(dissenting). This is an appeal from a decree for the appellees, dismissing- a bill asking for equitable relief tinder section 4918. The appellant seeks to have the Vreeland patents, No. 1,239,852, granted September 11, 1917, for a receiver for electrical impulses, and No. 1,245,166, granted November 6, 1917, for method of transmitting and receiving high-frequency impulses as interfering under this statute with appellant’s Fessenden patent, No. 1,050,441, granted January 14, 1913, for electrical signaling apparatus, and patent No. 1,050,728, granted January 14, 1913, for method of signaling. It is sought by this action to annul claims 1 to 8, inclusive, of the Vreeland *474patent, No. 1,239,852, as interfering with claims 2, 3, 4, and 29 of the Fessenden patent, No. 1,050,441; also, the suit seeks to establish that claims 9 to 28 of the Vreeland patent are invalid, for the reason that they are disclosed in the Fessenden patent and the then state of the art. The appellant also seeks to have decreed that all of the claims of Vreeland’s patent, No. 1,245,166, are interfering with claims 10, 11, 12, 13, and 14 of the Fessenden patent, No. 1,050,728. The patents in suit all involve wireless systems in the art of telephony and telegraphy.
Under section 4918 of the Revised Statutes1 the appellant may maintain, as a person interested, this action against the owner (as the defendant is) in equity for the interference with the appellant’s patent by reason of the grant of the Vreeland patents to Vreeland. The court has the power to adjudge and declare either of the patents void in whole or in part, or inoperative or invalid in any particular part of the United States, according to the interest of the parties in the patent or the invention patented. General Chemical Co. v. Blackmore (C. C.) 156 Fed. 968. Therefore, if the patents interfere or cover the same invention, this action is maintainable. It is therefore essential, as in infringement suits, that interpretation or construction of the patents be considered in determining whether there is such interference. It is necessary to examine the disclosure of the patents themselves, and to ascertain what was the state of the art at the time of the prior grant. Thus, one of the patents involved may have but a single claim that interferes; all other claims may be different in terms or degree. Under such circumstances, the court has power to declare such claim void because of the interference with the rival patentee. Bird v. Elaborated Roofing Co., 256 Fed. 366, 167 C. C. A. 536.
When' a patent is granted by the Patent Office, the grant must have protection against interference, for in a single invention there can be but a single patent. Under, this statute, the court’s decision only affects the actual interest before the court, and does not prejudice any stranger to the litigation owning an interest in either patent. The rule of construction in a proceeding of this kind forbids the outstanding of two grants of patents for the same invention. Such a situation is created where the same inventive thought is described in two patents in quite different language. -It was this view which has led to a great number of decisions which find infringement or lack of infringement, irrespective of the presence or absence of the literal response to the language of the claim. Benjamin El. Co. v. Northwestern Co., 251 Fed. 291, *475163 C. C. A. 444; Geoghegan v. Ernst, 256 Fed. 671, 168 C. C. A. 64; Tostevin-Cottie Mfg. Co. v. Ettinger, 254 Fed. 435, 166 C. C. A. 66; Silver Co. v. Sternau & Co., 258 Fed. 448, 169 C. C. A. 464.
The inquiry in the case at bar is: Did the inventors make the same contribution to the sum of human knowledge as was said in Bird v. Elaborated Roofing Co., supra? If so, the claims are for the same invention, notwithstanding the lack of similarity in language or scope or number of elements. In this study, the authorities clearly establish that the court is not limited to consideration of claims alone, but “the invention * * * covered hy the claims is to be ascertained * * * by a proper construction thereof” giving to each claim its due scope and effect. Simplex Ry. Appliance Co. v. Wands, 115 Fed. 517, 53 C. C. A. 171. To determine the particular discovery for which each of the patents was granted and the point from which the inventor started, in order to know what the invention is that supports the patent, the courts have even taken recourse to expert testimony as to the technical terms and the difference between or the identity of the devices. Palmer v. Lozier, 90 Fed. 732, 33 C. C. A. 255. It has also examined the knowledge of the art and the position of the patents in that art. It may even apply the doctrine of equivalents, in order to determine what is a patentable invention covered or attempted to be covered by each of the patents. If there is no claim to the same invention made as to one of the patents, there is no interference; but, when each patent has a claim directed to that invention, there is an interference, even though the claims of the rival patents are not identical in terms and the number of elements, or in scope.
