COMMISSIONER'S DECISION
SECTION 2 - ACYCLIC DIRECT CURRENT MOTOR
A proposed electric motor was held to be an inoperable theory. No working model
was supplied.
Final Action: Affirmed
**********************
Patent application 312,909 (Cl.310-88), was filed on October 6, 1978
for an invention entitled "D.C. Machine". The inventor is
William R. Cruikshank. The Examiner in charge of the application
took a Final Action on September 21, 1979 refusing to allow it
to proceed to patent.
The application is directed to an acyclic direct current motor or
generator, as distinct from a commutating motor or generator. Claim
1 reads as follows:
A true DC machine consisting of stator frame, stator winding,
main rotor, rotor field poles and rotor shaft; in which
the field poles on the main rotor are of the same magnetic
magnitude and polarity and are directed perpendicular to
the inside periphery of the stator; with the stator winding
conductors perpendicular to the rotor field in axial planes,
the stator core fastened between two stator side frames
with one or more narrow inserts of non-magnetic material
placed between the stator core and each side frame: the
rotor is fastened to but separated from the rotor shaft by
means of a flange at each end rigidly fastened to the
shaft with one or more inserts of non-magnetic material
placed between each flange and the rotor ends, the rotor
having a hole, through the center of somewhat larger diameter
than the shaft: with a means of applying and removing DC
voltages and currents from the machine winding, with a
means of cooling and lubricating machine parts and fasten-
ing machine to rigid supports.
In the Final Action the Examiner refused the application because:
a) The disclosure is insufficient and does not satisfy
Section 36(1) of the Patent Act.
b) The alleged invention is inoperable and does not
satisfy Section 2 of the Patent Act because it is
not useful.
In regard to the insufficiency of the disclosure the Examiner
argued (in part):
In his last letter, applicant has explained a few things,
at least he has explained that by "true D.C. machine" he
wanted to say "homopolar or acyclic" machine. The
examiner was not able to guess that because the machine
described and illustrated in Figs. 1 to 4 is not at all
acyclic. However, it is still held that the present
disclosure is just as insufficient, incomplete and con-
fusing as before, even if all the amendments suggested
in the last letter had been entered.
It is still not clear, how the proposed machine could
produce D.C. , without a comutator, if both windings, on the
stator as well as on the rotor, are wound (See present dis-
closure, page 3, lines 15 to 20).
It is still not clear, how a "squirrel cage rotor", a typ-
ical A.C. machine component, can be of any use in a D.C.
machine. Applicant refers the examiner for an explanation
to pages 5A, lines 24 and 25. These two lines, however,
give no explanation whatsoever. It is still not clear,
how a squirrel-cage winding could be built into the present
machine. Will it be in the rotor or stator? And how could
it produce voltage and current if it is stationary (See
disclosure page 1, lines 21 to 23) and does not move with
respect to the magnetic field. It appears that applicant
knows squirrel cage windings by name only and does not
understand their purpose and function.
The present disclosure is incomplete and indefinite because
it does not say how the slip-rings or current collectors
are arranged on the machine. In particular, it is not
clear how current could be collected from or supplied to
a squirrel cage rotor. This question is even more impor-
tant for a homopolar machine because in such a machine
current collection is a bottleneck and a headache (See
copy from Engineering Handbook supplied by applicant).
Because of all these questions, a person skilled in the
art could not construct a useful machine by following only
applicant's present insufficient disclosure.
In his last letter applicant has proposed to modify
throughout the disclosure the expression "shielded winding"
to read "partially shielded winding". It remains unclear,
however, why windings must be shielded, what is gained,
and what material is used for shielding. (See disclosure
page 1, line 22, etc).
It is still not clear, what the non-magnetic inserts are
supposed to do. Applicant, in his letter, paragraph 5 (b)
says, the non-magnetic insert 3f is "for the purpose of
confining the flux to a particular assembly (as much as
possible)". But it does not. According to lines 2 to 5
of the disclosure, page 4, the normal flux path in Fig. 2
is from inner core 4A to flux rings 3E. The interposed
insert 3f only interrupts this flux path and renders the
machine inefficient, if not useless.
It is held that the present disclosure does not "correctly
and fully describe the invention and its operation or use
as contemplated by the inventor .... in such full, clear,
concise and exact terms as to enable any persor skilled
in the art .... to make, construct, compound or use it,"
as required by Section 36(1) of the Patent Act.
