires are heated to form a molten ball. These are pear-shaped
nodules formed by the combined effect of surface tension and gravity upon the nodule.
The nodules can then be shaped to form easily-attached connectors. Claim 1, which
was directed to the pear-shaped nodule, was refused in view of the cited references,
common general knowledge and the physical phenomena involved inn forming such a
shape. A claim directed to the novel practical application of the invention,
which includes the step of deforming the solidified, pear-shaped nodule, to provide
a shaped free-ended terminal on the end of the conductor, was found allowable.
Final Action: Affirmed.
********************
This decision deals faith a request for review by the Commissioner of Pat-
ents of the Examiner's Final Action dated March 29, 1976, on application
171,595 (Class 26-134). The application was filed on May 11, 1973, in
the name of Gideon A. DuRocher et al, and is entitled "Terminating and
Splicing Electrical Conductors." The Patent Appeal Board conducted a
Hearing on November 16, 1977, at which Mr. D.N. Deeth represented the
applicant.
The application is directed to preparing terminals at the end of electrical
wires. The end of the wire is heated to form a molten mass, which is a pear-
shaped nodule at the end of the wire due to the combined effect of surface
tension and gravity upon the droplet . The terminal can also be shaped to
form connectors, so the wire can be easily attached to terminals. Figures
1 and 10 shown below illustrate the invention:
(See formula 1)
In the Final Action the examiner refused claims 1 to 14 and 18 to 21 for
failing to define patentable subject matter over the following United States
references:
3,684,474 Aug. 15, 1972 Chisholm
3,561,084 Feb. 9, 1971 Sims
3,397,451 Aug. 20, 1968 Avedissian et al
Each of the cited references discloses the method of obtaining a nodule of
metal on the end of a wire by holding a wire with its longitudinal axis
vertical, heating the lower end of the wire until it melts and forms a nodule
having a diameter greater than that of the wire, and removing the source of
heat before the molten nodule drops from the end of the wire. Upon cooling,
there will remain at the end of the wire a solidified bulbous nodule.
We note however, that the Chisholm reference was overcome by the presentation
of a certified copy of the applicant's corresponding United States application,
thereby establishing an effective filing date of May 18, 1972.
In the Final Action the examiner had this to say (in part):
In claim 1 applicant refers to the combined action of the forces
of gravity and surface tension. These forces and their influence
have not been discussed in the references. However, they are
natural forces acting upon the molten portion of the wire. Whether
described or not, the forces are present and will shape the metal
immediately upon melting. The shape of the nodule will,in all
cases, be determined by the surface tension and density of the
molten metal and the shape of the nodule will be that of a teardrop
just prior to necking in and detachment from the wire. The failure
of the references to illustrate this shape accurately cannot be
readily explained. However, it is noted that a draftsman would
use a compass to draw such a shape and may take greater or lesser care
in attempting to depict a teardrop shape. It is apparent in figure
1 of the Sims patent that more care has been taken to make an
accurate representation of the shape than in the other two refer-
ences. Even applicant's drawings are somewhat inaccurate in
their representation of the shape in that they show (in figures
1, 19, 22, 23, 24 and 26) a hemispherical lower portion while, in
fact no portion of a teardrop is truly spherical and there is not
a proper illustration of the reverse-curved upper portion which
is characteristic of teardrop shapes.
Since the references teach the steps of heating the end of a
wire to form a molten nodule having a diameter greater than that
of the wire, and, in the absence of any teaching of any means
to prevent the formation of a natural teardrop shape, the
nodules formed by this method will have a teardrop shape.
In addition to that which is taught in the cited references,
applicant has included in claim 1 a description of that which
naturally occurs in the method. This does not lend any patentable
distinction to the claim. The additional definition of claims
2, 7 and 20 is readily apparent in each of the cited references
which anticipate claims 1, 2, 7 and 20.
The use of an oxygen atmosphere or an inert atmosphere as de-
fined in claims 3, 4 and 21 is commonly known in the art and as
such does not lend any patentable distinction to the claims.
Similarly to perform the method on multi-strand conductors as in
claims 5 and 6 is not an inventive improvenent over the use of the
method of the prior art on single-conductor wires. The use of an
electric arc to melt wire as in claims 8 to 11 is commonly known in
the art. All of the abovementioned features are known to those skilled
in the art and it is to be expected of one skilled in the art to
employ such techniques. Further, as employed by applicant they
do not provide any unexpected beneficial result upon which to pre-
dicate an assertion of patentable ingenuity and novelty. Claims
3 to 6, 8 to 11 and 21 are rejected for failure to define any
patentable improvement beyond common knowledge and expected skill
as applied to each of the cited references.
