Full opinion text
WATKINS, Senior District Judge. This is an action brought by Diamond International Corporation (hereinafter sometimes “Diamond” or “Plaintiff”) against Maryland Fresh Eggs, Inc. (hereinafter sometimes “MFE” or “Defendant”) for alleged infringement of United States Patent 2,990,094 (Reifers ’094) issued June 27, 1961, on a continuation of a copending application filed December 16, 1953, which was in turn a continuation-in-part of an application filed May 24, 1952, for a “Molded Pulp Egg Carton.” It is a product patent. The Patent Office has determined that Reifers ’094 is entitled to the filing date of May 24, 1952. Dolco Packaging Corporation (hereinafter sometimes “Dolco”) by agreement dated June 26, 1969, undertook to save MFE harmless with respect to Diamond’s claim in this action; its defense is open and avowed; and it has engaged and is paying the (very able) attorneys who are defending MFE. It is jointly owned by Olson Brothers, Inc. (hereinafter sometimes “Olson”) and Dow Chemical Company (hereinafter sometimes “Dow”), neither of which is a party to this suit. Jurisdiction and venue are admitted and were established. In Diamond International Corporation v. Walterhoefer, 289 F.Supp. 550 (D.Md.1968) (hereinafter “Walterhoefer”), the author of this opinion held Reifers ’094 to be valid and infringed. No appeal was effected to the United States Court of Appeals for the Fourth Circuit. Plaintiff, of course, contends that the Walterhoefer decision is controlling. Defendant (equally), of course, contends that it is not. In general, Defendant urges that the decision in Walterhoefer was probably wrong, but that even if it were not, subsequently developed additional information, including additional patents; later decisions with respect to combination patents and fraud on the Patent Office; and the physical and geometrical properties of the accused structure should now lead to a different result. Alternatively, Defendant contends that Reifers ’094, if valid, is so limited that it does not read on the accused device. Plaintiff counters that the accused device is the equivalent of that claimed in Reifers ’094. This litigation also has been vigorously contested. The claim in suit read as follows: “1. In an integral and nestable egg carton made of relatively flexible molded pulp, a cellular tray portion having a front side, a rear side, and two ends, an inverted dished cover hinged to said tray portion, means for latching said tray portion to said cover with a latch located above said tray portion and extending completely through said cover from the inside to the outside, said tray portion having its front side strongly tied to its rear side by a plurality of spaced cell-forming partitions extending generally parallel to said tray portion ends, said partitions acting as means for preventing spreading of said front side from said rear side, said tray portion including egg cells adjacent but below the latching means, said inverted dished cover having a planar top, a front side, a rear side, and two ends, said front side being connected to said rear side only by said two ends and said planar top so that the front side is relatively flexible and is not rigidly tied to said rear side intermediate the ends of said front side of said cover having an opening formed therein through which the latch is adapted to extend completely from the inside to the outside, said dished cover being hinged to «aid tray portion along its rear side, a latch holding flap hinged to the front side of said tray portion, the hinge line connection of said cover with said tray portion and the hinge line connection of said latching flap with said tray portion being maintained parallel by said tying partitions even when the tray portion is loaded with eggs, said latch on said latching flap being located on one side of said tray portion which is opposite to the side where the cover is connected to the tray portion so that both the cover and the latching flap are each connected to the tray portion when the carton is open, said molded pulp egg carton being integrally formed with the latching flap, the upper edges of the two sides and the two ends of the tray portion, the upper edges of the two sides and two ends of the cover generally in the same plane and with the latch extending downwardly from the underside of the latching flap which is hinged to the front side of the tray portion and said latch being relatively close to the tray portion as compared with the opening in the front side of the cover which is relatively remote from the tray portion; when the tray portion is loaded with eggs and the latching flap is turned upwardly and the cover portion is rotated in a direction to telescope over the latching flap, the two hingelines are relatively immovable but the front side of the cover may flex, whereby the loaded egg carton may be latched by simply rotating the latching flap upwardly and inwardly and rotating the cover upwardly and around the latching flap while the structural features maintain the geometric relation of the latch on the latching flap to the opening in the cover until the front side of the cover engages the latch on the latching flap and is cammed thereover until the latch on the latching flap registers with the opening in the front side of the cover whereupon the latch passes through the opening in the cover from the inside to the outside to effectively latch the carton. “2. A nestable molded pulp egg carton in accordance with Claim 1, wherein the opening in the front side wall of said cover extends to the planar portion thereof and the latch on said latching flap is near the edge thereof which is remote from the hinge connection of the latching flap with the tray portion.” FORMATION OF CARTONS Plaintiff’s cartons are integrally produced by a process of secretion of liberated wood or waste paper fibers, by suction imposed within a die of desired configuration, upon the exterior of the die. Defendant’s cartons are of foamed polystyrene. The process begins with solid polystyrene in bead form. The beads are thermoplastic, and become a fluid consistency as heat is applied externally to an extruder. A gas (Freon) under high pressure is charged into the molten polystyrene in the extruder and diffuses into the .polystyrene. Subsequently, the mass is partially cooled under the maintained pressure, and the mass is squeezed or extruded continuously out of a narrow circular annulus into the atmosphere in the form of a tube. Upon release of pressure on extrusion, the diffused gas, aided by the prior incorporation of a nucleating agent, forms a myriad of tiny bubbles in the tube. The tube passes over a cooled mandrel which expands the diameter of the tube and coincidentally causes the tube material to be stretched circumferentially, building what is called transverse axial orientation into the material and strengthening it. Coincidentally the tube is subjected to longitudinal stretch by means of pull rolls, which also improves the • toughness of the material. The moving tube is slitted longitudinally by a stationary knife at a point beyond the stretching mandrel. The slitted tube is then laid open as a continuous flat sheet and is rolled upon itself as roll stock. To make an egg carton, the flat sheet material fed from the roll is led to a thermoforming machine in which it is gradually reheated to render it thermoplastic, but without bursting the contained bubbles. When