Case: JO. C. CALHOUN, JR., AND ESTHER C. YOUNG, EXECUTORS OF THE ESTATE OF NIELS A. CHRISTENSEN (DECEASED) v. THE UNITED STATES
Abbreviation: Calhoun v. United States
Decision Date: 1964-12-11
Docket Number: No. 432-55
Citation: 168 Ct. Cl. 663
Volume: 168
Reporter: United States Court of Claims Reports
Court: United States Court of Claims
Jurisdiction: United States
Parties: JO. C. CALHOUN, JR., AND ESTHER C. YOUNG, EXECUTORS OF THE ESTATE OF NIELS A. CHRISTENSEN (DECEASED) v. THE UNITED STATES
Judges: Before CoweN, Chief Judge, LaRamore, Dureee, Davis and ColliNS, Judges.
Pages: 663–692

Head Matter:
JO. C. CALHOUN, JR., AND ESTHER C. YOUNG, EXECUTORS OF THE ESTATE OF NIELS A. CHRISTENSEN (DECEASED) v. THE UNITED STATES
[No. 432-55.
Decided December 11, 1964]
Albert B. Teare for plaintiffs.
Henry Van Arsdale, with whom was Assistant Attorney General John W. Douglas, for defendant.
Before CoweN, Chief Judge, LaRamore, Dureee, Davis and ColliNS, Judges.

Opinion:
Per Curiam :
This case was referred to Donald E. Lane, a trial commissioner of this court who, under the order of reference, submitted his findings of fact and recommended conclusion of law in a report filed on July 22, 1963. Exceptions to the commissioner's report were filed by the defendant, briefs were filed by the parties and the case was submitted to the court on oral argument of counsel. Since the court is in agreement with the opinion and recommendation of the commissioner, it hereby adopts the same as the basis for its judgment in this case as hereinafter set forth. Therefore, the court concludes that claim 5 of United States Letters Patent No. 2,180,795 is valid, that the invention covered by said patent claim was used by defendant without authorization of the patent owner, and that plaintiffs are entitled to recover reasonable and entire compensation for such unauthorized use. Judgment is entered for plaintiffs to this effect with the amount of recovery to be determined pursuant to Buie 47(c) (2).
OPINION OF COMMISSIONER
This is a patent suit under the provisions of 28 U.S.C. § 1498, for the unauthorized use and manufacture by and for the United States of a patented invention. The subject matter of this case concerns a packing construction disclosed in United States Letters Patent 2,180,795, granted to Niels A. Christensen on November 21, 1939. Said Niels A. Christensen was at the time of his death in 1952 a citizen of the United States and the sole owner of the legal title to said patent. Plaintiffs, Jo. C. Calhoun and Esther C. Young, are citizens of the United States and are the duly appointed executors of the estate of said Niels A. Christensen.
The patent disclosure and the patent claim in suit are described in the accompanying findings of fact. The several issues of law involved are discussed in the following comments.
The invention of the Christensen patent appears, at first impression, to be of a simple nature involving only the placing of an O-ring seal in a reciprocating piston and cylinder combination. As such, this first impression would lead one to believe that this invention must have been previously suggested in the art, or at least have been such as would be obvious to one having ordinary skill in the art. Upon closer scrutiny, however, it becomes apparent that the Christensen disclosure solves a perplexing problem and makes a significant contribution to the piston and cylinder sealing art. The Christensen disclosure provides that the depth of the groove in which the O-ring is mounted must be such as to compress the O-ring into a somewhat ellipsoidal shape when the cylinder and the piston are assembled. The width of the groove must also be greater than the diameter of the cross-section of the O-ring but less than twice that diameter. By these requirements Christensen provided a sealing O-ring which sealed the assembled piston and cylinder combination during the reciprocal movement of the piston, and which retained its effectiveness for long periods. This last-mentioned characteristic resulted from the width of the groove being great enough to allow the O-ring to be slightly kneaded or worked during the strokes of the piston. If the width of the groove were restricted to the same size as the diameter of the cross-section of the O-ring, the O-ring would have been confined against any working or kneading and would have a resulting shorter life as an effective seal. Prior to Christensen's disclosure, it had been found that when O-rings were placed in grooves having large widths the ring would roll and twist, resulting in reduced life of the ring and in leakage. By limiting the width of the groove to less than twice the diameter of the cross-section of the O-ring, Christensen controlled the amount of roll of the O-ring and eliminated the twisting problem while at the same time retaining the advantages of the slight movement of the O-ring within the groove. Prior to Christensen's disclosure, the construction usually employed in piston packing for sealing hydraulic fluids was of the compression seal type using a gland nut which could be tightened to compress a packing into sealing engagement with the moving parts. This construction caused a relatively high degree of friction which resulted in low efficiency due to the objectionable amount of power required to overcome the friction. In addition, this construction required the added weight of adapters and adjustment nuts, and required occasional manual disassembly of the cylinder and adjustment of the compression on the packing to maintain the proper sealing.
When Christensen disclosed his invention to the defendant, it was immediately subjected to tests and was adopted to supersede the old style of packing. In addition, the inven tion of the patent in suit went into widespread use in private industry. Between 1946 and 1956 the patentee, and his successors in interest, received royalties from industrial users on 261,938,168 units. The defendant took a license under the patent in suit in 1942 for $75,000. This license was terminated in 1952. The defendant has continued to use the invention, and admits that if claim 5 of the patent is valid, it is infringed by defendant's continued use.