An issue of fact is thus presented upon all the evidence, whether they are of the same effective scope, and this issue cannot be determined upon the face of the two documents, but both are to be construed in the same way and upon like evidence as a patent in an infringement suit or in a suit to recover royalties under a license agreement. Logically, this is necessary in order to determine whether the two patents granted cover a single invention. If so, that which is granted later must give way to the earlier grant. If, under the evidence here disclosed, the system and methods disclosed by the Fessenden and Vreeland patents, as they are understood by the skilled worker in the art, and in view of the then state of the art, are the same essentially and electrically, there is only one invention, no matter how the claims may be phrased. If such a conclusion is reached, this court is empowered, under the terms of the statute, to go so far as to find the Vreeland patents void in whole or in part. It is true that, when two patents are pending in the Patent Office at the same time, and both of them granted there is a prima facie presumption that each was properly granted. Boyd v. Tool Co., 158 U. S. 260, 15 Sup. Ct. 837, 39 L. Ed. 973. Nevertheless,, if both patents are for the same things as far as any inventive qualities are concerned, only one of them can stand. Brooks v. Sacks, 81 Fed. 403, 26 C. C. A. 456. The claim of the appellant is that the patents of Fes-senden and Vreeland do exactly the same thing and in the same way.
The receiver patents are for continuous, or substantially continuous, waves; such waves are manifested in the indicator by combining the re*476ceived wave with the electrically produced oscillations of slightly different frequency. These produced beats are equal to the difference between the frequency of the received wave and the locally generated oscillations. The receiver controls the pitch of the signal note by controlling the frequency of the oscillations. They amplify the signal strength. Thus, both have the ability to select the signals from a given station to the substantial exclusion of signals from other stations. As I examined the claim of the appellees, it is that the Fessenden patent illustrates one kind of an indicator, in which the beat signal is made manifest, while the appellees illustrate indicators which are manifestly different. The transmitter patents utilize the continuous wave with the beats receiver or heterodyne. The transmission of the signals is effected by changing the frequency .of the transmitted continuous wave, thereby producing in the heterodyne receiver a different beat note between the parts of the wave indicating thé signals and the parts indicating the interval between signals. As one, for tire signal parts, the transmitted wave can be of the frequency differing from the frequency of the electrically generated oscillations which are combined together, thus giving in the receiving telephone, the beat note of a pitch to say 1,000 vibrations per second, and whereas for the periods between the signals, the transmitted wave'can be made to substantially co-exist in frequency with that of the electrically generated waves or oscillations, thus producing no beats giving periods of oscillations of the telephone, or made of such frequency as to give a different pitch note from that of the signal.
As to the claims, the appellees say that Fessenden’s are generic in character, and are based upon a structure involving the keeping'of the current separate; that the Vreeland claims are specific in character, and are based on a structure involving bringing the two currents together— that is, combining the two currents in one circuit. It contends that Fessenden used for his receiving apparatus a device known as a dyna-mometer telephone with two separate coils. With an ordinary telephone receiver, or so-called magnetic'telephone, an electromagnet having a single coil transversed by telephone currents is located in close proximity to a diaphragm, which vibrates in accordance with the varying magnetic effect. It is claimed that with the dynamometer telephone there is no combined current, but two fiat coils, known as “pancake” coils, each in a separate circuit, one of said coils being mounted on a telephone diaphragm and the other stationary, whereby variations in the magnetic pull between the two coils will take place when they are traversed by the telephone currents.