On the question of inoperability of the invention the Examiner
stated (in part):
At the first page of his last letter, in paragraph 3,
the applicant says: "This machine could be more properly
called acyclic or homopolar...". Now this statement
is a radically new revelation because the machine dis-
closed and illustrated does not at all resemble an acyclic
machine, nor can it be operated in an acyclic fashion.
...
There is another reason, why applicant's machine cannot
operate acyclically. In a uniform homopolar magnetic
field the rotor rust be a single straight conductor. It
cannot be wound i.e. looped back and forth. If it were,
the voltages induced in one half of the winding sides
would oppose those induced in the other half, resulting
in a zero output. For this reason, a homopolar machine
with a wound rote will not work. However, that is exactly
what applicant has, a machine with a wound stator (See page
3 of the disclosure, lines 10 and 11) and a wound rotor
(page 3, lines 19 and 20)....
If, then, applicant's machine is not homopolar, it is still
the same machine that was analysed by the examiner on page 4
of the last Action. The three unusual features A, B and
C have been condensed from the present disclosure and
drawings, and it is therefore again held that the alleged
invention is inoperable for the following reasons:
A. Applicant's machine, having a wound rotor, cannot run
on D.C. or. produce D.C. because it has no commutator,
either to energize only certain windings which happen
to be in the gap of the motor, or to rectify the
output of a generator, as the case may be.
B. If all the stator poles facing the rotor have the same
polarity and all rotor poles facing the stator have
the same opposed polarity then each North pole would just
lock with one South pole, and no torque would be pro-
duced by a motor. No voltage would be produced in a
generator because no flux would be cut.
C. If rotor windings were somehow shielded, be it fully
or partially, from the stator flux so as to eliminate
or reduce Back EmF, then no or little flux would cut
the conductors, thus producing no or little voltage in
a generator and no or little torque in a motor.
If it therefore held again that the device described by
applicant is inoperable and not useful.
In response to the Final Action the Applicant says (in part):
a) The objections raised under Sufficiency of Disclosure
are not valid because the machine parts complained about
are Knell known to one knowledgeable in the art for
example slip rings.
b) Objections raised under Operability are not valid be-
cause the machine described do not function and are
not arranged the way the examiner thinks they are and
because he has not correctly applied machine principles.
We have reviewed the disclosure and have taken into consideration the
Applicant's arguments as presented in his letter of December 18, 1979
in reply to the Final Action. On page 2 of the letter the applicant
states (emphasis added):
An acyclic machine by definition is one in which the
field poles do not alternate in polarity so the machines
I have described are definitely acyclic. The machines
shown in the Standard Handbook for Elec. Eng. are essentially
acyclic and UNIPOLAR (they have only one pole which consists
of coils wrapped concentrically about the shaft but on the
stator) . The machines I have described are acyclic but NOT
unipolar.
The following definition of a homopolar generator or a homopolar
machine appears in the "McGraw-Hill Dictionary of Scientific and
Technical Terms" 2nd ed., 1978, D.N. Lapedes, editor in chief:
A direct-current generator in which the poles presented
to the armature are all of the same polarity, so that the
voltage generated in active conductors has the same
polarity at all times; a pure direct current is thus
produced, without commutation, also known as acyclic
machine; homopolar machine; unipolar machine.
An acyclic machine is, therefore, by definition, the same as a
unipolar machine.
The question which the Board must decide is whether the Applicant
has made a new invention which makes the above definition of acyclic
machines outdated, as suggested by the Applicant, or whether there
is some error in the proposed machines which makes them inoperable.
In order to answer this question we repeat here the following
paragraph from the Final Action:
There is another reason, why applicant's machine cannot
operate acyclically. In a uniform homopolar magnetic
field the rotor must be a single straight conductor. It
cannot be wound i.e. looped back and forth. If it were,
the voltage induced in one half of the winding sides
would oppose those induced in the other half, resulting
in a zero output. For this reason, a homopolar machine
with a wound rotor will not work. However, that is
exactly what applicant has, a machine with a wound stator
(See page 3 of the disclosure, lines 10 and 11) and a
wound rotor (page 3 lines 19 and 20).
In reply to this paragraph the Applicant argued on page 3 of his
letter as follows:
Single Straight Conductor.