The defendant alleges that the Christensen patent is invalid in view of one or more of some 16 patents which are described in detail in the accompanying findings of fact. In general, these patents show various types of packings and various uses for O-rings. None of the cited patents teach a reciprocating piston and cylinder combination utilizing a seal comprised of an O-ring mounted in a groove which is wider than the cross-sectional diameter of the O-ring but narrower than twice that diameter. The defendant alleges, however, that it does not require invention for one to select parts from certain of the cited patents and to combine them with selected parts of certain of the other cited patents to produce a packing like that of Christensen. This allegation is based on 35 U.S.C. § 103, which reads in part as follows:
A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.
Thus it is defendant's position that the differences between certain of the cited patents and the Christensen invention are such that would be obvious to one having ordinary skill in the art in view of the structures of certain of the other cited patents. This position is not supported by the facts. Assuming that by combining selected parts of the various cited patents one could construct a packing construction like that of the Christensen patent, there is still no teaching in the art or the cited patents that such a packing would provide an effective seal for a reciprocating piston and cylinder combination. The evidence indicates that this teaching was not the type which would have been obvious to one having ordinary skill in the art. Indeed it was thought, by those skilled in the reciprocating piston and cylinder art at the time of Christensen's invention, that an O-ring which was not compressed by a gland nut or the like would twist and leak if mounted in a groove having a width larger than the cross-sectional diameter of the O-ring. That the Christensen teaching was not considered obvious at the time of the invention is further supported by the fact that both the defendant and the commercial industry quickly adopted the Christensen invention and were willing to pay substantial royalties for the privilege of using it, and by the fact that the defendant admits it is imitating the invention to such an extent that it has no defense to the charge of infringement if the patent is valid and not misused. See Kurtz v. Belle Hat Lining Co., 280 Fed. 277 (2d Cir. 1922), Otto v. Koppers Co. Inc. 246 F. 2d 789 (4th Cir. 1957), 114 U.S.P.Q. 188; Unilectric, Inc. v. Holwin Corp., 243 F. 2d 393 (7th Cir. 1957), 113 U.S.P.Q. 242.
The defendant has previously taken á license under the patent which it now contends is invalid. In addition, the District Court for the Northern District of Ohio, Eastern Division, has held, in a separate suit,, that the Christensen patent is valid over prior art similar to that cited in the case at bar. While neither of these factors is controlling as to the issue of validity, they both serve to strengthen the presumption of validity which normally attaches to an issued patent. Dueber Watch-Case Mfg. Co. v. Robbins, 75 Fed. 17 (6th Cir. 1896), and Georgia-Pacific Corp. v. U.S. Plywood Corp., 258 F. 2d 124 (2nd Cir. 1958), 118 U.S.P.Q. 122.
The invention of the Christensen patent is not anticipated by the cited patents either alone or in combination, and therefore the Christensen patent is found to be valid.
The defendant alleges that by granting licenses to the manufacturers of the unpatented O-rings, the patent owners attempted to use the patent to induce purchasers of the unpatented packings to purchase them from their licensees and thus to restrain competition in the unpatented packings. Defendant further alleges that the patent owners attempted to extend the patent monopoly beyond its lawful boundaries, and that such conduct constitutes misiise of the patent. The evidence does not sustain these allegations. The only evidence which the defendant has offered in support of its allegations of misuse are two agreements between Niels A. Christensen and Linear Incorporated. The first agreement is dated January 11,1946, and the second agreement, which is a supplemental agreement to the first agreement, is dated January 31, 1950. Pertinent portions of these agreements are set forth in detail in finding 23 and need not be reproduced here. In effect, these agreements provided the manufacturer of O-rings was licensed to make and sell O-rings for use in the patented construction, and the purchaser from the licensed manufacturer was licensed to use the Q-ring in accordance with the patent. In return, the licensor was to receive a royalty of one-fourth of a cent for each packing construction used. The supplemental agreement more clearly spelled out that the ultimate purchaser from the licensed manufacturer was to have a license to use the O-ring in the patented packing construction and that the licensed manufacturer was, in effect, collecting the 14-cent royalty from tire purchaser as agent of the licensor. A fair reading of the original agreement implies that these supplemental provisions were within the intent of the original provisions. Thus, the agreement as supplemented was substantially the same as the original agreement, and there is no need to consider the two agreements separately. The plaintiffs have submitted two documents showing that the patent in suit was placed on the Eegister of Patents Available for Licensing, along with an acceptable license form, in December of 1947, and that the patent in suit was advertised to the public for licensing in the Official Gazette of the Patent Office in March of 1948. By offering no evidence other than the two agreements, defendant has rested its case on the proposition that these license agreements in and of themselves constitute patent misuse. These agreements do not establish that there has been misuse. There has been no showing that the patent monopoly has been expanded or used to restrain trade. The mere fact that patent royalties are based on the price of an unpatented material does not in and of itself constitute patent misuse. See Hall Laboratories, Inc. v. Springs