Court Opinion

ID: 8595349
Source: CourtListenerOpinion
Date Created: 2022-11-23 16:02:28.981479+00
Date Added: 2024-06-11T16:54:53.017017
License: Public Domain

pee ctjeiaM ; These consolidated cases come before the court on defendant’s exceptions to the opinion and recommended decision, filed May 16, 1967 [pursuant to then Buie 57 (a) ], by then Commissioner Donald E. Lane (now Judge of the United States Court of Customs and Patent Appeals) and to the supplemental opinion and recommended decision, filed 'September 20,1974 [pursuant to Buie 134 (h) ], by Trial Judge Joseph V. Colaianni. The court has considered the cases on the briefs and oral argument of counsel. Since the court agrees with the opinions, findings of fact and recommended decisions filed May 16,1967, and September 20.1974,
*520as hereinafter set forth, it hereby affirms and adopts them as the basis for its judgment in these cases. Therefore, the court concludes as a matter of law that claims 7 and 8 of United States Letters Patent No. 2,945,666 are valid and have been infringed by the defendant’s unauthorized use of ball valves produced by the Electric Boat Division of General Dynamics Corp. and by Worcester Valve Co., Inc., and that plaintiff is entitled to recover reasonable and entire compensation therefor. Accordingly, judgment is entered for plaintiff with the amount of recovery to be determined pursuant to Buie 131(c) (2).
OPINIONS OF TRIAL JUDGES
Lane, Commissioner:
This is a patent suit under Title 28 U.S.C. § 1498 to recover reasonable and entire compensation for the unauthorized use or manufacture by or for the defendant of a patented invention. Plaintiff specifically alleges that ball valves manufactured by Electric Boat Division, General Dynamics Corp. and by Worcester Valve Co., Inc., and procured and used by the defendant embody an invention defined in varying scope in patent claims 7 and 8 of U.S. Letters Patent No. 2,945,666, entitled “Ball Valve.” Said patent, referred to hereinafter as the patent in suit, issued to plaintiff on July 19, 1960, on an application for patent filed February 14,1958, which was a continuation in part of a parent application filed June 11,1954. After the trial on liability was completed with briefs and requested findings being submitted, plaintiff’s ownership of the patent in suit was put in issue by E. W. Bliss Co. in the United States District Court for the District of Massachusetts. In view of the suit in Massachusetts, the parties have stipulated to stay action on the present suit, after commissioner’s report has been filed, until the ownership issue has been settled in the Massachusetts District Court. Plaintiff has agreed to dismiss the present suit if the District Court finds against plaintiff on the issue of ownership. The parties have also agreed to defer trial of any accounting issues until the issues of patent infringement and patent validity are decided.
It is concluded that claims 7 and 8 of the patent in suit are valid and that ball valves manufactured by both the Electric *521Boat Division, General Dynamics Corp., and by Worcester Valve Co. which were procured and used by the defendant infringe said patent claims.
The patent in suit describes and claims an improved ball valve. A ball valve is used to control the flow of liquids and gases in pipelines and includes a casing adapted to be connected to a pipeline and having a valve chamber with both an inlet and an outlet opening. A ball having a passage extending through it is mounted for rotation in the valve chamber. In one position of rotation, the passage in the ball is alined with the inlet and outlet openings to permit fluid flow through the ball valve and in another position of rotation, the passage is positioned at right angles to the inlet and outlet openings in the valve casing to prevent the flow of fluid.
Prior to the development of the plaintiff’s patented valve, ball valves were not generally accepted or used by industry. In early ball valves, the ball with a passage extending there-through was tightly journaled into the valve chamber. Temperature variations, pressure variations, and/or valve wear, either caused the valve to leak or made it extremely difficult to operate by rotating the ball between open and closed position. Attempts to solve this problem were made by journaling the ball against some material, preferably nonmetallic, in what were known as compression sealing rings placed about the outlet opening and about the inlet opening. The ball was truncated on each side where the passage ends and reduced ball pressure resulted when the ball was placed so that the passage lines up with the openings in the casing in the open valve position. When the ball was rotated to a closed position, the nontruncated portion of the ball pressed into the material of the sealing rings with sufficient force to provide a fluid tight seal. These compression sealing rings made no provision for expansion or contraction of the ball or casing and for valve wear. Compression sealing rings did compensate somewhat for the problems of leakability and ease of ball rotation but not adequately for use in modern industry.
The ball valve which is the subject matter of the patent in suit solved the problems of temperature variation, pressure variation, and valve wear. The patented ball valve employs a novel sealing ring utilizing a principle different from the *522compression sealing rings which, seal by the nontruncated portion of the ball pressing into the material of the sealing rings. The sealing ring of the patent in suit has a portion which flexes with respect to the remainder of the sealing ring and which is known as a lip. This lip projects inward with a graduated stiffness due to its increasing cross sectional shape in the radial direction. The lip is prestressed which causes it to flex into sealing contact or engagement with the ball even when the ball is being rotated. For a more detailed explanation of the patent in suit see finding 10.
After the patented valve was described in several trade journals, over 1,000 inquiries were received which later became purchase orders for the valve. This flow of inquiries and orders grew so fast that plaintiff could not keep up with production orders. Plaintiff grew from a corporation having 3 or 4 employees at the time of the announcement in 1954 to over 550 employees at the time of trial in January 1966. Over 3 million ball valves valued at over $50 million were sold since the announcement in 1954.
In the summer or fall of 1957, an engineer from the Portsmouth Navy Yard approached plaintiff about the possible use of the plaintiff’s valve on Navy submarines. Increased size and better hull construction enable the modern submarine to navigate at greater depths. Valves must operate under greatly increased pressure, be able to withstand hydraulic shock caused by depth charges, permit fluids to flow silently, work under problems of corrosion and erosion with sea water, and be remotely operable. No other valve in industry or in prior submarine service except the plaintiff’s valves solved all of these problems.
At the request of the Portsmouth Navy Yard, plaintiff’s engineers lectured on the theory and function of ball valves to the engineers of the Electric Boat Division, General Dynamics Corp. which was building nuclear submarines but had no ball valves or even contemplated using them. In April, 1958, Electric Boat informed plaintiff that they were going to make their own ball valves and no longer needed plaintiff.
Nylon and teflon were available well before plaintiff’s ball valve was developed, and defendant’s contention that the *523commercial success of the patented valve resulted from the availability of nylon and teflon is without merit.
Defendant has interposed the usual defenses of the invalidity and/or noninfringement of claims 7 and 8 of the patent in suit. In interposing these defenses, defendant’s major contention is that because of the prosecution history of claims 7 and 8 of the patent in suit, the clear language of these claims must be limited. More specifically, defendant argues that although claims 7 and 8 call for a sealing ring and the claim language does not limit whether that sealing ring is placed on the upstream side or on the downstream side of the valve chamber, the prosecution history forces the claims to be interpreted as being limited to a sealing ring on the upstream side of the valve chamber.
Patent claims 7 and 8, set forth in finding 11, define a ball valve comprising a casing, valve chamber having openings, a rotatable ball in the chamber and having a port, and a sealing ring mounted in the chamber around one of the openings, the sealing ring having a lip extending toward the axis of the ring and engaging the ball. Claims 7 'and 8 define the lip as free to bend in the axial direction and increasing in thickness outward in the radial direction of the ring, which projects inwardly toward the axis of the sealing ring and sealingly contacts or engages the ball, and which is free to move in the axial direction of the sealing ring. Claim 8 further defines the lip as having one side face disposed toward the ball and one side face away from the ball, which faces diverge from each other substantially uniformly outward in the radial direction of the ring.
The prosecution history of claims 7 and 8 of the patent in suit is discussed in detail in finding 13. Plaintiff urged that claims 7 and 8 distinguished over Saunders’ French patent 1,018,974 because the lip on the sealing ring disclosed in Saunders would not seal on the upstream side. It was the patentees’ position during the prosecution of the application for patent that if the lip didn’t increase in thickness outward in the radial direction as defined in claims 7 and 8 but was uniform in thickness as disclosed in Saunders, the lip would bend at an intermediate point to such an extent that the lip would curl away from the ball and cause a leak on the *524upstream side. The Patent Office examiner allowed claims on the basis of this argument. The clear language of patent claims 7 and 8 covers either a downstream or an upstream seal. The patentees were not required to argue the advantages of a sealing ring on the downstream side since the lip shown in Saunders would not seal on the downstream side of the valve. The clear language of patent claims 7 and 8 is not limited by the prosecution history to an upstream seal but also covers a downstream seal.
In O'Brien v. O'Brien, 202 F. 2d 254, 96 USPQ 290 (7th Cir. 1953), the patentee in the prosecution history of the patent there in suit argued that one of the advantages of his invention was that a conventional motor could be used. The allowed claims were not limited to a conventional motor but recited “a motor.” The accused construction there was identical to that of plaintiff’s device but used an unconventional motor. In holding that the prosecution history did not limit the claims to a conventional motor, the court stated:
It is hardly reasonable to think that the patent would have issued over the prior art merely on this particular feature without including it in the claims which, after all, measure the grant [202 F. 2d at 257, 96 USPQ 293].
In support of its contention that claims 7 and 8 are un-patentable in view of the prior art available at the time the invention was made, the defendant directs attention to several prior patents set forth in the findings. Each of these prior patents discloses a valve having a casing, a valve chamber, and a ball with a passage extending through it which rotates between an open position with the passage alined with the inlet and outlet openings of the valve casing and a closed position where the passage is out of alinement with the openings. Defendant relies particularly on Blevans patent 2,516,947, Australian patent 126,685, and British patent 692,085. Blevans shows a valve having a mechanism for axially moving the core out of engagement with a sealing ring before the core is rotated. The lips of the sealing ring disclosed in Blevans are not always in sealing engagement with the core when the core is rotated from an open position to a closed position or vice versa. Australian patent 126,685 discloses a ball and stem made of one piece which cannot *525move axially. The sealing rings of flexible material such as rubber may be chamfered where the ball bears against them. Since flexible sealing rings of the Australian patent are firmly against the ball and the ball cannot move axially under fluid pressure, there is no lip free to bend in the axial direction of the sealing ring as defined in claims 7 and 8 in suit. The sealing rings of the Australian patent are in sealing engagement with the ball when fluid pressure acts upon the backs of the sealing rings. Claims 7 and 8 define a sealing ring having a lip which is always in sealing contact with the ball. Defendant has placed particular eipphasis on Saunders British patent 692,085. Saunders French patent 1,018,947 (the equivalent of the British Saunders argued here) was considered by the Patent Office when allowing patent claims 7 and 8 here in suit and there is a presumption that these claims are patentable over the Saunders valves. Saunders discloses rubber sealing rings which utilize a compression seal wherein portions of the ball mash the sealing rings. In addition to the compression seal, Saunders discloses a lip on the rubber sealing ring which contacts the ball when fluid pressure forces it against the ball. Saunders’ lip does not increase in thickness outward in the radial direction of the sealing ring as required by claim 7 nor does the lip have side faces disposed toward and away from the ball which diverge from each other substantially uniformly outward in the radial direction of the ring as required by claim 8 in suit. Saunders lip is straight edged and of uniform thickness. Plaintiff successfully argued in the prosecution history that a straight-edged lip, like the Saunders lip, would bend at an intermediate point and curl away from the ball to cause a leak. Claims define a lip increasing in thickness outward in the radial direction of the ring patentably distinguished over the Saunders constructions. Defendant’s contention that this argument was erroneous is without merit. None of the several cited prior art patents either singly or collectively disclose a ball valve having a sealing ring with the structural and functional features of the ball valve defined in claims 7 and 8 in suit.
