Ferag AG v. Grapha-Holding AG

MEMORANDUM OBERDORFER, District Judge. I. Plaintiff Ferag AG is a family-owned Swiss corporation, with its principal place of business near Zurich; and plaintiff Ferag, Inc. is Ferag AG’s U.S. subsidiary. The two companies are referred to here collectively as “Ferag”. Defendant Grapha-Holding AG is also a family-owned Swiss corporation, with its principal place of business near Zurich — a few kilometers from Ferag. The parties are “two of only a very few companies that manufacture bindery equipment used to assemble or join together pages of brochures and magazines.” Ferag AG v. Graphar-Holding AG, 905 F.Supp. 1, 2 (D.D.C.1995). They compete furiously worldwide. One arena of competition is patent litigation. Each holds numerous patents on its products and elements of them issued by several governments, including the United States, and are vigorously litigating issues about the validity of the patents and infringement. At issue in this case is Grapha’s U.S. Patent No. 4,735,406, referred to by the name of ‘Weber”, the Grapha employee who disclosed and claimed as his invention a rotary drum “gatherer-stitching” machine “for making brochures and the like.” A copy of the Weber patent, issued on April 5,1988, is attached here as Appendix A. The issue is drawn by Ferag’s prayer for a declaratory judgment that the Weber patent is invalid and that no Ferag machine infringes it. Grapha counterclaims that Ferag’s rotary drum “IPEX” machine infringes the Weber patent, although Grapha has never manufactured or sold the rotary drum machine disclosed by the Weber patent. During a 13-day bench trial concluded in May 1996, the parties adduced elaborate proof, illuminated by models and prolific expert testimony. The evidence yields the following: The basic binding machine, a gatherer-stitcher, gathers or accumulates individual folded sheets, known in the trade as “signa — 1240 — tures”, one over the other along their folded edge or spine with the cover being the outermost sheet; places the sheets spine-up over a saddle; and stitches or staples them together along the fold line. The industry standard gatherer-stitcher, including those manufactured and sold by Grapha, is an “in-line” machine, which receives sheets from automated signature feeders and moves the spine-up sheets linearly down a straight gathering chain to the stitcher. In contrast, Grapha’s Weber patent discloses a gatherer-stitcher that would not only move signatures linearly down a chain, but also circularly around a rotary drum. That is, the Weber machine would deposit individual sheets spine-up on carriers which resemble the fins of a paddle-wheel-type rotary drum. Sheet feeders arranged axially along the drum, one downstream from another, would deposit individual sheets on the fins one after the other as the fins rotate past the feeders. At the same time, the individual sheets would move axially along the gathering fins. Each sheet would follow a helical path while moving along the length of the drum. The carriers would advance the sheets to the stitching station, where they would be stapled or stitched together. The stitchers would include two or more staple applicators mounted on a yoke that would be concentric to the drum and would move in a pendulum manner with the drum. The machine disclosed by Grapha’s Weber patent would also differ from Grapha’s own conventional in-line gatherer-stitcher in that the patent claims that the Weber machine would be capable of producing 40,000 copies per hour, whereas the top in-line stitchers, including Grapha’s, are capable of producing only 20,000 copies per hour. Although Gra-pha commands a substantial U.S. share position in the gatherer-stitching market, it has never made or sold a machine covered by any claim of the Weber patent, and in fact, has never constructed a prototype or working model of the machine shown in figure 1 of the Weber patent. See Stip. Facts ¶¶ 38, 40. Grapha’s top product is an in-line gatherer-stitcher which produces a maximum of 20,000 copies per hour. Unlike Grapha, in 1991, Ferag briefly offered for sale a rotary drum machine known as “Print ’91”; and in 1993, Ferag constructed and exhibited a demonstration machine of a rotary drum gatherer-stitcher at its facility in Bristol, Pennsylvania. More important, Ferag presently manufactures and sells an unpatented, high speed, rotary drum gatherer-stitcher, the “IPEX” machine: Ferag’s IPEX machine is capable of binding and stitching at 40,000 copies per hour. There are six IPEX machines operated by Ferag customers in the United States. The IPEX machine consists of a rotary drum, the circumference of which has forty radially protruding fins. A rotary drum’s “fin” is one in-line chain’s “saddle”. These fins extend along the length of the drum. A gripper conveyor delivers folded signatures to the drum. As each signature, held in a gripper at the fold line, moves toward the drum, a star wheel opener separates the two panels of the folded signature. A gripper conveyor