Cotton Mills, Inc., 112 F. Supp. 29 (W.D.S.C. 1953), 97 U.S.P.Q. 69, affirmed 208 F. 2d 500 (4th Cir. 1953), 100 U.S.P.Q. 6, and Binks Mfg. Co. v. Ransburg Electro-Coating Corp., 122 U.S.P.Q. 74, modified on other grounds, 281 F. 2d 252 (7th Cir. 1960), 126 U.S.P.Q. 318. Further, the fact that a license is given to use a patented device with the purchase of an unpatented device is not of itself patent misuse. See Sola Electric Co. v. General Electric, 146 F. Supp. 625 (N.D. Ill. 1956), 111 U.S.P.Q. 203. This is not a situation where it has been shown that there has been a refusal to license unless purchaser .buys the unpatented material, see Technical Tape Corp. v. Minnesota Mining & Mfg. Co., 143 F. Supp. 429 (S.D.N.Y. 1956), 110 U.S.P.Q. 260, affirmed 247 F. 2d 343 (2d Cir. 1957), 114 U.S.P.Q. 422, or that the rates charged for the license without purchasing the unpatented material are such as to create two classes of customers, one favored over the other in the purchase of unpatented material as in Urquhart v. United States, 124 Ct. Cl. 441, 109 F. Supp. 409 (1953), 96 U.S.P.Q. 96. The Urquhart case is particularly pertinent. In that case the patents covered a method and apparatus for producing a fire-extinguishing foam. The patent owners did not practice the invention themselves but licensed various manufacturers of unpatented foam-forming material. These licenses provided, in part, that purchasers of the unpatented material from the licensed manufacturers acquired a license to use the unpatented material in practicing the patented inventions. The patent owners also had a second form of license which was to be used to grant licenses directly to the consumers. The royalty rate in this second form of license was greater than in the first form' used for the manufacturing companies. This court held that the Urquhart patent licensing policy constituted misuse of the patents, explaining that anyone operating under a 'direct consumer license and purchasing the un- patented material from other sources would be required to pay a higher royalty than one who acquired a license by purchasing this material from an Urquhart-licensed manufacturer. The court went on to point out that by channeling trade in unpatented materials through their appointed manufacturer, the patent owners had enlarged the monopoly of the patents beyond their legal scope. The case at bar is clearly distinguishable from the Urguhart case, in that both the consumer license and the manufacturer license specify the same license rate. The consumer who desires to purchase the unpatented O-ring from an independent source and take a direct license may do so and still pay the same royalty that he would be required to pay through the licensed manufacturer. Thus the licensing policy used with the Christensen patent does not have the effect of controlling trade in the unpatented O-rings.
The licensing policy of the owners of the Christensen patent was within the scope of the patent grant and served proper business purposes. It relieved the patent owners from having to collect royalties from the users who purchased O-rings from the licensed manufacturers and at the same time allowed the licensed manufacturers to induce prospective purchasers to use the O-rings in the Christensen device, without subjecting themselves to liability as contributory infringers. In Calhoun v. State Chemical Mfg. Co., 153 F. Supp. 293 (N.D. Ohio, 1957) 115 U.S.P.Q. 120, involving the same patent and licenses here in suit, the District Court for the Northern District of Ohio, Eastern Division, in finding no misuse, said at page 302—
$ ‡ ‡ ‡
On the contrary, the fair implications of the evidence reflect an arrangement between the licensor and licensees by the terms of which the licensees were granted authority to actively induce their customers to use the- invention. Under the express terms of the license agreements the licensees were appointed agents of the licensor to collect royalties from those who purchase^ O-rings for use in the patented combination. Provision was also made in these agreements for a license from the patentee directly to the purchasers of O-rings, authorizing the latter to use the invention. By virtue of these agreements the patent owner was able-to collect substantial royalties from many "users of the patented combination, and the licensees were authorized to perform acts which, except for the consent of the licensor, would have subjected them to liability for contributory infringement under Par. (b) of Section 271 [of 35 TJ.S.C.]. It is unnecessary to determine whether the licensees did in fact actively induce their customers to use the invention. It is enough to say that it has not been shown that the plaintiffs misused the patent by granting the licenses in question.
It is recommended that the court find that Christensen patent No. 2,180,795 is valid, that claim 5 thereof has been infringed by defendant without authorization of the patent owners, and that the patent owners' right to compensation has not been barred by patent misuse.
FINDINGS OP PACT
1. This is a patent suit arising under the provisions of 28 TJ.S.C. § 1498 for reasonable and entire compensation for unlicensed use of an invention described and claimed in United States Letters Patent No. 2,180,795 entitled "Packing", issued November 21,1939, to Niels A. Christensen on an application filed October 2, 1937. This application is a continuation-in-part of an application filed December 29, 1933, entitled "Hydraulic Brakes", and issued April 26, 1938, as United States Letters Patent No. 2,115,383. The 2,180,795 patent will be referred to hereinafter as the Christensen patent or the patent in suit. The 2,115,383 patent will be referred to as the '383 patent. The patent in suit expired November 21, 1956. The plaintiffs, Jo. C. Calhoun, Jr., and Esther C. Young, are citizens of the United States and are duly appointed executors of the estate of Niels A. Christensen, deceased, the patentee of the patent in suit. Niels A. Christensen was, at the time of his death in 1952, a citizen of the United States and sole owner of the legal title in patent No. 2,180,795.