suitably thermoplastic, a length is advanced to a position between chilled or cooled dies having non-porous mating faces of the desired egg carton shape. These dies, brought toward one another, deform the sheet. The cooled dies cool the thermoplastic sheet material so that it becomes immobilized. The next step is the punching of holes or apertures in the cover for the reception of lugs formed by the dies. Finally, the excess marginal portions of the sheet are trimmed by cutting dies which separate the formed cartons from the sheet margins. The trimmings and aperture punchings are reground and recharged to the extruder. The Court’s comments by way of partial summary were as follows: “It seemed to me that the physical and mechanical procedures at Palmer and Lawrenceville were quite different, although each seems to involve a molding process. Palmer is a molding by agglomeration of disassociated particles, which are then dried and sometimes pressed, and in that sense, perhaps, thermo-refined. (Tr. p. 600). “The molding at Lawrenceville is accomplished by softening sheets, then forming cartons by dies ‘deforming’ the flat sheets . . . (Tr. p. 600). “I also noticed as we were coming up that there was some differentiation. In Palmer, a defoamer .is inserted, while at Lawrenceville, a foam generator is considered to be indispensible.” (Tr. p. 603).” VALIDITY Defendant urges that the decision in Walterhoefer is not controlling, on a number of grounds: 1. Koppelman Patent No. 2,-093,280, issued September 14, 1937, on application filed December 6, 1934, for “Self-Locking Carton and Packing.” a. In Walterhoefer, Koppelman was urged as a defense under 35 U.S.C. Section 103 — obviousness. In this case the Defendant vacillates in its briefs from a claim of anticipation under 35 U.S.C. Section 102, to anticipation under Section 103 if coupled with another patent, or other patents. However, in the final arguments Defendant admitted, albeit reluctantly, that Koppelman was not an anticipation. Koppelman was fully and carefully considered in Walterhoefer (289 F.Supp. 559-561) and by the Patent Office Board of Appeals (289 F.Supp. 561), and the argument repeated here, was rejected that the results of Reifers could be reached simply by inverting Koppelman. As was pointed out in Walterhoefer, Koppelman stressed and relied upon the weight and pressure of the eggs in effecting and maintaining the closure of the carton as described in the patent. The court stated (289 F.Supp. 561): “Certainly gravity could not be inverted with the inversion of the carton, and ‘weight and pressure of the articles in the carton’ could not be employed in part to hold the closure.” The Court is unaware of any relevant change in the operation of the laws of gravity since the Walterhoefer decision. b. This Court also stated in Walterhoefer (289 F.Supp. 560) that: “ . . . there was no evidence that Koppelman ’280 had ever been constructed, or that any one had ever seen a physical embodiment of such a structure, . . . although there was uncontradicted affirmative evidence that it could not be commercially made, and if made would be inoperative . . . ” It is not believed that Defendant challenges the accuracy of that statement on the basis of the record before the Court at the time it was made. Defendant does claim that subsequently discovered evidence shows “that a molded pulp carton having cooperative lugs and apertures was made commercially according to the disclosure and teachings of Koppel-man . . . ” This is based upon the testimony of Ralph A. Farnham, and the exhibits produced by him. Because Defendant’s position as to newly discovered evidence is based solely upon the testimony of Farnham, and because the Court was initially misled by Farnham’s testimony, his testimony in court, and subsequently by way of deposition will be summarized in more than usual detail. In his direct examination in court, Farnham testified that until his retirement some twenty-five years ago he had been in charge of manufacturing at the Herkimer, New York plant of International Paper Company, under Read, General Manager. Among other things, it produced molded pulp egg “flats”. He produced a carton made at Herkimer about five weeks before trial. (Defendant’s Exhibit 94). He testified that he became familiar with the Koppelman “patent” in 1934-35, “and then we put it on the machine, the latter part of 1937 . . .” (Tr. p. 2025). “This happens to be an egg carrier of personally my own design . . .” (2026). It related to figures 1, 2 and 5 of the Koppelman patent (2025). To manufacture Defendant’s Exhibit 96, Farnham “went to the paper mill in Herkimer and dug up one of the old dry heads that I used years ago on the machine.” (2028). In explaining how the dry head was used, Farnham testified: “Q. And how did you use it? “A. We put fine wire, we stretched fine wire over the dry head and in order to do that we had to anneal it, of course, three times, and after we put it on we sewed it on with fine threads, then we fastened it on to a wooden suction box, the head, itself, with a suction hose on the back. We turned it over and stuck it down into a vat of moving pulp which we kept agitated with a paddle, pulled it out, took the clamps off, and took the casting with the egg carrier on it and put it up in front of an electric fan and dried it.” (2031). With respect to the holes in the cover, Farnham replied that they were blanked off in %th inch squares. In response to a question by the Court, Farnham testified that the blanks satisfactorily made the holes and that it was not necessary to do anything in the way of blowing or wiping, or anything else to perfect the holes. (2062). Farnham’s testimony was unclear as to the length of time over which these cartons were manufactured, on occasion indicating that it was during the years 1937-8-9-40 for periods of not less than three months at a time; for three years; they ran “a small number of them” (2059); he could not say even approximately how many three month periods were run (2024), but production was in the millions (2058). He knew they were “going out” because customers could not get enough printing on them. (2043). The only use testified to by Farnham was for handpacking the eggs from his own chicken farm. They were put into the “flap side of the carton”, the flap going up under the cover (2036). He had no knowledge as to whether or not Defendant’s Exhibit 94 was ever automatically filled or closed by machinery. (2062). When demonstrated in court, the top of the egg section of Defendant’s Exhibit 94 appeared to be one-half inch below the top of the cover section, so that no locking occurred. Farnham’s answer was that “When the eggs are in there, it pushes out, so they lock.” Moreover, being made on the dry head, it was too small “for a regular sized egg.” (2063). Plaintiff made a timely motion to strike Farnham’s testimony as not the best evidence for failure to produce the “forms” from which the cartons were made. The Court, under the impression that the only change made to the dry head was stretching wire over it, and that with this addition it functioned satisfactorily unfortunately overruled the motion without conditioning it upon the dry head actually used being produced in court. Testimony was concluded the day after Farnham testified, and the case was closed, except for the filing of transcripts and briefs, and final argument. About six weeks thereafter, Plaintiff