said tape transmitter to any one of said channels, means operable over the selected channel for initiating the operation of the transmitter and means for automatically stopping the tape transmitter at the completion of the transmission of each group of message signals.

Appellee's reissue application discloses an automatic telegraph system in which messages may originate at any one of a number of outlying stations, and may be transmitted to a central station, where they are recorded on perforated tape. The messages thus recorded will include, first, the address in duplicate, second, the body of the message, third, an answer-back cut-in signal code, fourth, a signature, consisting of the address of the sending station, and fifth, an end-of-message signal.

When the complete message has been recorded at the central station, the calling line is released and mechanism becomes effective which first compares the duplicate addresses and, if they are found to correspond, utilizes the address to select, successively, the channels by which a connection is made with the station called. If this station is idle, the message is transmitted and, when the answer-back cut-in signal is reached, the answer-back mechanism becomes effective to record the address of the calling station and the address of the called station. Those addresses are then retransmitted to the calling station to show that the message has been received. The system includes various details which are not involved here and need not be considered. It also includes other details which can best be discussed in connection with specific issues raised by counsel for appellants.

Counsel for appellee contends that appellants are estopped by judgment from raising the question of the operativeness of appellee's telegraph system because of a decision in a prior interference (No. 68,426) involving the application (No. 585,582, filed January 8, 1932) of Robert F. Dirkes and Vernon R. Kimball (assigned to the Western Union Telegraph Company), the Robert F. Dirkes being the same Robert F. Dirkes involved in interferences Nos. 79,163 and 79,166, and appellee's original application, No. 651,737, which matured into patent No. 2,193,967.

Interference No. 68,426 was terminated in December 1935 by the Examiner of Interferences awarding priority of invention of the subject matter defined by the counts there in issue to Kleinschmidt by virtue of a concession of priority of invention executed on behalf of the parties Dirkes and Kimball and the Western Union Telegraph Company. The interference involved four counts, which define a method of transmitting a telegraph message.

The method there involved comprised, substantially, converting a message into a so-called "control-form," in which form the message was in two parts (an address part and a remainder part), then, as

stated in count 4 of that interference, "combining under control of the address part of the message a plurality of part-paths to form a complete path to the place of destination of the message, and thereafter transmitting both parts of the message over the path under control of the form."

In the instant case, the Board of Interference Examiners held that appellants were estopped by judgment from raising the question of the operativeness of appellee's disclosure because of the decision in interference No. 68,426, the board stating that, although no decision. had been brought to its attention which was directly in point, a somewhat analogous situation existed in the case of Waller v. Coe v. Brown, 193 O. G. 511, 1913 C. D. 187. The board apparently relied, however, upon the decision in the case of Ex parte Robinson, 32 USPQ 165.

Although the board held that appellants were estopped from raising the question of the operativeness of appellee's disclosure, it, nevertheless, considered that question and held that appellee disclosed an operative system.

In the Waller case, supra, the Commissioner of Patents held that the assignee of the Waller application was estopped from raising the question of the Coe and Brown applications containing new matter because it had failed to present a proper and timely motion to dissolve.

In the case of Ex parte Robinson, supra, it appears that the party Robinson had been involved in an interference (involving four counts) with one Barnebl. Robinson had conceded priority of invention to Barnebl as to the subject matter of counts 1, 2, and 3, and the Examiner of Interferences awarded priority of invention of the subject matter defined by those counts, and also that defined by count 4, to Barnebl. Thereafter, in an ex parte prosecution of the Robinson application, the Primary Examiner rejected the claim in the Robinson application which constituted count 4 in the interference proceeding on the ground that it was unpatentable over count 3 of the interference. On appeal, the Board of Appeals held that as Robinson did not move to dissolve the interference on the ground that the claim constituting count 4 of the interference was not supported by the Barnebl disclosure he was not in a position to raise that question in an ex parte prosecution of his application.

[2] The decisions in the Waller and Robinson cases, supra, obviously, are not controlling of the issue in the instant case.

Counsel for appellee argues that the Board of Interference Examiners was right in holding that appellants were estopped from raising the question of the operativeness of appellee's disclosure; that it was the duty of the common assignee (the Western Union Telegraph Company) to have raised that question in the prior interference (No.

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68,426); and that as the Western Union Telegraph Company failed to do so, appellants are now estopped to raise that question in the instant interference. In support of his views, counsel cites several cases among them being: In re Mason, 25 C. C. P. A. (Patents) 873, 94 F. (2d) 220, 36 USPQ 337; Avery v. Chase, 26 C. C. P. A. (Patents) 823, 101 F. (2d) 205, 40 USPQ 343; United States Rubber Co. v. Coe, Commissioner of Patents, 146 F. (2d) 315, 64 USPQ 100.

The foregoing cited cases relied upon by counsel for appellee have to do with the application of the doctrine of estoppel in accordance with the provisions of rule 109 of the Rules of Practice in the United States Patent Office. The issue here presented does not involve the provisions of that rule. Accordingly, the principles announced in the decisions in those cases are not applicable to the issue in the instant case.

We have examined the decisions in other cases cited by counsel for appellee in support of his views, and find that they clearly are not in point. Accordingly, we deem it unnecessary to discuss them here.