2. Counsel for the parties at pretrial agreed that the 'accounting issue, including evidence as to the number of articles procured and/or the value of the patented invention, or the extent of liability, if any, of the defendant, and the amount of reasonable and entire compensation, if any, due to plaintiffs on account thereof, will be deferred until after the entry of the order of the court on the issues of the validity and the alleged misuse of the patent in suit. Counsel for plaintiffs stated at pretrial that only claim 5 of the patent in suit is relied on for infringement. Counsel for defendant admitted that if claim 5 of the patent in suit is held valid, it has been infringed by defendant.
3. The patent in suit discloses a combination of a cylinder, a piston, and a packing element wherein the packing element is located in a groove in either the cylinder or the piston. More specifically, the patent teaches that if the dimensions of the packing element and the groove are properly related, the packing element will be continually kneaded or worked to enhance its life while operating as an effective packing for fluid medium pistons. Eight of the nine drawings of the patent are reproduced herein. Figs. 1, 2, and 5 are longitudinal sectional views of cylinders and pistons with packing rings associated therewith. Fig. 3 is an end elevation of the cylinder of fig. 2, and fig. 4 is an enlarged fragmentary vertical section through a piston and cylinder showing the packing ring associated therewith. Figs. 6 and 7 are enlarged fragmentary sections of a piston and packing ring showing the shape of the packing ring before and after insertion into a cylinder. Fig. 8 is an elevation of a circular packing ring.
4. The invention as illustrated in the patent embodies an annular groove 23 in either the piston 18 (fig. 1) or the cylinder 10 (fig. 5) together with an O-ring 26 or 28 which is positioned within the groove 23 and which operates to seal the gap between the piston and the inner wall of the cylinder. The O-ring 26 is a resilient elastic packing element normally having an approximately circular cross-section, while the groove 23 has a flat bottom portion which is spaced from the wall of the cylinder 10 by a distance less than the normal cross-section diameter of the ring. When the ring 26 is in the groove 23 in operative position, it is compressed by its contact with the cylinder. In the construction illustrated in figs. 1 through 5, the width of the groove 23 is greater than the cross-section diameter of the compressed ring by a fractional part of such ring dimension. As a result, the ring is compressed into a somewhat ellipsoidal cross-section and upon movement of the piston with respect to the cylinder, the ring partakes initially of a limited rolling movement. The specification of the patent points out that the particular fit of the ring in its operative position enables the packing ring to shift slightly within the groove, but not to shift enough to permit complete turning or rolling of the ring as would be caused by a wider groove permitting the ring to twist through 360 degrees. This shifting or partial twisting tendency of the ring works or kneads the material of the ring to keep it alive and pliable without the deleterious effects of scuffing which are caused by purely static sliding of packing material upon a surface. The life of the ring is prolonged by this slight kneading action. In another embodiment (figs. 6 and 7), the packing ring, when compressed between the cylinder and the piston, extends into the area separating the cylinder and the piston. When the piston is moved with respect to the cylinder, adhesive tendencies of the ring to the cylinder wall tend to twist the ring, creating an annular fin or projection 27 on the trailing side of the ring between the piston and cylinder wall. When the piston moves in the opposite direction, the packing ring tends to produce a fin on the other side of the ring. The patent claim in suit does not relate to the construction illustrated in figs. 6-7.
5. Prior to the Christensen patent disclosure, the construction employed in piston packing for sealing hydraulic fluids utilized U-cups, V-rings, and similar shapes, which were known as compression seals. These provided a structure wherein the packing material was positioned within a gland and tightened by a gland nut, thereby substantially compressing the packing and causing a relatively high degree of friction. The high friction required substantial power to operate the piston, resulting in low efficiency. Leakage could be overcome, if at all, by still greater compression with accompanying increased friction. Such prior constructions required the added weight of various adapters and adjustment nuts and required a disassembly of the packing gland to provide access to the interior of the cylinder. Adjustment of the packing was effected manually, with a wrench, by tightening the adjustment nut on a threaded stud. The particular significance of the Christensen invention lies in the finding that if an O-ring is mounted in such a manner that it will be slightly kneaded during the operation of a cylinder, it will retain its pliability, and the use of gland nuts and the like in the cylinder can be eliminated.
6. The weight and size of airplane parts are extremely important. Shortly after the patent in suit was granted, the invention was disclosed to aircraft manufacturers and to the research engineers at Wright Field. Exhaustive tests were made in the laboratory and in the field by the Government, and by private aircraft companies, particularly by the Chance Vought Aircraft Company. The Government immediately adopted the invention and standardized on a ratio of 1.33 between the axial dimension of the compressed ring and the width of the groove. The invention of the patent in suit superseded the old style of packing and, as a principle of sealing, has been very valuable to the Air Force. In addition, the invention of the patent in suit went into widespread use in private industry. Between 1946 and 1956 the patentee, and his successors in interest, received royalties from commercial sources computed on the basis of one-fourth of a cent per unit in the sum of $654,845.42. This is exclusive of the income received from the Government and represents royalties on 261,938,168 units.
