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The above excerpts will be more readily understood when it is appreciated that in prior machines of this type there were separate bearings for the two ends of the armature axle, each bearing (through the bracket in which it was located) being separately attached to the frame. In consequence more work was required to adjust them in assembling the machine in the shop, so as to fasten the bearings and other parts in proper position. It was sometimes necessary to take the machine apart, for cleaning, repairs, or other purposes and when reassembling was undertaken by persons, not as skillful mechanics as those who made it, there was a chance that the bearings might not be replaced precisely where they should be. The substitution of a single "cradle" in which both bearings are located for two separate brackets, each carrying a bearing, is the fundamental improvement above referred to, which overcame, measurably at least, the difficulties enumerated. Referring to the drawings, of which Fig. 2 represents an end view of the machine, the specification proceeds:
"3 represents the cradle or frame having bearings 4 and 5 [5 only is shown in this Fig. which is looked at end-on] in which the armature is adapted to be mounted. The bearings are preferably cast integrally with the cradle, but may be put on separately in any suitable manner. The bearings should be provided with renewable bearing boxes. The cradle may also be provided with other bearings-such for instance as 6-to support a counter-shaft to be used in connection with the armature-shaft through any suitable transmitting device. The form of the cradle is such that it will surround the frame of the machine as illustrated in Fig. 4 or will be adapted to be clamped between the parts 1 and 2 as illustrated * in Fig. 2. The latter form is the one which I prefer, and in this instance the cradle, or at least such parts of it as are clamped between the parts of the magnet-frame, should be of suitable magnetic conducting material, as such parts form part of the magnetic circuit.
"In order to facilitate the construction of the machine, I provide suitable faces for the cradle, against which the parts of the magnet-frame are adapted to be clamped. When the cradle is made to surround the magnet-frame as shown in Fig. 4, the frame may be provided with suitable supports [projecting from the sides of the frame]. * * * It will be understood that the invention is not limited for use with any particular type of machine and may be used with a machine having its magnet-frame composed of one or more parts.
I therefore desire it to be understood that I do not limit myself to the precise construction and arrangement of parts herein shown. It will be seen that the parts of the magnet-frame may be reversed with relation to the cradle or bearing-frame-that is, the part shown as the lower part in the drawings may be used as the upper part-and the machine thus reversed can then be readily attached to the ceiling."
The claims in controversy are:
"(1) In a motor or generator, the combination with the magnet-frame of the machine, of a cradle adapted to support the armature of the machine, and be supported by the magnet-frame, substantially as described."
"(3) In a motor or generator, the combination with the magnet-frame, of a cradle having a plurality of permanently mounted bearings for the armatureshaft said cradle being clamped to and supported by said magnet-frame, sub.stantially as described."
The only defense which need be considered is anticipation alleged to be found in certain so-called Thomson-Houston motors running elevators in the city of Boston. The date of installation prior to Burke's date of invention is conceded, and one at least of them is still running. The machines with which Burke seems to have been especially concerned were small motors, such as are used for electric fans, ventilators, etc.; but, as seen above, he did not confine himself to any type, and is free to show infringement in any machine, however ponderous, which embodies his invention with such modifications only as ordinary shop-skill would be required to make in order properly to install a heavier machine than the one which patentee more particularly describes. A like rule must be applied in considering anticipating devices.