took Farnham’s deposition and filed a motion to reopen on the ground of newly discovered evidence. After a hearing, the motion was granted, and Famham’s deposition was filed. The deposition contained some startling information. Although the aluminum heads had been difficult to find, and were not his, Famham melted down the one he allegedly used “shortly after I got back from Baltimore . . .” (Dep. 54, 20) and made plaques from it. In the course of the deposition, in Farnham’s presence, counsel for Plaintiff stated that in an interview before the deposition Farnham had told him that the dry heads “were taken down to Baltimore.” (Dep. 41). There was no denial as to the accuracy of counsel’s statement. Counsel for Defendant denied that they had ever seen the dry heads. This opinion has already set forth the exact language of Farnham when asked how he used the dry head. The only modification to which he referred was stretching, annealing, and sewing fine wire over the dry head. (2031). Much more elaborate procedure, with one extremely important addition, was detailed in the deposition. Four metal strips were used to hold the fine wire onto the casting (Dep. 13); two crude wooden forming tools were used to shape the wire (Dep. 14-17); the dry head had no flap with buttons on it; this part was added (Dep. 43) and the ends were carved (Dep. 52). The head Farnham used “was used before we designed the one with the flap.” (Dep. 45). In contrast to his testimony in court that the holes were satisfactorily made in the cover, and that it was not “necessary to do anything in the way of blowing or wiping, or anything else to perfect the holes” (2062) in his deposition he said “and the square holes, here, we trimmed them with a knife. When the feather edge went in the pulp went underneath those. We trimmed those . . . with a knife when the stock would go underneath the thing a little bit.” (Dep. 50). This Court entertains grave doubts as to the reliability of any of the Farnham testimony, or that the supposed Koppel-man carton (Defendant’s Exhibit 94) was ever made. The dry head used had regularly been used for a non-lockable carton. Even if Defendant’s Exhibit 94 were ever made, there is no evidence that it was ever made, or used, commercially. Its construction made it unsuitable for automatic loading or closing — indispensable requirements for a satisfactory egg carton. Moreover, even if used, it could serve its purpose of remaining locked until manually opened, only so long as at least the front row was completely filled with eggs. Koppelman ’280 revisited does not incline, much less persuade, the Court to change its conclusion and ruling in Walterhoefer, 2. Cox Patent 2,517,465 (’465). Cox Patent ’465 for Molded Pulp Carton issued August 1, 1950, on application filed September 20, 1943. It was extensively considered in Walterhoefer. Cox ’465 discloses (a) a locking flange 22 hingedly connected to the upper edge of the front wall of the tray section; (b) a locking flange carrying locking tabs 24 adapted lockingly to engage slots or openings 21 from the outside in, the engagement occurring above the top of the tray section; and (c) the location of the tabs when in locking engagement “preferably” being such that the “locking tabs will be partitioned between adjacent eggs”, although it is by no means clear that this would be the case in the structures shown in Figures 5 and 7. Defendant asserts that it would be “an affront to the intelligence” of any person “to think that he would not be smart enough to see that the tongues and apertures were intended and positioned to be interengaged”; and that this could be done with the flange on the outside or on the inside of the cover. Aside from the structural changes that would be required, and the express teachings of the patent, it would not be satisfactory to try to fasten Cox '465 from the inside out. (a) Cox, the inventor, realized the impracticality of the carton even making the closure from the outside in. On paper the idea seemed good, but when he saw the actual construction he recognized that “it was completely impossible.” He doubted that a machine could be developed to insert the tabs. The tabs when manually inserted tore off; and the front flap would bow outwardly even if the tabs were inserted. In fact, even at the time of invention Cox was so uncertain as to the practicability of the lock that he disclosed alternative means of locking the flap to the front wall by thermoplastic adhesive. Cox’s summation was that “This carton was completely inadequate to meet any of our commercial requirements, and never went into commercial use.” (b) If it were doubtful that automatic closing could be effected where the tabs were inserted from the outside, it would be even, and much, more difficult to devise a machine that could automatically effect a closure when the tabs were to be inserted from the inside out. It is much simpler to bend the tabs inwardly from the outside than to bend them outwardly from the inside. The flap would have to be pushed very far in as the top came over. The flap would have to be built with a reverse curve so that after insertion the tabs would curl back onto the face of the lid; otherwise the tabs would be projecting out, and would be torn off in ordinary use. Cox ’465 does not make Reifers ’094 obvious. It emphasizes the merit of the simple, but completely effective, Reifers carton. 3. Pollard, et al. Defendant cites six patents and one article in support of the contention that the button and hole lock was old — but none dealt with an article at all resembling, or comparable to, an egg carton, whether of molded pulp or plastic. They are: (a) Pollard, 320,814 issued June 23, 1885, on application filed March 27, 1885, for "Car Ticket or Stamp Box.” The article was to be “stamped out or otherwise made at slight cost.” (Col. 2, Is. 43-44). A stud on an outward tensioned section, when the lid is closed, enters “a recess or opening . . . formed into or through the cover . . .” (Col. 2, Is. 43-44). No compartments or tying partitions are shown. (b) Hooper, Br. 406,159 issued February 22, 1934, on application filed May 11, 1933, for “Improvements in Boxes or Cases for Jeweliry or Other Light Articles.” The box is of molded synthetic resin. The bottom has a relatively thin tongue “in which is fixed a pin having a projective head ...” (Col. 2, Is. 78-79) which on closing enters a recess in the top. (c) Vogel 2,483,304 issued September 27, 1949, on application filed December 11,1945, for “Container” for “a cigarette package or the like” (Col. 1, 1. 2) to be made of plastic or other suitable material. A nub or projection in the base engaged a small dimple or recess in the forward wall of the cover part (Col. 4, Is. 73-75). This can be reversed, putting the projection on the cover, and the recess in the flange. (Col. 5, Is. 2-3). (d) Vogel 2,509,462 issued May 30, 1950, on application filed August 15, 1946, for “Spring Hinge”. “. . . a retaining projection 27 formed on the forward wall of flange 20 .” engages “within a retaining recess 28 in the forward wall of the cover part . . .” (Col. 3, Is. 72-75). The claims do not refer to the locking device. (e) DeWitt 2,215,856 issued August 2, 1938, on application filed June 27, 1936, for “Box”. Although not limited thereto, the patent was at least primarily directed to a tackle box of transparent or translucent material (Col. 1, 1. 15) such as celluloid (Col. 1, 1. 