Defendant urges that under 35 U.S.C. § 103 it would have been obvious to one skilled in the art to provide the straight-*526sided sealing rings of Saunders with a tapered lip as shown in Antonelli patent 2,348,587. There is no suggestion in Anto-nelli that the rubber dual wiping lips there disclosed could be used in a ball valve of the Saunders construction. The Antonelli dual wiping lips are not free to bend axially in the direction of the sealing ring but are compressed downward and would not seal or stay on the valve ball if substituted in the Saunders construction. The Antonelli lips are tapered but to prevent the exterior faces of the lips from being extruded and pinched between the flanges of the sealing ring retaining shell and not to progressively increase the sealing force between the dual lips and the ball. Even if the tapered lip disclosed in Antonelli could be substituted in Saunders, the lip in Saunders is not always in engagement with the ball as required by the claims at issue. Claims 7 and 8 are valid over any attempted combination of Saunders with Antonelli.
In addition, defendant urges that claims 7 'and 8 are invalid as indefinite under 35 TJ.S.C. § 112 because the terms “lip,” “axis,” “axial,” and “radial” are nowhere defined in the specification. This contention is without merit. Claims 7 and 8 are clear and definite to one skilled in the ball valve art when read in light of the specification and drawings. These claims can be easily read on the illustrative drawings and are valid.
Now turning to the issue of infringement, plaintiff alleges that certain ball valves manufactured by Electric Boat Division, General Dynamics Corp. (hereinafter called the Electric Boat ball valve) and that certain ball valves manufactured by the Worcester Valve Co. (hereinafter called the Worcester ball valve), which were procured and used by the defendant, infringe claims 7 and 8 of the patent in suit.
An accused device may infringe the claims of a patent if the patent claim reads element for element on the device. Even where the patent claim does not read element for element, if the accused structure performs substantially the same way to obtain the same result, infringement may exist imder the doctrine of equivalents. Graver Tank & Mfg. Co. v. Linde Air Products Co., 339 U.S. 605, 85 USPQ 328 (1950). In Graver Tank, the Supreme Court indicated that an important factor in determining whether different struc*527tures are equivalent is whether “persons reasonably skilled in the art would have known of the interchangeability” of the structures.
Both the Worcester ball valve and the Electric Boat ball valve include a conventional casing, valve chamber, and a ball with a passage extending through it which rotates between an open position with the passage alined with the inlet and outlet openings of the valve casing and a closed position where the passage is out of alinement with the openings, which ball cooperates with a sealing ring mounted around one of the openings. Infringement rests on whether the Electric Boat sealing ring and/or the Worcester sealing ring are within the scope of claims 7 and 8 of the patent in suit.
The Electric Boat sealing ring has an outer body portion and an inner portion which is of reduced cross sectional area and which projects inwardly toward the axis of the ring and contacts the ball. This inner portion is shaped in the form of a projecting edge or lip which increases in thickness outward in the radial direction of the ring as required by patent claim 7. Although the portion of the Electric Boat sealing ring designated as the lip has surfaces of differing inclinations, the faces of the lip, one disposed toward the ball and the other away from the ball, diverge substantially uniformly outward in the radial direction as required by patent claim 8. The issue is whether the lip is free to bend in the axial direction of the sealing ring. Defendant argues that the Electric Boat sealing ring does not function substantially the same way to obtain the same result but instead torsion-ally twists by the ball pressing on the lip to rotate the entire sealing ring about a circular line representing the locus of points which are the centroids of the cross sections of the sealing ring. It is obvious, however, that the inner portion of the Electric Boat sealing ring is of reduced cross section due to its tapered cross sectional shape and that there will also be lip bending sealing in the Electric Boat ball valve. Tests conducted on the Electric Boat sealing ring demonstrated that there were both substantial torsional twisting and substantial lip bending. The torsional twisting is additive in nature and is not exclusive of the lip bending defined *528in patent claims 7 and 8. The Electric Boat ball valve responds to claims 7 and 8 of the patent in suit and performs substantially the same function to obtain substantially the same result. The accused Electric Boat ball valve infringes patent claims 7 and 8.
With regard to the accused Worcester ball valve sealing ring, the major issue is whether this sealing ring has the lip configuration defined by claims 7 and 8. The Worcester sealing ring has an inner axial surface which is a spherical portion having a radius greater than that of the ball. The inner radial portion of the sealing ring is reduced in cross sectional area and tapers outward in the radial direction due to the spherical axial inner surface, a flat cylindrical axial outer surface, and the parallel flat front and rear faces. When the sealing rings are mounted in the valve chamber about each of the inlet and outlet openings, the distance between the rings is less than the diameter of the ball so that the ball pre-loads the inner radial tapered portion of the sealing ring by contacting approximately 50 percent of the axial inner spherical portion. As the ball is moved by fluid pressure downstream, the ball bends a portion of the tapered portion and compresses a portion of the sealing ring so that the area of contact increases from 50 percent up to 100 percent of the inner spherical surface as the pressure increases. The Worcester ball valve sealing ring combines lip bending with a progressive compression sealing between the ball and the seat. This progressive compression sealing is additive in nature and not exclusive of the lip-bending concept defined in claims 7 and 8 of the patent in suit. The tapered portion of the Worcester ball valve sealing ring functions in substantially the same way to produce substantially the same result as the lip defined in claims 7 and 8. The Worcester ball valve infringes patent claims 7 and 8.
Both of the accused ball valves include sealing rings in which grooves are provided in their outer peripheral edges to permit fluid to escape through the sealing ring on the upstream side of the valve. Defendant argues that the accused ball valves do not infringe claims 7 and 8 of the patent in suit because the prosecution history limits the claims to a ball valve having lip sealing on the upstream side. The *529prosecution history does not so limit the clear intent of claims 7 and 8 to define either an upstream sealing ring or a downstream sealing ring.
Colaianni, Trial Judge:
On May 16,1967, Commissioner Donald E. Lane1 rendered an opinion,2 proposed findings of fact, and a recommended conclusion of law in which he concluded that claims 7 and 8 of plaintiff’s United States Letters Patent No. 2,945,666 (hereinafter referred to as the ’666 patent) were valid and infringed by defendant’s unauthorized use of ball valves manufactured by the Electric Boat Division of General Dynamics Corp. and Worcester Valve Co., Inc.3 However, prior to final action, plaintiff’s ownership of the patent in suit was put in issue by E. W. Bliss Co., an intervenor in an infringement action in the United States District Court for the District of Massachusetts between Jamesbury Corp. as plaintiff and Worcester Valve Co., Inc., as defendant. In view of the Massachusetts suit, the parties agreed to a stay of proceedings in the present suit, after the commissioner’s report had been filed, until ownership of the patent in suit had been settled in the Massachusetts court.
On June 29,1971, plaintiff reported to this court that following a full trial on the issue of ownership, the United States District Court for the District of Massachusetts entered judgment for Jamesbury Corp., 318 F. Supp. 1 (1970). Plaintiff further reported that the District Court’s judgment had been affirmed by the United States Court of Appeals for the First Circuit, 443 F. 2d 205 (1971). At the same time, plaintiff moved to remand the case to the trial division of this court for further proceedings and additional findings of fact concerning an issue raised by E. W. Bliss Co. and commented upon, without deciding, by the Massachusetts District Court, to wit, whether the named inventors of the patent in suit, Howard G. Freeman and Oscar It. *530Vaudreuil, were joined in a manner irremediably contrary to applicable law. Thus, at 318 F. Supp. 6, in fn. 6, the District Court in Massachusetts stated:
If relevant, the court would find that Vaudreuil was added to the application as a spurious joint inventor to shield Jamesbury against any claim by Rockwood that its president and principal shareholder had conceived the invention while a Rockwood employee.
On appeal, the First Circuit noted this finding and James-bury’s strenuous objection that it was erroneous. The decision of the First Circuit indicated that the finding was clearly dictum and not binding in other litigation, but because it felt that there was evidence to support it, the court concluded that the finding could not be said to be clearly erroneous.
In addition, plaintiff moved to remand this case back to this court’s trial division so that additional findings of fact could be made concerning a patent called to plaintiff’s attention by Worcester Valve Co., defendant in the Massachusetts action, during the settlement discussions between the parties. The patent, Melichar, et al., United States Patent No. 2,409,-220 (hereinafter referred to as the ’200 patent) was, according to plaintiff’s remand motion, alleged by Worcester Valve Co. to constitute a reference highly pertinent to the validity of the patent in suit. Although defendant opposed plaintiff’s motion to remand, this court, in an order dated October 1, 1971, remanded this suit to allow defendant to raise in supplemental pleadings the issues of misjoinder of inventors and the effect of Melichar, et al., on the validity of the claims in suit.4
*531In accordance with said order, an additional trial was conducted. The issues at trial were limited to whether:
(1) there was a misjoinder of inventors in the patent in suit because Fi’eeman was the sole inventor of all subject matter contained and claimed therein;
(2) Vaudreuil was added as a coinventor without error and with deceptive intent in order to deceive Bockwood, Freeman’s former employer, into believing that the invention claimed in the patent was developed when Freeman started working with Vaudreuil, after he left Bock-wood’s employ, and
(3) the prior art patents of Melichar, et ál., and Cross British Specification No. 373,660 render the claims in suit unpatentable.
As a result of a careful and complete evaluation of each of defendant’s contentions, and for reasons which will be explained in considerable detail hereinbelow, it is concluded that claims 7 and 8 of the ’666 patent 'are valid and infringed by defendant’s unauthorized use of ball valves manufactured by the Electric Boat Division of General Dynamics Corp. and the Worcester Valve Co., Inc.

