Full opinion text
AUSTIN, District Judge. The Parties. 1. Plaintiff, Carl Schnell (referred to hereafter as “Schnell”), is a citizen of Germany, residing at Winterbach near Schorndorf, Germany. Plaintiff, The Griffith Laboratories, Inc. (referred to hereafter as “Griffith”), is an Illinois corporation, having its principal office and place of business in the City of Chicago, Illinois. Defendant, The AllbrightNell Company (referred to hereafter as “Allbright-Nell” or “Anco”), is a corporation of the State of Illinois, having its principal office and place of business in the City of Chicago, Illinois. De-' fendant, Peter Eckrich and Sons, Inc. (referred to hereafter as “Eckrich”), is an Indiana corporation having its principal office and place of business in the City of Fort Wayne, Indiana. PX-87. Ownership of Patents in Suit. 2. Plaintiffs are and since the respective dates of issuance have continuously been joint owners of United States Letters Patents 2,840,318, 2,906,310, 2,934,120, 2,934,121, and 3,044,514, and United States Letters Reissue Patents 24,683 and 24,764, and all rights of recovery for all infringements thereof. All of these patents were duly and legally issued on inventions made by Carl Schnell. With the exception of Reissue Patent 24,683, these patents relate to comminuting machines that emulsify meat products. These machines are widely used by sausage manufacturers to produce new and improved meat products. Reissue Patent 24,683 relates to methods for emulsifying meat products, which methods are also widely used by sausage manufacturers. PX-87. The Actions. 3. Plaintiffs, Schnell and Griffith, brought the following patent infringement actions against defendant, Eckrich, in the United States District Court for the Northern District of Indiana, Fort Wayne Division: C. A. 1128, filed 2/13/59, involving U. S. Letters Patents 2,840,318 and 2,842,177; C. A. 1184, filed 9/30/59, involving U. S. Letters Patent 2,906,310; C. A. 1211, filed 2/8/60, involving U. S. Letters Reissue Patent 24,764 (a reissue of Patent 2,842,177); and C. A. 1229, filed 4/26/60, involving U. S. Letters Patents 2,934,120 and 2,934,121. PX-88, PX-89. 4. On January 14, 1960, defendant, Allbright-Nell, brought a declaratory judgment action against plaintiffs, Schnell and Griffith, in the United States District Court for the Northern District of Illinois, Eastern Division, involving U. S. Letters Reissue Patent 24,683 (a reissue of U. S. Letters Patent 2,836,-825) and U. S. Letters Reissue Patent 24,764 (a reissue of U. S. Letters Patent 2,842,177). This action was identified as Civil Action No. 60-C-62. PX-88, PX-89. 5. On November 21, 1961, plaintiffs brought the above-entitled Civil Action No. 61-C-1979 against defendants alleging infringement of each of U. S. Letters Patents 2,840,318, 2,906,310, 2,934,120 and 2,934,121, and U. S. Letters Reissue Patents 24,683 and 24,764. PX-89. 6. Civil Actions Nos. 60-C-62 and 61-C-1979 were consolidated, after which plaintiffs and defendant, Eckrich, stipulated for the dismissal, without prejudice, of the patent infringement suits in the Northern District of Indiana, referred to in Finding 3, above. This stipulation provides: (a) The dismissal shall not give rise to the defense of estoppel or laches or statute of limitations with respect to the causes of actions set forth in the complaints in Civil Actions Nos. 60-C-62 and 61-C-1979, unless such defenses would have been available without such dismissal; and (b) The dismissal shall not be considered a voluntary dismissal under Rule 41(a) of the Federal Rules of Civil Procedure. PX-89. 7. The original complaint in Civil Action No. 61-C-1979 was revised by an order of this Court, dated July 17, 1962. The revised complaint brought into suit plaintiffs’ U. S. Letters Patent 3,044,-514, issued on July 17, 1962. Claims in Suit. 8. Plaintiffs asserted that defendants, or either of them, infringe the following patents (PX-2), including the claims identified with respect thereto: Patent 2,840,318: Claim 2; Patent 2,906,310: Claims 1-8; Patent 2,934,120: Claims 1 and 2; Patent 2,934,121: Claims 1-24; Re. Patent 24,764: 15; Claims 1-3 and 5- Patent 3,044,514: and 18; and, Claims 1-15, 17 Re. Patent 24,683: Claims 1-16. Sausage Industry. 9. The sausage industry is based on the utilization of the portions of the carcasses of cattle or hogs which cannot be used as steaks or hams or pork chops. This material is known in the industry as trimmings, and is the portion of the carcass that is left over when the prime cuts are removed. Many types of trimmings contain gristle and/or hard meat (e. g., rinds and offal materials) which nonetheless have high protein or nutritional value when suitably cut. Cypser 47, 48, 53, 54; Swanson 90, 91, 94-98, 107-110; PX-7; Turner 147-150, 165; PX-82. 10. Sausage emulsions were produced almost entirely by use of machines like the Silent Cutter, or chopper as it was more often referred to. These machines were large, bulky and relatively slow, and they did not produce the quality of emulsion now available, nor did they permit the use of many nutritious portions of the carcass which could not be adequately subdivided in them. Swanson 80-87; Cypser 47, 48, 53. 11. The Silent Cutter was a standard piece of equipment that was used by commercial sausage kitchens for many years before Schnell discovered a meat comminuting machine. It comprised a doughnut-shaped bowl that turned in a horizontal plane and a cutting zone with a series of vertically rotating blades. The mass of meat in the doughnut-shaped bowl was forced continuously into these vertically acting cutting blades. This reduced the particle size of the meat and fat products and, with the addition of moisture that was added to the mix, made a blend. The Silent Cutter caused a high temperature rise of the meat in a short period of time. This was extremely undesirable because a high temperature rise caused a marked variation in the product which in turn affected the salability of the product. Further this machine required a batch operation. The cutting blades had to be continuously kept in a sharp condition for efficient operation and the knives presented considerable danger to the operator. Swanson 102-104; PX-5; Turner 116-117, 152-154; Cypser 76; PX-4. 12. With the old type of sausage production which depended upon a chopper (e. g., Silent Cutter), the hard portions, while substantially reduced in size, oftentimes were like small particles of gravel and because of this it was necessary to eliminate the use of many types of hard trimmings which had high nutritional value and which would decrease the cost of the sausage. Cypser 53. 13. Colloid mills were also used, to a limited extent, to comminute meat. These, too, produced a high temperature rise of the meat. Further, their tearing action produced an undesirably stringy product. Swanson 86-88. 14. Commercial sausage kitchens used a grinder, followed by a chopper (e. g., Silent Cutter), followed by stuffing means and then treatment in a smoke house. The grinder was used to break down the large pieces of meat product into a size suitable for further blending and cutting in the chopper, where moisture and seasoning were added. Cypser 46; Swanson 82; PX-4; PX-8; DX — 92. 15. This finished emulsion then went to stuffing apparatus which placed it into casings of a size suitable for frankfurters or bologna and from there the meat was further cooked or smoked in the smoke house to produce the finished sausage. Cypser 46; Swanson 82; PX-4; PX-8. SchnelPs Discoveries. 