and the feeder screw position each signature over an outer edge of one of the fins, guide the signature onto the fin with the signature’s panels straddling the fin, whereupon the gripper conveyor releases the signature. As the drum rotates, the first signatures move circularly for approximately 270 degrees. Only as the signatures reach the last quarter of their rotation around the drum do they move axially by a control slide to the next feeding station, where the process repeats itself. When the signatures reach the stitching station near the end of the drum, a rotatable stapling apparatus, comprised of a earner rotating in a direction opposite to that of the gatherer-stitcher drum and containing ten stapling heads, staples serially, one signature at a time. The stapled signatures then move axially into the exit station. In order to protect its rotary drum gatherer-stitchers from claims of infringement, Ferag seeks a declaratory judgment that Grapha’s Weber patent is invalid and unenforceable, and even if valid, is not infringed by Ferag’s IPEX, Print ’91, and Bristol dem — 1241 — onstration machines.1 Primarily, Ferag contends that the Weber patent is invalid because it claims a gatherer-stitcher machine that was known before Weber described his invention and that the machine Weber claimed to have invented was obvious to those of ordinary skill in the art as it developed prior to June 1985, the date the Weber patent application was first filed in Switzerland. Grapha defends Weber’s patent and counterclaims for a declaratory judgment that the Weber patent is valid and enforceable, and that Ferag infringed the Weber patent by manufacturing, using, offering for sale, and/or selling the unpatented IPEX, Print ’91, and Bristol demonstration machines. II. A. In explanation of the competing claims, the parties generally agreed about the role of gatherer-stitching machines in the print-bindery industry: After the printing press finishes printing the pages of a newspaper or magazine, the bindery machine assembles and stitches them into the finished product. For the last 40 years, the in-line gatherer-stitcher has been the industry standard for assembling magazines. This machine gathers or accumulates individual folded sheets or “signatures” on a linear gathering chain, one over the other along their folded edge or spine with the cover being the outermost sheet. This is known in the trade as accumulating sheets from the “inside-to-outside.” The in-line gatherer-stitcher places the sheets over a saddle, and stitches or staples them together along the fold line. Well-known examples of gatherer-stitched magazines are Time and Newsweek. Currently, the top speed or rate of production for an inline gatherer-stitcher is 20,000 copies per hour. Because the output of a printing press typically outpaces the output of bindery machines, it is often necessary to store unbound pages, a costly and time-consuming step. To save this time and expense, the bindery industry is constantly in search of binding equipment which more nearly matches the speed of the printing press. The industry’s demand for greater bindery speed has been frustrated by the fact that on a conventional in-line gatherer-stitcher, each sheet must be individually transported through the machine; therefore, higher output can be achieved only by increasing the speed of the sheets as they travel along the gathering chain. But speeding the movement of paper linearly can create many difficulties such as air currents, which flutter and tear the sheets. To minimize such difficulties, the speed at which the sheets can be moved linearly is limited, with consequent finite limits on the production rate achievable by an in-line machine. See Weber patent, col. 3, 11. 8-9. Moreover, on in-line chains, the sheets change the direction of their movement roughly ninety degrees when they drop from the feeder to the gathering chain. This abrupt change in direction, if it occurs at high speeds, often causes the pusher on the gathering chain to drive through the sheets and damage them. Id. at col. 1,11. 34-37. Weber’s patent addressed these problems by designing a machine that would change the conventional in-line gatherer-stitcher processing of sheets by putting several straight in-line chains onto a rotary drum, thereby moving paper circularly as well as linearly. Weber claimed that such a rotary drum machine would increase the time to deposit sheets; reduce the axial speed of the sheets thereby eliminating the problems associated with paper traveling at high speeds; reduce the abrupt changes in the direction of the paper; and increase the time for stitching. The evidence is clear and convincing, however, that the idea of putting straight inline carriers on a rotary drum did not originate in 1985 with Weber or with Grapha; Ferag earlier designed and produced a rotary drum binding machine. In 1976, Ferag received a U.S. patent for a rotary drum inserter for handling sheets of paper in newspaper assembly. A copy of — 1242 — this