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Thomas F. Sheridan and C. V. Edwards, for appellant.
W. K. Richardson, for appellee.

Before LURTON, SEVERENS, and RICHARDS, Circuit Judges.

SEVERENS, Circuit Judge. This is an appeal from an interlocutory decree of the Circuit Court sustaining certain claims of a patent, awarding a perpetual injunction, and ordering a reference to a master for the ascertainment of profits and damages. The patent which is the basis of the controversy is No. 508,637, issued to H. G. Reist, as assignor to the complainant, November 14, 1893, for an "improvement in the construction of armature cores" in dynamo electric machines. The bill charged the defendant, the Bullock Electric Manufacturing Company, with infringement. The answer denied that Reist was the first inventor of the devices for which the patent was granted, averred the anticipation thereof by numerous former domestic and foreign patents and earlier publications disclosing the supposed invention of Reist, and also denied infringement. In his specification the patentee states that his object was to improve the construction of armature cores, so as to obtain ample ventilation for dissipating the heat generated therein without detriment to the inductive qualities of the core.

It was well known that in the operation of such machines, heat was generated in the core of the armature by eddies of the magnetic flux in parts remote from the conductor whereby a waste of power was incurred; and besides, the obstruction thus encountered incited heat which might become injurious to the armature. Other factors are suggested which combined to create heat in the core, but that mentioned has been recognized as the principal one. Naturally this difficulty was most serious in large armatures consisting of massive collections of iron. The core of the patent in suit is, says the patentee, to be built up in the usual manner of annular iron laminæ in layers, and is supported by a spider having arms radiating from the shaft, but instead of making the core solid from end to end, he builds it up in sections or bundles of laminæ, and between each two sections he introduces skeleton separators which consist of "ribbed castings, riveted or otherwise suitably fastened to the side of one of the laminæ, and each adapted to bear against the outside lamina of the next section." In another place, he states that, instead of the ribbed castings, he proposes in some cases to make the separators of sheet metal, having one portion turned up at right angles to the other, which latter is "riveted or otherwise secured to" the outside lamina of a section, while the edge of the turned up portion bears against the outside lamina of the next section as in the first instance. These separators, in one form, consist of thin, flat plates secured to the lamina by rivets, and are provided with thin ribs extending outwardly to the outside lamina of the adjacent section, the ribs being radial to the centre of the armature. In another form the ribs are riveted directly on the lamina, and of themselves constitute the separators. In another form several equidistant ribs are assembled on a skeleton form of separator, which are specially adapted to the toothed, or Pacinotti, style of armature; the ribs in such

case bearing against the opposite teeth of the separated sections. The material of which the separators shall be composed is "brass or other metal, cast in the shape desired." For a more complete understanding of the structure it seems desirable to exhibit the drawings (except Fig. 6, which is unnecesary) attached to the specifications, as follows:

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Fig. 1 shows the separators in cross-section of the armature. C is no part of the separator; B is one of the lamina; A is the flat portion of the separator; and a is one of the ribs set up upon it. Fig. 2 is a face view showing the separated sections of the armature and the separators in place. These two figures illustrate the separators when used in the form of armature wherein the periphery is entire, and on the surface of which the conducting wire is wound. The other figures are of toothed, or Pacinotti, style of armature wherein the core is in regular spaces recessed at the periphery, and so, of course, the rings or lamina of which it is composed. The wire is wound in the spaces between the teeth. In all the figures, b shows the holes in which the rivets are to be driven to attach the separators to the laminæ. It will be observed that in Figs. 4, 5, and 7, the separators consist only of flat pieces riveted to the laminæ. And it will be noticed also that in Figs.

1 and 3 the ribs of the separators extend outwardly to the periphery of the core, in both forms of the rings, the smooth and the toothed peripheries. The claims which it is alleged are infringed are these:

"(1) A laminated armature core built up in sections, and separators attached to the lamina between two consecutive sections, as and for the purpose described.

“(2) In an armature core the combination with sections built up of laminæ, of separators consisting of ribs of metal between said sections, and in contact with adjacent lamine whereby ventilating space is afforded between the inner and outer surfaces of said core, as described."

"(4) In a toothed armature core built up of laminated sections, separators consisting of ribs extending outwardly from the teeth on one of said sections to the corresponding teeth on the adjacent section, whereby said sections are mutually supported and air passages radial to the center of said core afforded, as and for the purpose specified.

"(5) An armature core consisting of laminæ arranged side by side and separators attached to certain of the lamina to form a ventilating space or spaces in the core.

"(6) An armature core consisting of layers of laminæ built up in sections or bundles, and pronged or skeleton separators attached to an outside lamina of each of said sections, whereby ventilating space is provided between adjacent sections, as described."

"(8) In an armature a sheet or lamina having teeth or projections for the reception of the armature coils or armature conductors, and metal separators riveted or otherwise secured thereto, said separators extending toward the points or free ends of said teeth or projections."