It is conceded by counsel for appellee that the joint parties (Dirkes and Kimball) in interference No. 68,426 could not have made any of the claims constituting the counts in the instant interference. Furthermore, at the time the decision was rendered in the prior interference, appellants had not filed their application which matured into the patent here involved, nor, so far as the record here discloses, was the common assignee the owner of any application which disclosed the invention here involved and which might have been included in that interference.

The law with respect to estoppel by judgment was fully considered by the Supreme Court in the case of Cromwell v. County of Sac., 94 U. S. 351, 352, where it was stated:

there is a difference between the effect of a judgment as a bar or estoppel against the prosecution of a second action upon the same claim or demand, and its effect as an estoppel in another action between the same parties upon a different claim or cause of action. In the former case, the judgment, if rendered upon the merits, constitutes an absolute bar to a subsequent action. It is a finality as to the claim or demand in controversy, concluding parties and those in privity with them, not only as to every matter which was offered and received to sustain or defeat the claim or demand, but as to any other admissible matter which might have been offered for that purpose.

But where the second action between the same parties is upon a different claim or demand, the judgment in the prior action operates as an estoppel only as to those matters in issue or points controverted, upon the determination of which the finding or verdict was rendered. In all cases, therefore, where it is sought to apply the estoppel of a judgment rendered upon one cause of action to matters arising in a suit upon a different cause of action, the inquiry must always be as to the point or question actually litigated and determined in the

original action, not what might have been thus litigated and determined. Only upon such matters is the judgment conclusive in another action. [Italics not quoted.]

The principles announced in the Cromwell case, supra, have been followed consistently. See Nesbit v. Riverside Independent District, 144 U. S. 610,618; New Orleans v. Citizens' Bank, 167 U. S. 371, 386; United Shoe Machinery Corporation et al. v. United States, 258 U. S. 451, 458, 459.

Although the parties in interference No. 68,426 and in the instant interference are the same, and appellee's original application was involved in the prior interference, the application which matured into appellants' patent here involved was not in the prior interference, nor did the application of Dirkes and Kimball disclose the invention involved in the instant interference. Furthermore, from an examinatiton of the counts involved in the prior interference and those herein issue, it is evident, we think, that the causes of action involved in the instant interference differ materially from those involved in the prior interference. The difference is not merely one of scope or breadth, but the counts in the instant interference are for distinct and separate inventions from those defined by the counts in the earlier interference. Accordingly, the decision in interference No. 68,426 is res adjudicata only as to the issues actually litigated and determined therein, and not as to the issues which might have been, but were not, litigated and determined. As the question of the operativeness of appellee's disclosure was not raised or determined in that interference, the decision therein does not estop appellants from raising that question in the instant interference.

In the instant case, the board did not pass upon the question of estoppel in pais with regard to the issue of the operativeness of appellee's disclosure, and, under the circumstances of this case and in view of the record before us, we deem it unnecessary to discuss that question here. Accordingly, we shall proceed to consider the question of the operativeness of appellee's disclosure.

Although appellants formerly advanced many grounds of inoperativeness of appellee's system, they rely here only on those designated D. A, and B. Accordingly, the remaining grounds need not be considered.

Ground D, which is discussed at greatest length by counsel for appellants, relates to the tape transmitter mechanism. The intended operation requires that this mechanism shall advance the tape a short distance until the duplicate addresses have been compared, that it shall then retract the tape substantially to its former position, and finally feed the entire message through the device. The arrangement is such that three means will be required, one for each of the forward

movements and one for the retracting movement. The means for the retracting movement only is fully disclosed by appellee.

Appellee's application states that the first forward movement is a "stepping" produced by a designated shaft on the shaft of a feed wheel which moves the tape forward. Although the mechanism which produces this stepping movement is not completely illustrated, no means being shown for connecting the aforesaid shafts, it obviously would be understood from the disclosure to be a pawl and ratchet type of device, and since it is necessary that such a device shall permit the tape to be retracted, it is evident that the pawl must not remain in engagement with the ratchet, but must be withdrawn at the end of each forward step.

The Primary Examiner and the Board of Interference Examiners were of opinion that one skilled in the art could readily produce a device that would operate so as to permit the tape to be retracted. The Primary Examiner referred to three patents (York et al., No. 1,298,622, and McKay, No. 1,609,955, issued prior to the filing of appellee's application, and Morton et al., No. 1,904,164, issued subsequent to appellee's filing date) as showing pawl and ratchet mechanisms suitable for such purpose.

Counsel for appellants properly point out that the pawl and ratchet devices in the patents to York et ak and McKay are so designed that they will not permit retraction, while the Morton et al. patent is not available to appellee since it issued after his original application was filed.

Evidently the tribunals of the Patent Office were of opinion that one skilled in the art could, without the exercise of the inventive faculties, modify the pawl and ratchet devices disclosed in the patents available to appellee so as to permit the tape in appellee's disclosure to be retracted. In other words, as we understand it, it was the view of the Patent Office tribunals that one skilled in the art could modify the prior art pawl and ratchet devices so that the pawl would engage the ratchet only during the forward movement of the tape.

There is nothing of record tending to indicate that it would require anything more than mechanical skill to modify the prior art pawl and ratchet devices so as to make them available for use in appellee's system.

Although the feeding means, which is to move the tape forward after its retraction, is not illustrated in appellee's reissue application, its construction would appear to present no difficulty, it being only necessary that the tape be advanced step by step in conformity with the operation of the tape sensing mechanism. It is clear what movements are intended to be given to the tape by appellee, and both the Primary Examiner and the Board of Interference Examiners were of