The following sketch represents the Thomson-Houston Motor:
1 is the cradle which supports the armature in its bearings. 4, 4, 4, 4 is one part or one-half of the magnet-frame wound with field coils, A, A. 5, 5, 5 is the other half or part of the same, wound with field coils B, B. Between these two parts of the magnet-frame is clamped the armature cradle by bolts, 6, 6, 7, 7, which may be compared with the bolts, x, x, y, y, of Fig. 2 of the patent. Referring to Fig. 2, it is apparent that, except for the purpose of locating it upon some base or support, the lower half of the magnet-frame (2) might be made precisely of the same shape as the upper half (1),
and it would fulfill all the functions which are assigned to it. The devising of appropriate means to connect it with its support is within the range of common shop expedients, the drawing shows an extension downward below the dotted line, and terminating in feet (12, 12) adapted to rest on the floor or base, and which may be secured thereto if it be desirable to secure the machine in some particular location, instead of moving it from place to place. The combination shown in the patent would be as efficient, if there were no extension below the dotted line and no feet, and the lower part of the magnet-frame were bedded in a concrete base. No other support for the magnet-frame than the extended feet is shown, nor any further support for the cradle than the magnet-frame itself. Apparently the drawing contemplates a machine of such a size that good workmanship. in installation would not require the supplemental aid of additional supports. The man who had to install the ponderous ThomsonHouston motor, however-it weighs more than a ton-had to provide much sturdier supports for such a mass of metal; and he accomplished it in this way. Instead of extending the ends of the lower-half of the magnet-frame downwards so as to form legs integral with the frame, he built up heavy metal posts, 8, 8, from a metal base, 9, and on those posts rested the ends of the lower half of the magnet-frame, cutting recesses in the tops of the posts so that the heads of bolts, 5, 5, could enter therein and the lower-half of the frame rest squarely on the posts. Apparently to distribute weight and to meet the strain of the heavy cradle where it projected beyond the frame, he built up four additional posts two shown in the drawing (2, 2) and two just like them on the other side of the machine. It was convenient to secure the entire machine against any sidewise play by bolting the cradle frame into the tops of these posts, 2, 2, 2, 2. Probably there are a number of convenient shop devices which would have secured the same result by using the posts, 8. One or more dowel pins or upwardly projecting lugs on each post, 8, fitting snugly into holes in the lower half-frame would apparently have accomplished it; but the enormous weight of the Thomson-Houston machine called for extra strong fittings, and it may well have been important to use the four posts instead of the two.
Of course mere modifications in the details of setting-up the combination of the patent in the place where it is to do its work are immaterial unless they affect in some way the operation of such combination. A mere casual inspection of the model of the ThomsonHouston motor, which the complainant put in evidence, and which is correctly shown in the above drawing, shows that it has the several parts, performs the functions, and appears to be a substantial reproduction of the combination of the patent.
The various objections which complainant makes to its being considered an anticipation may next be examined.
1. It is suggested that the "armature of the Thomson-Houston motor cannot be magnetically centered as in the Burke patent. To adjust the position of the armature frame the machine would have to be separated from its base, and all its parts separated from each other. This would
preclude operation of the machine while finding the magnetic center. In Burke's device, it is only necessary to slide the armature cradle a little one way or the other while the machine is running." This suggestion presupposes the assumption that the cradle, where it is clamped between bolts, x, x, y, y, has some lateral play. Whether x and y indicate separate bolts, or merely the two ends of the same bolt, is not quite clear; in either event, however, lateral play of the cradle could be secured by making the hole in the cradle into which any x, y bolt passed larger than the diameter of the bolt, or extending it, at right angles to the axis of the bolt, by slots. This theory of lateral adjustment, however, is evidently an afterthought-and, in view of the language of the patents, not a particularly ingenious one-of the expert witnesses. The claims contain no reference to it, and there is not to be found in the specification a single phrase, or even a single word which suggests the faintest intimation of such a function. Fig. 2 supra shows the cradle clamped by bolts between the two halves of the magnet-frame, but it gives no indication as to the size of the holes in the cradle which those bolts enter. Fig. 3, however, shows the cradle, and the holes shown on either end of the bearing faces, 7 and 8, are evidently the holes into which the x, y bolts enter. There is nothing to indicate that they are large enough or of such elongated shape as to admit of any lateral movement