patent, the “Reist” patent, U.S. Patent No. 3,951,399, which issued on April 20,1976, is attached as Appendix B. In contrast to magazines, newspapers are normally assembled from the “outside-to-inside” in a pocket in the shape of an open “V”, that is, the cover or “outside” goes into the pocket first, followed by the inside pages. This process is known as “inserting”; there is no stapling or stitching in newspaper assembly. The Reist patent’s rotary drum allowed the signatures to move closely together, reducing the speed at which they must move through the machine. The Reist rotary drum concept also permitted reduction of the distance between the signatures below the length of the signature — impossible on an in-line machine — and also enabled the machine to work with the shortest possible dimension or depth of paper. This design resulted in an extraordinarily high output capacity even though paper did not move through the rotary drum machine at the high speed which creates disturbing air flow in on-line machines. Specifically, the Reist machine included a horizontally elongated drum. In the embodiment shown in figures 1 to 6 of the Reist patent, the outer sheet or cover of a publication is fed into a drum between the dividing walls of a section of the drum as it rotates. As the drum rotates, the sheets move axially along the drum in a “generally helical” path until the sheets reach the second section of the drum. Pl.’s Findings of Fact ¶ 24. The path is only “generally helical” because, as illustrated in figure 2 of the Reist patent, the path actually becomes circular (i.e., no axial movement takes place) over the top of the drum. As the sheets rotate under the drum, an endless belt forms a kind of trough under the drum, preventing the sheets from falling out at the bottom of the drum’s cycle. After the sheets have rotated completely around the drum and have moved under the second feeding station, more sheets are inserted into the first section of the drum. The sheets continue to rotate with the drum and to move axially, following a “generally helical” path. Although the Reist patent disclosed a machine primarily for inserting or newspaper assembly, it also proposed some modifications: “the above described apparatus is not limited to the insertion of inserts into articles. ... [I]t is possible for numerous other operations to be performed_” Reist patent, col. 8, 11. 7-11. The relevant modification here is that the Reist patent claimed that: “Assembly may also take place from the inside to the outside, the innermost section being supplied to one end of the wheel and the successive further outwardly disposed sections being supplied subsequently.” Id. at col. 8,11. 36-37, 42-46. This statement strongly suggested that the Reist rotating drum machine could assemble sheets from the “outside to inside” in a pocket and could also assemble them from the “inside to outside” on a saddle. Although the Reist patent did not specifically state that “inside to outside” assembly occurs on a saddle, it is a necessary inference that “inside to outside” assembly is feasible only on a saddle such as traditionally used in an in-line machine. May 22, 1996 Trial Tr. at 15-16 (Boss cross). As early as 1980, Ferag produced and sold the Reist machine and quickly became identified with the high-capacity rotary drum concept in the bindery industry. Its commercial newspaper inserters were the state of the art and well-known in the industry, including Grapha. Pl.’s Ex. 395 (Grander dep. at 152-53). Ferag’s Reist rotary drum inserting machines were also a tremendous commercial success. To date, it has sold over sixty of these machines in the United States, including one at a newspaper bindery in Springfield, Illinois and another at Bergen, New Jersey. See Pl.’s Exs. 372, 373, 379 (Springfield); PL’s Exs. 381,382 (Bergen). In 1980, Ferag’s head of research and development at that time, Jacques Meier, used the Ferag rotary drum concept to design a rotating drum gatherer-stitcher. The U.S. patent for this design, the “Meier ’755” patent, U.S. Patent No. 4,408,755, issued on October 11,1983 based on a Swiss application filed March 11, 1980. The Meier ’755 patent shows a rotary dram with 24 saddles spaced evenly from each other around the drum’s circumference. On these saddles, webs of paper (as distinguished from individual sheets of paper) move axially along the length of the dram until they reach the drum’s end, where a rotating cylinder stitch — 1243 — ing apparatus at the end of the drum inserts staples serially on one set of sheets after another. In 1982, Ferag assigned a team of research and development engineers, namely, Werner Honegger, Egon Hanseh, and Erwin Muller, the task of designing a high speed, rotating drum gatherer-stitcher capable of operating on individual sheets of paper using the Reist patent’s rotary drum inserter technology. Muller’s initial responsibility was to perfect a stitching system for a rotating drum gathering machine. In the process, Muller conceived