Combining Applications For Filing In The U.S.

1985 – Article
IDEA: The Journal of Law and Technology, Volume 26, No. 1 (1985), pages 25-32

One of the most troubling issues that continues to face patent practitioners outside of the U.S. is the requirement of U.S. law that a patent application be filed in the name of the inventor. The problem is relatively simple when only one inventor exists, but uncertainty increases rapidly as multiple inventors or inventive entities1 are involved. Typically, the question of joint inventorship is raised when practitioners outside the United States are faced with inventions that are closely related, but are described in separate patent applications listing separate inventive entities in the country of origin. The foreign practitioner often desires to combine the separate applications into a single application for filing in the U.S. Yet, care must be taken to ensure that the combination of foreign applications into a single U.S. application is proper. Otherwise, a shadow of doubt may be cast over the validity of any patent that may issue. Understanding when such a combination of foreign applications into a single U.S. application is proper, requires an understanding of the U.S. law on joint inventorship. Unfortunately, the U.S. law itself is somewhat nebulous. However, there are trends that can be used to suggest guidelines for indicating when it is proper to combine foreign applications of different inventive entities into a single U.S. application.

The U.S. Patent Code states:2


When an invention is made by two or more persons jointly, they shall apply for patent jointly and each sign the application and make the required oath, except as otherwise provided in this title.

In the past, there has been no clue in the statute as to exactly what the relationship must be between two inventors for them to be considered "joint" inventors. Certainly, if the inventors work together and openly cooperate with one another in developing the invention sought to be patented, there is no doubt that the parties are joint inventors. But what are the outer limits, the minimal levels of communication required of joint inventors?

This question has been partially answered by an amendment to the patent statutes,3 signed into law by President Reagan on November 8, 1984. This amendment adds the following language to 35 U.S.C. 116:


Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.

This amendment codifies the well known concept, that it is not necessary that the entire inventive concept should occur to each of the joint inventors or that the two must physically work together on the invention.4 The inventors need not work on the invention at the same time or in the same place, but they must collaborate.5 What is sufficient collaboration? Certainly, if there is absolutely no communication between two parties, they cannot be considered joint inventors, as some form of communication of information from one joint inventor to the other is absolutely required. This communication need not be a face-to-face, two-way dialog but can amount to one inventor simply reading the work of the other. It is therefore possible to have joint inventorship where a second inventor reads the work of a first inventor after the first has died.

In the course of their collaboration, the joint inventors must share some knowledge of the general goal or end toward which they were working.6 Furthermore, all inventors must contribute something of importance to the joint invention. Sufficient importance of the contribution is generally assumed when the question of combining foreign applications is considered, as the assumption is made that each foreign application contains something of significance or it would not have been filed. Nevertheless, some discussion of the contribution of the various joint inventors is warranted.

The amended law makes it clear that the contributions of each inventor need not be of the same type or amount, codifying prior case law.7 Thus, one joint inventor may have contributed a major portion of the invention while another may have contributed only a small portion. This principle was clearly set out in the leading case of De Laski & Thropp Circular Woven Tire Co. v. William R. Thropp & Sons Co.8


In order to constitute two persons joint inventors, it is not necessary that exactly the same idea should have occurred to each at the same time, and that they should work out together the embodiment of that idea in a perfected machine. The conception of the entire device may be due to one, but if the other makes suggestions of practical value, which assisted in working out the main idea and making it operative, or contributes an independent part of the entire invention, which is united with the parts produced by the other and creates the whole, he is a joint inventor, even though his contribution be of comparatively minor importance and merely the application of an old idea.

Although this case is old, it has been widely accepted and is currently cited9 as the standard by which this question should be measured. A similar point was made in Monsanto Co. v. Kamp:10


Each needs to perform but a part of the task if an invention emerges from all of the steps taken together .... The fact that each of the inventors plays a different role and that the contribution of one may not be as great as that of another, does not detract from the fact that the invention is joint, if each makes some original contribution ....