16. Schnell discovered that he could cut rinds and offal materials in his early meat comminuting machines in the raw, uncooked state and still be able to produce a better emulsion than had been previously obtained with these materials in other equipment. DX-271A, pages 14, 30, 31; DX-271B, pages 136,145; DX-271C, page 210. 17. He found that he could emulsify nutritious trimmings, including hard particles, that previously could not be used. However, with some meat products it was necessary to exert pressure upon the meat in the hopper in order to force the meat down to the rotary knives. Turner 151, 152. 18. Later, Mr. Schnell made a further discovery of great consequence. He was the first to discover and teach that when meat ingredients were combined in a hydraulic column and propelled by a rotating knife against a perforate valve plate so that most of the material propelled to the plate would not pass through it but would be diverted back for recutting and remixing, one got an entirely new result. Schnell 1666-70; DX-271A, page 39; DX-271F, pages 500, 501. 19. Schnell was the first to discover and teach that this action of the plate made it possible to get better cutting, better distribution and greater output in spite of the fact that the hydraulic column put a tremendous drag on the motor and required a larger motor which caused more heat: The greatly increased output more than compensated for the extra heat produced by the large motor so that there was a lower temperature rise in the product. Schnell 166-70; DX-271A, page 39; DX-271F, pages 500, 501; Turner 162. 20. The rate of comminution depends upon the toughness of the meat, the fluidity of the mixture and many other factors. But even with the toughest meat, the capacity of Schnell’s sealed emulsifier is almost incredible. Eckrich’s records show many instances of treatment of well over 500 pounds of meat per minute. With conventional high grade sausage emulsions, com-minuting 200 or 300 pounds per minute is now standard with plaintiffs’ and defendants’ emulsifiers. The machine introduced a new problem to the industry, namely, trying to supply the machine with an adequate rate of feed material which became necessary due to the markedly increased rate of comminution. This led to automation of the industry. Turner 162; Swanson 100-102; Cypser 52; PX-92A and C-R; PX-94A-H. 21. The reason why the comminuting of material like meat is so greatly improved with the hydraulic column is theoretical in that one cannot watcn what happens to an individual particle of meat. One can observe only the result in greater capacity, greater load on the motor, improved emulsification and a limited temperature increase. Fishleigh 2790, 2810; Schmidt 3564; Turner 160-162; Swanson 100-102; Cypser 52. 22. With the hydraulic column, the pressure of the atmosphere is employed to maintain continuity of meat material in the emulsifier. The 14.7 pounds per square inch pressure of the atmosphere assures that the movement of one particle away from the knife, after being hit, pulls at least another particle into cutting position. Schoenherr 3848-3850; Turner 442. 23. The hydraulic column is essential for most commercial operations as now practiced. The power requirements are several times greater when the hydraulic column exists, but the feeding of meat is difficult without the hydraulic column. In fact, introducing a few bubbles of air in the entrance of the comminuting chamber will normally stop any feeding of meat or at least slow it down to a point where overheating results. Turner 160-162, 3742-3743; Cypser 71; Schnell 1666-70; DX-271A, page 39; DX-271F, pages 500-501. 24. In developing his emulsifier, Schnell discovered that certain other structures in the emulsifier afforded added advantages in comminuting meat products. Included in such structures are the particular shape of the propelling knife, the circulating surfaces that cooperate with the knife and perforate plate, and obstructing means. DX-271A, pages 18, 19; DX-271B, page 149; DX-271C, pages 225, 233, 234. Schnell’s Discoveries Revolutionized the Sausage Industry. 25. The Schnell emulsifier revolutionized the sausage processing industry and permitted, for the first time, the sausage manufacturers to produce sausage in a continuous manner rather than in their previous batch-wise operations wherein the meat had to be manually conveyed from the grinder to the chopper and from the chopper to the staffer. The Schnell emulsifier enabled sausage manufacturers to feed their emulsion through pipes directly into the pump-type staffer without any handling. Manual handling of the meat was obviated and sanitation was thus improved. Turner 162; Swanson 100-102; Cypser 52; PX-4. 26. In addition, the Schnell emulsifier enabled the sausage manufacturers to produce a better meat product, enabled them to produce this superior product at a lower per pound operating cost and displaced space-consuming and more expensive equipment. More specifically, the Schnell emulsifier: (a) Permits the utilization of highly nutritious animal products not heretofore usable in sausage, thereby lowering the cost of the sausage; (b) Produces a finer and more uniform emulsified product than the meat industry was able to obtain with existing equipment; (c) Produces a more presentable and salable product; that is, a product that looks better to the average customer and a product that is more uniform in taste and consistency; (d) Provides better utilization of equipment already existing in sausage kitchens. Sausage kitchens can now produce more in terms of pounds of product per hour than through their grinder and/or chopper; (e) Provides savings in labor because it turns out more pounds of meat product per hour with the same or fewer man-hours; (f) Provides savings in floor space. The upright model of the emulsifier occupies much less floor space than the chopper, which could be eliminated; and, (g) Reduces the need for the highly skilled personnel that was previously required. Prior to Schnell, chopping of sausage products was a highly skilled operation. The sausage maker who operated the chopper was a highly paid individual who had developed a special skill in knowing when chopping should be stopped. Cypser 46-54, 57, 62; Swanson 90, 94-102, 107-110; Turner 162, 163-174; PX-4; PX-9. Introduction of Emulsifiers in the United States. 27. During the period of from 1956 to the present time, the Schnell machines have been made by Schnell for Griffith and they have been sold in the U. S. by Griffith under the name “Mince Master” machines. These machines substantially correspond with the structures shown in various Schnell patents in suit. Griffith 535; Turner 216-284; DX-271B, pages 102-106; PX-1; PX-10; PX-79; PX-81. 28. After Griffith’s “Mince Master” machines were introduced and first sold in the U. S., Allbright-Nell first made and sold in the U. S. a copy of the “Mince Master” machine. This copy was later identified as the Anco “Emulsitator” machine. R. 654, 690-691; PX-37. 29. Emulsifier such as Griffith’s “Mince Master” machines and AllbrightNell’s Anco “Emulsitator” machines produce a smooth, uniform emulsion which was not obtainable under the old methods or with the old equipment, in addition to being able to emulsify materials which could not be used in the past. Cypser 56, 57, 66, 70; Turner 163-174; PX-9. 