of an entire system for opening, gathering, and stitching signatures using the Reist rotating drum inserter. Although the Reist inserter used pockets for inserting, and not fins or saddles, it was well-known by 1980, as evidenced by the 1976 Macke patent, that the equipment used to accomplish different ways of assembling products, that is, inserting for newspapers and gatherer-stitching for magazines, could be broadly and flexibly combined to do either. See Pl.’s Ex. 71 (Macke patent); Pl.’s Ex. 389 (Higgins stmt, at 39). In his engineering drawings, completed in September and October 1982, Muller proposed a gathering drum for single sheets with a stitching unit for each gathering fin or saddle; Muller also proposed that each sheet be opened and placed in a straddling relationship on the saddles. See Pl.’s Ex. 391 (tabs 3-15). After this initial design work in 1982, Fer-ag did not immediately pursue a rotary drum gatherer-stitcher nor did it seek a patent on Muller’s concept; it believed that the system was covered by the Reist patent. May 15, 1996 Trial Tr. at 124-25, 148-50 (Muller direct, cross). Two years later, in April 1984, Ferag turned once again to the task of designing a high speed, rotary drum gatherer-stitcher and assigned it to Egon Hanseh, one of the original engineers on the project in 1982. From April 1984 to July 1986, Hanseh worked on the project using, as the nucleus for his design, Muller’s unpatented concept and the patented Reist rotary drum inserter technology, as well as the patented innovations of Meier and Macke. Hanseh considered two variations on the Reist rotary drum technology: a “Ferris wheel” drum, in which the sheets always remain vertical, and a “star-shaped” drum. Hanseh designed, among other things, the schematic drawings of an inside-to-outside-gathering, rotary drum saddle machine which could open and feed individual sheets onto the fins of a rotating drum using moving belts to prevent the product from falling off the fins when rotated to the bottom of the drum, drawn directly from the Reist invention. See Pl.’s Ex. 392 at tab 13. In so doing, Hanseh borrowed considerably from existing Reist inserter technology. For example, in designing the use of moving belts to prevent the product from falling off the fins when rotated to the bottom portion of the drum, he proposed using the same belts used on Ferag’s insert-er drums. The feeding mechanism he designed is identical to the feeding mechanism employed on the Reist inserter drum where the product is gripped at the fold. Ferag built and tested a prototype of the ferns wheel, rotary drum gatherer-stitcher in 1984. Between 1985 and mid-1986, Ferag continued to develop the ferns wheel rotary drum gatherer-stitcher and shipped a prototype of this design to a German client. In 1987, after studying the advantages and disadvantages of a number of variations of the rotary drum concept, Ferag replaced the fer-ris wheel approach with the star-shaped drum design. From 1987 to 1990, Ferag worked on the engineering and construction of a star-shaped rotary drum gatherer-stitch-er. In 1990, after the issuance of Grapha’s Weber patent, Ferag built and exhibited a prototype of the rotary drum gatherer-stitch-er at the DRUPA exhibition in Dusseldorf, Germany. Ferag modified this prototype and since 1993, has manufactured and sold it as the IPEX machine, which Grapha claims infringes the Weber patent. B. During this same time period, Grapha also considered using Ferag’s Reist rotating drum invention as the nucleus for a high speed, rotary drum gatherer-stitcher. In January 1982, having studied Ferag’s Reist inserter drum and the Reist patent, Heinz Boss, a Grapha engineer, concluded that single sheets could be assembled over the fins — 1244 — or panels of a rotating drum inserting machine. He recorded his ideas in a number of illustrations signed and dated January 1982. See Pl.’s Exs. 23, 33. His illustrations detail a rotating drum gatherer-stitcher having eight carriers, on which single sheets are deposited “inside to outside” over saddles. In August 1984, independent of the earlier design work of Heinz Boss and without any knowledge of it, Weber, also a Grapha engineer, designed the rotary drum gatherer-stitcher, which he patented and assigned to Grapha as the Weber patent. Like Boss, Weber was aware of Ferag’s Reist patent and inserter drum. Weber recorded his work in, among other documents, a morphological box in which he divided tasks to be performed by a machine into partial functions and sources where one could look for solutions to each part of the problem. Pl.’s Ex. 5. From this morphological box, he could determine the best solution to particular problems. Column 5 of this box addressed how to put a signature over or into another signature. In Box D-5, Weber suggested the solution as the inserting process of the Reist patent. Boxes F-10 and F-ll in the morphological box also illustrate the Reist rotating-drum concept. Weber also wrote a “Study Report,” in which he detailed