However, the contribution of one of the inventors must not be a separate and distinct invention. This principle is mentioned in De Laski, citing earlier precedent in Worden v. Fisher11 and Stewart v. Tenk.12 Thus, if the "contribution" of one of the inventors is really a distinct and independent inventive component, rather than an intrinsic element of the basic invention, that inventor is not considered a joint inventor, but, rather, an independent and unrelated inventor. Similarly, a person who is a sole inventor of one independent element of a combination is not necessarily a joint inventor of the combination,13 as the inventorship of the combination is a separate and distinct issue from the inventorship of the component element.

Given this background, let us assume that a foreign practitioner is considering filing in the United States. He has two applications disclosing closely related technology filed in his native country. The inventors named in these two applications are different, yet they both work together in the same department and are both engaged in research in the same technical field. There is no doubt that they have engaged in communications with one another, at least to the extent that one has reviewed the work of the other prior to inventing the subject matter of his own application. The practitioner reaches the conclusion that under applicable U.S. law he can combine the two native applications into a single U.S. application based upon the law of joint inventorship in the United States. If the practitioner is correct, no problem arises. But let us assume further that he is wrong -- that the two applications do not disclose a single joint invention, but two independent inventions.14 A single U.S. application is filed in good faith as the foreign practitioner is not aware of his error. What happens?

If the U.S. Examiner determines that two independent and distinct inventions are claimed, he issues a restriction requirement. The response to the restriction requirement must include an election of one of the two claimed inventions. If the restriction requirement is made final, the foreign practitioner will be aware that his combination of the two foreign applications into a single U.S. application was an error because no joint invention was made. A change in inventorship is required, and can be routinely made as provided for under 35 U.S.C. 116 and 37 C.F.R. 1.48, which requires a petition, a declaration by each inventor, a fee, and consent of any assignee. Such a change must be made diligently and without deceptive intent.15

If the discovery that separate inventions exist takes place after a patent issues, correction may still be made, although with more difficulty. A reissue application may be filed and then divided into two separate applications, each claiming one invention and naming only the proper inventor.16

The courts have consistently held that there is a strong presumption that the inventorship in an issued patent is correct. If a change must be made, 35 U.S.C. 256 assures that:


The error ... shall not invalidate the patent in which such error occurred if it can be corrected as provided in this section.

The courts have followed this principle for nearly a century.17

Error in misjoining the inventors is not by itself, an indication of fraud.18 However, fraud may be present in other related acts, such as misjoining the inventors to avoid the discovery of a published article by one of the inventors or any similar ulterior motive.

Whether a desire to avoid incurring multiple filing fees could in itself be adjudicated an "ulterior motive" is, of course, a critical question presently unanswered. However, absent an ulterior motive, simple misjoinder will not be construed by the courts as fraudulent, and hence no loss of patent rights results.

A related issue is whether a foreign applicant can claim priority in a single U.S. application based upon two or more priority documents, each naming only some of the inventors named jointly in the U.S. case. Although this precise question has not been conclusively answered, such a claim for priority appears to be proper.19 The Manual of Patent Examining Procedure (MPEP) at 201.15 directs:


If there is disagreement as to inventors on the certified copy, the priority date should be refused until the inconsistency or disagreement is resolved.

This is not to say that it should be finally refused, only that the inconsistency must be resolved. Thus, if the Examiner questions that difference in inventorship between the various priority documents and the U.S. application, the circumstances should be explained to him, leaving the Examiner free to question or accept the determination of joint inventorship. Bruce Collins20 has criticized this requirement and set forth solid reasons why the Patent and Trademark Office is without legal or logical basis for a requirement of consistent inventorship. It should be noted that Monsanto21 includes a holding that joint inventorship existed in the U.S. even though a corresponding Canadian application did not indicate joint inventorship.

Where the foreign priority document is not in English, a very common situation, it is possible that the Examiner may not realize there is a difference between the inventorship indicated on the priority documents and that in the U.S. Application. In such cases advising the Examiner of the difference in inventorship would eliminate any possible argument as to lack of candor in this regard.

Of course, from a practical point of view, the claim for priority is examined carefully by the PTO only when the priority date is relied upon to overcome a reference. This occurs in a small percentage of cases. Thus, while priority documents naming different inventors may clearly suggest that several foreign applications with different inventive entities have been combined into a single U.S. application, it is quite rare that the U.S. Examiner raises a question as to the propriety of the combination.