30. In the very few years in which the emulsifiers have been available in this country, the commercial sausage industry now relies greatly upon this type of machine. Cyprus 48, 49, 59; Turner 357-359; R. 690; PX-84. 31. Sausage manufacturers have bought “Mince Master” machines and “Emulsitator” machines because their customers would no longer accept the type of product they formerly made. Swanson 92, 99; Cypser 55, 56; Turner 357-359; R. 690; PX-84. 32. In some instances, sausage manufacturers continue to handle their meat products through both the grinder and the chopper, and then through either a Griffith “Mince Master” machine or Anco “Emulsitator” machine. Even with this procedure, they are able to shorten both the grinding and chopping operations and obtain a savings in labor. Swanson 100, 101; Cypser 52; PX-4; PX-9. 33. Important savings are obtained with the use of the Griffith “Mince Master” emulsifiers and Anco “Emulsitator” emulsifiers. Cypser 48-52; Swanson 94-98; PX-7. 34. The use of Griffith “Mince Master” machines at Armour and Company, a company that makes a minimum of 2,000,000 pounds of frankfurters and bologna per week, was an important factor in converting within an eighteen month period a loss of $2,000,000 to a profit of $4,000,000 in the sausage department. Cypser 48, 50, 51. 35. Armour spent three-quarters of a million dollars purchasing “Mince Master” machines and providing necessary installations such as electrical wiring that was not previously available. The “Mince Master” machines were credited with saving Armour one million dollars during this period. Armour also uses Anco “Emulsitator” machines for the same purpose as its “Mince Master” machines. Cypser 51, 52, 55, 56.. 36. The ability to employ nutritious meat products not heretofore usable in sausage emulsion enabled John Morrell and Company, a manufacturer of meat products, to save as much as 40 per pound of sausage. Swanson 94-98; PX-7. History of the “Mince Master” and “Emulsitator” Machines. 37. Schnell used in 1954 a com-minuting machine with a knife that rotated upon a perforate plate. This machine was used for comminuting pork rinds. In the Spring of 1955, Schnell ordered Huth seals for his meat emulsifier and used them in his emulsifiers before September of 1955. He found, before July, 1955, that if he covered the exhaust with his hand, he could obtain a hydraulic column which, however, overloaded the motor but greatly increased output. Since German requirements did not call for larger output and the Huth seals were not satisfactory for general use, Schnell put the matter aside until he obtained rubber Goetz seals (DX-9) commencing in January, 1956. At that time he also received a request for larger motors from Griffith’s representative, Mr. Young. Schnell 1485-88, 1490, 1646-49, 1666-70; DX-271A, pages 14, 30, 31, 36-38; DX-271B, pages 136, 145; DX-271F, pages 500, 501; PX-125 and -125A; PX-126 and -126A; PX-127 and -127A; Furthmuller 1705-07. 38. Mr. Carroll L. Griffith, president of the plaintiff, Griffith Laboratories, first learned of the Schnell emulsifier in January of 1956 from a Griffith salesman, Mr. Young, who was in Germany. Griffith 524, 525. 39. Griffith first ordered a Schnell emulsifier in January of 1956 and it (PX-81) arrived in this country at the end of April of 1956. It was powered with an electric motor that was rated at 25 horsepower on 60 cycle current and turned at 3600 r. p. m. The drive shaft for the knife was not sealed to prevent ingress of air into the machine during operation. Turner 120-22, 146; Griffith 524, 525; R. 674. 40. The first Schnell machine (PX-81) that was received by Griffith was sent to Coronet Packing Company (hereafter referred to as “Coronet”) in Chicago for the purpose of testing and demonstrating the machine. This particular machine will hereafter be referred to as the “Coronet machine.” Turner 154; Griffith 525, 526; R. 674. 41. The Coronet machine (PX-81) was demonstrated by Griffith at Coronet during the National Independent Meat Packer’s Association convention in Chicago during May of 1956. Turner 154, 155; Griffith 525, 526; Swanson 90, 91; R. 674. 42. The Coronet machine (PX-81) did not produce a hydraulic column; however, it did produce an outstanding emulsion compared to anything then available, particularly with respect to materials such as pig skins and offal meat material. Turner 146; Swanson 90; R. 674. 43. A slushy mix of skins and ice was fed into the machine (PX-81) at Coronet during May of 1956. An emulsion was produced that had a consistency resembling ordinary cold cream. Mr. Swanson, then with the John Morrell Company, described the skins as having been made “ * * * into smooth, creamy emulsion that heretofore hadn’t been possible to do.” Turner 148-50; Swanson 91. 44. When a bologna or frankfurter mix was fed into this Schnell machine (PX-81), the material had to be pushed down through the hopper to the knife and there was a considerable temperature rise, although the emulsion had a very fine texture. Turner 151, 152. 45. While this Schnell machine (PX-81) was at Coronet, it was discovered by Griffith that the motor was overloaded. Turner 155. 46. During May of 1956, Griffith requested from Schnell an emulsifier having greater horsepower. Schnell confirmed this order the same month. Long before this time, Schnell had used a seal about the drive shaft of his high speed meat emulsifiers. Turner 155-156; Schnell 1484; Bihler 1461, 1469, 1470, 1546; Furthmuller 1722; PX-144 and -144A. 47. In September of 1956 Griffith received from Schnell a “Mince Master” machine with a more powerful motor and a seal. It was sent by Griffith to Saratoga Meat Products Company (hereafter referred to as “Saratoga”) in Chicago for test and demonstration purposes. Ammeter readings showed that the machine was operating at between 75-80 horsepower, although it was previously thought by Griffith that a 35 horsepower motor would be adequate. Turner 154, 156-160; Griffith 529; R. 674. 48. During the American Meat Institute convention that was held in Chicago in September of 1956, Griffith displayed the “Mince Master” emulsifier and demonstrated this sealed machine at Sara-toga. Turner 157; R. 674. 49. A “Cutfix” meat emulsifier of Robert Friess K. G. (hereafter referred to as “Friess”), of Germany, was shown for the first time in this country at that convention. It was a copy of a Schnell emulsifier. Griffith 526, 527; DX-271F, page 432; PX-65; PX-67; PX-80. 50. Allbright-Nell, a manufacturer of equipment used by the meat industry, saw the “Mince Master” emulsifier during the American Meat Institute convention in the Fall of 1956. R. 570. 51. About September, 1956, Mr. Carroll L. Griffith, president of Griffith, received a telephone call from Mr. Norman Allbright, president of Allbright-Nell. Mr. Allbright asked if it were possible for Allbright-Nell to enter into an arrangement whereby Schnell’s “Mince Master” machine might be built in the Allbright-Nell plant. Mr. Griffith explained that this was not possible because Griffith Laboratories was SchnelTs U. S. agent and that Schnell had manufacturing facilities in Germany and wanted to build the emulsifiers there. Griffith 529, 530; R. 565. 52. Allbright-Nell sought and obtained from Friess a “Cutfix” meat comminuting emulsifier in January of 1957. This machine was a copy of a Schnell emulsifier. DX-271F, page 432; R. 190, 566, 674, 675; PX-65; PX-67; PX-78; PX-80; Photograph A of PX-17. 