It is argued that Fessenden never conceived of Vreeland’s invention of combining the two currents in one circuit, and that therefore he used this type which is an inefficient separate coil dynamometer. It is contended that the signal and local currents are separate, transversing separate circuits, and that they separately transverse the separate coils which produce mechanical action. Appellee’s claim is that Fessenden’s patent is known as a mechanical heterodyne. The appellant claims that there is an induction and therefore there is no separation of currents; but there is the interaction of currents, and but one circuit. It is the *477matter of control of current or the circuit that counts. It may be that Vreeland, by the receiver which he has used, has accomplished the result of an improved indicator o E the current; but this does not make his invention different, if there is in appellant’s an interaction of currents and but one circuit.
Fessenden, in his patent, says that it may operate by interaction of either electrostatic or electromagnetic fields, and that a variety of forms of receiving devices may be employed saying that those which he illustrates are convenient and desirable. The indicator illustrated is old in the art, operating with an electrical magnetic field. It is called a dynamometer telephone, but it is apparent that an induction of one current to the other takes place at the two coils marked 8 and 10 in Fig. 3. Vreeland admits that, even with the arrangement shown in Fig. 5 of his receiver patent, either the received signal impulse or locally generated oscillations alone would produce an electrostatic field between the jilates of the condenser telephone. Claims 26, 27, and 28 of this receiver patent include the electrostatic field excited by local oscillations and another field of different frequency excited by signal impulse. It thus appears that, where the local voltage is produced, the static telephone has two existing interacting fields whose resultant moves the diaphragm.
Is there any essential difference between the static and the dynamom-eter telephone, as far as the fields are concerned? In either case, the heterodyne, the currents of different frequency, are applied, to the instrument, and there is a resultant field in the telephone, due to the interaction or superposition of the effects of the energies supplied by the two currents. The substitution, therefore, of the static telephone for the dynamometer telephone, is not a difficult, but a simple, matter to one skilled in the art. Vreeland admits that there is no distinction between the fields and currents or between superposition or combination of currents and the interaction of fields. This is illustrated in Figs. S, 9, and 10 of the Vreeland original drawings and in his original specifications. The same contention that is advanced here by the appellee, that the Fessenden claims are for a generic invention, while Vreeland’s are for a specific invention, was presented in General Chemical Co. v. Blackmore (C. C.) 156 Fed. 968, and an interference was held to exist, because the only reasonable interpretation of Blackmore’s alleged generic claims rendered them an obscure description of the specific discovery. In the case at bar, a combined or beat current necessarily exists in the Fessenden circuits, and since the indicator or detector is operated by that beat current, a proper interpretation of Fessenden’s claims becomes a dearer description of Vreeland’s alleged specific invention. It is thus apparent that the patents in suit (Fessenden’s, No. 1,050,441, and Vrecland’s, No. 1,239,852) contain claims in common and are interfering patents. The substance or invention is one and identical; the only difference is in the manner of its statement.
The transmitter patents (Fessenden, No. 1,050,728, and Vreeland, No. 1,242,166) involve the use of the continuous wave transmission with the beats reception or heterodyne; the essential novelty consisting in transmitting the signals by changing the frequency of the continuous *478wave whereby there'is produced, in the heterodyne receiver a different beat effected by the waves Constituting the signal characters than by those constituting the intervals between signal characters. The systems of the Fessenden and Vreeland patents do exactly the same thing. Both make use of a continuous wave; both produce the signal characters by changing the frequency of the wave; and both receive with a beats receiver. The analogy is so close between these patents that the sole difference between certain of the rival claims is that Vreeland claims say the change of frequency of the transmitted wave is made abruptly; whereas in the Fessenden claim the word “abruptly” is not used. So far as the physical things are concerned, this attempted definition has to do merely with a particular kind of generator used for producing the transmitted wave. Fessenden illustrates a transmitting generator, a high frequency alternator, a form which he had previously patented, and to which he would by nature be partial. Vreeland illustrates a vacuum tube, an alternator of the form which he had previously patented, and to which he was naturally partial. Both types of generators were old in the art and were used for producing continuous waves.