Although now finally rectified by the above quoted amendment to 35 USC 116, the history of the troubling issue of joint contributions to the claims is interesting. A question has long existed as to whether the invention defined in each and every claim of an application filed in the name of joint inventors must be jointly invented. The traditional view was that each claim in an application must recite an invention made by the named inventor or inventors, and that any claim directed to an invention made by a different inventive entity (even if it is one of the named joint inventors) should be presented in a separate application. This rule is traceable through De Laski22 and Stewart.23 As recently as 1964, the CCPA said, in a footnote in In re Sarett:


It should be clear that the patent could not legally contain a claim to Sarett's sole invention under existing law because it would not have been the invention of the joint patentees.24 (emphasis in original.)

The Patent and Trademark Office Board of Appeals followed the Sarett "rule" as recently as 1981.25

Gradually a number of courts began to move away from the Sarett "rule." The U.S. District Court for the Eastern District of Virginia said in regard to the meaning of "joint" as requiring contributions by all inventors to each claim:


Neither the statute nor any rule of the Patent Office ... cited to the Court provides such a restrictive meaning of the term "joint."26

This approach was followed in 1980 by the District Court for the Northern District of Alabama,27 which reasoned that if one could change the inventorship for all claims of a patent, it should certainly be possible to change the inventorship for only some of the claims. The basis for this conclusion was the A.F. Stoddard & Co. v. Dann,28 and the liberal construction of the statutory law with respect to another inventorship issue contained therein. The district Court for the District of Minnesota, in 1981, reached the same conclusion in Vekamaf Holland B.V. v. Pipe Benders, Inc.29 The District Court for the Central District of California cited Vekamaf in support of its similar decision in Rosemount Inc. v. Beckman Instruments.30

Thus, the District Courts established a trend away from the traditional approach adopted by the CCPA and accepted by the PTO Board of Appeals. The conflict between these different points of view has finally been put to rest by the recent amendment to 35 U.S.C. 116.

This change in the statutory law will eliminate some of the problems encountered in the past in combining multiple foreign applications into a single U.S. application. Where a proper combination of foreign applications produces in a U.S. application, an inventorship including inventors who have contributed to all of the claims, the U.S. application is clearly proper and need not be divided under the amended law. A "proper" combination occurs where joint inventorship is established. Although the amended law does not permit applications disclosing two independent inventions to be combined, it does permit combinations of several foreign applications of differing inventorship when the foreign applications disclose various embodiments of a single inventive concept.

The same recent statutory amendment includes several other changes, some of which also relate to problems of inventorship.

One such change relating to inventorship was made in 35 U.S.C. 120, which now allows an application to be considered a continuing application where the inventive entity in the continuing application is not exactly the same as in the parent.31 Thus, when an examiner determines that an application includes two independent inventions and requires restriction, a subsequent divisional application will be considered proper even if the restriction requires a different designation of inventorship in the divisional and parent cases. The amendment removes the possibility of losing an earlier filing date when two foreign applications are wrongly combined into a single U.S. application, and then later divided with a change in inventorship.

Another of these changes adds a new sentence to 35 U.S.C. 103, preventing the rejection of a claim on subject matter which qualifies as prior art only under subsections (f) or (g) of section 102, when the subject matter and the claimed invention were commonly owned at the time the invention was made.32 This change is essentially a codification of the recent General Motors-Toyota decision.33 It prevents material developed by one part of a corporate research team from becoming prior art against the final invention produced by the team. It is especially meaningful to organizations involved in research, and may occasionally prevent the rejection of an application or invalidation of a patent by one member of a research team on prior art produced by a fellow team member.

In summary, inventors can be considered "joint" inventors in the U.S. as long as there is collaboration among them, they work toward the same general goal, and each contributes to a particular invention, rather than to a separate, independent invention. Furthermore, the risk of error in combining separate foreign applications into a single U.S. application, under the proper circumstances, is now less severe in view of the recent amendments to the patent code of the United States.