39). The specification is far from clear as to the closing mechanisms. While it appears that 13 represents recesses in the cover and projections in the tray, Col. 1, lines 53-55 refer to 13 as “Knobs in the front wall of the base and cover.” (Emphasis supplied). While compartments are shown, there is no hinged top. (f) Hunziker 1,354,042 issued September 28, 1920, on application filed March 8, 1920, for “Cigarette Case”. Hunziker is fully described and analyzed in Walterhoefer, 289 F.Supp. at 558. While the Court pointed out on page 559 of 289 F.Supp. the improbability that Hunziker would be discovered (or chargeable to) one in the molded pulp egg carton field, its conclusion was then even if Hunziker ’042 had been found, it would not be pertinent. The Court is of the opinion that the same reasoning applies to polystyrene egg cartons, and that the following language (289 F.Supp. at 559) is sound today, with respect to egg cartons, whether of molded pulp or polystyrene: “. . . Hunziker had no flap, or hinged flange, on the ‘tray’ portion, a feature indispensable in Cox ’233 and Reifers ’094 for purposes of automated loading and closing; and for safety loading. Opening in Hunziker was accomplished by pushing in the entire bottom or tray section — not pushing in the lug or a flange; and loading was to be from the side, not from above. The Hunziker locking system would be completely (commercially) impracticable in a molded pulp egg carton without serious modifications — e. g., a hinged flange on the ‘tray’ section, which would not only not be suggested by Hunziker, but which would make Hunziker unworkable. “The court has been referred to no authority for the proposition that, and has a presently insuperable difficulty in understanding how, a device which requires a modification making it unworkable suggests such a modification in any field, let alone an unrelated one.” (g) Modem Plastics, April 1946, page 177. “Latching Methods “Whenever a hinge without a spring is used, some method must be devised for keeping the cover in a closed position. Figures 11 and 12 show two methods of accomplishing this. In Fig, 11, an undercut bump is molded on the inside of the cover and a corresponding slot is either molded or ground on the outside of the bottom. When rigid materials are used, assembly must be accomplished with great accuracy. “Another method, shown in Fig. 12, allows for greater variation in the closed location of the top and bottom. In this case, a clip of flexible spring brass is stamped out so that the upper portion has a rounded undercut and the body has a sharp protrusion. A vertical slot is molded in the bottom of the box. The spring clip is then assembled in this slot, and held rigidly in position by the sharp protrusion. An undercut bump is molded in the proper location in the cover so that it will engage with the spring clip. Slight variations in the relative locations of the top and bottom of the box can be compensated for by bending the spring clip either forward or backward.” Note that in both instances the insertion is from the outside in, just as in the pre-Reifers ’094 art. Also, in the Fig. 12 illustration, a “clip of flexible spring brass” is used. If, as Defendant urges, the button and hole lock was so obvious and well-known, the Examiners in the Patent Office should not have allowed any patent based on this lock to issue after Pollard. It is clear that the button and hole lock has many possible applications. Those above cited do not suggest its acceptable application to egg cartons, whether of molded pulp or polystyrene. In none of the instances was the article suitable for an egg carton. In many, there were no compartments or tying partitions. None was intended for automatable filling, or for nesting — both indispensable for a commercially acceptable egg carton. None of these singly, in combination, or together did what Reifers ’094 did— provide an integrally connected egg carton, fully capable of automatable filling ; manual opening and reclosing; and effective with or without contents; and nestable. The “state of the art” at the time of the Reifers ’094 invention was considered in Walterhoefer, 289 F.Supp. 563-568. This Court concluded then that Reifers ’094 was a valid patent for a molded pulp egg carton. A review of Cuno Engineering Corporation v. Automatic Devices Corporation, 314 U.S. 84, 62 S.Ct. 37, 86 L.Ed. 58 (1941); Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corporation, 340 U.S. 147, 71 S.Ct. 127, 95 L.Ed. 162 (1950); Graham v. John Deere Co., 383 U.S. 1, 68 S.Ct. 684, 15 L.Ed.2d 545 (1966); Anderson’s Black Rock, Inc. v. Pavement Salvage Co., Inc., 396 U.S. 57, 90 S.Ct. 305, 24 L.Ed.2d 258 (1969); and National Steel Corporation v. Baltimore & Ohio Railroad, 313 F.Supp. 934 (D.Md. 1970) does not lead to any other or different conclusion today. Three additional facts support the conclusion of validity. (1) Commercial success is admitted. “Unquestionably, the Diamond carton that evolved was a commercial success. Diamond profited handsomely — it sold billions of cartons.” The limited, but sometimes important, effect of commercial success was considered in Walterhoefer, with the standard citations (289 F.Supp. 569-570). (2) Dolco’s advertising contained pictorial representations of an egg carton, emphasizing a lock either identical with, or similar to the appearance of, the Reifers button lock. In the lower left-hand comer of the fourth page of Dolco’s twelve page brochure (Plaintiff’s Exhibit 45) entitled “How to order your own Kool-Pak Cushion Foam Egg Cartons” the following caption appears under a picture showing a button of the Dolco carton protruding through the opening formed in the front wall of the cover: “Revolutionary Easy Lock works perfectly on existing closure equipment to fasten lids firmly in place.” In Dolco’s advertisements (Plaintiff's Exhibit 46, Plaintiff’s Exhibit 47) the claim is made for the lock that: “Patented ‘Easy Lock’ proven fool proof, works perfectly on existing equipment.” (Emphasis added). Continental Packaging Corporation on November 18, 1968, wrote to Dolco (Plaintiff’s Exhibit 59A), referring to Dolco’s “Patented Easy Lock” feature and inquired as to whether or not Dolco was referring to its own patent; to a license under Reifers ’094; or to a “patent applied for” status. On December 27, 1968, Defendant’s counsel replied, quite evasively, (Plaintiff’s Exhibit 59D) : “Upon inquiry, I find that the word ‘Patented’ appeared without intention of threat or warning to the trade but only with intention to illustrate various attributes of the Dolco cartons. To avoid possibilities of confusion or misunderstanding of intent, the working which prompted your inquiry is no longer being used in Dolco advertising.” This Court and this Circuit have frequently recognized the significance of the flattery of imitation. In Otto v. Koppers Co., Inc., 246 F.2d 789, 800 (4 Cir. 1957), Judge Haynsworth stated: “. . . The oft quoted statement of Judge Hough in Kurtz v. Belle Hat Lining Co., 2 Cir., 280 F. 277, 281 is appropriate here: ‘The imitation of a thing patented by a defendant, who denies invention, has often been regarded, perhaps especially in this circuit, as conclusive evidence of what the defendant thinks of the patent and persuasive of what the rest of the world ought to think,’ a principle well recognized in this Circuit. Ackermans v. General Motors Corp., 4 Cir., 202 F.2d 642; Black & Decker Mfg. Co. v. Baltimore Truck Tire Service Corp., 4 Cir., 40 F.2d 910.” See also McKee et al. v. Graton & Knight Co., 87 F.2d 262 (4 Cir. 1937) ; Rohm & Haas Co. v. Roberts Chemicals, Inc., 245 F.2d 693 (4 Cir. 1957). As this Court stated in O. M. I. Corporation of America et al. v. Kelsh Instrument Company, Inc., 173 F.Supp. 445, 457, D.C.Md.; 279 F.2d 579 (4 Cir. 1960): “. . . This Circuit has often emphasized the great weight, on the question of validity, that should be accorded the flattery of imitation; that the presumption of validity is further buttressed when the one atacking validity ‘gives the tribute of its praise to the prior art’ but gives to the patent ‘the tribute of its imitation.’ ” See also Mobil Oil Corporation v. W. R. Grace & Co., 367 F.Supp. 207 (D.Conn. 1973): “. . . The fact that the defendant copied the inventions of the patents in suit rather than the prior art is further evidence of invention.” (3) Plaintiff has licensed the manufacture, use and sale of egg cartons under the Reifers ’094 patent to the following substantial manufacturers of egg cartons: Molded Container Corporation, February 27, 1964, Plaintiff’s Exhibit 161; Keyes Film Company, January 1, 1966, Plaintiff’s Exhibit 166; Packaging Corporation of America, January 1, 1969, Plaintiff’s Exhibit 167; and Container Corporation of America, April 1, 1969, Plaintiff’s Exhibit 168. As will be further mentioned, the Packaging Corporation of America license covers “molded egg cartons” and “the substitution of materials such as molded plastic, including but not limited to molded foam plastic, for molded pulp . . .” (Paragraph 1(a)). The Container Corporation of America license provides that “Egg cartons licensed hereunder shall include those made of molded foam plastic and molded pulp.” (Paragraph 1(a)). Container Corporation of America is actually engaged in the manufacture of molded foam plastic egg cartons under its license agreement. The acceptance by the trade of licenses in this volume “is not without significance.” American Precast Corp. v. Maurice Concrete Products Co., 360 F.Supp. 859, 863 (D.Mass.1973); Columbia Broadcasting System v. Sylvania Electric Products Co., 415 F.2d 719, 728, (1 Cir. 1969), cert. den. 396 U.S. 1061, 90 S.Ct. 755, 24 L.Ed.2d 755 (1970). Having determined that Walterhoefer was correctly decided and that Reifers ’094 was and is a valid patent for a novel molded pulp egg carton, nestable, capable of fully automatable filling and closing, and of manual opening and re-closing, whether full, partially filled, or empty, there still remain the questions as to whether or not (1) Reifers ’094 is broad enough to cover polystyrene egg cartons; if so (2) is the accused carton an infringement; and if so (3) is plaintiff for any reason barred from recovering for such infringement? 1. Is Claim 1 Of Reifers ’09k Broad Enough To Cover The Accused Device? It is importantly to be noted that the real question is not whether polystyrene is the equivalent of molded pulp, but whether Claim 1 of Reifers ’094 is broad enough to cover the accused device —a polystyrene thermoformed egg carton. Plaintiff does not contend that all thermoformed polystyrene egg cartons infringe (see, for example, the Haveg carton, Plaintiff’s Reply Brief on Infringement, p. 31; Plaintiff’s Exhibit 150). Defendant claims that ’094 does not cover the accused device on such a number of grounds that it is somewhat difficult not summarily to say “methinks thou dost protest too much.” These include (a) File Wrapper Estoppel; (b) Preamble limitation; (c) Dedication; (d) Failure to Apply for Reissue; (e) Statement of Reifers’ Attorney in prosecution. (a) File Wrapper Estoppel. Defendant vigorously, and repeatedly, argues that file wrapper estoppel applies to any attempt to assert that the claims of ’094 cover polystyrene egg cartons. However, a review of the file wrappers shows that this is not one of the classic cases in which an application is amended and narrowed to get the Examiner’s approval, and then after the issuance of the patent, it is sought to apply the broader, but withdrawn, scope. First, the Examiner never did accept the claim (Claim 1) in suit. Secondly, the Board of Appeals did not allow the claim because of, or based upon, any narrowing of the claim by amendment. Third, polystyrene is no where mentioned in the entire file. Since Defendant relies, although without justification, upon file wrapper estoppel, an unusually detailed review of the file history is justified, if not required. (1) The original application included fourteen claims directed to a molded pulp carton, and four claims directed to a lock construction per se. All were rejected as unpatentable over Koppelman 2,093,280. Minor amendments were filed to the pending claims, and four new claims were added, directed to a “one-piece molded pulp carton.” Manufacturing advantages were claimed, and it was stated: “. . .To provide an improved ear-ton construction which will lock itself closed is but a slight contribution to the art, indeed, if that carton cannot be successfully made on any existing type of pulp molding equipment.” A supplemental amendment was filed, cancelling all claims then on file, adding six new claims, all directed to a molded pulp carton; and additions were made to the specification. Before any office action was taken, a second application was filed and the first application was abandoned. This second application included a specification different from the original one, and twelve claims directed to a “molded pulp egg carton.” All claims were rejected on Cox 2,529,140, Koppelman 2,093,280, and Bergstein 2,474,391. An amendment was filed, cancelling ten of the original twelve claims, and added five new ones. Two of these were directed to a “molded pulp carton” but three had no limitation as to material. All claims were rejected on Koppelman and Cox. The Examiner did indicate, however, that Claim 17, one of the claims with no limitation as to material, would probably be allowable if it were amended to specify certain details as to frustro-conieal surfaces of certain flanges. An amendment (Claim 18) was filed, but the suggestion of the Examiner was not specifically adopted. (2) By amendment, one of the non-molded pulp claims was cancelled, and three new claims were filed not limited to molded pulp. All claims were rejected as unpatentable over Koppelman in view of Cox. The second application was abandoned in favor of a third. Its specification was substantially similar to that of the second. It contained eleven claims, of which the first six were not limited to molded pulp. All claims were rejected on Shellman Australian Patent No. 164,896 and Koppelman 2,093,280 in view of Schilling 2,600,130. Various amendments were made, in the course of which Plaintiff sought to distinguish Koppelman on the ground that it required subsequent cutting or punching. On further rejection of all claims they were cancelled in favor of four new ones. These again were rejected on Koppelman, Cox and Schilling; and two new ones were filed, claiming “a nestable molded pulp egg carton made of relatively flexible molded pulp.” These were disallowed, and an appeal was taken. In its appeal brief, Plaintiff stated that the “invention relates to molded pulp egg cartons capable of being mass produced by the suction pulp molding process.” It was agreed that Koppelman and Schilling could not be molded. The Board of Appeals referred to the