53. In January of 1957, AllbrightNell started to duplicate the “Cutfix” machine. Allbright-Nell made castings from it and built an Americanized version (PX-68, Photograph B of PX-17) from these castings. R. 190, 191, 567, 573, 591, 675; PX-65; PX-67; PX-68; Photograph B of PX-17. 54. In describing this copying, Mr. Ralph W. Illsley, chief engineer for All-bright-Nell, testified on page 19 of his deposition: “A. * * * We found that the German fabrication was a problem for the maintenance people and we elected to construct a machine on American standards with American bolts and nuts and screws and things of that kind which a mechanic would replace in the field. The Germans came in with all metric system parts which were absolutely not interchangeable. “Q. You say, ‘We decided this.’ Was that decision one that you made or did somebody else participate in it? “A. It was our management group. “Q. Who was the management group at that time ? “A. Mr. Allbright, Mr. Norman Allbright, Mr. John Allbright. “Q. And yourself? “A. Yes.” R. 591, 592. 55. On page 20 of his deposition, Mr. Illsley added: “Q. Now after this decision to rebuild on American standards was made, did you rebuild? “A. Yes. We took the German machine, part for part, and made new parts similar, but to American standards, and installed them. We also found the German motors to be troublesome and we installed new American Motors.” R. 592, 593. 56. Mr. Carroll L. Griffith warned Mr. Norman Allbright that Griffith Laboratories and Schnell expected to be granted patents in the U. S. and that Schnell was defending his European patents and would likewise defend his U. S. patents. This was confirmed by Mr. Griffith’s letter of March 22, 1957. Griffith 532, 533; PX-40. 57. Representatives of Friess told Allbright-Nell in February of 1957 that Friess wanted Allbright-Nell to be the U. S. “Cutfix” representative. In May of 1957, Mr. Allbright told Friess that in the light of Schnell’s patent position, All-bright-Nell would not enter into an agreement with Friess, but said nothing about Allbright-Nell’s copying of the “Cutfix” machine. R. 565, 675. 58. During May of 1957, Eckrich, a sausage manufacturer, and AllbrightNell orally agreed to cooperate in constructing and testing an emulsifier for meat. R. 676. 59. On June 13, 1957, an Americanized “Cutfix” machine having a larger hopper and larger American motor was sent by Allbright-Nell to Eckrich. This machine was a copy of a Schnell emulsifier. R. 191, 676; PX-68; Photograph B of PX-17. 60. Mr. Nicholas H. Nusbaum of Eckrich said that after seeing the “Mince Master” machine at Saratoga, he liked it and thought that the Americanized version was “almost identical” to the “Mince Master” machine, however, “built to American standards.” This view was shared by others at Eckrich and is readily evident upon comparison of the machines. R. 613; PX-41; PX-73; PX-103. 61. During the Fall of 1957 and thereafter, defendants agreed and conspired together: (a) To modify further the Americanized “Cutfix” machine (PX-68, Photograph B of PX-17) and have the modified machine operate like the “Mince Master” emulsifier that was displayed by Griffith during the American Meat Institute convention in September of 1956; (b) To procure from Griffith a “Mince Master” emulsifier made by Schnell and sold in the U. S. by Griffith; (c) To carry out tests with a “Mince Master” emulsifier at Eckrich; (d) To use the “Mince Master” emulsifier and spare parts for testing and providing a standard for copying purposes and for comparing and finalizing their copies; and, (e) To market an emulsifier resembling the “Mince Master” emulsifier for the general public, regardless of any U. S. patents issued to Schnell or owned by plaintiffs, or either of them. (a) R. 613, 614, 622, 624, 628-34, 636-41, 649, 650; PX-43; PX-44; PX-48; PX-52A; PX-52B;PX-53; PX-92A and C-R; PX-94AH; PX-99; PX-100; PX-101; PX-104; PX-105; PX-107; PX-108; PX-109; PX-110; PX-112; PX-113; PX-117. (b) R. 631, 632, 637, 639; PX-97; PX-98; PX-102; PX-103; PX-104; PX-107; PX-111. (c) R.615, 631, 641, 642; Sondej 3291, 3320; Schmidt 3528-29; PX-103. (d) R. 641-43, 645-50; Sondej 3287-89,3291,3320; Schmidt 3514-15, 3528-29; PX-49; PX-50; PX-51A; PX-51B; PX-53; PX-92A and C-R; PX-94A-H; PX-115; PX-116. (e) R. 616, 637, 645, 659-62; PX-41; PX-45; PX-47; PX-115. 62. During this period, Allbright-Nell was given free access to emulsifiers and parts being built or tested at or by Eckrich. Plaintiffs had no such free access. Sondej 3247, 3287-3291; Schmidt 3511, 3512; R. 616-617; DX-174; DX-175; DX-181A. 63. The oral agreement of May, 1957 between Allbright-Nell and Eckrich was in effect until March 10, 1959, at which time Eckrich and Allbright-Nell entered into a written agreement. The written agreement confirmed previous oral agreements for cooperation in the construction and testing of emulsifiers. AllbrightNell also agreed to defend Eckrich against patent infringement suits by plaintiffs, or either of them. R. 662-665, 676, 677; PX-54. 64. On September 21, 1957, during the American Meat Institute convention at the Palmer House Hotel in Chicago, Mr. Norman Allbright and Mr. Ralph W. Illsley of Allbright-Nell and Mr. Chester W. Schmidt and Mr. Henry Eckrich of Eckrich, met at the Palmer House and, at that time, planned to place an Americanized “Cutfix” machine on its side or in a horizontal position. R. 676, 677. 65. Eckrich ordered from Griffith a sealed “Mince Master” machine during the Summer of 1957 and received one on November 15, 1957. It was demonstrated at Eckrich during December of 1957. It revolutionized Eckrich’s processing procedure. It enabled Eckrich to produce more and better meat emulsions than it ever obtained before. This “Mince Master” machine has been used extensively by Eckrich to emulsify for sale many hundreds of thousands of pounds of meat material, and was used by Eckrich as a standard for AllbrightNell’s and/or Eckrich’s copies of the “Mince Master” machine. R. 621, 622, 631, 632, 637, 639; Schmidt 3523-3529; Sondej 3287-3291; PX-10; PX-92A and C-R; PX-94AH; PX-97; PX-98; PX-102; PX-103; PX-104; PX-107. 66. Eckrich made a horizontal emulsifier for making sausage during October-November of 1957 and it was tested by Eckrich during December of 1957. R. 676, 677; Sondej 3278. 67. Eckrich received a second sealed “Mince Master” emulsifier from Griffith in April of 1958. This machine was designated by Eckrich as a stand-by machine for the first “Mince Master” machine to assure Eckrich that it would always have a “Mince Master” machine available for commercial production. R. 677; Schmidt 3528. 68. Defendants attempted to use a 90° elbow or neck (PX-66, PX-160) between the hopper and knife of their horizontal machine. Since this neck lacked the sloping wall of Schnell Patent 2,840,318, it did not feed material to the knife properly, and defendants were forced to adopt a neck that necessarily included the frusto-conical shape substantially as shown in that patent. The reservoir was connected to the comminuting chamber at the frusto-conical neck portion of the comminuting chamber. R. 192, 598, 599; Turner 258, 310, 311; Sondej 3303-3310, 3311-3317; PX-50, pages 2 and 3; PX-66; PX-83; PX-92A and C-R; PX-94A-H. Description of the “Mince Master” Machines. 