...
In response to the Final Action the applicant made mirror amendments to claims
1 and 2, and presented tho following arguments:
...
One particular advantage of the invention is that with this
method, the pear-shaped nodule, as illustrated in figure 1, or
figure 31 or figure 32, merges smoothly into the bared or unmelted
part of the conductor. This avoids any sharp or abrupt angles in
the termination, which are liable to failure under stress, as sharp
or abrupt angles tend to concentrate lines of stress in the area
of the sharp angle. This feature is also discussed at page 10 of
the application, lines 14 to 25.
In an interview granted by the Examiner to the applicant's represent-
ative, a point was discussed as to whether the method set out in
the claims would give the desired results with all metals. It
should first be pointed out that the novelty of the invention does
not reside in the nature of the metal used. The invention is a novel
procedure which can give advantageous terminations. The nature of
the metal used is not of the essence of the invention. The applicants
have used various metals, and have not found any metal to be
inappropriate for use with the method of the invention. With the
amendments proposed above, the claim has been clarified by stating
that the metal is normally solid at room temperature.
...
There is no disclosure in Sims or Avedissian that a pear-shaped nodule
may be formed by continuing the heating beyond an initial stage as
required by claim 1. Thus, the ball 19 and body 14 temporarily
formed in Avedissian and Sims have a spherical shape, as shown
on the enclosed sample of white-covered wire. If ,contrary
to the teachings of Avedissian and Sims, the ball ends obtained
temporarily were used as a termination, such spherical termina-
tion would exhibit an abrupt angle between the ball or body and
the unmelted part of the wire. This gives rise to problems and
disadvantages of stress concentration at the abruptly angled parts,
leading to a termination of reduced strength.
In Sims, the body 14 is flattened into bonding contact with the
filament 10 and filament post 12,and is then severed from its
wire 16. In Avedissian, the ball 19 is flattened into bonding
contact with a wafer 12. There is no suggestion in Sims or
Avedissian of deforming the solidified end of the conductor so as
to provide a free-ended terminal, such as the terminals of applicants
Figures 4 to 18, as required by applicants claim 2.
Accordingly, applicant considers that the invention as claimed in
claim 1 and its dependent claims provides an advantageous and
ingenious solution to the problem of providing a termination on
the end of a conductor. This solution is not described or suggested
in any of the applied references.
The question to be considered is whether or not the claims in question are
directed to a patentable advance in the art. Amended claim 1 reads as follows:
A method of terminating an end of at least one metallic, electrical
conductor which is normally solid at room temperature comprising
holding said conductor in a position such that its said end lies
in a substantially vertical plane with its free end lowermost;
heating said conductor from its free end to a temperature at which
the metal at said free end becomes molten,continuing said heating
of said conductor for a period of time such that a nodule is formed
and continuing heating until the combined forces of gravity and
surface tension shape the molten metal nodule into an enlarged, pear-
shaped molten mass suspended from said conductor; discontinuing the
heating of said conductor prior to time that the force of
gravity acting on said molten mass causes the latter to separate
from said conductor; any solidifying said molten mass, thereby form-
ing an enlarged, pear-shaped nodule at the free end of said conductor.
At the Hearing Mr. Deeth argued that claim 1, the only independent claim, is
directed to patentable subject matter.
We observe that it is a known procedure to heat an end of a metal wire to
form a bulbous shaped portion (nodule) on the end of the wire. The cited
patent (Avedissian) uses a flame to heat the lower end of a wire (e. g. gold)
which "forms a ball" or nodule on the end of the wire. Figure 5 of that
patent is shown below.
(See formula 1)
Sims (U.S. patent 3,561,084) also heats a gold wire to form a nodule. In
both of these references heat is applied to form a nodule on the end of a
wire.The size and shape of the nodule is dependent upon the amount of heat
and other factors which we,will now discuss.