Background

Howard G. Freeman obtained a bachelor of science degree in mechanical engineering from Worcester Poly technical Institute in June of 1940. Upon graduation, he was hired by the Bockwood Sprinkler Co. (hereinafter referred to as “Bock-wood”) of Worcester, Mass. He was later named director of research, and held that position until January of 1954.
On August 28, 1940, which was shortly after he began his employment at Bockwood, Freeman executed an employment agreement. The agreement provided in pertinent part that Freeman was—
* * * to give to Bockwood the full benefit and enjoyment of any and all inventions or improvements which he may make while in the employ of Bockwood * * * and all inventions which are made or worked out on the time and at the expense of Bockwood. * * *
Said Freeman further agrees that he will without additional consideration disclose promptly to Bockwood all of the above-described inventions or improvements * * *.
*532During the course of his employment at Rockwood, some 19 United States patents, as well as the foreign counterparts of these United States patents, naming Freeman as inventor or coinventor, were issued by the United States Patent Office. Freeman agreed to the assignment of all of his rights, title and interest in each of these patents to Rockwood.
As part of his duties as director of research, Freeman was primarily responsible for designing and improving all of Rockwood’s products. He also had full authority, without the prior approval of any other company official, to submit ideas which he believed to be novel to Rockwood’s patent attorneys.
In turn, for his contributions, Freeman was included in Rockwood’s “key man” program under which company executives received bonuses based upon Rockwood’s earnings. At the time of his departure in 1954, Freeman’s compensation, including bonuses, was about $25,000 annually.
While Rockwood’s product line varied somewhat over the years, by the latter part of 1953 its principal products were sprinkler systems, fire fighting equipment, rescue equipment for airports, and ball valves. In 1953, ball valves constituted about 8 to 10 percent of Rockwood’s total annual sales.
Rockwood manufactured single seat compression-type ball valves while Freeman was employed there. This type of ball valve utilized a seat on only one side of the ball. Since, in the operation of these valves, the ball was jammed by a spring or other device against an opposing seat and formed a compression seal, the valve seat was referred to as a “jam seat.” While commercially successful, this type of ball valve had the disadvantage of only being able to control the flow of fluid adequately in one direction. Also, the “jam seats” on some valves would swell and cause the valves to leak. The swelling of a “jam seat” would also make a valve difficult to operate.
Beginning about 1945, Rockwood customers occasionally requested a ball valve which would be capable of controlling the flow of fluid through it in either direction. However, such a valve was never manufactured by Rockwood while Freeman was its director of research.
*533In the fall of 1953, while still director of research, Freeman became somewhat dissatisfied with his employment at Rock-wood and discussed the possibility of going into the ball valve manufacturing business with a personal friend, Saul Reck. It was contemplated that Reck would manage the financial aspects of the new business and Freeman would contribute his engineering and design talents. After a number of meetings, Reck, who in the past had financed several new business ventures, obtained commitments of about $60,000 from several potential investors. The investors were apparently willing to take a chance with this new business venture on the understanding that there was a good market for ball valves.
On January 13,1954, Freeman met with William J. Carroll, Rockwood’s president, to express his dissatisfaction with his compensation and status at Rockwood. Freeman indicated that he would resign if something was not done. Freeman was told that he would be given an answer shortly. Failing to hear from Mr. Carroll by January 20, 1954, Freeman sent him a letter of resignation suggesting that his effective resignation date be J anuary 30, 1954. Freeman’s letter also indicated a willingness to serve an additional reasonable period or to have his resignation take effect sooner at Rockwood’s option. On J anuary 25,1954, Mr. Carroll met with Freeman, and they agreed that Freeman would leave that afternoon. Freeman’s employment and duties at Rockwood ended on that day.
Upon leaving Rockwood on January 25, 1954, Freeman called Mr. Reck and told him to do what was necessary to obtain the financing for the new company which they had earlier discussed. Jamesbury Corporation’s Articles of Incorporation were drawn up on January 29, 1954. The contributions by the initial investors were in the form of checks made out to Jamesbury Corp. and postdated February 2, 1954.
On February 1,1954, Freeman commenced a series of drawings and sketches of valve components. Some were undated, but none were begun before February 1, 1954. It took Freeman several days to complete the drawings and he did not complete any of them in a single day. While drawing and *534sketching during the first and second week of February, Freeman also began drafting a written description of three ideas he was working on. One of these ideas was for a new valve seat. The written statement describing Freeman’s new valve seat was completed before February 23, at which time the written description along with five illustrative sketches were taken to his patent attorney in Boston. The written description read in part:
The new valve seat has both a flexible sealing surface and a non-flexible surface to absorb compression load. By utilizing the design as shown, the lip seal is pre-compressed before the ball surface strikes the non-flexible surface. The intent of the design is to maintain a definite space between the seat and the ball to allow for swelling.
On the basis of this meeting, the patent attorney prepared a draft of a patent application containing four claims and a drawing containing four figures. The drawings specifically showed a seal configuration which included a V-notch, substantially as shown in Fig. >5 of finding of fact 36, to provide for greater flexibility. The claims of the draft application covered this V-notch design. The oath accompanying the draft named Freeman as the sole inventor of the claimed subject matter.
On April 27, 1954, this draft was forwarded to Freeman to review but the trial transcript fails to indicate if Freeman ever signed it or filed it in the United States Patent Office. Accordingly, the draft claims cannot be taken as establishing the metes and bounds of the V-notch seat as envisioned by Mr. Freeman. Indeed, the most that can be said of them is that they set forth the patent attorney’s understanding of what Mr. Freeman had invented.
In the latter part of March 1954, Freeman set up a lathe in space he had rented in Worcester, Mass., and started to make parts for his new valve. Shortly thereafter, he also set up apparatus to test the prototype valves he had made. Freeman’s initial efforts at producing a workable valve were unsuccessful and he continued to experiment with various modifications of his original V-notch design. He was particularly concerned about the valve seats tearing after only a few *535operations of a valve, but lie was unable to successfully find a solution to this design defect.
'Oscar Vaudreuil, since deceased, owned a machine shop in Worcester, Mass., which supplied Jamesbury 'Corp. with parts and services during 1954. Since Jamesbury Corp. had little cash to pay for these goods and services, Vaudreuil accepted stock in the corporation in lieu of money. Vaudreuil observed some of the tests being performed by Freeman. In order to overcome the seat tearing problem which Freeman’s design was experiencing, Vaudreuil suggested that a small part of the metal casing behind the flexible valve seat be chamfered or cut away. This part of the metal casing is represented by 44 in Fig. 9 of the ’666 patent {see finding 38). Adoption of the suggestion resulted in a valve seat that was free of the tearing defect that had plagued Freeman’s earlier design.
An analysis of Vaudreuil’s suggestion led Freeman to conclude that the chamfer provided lip flexibility, and that this necessary lip flexibility could also be obtained by cutting away one of the two lips of his V-notch valve seat instead of the more expensive and difficult chamfering of the metal casing. This modification of the valve seat was further refined into the design shown in Fig. 5 of the patent in suit (see finding 10).
In may 1954, Freeman returned to his patent attorney in Boston and described the changes that he and Vaudreuil had made to the valve. Freeman asked the patent attorney whether Vaudreuil was to be considered a coinventor and was told that he was.5
Plaintiff’s attorney revised the previously prepared draft application. This revised draft was later filed as Patent Application Serial No. 436,188 (hereinafter referred to as the ’188 application) by including therein the design change suggested by Vaudreuil as well as Freeman’s modification thereof. More specifically, Fig. 8 of the application incorpo*536rates the chamfer which Vaudreuil had suggested while Fig. 7 shows an equivalent modification that resulted by Freeman’s removal of one of the two lips of the original V-notch valve seat without chamfering the abutting casing.

Misjoinder

"While it is true that the inclusion of more or less than the true inventors in a patent renders it void, Iowa State University Research Foundation, Inc. v. Sperry Rand Corp., 444 F. 2d 406, 408, 170 USPQ 374 (4th Cir. 1971), there is a presumption that the inventors named in an issued patent are correct. Acme Highway Products Corp. v. D. S. Brown Co., 431 F. 2d 1074, 167 USPQ 129 (1970 6th Cir.), cert. denied, 401 U.S. 956 (1971); Mueller Brass Co. v. Reading Industries, 352 F. Supp. 1357, 176 USPQ 361 (E.D. Pa. 1972), aff’d, 180 USPQ 547 (3d Cir. 1973). ’Thus, it is well established in this court that since misjoinder is a technical defense, it must be proven by “clear and convincing” evidence. Garrett Corp. v. United States, 190 Ct. Cl. 858, 422 F. 2d 874, 164 USPQ 521, cert denied, 400 U.S. 951, 167 USPQ 705 (1970). This is the law in other courts as well. Acme Highway Products Corp. v. D. S. Brown Co., supra; Stein v. Biocoustics, Inc., 177 USPQ 680 (D. D.C. 1973); Congoleum Industries, Inc. v. Armstrong Cork Co., 339 F. Supp. 1036, 173 USPQ 147 (E.D. Pa. 1972).
In the present case the threshold issue to be decided with respect to misjoinder is whether defendant has demonstrated, by clear and convincing evidence, that Yaudreuil did not make a significant enough contribution to Freeman’s original V-notch to make Yaudreuil a coinventor of the subject matter of the claims in suit. As will hereinafter be explained, the evidence of record dictates that defendant has not so demonstrated.
The requirements of joint inventorship were stated in Monsanto Co. v. Kamp, 269 F. Supp. 818, 824 (D. D.C. 1967) :
A joint invention is the product of collaboration of the inventive endeavors of two or more persons working toward the same end and producing an invention by their aggregate efforts. To constitute a joint invention, it is necessary that each of the inventors work on the same *537subject matter and make some contribution to the inventive thought and to the final result. Each needs to perform but a part of the task if an invention emerges from all of the steps taken together. It is not necessary that the entire inventive concept should occur to each of the joint inventors, or that the two should physically work on the project together. One may take a step at one time, the other an approach at different times. One may do more of the experimental work while the other makes suggestions from time to time. 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, though partial, to the final solution of the problem.
The court went on, quoting from DeLaski & Thropp Circular Woven Tire Co. v. Wm. R. Thropp & Sons Co., 218 F. 458, 464 (D. N.J. 1914), aff'd, 226 F. 941 (3d Cir. 1915), to explain:
In order to constitute two persons joint inventors, it is not necesary 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.
The difficulty experienced in attempting to define a standard to be used to determine who is a joint inventor and the type of contribution that is necessary to qualify as a co-inventor is adequately illustrated in Mueller Brass Co. v. Reading Industries, supra, 352 F. Supp. at 1372, 176 USPQ, at 372:
The exact parameters of what constitutes joint inventor-ship are quite difficult to define. It is one of the muddiest concepts in the muddy metaphysics of the patent law. On the one hand, it is reasonably clear that a person who has merely followed instructions of another in performing experiments is not a co-inventor of the object to *538which those experiments are directed. To claim inven-torship is to claim at least some role in the final conception of that which is sought to be patented. Perhaps one need not be able to point to a specific component ■as one’s sole idea, but one must be able to say that without his contribution to the final conception, it would have been less — less efficient, less simple, less economical, less something of benefit.
Moreover, it is necessary, as the court in Mueller Brass Co. v. Reading Industries, supra, 352 F. Supp. at 1373, 176 USPQ at 372, recognized, to also consider the doctrine of “mere suggestions” which—
* * * denies co-inventorship status to a person who suggests some way to improve an invention casually but takes no further role in fitting the rough suggestion into the scheme of the invention workably. See Forgie v. Oilwell Supply Co., 58 F. 871 (3rd Cir. 1893).
The facts in the present case require the conclusion that Vaudreuil did make a contribution of very substantial importance to Freeman. In fact, before Vaudreuil made his contribution Freeman’s valve proved to be marginally operable at best with the seats tearing after the ball of a valve had been turned only a few times. However, as a result of Vaud-reuil’s contribution, tearing of the valve seat was eliminated and plaintiff eventually produced a valve that gained widespread use and substantial commercial success. The facts demonstrate that Vaudreuil’s contribution was of crucial importance to Freeman and that Vaudreuil must be considered a coinventor of the valves which incorporated his concept.
Since it is concluded that Vaudreuil did make a substantial contribution to the valve seat embodiments which followed Freeman’s unworkable V-notch design, the next question requiring attention is whether the claims in suit cover only the joint invention. Defendant contends that the claims in suit not only cover the joint invention, but they cover as well the original Freeman invention. If the former is true, then there is no misjoinder. On the other hand, if the latter is found to be true, there is misjoinder. In any event, in order to properly resolve this issue, it becomes necessary to establish the scope of claims 7 and 8. In Motion Picture Patents Co. v. Universal Film Mfg. Co., 243 U.S. 502, 510 (1917), the Su*539preme Court stated that: “The scope of every patent is limited to the invention described in the claims contained in it, read in the light of the specification.” More recently, the Supreme Court reiterated that position in United States v. Adams, 383 U.S. 39, 49, 148 USPQ 479, 482 (1966), when it stated: “* * * it is fundamental that claims are to be construed in the light of the specifications and both are to be read with a view to ascertaining the invention.” See also Tate Engineering, Inc. v. United States, 201 Ct. Cl. 711, 719, 477 F. 2d 1336, 1340 (1973).
The Supreme Court has also stated that “* * * an invention is to be construed not only in light of the claims, but also with reference to the file wrapper or prosecution history in the Patent Office.” Graham v. John Deere Co., 383 U.S. 1, 33, 148 USPQ 459, 473 (1966). This direction has been followed by a number of courts, including: Ellipse Corp. v. Ford Motor Co., 452 F. 2d 163, 171 USPQ 513 (7th Cir. 1971), cert denied, 406 U.S. 948 (1972); Waldon, Inc. v. Alexander Mfg. Co., 423 F. 2d 91, 165 USPQ 46 (5th Cir. 1970). Indeed, this court’s own pronouncement in Autogiro Co. of America v. United States, 181 Ct. Cl. 55, 384 F. 2d 391, 155 USPQ 697 (1967), stresses that the claims of a patent are necessarily construed in connection with the other parts of the patent instrument, as well as the circumstances surrounding the prosecution of the patent application through the Patent Office.
An analysis of the 10 claims contained in the originally filed ’188 application indicates that claims 1 through 8 were sufficiently generic to read on the original Freeman valve design, as well as upon the Freeman-Yaudreuil joint invention. Claims 9 and 10 only covered embodiments which were jointly invented by Freeman and Yaudreuil, and did not read on the Freeman Y-notch. The ’188 application was filed in the joint names of Freeman and Vaudreuil on June 11, 1954.
As a result of a first amendment to the ’188 application, Freeman and Yaudreuil canceled claims 6, 7, and 8 of the original 10 claims. By a second amendment, claims 1-5, 9 and 10 were canceled and new claims 11-13 added. As explained in the remarks accompanying the amendment, *540“Claim 11 corresponds in substance to Claim 10 * * Claim 10, as hereinbefore stated, originally read only on the joint Freeman-Vaudreuil invention. Similarly, since new claims 12 and 13 were dependent upon new claim 11, there can be no doubt that the joint inventors ultimately limited all of the claims in that application to the joint invention.
On February 14,1958-, the joint inventors filed a continuation-in-part application, Serial No. 715,372 (hereinafter referred to as the ’372 application) with the Patent Office. The drawings of this application illustrated only the joint Freeman-Vaudreuil invention, and did not illustrate the original Freeman V-notch. Specifically, Figs. 5 and 6 of the ’188 application, which illustrated the Freeman V-notch design, were not included in the ’372 application. In addition, Figs. 2 and 4 of the ’188 application were modified by eliminating the Freeman V-notch seat and substituting therefor the joint Freeman-Vaudreuil seat. Furthermore, new Figs. 5-7, depicting only the joint invention, were added.
The specification of the ’188 application was extensively revised and its entire emphasis changed. The new specification dealt almost exclusively with the joint invention while relegating the V-notch to a four sentence discussion. Furthermore, as a result of the use of the term “free standing lip” in each of the 10 claims filed with the application, all claims read only on the joint invention and not on the Freeman V-notch.
In response to a Patent Office rejection of the ’372 application over the parent ’188 application, the ’188 application was abandoned.
By subsequent amendment, applicants presented new claim 14 to the Patent 'Office. This claim, which eventually matured into claim 7 of the patent in suit, did not contain the term “free standing lip” and hence might be construed, if viewed in the abstract, as reading on the Freeman V-notch design. However, it is clear from the prosecution history that there was no intent on the part of Freeman and Vaudreuil to broaden the coverage of claims 7 and 8 by the elimination of the term “free standing lip.” Certainly, the acts of the applicants in prosecuting both the ’188 and the ’372 application in *541the Patent Office dictate against any intent on the part of the joint inventors to cover the V-notch design by claims 7 and 8.
Specifically, since the applicants had narrowed the claims in their parent ’188 application, and, as well, restricted all of the original 10 claims in the ’872 application, in view of prior art cited by the Patent Office to exclude the Freeman V-notch design, it would be improper to permit them, by way of the later submitted claim 14 in the ’372 continuation-in-part application, to recapture subject matter that they had willingly relinquished. To do so would ignore the well-established doctrine of “file wrapper estoppel” which does not allow recapture of relinquished subject matter under circumstances present in this case Exhibit Supply Co. v. Ace Patents Corp., 315 U.S. 126, 52 USPQ, 275 (1942); Hughes Tool Co. v. Varel Manufacturing Co., 336 F. 2d 61, 142 USPQ 407 (5th Cir. 1964).
Thus, it must be concluded that Vaudreuil is properly considered to be a coinventor with Freeman of the invention disclosed by claims 7 and 8 of the patent in suit, and that these claims do not cover the Freeman V-notch valve seat. Thus, there is no misjoinder of inventors present in this case.