69. The “Mince Master” emulsifying machines have a reservoir or supply chamber or portion, a comminuting portion or chamber, and an expeller or discharge chamber or portion with an outlet. Turner 124-127, 131, 236, 257-262, 314-17; PX-1; PX-10; PX-11; PX-14; PX-79; PX-81. 70. The reservoir is connected to the comminuting chamber at the narrow neck portion of that chamber. The com-minuting chamber contains a high speed propelling knife which rotates above and in contact with a flat, stationary, multiperforated valve plate. The knife is powered by a very powerful motor. The plate has a large number of small openings therein and separates the comminuting chamber from the expeller or discharge chamber. A rotary expeller assists in moving comminuted meat material through the openings in the plate and out of the discharge chamber. The “Mince Master” machines are sealed to provide a substantially air-free hydraulic column. Turner 126, 127, 131-133, 179, 259, 269-272,275-278; PX-1; PX-11; PX-14; PX-79; PX-81. 71. The “Mince Master” perforate plates act as a valve in creating substantial back pressure in the comminuting portion. Turner 441; Schoenherr 3810, 3811, 3818, 3882; Fishleigh 2804-2809. 72. The “Mince Master” machines have lugs which are positioned in obstructing and shearing relationship with the rotating knife. The lugs direct circulation of meat material toward the knife and perforate valve plate and relieve or counteract back pressure exerted by the plate. Recirculating surfaces also direct meat material toward the rotating knife and plate and counteract some of the back pressure exerted by the plate but to a lesser degree than the lugs. Turner 177-179, 206-210, 236-239, 258-260,314-317,389-392; PX-1; PX-79; PX-81. 73. The knives used in the “Mince Master” machines are each balanced for rotation and have a hub portion with cutting arms extending outwardly thereof. The perforate valve plate has a large central opening in which the base of the circular hub of the knife rotates. Each of the arms of the knives has an upper or leading cutting edge and a lower or trailing cutting edge. These two cutting edges join each other at the outer extremities of the arms. Each knife arm also has a sloping propelling face extending from the leading edge toward the perforate valve plate. The face of each arm acts as a propeller to urge meat material toward the perforate valve plate. The trailing or lower cutting edges of the arms contact the plate and cut or shear meat thereat. The upper edges and the propelling face of the arms extend centrally of the periphery of the hub at the upper surfaces of the hub. Turner 131-134, 136-144, 184, 273; PX-1; PX-12A; PX-13A; PX-16; PX-81A. 74. The “Mince Master” knives have arms that taper outwardly toward their tips and toward the perforate valve plate to provide hydrodynamic balance. Turner 137, 274; PX-1; PX-12A; PX-13A; PX-16; PX-81A. 75. Each arm of the “Mince Master” knives has a “pressure pocket” as shown at 95 in Fig. 6 of Sehnell’s Patent 2,934,-120 (Fig. 6 is also shown in PX-27). The pocket is of value in taking care of gristle, small tendons and similar materials that are not readily cut and otherwise tend to accumulate as irregularly shaped particles about the size of “BB” shots. The pressure pocket is located at a proper distance above the lower cutting edge to force such tough materials into better cutting engagement with the lower cutting edge and the openings (74 in Fig. 6 of PX-27) of the perforate plate. Turner 137, 138, 143, 144; PX-1; PX-12A; PX-13A; PX-16; PX-81A. 76. The “Mince Master” machines have adjusting structure which enables the user to adjust the relationship of the knife to the perforate plate and the degree of friction between them. Turner 231-233, 262-263, 315-321; PX-1; PX-11; PX-79; PX-81H. 77. In the “Mince Master” machines, meat material is fed into the reservoir to the high speed rotary propelling knife. The material contacting the upper surface of the hub portion of the knife spreads outwardly. The upper cutting edges of the knife cut material in conjunction with lug structure positioned above the knife as well as about the path of rotation of the knife. The knife propels material centrifugally outwardly as well as toward the perforate valve plate, and material that advances to the lower cutting edges of the knife is cut in conjunction with and at the small holes in the perforate valve plate. Material which is brought to the plate but does not go through it is recirculated outwardly and inwardly in a retrograde manner to the restricted entrance of the comminuting portion and is again fed with the central column of new material to the knife and plate. Material is thus presented and represented to the knife and plate and there is repeated mixing of material. The expeller below the plate produces suction on the plate which helps pull material through it and, at the same time, propels material toward and through the discharge opening. Turner 131-134, 143-145, 263-278; Schoenherr 3791, 3798-3836; PX-1; PX-11; PX-12A; PX-13A; PX-79; PX-81. 78. The “Mince Master” machines provide during their operation an air-sealing head of material and a continuously advancing hydraulic column of material. Schoenherr 3848-3850; Turner 442. Description of Anco “Emulsitator” Machines. 79. Allbright-Nell made, used or sold, and Eckrich and Allbright-Nell conspired to make, use or sell, and in certain instances Eckrich used, all in the United States, “Emulsitator” machines. See annotations for Finding 61; PX-37; PX-38; R. 348-355. 80. Defendants, or either of them, Americanized the “Cutfix” machine shown in PX-67 to produce the machine shown in PX-68 and used the same lug structure in the Ft. Worth “Emulsitator” machine shown in PX-18 and Photograph A of PX-28. The four spaced-apart lugs of the Ft. Worth machine are in shearing relationship to the knife. Photograph A of PX-28 is shown below. R. 191, 591-593, 613; PX-41; PX-73; PX-103. 81. The lugs of the Ft. Worth machine extend radially inwardly from the neck or throat portion of the comminuting chamber that is adjacent the reservoir and extend longitudinally toward the perforate valve plate. Turner 323; PX-18. 82. The Ft. Worth machine with an “Emulsitator” high speed, tapered propelling knife (PX-21, Drawing A of PX-26, PX-25) and as shown, in part, in PX-18 and Photograph A of PX-28, was sent by defendants, or either of them, to Armour and Company at Ft. Worth, Texas, at least as early as February 7, 1959. The machine was operated commercially at Ft. Worth but was not purchased by Armour. This machine is shown on page 905, below. Turner 194, 196; Cypser 55. 83. A later Anco “Emulsitator” emulsifier such as exemplified by PX-29 was constructed for use with a high speed, tapered propelling knife (PX-21, Drawing A of PX-26, PX-25) and included the first modification of the arrangement of the lugs. This machine is shown, in part, in Figs. 4, 7 and 8 of Drawing A-l on page 906, below. This same machine was later used with a high speed, non-tapered propelling knife (PX-22, Drawing B of PX-26, PX-25) as shown, in part, in Figs. 4A, 7A and 8A of Drawing A-2 on page 907, below. PX-19; PX-21; PX-22; PX-37; PX-63; R. 325. 84. The first modification of the lugs involved separating that portion of the ring of lugs that was positioned outside the path of rotation of the knife from that portion of the lugs that was positioned in the neck of the comminuting chamber and adjacent the reservoir, and changing the name of the neck lugs to “anti-swirl vanes.” Each of the lugs is in shearing relationship to the tapered and non-tapered “Emulsitator” knives. These separated lugs are shown below in Photographs B1 and B2 of PX-28. Turner 328, 332; Sondej 3283-85. 