of the cradle. When, moreover, we examine Fig. 4, which shows a modified form, in which the cradle surrounds the frame, instead of being clamped between its two halves, and the model, which both sides agree represents the Fig. 4 variety, we find that the cradle is so fixed in place with lugs or dowel pins as to preclude any lateral movement. Finally, such capacity for lateral movement is one of the things which Burke was seeking to avoid. In assembling one of these motors, it is, as the evidence shows, a delicate piece of work to determine the magnetic center, and to locate the armature and its cradle properly in relation thereto. It requires the skill of one experienced in the art of the electrical engineer. When that is done, and the cradle (with its armature) is secured in its proper place, and the machine assembled and installed, it is desirable that it may live out its life of usefulness without having to call in the special skill which first assembled it, because it will be operated by persons who are not expert electrical engineers. The whole scheme of the patentee was to devise a combination of parts, which, when taken apart and reassembled, would always fit together, so as to secure at all times "perfectly-aligned bearings, ** not liable to displacement by use of the machine or other causes." Burke expressly refers to liability to displacement due to re-assembling the machine after the parts have been once separated, and the evidence shows that it is necessary sometimes to take the machine apart in order to clean it. It is manifest that if the cradle were so arranged as to play laterally when the bolts, x, y, were loosened up, the chances of distortion from the magnetic center would be greater even than they were with the old double bracket structure. If the function now first suggested were incorporated in the machine which the specifications and drawings describe, it would wholly defeat the fundamental object of the inventor, as he himself states it.
2. It is suggested that the Thomson-Houston motor "does not have what is in any proper sense an armature cradle." It is not perceived, upon examination of the brief and the testimony, precisely what this statement means. Manifestly the motor has a fran. or cradle, cast or forged in a single piece with bearings hollowed out in it to receive the axle ends of the revolving armature, and by reason of the fact that it is a single piece of metal the bearings are at all times in perfect alignment with each other. The axle ends are held in place by caps. The armature with its axle ends still in the bearings, may be removed simultaneously with the cradle which supports it. Why 1, 1 is not in every proper sense an armature cradle we are at a loss to understand. 3. It is suggested that the armature cradle is not "removable either practically or in any sense equivalent to the operation of the Burke cradle." Examination of the brief and testimony shows that this criticism is really to the effect that the Burke machine may be more readily taken apart than the Thomson-Houston motor. It would be a sufficient answer to such criticism to point out that nowhere in the claim or in the specifications is the facility of removability of parts declared to be a feature of the invention, except that it is said to be "desirable that the armature be capable of being removed from the machine without being taken out of its bearings." But, as is apparent on inspection of the Thomson-Houston model, they can be removed together, although, by reason of the additional supports required by the great weight of the motor, more bolts would have to be removed, and more power expended in lifting and turning before that result can be accomplished.
4. It is suggested that the "armature cradle is not reversible either practically or in any sense equivalent to the operation of the Burke cradle." It would unduly expand this opinion to show that this criticism is unsound, that, in fact, the parts of the Thomson-Houston magnet-frame may be reversed with relation to the cradle, and that-the size being reduced to admit of such a method of installation—it may be attached to the ceiling. It is a sufficient answer to the criticism to note that this reversibility of parts, although referred to in the specifications, is not made an essential part of the invention; that it is obtained by a particular construction and arrangement of parts; that the patentee expressly states that he does "not limit [himself] to the precise construction and arrangement of parts herein shown"; and that neither of the claims sued upon contains anything to indicate that it is intended to cover only reversible machines. A machine which should be in all other respects within the terms of the patent would be an infringement of these claims, even though, by reason of some detail of construction or arrangement of parts, it was not capable of being reversed and attached to a ceiling.
5. It is suggested that the Thomson-Houston motor is not within the claims, because the armature cradle is not supported upon the field magnet; the language of the first and third claims being "supported by the magnet-frame," and "clamped to and supported by said magnetframe," respectively. This objection is hypercritical, and is based on the assumption that the posts, 2, 2, are the true supports of the machine, supporting the cradle frame which itself supports the parts of