7. On October 20, 1942, the Government entered into a license agreement with the patentee to use packing constructions embodying the invention of the patent in aircraft assemblies, and to have packing constructions made for it for aircraft use, in return for which the Government paid the patentee the sum of $75,000. The license extended to April 28, 1952, when defendant's right to a license expired. On May 15, 1952, the Government was notified by Christensen that further use of the invention would be an infringement of the patent. Subsequent to the date of termination of the license, and prior to the filing of the petition in this suit, the Government continued to use the invention and admits that claim 5 of the patent in suit is infringed if valid. Plaintiffs have elected to rely on claim 5 of the patent .in suit.
8. On June 28,1957, a judgment was entered by the United States District Court for the' Northern District of' Ohio, Eastern Division, holding claim 5 of the patent in suit to be valid and infringed. The decision is reported in 153 F. Supp. 293 and in 115 U.S.P.Q,. 120. An appeal from that judgment was taken to the United States Court of Appeals for the Sixth Circuit, but on April 14,1958, a Stipulation of Dismissal was filed and thereupon an order was entered by the Court of Appeals dismissing the appeal.
VALIDITT
9. Claim 5 of the patent in suit is set forth below in clauses to facilitate understanding the combination recited.
The combination of a cylinder and piston,
of a resilient elastic packing element therebetween having normally approximately circular cross-section,
of a groove having a flat bottom portion spaced from the cylinder wall a distance less than the normal radial dimension of the ring, whereby when the ring is in the groove in operative position, it is compressed into somewhat ellipsoidal cross-section, and the width of the groove being greater than the axial dimension of said compressed ring by a fractional part of said axial dimension.
The patent specification and drawings indicate the meaning of the term "radial dimension" is the cross-section diameter of the O-ring in the direction perpendicular to the longitudinal axis of the piston, and the meaning of the term "axial dimension" is the cross-section diameter of the O-ring in the direction parallel to the longitudinal axis of the piston.
10. Defendant contends that claim 5 of the patent is invalid in view of the following patents:
United States Patents
Patentee Patent No. Issue date
Gibson.- 80,066 July 21, 1868
Allison- 83,899 Nov. 10, 1868
Creuzb'aur- 88, 371 Mar. 30, 1869
Morley- 137,559 Apr. 8, 1873
Horton, et al_ 207,871 Sept. 10, 1878
Prager, et al_ 391,956 Oct. 30, 1888
Campbell- 1,653,985 Dec. 27, 1927
Bell- 1,739,537 Dec. 17, 1929
Durdin- 1,859,436 May 24, 1932
Rasmussen - 1,861,755 June 7, 1932
Bbitish Patents
Patentee Patent No. Issue date
Whieldon, et al_ 433 Feb. 14, 1870
Robertson_ 10,716 Oct. 14, 1899
Woodcock _ 12,253 Aug. 22, 1848
Hardy _ 20,584 Jan. 5, 1911
Parker_ 158,709 Feb. 14, 1921
Munro _ 213,142 Mar. 27, 1924
Each of the above patents has an effective date prior to the filing date, December 29, 1933, of patent '383 of which the patent in suit is a continuation-in-part, and hence have dates prior to any date to which the patent in suit is entitled. The Creuzbaur, Frager, et al., and Rasmussen patents were cited by the Patent Office during the prosecution of the application for the patent in suit and the British Parker patent was cited by the Patent Office during the prosecution of the application of the parent '383 patent. The Frager and Durdin patents, as well as the British patents to Whieldon, et ah, and Robertson, were considered by the District Court for the Northern District of Ohio in reaching its conclusion that the Christensen patent is valid.
11. The Gibson, Creuzbar, Morley, Horton, et al., Frager, Campbell, "Whieldon, Woodcock, Hardy, Parker, and Munro patents each disclose a rolling O-ring type of construction. The drawings of the Munro patent, which are reproduced herein, are illustrative of this rolling O-ring construction. Without going into the details of the Munro patent which relates to "Improvements in Self-Filling Reservoir Pens", it will be seen that the barrel or cylinder 1 has a plunger or piston 2 mounted therein, and that a loose rubber O-ring 3 is mounted between the inner surface of barrel 1 and the outer surface of plunger 2. When the plunger is pushed in or pulled out, the O-ring is caused to roll in the annular space formed between the barrel and the plunger. In the Munro construction the space is of sufficient length (this dimension is referred to as width in the Christensen patent) to allow the O-ring to make several complete revolutions during the stroke of the plunger.
12. The evidence shows that the use of a rolling O-ring packing results in a twisting of the ring which reduces the life of the ring and increases the tendency of the ring to leak. By limiting the width of the groove, Christensen controlled the amount of any roll of the O-ring and eliminated the twisting problem. The rolling O-rings disclosed in the prior patents noted in finding 11 above do not anticipate the invention defined in claim 5 of the Christensen patent.
13. The Gibson patent discloses a rotary valve water faucet which has an upper O-ring which functions, when the valve is turned to the valve-open position, as a stationary seal. A lower O-ring is seated in a wide groove having a width more than twice the diameter of the O-ring. This lower O-ring is of the rolling type discussed in findings 11 and 12 above. The upper Gibson O-ring is in a groove carried by the rotary valve stem. The groove is about the same width as the the axial width of the O-ring. Claim 5 of the Christensen patent requires that the groove width be greater than the cross-section diameter of the O-ring. Further, the Christensen patent teaches a packing which seals while the piston is reciprocating, whereas the Gibson O-ring seals only when the valve stem is stationary. Packings of the Gibson patent do not anticipate the invention defined in claim 5 of the Christensen patent.