85. An Anco “Emulsitator” emulsifier such as shown in PX-31 followed that of PX-29. This machine has tapered and non-tapered “Emulsitator” knives and includes a second modification of the lug structure. The machine is shown, in part, with a high speed, tapered propelling knife (PX-21, Drawing A of PX-26, PX-25) and high speed, non-tapered propelling knife (PX-22, Drawing B of PX-26, PX-25) in Drawings B-l and B-2, respectively, on pages 908 and 909, below. PX-20; PX-21; PX-22; PX-31; PX-37; PX-64; R. 324. 86. The second modification of the lugs involved the use of an additional number of lugs around the path of rotation of the knife and the choking-down of the neck leading to the knife so that the entire area between the four spaced-apart neck lugs was filled or replaced with wall structure that provides a continuous annular lug adjacent the reservoir. The lugs around the path of rotation of the knife consist of a continuous lug ring, The continuous lug of the neck and lug ring are in shearing relationship with the tapered and non-tapered knives. This modification is shown below in Photographs Cl and C2 of PX-28. Turner 336-337. 87. If a circle were drawn connecting the free ends of the lugs shown in Photograph B1 of PX-28, the neck becomes choked-down to the circle (i. e., to the size of the opening shown in Photograph Cl). This is shown below wherein the white circle shows the inward extension of the wall that distinguishes the neck of Photograph B1 from that of Cl. 88. The lug structure around and above the tapered and non-tapered knives in the “Emulsitator” machines provides some recirculation in the comminuting chamber. Turner 308; Fishleigh 2812-2813; Schoenherr 3791, 3797-3836. 89. The lugs of the Ft. Worth machine shown in Photograph A of PX-28 and the “Emulsitator” machines shown in Photographs B1 and B2 of PX-28, and the lugs (continuous lug of the choked-down neck and lug ring encircling the path of rotation of the knife) of the “Emulsitator” machines shown in Photographs Cl and C2 of PX-28, each work in substantially the same way and accomplish substantially the same result, although they differ in form and shape and may differ in name. Turner 194-202, 292-313, 325-332, 334-337, 340-343; PX-18; PX-19; PX-20; PX-28; PX-83. 90. Each of the “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2 shown on pages 905 to 909) has a reservoir or supply chamber or portion, a comminuting DRAWING A-1. DRAWING A-2. DRAWING B-l. DRAWING B-2. chamber or portion, and a discharge chamber or portion with an outlet. The reservoir is connected to the comminuting chamber by a narrow neck portion of that chamber. The comminuting chamber contains a propelling knife which rotates at high speeds above and in contact with a flat, stationary, multiperforated valve plate that separates the comminuting chamber from the discharge chamber. The knife is powered by a very powerful motor. A rotary expeller is positioned in the discharge chamber and assists in moving com-minuted meat material through the small openings in the plate and out of the discharge chamber. These machines are sealed during operation to provide a substantially air-free hydraulic column. Turner 130, 194-202, 206-211, 292-304, 307-313,325-332,334-337; Schoenherr 3791, 3797-3836; PX-18; PX-19; PX-20; PX-83; PX-170; PX-171. 91. Each of the “Emulsitator” machines (Ft. Worth machine of PX-18 and Drawings A-l, A-2, B-l and B-2) has lugs which are positioned in obstructing and shearing relationship with the rotating knife. In addition, lugs direct circulation of meat material toward the knife and plate and relieve or counteract back pressure exerted by the perforate valve plate. Recirculating surfaces also direct meat material toward the rotating knife and plate and counteract some of the back pressure exerted by the perforate valve plate but to a lesser degree than the lugs. Turner 200, 205, 206, 310, 323, 328, 336, 477-79; Schoenherr 3791, 3797-3836; Fishleigh 3092, 3093; PX-18; PX-19; PX-20; PX-83; PX-170; PX-171. 92. The tapered and non-tapered high speed “Emulsitator” knives used in these machines are each balanced for rotation and have a hub portion with cutting arms extending outwardly thereof. The perforate valve plates have a large central opening in which the base of the circular hub of the knives rotates. Each of the arms of the knives has an upper or leading cutting edge, and a lower or trailing cutting edge. These two cutting edges join each other at the outer extremity of each of the arms. The arms of the knives also have a sloping propelling face extending from the leading edge toward the perforate valve plate. The face of each arm acts as a propeller to urge meat material toward the perforate valve plate. The trailing or lower cutting edges of the arms of each knife bear on the plate and cut or shear meat thereat. The upper edge and the propelling face of the arms of each knife extend centrally of the periphery of the hub at the upper surface of the hub. Turner 196-199, 202-206, 308, 309, 329, 330, 344-346; R. 602-605; PX-18; PX-21; PX-22; PX-25. ' 93. The “Emulsitator” high speed knife (PX-20, Drawing A of PX-26, PX-25, PX-27), used in the Ft. Worth machine of PX-18 on page 905, above, and “Emulsitator” machines shown in Drawings A-l and B-l on pages 906 and 908, above, have cutting arms that taper outwardly toward their tips and toward the perforate valve plate. Turner 196,197, 344; PX-21; PX-25. 94. The speed of rotation of the arms of the tapered and non-tapered knives increases toward their tips and the force exerted by the arms on meat material also increases with the increase in speed. R. 605. 95. The taper of the tapered “Emulsitator” knife equalizes the work done along the length of the arms so that the outer ends of the arms of the knife do not tend to lift from the perforate plate. The taper thus provides hydrodynamic balance. R. 602-605. 96. The arms of the tapered “Emulsitator” knife each have a forward propelling face that is inclined downwardly and rearwardly from the upper cutting edge. The face of each such arm has a changing and increasing degree of inclination relative to the axis of rotation as the face approaches the path of rotation of the lower cutting edge. This changing and increasing degree of inclination provides a pressure pocket that extends forwardly in rotation of the lower edge and extends along the length of the lower edge. This pressure pocket urges material that is difficult to cut into better cutting engagement with the lower cutting edge and the small holes in the perforate plate. The pressure pocket of the tapered knives of Griffith and defendants is shown in PX-27. Turner 196-199, 308, 309, 329, 330, 340-341,344-346; R. 603; PX-18; PX-19; PX-20; PX-21; PX-25; Drawing A of PX-26; PX-27. 97. The non-tapered “Emulsitator” knife (PX-20, PX-22, Drawing B of PX-26, PX-25) also has a propelling face. Further, it has a pressure pocket that is narrower in the direction of rotation than that of the tapered “Emulsitator” knife. Turner 340-341, 344-346; PX-20; PX-22; PX-25. 98. The following photograph is a copy of PX-25 which compares the tapered and non-tapered knives used in the “Emulsitator” machines. Photograph C shows the pressure pockets of both knives. Turner 344-346. 