A very comprehensive, and, as we think, extravagant, interpretation is put upon these claims by the complainant's expert in laying the foundation for his comparison with earlier structures. It is stated that the. invention is principally intended for dynamo-electrical machines in which the armature revolves inside the stationary magnetic field. But it is further stated that it is also applicable if the machine is one in which the field is the revolving member and the armature is stationary. And this is apparent. But it will conduce to clearness to discuss the subject by reference to a machine organized in the first of the forms mentioned, though some of the characteristics of separators required in this first form might not be so important in the other, a circumstance resulting from the fact that in one form they are in a rapidly rotating organization while in the other that body is stationary. If this had been an original invention, first devised to secure ventilation of the armature by fixing open spaces in its organization through which currents of air could be carried, it must have been admitted that it exhibited a new and very useful device to supply a need that had been recognized in the art as a serious one. But it was not. It followed in the wake of numerous patented inventions intended to meet this need, and the defendant contends that no new idea is shown by the Reist patent, but only the mechanical skill which one conversant with the subject, and with what had already been pointed out as means for meeting the difficulty, might be expected to supply. It is contended that Reist discovered no new principle or mode of operation which is represented by the means he proposed, and that the means which he did propose effect no new result, but are the equivalent of former constructions operating in the same way, more skillfully designed perhaps, but carrying forward an old idea in better forms. This defense makes

it necessary to find out what had already been discovered and known in the art when this patentee brought out his method of constructing separators in armatures to effect their ventilation. We cannot undertake to critically analyze and exhibit in detail all the former constructions of separators shown in tne patents found in the record, but shall confine ourselves to a few which seem to us most relevant and important; though there are many others in the record which illustrate the general idea of the proper method of providing for ventilating the armature, that is, by separating the core into sections and putting separators between them, to maintain the spaces for currents of air. We may preface what we have to say by stating that the necessity, or at least the great advantage, of ventilating the cores of armatures had been known and appreciated several years before Reist gave his attention to it, and that the method of doing this by dividing the core into parallel sections and interposing between them separators to hold them apart, and provide space for the circulation of air in the body of the core had been devised, and for several years practiced, in the manufacture of such machines.

In 1881, one Brown obtained a patent for improvements in armatures which showed them built up of sections of soft iron bars, a method of construction since superseded by the use of thin laminæ instead of bars. The need of ventilation was the same as in the later construction. For the purpose of securing it, Brown employed plates of sheet metal, such as Russian sheet iron, secured to the outer bar of each section. These plates were provided with flanges turned up at right angles from each edge of the plate. The edges of the flanges did not bear directly upon the opposite bar, as in the Reist patent, but contacted with the corresponding edges of a similar plate riveted to the opposite bar. These plates separated the sections and formed an air chamber. The sides of the plates were radial to the central line of the armature. Several openings were made in the flanges on both sides of the plates through which the air from the central chamber was drawn through the armature, some of it passing directly through the periphery and part sidewise through an opening in the bars, and thence out through the radial chamber. And in his third claim, he includes these plates to form, as he says, "an air chamber which communicates with the external air, whereby, during the revolution of said 'armature, air will be drawn into said chamber and circulate into and through the air spaces of the bobbins or sections."

In November, 1883, patent No. 288,051 was granted to Giles for an invention, the sole purpose of which was to provide for the formation of air spaces in the core of armatures. Instead of dividing the laminæ into bundles or sections, he attached separators upon "one or both" sides of each lamina (he calls them "rings") "oblique ribs uniformly arranged and spaced, and inclining away from the direction of the armature," a feature shown in other patents, evidently designed to facilitate the draft of air. The ribs were attached to the "rings" and extended the entire width of them, but were insulated from them to "prevent electrical currents from traversing the core." All his

claims call for these ribs as means for separating the rings and affording ventilating spaces.

On March 3, 1884, R. E. B. Crompton obtained a patent in England for an invention of improvements in dynamo electric machines which was patented also in Belgium in 1885, and in the United States August 7, 1888, where it was numbered 387,343. He states that the objects of his invention are, referring to the armature:

* Third, the arranging of the winding and its insulation so as to allow of the free access of a ventilating current of air to every part of its surface, and the providing this ventilating current by simple means."

His preferred form of armature is built up of annular rings of soft sheet iron mounted on the dove-tailed radial spokes of the spider. Corresponding dove-tails are made in the inner edges of the laminæ. Fig. 2 shows one of the rings (or "laminæ," or "washers," as they are indiscriminately called in the art) of the Gramme form of core. FIG. 2

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The rings are composed of sections arranged in parallel form with ventilating spaces between the sections. In building up the armature, he lays the rings one upon another, properly insulated, and "at regular intervals as shown at g, gl, g2, g3, etc., the washers may be spaced from one another by strips of material, i, i, which must also insulate them from one another and thus leave radial ventilating channels or space." He says "radial" ventilating channels or spaces. Reference to his drawing shows that the separators and spaces are in a general sense radial, but not quite so, for they are turned backward somewhat (having regard to the motion of the armature indicated by the arrow) so as to promote the exit of the air, as in other constructions heretofore referred to. And, he adds cautions applicable to the plain ring core and to the toothed ring core to so construct them and form the winding as not to obstruct the ventilating spaces. At this point, we remark upon a matter which will be referred to later. In his drawings Crompton shows in Fig. 2 in cross-section a smooth armature and the spacing ribs, i, i, extending to its periphery. In Fig. 4 he shows a toothed armature, but the spacing-ribs are not shown. And a question is whether in the latter form he extends the ribs along the teeth. Inasmuch as he had extended them in the smooth form to the surface, and the teeth are so thin and fragile as to require a supporting separation to prevent their collapsing into the ventilating space, and no other way of preventing it is suggested, we think it is a reason

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