claimed subject matter as relating “to a molded pulp egg carton.” (3) This is not a case in which, in order to get a claim allowed, an applicant amends his claim to meet the Examiner’s objection, after which the claim is allowed. Hence cases such as Exhibit Supply Co. v. Ace Corp., 315 U.S. 126, 136, 62 S.Ct. 513, 86 L.Ed. 736 (1942); I. T. S. Co. v. Essex Co., 272 U.S. 429, 443, 47 S.Ct. 136, 71 L.Ed. 335; Baker-Cammock Hosiery Mills v. Davis Co., 181 F.2d 550, 563 (4 Cir. 1950); Carter Products, Inc. v. Colgate & Palmolive Company, 164 F.Supp. 503, 520 (D.Md.1958), aff’d. 269 F.2d 299 (4 Cir. 1959); Doughnut Mach. Corporation v. Joe-Lowe Corporation, 67 F.2d 135 (4 Cir. 1933); International Latex Corp. v. Warner Bros. Co., 276 F.2d 557 (2 Cir. 1960); Dow Corning Corporation v. Chertkof, 243 F.Supp. 947 (D.Md.1965); Long Manufacturing Co. v. Holliday, 246 F.2d 95 (4 Cir. 1957); and Parke, Davis & Co. v. American Cyanimid Co., 207 F.2d 571 (6 Cir. 1953), are not in point. In the instant case the Examiner consistently refused to allow any claim, whether or not incorporating the words “molded pulp” on the ground of lack of invention over the prior art, all of which involved molded pulp; and in only one instance (where no specification of material appeared) did he indicate how his objection could probably be met by amendment. The prosecution of the patent does not involve this usual aspect of file wrapper estoppel. (b) Preamble Limitation. Defendant contends that the first twelve (really thirteen) words of Claim 1: “In an integral and nestable egg carton made of relatively flexible molded pulp” and the language, appearing at about the middle of Claim 1 “said molded pulp carton being integrally formed”, constitute a “preamble limitation”, precluding polystyrene being covered by Claim 1. In part this would appear to be another facet of file wrapper estoppel. It is primarily discussed by Defendant, however, in connection with infringement. Although all cases cited by Defendant and Plaintiff will be mentioned, probably the most thorough discussion of the principles involved is found in Kropa v. Robie, 187 F.2d 150, 38 CCPA 858 (1951) when the Court stated: “Is the phrase ‘An abrasive article’ a limitation upon what follows in the counts in issue? This court has often had before it the Jepson problem (243 O.G. 525 — 1917) — whether the preamble to claims in ex parte cases or to the counts in interference cases should be considered as limitations in the claims or counts. Of the thirty-seven cases of this court we have reviewed with respect to this problem it appears that the preamble has been denied the effect of a limitation where the claim or count was drawn to a structure and the portion of the claim following the preamble was a self-contained description of the structure not depending for completeness upon the introductory clause; or where the claim or count was drawn to a product and the introductory clause merely recited a property inherent in the old composition defined by the remaining part of the claim. In those cases, the claim or count apart from the introductory clause completely defined the subject matter, and the preamble merely stated a purpose or intended use of that subject matter.” ****** “. . . On the other hand, in those ex parte and interference cases where the preamble to the claim or count was expressly or by necessary implication given the effect of a limitation, the introductory phrase was deemed essential to point out the invention defined by the claim or count. In the latter class of eases, the preamble was considered necessary to give life, meaning, and vitality to the claims or counts.” (Emphasis supplied). Even more succinctly, the Fourth Circuit stated in Marston v. J. C. Penney Co., 353 F.2d 976, 986 (4 Cir. 1965): “If the preamble merely states a purpose or intended use and the remainder of the claim completely defines the invention independent of the preamble, it is not a limitation on the claims. On the other hand, if the claim cannot be read independently of the preamble and the preamble must be read to give meaning to the claim or is essential to point out the invention, it constitutes a limitation upon the claim.” The general rule, and its exception, were recognized in Stradar v. Watson, 100 U.S.App.D.C. 289, 244 F.2d 737, 741 (1957), where each claim contained not only the same preamble, but the same concluding limiting language. In Deutsch et al. v. Ball, 77 F.2d 930 (CCPA 1925) the court held that in interference proceedings the senior party was entitled to prevail over the junior party, whose claim was identical with that of the senior party except for the insertion in the claim of the use to which the junior party sought to apply his invention. On the other hand, the court in Application of DeNapoli, 302 F.2d 768, 49 CCPA 1056 (1962) held that the limitation in the preamble by the words “In a phonographic transcribing machine” cooperated with the rest of the structure in such a way as to avoid the prior art which corresponded to all of the structure, except for the preamble, but in a different environment. It might be noted that neither Reifers’ Data of Invention (Plaintiff’s Exhibit 132) nor his more detailed write-up of his invention (Defendant’s Exhibit 61) makes any reference to the material from which the patented article was to be made. On cross-examination Reifers testified that he was not told to make his carton of molded wood pulp; that the material was not discussed. This Court believes its summary to be an adequate and accurate summary of Reifers’ attitude with respect to material: “Whether he [Reifers] should have foreseen what was going' to happen or whether he shouldn’t, is something that is going to be argued and I am going to have to try to determine it significance wise. He has made a very forceful approach to T wasn’t concerned about material. I was concerned about a concept of a lock on an egg carton . . .’ — ‘It seemed to me that it didn’t make any particular difference what the material was. I was working, everybody was working with either chipboards or molded fiber at that time and that, therefore, it seemed to me that to say how it should be done on egg cartons of this kind, was all I had to do.” The Court finds no basis for the exclusion of polystyrene from the scope of Claim 1 on the ground of Preamble Limitation. (c) Dedication. Defendant’s argument here overlaps the defense of file wrapper estoppel. In addition, Defendant argues that there was dedication, evidenced by: (i) Claim 1, for a carton made of relatively flexible molded pulp. The file history has been adequately reviewed herein. (ii) A letter (Defendant’s Exhibit 52) of May 17, 1951, from Carl Flocks, then and now patent counsel, that: “What will become the Reifers patent claim 1 has the following mandatory features: “(a) A molded pulp carton having an integral cellular tray . . . ” Plaintiff adequately replies that this communication was directed to the applicability of forthcoming Claim 1 to a molded pulp egg carton made according to Lambert Patent No. 2,978,162 which had issued shortly before. Since the carton in fact constructed under what became Reifers ’094 was also a molded pulp egg carton, it would have been irrelevant to go beyond the similar features of the two cartons. (iii) The statement by Plaintiff’s counsel on November 16,1958, in General Packaging Corporation (The Diamond Match Company, assignee) v. Atlas Tack