14. The Allison patent relates to a hydrant. Referring to fig. 3 of the patent drawings, which are reproduced herein with reference characters added, it may be seen that an L-shaped water pipe G is fitted with a vertical extension F. A vertical water pipe D, having a rubber stopper on its lower end, is slidably mounted inside of extension F in such a manner that when pipe D rests on the vertical leg of L-shaped water pipe G, the rubber stopper seals the end of the water pipe. A plurality of openings b are arranged about the circumference of pipe D at a point slightly above the rubber stopper I. Water enters openings b when pipe D is raised sufficiently to unstop the end of water pipe G. A pair of annular grooves is provided about the periphery of pipe D, and a pair of O-rings, e and e' is mounted in these grooves. Waste passages d and d' are located midway between the annular grooves and extend through the walls of both extension F and pipe D. When pipe D is raised to unplug water pipe Gr, O-ring e closes the waste passages and prevents water from flowing out these passages while it is being drawn out at the spout. When pipe D is again lowered to its normal closed position, O-ring e prevents water from below from entering the waste passage, and O-ring e' prevents water in the waste passage from passing upward. The Allison patent construction differs from the disclosure of the patent in suit in that it is not a cylinder and piston-type pressure device but is merely a simple water valve formed by a pair of concentric pipes telescoped together. Even if extension F is considered to be a cylinder and pipe D is considered to be a piston, this arrangement does not anticipate the type of packing arrangement disclosed in the Christensen patent since there will be no pressure produced by packing rings e and e' of the Allison patent construction. Any pressure which might build up around O-ring e when the pipe D is lowered to its normal closed position, is relieved by the passage of water through openings b. The Christensen patent disclosure relates to cylinder and piston arrangement wherein the packing is subjected to and must withstand considerable amounts of pressure. The bottom of the grooves of the Allison patent valve construction appears to be arcuate rather than flat as set forth in claim 5 of the Christensen patent. The Allison patent disclosure does not anticipate the claim in suit.
15. The Bell patent relates to an elastic piston ring particularly adapted for pumps and so arranged as to be expanded by the fluid pressure when the piston is at work. Eeferring to figs. 1 and 2 of the patent drawings, which are reproduced herein, it will be seen that the piston ring 20 is generally rectangular in cross-section and has a pair of lips 22 directed toward each other and disposed annularly within the ring. The piston ring 20 is mounted in a groove in piston 10, with the groove being defined by flange 12, hub 11, and follower 13. The specification sets forth that the width of the ring must be less than the width of the groove. This difference in width is represented by the letter A in fig. 1 and the letter D in fig. 2. The Bell patent specification describes the operation of the piston ring as follows:
When the piston is being pulled to the right, the parts will be in the position shown in Fig. 1. Such a movement will cause the ring 20 to slide on the hub 11 toward the follower 13, thus leaving a space A between the flange 12 and said ring. In practice this space may be very slight and only sufficient to permit the fluid which passes by the flange to also pass through said space and under the adjacent lip 22 to the channel 23. The fluid being under pressure, will enter the pocket B in Fig. 1 under the flange 22 and compress the lip 22 thereof about the hub 11, so as to form a seal. The pressure of the fluid in the. channel 23 will also tend to expand the ring and cause it to seal against the surface of the pump cylinder. It will be seen that the fluid entering under the lip 22 on the right hand side of the ring will also enter the pocket C, but the pressure will be equalized on each side of the lip thereof.
When the plunger is pulled to the left, the ring 20 will shift to the position shown in Fig. 2, whereby a space D will be opened between said ring and the follower 18. The fluid will enter under the lip 22 adjacent said space and flow into the pocket E on the opposite side, thus sealing the lip 22 thereof against the hub 11. The ring will automatically seal itself during each stroke and will also prevent the fluid passing between the piston and the cylinder wall. The lips, of course, must be flexible enough to permit the operation and must not fit the head too tightly. If found desirable, the outer edges of the lips may be beveled at 21 and such bevels will aid the fluid in passing from the spaces A and D under said lips. The piston ring may be made in various sizes and may be applied to standard pistons without changing the construction of the same.
The Bell disclosure differs from that of the Christensen patent in that the Bell piston ring slides from one end to the other end of the groove during the strokes of the piston, whereas the Christensen O-ring makes a partial roll from one end to the other end of the groove. Further, the Bell piston ring relies on the hydraulic fluid to provide the sealing force, whereas the Christensen O-ring provides the sealing force from the mere compression of the O-ring between the wall of the cylinder and the wall of the piston. Finally, the Bell piston ring differs from the structure defined in claim 5 of the Christensen patent in that claim 5 requires a packing element- having a normally circular cross-section which is compressed into a somewhat ellipsoidal cross-section when in its operating position, while the Bell piston ring is normally rectangular in cross-section and is expanded rather than compressed when it is in its operating position. The Bell patent disclosure does not anticipate claim 5 of the Christensen patent.