In considering surface tension it is known that the shape of any collection
of molecules in the liquid state is a sphere if the collection is located in
a gravity-free space. In other words a liquid will, because of the existence
of surface tension, assume the shape for which its area is minimum, namely,
a sphere. On the other hand if we consider liquids in a gravitational field,
such as the earth, the weight of a liquid acts in addition to the surface
tension force. On this point we quote from "Elementary Classical Physics"
by R.T. Weidner, at page 445:
For a sphere of radius r, the effects of surface tension are
proportional to the surface area 4nr2, but: the weight, pro-
portional to the mass of liquid, is proportional to its volume,
~nr3. Thus, the weight varies as r2, whereas the forces of
surface tension vary as r2. As the radius or size of the drop
of liquid increases, the weight becomes increasingly more
significant than surface tension....
It is clear from this that any nodule, as it increases in size, will be de-
formed from its original and essentially spherical shape by gravitational
force. We do not have pictorial views of a copper wire being heated as in
the present application, but we do have a series of high-speed photographs of
successive stages in the formation of a drop of milk at the end of a vertical
tube ("College Physics" by F.W. Scars - Addison - Wesley Publishing Company,
Inc. Reading Massachusetts U.S.A., page 258);
<IMG>
We realize that in the above photos we are dealing with two different sub-
stances. It is knohn, however, that the magnitude of the surface stress
depends upon tho nature of the liquid and the material composing the wall.
We do observe from the photos what takes place when gravity becomes more
significant than surface. tension. The applicant should not be permitted to
claim, per se, any of these naturally known occurring shapes.
At the Hearing Mr. Deeth stressed the importance of a "pear-shaped" end
which has a fillet of at the junction of the wire and the enlarged end. This
is advantageous both to the applicant and to Avedissian. They both disclose
nodules having diameters greater than the diameter of the wire. The shape of
nodules actually produced will depend on the size and weight of the nodules.
In all three disclosures (the application and the cited art) the wires are held
vertically and the lower end is heated until a nodule is formed. Since the
basic steps are the same, the product must be essentially the same. Any
variations will depend upon the kind of metal, its density, surface tension,
wetability and rate and duration of the application of treat to the wire. Once
heat is applied and a molten nodule starts to form, its development follows
the well known sequence in the formulation of teardrops. By stopping the
application of heat at any particular moment one can attain a nodule having
any of the shapes through which a developing teardrop progresses.
The applicant stressed the need of a fillet to reduce stress, but both
references disclose such fillets and in the development of teardrops such
fillets will naturally occur. In any event the applicant does not show
such fillets in his drawings.
We turn now to a consideration of the claims. Claims 15, 16 and 17 were not
refused in the Final Action.
Claim 1 is essentially directed to orienting a metal wire vertically, heating
the lower end of the wire, and stopping the heating step wren a nodule of the
desired shape is attained. We believe that such steps are not directed to
patentable subject matter when one considers the references, common general
knowledge, and the physical phenomina discussed previously. The applicant did
not discover the claimed shape; he merely observed that he could get that
shape, one which suited his purpose. The prior workers in this field would
at some point however, achieve the same result. We believe that this claim
should be refused.
Claim 2, which depends on 1, was amended in response to the Final Action. It
is now directed to the novel practical application of the invention, which
includes the step of deforming the solidified, pear-shaped nodule, to provide
a shaped free-ended terminal on the end of the conductor. This claim should be
re-written and presented as new claim 1.
Claims 3 to 14 and 18 to 21, which depend directly or indirectly on claim 1,
are directed to variations such as the application and type of heating, make up of
the wire and the use of different metals. These claims do not add any patentable
features to refused claim 1 and should not be allowed. These claims, however,
would be found allowable if made dependent on new claim 1.
In summary, we recommend that the decision in the Final Action to refuse
claims 1 to 14 and 18 to 21 be affirmed, but that amended claim 2 be accepted
when presented in appropriate form as new claim 1.
J.F. Hughes
Assistant Chairman
Patent Appeal Board, Canada
I have reviewed the prosecution of this application and concur with the
recommendation of the Patent Appeal Board. Accordingly, I refuse to grant
a patent on claims 1 to 14 and 18 to 21, but I will accept amended claim 2
when presented in an appropriate amendment as new claim 1. The applicant
has sit months to submit an appropriate amendment, or to appeal my
decision under the provision of Section 44 of the Patent Act.
J.H.A. Gariepy
Commissioner of Patents
Agent for Applicant
Ridout & Maybee
111 Richmond St. W.
Toronto, Ontario
Dated at Hull, Quebec
this 20th. day of December, 1977