Validity

In addition to its defense of misjoinder, defendant also contends that the ’666 patent is invalid. In support of its contention of invalidity, defendant, at the latest trial, relied on the Melichar, et al., and Cross patents. Title 35 U.S.C. § 282 provides that a patent is presumed to be valid and the burden of establishing invalidity rests upon the party asserting it. However, numerous courts have concluded that the failure of the Patent Office to consider important prior art references during its evaluation of the pending application is enough to overcome the statutory presumption of validity of an issued patent. See T. P. Laboratories v. Huge, 371 F. 2d 231, 151 USPQ 605 (7th Cir. 1966).
Defendant contends that claims 7 and 8 of the ’666 patent are invalid by reason of their failure to meet the require*542ments of patentability set forth in 35 U.S.C. § 103.6 In Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), the Supreme Court indicated that an analysis of the following factors is required in resolving whether or not a patent meets the requirements of patentability set forth in 35 U.S.C. §103-
(1) the scope and content of the prior art;
(2) the difference between the prior art and the claims in issue; and
(3) the level of ordinary skill in the pertinent art.
Secondary considerations, such as commercial success, satisfying a long-felt need, and the failure of others, are also relevant considerations in evaluating patentability under 35 U.S.C. § 103.
The 'above factual determinations must be made without resorting to the teaching of the patent at bar or the deceptive and oftentimes unwitting use of hindsight. See Garrett Corp. v. United States, 190 Ct. Cl. 858, 422 F. 2d 874, 164 USPQ 521 (1970), cert. denied, 400 U.S. 951, 167 USPQ 705 (1970).
For reasons which follow, it is concluded that neither the Melichar, et al., nor Cross patents, considered individually or in combination, disclose a ball valve having a sealing ring with the structure and functional features required to perform the intended purposes of the ball valve defined by claims 7 and 8 of the ’666 patent.
As explained in considerable detail in the findings, neither of the prior art patents deal with valves that control the flow of fluid in both directions through a ball. Neither Melichar, et dl., nor the Cross patents were concerned with a valve that was capable of controlling fluid passage through an apertured ball by a quarter turn of said ball. Accordingly, no attention was given, and no structure provided, to insure against the flexible lip of either’ Cross or Melichar, et al., being lodged *543into the fluid port of an apertured ball valve such, as used by the patented structure in suit.
The lodging of the lip into the fluid port would not only prevent the valve from being able to be completely turned into its on or off positions, but could result in complete in-operativeness of the valve if the lip were cut off in the movement of the ball valve between its open and closed conditions.
Moreover, neither of the prior art references teach the use of a lip seal or seals to totally support a ¡ ball valve in the manner disclosed by the Freeman-Yaudreuil patent. In addition, neither Cross nor Melichar, et at., disclose a lip which has a tapered cross-sectional shape in its radial direction to give the lip graduated stiffness, and, at the same time, provide a support surface for a ball valve over and above that initially provided by the lip that is subjected to additional fluid pressure when the ball valve is in its closed position.
Finally, neither Cross nor Melichar, et at., were concerned with and thus failed to provide the necessary structure, as the ’666 patent did, to solve the problems of temperature variation, pressure variation and valve wear, or to compensate for swelling of the valve seats.
Defendant also contends, in the event the court finds that there has been no misjoinder, that the subject matter of claims 7 and 8 of the patent in suit is obvious over the Freeman Y-notch design. Although plaintiff questions whether the Freeman Y-notch can be used as prior art against the joint invention covered by claims 7 and 8, the following cases support defendant’s position: In re Bass, 474 F. 2d 1276, 177 USPQ 178 (CCPA 1973); Sutter Products Co. v. Pettibone Mulliken Corp., 428 F. 2d 639, 166 USPQ 100 (7th Cir. 1970) ; Grinnell Corp. v. Virginia Electric & Power Co., 277 F. Supp. 507, 156 USPQ 443 (E.D. Va. 1967).
However, after a careful review of the facts hereinbefore stated, and from a review of the entire trial record, it must be concluded that defendant has failed to show that it would be obvious to one of ordinary skill in the art to modify the Freeman V-notch either by cutting a chamfer in the casing or by removal of the lip adjacent to the casing. In fact, the *544surprisingly superior results obtained when Vaudreuil’s contribution was effected speak to the nonobviousness of it. United States v. Adams, supra. Thus, upon incorporation of the Vaudreuil contribution into the valve, an inoperable device was changed into a commercially successful product. The unexpected superiority obtained by modifying the Freeman V-notch as plaintiffs did belies defendant’s contention and it, therefore, must be concluded that claims 7 and 8 of the patent in suit are unobvious over the original Freeman V-notch design.
In conclusion, it is specifically found that claims 7 and 8 define a patentable invention which was jointly invented by Messrs. Freeman and Vaudreuil, and that the invention defined'by said claims would not have been obvious to a person of ordinary skill in the art at the time that the joint invention was made.
FINDINGS OF FACT*
1. This is a patent suit under the provisions of Title 28 TJ.S.C. § 1498, filed July 10, 1963, to recover reasonable and entire compensation for the unauthorized use and manufacture by or for the United States of the plaintiff’s patented invention described and claimed in United States Letters Patent No. 2,945,666, entitled “Ball Valve.” A first amended and supplemental petition was filed June 2,1965. Specifically, the plaintiff charges that the defendant has used ball valves manufactured by Electric Boat Division, General Dynamics Corp., and by Worcester Valve Co., Inc., and that such use infringes claims 7 and 8 of said patent. The application for patent was filed February 14, 1958, and was stated to be a continuation-in-part of copending application filed June 11, 1954. The patent in suit was issued on July 19, 1960, to the plaintiff.
2. Plaintiff, Jamesbury Corp., is organized and exists under the laws of the State of Massachusetts, having its principal place of business in Worcester, Massachusetts. Howard G. Freeman, president of Jamesbury, and Oscar R. Vaudreuil are designated coinventors in patent 2,945,666.
*5453. The subject matter of the patent in suit relates to a valve apparatus for controlling the flow of fluids in a pipeline. The valve described in said patent is of the ball valve type. A ball valve structure comprises a casing adapted to be connected to a pipeline and having a valve chamber as well as inlet and outlet openings communicating with that chamber. A ball is mounted in said chamber, and is provided with a passage extending therethrough. In one position of rotation the passage in the ball is alined with openings in the valve casing so as to permit fluid flow through the apparatus. In another position of rotation the passage in the ball is positioned at right angles to the openings in the valve casing so as to prevent flow of fluid through the apparatus. Sealing rings are provided with the casing on either side of the ball closure in order to make the apparatus leakproof when the ball is positioned to prevent fluid flow. Apparatus of this general kind has been known in the patent art for at least 50 years.
4. Prior to plaintiff’s patented valve, ball valves were not generally accepted or widely used by industry. Originally, a ball with a passage extending therethrough was tightly jour-naled into the valve casing. Temperature variations, pressure variations, and/or valve wear, caused the valve to leak or made it extremely difficult to operate the valve by rotating the ball between open and closed positions. Attempts to solve this problem were made in the prior ball valve art by jour-naling the ball against some sealing material, preferably nonmetallic, in what were known as compression seats. Generally, the ball is truncated on each side where the passage extends through. This resulted in a reduced ball pressure against the seat when the ball is placed so that the passage lines up with the openings in the casing in the open condition. When the valve is closed, the nontruncated portion of the ball presses into the material of the seat with sufficient force to provide a fluid tight seal. A compression seat or seal is one which is designed so that the ball can, under pressure, press into the seat material sufficient to provide a fluid tight seal, the area of contact being determined primarily by the compressibility of the seat material. Such compression seats make no provision for expansion and contraction of the ball or casing and *546for valve wear. These attempts did compensate somewhat for the problems of leakability and ease of ball rotation but not adequately for use in high-pressure installations.
5. The Jamesbury ball valve construction which is the subject matter of the patent in suit solved the problems of temperature variation, pressure variation, and valve wear. The patented ball valve employs a sealing ring utilizing a principle different from the compression seat or sealing ring in which the ball presses into the material of the sealing ring. The Jamesbury sealing ring has a portion known as a lip which flexes or bends with respect to the remainder of the sealing ring. The lip projects inward and has a graduated stiffness due to tapered cross sectional shape in the radial direction. The lip is prestressed which causes it to flex into sealing contact or engagement with the ball at all times, even when the ball is being rotated.
6. After the Jamesbury valve was first described in several trade journals, over 1,000 inquiries were received and many later became orders for the purchase of the patented valve. This flow of inquiries and orders grew so fast that James-bury could not keep up with production orders. Jamesbury grew from a corporation having 3 or 4 employees at the time of the announcement in the trade journals in 1954 to over 550 employees at the time of trial on the merits in January 1966. Over 3 million Jamesbury ball valves valued at over $50 million have been sold since the trade journal announcement in 1954. Problems were solved in nonmilitary applications, in the synthetic rubber field, and in the handling of dangerous gases or chlorine.
7. The increased size and better construction of the hull of the modern submarine, including the nuclear submarine, enables the submarine to navigate now at much greater depths than heretofore. The operation of submarines at greater depths caused problems. Valves have to operate under great pressures, must be able to withstand the increased hydraulic shock caused by depth charges, and must permit fluids to flow silently. Prior valves used on submarines were generally of the Globe type which operate like a faucet and often make considerable noise. There were problems of corrosion and erosion with sea water in submarines and with the fact that the *547valves had to be remotely operated. Other Navy requirements could not be revealed due to security restrictions which hampered valve suppliers by not revealing the entire fluid system of the submarine for which the valves were to be supplied. Discussions could deal only with the valve constuction itself.
8. In the summer or early fall of 1957, an engineer from defendant’s Portsmouth Navy Yard contacted Jamesbury Corp. about the possible use of the Jamesbury ball valve on Navy submarines. At the request of the Portsmouth Navy Yard, Jamesbury turned its ball valve design and test results over to the Electric Boat Division of the General Dynamics Corporation which was then building nuclear submarines. At that time Electric Boat had no ball valves or even contemplated using ball valves. Jamesbury Corp. engineers lectured to Electric Boat engineers on the theory and function of ball valves. Jamesbury sold some ball valves to Electric Boat. In April 1958, Electric Boat informed Jamesbury Corp. that they intended to make their own ball valves and no longer needed Jamesbury.
9. No valve in previous submarine service met the strategic and operating valve needs of the modem submarine except the Jamesbury ball valve. Jamesbury ball valves were used successfully on at least three submarines. The valves met all of the Navy requirements. Some valves failed in actual use and were redesigned to overcome the problem of swelling due to expansion in sea water by cutting away the outer diameter of the Jamesbury seal. The redesigned ball valve was successful. Defendant’s contention that the Jamesbury valve was redesigned to incorporate torsional twisting is without merit.
10. The Freeman, et al., patent in suit states that one of its objects is to provide a valve seat construction which provides maximum security against leakage, which reduces wear and insures smooth opening and closing of the valve, and also provides a construction which is adapted for the manufacture of valve seats from hard plastics or metals or flexible rubber-like materials. Figures 2, 5, 6, and 7 of the patent drawings are reproduced herein. The patent discloses a ball valve comprising a casing including fittings 20 and 21 and a bonnet 23. The interior of the casing is provided with a valve chamber *548containing sealing rings 25 and 26. A ball 27 is positioned between the sealing rings and is provided with a passage 28 which can be turned to aline with the openings in the fittings 20 and 21 by operation of a handle 33. The operative engagement between the stem 32 and the ball 27 permits slight axial movement of the ball which is thus able to move against the sealing ring 25 or 26 in response to fluid pressure *549when the valve is closed by turning the handle 33 from the open position illustrated in Fig. 2 to the closed position shown in Fig. 7. The valve seats 25 and 26 are provided with an inwardly extending freestanding tapered portion designated as lip 25c in both Figs. 5 and 6. It is this lip 25c which contacts the surface of the ball 27 to provide a seal between the ball and the fittings. The lip 25c has a rounded inner surface 25d and an oblique surface 25e. Leading to the lip is another oblique surface 25f on which the ball becomes seated when the lip 25c is deflected under load. The patent specification states that there is a limited region of engagement between the ball and the seat and that the tapered portion or lip 25c, because of its shape, has a graduated stiffness against bending. The patent discloses that when the valve is assembled the dimensions of the seats in the ball are chosen so that the tapered portions or lips 25c are deflected by the ball, as illustrated in Fig. 6. This is referred to as “pre-loading” of the valve seats. The specific example of the invention illustrated in Fig. 6 of the drawings shows the oblique surface of the valve seat on the side toward the ball contoured so that there is no contact between this face and the ball in the preloaded condition, and so that upon deflection of the lip portion as a result of increasing fluid pressure being applied by the ball, the ball will contact and be partly supported by this face as illustrated at the left side of Fig. 7. The shape of the sealing rings is such that deflection of the lip 25c beyond a certain point permits additional contact between the ball 27 and the sealing ring 25 for such additional sealing. A ball valve utilizing seats of this kind is self-compensating with respect to wear and temperature changes.