Corp., In the United States District Court for the Northern District of New York, Civil Action No. 5126, that “The words ‘molded carton’ refer to a carton molded from a slurry of paper pulp.” This was in response to a demand for a “bill of particulars” as to why the accused carton was claimed to infringe the Sherman Tab-Lock Patent No. 2,587,909 (Plaintiff’s Exhibit 71), in which the various clauses of Claim 1 of 'Sherman were related to the accused carton. That carton was also molded from a slurry of paper pulp. That the response was intended only to show that identical elements were found in both articles, is clear by the second sentence: “The words ‘a molded carton’ refer to a carton molded from a slurry of paper pulp. Defendant’s cartons, Interrogatory Exhibits A and B, are such molded cartons . . . ” This response related to a patent other than Reifers ’094; but both the Sherman and the accused devices were molded pulp. It was therefore necessary, on the infringement issues, to point out only the exact reading of Sherman on the accused device. It was not necessary to rely upon the doctrine of equivalents, and the failure to do so would not have been, even as to Reifers, a waiver or an estoppel. (d) Failure To Apply For Reissue. Defendant strenuously contends that the failure of Plaintiff to apply for reissue, apparently to claim for polystyrene cartons, is an abandonment of the right now to assert that Claim 1 of ’094 covers (any) polystyrene egg carton. Section 251 of United States Code Title 35, reads in pertinent part: “Whenever any patent is, through error without any deceptive intention, deemed wholly or partly inoperative or invalid, by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent, the Commissioner shall, on the surrender of such patent and the payment of the fee required by law, reissue the patent for the invention disclosed in the original patent, and in accordance with a new and amended application, for the unexpired part of the term of the original patent. No new matter shall be introduced into the application for reissue.” * -X- * * * X- “No reissued patent shall be granted enlarging the scope of the claims of the original patent unless applied for within two years from the grant of the original patent.” Defendant contends that: “. . . The evidence in this case clearly established that prior to the expiration of the time within which Reifers could have applied for reissue in June 1963, there were so many indications that plastic cartons were on the horizon that it is impossible to believe that Reifers and the Plaintiff didn’t know of them.” Although efforts toward the development of polystyrene that might, among other things, be useful for the manufacture of egg cartons had been carried on before 1963, the evidence would seem to establish that while some effort toward commercial production occurred in 1965, the first real commercial production of egg cartons from Dow polystyrene foam was in 1968. Five years, or even two years, would seem to a rather far horizon to require Reifers to see and appreciate. Moreover, if Defendant should prove that in 1963 plastic was known as the equivalent of molded pulp, it would be covered by Claim 1 without amendment. “. . . Mere formal alterations in a combination in letters patent, however, are no defense to the charge of infringement, and the withdrawal of one ingredient from the same and the substitution of another which was well known at the date of the patent as a proper substitute for the one withdrawn, is a mere formal alteration of the combination if the ingredient substituted performs substantially the same function as the one withdrawn.” Seymour v. Osborne, 78 U.S. (11 Wall) 516, 555-556, 20 L.Ed. 33 (1871); Laser Alignment, Inc. v. Woodruff & Sons, Inc., 491 F.2d 866 (7 Cir. 1974). If polystyrene in 1963 was well known as the equivalent of molded pulp, there was no need to claim it. If it was not, then it could not properly be claimed by reissue, but would require a separate application and a different patent. As the Court, perhaps somewhat inelegantly, stated in the course of the trial, you do not negative something that is going to happen in the future, or put in the patent that you claim “anything else the Lord may give us the insight to develop which can be used.” This case was filed May 26, 1969. Defendant certainly knew that an important question would be the availability of polystyrene for egg cartons in the period 1952-1963, and whether during that period any egg cartons, with or without the Reifers lock, had been made. The Plaintiff knew this also, and directed Interrogatory 93 to Defendant, as follows: “93. Was foam polystyrene sheeting, suitable for the forming of thermoformed egg cartons, commercially available in 1961?” The original answer, filed about January 5, 1971, reads as follows: “The quality of foam polystyrene sheeting, its availability, or its suitability for, the forming of thermoformed egg cartons as of February 1952 or 1961 is unknown to the Defendant. Defendant believes that foam polystyrene sheeting was unknown as of February 1952, or, if known, was no more than a laboratory curiosity. The same answer applies to 1961.” (Emphasis added). The trial began on March 1, 1971, and after hearing opening statements the Court and parties visited Palmer (Plaintiff’s plant) and Lawrenceville (Dolco’s plant). Upon return and before the taking of any testimony the Court indicated the probable significance of the availability of foam polystyrene, and particularly if “practical cartons were being made at that time.” So alerted and alarmed, Defendant filed an amended answer on January 27, 1971, stating: “To avoid any possibility that Plaintiff may be misled by Defendant’s previously filed response to Plaintiff’s interrogatory No. 93, Defendant hereby informs, and notifies Plaintiff of facts which have come to the attention of Defendant’s counsel subsequent to the time Defendant’s original answer to interrogatory No. 93 was filed and upon which Defendant will rely at trial.” The amended answer lists some thirty-five publications or patents and two court decisions. Defendant contends that these describe usage of foam polystyrene sheet materials produced by the extrusion process in the manufacture of various types of products including containers “similar to egg cartons, but not specifically including egg cartons.” Defendant refers to abortive efforts by Mead Corporation beginning in 1961 to make egg cartons from flexible styrene foam; and the work of Container Corporation of America on foam sheet material from 1962, and production for sale in 1965. However, as previously noted, on April 1, 1969, after the Walterhoefer decision, Container Corporation of America took a license for egg cartons “made of molded foam plastic and molded pulp” (Plaintiff’s Exhibit 168); and is actually manufacturing molded foam plastic egg cartons under that license. From the foregoing, the Court holds that Plaintiff is not barred by its failure to apply for a reissue patent, from claiming that Claim 1 of Reifers '094 reads on the accused carton. (e) Statement of Reifers’ Attorney In Prosecution. In the course of the prosecution of the Reifers patent, his attorney said, in part : “. . .To provide an improved carton construction which will lock itself closed is but a slight contribution to the art, indeed, if that carton cannot be made on any existing type of pulp molding equipment.” First, this