Barber-Colman Co. v. A. G. Redmond Co.

7 F. Supp. 508, 1934 U.S. Dist. LEXIS 1937
CourtDistrict Court, E.D. Michigan
DecidedJuly 5, 1934
DocketNo. 440
StatusPublished
Cited by2 cases

This text of 7 F. Supp. 508 (Barber-Colman Co. v. A. G. Redmond Co.) is published on Counsel Stack Legal Research, covering District Court, E.D. Michigan primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Barber-Colman Co. v. A. G. Redmond Co., 7 F. Supp. 508, 1934 U.S. Dist. LEXIS 1937 (E.D. Mich. 1934).

Opinion

TUTTLE, District Judge.

This suit involves United States patent No. 1,822,679, issued to Duncan J. Stewart and Edgar D. Lilja on September 8,1931. It has to do with small-size, alternating current induction motors of the core type. This type of motor consists of a stator, composed of steel laminations, with a portion of the stator encircled by a coil of copper wire-known as the “field coil." In these laminations is a circular opening into which a rotor is placed. The portions of the stator adjacent the rotor opening are known as the [509]*509“stator poles.” The faces of those poles are divided into sections by copper rings, known as “shading rings,” which encircle certain of these sections. The rotor consists of circular steel laminations, along whose circumference is imbedded copper conductors, connected at each end by a copper plate, known as a “squirrel cage rotor.”

The accepted theoretical opinion for the operation of this motor, is that when a current of electricity is passed through the field coil certain magnetic fluxes are set up to pass in a definite direction through the stator. As electricity produces flux or magnetism, so flux will produce electrical currents. As this flux traveling through the stator reaches the shading coils, currents are set uj> in these coils, which react on the flux to distribute it to the rotor in the desired magnitudes and time relationships, producing a turning effort on the rotor, causing it to revolve.

We are dealing more with flux or magnetism which results from electricity, than with electricity itself, and though used in many ways for nearly half a century, there are many points that those most expert cannot definitely explain.

I have had the assistance of able and diligent counsel and of experts from three great universities. I am convinced that trying the ease in January of 1934 it cannot be any better presented and the record with reasonable effort made any more complete than it now is.

In these motors we find many of the same principles that we find in other motors. The great art involving electricity and flux should not be subdivided into smaller arts, so as to set this small type of motor up in an art by itself.

The patent claims a new combination, not that the principles used are new, nor that the individual elements used are new, but that the combination of those elements is new, producing a new result.

Patentees started out with a squirrel cage rotor that was old in the art, but claim a definite proportion of copper to iron to get best results. It’ is not claimed to be a new combination to use a rotor and stator, but plaintiff claims new dimensions in the stator for correct relation to the other parts. Shading rings are old; it is old to place them in a motor, either single or multiple. It is not claimed to be new to have the three combinations, but plaintiff claims that what is new in that element of combinations is a certain resistance shading ring. Plaintiffs claim low resistance shading rings in combination with a stator of particular dimensions, and a rotor made of certain proportions. Then is brought into this combination the fact that the unshaded portion of the flux follows the contour of the rotor to a point beyond the median line.

The unshaded flux is that flux coming from that portion of the stator pole which is not encircled by shading coils. Again it is old in the art to have this portion of the flux closely following the contour of the rotor as shown in patents to Warren, Nos. 1,383;-433,1918; 1,283,435,1918; 1,495,827,1924; 1,497,394,1924; and 1,546,269,1925. There, even though the pole tips were of different construction, they did closely follow the contour of the rotor and extended beyond the median line. This is also shown in patents to Shivers, No. 1,654,840, 1928; Cowles, No. 1,734,941, 1929; and Homi, No. 1,720,217, 1929'. It is the obvious and the natural way to construct a motor to make a round hole in the stator and put the rotor in it, which would result in pole tip extensions closely following the rotor contour and would cause the flux to do likewise.

In the British patent to Landis & Gyr, No. 212i,263, 1924, it seems that the theory of flux is better understood than in the patent in suit. They attempted to pass a portion of unshaded flux toi the opposite pole, without having it going through the rotor, by means of a by-pass' or shunt; but it is also stated that it could be done by a solid extension of the pole tip> closed around the rotor, which would be the natural way. It was, therefore, well known prior to the patent in suit that some flux would pass to the opposite pole without passing through the rotor.

There are conflicting theories as to whether or not it is desirable to pass a portion of this flux to the opposite pole without it passing through the rotor, in order to get a proper time lag or phase. Plaintiff’s patent states that substantially all the flux goes into the rotor. Landis & Gyr in their patent, referred to, teach that it is beneficial to pass some flux direct to the opposite pole. I believe that for decision of this case theories are of little importance. However, from the experiments shown, I believe that the teachings of Landis & Gyr are the best thought on the subject of passing the flux. This is contrary to the theory of the patent in suit. I believe that a substantial portion does pass direct to the opposite pole, and that this is necessary to obtain a successful motor. I think that if the patentees in this patent were correct in theory as to how the flux passes, they would not be able to obtain an efficient motor.

[510]*510Every element contained in plaintiff’s patent is found in the prior art. You may not find a stator in just the exact proportion, or the exact field coil; but the field coil around the stator in the old structures was doing1 the same function it is here. The stator performed the same duties. The rotor was of the same squirrel cage construction, the only difference being plaintiff’s claim that it should be one-sixth copper. Shading.rings, their effect and how they worked, were just as well understood before this patent. It was also known to extend the pole tips closely following the rotor contour, solid or with air gaps at or beyond the median line. The combination is of all old elements.

This is a difficult field of science not yet fully understood, and every one desiring to build a motor must cut and try, using things known, to get the results they want, or copy one already existing, suitable for the purpose. This cut and try method'was followed by the patentees using these old principles.’ They have not established any new and useful rules. If you permit one man to experiment and make this shorter and that longer, using all old elements in the same way, until be gets down to a good working device, and then he is able to get a patent on those dimensions, which exact dimensions you do not find anywhere in the art,, then other men must stop experimenting in that preferred sphere because a patent has been granted. That is a dangerous thing, harmful to the business world, and it is the duty of the court to closely scrutinize a patent of this kind for the purpose of discovering whether there is really a new inventive thought, or simply a desirable type of the old thing. I think this ease is a good illustration of that danger.

It is my opinion from the evidence that there is no new combination produced and no new result accomplished and no inventive genius exercised. That being so, the patent cannot be sustained in view of the following cases: In re Prescott et al.

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Related

Barber-Colman Co. v. Sampsel Time Control, Inc.
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7 F. Supp. 508, 1934 U.S. Dist. LEXIS 1937, Counsel Stack Legal Research, https://law.counselstack.com/opinion/barber-colman-co-v-a-g-redmond-co-mied-1934.