*548

*54911. Patent claims 7 and 8 are involved in this suit. These claims are reproduced below (indentation added) :

Patent Claim 7

A ball valve comprising:
a casing adapted to be connected to a pipe line and having a valve chamber and inlet and outlet openings;
a ball mounted in said chamber and having a port; *550and a sealing ring mounted in said chamber around one of said openings,
said ring having a lip projecting inward toward the axis of the ring and engaging the ball, said lip being free to bend in the axial direction of the ring and increasing in thickness outward in the radial direction of the ring, and
said ball being rotatable between an open position in which said port is in register with the opening surrounded by said ring and a closed position.

Patent Claim, 8

A ball valve as described in claim 7,
said lip having side faces disposed one toward the ball and one away from the ball,
and said faces diverging from each other substantially uniformly outward in the radial direction of the ring.
Said claims read on and are supported by the drawings and specification of the patent in suit.
12. Defendant contends that patent claims 7 and 8 are invalid on the ground that they are indefinite and fail to distinctly claim subject matter as required by Title 35 U.S.C. § 112. More particularly, defendant contends that the terms lip, axis, axial, radial, and substantially uniformly, used in the claims are not defined or explained in the patent specification. The lip 25c is fully described and illustrated in the Freeman, et a!., patent in suit. The sealing ring lip 25c is described as free standing, as having oblique surface 25e and oblique surface 25f, as being deflected under load, and as having a graduated stiffness because of its shape. The specification states that the inner portion of the lip will tend to bend first. The axis of a ring is definite as is the radial direction of a ring. The patent clearly illustrates the oblique surfaces 25e and 25f in Fig. 5 as diverging substantially uniformly. It is found that the patent and patent claim terminology is definite, distinct, and adequate to enable any person skilled in the valve art to make and use the invention claimed. Defendant’s contention as to indefiniteness is without merit.
13. In obtaining allowance of patent claims, applicants contended in the Patent Office that claims having the limitation of a sealing ring with a lip which increases in thickness *551outward in a radial direction were patentable oyer prior art showing a straight nontapered lip. Applicants urged that fluid pressure on a straight lip would cause the straight lip to bend at an intermediate point and curl away from the valve ball and not provide an upstream seal. Defendant’s contention that such argument in the Patent Office limits claims 7 and 8 here in suit to an upstream seal is unsound. The clear language of these two patent claims applies to a sealing ring construction irrespective of whether it is a downstream or an upstream seal. The specification of the patent in suit clearly states that the valve disclosed is symmetrical in design and is intended for use in either direction with either ring 25 or ring 26 on the downstream side.
14. Defendant urges that patent claims 7 and 8 are invalid as not novel under 35 U.S.O. 102 and/or as obvious to'one skilled in the art under 35 U.S.C. 103 over the disclosures of prior U.S. patent 2,516,947, issued to Blevans in 1950; Australian patent 126,685, of 1946; U.S. patent 2,297,161, issued to Newton in 1942; and U.S. patent 2,762,601, issued to Clade in 1956.
15. Defendant argues that claims 7 and 8 of the patent in suit are invalid as lacking novelty over the Saunders British patent 692,085. This British patent was not cited by the examiner in the Patent Office, but corresponds essentially to Saunders French patent 1,018,974 which was cited and considered by the Patent Office. The Saunders ball valve construction includes a casing connected to a pipeline, a valve chamber provided with inlet and outlet openings, and a ball mounted in the chamber. In Saunders, a pair of sealing rings are mounted in the chamber around said inlet and outlet openings, and each of the sealing rings has a lip projecting inward toward the axis of the sealing ring. Claims 7 and 8 of the patent in suit call for the lip to engage the ball. When read in light of the specification and drawings of the patent in suit, the term “engaging the ball” recited in claims 7 and 8 means that the lip contacts the ball with sufficient force to provide a fluid tight seal. The lip of the Saunders sealing ring does not always contact or engage the ball, nor does the Saunders sealing ring lip function in substantially the same way as the lip defined in patent claims 7 and 8. The Saun*552ders flange or lip only sealingly engages tbe ball 1 on the upstream side when the fluid pressure forces the lip against the ball and never sealingly engages the ball on the downstream side because there is no fluid pressure there to force the lip against the ball. The Saunders sealing ring provides a compression type of seal which depends upon the ball pressing into the material of the ring. The sealing rings of Saunders are substantially triangular in cross section to provide a conical surface which is compressed by the ball to form a fluid tight seal. The lip is provided at the inner portion of each ring and engages the ball on the upstream side when fluid pressure acts against the lip to force it against the ball. The seal of Saunders depends primarily on the contact between the ball and the body of the sealing ring, and the flange or lip sealingly contacts the ball on the upstream side when the fluid pressure increases. Saunders seal lip does not increase in thickness outward in the radial direction as required by patent claim 7 nor does the lip have side faces disposed toward and away from the ball which diverge from each other substantially uniformly outward in the radial direction of the ring as required by patent claim 8. Claims 7 and 8 here in suit are patentable over Saunders British patent 692,085.
16. Defendant urges that patent claims 7 and 8 are not patentable since it would have been obvious under 85 U.S.C. 103 to replace the straight-sided lip of the Saunders British patent 692,085 sealing ring with a tapered lip as shown by the Antonelli U.S. patent 2,348,587. Antonelli discloses a seal construction for sealing the space between a housing and a spherical member in a front axle assembly for armored cars. Dual wiping lips on the sealing element are tapered inwardly and are downwardly compressed against a spherical member through a flexible neck portion of reduced cross section by the seal housing. The lips disclosed by Antonelli are not free to bend in the axial direction of the sealing ring as required by patent claims 7 and 8 but are compressed downward and would not seal or stay on a ball if placed about the passage extending through the ball of Saunders. Tapering the sealing lip of Saunders would improve the sealing action of the lip when the lip is under fluid pressure but would not satisfy the requirement of patent claims 7 and 8 that the lip always *553be in sealing contact or engagement with the ball. Claims 7 and 8 define structure not obvious as a whole by modifying Saunders to utilize the seal element of Antonelli.
17. Blevans patent 2,516,947 was not cited by the Patent Office and relates to a valve seat and valve core for high-pressure use. Figures 1,4, and 5 are reproduced herein. Blev-ans discloses a valve comprising a housing 10 having an inlet opening 11 and an outlet opening 12. A valve core 13 is mounted in said housing and is provided with a flow passage 14. A metal alloy sealing ring 16 is mounted around the downstream opening 12. Sealing ring 16 is provided with two annuli 20 and 21 and with rubber or plastic packing 23 in an annular groove 19 between the annuli. Each of the annuli 20 and 21 projects inward toward the axis of the sealing ring 16 and is flexible enough to undergo limited deflection in the axial direction of the sealing ring. Such deflection is illustrated in exaggerated form in Fig. 5. Each annulus is tapered in cross section and increases in thickness outward in the radial direction of the sealing ring 16, and each annulus has a face disposed toward the core 13 and a face disposed from the core. The Blevans construction includes mechanism for moving the core 13 axially into and out of engagement with the valve seat ring 16. Blevans states that his invention may be applied to any valve in which the face and seat engage axially. Neither the lip 20 nor the lip 21 of Blevans engages the valve core as it is turned from its open to closed position, and the Blevans construction is not concerned with the problem of forming a tight seal between the core and the sealing ring 16 during operation of the valve. The structure defined in patent claims 7 and 8 is novel and unobvious as a whole over the construction disclosed in Blevans patent 2,516,947.
18. Australian patent 126,685 was not cited by the Patent Office and discloses a plug cock comprising a casing made up of end portions and a connecting sleeve having a chamber. A rotatable ball having a passage therethrough is mounted in the chamber. A pair of sealing rings is positioned, one around an inlet opening and one around an outlet opening. Each sealing ring is provided with a portion which projects inward toward the axis of the sealing ring and which con*554tacts the ball. The inwardly projecting portions of the sealing rings may be sharp corners or may be chamfered or countersunk for engagement with the ball. Fluid pressure holds the inward portions of the sealing rings against the *555ball, the latter being mounted in bearing sleeves which prevent axial shifting of the ball under fluid pressure. The Australian patent construction does not provide for axial lip bending or for increasing resistance to such bending. The structure defined in patent claims 7 and 8 is novel and un-obvious as a whole over the plug cock construction taught in Australian patent 126,685.