99. Each of the “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2) has adjusting structure which enables the user to adjust and fix the relationship of the knife (i. e., tapered and non-tapered knives) to the perforate plate and the degree of friction between them. Turner 298-304, 321, 322, 329, 339-343; PX-18; PX-19; PX-20; PX-63; PX-64; Highley 3621. 100. The perforate valve plate of the “Emulsitator” machines has an outer diameter of 248 mm. and a large central opening with a diameter of 120 mm. The knives used in “Emulsitator” machines rotate at about 2,000-2,400 r. p. m. and are driven by 60-100 horsepower motors. Griffith’s “Mince Master” machines that have a perforate valve plate having the same outer and inner diameters are powered by an 85 horsepower motor and have a knife that is rotated at about 2,800-3,600 r. p. m. Turner 179, 180, 210, 237; R. 689, 690; PX-13B; PX-24; PX-55; PX-59; PX-81; PX-83. 101. The defendants operate or sell commercially “Emulsitator” machines with an expeller. They presented no evidence of commercial use or sale of “Emulsitator” machines without the expeller. Ex parte tests were conducted by them for the trial with the less effective and smaller expeller such as shown in DX-154, wherein the expeller is formed by the splines on the shaft after the expeller, which is normally mounted thereon, is removed. Schoenherr 3851-3853; PX-18; PX-19; PX-20; PX-55; PX-56; PX-59; PX-63; PX-83. 102. Meat material emulsified in the “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2) is fed into a reservoir and from there through the neck portion of a com-minuting chamber to the high speed rotary propelling knife. The incoming material strikes the upper surface of the hub portion of the knife and spreads outwardly. The upper cutting edges of the knife coact in cutting material with obstructing means positioned in and associated with the comminuting chamber. The obstructing means include the lugs (spaced-apart lugs in the neck portion of the comminuting chamber and around the path of rotation of the knife of (a) the Ft. Worth machine on page 905, above, and Photograph A of PX-28, (b) Drawings A-l and A-2 on pages 906 and 907, above, and Photographs B1 and B2 of PX-28, and (c) the continuous annular lug of the choked-down neck and lug ring shown in Drawings B-l and B-2 on pages 908 and 909, above, and Photographs Cl and C2 of PX-28). Turner 209-210, 308-311, 329-332; PX-18; PX-19; PX-20; PX-83. 103. Each of the “Emulsitator” knives (tapered and non-tapered) propel material centrifugally outwardly of its axis of rotation as well as toward the perforate valve plate, and material that advances to the lower cutting edge of the knive arms is cut in conjunction with and at the multitude of small openings in the perforate valve plate. Turner 196-199, 308, 309, 329, 330; PX-18; PX-19; PX-20; PX-21; PX-22; PX-83. 104. The “Emulsitator” perforate valve plate exerts a back pressure because it cannot pass material as fast as it is fed to it. This back pressure subjects material to retrograde and axially spiral movement away from the plate while, at the same time, the centrifugal action of the knife causes material to be moved outwardly. The material then moves back and inwardly toward the axis of rotation to the neck portion of the com-minuting chamber and mixes with the incoming material. Meat material is thus presented and re-presented to the high speed propelling knife and perforate valve plate and there is repeated mixing of material in the comminuting chamber. Turner 209-210, 310, 311, 329-332, 441, 442, 477-479; Schoenherr 3848-3850. 105. The lugs and the substantially frusto-conical inwardly and upwardly sloping wall of the neck of the comminuting chamber of each of the “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2) provide recirculation toward the knife and plate. Turner 308-311, 329-332, 388-389; Fishleigh 2744-2747; Schoenherr 3791, 3798-3836; PX-18; PX-19; PX-20; PX-83. 106. The expeller below the “Emulsitator” perforate valve plate produces suction on the perforate plate which helps pull material through the plate and propels a uniformly distributed meat emulsion from the plate to and through the discharge opening. Turner 210, 308, 309, 329-331, 442; Fishleigh 2855, 2856, 3077; Schmidt 3433, 3568-3569; Schoenherr 3848-3850; PX-18; PX-19; PX-20; PX-55; PX-56; PX-59; PX-63. 107. An air-sealing head of meat is positioned above or in advance of the knife in the “Emulsitator” machines and a continuously advancing hydraulic column of meat material extends from at least the entrance of the comminuting chamber to the discharge opening. Schoenherr 3848-3850, 3904; R. 596-597. 108. It makes no functional difference in the operation of the “Emulsitator” machines whether the knife rotates horizontally about its vertical axis as it does in Griffith’s “Mince Master” machines, or rotates vertically about a horizontal axis as is the case with the Anco “Emulsitator” machines. Although the horizontal “Emulsitator” machines provide a lower hopper than the Americanized “Cutfix” machine from which it was copied, this in itself is a mere mechanical expedient and may also be obtained by moving the motor of the Americanized “Cutfix” machine to the side of the machine. Turner 204, 209, 210; Schoenherr 3791, 3797-3836; PX-170; PX-171. 109. The “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2) do the same work in substantially the same way as Griffith’s “Mince Master” machines and accomplish substantially the same results, even though they differ in name, form and shape. Cypser 56, 57, 66, 70; Turner 209, 210; Schoenherr 3791, 3797-3836; PX- , 170; PX-171. Hydraulic Column in “Emulsitator” Machines. 110. The meat material that is emulsified in the “Emulsitator” machines (Ft. Worth machine and Drawings A-l, A-2, B-l and B-2) is in the form of a continuous hydraulic column that has so little air present that the plastic meat material acts according to the law of hydraulics from the entrance of the com-minuting chamber to the point of discharge. To propel this hydraulic column through these machines, a large motor is required and used. Schoenherr 3848-3850, 3904; Schnell 1666-1670; Turner 210, 308, 309, 329-331,442; R. 690; PX-18; PX-19; PX-20; PX-83. 111. The unexpected importance of having this hydraulic column was admitted by the defendants. R. 596-597; PX-46; PX-53; PX-55; PX-56; PX-58; PX-59; PX-61; PX-62. 112. Mr. Ulsley, chief engineer for Allbright-Nell, conceded during his deposition that the hopper of the emulsifier had to be sealed because if any substantial amount of air came in with the meat, the meat would not be cut. He said: “If you get sufficient air in the cutting chamber, the meat does not flow to the knives and therefore it cannot be cut.” R. 596-597. 