Reprinted with permission. First published in IDEA: The Journal of Law and Technology, Volume 26, No. 1 (1985), pages 25-32.


*.Mr. Maier is a partner in the firm of Oblon, Fisher, Spivak, McClelland & Maier, and Mr. Gnuse is an associate in the same firm.



[1].Jorda, "Inventorship Discrepancies Between Foreign Priority and U.S. Applications," 7 A.P.L.A. Q.J. 145 (1979)

[2].35 U.S.C. 116, (1982).

[3].Public Law 98-622 Section 104(a). Patent Law Amendments of 1984, Pub. L. No. 98-622, §104(a), 98 Stat. 3383, 3384.

[4].Monsanto Co. v. Kamp, 269 F. Supp. 818, 824, 154 USPQ 259, 262 (D. D.C. 1967).

[5].S. W. Farber, Inc. v. Texas Instruments, Inc., 211 F. Supp. 686, 690, 135 USPQ 394, 398 (D. Del. 1962).

[6].Pointer v. Six Wheel Corp., 177 F.2d 153, 157-8, 83 USPQ 43, 47 (9th Cir. 1949).

[7].Payne v. Natta, Primo and Mazzanti, 172 USPQ 687, 694 (PTO Bd. Int., 1971).

[8].De Laski & Thropp Circular Woven Tire Co. v. William R. Thropp & Sons Co., 218 F. 458, 464 (D. N.J. 1914), aff'd 226 F. 941 (3rd Cir. 1915).

[9].In re Certain Steel Rod Treating Apparatus, 215 USPQ 237, 255 (U.S. International Trade Commission 1981).

[10].See supra note 4.

[11].Worden v. Fisher, 11 F. 505 (E.D. Mich. 1882).

[12].Stewart v. Tenk, 32 F. 665 (S.D. Ill. 1887).

[13].See supra note 4.

[14].Note that the traditional approach of the CCPA has been to determine inventorship on a claim-by-claim basis. Under this standard, inventorship may change as the claims are amended. See In re Sarett, 327 F.2d 1005, 140 USPQ 474 (CCPA 1964). This problem has been eliminated by Public Law 98-622, which states that inventors need not contribute to each claim.

[15].37 CFR 1.48 (1984).

[16].35 USC 251. Ex parte Scudder, 169 USPQ 814 (PTO Bd. App. 1971).

[17].Butler v. Bainbridge, 29 F. 142 (S.D. N.Y. 1886).

[18].In re Sarett, 327 F.2d 1005, 1010 n. 7, 140 USPQ 474, 479 n.7 (CCPA 1964).

[19].In re Schmidt, 293 F.2d 274, 130 USPQ 404 (CCPA 1961).

[20].Collins, "The Significance of Inventorship Determinations for Foreign and Domestic Inventors," 7 A.P.L.A. Q.J. 117 (1979).

[21].See supra note 4.

[22].See supra note 8.

[23].See supra note 12.

[24].See supra note 18.

[25].Ex parte Martin and Spector, 215 USPQ 543, 544 (PTO Bd. App. 1981).

[26].SAB Industri AB v. Bendix Corp., 199 USPQ 95, 104 (E.D. Va 1978)

[27].Racal-Vadic, Inc. v. Universal Data Systems, 207 USPQ 902, 929 (N.D. Ala. 1980).

[28].A.F. Stoddard & Co. v. Dann, 564 F.2d 556, 195 USPQ 97 (D.C. Cir. 1977).

[29].Vekamaf Holland B.V. v. Pipe Benders, Inc., 211 USPQ 955 (D. Minn. 1981).

[30].Rosemount Inc. v. Beckman Instruments, Inc., 569 F. Supp. 934, 218 USPQ 881 (C.D. Cal. 1983), aff'd 727 F.2d 1540, 221 USPQ 1 (Fed. Cir. 1984).

[31].See supra note 3 at §104(b).

[32].See supra note 3 at §103.

[33].General Motors Corp. v. Toyota Motor Co., Ltd., 212 USPQ 659 (6th Cir. 1981), cert. denied, 215 USPQ 95 (1982).