*554

*55519. Newton patent 2,297,161 was not cited by the Patent Office and discloses a valve having a casing provided with a valve chamber in which a ball is mounted for rotation. The casing is provided with an inlet opening and an outlet opening, and the ball is provided with a passage adapted to be positioned in alinement with or transverse to the inlet and outlet openings. Newton discloses saucer-shaped sealing rings. The ball is truncated at each end of the passage and preloads or prestresses the sealing rings during assembly. The sealing rings are further compressed when the increased area of the nontruncated portion of the ball engages the seat material to flatten the rings against the walls of the valve chamber. The Newton valve ball is free to move axially with fluid pressure causing the entire ring to twist and be compressed by the ball. The structure defined in patent claims 7 and 8 is novel and unobvious as a whole over the construction disclosed in Newton patent 2,297,161.
20. Clade patent 2,762,601, not cited by the Patent Office, discloses seats for ball valves, the seats being formed of polytetrafluoroethylene and including a seating ring plus an adjacent sealing ring of various cross sections. A single sealing ring of rectangular cross section is shown in one modified construction. Clade also discloses valve stem seals of various shapes. None of the seating and sealing rings disclosed in this Clade patent is provided with a lip projecting inward toward the axis, free to bend in the axial direction, and increasing in thickness outward in the radial direction. In the construction illustrated in Fig. 10 of the Clade drawings, the inward edge of the sealing ring is prevented from bending in the axial direction by a boss on the casing. The structure defined in patent claims 7 and 8 here in suit is novel over and not obvious as a whole from the teachings of Clade patent 2,762,601.

*556

ACCUSED' ELECTRIC’ BOAT DIVISION BALL VALVE
21. One of the allegedly infringing ball valves as manufactured by the Electric Boat Division, General Dynamics Corporation, is shown in manufacturing drawings, plaintiff’s exhibit 11. The essential features of said Electric Boat Division ball valve are illustrated in the two figures reproduced herein. Said valve comprises a casing adapted to be connected to a pipeline and having a valve chamber with inlet and outlet openings. A ball is mounted in the chamber and has a port or passage therethrough. A sealing ring is mounted in the chamber surrounding one of the openings. The cross section drawing of the sealing ring shows an outer body portion and an inner body portion, the latter being of reduced cross *557sectional area providing a lip which projects inward toward the axis of the ring and which engages the ball. The ball is rotatable between open position in which the port or passage through the ball is in register with the openings and a closed position. The drawing shows that the sealing ring lip has a rounded surface and two faces, one face disposed toward the ball and the other face away from the ball. These faces diverge substantially uniformly outward in the radial direction giving the inner lip portion a greater degree of flexibility than the outer thick portion of the sealing ring. During assembly the sealing ring lip is prestressed or preloaded and maintains a sealing contact with the ball as the latter is turned from an open to its closed position or vice versa. All of the elements recited in patent claims 7 and 8 are present in the accused Electric Boat Division ball valve and function in substantially the same manner to provide substantially the same result during use.
22. The defendant has urged that the construction of the accused Electric Boat Division ball valve is such that the inner lip portion of the sealing ring does not bend materially and that the seal results from “torsionally twisting” the sealing ring, as described in a later Bass, et al., TJ.S. patent 2,989,990, issued to General Dynamics Corporation in 1961. In torsional twisting, as defined by the Bass patent, the sealing ring is twisted about a circular line representing the loci of points which are the centroids of the cross section of the sealing ring due to the pressure of the ball against the lip of the sealing ring. It is found that the inner portion of the lip of the Electric Boat Division sealing ring has a greater degree of flexibility than the outer portion due to its tapered cross section, and that there is lip bending present in the Electric Boat Division ball valve. Tests conducted on the Electric Boat Division sealing ring at the trial demonstrated that there was both substantial torsional twisting and substantial lip bending. The torsional twisting is additive in nature and is not exclusive of the lip bending defined in patent claims 7 and 8.
23. The second of the allegedly infringing ball valve constructions is identified as the Type P.327, Series 400 manufactured by Worcester Valve Co., Inc., Worcester, Massa*558chusetts. The Worcester valve construction is illustrated in Sanctuary patent 2,963,263 issued in 1960 to Worcester Valve Co., Inc., and by other exhibits. Fig. 4 of the Sanctuary patent drawings and plaintiff’s exhibit 20 are reproduced herein to show the accused construction. The Worcester ball valve includes a casing 10 adapted to be connected to a pipeline and having a valve chamber and inlet and outlet openings; a ball mounted in the valve chamber with a port or passage extending therethrough; sealing rings 20 mounted in the valve chamber, one mounted in the chamber about the outlet opening and the other about the inlet opening, the ball being rotatable between an open position in which the port is in register with the openings surrounded by the sealing rings and a closed position. The infringement issue is whether the sealing rings 20 of the Worcester valve have the lip configuration defined by patent claims 7 and 8 of the patent in suit. Each of the Worcester sealing rings 20 has an inner face 45 which is a spherical area having a radius 47 greater than the radius 50 of the ball and a substantially conical face 38 merging with an inner rounded nose portion 39. When the sealing rings 20 are assembled in the Worcester valve chamber about the inlet and outlet openings, the ball bends the tapered nose portion 39 of the sealing ring 20 from the unstressed cross section shown in plaintiff’s exhibit 20 to the cross section shown in Fig. 4 of the Sanctuary patent drawings. Under fluid pressure, the ball is moved slightly downstream bending the tapered nose or lip portion 39 and compressing a portion of the ring surface 45. The Worcester sealing ring provides combined lip bending and progressive compression sealing between the ball and the seal. This progressive compression sealing is additive in nature to the lip bending concept. The tapered nose portion of the Worcester valve sealing ring 20 functions in substantially the same way to produce substantially the same result as the lip construction defined in claims 7 and 8. The Worcester tapered sealing ring always contacts the ball and increases in thickness substantially uniformly outward in the radial direction. The tapered portion has one face disposed toward the ball and one face disposed away from the ball, and said faces diverge substantially uniformly outward in the radial *560direction as recited by patent claim 8. Tbe tapered portion of ring 20 has a graduated stiffness and is deflected due to preloading and sealingly contacts the ball at all times. The tapered portion is free to bend in the axial direction. The Worcester ball valve includes all the structural elements recited in patent claims 1 and 8 and said elements function in substantially the same manner and produce substantially the same results as the construction disclosed and claimed.