113. Del Proctor, plant engineer for Eckrich, wrote a letter (PX-46) to Mr. Crawford, vice-president and sales manager of Allbright-Nell, in September of 1957, wherein he acknowledged that Eckrich was unexpectedly surprised to find that by sealing the knife shaft to prevent the ingress of air, there resulted an increase in the rate of emulsified product as well as the load on the motor. On page 2 of this letter, Proctor stated: “On Tuesday, Sept. 24th, Mr. Schmidt, Mr. Nusbaum and myself had a discussion regarding the operation of the emulsifier and tried to establish some reason for the increase in ampere loads at the motor. It was my conviction that the mechanical seal for some unknown reason was causing the increase in amperage to the motor. None of us could justifiably believe that the seal unit itself was causing this increased amperage, however, I submitted the suggestion that, possibly, with the seal unit we were not drawing air up from around the motor shaft and, possibly, creating a vacuum which helped to pull the meat through the super-fine plate. “As a result of this discussion, we decided to take an ohm reading of the motor windings and we discovered that as of this date there has been no breakdown of the insulation to the motor winding and it was further agreed that we would make some test runs with the emulsifier and leave the mechanical seal unit out of the machine to check for the ampere reading. This test was conducted and the machine was run without the seal unit and our ampere readings dropped back to the original 55 to 60 amps., however, it was necessary to more or less hand-feed the emulsifier in that the operator was compelled to constantly push the meat down into the hopper so as to keep meat feeding into the knife and plate section of the machine as you witnessed here at our plant.” 114. Mr. Everett Highley, of the Research and Development Department of Eckrich, wrote a memorandum (PX-53), dated September 5, 1958, to Mr. Schmidt, his supervisor at Eckrich, wherein he stated: “ * * * Mr. Griffith admitted that the seal is one of the secrets of the machine, meaning for the proper operation of it. I definitely agree. In fact, it can’t be stressed too much. If the seal is not working properly, you have short knife life and short plate life which means short machine life. Of course, it doesn’t stop there. A bad seal gives high temperature rise which in turn gives poor color and an excessive amount of air pockets in product.” 115. The “Anco Emulsitator Operating Instructions,” as well as revisions and supplements thereto, emphasize the importance of having defendants’ seal operating to prevent ingress of air during operation. PX-55; PX-56; PX-58; PX-59; PX-61; PX-62. 116. A small amount of air introduced into the “Emulsitator” machines through a one-quarter inch (outer diameter) copper tube stops their operation. Turner 3742-43; Cypser 71. Recirculation in “Emulsitator” Machines. 117. A meat emulsion includes water and oil or grease. It can only be formed with high speed whipping or mixing. This vigorous mixing action occurs in the Griffith “Mince Master” machines and Anco “Emulsitator” machines (Ft. Worth machine and Drawings A — 1, A-2, B-l and B-2) and results from the presentation and re-presentation of meat material to the high speed propelling knife and perforate valve plate (i. e., recirculation). Turner 310, 367-368, 388-392, 408-409, 477-479; Schoenherr 3791, 3797-3836; Miner 3857, 3862-3863; PX-4. 118. Prior to trial, defendants admitted that such recirculation occurs in their “Emulsitator” machines. In their pre-trial brief, for example, defendants stated at page 30: “ * * * The Hilliker machine, like Defendants’, employs a plurality of spaced tines or lugs 43 disposed slightly beyond and in shearing relationship with the distal ends of the knife arms. Large particles of material which might clog the perforations in the plate 39 are spun outwardly by the knife through the spaces 42 between the lugs for recirculation into the column or mass of material being comminuted.” (Emphasis added.) At the trial, however, defendants argued that there is no recirculation in their “Emulsitator” machines when a non-tapered knife is used and only a negligible amount when a tapered knife is used. DX-112; DX-113; DX-115; DX-116. 119. Plaintiffs’ expert, Dr. Schoenherr, amply demonstrated that there must be retrograde circulation and outward and inward movement of material in the “Emulsitator” machines. Dr. Schoenherr is not a professional witness, but an expert in hydraulic design with more than 40 years experience, much of it in charge of propeller design for the United States Navy. His straightforwardness was as impressive as his technical qualifications. Defendants did not even attempt to show how recirculation of material could be avoided. Even Mr. Fishleigh, defendants’ patent expert, admitted this but tried to depreciate the amount of such circulation. Schoenherr 3779-3782, 3791, 3797-3836; Fishleigh 2812, 2813; PX-170; PX-171. 120. The following facts are clearly established by the evidence: (a) The meat above or back of the knife is still swirling when the Anco “Emulsitator” machine is stopped immediately after use. It could not be swirling at this point unless the force of the rotation of the knife had been transmitted backwardly by hydraulic means, as defined by plaintiffs and as admitted by defendants. (b) Not only is there circulation above or in advance of the knife area in defendants’ “Emulsitator” machines, but the uncontradicted testimony is that this circulation is so violent as to bend a quarter inch copper tube when placed at the exit end portion of the substantially frusto-conical part of the neck (point 1 on PX-31). On the other hand, the circulation at the opposite wall portion of the neck (point 2 on PX-31) does not have this degree of violence. (c) Meat is delivered to the perforate valve plate at a speed of the order of 1000 inches per second and passes through at a rate of less than 10 inches per second. The rest of the material must be moved backward and mixed with inflowing material. (d) Even defendants’ crude and secret ex parte tests showed that the green dye which was injected twice per second into the comminuting chamber (during which the meat had moved forward some 5 inches) was evenly distributed throughout the discharged meat. This would not have occurred unless there was retrograde recirculation of meat in the comminuting portion. (e) Plaintiffs’ tests, made under operating conditions in a plant not under their control and in the presence of a Federal Inspector, showed that even with about a teaspoon of carbon black introduced at 6-inch intervals in the hopper, the colored areas of the discharged materials were uniform not only at the points where the carbon black was introduced, but at all points in between so that an extended rope of discharged product had uniform distribution of the carbon black throughout its length. (f) Mr. Turner of Griffith pointed out that pieces of tough meat material that did not pass through the holes in the Aneo “Emulsitator” valve plate were found accumulated above or in advance of the knife after the machine was stopped. These pieces moved rearwardly after reaching the plate, which could only occur as a result of retrograde recirculation. (a) Fishleigh 2792, 2793; Schmidt 3560, 3561. (b) Turner 3739-3742. (c) Schoenherr 3810, 3811, 3818, 3882; Fishleigh 2804, 2808, 2809. (d) Schmidt 3433, 3568-3569; Fishleigh 2855, 2856, 3077. (e) Turner 3743, 3745; Schoenherr 3785, 3787. (f) Turner 486-492, 518, 523. Long-Felt Want and Commercial Success. 121. The Sehnell emulsifier satisfied a long-felt want and met with prompt commercial success. From 1956 to March 1, 1963, Griffith sold in the U. S. about 790 to 795 “Mince Master” emulsifiers, which sales totaled about $3,183,564. During the period of from 1959 to February 28, 1963, Allbright-Nell sold in the TJ. S. about 166 “Emulsitator” emulsifiers. Turner 357-359; R.690; PX-37; PX-84. Infringement of Patent 2,906,310. 122. U. S. Patent 2,906,310 to Sehnell concerns emulsifiers that are sealed during operation to prevent the in