argument was made in relation to Claim 2 of Reifers ’094, relating to locating the locking lugs on the top margin of the flap and the locking apertures at the junction of the top cover panel with the cover front wall. That claim is not involved in this litigation. Secondly, paperboard and molded pulp were the egg cartons then in use. Reifers was working with pulp molding equipment, and if the patented carton could not be molded, but only, say, made by hand, it would be commercially valueless. Thirdly, in any type of molding equipment whether for wood pulp or foam polystyrene, the article to be molded must have such configuration that it may be removed from the mold without undue effort or destruction. None of the foregoing singly, or in totality, is or are enough to exclude polystyrene from the coverage of Claim 1 of Reifers ’094. As pointed out under the next topic, Infringement, polystyrene performs the same function as molded pulp, in the same way, to produce the same results — in other words, is an equivalent. Anticipatorily, however, the following factors should be considered: 1. As pointed out above, the trade considers that Reifers ’094 covers polystyrene (when of similar configuration) by accepting licenses under Reifers ’094 for molded pulp and polystyrene: Packaging Corporation of America, January 1, 1969, Plaintiff’s Exhibit 167; and Container Corporation of America, April 1, 1969, Plaintiff’s Exhibit 168. Secondly, the interchangeability of molded pulp and polystyrene is recognized in the very patent under which Dolco manufactures the accused cartons — Snow 3,398,875. The Abstract of the Disclosure refers to egg cartons generally, without reference to material. The patent itself states: “Egg cartons are made to nest and have their bottoms and tops of approximately the same depth. When molded foam pulp or a plastic of about the same stiffness as pulp . . . ” The specifications contain no reference to material. The claims each refer to a “molded carton” without further description of its material. Thirdly, in Snow Patent No. 3,603,-499, issued September 7, 1971, Snow states (Col. 1, Is. 64-66): “The egg carton shown in the drawing is molded from foam pulp or a suitable plastic, polystyrene foam being a preferred example . . .” Fourthly, the Patent Office classifies Snow 3,398,875, Snow 3,603,499, Reifers ’094, and the Commisso (Mobil) Patent No. 3,337,110 for a carton from paper pulp or foam plastic in Class 229 (Paper Recepticles) subclass 2.5 (Pressed). Again, pulp is the preferred material, with polystyrene as a substitute equivalent. 2. Infringement — Equivalance — Law. Plaintiff does not contend that Reifers ’094 covers every plastic egg carton. It does contend that the accused carton, although made of foamed polystyrene is the equivalent of the carton covered by Claim 1 of Reifers ’094. With this the Court agrees, on the basis of the grounds hereinafter considered. These grounds include the similarity if not identity of the configurations (geometry); the fact that the accused carton was designed with knowledge of Reifers ’094; that Dolco never did consider making a carton with a lock different from Reifers’; Doleo’s advertising of the Reifers lock as revolutionary and foolproof; the interchangeability of the cartons; their similarity of action when loaded with eggs; and the absence of any significant difference between the two. (a) Similarity Of Configuration (geometry) . A visual examination of the Reifers carton and the accused carton will show their striking physical and functional similarity, and particularly the similarity of the cover with the female receptacles and holes, and the flap on the tray, with the male members or lugs or buttons, the locking being from the inside out. Further comparison would seem to be unnecessary in view of Defendant’s concession: “Purely for the purposes of argument it may be conceded that the contours and dimensions (persistently referred to by plaintiff as the ‘geometry’ of the carton) and the respective modes of operation of the two cartons are quite similar. But even if they were absolutely identical, this fact would not provide an excuse for the application of the doctrine of equivalents . . . ” For this contention Defendant relies upon International Latex Corp. v. Warner Bros. Co., 276 F.2d 557 (2 Cir. 1960); Parke, Davis & Co. v. American Cyanamid Co., 207 F.2d 571 (6 Cir. 1953); and Slayter & Co. v. Stebbins-Anderson Co., 117 F.2d 848 (4 Cir. 1941). None of these supports Defendant’s position. In International Latex, plaintiff’s patent was for a latex girdle “the external surfaces . . . being smooth and the inside surfaces thereof being of a slightly roughened matted character.” This language was the result of an arduous experience in the Patent Office, and was expressly required to overcome cited prior art. The court held that this was not infringed by a latex girdle in which flocking had been inserted, instead of roughening the latex itself. In Parke, Davis, plaintiff sued defendant for alleged infringement of its patent for an antianemia vitamin product. The claims called for an acid “derived by autolysis of mammalian liver tissue . . .” In its application plaintiff had endeavored to obtain claims not limited to this specific derivation, e. g. “obtainable from” or “a constitment of” or “derivable from mammalian liver tissue.” The Patent Office required the use of “derived”. Plaintiff yielded, and the claims so amended were allowed. The court held that under these circumstances defendant’s product which was a “chemical compound identical with that described in the patent but . . . is made from different starting materials and by an entirely different process from the product of” plaintiff, and “not derived from mammalian liver tissue nor from any animal product” was not infringing. In Slayter & Co., the patentee’s preferred blown wall insulation was com-minuted corncobs and plaster of paris. The court held that although the patent was void for lack of invention, even if valid it would not have been infringed by the substitution of old for new. (b) The Accused Carton Was Designed With Knowledge of Reifers '094. That Snow, the patentee in Patent No. 3,398,875 under which the accused carton is licensed to and made by Dolco, was familiar with Reifers ’094 before Snow designed his carton is clear from the evidence. (Transcript p. 1982). “Q. [By Mr. Brinkman] Mr. Snow, I believe in a question asked by the Court, you testified that before the design of your carton was finished, you became familiar with the patents in the egg carton field, is that correct? “A. [Mr. Snow] Yes, I did. “Q. [By Mr. Brinkman] I will show you herewith a copy of a patent which is the patent in suit, Reifers patent 2,990,094, Plaintiff’s Exhibit 19, and I will ask if this was among the patents that were considered at that time. “A. [Mr. Snow] Yes, it was.” This makes it difficult to understand how Defendant could seriously argue that Hoeltke v. C. M. Kemp Mfg. Co., 80 F.2d 912 (4 Cir. 1935) is “readily distinguishable, one outstanding difference being that in Hoeltke the patented device had been submitted to the defendant and it designed its alleged avoidance with that device before it.” That Dolco recognized the risk involved in manufacturing and selling the accused carton, is seen by the fact that “Dolco was advised, as Porteo had been, that its cartons do not infringe the Reifers patent.” (c) Dolco Never Considered Mak