*559

*56024. Both of the accused ball valve constructions include sealing rings in which grooves are provided in the outer peripheral edge of the sealing ring to permit fluids to escape around the sealing ring on the upstream side of the valve. Defendant has urged that patent claims 1 and 8 are limited by their prosecution to a ball valve having lip bending and sealing on the upstream side. Defendant has also urged that since the accused valves do not provide upstream sealing, they do not infringe patent claims T and 8. The prosecution history of the patent in suit shows no intent to limit the claims in suit to either upstream sealing or downstream sealing. Defendant’s contentions in this respect are not supported by the evidence.
25. Summarizing the above findings of fact, it is concluded that claims 7 and 8 of the Freeman, et ah, patent 2,945,666 are valid over the prior disclosures presented by defendant, and that said patent claims have been infringed by the accused Electric Boat Division ball valves and the accused Worcester Valve Co., Inc., ball valves.
26. A trial to establish liability in this case was initially held before Commissioner Donald E. Lane (now Judge ox the United States Court of Customs and Patent Appeals). After completion of the trial and following the filing of the parties’ post-trial briefs and requested findings, plaintiff’s ownership of the patent in suit, United States Letters Patent No. 2,945,666 (hereinafter referred to as the ’666 patent), was put in issue by E. W. Bliss Co. as intervenor in an infringement action on the ’666 patent, in the United States District Court for the District of Massachusetts between Jamesbury Corp. as plaintiff and Worcester Valve Co., Inc., as defendant. In view of the Massachusetts suit, the parties agreed to a stay of proceedings in the present suit, *561after the commissioner’s report had been filed, until ownership of the ’668 patent had been settled in the Massachusetts District Court. In his opinion of May 16,1967, Commissioner Dane found that claims 7 and 8 of the patent in suit were valid and infringed by defendant’s unauthorized use of ball valves manufactured by the Electric Boat Division of General Dynamics Corp. and Worcester Valve Co., Inc.
27. On June 29, 1971, plaintiff reported to this court that after full trial on the issue of ownership, the United States District Court for the District of Massachusetts entered judgment for Jamesbury Corp. (318 F. Supp. 1) and that this judgment had been affirmed by the United States Court of Appeals for the First Circuit (443 F. 2d 205). At the same time, Jamesbury Corp. moved to remand this suit to the trial division for further proceedings and additional findings of fact on an issue raised by E. W. Bliss Co. and commented upon, without deciding, by the Massachusetts District Court, to wit, whether the named inventors of the patent in suit, Howard G. Freeman and Oscar B. Vaudreuil, were joined in a manner irremediably contrary to applicable law. Thus, at 318 F. Supp. 6, fn. 6, the court stated:
If relevant, the court would find that Vaudreuil was added to the application as a spurious joint inventor to shield Jamesbury against any claim by Bockwood that its president and principal shareholder had conceived the invention while a Bockwood employee.
On appeal, the First Circuit noted this finding and James-bury’s strenuous objection that it was erroneous. The First Circuit, after indicating that the finding was clearly dictum and not binding in other litigation, decided that since there was evidence to support it, the dictum could not be said to be clearly erroneous.
In addition, Jamesbury Corp. moved to have the case remanded to the trial division so that additional findings could be made concerning a patent called to plaintiff’s attention by Worcester Valve Co., defendant in the Massachusetts action, during settlement discussions between the parties. The patent, Melichar, et al., United States Patent No. 2,409,220 (hereinafter referred to as ’220 patent), was, according to plaintiff’s remand motion, alleged by Worcester *562Valve Co. to constitute a reference highly pertinent to the validity of the patent in suit. Although defendant opposed plaintiff’s motion to remand, this court, in an order dated October 1, 1971, remanded the case to the trial division to allow defendant to raise in supplemental pleadings the issues of misjoinder of inventors and the effect of Melichar, et al., on the validity of the claims in suit.
28. In supplemental pleadings, defendant raised the defenses of misjoinder of inventors and the effect of Melichar, et. al., on the validity of claims 7 and 8 of the patent in suit. Defendant, as well, also questioned the validity of claims '7 and 8 of the ’666 patent in view of Cross British Specification No. 373,660.
In September 1973, a trial, limited to the two above-discussed issues, was held. With regard to the issue of mis-joinder of inventors, neither side called any witnesses. Instead, each side read into the record portions of the record from the Massachusetts trial on the ownership question, and, as well, portions of transcripts of depositions taken in connection with that trial. On the issue of patent validity, each side called one expert witness.
29. Howard G. Freeman obtained a bachelor of science degree in mechanical engineering from Worcester Polytech-nical Institute in June of 1940. Upon graduation, he was hired by the Bockwood Sprinkler Co. (hereinafter referred to as “Bockwood”) of Worcester, Mass. He was later named director of research, a position which he continued to hold until January of 1954.
Shortly after entering employment with Bockwood, and specifically on August 28, 1940, Freeman executed an employment agreement wherein he agreed—
* * * to give to Bockwood the full benefit and enjoyment of any and all inventions or improvements which he may make while in the employ of Bockwood * * * and all inventions which are made or worked out on the time and at the expense of Bockwood. * * *
Said Freeman further agrees that he will without additional consideration disclose promptly to Bockwood all of the above-described inventions or improvements * * *.
*563During the course of his employment at Rockwood, some 19 United States patents, plus foreign counterparts thereof, issued naming Freeman as inventor or coinventor. Freeman assigned all of his interest in these patents to Rockwood.
30. Freeman, 'as director of research, was primarily responsible for designing and improving all of Rockwood’s products. He also had full authority, without the prior approval of any other company official, to submit ideas which he believed were novel to Rockwood’s patent attorneys.
He was included in the company’s “key man” program under which company executives received compensation based upon business volume and company profits. At the time of his departure, in 1954, Freeman’s compensation was about $25,000 annually.
By the latter part of 1953 the principal products of Rock-wood were sprinkler systems, fire fighting equipment, rescue equipment for airports and ball valves. At that time, the ball valves produced by Rockwood were single seat compression-type valves, and constituted between 8 and 10 percent of its total annual sales.
31. The ball valves manufactured by Rockwood while Freeman was employed there utilized a compression seat on only one side of the ball. These seats were sometimes referred to as “jam seats,” since a seal is formed by the ball being jammed by a spring or other device against the opposing seat. This design, although commercially successful, had the disadvantage of only being able to control the flow of fluid adequately in one direction. The seats sometimes swelled, making the valves leak and difficult to turn.
From 1945 on, Rockwood’s customers occasionally requested ball valves that were capable of controlling the flow of fluid in either direction. Rockwood, however, never manufactured such a valve while Freeman was its director of research.
32. In the fall of 1953, while still director of research, Freeman became dissatisfied with his position at Rockwood and discussed the possibility of going into the ball valve manufacturing business with a personal friend, Saul Reck. After a number of discussions, Reck, who in the past had financed several new business ventures, obtained commit*564ments of about $60,000 from several potential investors. It was contemplated that Eeck would manage the financial aspects of the new business, while Freeman would contribute his engineering and design talents. Investors were apparently willing to take a chance on this new business venture on the understanding that there was a good market for double seated ball valves that were made from hard brass bar stock and had soft seats of rubber, nylon, teflon, or similar material.
33. On January 13, 1954, Freeman went to William J. Carroll, Eockwood’s president, to express his dissatisfaction with his compensation and status at the company. Freeman indicated that he would resign “if something couldn’t be done” about it. Freeman was told that he would be given an answer shortly. Failing to hear from Mr. Carroll by January 20, 1954, Freeman sent him a letter of resignation suggesting that his effective resignation date be January 30, 1954. The letter went on, however, to indicate Freeman’s willingness to serve an additional reasonable period or to have the resignation take effect sooner at Eockwood’s option. On January 25, 1954, Mr. Carroll called Freeman to his office. As a result of the meeting, it was agreed that Freeman would leave that afternoon. Freeman’s employment and duties at Eockwood ended on that day.
34. Upon leaving Eockwood on January 25,1954, Freeman called Eeck and told him to do what was necessary to obtain the financing for the new company which they had earlier discussed. Freeman and Eeck arranged with Boston counsel for the formation of the new company. Jamesbury Corporation’s Articles of Incorporation were drawn up and dated January 29, 1954. The contributions by the initial investors were made by checks that had been postdated to February 2, ■1954.
■ 35. On February 1, 1954, Freeman commenced a series of drawings and sketches of valve parts. Some of these were undated, but none were begun before February 1, 1954. It took Freeman several days to complete the drawings and he did not complete any of the drawings in a single day. While drawing and sketching during the first or second week of February, Freeman commenced drafting a written description of three ideas he was working on. One of these *565ideas was for a new valve seat. The written statement describing Freeman’s new valve seat was completed before February 23, at which time the written description along with five illustrative sketches were taken to his patent attorney in Boston. The written description read in part:
The new valve seat has both a flexible sealing surface and a non-flexible surface to absorb compression load. By utilizing the design as shown, the lip seal is pre-compressed before the ball surface strikes the non-flexible surface. The intent of the design is to maintain a definite space between the seat and the ball to allow for swelling.
36. On the basis of this material, Freeman’s patent counsel prepared a draft of a patent application containing four claims and a drawing consisting of four figures. The claims covered Freeman’s V-notch design. The drawings specifically showed a seal configuration which included a “V-notch,” substantially as shown in Fig. 5 of application Serial No. ’188, that was carved into the seat in order to provide for greater flexibility. The oath accompanying the draft named Freeman as the sole inventor of the subject matter claimed therein.
On April 27, 1954, this draft was forwarded to Freeman for review but there is no indication that Freeman ever *566signed it or that it was ever filed in the United States Patent Office. As such, the claims contained in this draft can only be viewed as disclosing the attorney’s understanding of Freeman’s V-notch valve seat.

*565

Figure 5 of the ’188 application

*56637. In the latter part of March 1954, Freeman set up a lathe in space he had rented in Worcester, Mass., and started to make parts for his valve. Shortly thereafter, he also set up apparatus to test the prototype valves he had made. Freeman’s initial efforts at producing quality valves were unsuccessful and he continued to experiment with various modifications of his original design. He was particularly concerned that the seats would tear after only a few operations of a valve.
38. Oscar Vaudreuil, now deceased, had a machine shop in Worcester, Mass., which supplied Jamesbury Corp. with parts and services during 1954. Since Jamesbury Corp. had little cash to pay for these goods and services, Vaudreuil accepted stock in the corporation in lieu of money. Vaudreuil observed some of the tests being performed by Freeman. In connection with the seat tearing problem which Freeman’s design was experiencing, Vaudreuil suggested that a small part of the metal casing behind the flexible valve seat be chamfered or cut away. This part of the metal casing is represented by 44 in Fig. 9 of the ’666 patent. Freeman tried *567out this suggestion and it eliminated the tearing of the valve seat that had plagued earlier valves by enabling the lip of the valve seat to move more freely.

*566

Figure 9 of the ’666 patent

*56739. As a result of Vaudreuil’s suggestion, Freeman concluded that the necessary lip flexibility could also be obtained by cutting away one of the two lips of his V-notch valve seat in lieu of chamfering the metal casing. This modification of the valve seat was further refined into the design shown in Fig. 5, see finding 10, and has eliminated the valve seat damage that was prevalent in Freeman’s original design.
40. In May 1954, Freeman returned to his patent attorney in Boston and described the changes that he and Vaudreuil had made to the valve. Freeman asked his patent attorney whether Vaudreuil was to be included in the patent application as a coinventor and was told that he was.
The patent attorney revised the previously prepared draft, later filed on June 11,1954, as Patent Application Serial No. 436,188 (hereinafter referred to as the ’188 application), by including therein the embodiments suggested by Vaudreuil and Freeman’s modification thereof. More specifically, Fig. 8 of this application showed the changes which Vaudreuil contributed while Fig. 7 showed Freeman’s equivalent modification of removing one of the two lips of the “V-notch” valve seat without chamfering the abutting casing.
41. An analysis of the original 10 claims contained in the joint ’188 application indicates that claims 1 through 8 are sufficiently generic to read on the Freeman V-noteh seat, as well as upon the Freeman-Vaudreuil joint design. Claims 9 and 10 covered the Freeman-Vaudreuil embodiment shown by Figs. 7 and 8. The oath accompanying the ’188 application named Freeman and Vaudreuil as joint inventors.
42. As a result of the first amendment to the ’188 application while it was pending in the Patent 'Office, Freeman and Vaudreuil canceled claims 6,7 and 8 of the original 10 claims. By amendment of August 26,1957, Freeman and Vaudreuil canceled all of what remained of the original 10 claims and added new claims 11-13. As explained in the remarks accompanying the amendment, “Claim 11 corresponds in substance to Claim 10 * * Claim 10, as hereinbefore stated, originally read on the joint Freeman-Vaudreuil invention *568as shown by the Fig. 7 embodiment of the application, see •findings 40 and 41. Similarly, since new claims 12 and 13 were dependent upon new claim 11, there can be no doubt that the joint inventors limited all of the new claims to their joint invention.

Figures 7 and 8 of the ’188 application
43. On February 14, 1958, the joint inventors filed a continuation-in-part application, Serial No. 715,372 (hereinafter sometimes referred to as the ’372 application), with the Patent. Office. The drawings of this application illustrated only the joint Freeman-Yaudreuil invention, and did not illustrate the original Freeman Y-notch design. Specifically, Figs. 5 and 6 of the ’188 application, which illustrated the Freeman Y-notch design, were not included in the ’372 application. In addition, Figs. 2 and 4 of the ’188 application were modified to eliminate the Freeman V-notch seat, see Figs. 2 and 4 of the patent in suit. Furthermore, new Figs. 5 and 7, depicting only the joint invention, were added. Fig. 9 of this application is substantially identical to Fig. 8 of the ’188 application.
The specification of the ’188 application was extensively revised and the entire emphasis shifted. The new specification dealt almost exclusively with the joint invention, and *569relegated tbe V-notch design to a four sentence discussion. As a result of the inclusion of language such as “free standing lip,” all 10 claims of the new application read only on the joint invention, and not on the sole Freeman invention.
44. The Patent Office, on March 27, 1958, indicated that claims 1 and 3 of the ’372 application were—
* * * unpatentable over the claimed subject matter of applicants’ copending application, Serial No. 436,188 which has been indicated as allowable * * *.
In addition, the Patent Office rejected the remaining claims in the application—
* * * on the claimed subject matter of applicants’ co-pending application, Serial No. 436,188 indicated as allowable in conjunction with Clade [prior art Patent No. 2,792,196].
45. Although by subsequent- amendments, see the amendment of October 6,1959, the applicants presented new claim 14, which subsequently issued as claim 7 of the patent in suit, without including the term “free standing lip” or “free standing deflectable lip,” the claim cannot be interpreted to read on the original Freeman V-notch seat because to do so would permit the applicants to cover subject matter that was willingly relinquished during the prosecution of the ’188 and ’372 applications through the Patent Office. On July 19, 1960, the ’372 application issued as United States Letters Patent No. 2,945,666.
46. In view of the actions by the joint inventors in prosecuting the ’188 and ’372 applications, it is concluded that the claims in suit, claims 7 and 8, read on the jointly made Freeman-Vaudreuil invention disclosed in the ’666 patent.