To sustain the appellees’ position, it is necessary to limit the Fessen-den disclosure of a transmitting generator to a high-frequency alternator illustrated, and then so that change of frequency can be effected only by varying the speed of the roto of that alternator, and that this cannot be done abruptly.. But in practice, with the use of the appellant’s generator, the change of frequency is effected with sufficient rapidity to transmit, and there is sufficient “abruptness” to accomplish the purpose of the invention. Fessenden does not limit, by his illustration, a particular form of generator, but mentions other forms of generators.
Does the change of wave frequency by the alternator illustrated by Fessenden become “abrupt”? And then does Fessenden disclose a sending generator of a type the frequency of whose generated waves can be changed in precisely the way disclosed by Vreeland, and therefore equally as abrupt as with the Vreeland generator? Vreeland cannot confine Fessenden to the use of the high-frequency alternator illustrated. The method in issue contemplates only a slight change of frequency; Fessenden saying a matter of one-fifth of 1 per cent., while Vreeland a minute variation during the frequency of these (transmitted) waves. Fessenden in no way limited himself to the use of the high-frequency alternator, and changing its speed by means of rheostat or the like. He disclosed, among a number of transmitting generators to be used, one of exactly the same kind as illustrated by Vreeland. He says in his patent:
“In the practice of my invention I prefer the use for sending and means for producing continued radiation, which may be, for example, the high-frequency generator having the characteristics described in patent No. 707,737, or the means described in patent No. 706,742,”
And again:
“It is preferred to use a high-frequency alternator, or any other suitable device for producing unintermittent oscillations, as, for example, a device *479opej'ating by direct current, with or without discharge gap, as described in tetters patent No. 706,742.”
In patent No. 1,050,441 he says:
•‘J prefer to use a high-irequeiicy alternator, or a mercury lamp producing oscillations whoso frequency is maintained constant — that is to say, not intermittent — by automatic means.”
It is apparent to me that the specific transmitting generator used by Fessenden, to wit, the high-frequency alternator, with a slight change of speed necessary to produce the necessary change in the signal note, can be made with sufficient rapidity to transmit signals nearly as fast as they can be recorded and received by the aural receiver, and that, therefore, the change of frequency of the transmitted waves is made abruptly. Speaking from the result accomplished by each as disclosed by the record, I do not think that there is much more than a change of phraseology in the specifications and claims used by Vreeland. Fes-senden was the first in date of application and of grant as to the receiver and transmitter patents, and protection should be accorded to him.
I think that claims 1 to 8, inclusive, of Vreeland patent, No. 1,239,-852, interfere with claims 3, 4, and 29 of Fessenden’s patent No. 1,050,-4-41, which was granted first, and that tlie Vreeland patent, No. 1,245,-166, are interfering claims with claims 10, 11, 12, 13, and 14 of Fessen-den patent, No. 1,050,728. The subject-matter is technically the same. The invention discloses the same idea. Similarities and differences do not depend on mere names or words used to describe them, or immaterial matters by which they may be distinguished. Glue Co. v. Upton, 97 U. S- 3, 24 E. Ed. 985. In determining similarities and differences, the courts are not governed by the names of things, but they must look to the devices and contrivances in the light of what they really are and what office or function they perform and how they perform it.
For these reasons, I think the decree below should be reversed.
“Sec. 4918. Whenever there are interfering patents, any person interested in any one of them, or in the working of the invention claimed under either of them, may have relief against the interfering patentee, and all parties interested under him, by suit in equity against the owners of the interfering patent; and the court, on notice to adverse parties, and other due proceedings had according to the course of equity, may adjudge and declare either of the patents void in whole or in part, or inoperative, or invalid in any particular part of the United States, according to the interest of the parties in the patent or the invention patented. But no such Judgment or adjudication shall affect' the right of any person except the parties to the suit and those deriving title under them subsequent to the rendition of such judgment."