16. The Durdin patent relates to seals for rotating shafts to prevent leakage of liquid from a pump casing at the place where the shaft passes through a wall thereof. Referring to fig. 1 of the patent drawings, which are reproduced herein, it may be seen that a casing 10 of a pump has a shaft 11 extending therethrough with an impeller 12 mounted thereon. A flanged retaining ring 14 is mounted loosely on the inward end of shaft 11 and bears against a washer 15 interposed between the ring and the wall of casing 10. The contacting faces of the flange ring 14 and the washer 15 make a very close running fit. The possibility of leakage between these contacting faces is prevented so long as the two are held in contact. Flanged ring 14 and shaft 11 form an annular channel which contains a resilient seal ring 20. The internal diameter of the seal ring 20 is slightly less than the diameter of the shaft 11, and the external diameter is slightly greater than the internal diameter of the flanged ring 14. When the seal ring 20 is contained in the channel, the seal ring is held under compression between the shaft and flanged ring 14. The seal ring 20 provides a leak-proof joint with the shaft 11 and flanged ring 14, and at the same time provides a friction drive connection between the shaft 11 and the flanged ring 14. A second flanged ring and seal ring combination is provided on the outward end of shaft 11 and operates in substantially the same manner as the previously described combination. A compression spring 22 bears against the washers 21 which abut the flanged rings 14. This spring forces the rings into contact with washers 15 and 24. The Durdin patent specification states that if the shaft 11 oscillates or reciprocates, the seal ring will be free to roll or rock upon the shaft or flange and thus the problem of seal ring wear is eliminated. The Durdin patent disclosure differs from the Christensen patent in that the Durdin seal ring 20 is on a rotating shaft and which may have only slight incidental reciprocation, whereas the Christensen O-ring is used on a reciprocating piston. Further, Christensen's patent claim 5 recites a cylinder and piston arrangement, whereas the Durdin patent disclosure relates to a seal for a rotating shaft. The Durdin patent does not anticipate claim 5 of the Christensen patent.
17. The Rasmussen patent relates to an oil well blowout preventer which includes a sealing means automatically operable to constantly seal the upper end of an oil well casing while offering no obstacle to the raising, lowering, or rotation of the drill pipe or casing. This patent, which was cited by the Patent Office examiner during the prosecution of the patent in suit, teaches two types of packing elements. The first type is a sealing ring which fits in a groove in the wall of the casing and surrounds the well tubing. The bottom of the groove is spaced from the well tubing a distance greater .than, the normal radial dimension of the sealing ring. The bottom of the grooves has an open passage leading to the bore of the well. In normal operation the sealing ring offers little resistance to the reciprocation of the well tubing. When fluid pressure increases in the well, the pressure is transmitted through a passage to a point beneath the sealing ring in the groove and forces the sealing ring into contact with the well pipe. This type of packing element differs from that disclosed in the Christensen patent in that it does not provide a constant seal and relies on fluid pressure to effect a seal. The Christensen packing provides a constant .seal and relies on the compression of an O-ring between the cylinder wall and piston to produce the seal. A second type •of packing element taught in the Rasmussen patent is a gland type packing in which the packing does not seal the pipe until .a gland member is forced against the packing to compress the packing. This second type seal is not used when the well pipe is reciprocating. The Rasmussen patent disclosures do not anticipate claim 5 of the Christensen patent.
18. The British Robertson patent relates to improvements in 'ball valve fittings for automatically controlling the supply of water to flushing cisterns to render the operation of such •valves more silent, certain, and effective, and their repair more simple. Referring to fig. 5 of the patent drawings, which are reproduced in part herein, float 27 rests upon the ^surface of liquid 28 in tank 29 and has an arm 30 pivoted near its upper end to move a slidable valve or plunger 20 in a guiding cylinder 25. The upper end of arm 30 moves valve 20 in the guiding cylinder 25 and into contact with -the valve seat 35 of waterway 26 to prevent further water from entering the tank 29. When the tank is emptied, float 27 falls and arm 30 pivots, causing valve 20 to open .the waterway. Valve 20 has a groove 21 provided with a .rubber ring 22 of circular cross-section. The depth of the groove containing ring 22 is approximately the same as the cross-section diameter of the ring 22, and the ring 22 is .not compressed into ellipsoidal cross-section as recited in -.the patent claim in suit. The ring 22 acts as a bearing member to ease the movement of the valve 20 through guiding cylinder 25. The Robertson foreign patent dis closure differs from that of the Christensen patent in that the Bobertson ring 22 does not operate to effect a seal in a differential pressure assembly, but is only a bearing number. The Bobertson patent disclosure does not anticipate claim 5 of the Christensen patent.
19. The defendant also urges that the patent claim in suit is anticipated by a disclosure entitled Piston Water Meter, contained in British Proceedings of the Institute of Mechanical Engineers, 1856, page 153. This early foreign publication disclosure shows a piston having a full rolling ring in a groove many times as wide as the cross-section diameter of the ring. This foreign publication disclosure is merely cumulative of the constructions mentioned in findings 11 and 12 above and requires no further discussion.
20. The defendant also alleges that combinations of the several patents listed in finding 10 above anticipate claim 5 of the Christensen patent. A person having ordinary skill in the packing art at the time of the Christensen invention, and having all of the listed prior art before him, would not have discovered it obvious that the Christensen patent combination would provide an effective seal in a reciprocating piston and cylinder device.
21. Summarizing findings 9 through 20, it is found that claim 5 of United States Letters Patent No. 2,180,195 issued to Niels A. Christensen is valid.