Since the field poles are on only one side of the
winding or armatures what would induce a voltage in the
opposite side in the opposite direction? The flux changes
direction from perpendicular to parallel.
We place on record as of interest the following prior publication
entitled "Homopolar Induction Machines", Canadian Electrical News by
A.M. Gray, March 1, 1913. The article discusses impossible homopolar
machines, and explains the Examiner's objection and the Applicant's
question as follows:
Much time has been spent in the endeavour to design a
homopolar machine which will not require sliding contact,
and the usual result of such wasted energy is a machine
such as that shown diagrammatically in Fig. 2; tho opera-
tion of this machine is based on one if not on two
fallacies.
<IMG>
If a direct current be passed round the exciting coi1
B, a magnetic field is produced as shown and the assump-
tion is made, which may or may not be correct but which
has not been proven experimentally, that as the rotor C
revolves, the magnetic field revolves with it, and the
lines of force cut the stationary conductor ab generat-
ing a voltage therein; it is also assumed that, since
the conductor bc is brought out through a large opening
and is therefore in a weak magnetic field, the lines of
force will slide around the conductor in some way or
other without cutting it, or, if they do cut the
conductor, that the voltage induced therein will be
very small because of the low flux density in the
surrounding space.
The article goes on to state that the latter assumption is wrong.
Although the flux density in the air space is low, the velocity
of the lines of force is large, and the same number of lines are
cut by a conductor in the air space as by a conductor embedded in
iron. The Applicant has stated in his letter that the expression
for the induced voltage is E=BLV.
In Figure 2 (of the publication), the same total flux
is cut by conductor be as by conductor ab, and the
voltages induced in these conductors are equal and
opposite, so that the resultant voltage measured at
the terminals ac is zero.
Looking at Figure 2, we note that the flux also changes direction
from perpendicular direction to the parallel direction as argued
by the Applicant. Using the well known right-hand rule it is seen
that the voltage induced in line ab cancels the voltage induced
in line bc. We, therefore, must conclude that the dictionary
definition of an acyclic machine should be maintained unchanged
and that in fact Applicant's machines cannot work. It is also
noted that the Applicant apparently does not have a working model
of his machines, though one was requested by the Examiner (para-
graph 8 action of July 23, 1979). This is a further indication
that the applicant's invention is a question of theory which has not
been reduced to a practical form (Sections 28(3) and 40).
To further support our conclusion we refer to page 1 of Applicant's
disclosure which states (in part):
The stator winding may be wound, squirrel cage or shielded
winding with a DC voltage applied to or removed from the
stator windings.
Similarly, claim 1 (12-14) contains the expression:
... with a means of applying and removing DC voltages
and currents from the machine winding ....
Figure 1 of Applicant's drawings shows a stationary stator. Since
the stator does not move,brushes or collectors are not needed on it.
We now quote from the following reference which is cited as of
interest and which is entitled "the Unipolar Generator",
Westinghouse Engineer, March 1956, vol. 16, pages 56-61:
Most unusual is the young do machine designer who
has not schemed to turn the unipolar "inside out"
so the voltage-generating, current-carrying parts
could be on the stator. This would avoid all the
brush and collector problems. However, to date,
all attempts have failed. As Mr. B.G. Lamme once
said, "You can't fool the flux."
We do not think it necessary to discuss this matter any further.
Solutions to the problem which the applicant has set out to solve
have been tried before by many people. All designs of acyclic
machines having voltage generating or current carrying parts on
the stator are unsuccessful because they are based on fallacies as
discussed above.
We have considered all the arguments presented and have carefully
reviewed the application. The Applicant's design of acyclic machines
is based on fallacious theory. We, therefore, support the Examiner's
rejection of the application under Section 2 of the Patent Act for
inoperability.
C.A. Asher S. Kot
Chairman Member
Patient Appeal Board, Canada
I have reviewed the prosecution of this application and considered
the recommendation of the Patent Appeal Board. I concur with
the reasoning and finding of the Board. Accordingly, I refuse to
grant a patent on this application.
J.H.A. Gariepy
Commissioner of Patents
Agent for Applicant
William R. Cruikshank
5300 Tobin St., Apt. 9
Halifax, N.S.
B3H 1S2
Dated at Hull, Quebec
this 20th. day of March, 1980