Prior Art

47. In 1954 and prior thereto, the ordinary valve designer was either a university graduate in mechanical engineering or a high school graduate who had obtained considerable practical experience under the direction of graduate engineers.
48. Defendant also contends that the claims in suit are invalid since they would have been obvious to one of ordinary skill in the art under 35 U.S.C. 103 in view of the disclosures *570of prior United States Patent No. 2,409,220 issued October 15, 1946, on an application filed May 13, 1943, to Joseph F. Melichar and Wilton Margrave, entitled “Sump Selector Valve,” and British Patent Specification No. 373,660, accepted June 2, 1932, entitled “Improvements in the Sealing and Lubricating of Valves for Internal Combustion or other Engines and Pumps” by Boland C. Cross.
49. The Melichar patent discloses a sump selector double check valve designed to prevent air from the higher end of a partially full airplane fuel tank being fed into airplane engines during flight. Figs. 1 and 4 are reproduced herein. As shown in Fig. 1, the valve comprises a casing 5 which is open at both ends. Casing 5 contains an outlet opening 6 that is perpendicular to its longitudinal axis. Inlet openings are provided in the respective ends 7 of the casing. Within each end of the casing is formed a ball valve chamber 8. Central flow chamber 9, having circular openings 10, is disposed in the center of the casing betwen the ball chambers to permit communication therebetween.
Circular openings 10 are provided with seat recesses which are undercut as at 12 to provide an overhanging shoulder. The inner edge corners are rounded, as at 13, in order to prevent damage to the flexible lip of the seat rings. A valve seat ring 14 formed of rubber or other yieldable material is mounted in each recess 11. The Tings are removably held in the recesses by a metal mounting or keeper ring 15, which in turn is provided with an inwardly directed keeper flange 16.
Each seat ring 14 includes an obtusely angularly recessed face portion 16, see Fig. 4, which results in the provision of a line contact bumper seat 19 and a relatively thin, very flexible lip 20 which projects into the circular openings 10. Each flexible lip is positioned so as to present a line contact seat shoulder 21 toward the respective ball chamber 8. Within each ball chamber 8 are ball guide ribs 23 which serve as guides for the rollably mounted ball valves 22. By reason of the guides, a ball valve rolling against the ring seat will first engage in line contact with the flexible lip 20 as at 21 of Fig. 4. If the tilt of the casing is very slight, the liquid seal will be affected by this contact, but if lip 20 *571is deflected to a sufficient extent, as when there is more than just slight tilting, the ball will next engage the less readily yieldable bumper seat shoulder 19. If this contact is insufficient to form a seal, the ball will next contact rigid support shoulder 17 to form a seal. Bumper seat shoulder 19 and rigid support shoulder 17 limit the movement of the ball into lip 20 and prevent sticking of the ball in the seat ring.

Figures 1 and 4 of the *220 patent

The balls 22 are controlled by pendulum 34 in such a maimer that at least one check valve remains open to provide fuel to the airplane engine.
50. The claims at issue, see findings 5, 10 and 11, call for a sealing ring which has a lip that is free to bend in the axial direction of the ring. In this manner, the lip of the patented ball valve bends with respect to the remainder of the sealing ring. As a result of prestressing, the lip flexes into sealing *572contact or engagement with the ball at all times, even when the ball is being rotated. The lip projects inward, see Figs. 5-7 accompanying finding 10, and the tapered cross-sectional shape in the radial direction results in its having a graduated stiffness. The ball is provided with a truncated fluid passage port, such that reduced ball pressure occurs against the seat when the fluid passage port of the ball is aligned with the opening in the casing. However, when the valve is closed, by a quarter turn of the ball, the non-truncated portions of the ball press into the seat to provide a fluid tight seal.
51. The Melichar, et al., valve differs significantly, both in its operation and design, from the Freeman, et al., valve. The Melichar lip is purposely designed to be thin and very flexible and was not intended to be used with a ball having a fluid passage port. Use of a thin, flexible Melichar lip on the upstream side of a ball as shown in the ’666 patent could result in the lip being forced into the port when the ball is in the open position. Upon movement of the ball into its closed position, the lip would then be susceptible to being pinched or cut. Thus, while the Melichar, et al., valve was intended to control fluid flow in only one direction, the Freeman, et al., valve can control flow in both directions.
Melichar, et al., was not faced with the problem of insuring a fluid tight seal to a flow which could be coming through the port of a ball in either of two directions. Moreover, since Melichar, et al., was not concerned with a quarter turn ball valve, no attention was given to insuring that the seal would be capable of properly operating with the continuous sealing contact required by the ball valve disclosed and claimed in the patent in suit while the ball is being rotated from an open to a closed position or vie versa. See finding 10.
52. On the other hand, prestressing is not necessary or required in the totally open or totally closed double check valve of Melichar, et <ü. In fact, while the Freeman, et al., lip is designed to always be in contact with the apertured ball in both its open or closed positions, the solid ball of Melichar, et al., is only in contact with the lip in the closed position. Moreover, the Melichar, et al., lip is not designed or intended to support the ball, in the maimer required by *573the Freeman, et al., lip in the open or closed position of tlie valve.
53. The structure defined by claims 7 and 8 of the patent in suit is novel and unobvious, when considered in its entirety over the double check valve disclosed in Melichar, et al., patent No. 2,409,220.
54. The Cross British Patent Specification discloses a continuously rotating plug valve used in internal combustion or other engines, which is designed to alternately connect the cylinder of that engine to an inlet and exhaust manifold. Figs. 3 and 7 are reproduced herein.
The device contains a metallic bearing or liner 1 which is pressed or otherwise fastened into a valve housing 2, and in which a valve 3 rotates to perform its work of opening and closing port 4 in cylinder head 5. This liner 1 has a hole 6 in its wall to register with the port 4. The liner 1 at the periphery of hole 6, and for some distance around it, is shaped with a lip 8 which presses slightly inwards toward the working face of the valve 3. By pressing the liner 1 inwards toward the valve 3 adjacent to the edge of port 4, a slight gap 7 is produced between liner 1 and the valve housing 2. This permits the gas pressure in the cylinder to get underneath the liner for a short distance adjacent to the port and press the edge of the liner against the valve. This also enables the valve to have a good working clearance in the liner, and guarantees, regardless of the position the valve assumes in the clearance of the liner, that lip 8 of the liner will resiliently follow the surface of the valve. A sufficiently gas-tight valve, for all practical purposes, is thus achieved.
Fig. 7 is a detailed view of one of the possible configurations for lip 8.
55. As understood, the Cross patent discloses a cylindrical liner which entirely surrounds a cylindrical valve, and is provided with an oval opening along one surface to register with the port of a cylinder. The cylindrical liner is made of cobalt chrome steel so that it can be used as a bearing surface for the valve. At the same time, the liner material is selected to be of sufficient elasticity to allow a resilient lip surrounding the oval opening to be pressed against valve 3. This cy*574lindrical liner is to be distinguished from the seat disclosed by Freeman, et al., which is of a narrow circular configuration. The Freeman, et al., seat is shaped in such a manner that its beveled sides terminate in a lip that is biased inwardly and axially movable. Sealing is initially provided by line contact between the lip and ball. Upon additional fluid pressure, the ball contacts a beveled surface to enhance the sealing ability of the seat. The Cross patent only teaches the use of a lip to seal.
In addition, the Cross and Freeman, et al., seats are designed to achieve substantially different results. Particularly, the Freeman downstream seat achieves maximum contact between the ball and the lip when no fluid is flowing through the ball port, i.e., when the valve is closed. In contrast, the seal of the Cross invention achieves its greatest contact between the lip and the valve when gas is flowing through the cylindrical port into the valve 3.
Moreover, nowhere in Cross is there any disclosure of a sealing ring such as shown in the patent in suit which has a lip position that can be prestressed to cause it to flex into sealing engagement with the inlet and/or outlet ports of a quarter turn ball valve. Cross, furthermore, does not disclose or teach providing his lip with graduated stiffness by increasing its cross-sectional shape in the radial direction of the seat. Indeed, the Cross device does not appear to be subjected to any degree of movement as the ball of the ’666 patent may be subjected to in its closed position. Thus, no thought was given by Cross to having the seat be able to support the ball during such periods of increased load. This is done in the ’666 patent by the ball flexing the lip to the point where the ball will contact the oblique surface 25 times, see finding 10 and Fig. 7.
The above differences in operation, results and structure, coupled with the fact that the Cross patent relates to internal combustion engines, make it highly unlikely that a person having ordinary skill in the art would have considered modifying Cross to obtain the Freeman, et al., seat.
56. There are a number of other differences between the Cross device and that of the patent in suit. In the first place, the Cross device does not relate to ball valves. The Cross *575device rotates continuously in the same direction to open and close a port. On tlie other hand, the ball valves of the patented invention open and close by rotating a quarter turn in either direction. Furthermore, the Cross reference discloses a liner and valve arrangement that are in continuous contact to form a seal. In this arrangement, the valve is supported by the bushing in which the cylinder rotates *576rather than by the lip as in the Freeman device. Moreover, Cross did not intend that his device be capable of handling continuous flow, whereas the Freeman valve is capable of such operation.
*575Figures 3 cmd 7 of the Cross patent

*57657. In addition, the valve seats shown by both Meli'char, et al., and Cross are not self-compensating with respect to wear and temperature changes as is the Freeman, et al., seat. Bee finding 10.
58. In view of these major differences in the construction of the devices, as well as their method of operation, it must be concluded that the devices defined by claims 7 and 8 of the patent in suit are not rendered obvious by the Cross reference either taken alone or in combination with’Melichar, et al.
SUMMARY
Claims 7 and 8 are valid over the prior art. Freeman and Vaudreuil are deemed to be joint inventors of.,claims 7 and 8. !
CONCLUSION OE LAW
Upon the foregoing findings of fact, which are made a part of the judgment herein, the court concludes as a matter of- law that claims 7 and 8 of United States Letters Patent No. 2,945,666 are valid and have been infringed by the defendant’s unauthorized use of ball valves produced by the Electric Boat Division of General Dynamics Corp. and by Worcester Valve Co., Inc., that plaintiff is entitled to recover reasonable and entire compensation therefor, and judgment is entered to that effect. The amount of recovery will be determined pursuant to Buie 181 (c) (2).

 Now Judge of the United States Court of Customs and Patent ADDeals.

 153 USPQ 672 (Trial Div., Ct. Cl. 1967).

 This opinion is supplemental to that of May 16, 1967, and a thorough understanding of the facts requires a careful review of former Commissioner Lane’s prior opinion. Moreover, because of this relationship, the findings of fact in this report begin with No. 26 and depend upon the findings in the earlier report.

 More exactly, the order stated In pertinent part:
“(1) defendant shall have 45 days from this date within which to file a supplemental answer, setting forth such defenses as it may wish to present on the question as to whether the inventors of the patent in suit are joined together in a manner irremediably contrary to applicable law, plus such defenses as it may wish to present pursuant to 28 [35] U.S. Code §§ 102 and 103, as to the effect of the Melichar patent on the validity of the patent in suit.
“(2) Plaintiff shall have 30 days after the filing of defendant’s supplemental answer within which to file plaintiff’s responsive pleading.
“(3) The case is remanded to a trial commissioner for a trial and report of his findings of fact and conclusions of law on the issues that may be raised by such supplemental pleadings, and
“(4) Defendant’s motion to retry the issues of fact and law previously tried before and reported by a commissioner of this court is denied.”

 Defendant’s contention, that plaintiff’s failure to call the attorney as a witness gives rise to a presumption that the attorney’s testimony would have been detrimental to plaintiff, is found to be unpersuasive. During pretrial discovery, the attorney was deposed by defendant. Moreover, defendant could have called the attorney as a witness at trial if it so desired, under these circumstances, it is impossible to presume that the attorney’s testimony would have favored defendant and been detrimental to plaintiff.

 35 TX.S.C. § 103 provides:
“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. Patentability shall not be negatived by the manner in which the invention was made.”

Findings 1 through 25 were made bj- (then) Commissioner Lane and 26 through 58 by Trial Judge Colaianni.