MISUSE
22. In its First Amended Answer defendant alleges misuse of the patent in suit as follows:
Upon information and belief defendant alleges that said Niels A. Christensen during the term of the patent in suit granted nonexclusive licenses to manufacturers of packings and to others to make and sell throughout the United States unpatented packings for use in the packing construction described in the patent in suit, namely, Patent No. 2,180,195, as a part of, repairs for, or replacement in devices in which the packing construction of the patent is a part, said licenses providing that said Niels A. Christensen licenses any purchaser of such unpatented packings from said licensees, first named, to use such unpatented packings so sold, in accordance with said patent; and alleges that said Niels A. Christensen thus attempted to use his patent to induce purchasers of the unpatented packings to purchase them from his licensees and thus to restrain competition in the unpatented packings and to extend the patent monopoly beyond its lawful boundaries, and thus said Niels A. Christensen misused the patent in suit so as to bar plaintiffs as his executors from asserting the patent against defendant.
23. Defendant in support of this allegation has introduced in evidence an agreement dated January 11, 1946, between Niels A. Christensen and Linear Incorporated, together with a copy of a supplemental agreement dated January 81, 1950. Similiar agreements were also entered into with Goshen Rubber Manufacturing Company, Plastic Rubber Products, Inc., of Dayton, Ohio, and Plastic Rubber Products, of Los Angeles, California, in addition to Linear Incorporated. Defendant calls attention in particular to certain paragraphs of the agreement and supplemental agreement as follows :
[Agreement dated January 11,1946]
$ $ ‡ $
Whereas, Licensee manufactures, fabricates and produces packings used in the construction described in said United States Letters Patent No. 2,180,795: and _
_ Whereas, the Licensee is desirous of obtaining a license to make and sell said packings for use in said packing construction described in said United States Letters Patent No. 2,180,795:

1. Licensor hereby grants to Licensee a non-exclusive license to make and sell throughout the United States packings for use in said packing construction described in said United States Letters Patent No. 2,180,795, as a part of, repair for or replacement in devices in which said packing construction is a part.
2. Licensee agrees to pay to the Licensor a royalty of one-fourth cent (%0) °n each packing licensed hereunder and sold by Licensee irrespective of the size of said packing.
3. Licensee agrees to keep an accurate record showing the number of packings made and sold and the names and addresses of the vendees, which records shall be open for inspection by the Licensor or his duly authorized agent during business hours of the Licensee.
[Supplemental Agreement dated January 31,1950]
¡s
1. Paragraph No. 1 of said Agreement of January 11, 1946, is hereby cancelled and the following is substituted therefor:
"Licensor hereby grants to Licensee a non-exclusive license to make and sell throughout the United States packings for use in said packing construction described in said United States Letters Patent No. 2,180,795, as a part of, repair for, or replacement in devices in which said packing construction is a part, and hereby licenses any purchaser from the licensee to use the packing so sold, in accordance with said patent."
2. Paragraph No. 2 of said Agreement of January 11, 1946, is hereby cancelled and the following is substituted therefor:
"There shall be paid to the Licensor for each packing construction used in accordance with said patent, a royalty of one-fourth cent (%0) irrespective of size of such construction. The Licensee shall act as the agent of the Licensor in collection of such royalty, and shall make payments to the Licensor in the manner hereinafter set forth."
All other provisions of said Agreement dated January 11, 1946, shall remain in full force and effect to the same extent as though this Supplemental Agreement had not been made.

24. Defendant offered no evidence in support of its misuse defense, other than the aforementioned agreements.
25. In 1947, Niels A. Christensen, through his attorneys, listed the patent here in suit with the United States Patent Office in the Eegister of Patents Available for Licensing, and submitted to the Patent Office, for public inspection, a license form under which the patent could be licensed. This license form provides in part as follows:
1. Licensor hereby grants to Licensee and Licensee hereby accepts a non-exclusive license to make, use, and sell the packing construction claimed in said United States Letters Patent No. 2,180,795.
2. Licensee agrees to pay the Licensor a royalty of one-fourth cent for each packing construction licensed hereunder and sold by- Licensee. For the pur pose of this license, a packing construction shall be defined as constituting a single packing ring and its associated groove. Moreover, for the purpose of this license, a sale shall be deemed to have been made when devices containing a packing construction are shipped by Licensee to some place other than its own warehouse.
26. There is no evidence that the plaintiff intended to secure a monopoly on the sale of unpatented O-rings, per se, nor is there any evidence that plaintiff has in fact acquired any monopoly in O-rings.
27. Summarizing findings 22-25 above, it is found that the evidence does not warrant a finding that Niels A. Christensen or plaintiffs attempted to use the patent here in suit to restrain competition in the sale of unpatented pack-ings or attempted to extend the patent monopoly beyond its lawful boundaries. There has been no misuse of the patent in suit.
CoNclttsioN op Law
Upon the foregoing findings of fact, which are made a part of the j udgment herein, the court concludes as a matter of law that claim 5 of United States Letters Patent No. 2,180,795 is valid, that the invention covered 'by said patent claim was used by defendant without authorization of the patent owner, and that plaintiffs are entitled to recover reasonable and entire compensation for such unauthorized use, and judgment is entered to that effect. The extent of liability will be determined in further 'proceedings before a trial commissioner, pursuant to Eule 17(c) (2).