the results of his experimentation and work and discussed the pertinent prior art and possible patent protection. In it, he noted that “there will have to be a comprehensive and clear delineation of features in terms of patent protection since a similar design approach already exists in the realm of newspaper processing.” Pl.’s Ex. 21 at 6. This “design approach” was Ferag’s Reist inserter drum. And the same advantages claimed by Weber in his patent — that a rotary drum machine would reduce the axial speed of the sheets thereby eliminating the problems associated with paper traveling at high speeds and reduce the abrupt changes in the direction of the paper — were those achieved by Ferag’s Reist inserter machine. Although it has always been Grapha’s goal to increase the speed of its gatherer-stitcher to equal that of the printing presses and although Grapha considered Weber’s design to be revolutionary, Grapha never made either of the rotary drum gatherer-stitchers described in Weber nor made a machine covered by any claim of the Weber patent. Stip. Facts ¶¶38, 39, 40. Grapha did not attempt to commercialize the Weber patent because it believed, among other things, that in 1985, the market was not ready for rotary drum gatherer-stitcher. May 22, 1996 Trial Tr. at 38 (Boss cross). Furthermore, Grapha realized that by 1985, because of the Reist inserter drum, the rotating drum principle had become Ferag’s marketing image, so that Grapha’s manufacture of a rotary drum could be perceived as a “me-too” to Ferag’s Reist rotating drum inserter. May 22, 1996 Trial Tr. at 38-42 (Boss cross); Pl.’s Ex. 395 (Grander dep. at 80-81). III. A. The legal principles applicable to the foregoing facts are not in serious dispute. As a matter of statute, Grapha’s Weber patent-in-suit “shall be presumed valid.” 35 U.S.C. § 282. It remains valid until the party asserting invalidity proves by “clear and convincing evidence” that the patent “is no longer viable as an enforceable right.” Roper Corp. v. Litton Sys., Inc., 757 F.2d 1266, 1270 (Fed.Cir.1985). Nevertheless, it was long ago established that “[i]t was never the object of [the patent] laws to grant a monopoly for every trifling device, every shadow of a shade of an idea, which would naturally and spontaneously occur to any skilled mechanic or operator in the ordinary progress of manufactures. Such an indiscriminate creation of exclusive privileges tends rather to obstruct than to stimulate invention.” Atlantic Works v. Brady, 107 U.S. 192, 200, 2 S.Ct. 225, 231, 27 L.Ed. 438 (1883); see also Goodyear Tire & Rubber Co. v. Ray-O-Vac Co., 321 U.S. 275, 279, 64 S.Ct. 593, 594-95, 88 L.Ed. 721 (1944) (Black, J., dissenting). Indeed, to justify the issuance of a patent, a “genuine ‘invention’ or ‘discovery’ must be demonstrated ‘lest in the constant demand for new appliances the heavy hand of tribute be laid on each slight technological advance in the art.’ ” Sears, Roebuck & Co. v. Stiffel Co., 376 U.S. 225, 230, 84 S.Ct. 784, 788, 11 L.Ed.2d 661 (1964) (Black, — 1245 — J.) (quoting Cuno Engineering Corp. v. Automatic Devices Corp., 314 U.S. 84, 92, 62 S.Ct. 37, 41, 86 L.Ed. 58 (1941)). Therefore, a patent may not be obtained for the product of mere mechanical sMU or for simply carrying forward the application of a prior device with a change only in degree. See Phillips v. Detroit, 111 U.S. 604, 608, 4 S.Ct. 580, 582-83, 28 L.Ed. 532 (1884); Smith v. Nichols, 88 U.S. 112, 22 L.Ed. 566 (1874). Ferag identifies five independent grounds for its challenge to the validity of the Weber patent, any one of which would invalidate the patent. Specifically, Ferag argues that the Weber patent is invalid because: (1) it defines a gatherer-stitcher machine that was known before Weber designed his machine and that the concept of the Weber machine was obvious to those of ordinary skill in the art prior to June 1985, the date the Weber patent application was first filed in Switzerland, in violation of 35 U.S.C. § 103; (2) it fails to disclose the best mode of the invention as required by 35 U.S.C. § 112, ¶ 1; (3) it does not contain an enabling disclosure as required by 35 U.S.C. § 112, ¶ 1; (4) it lacks utility as required by 35 U.S.C. § 101; and (5) certain of its claims are not definite as required by 35 U.S.C. § 112, ¶2. In the circumstances here, it is unnecessary to resolve the issues of best mode, utility, and indefiniteness. Ferag has shown by clear and convincing evidence that, at the time of its filing, Weber’s invention was invalid because the claimed invention was obvious to those of ordinary skill in the art within the meaning of 35 U.S.C. § 103, and does not contain an enabling disclosure as required by 35 U.S.C. § 112. B. It is black letter patent law that if the differences between the subject matter sought to be patented and the prior art would have been obvious at the time the invention was made to a person having ordinary skill in the art to which the subject matter pertains, that subject matter is not patentable. 35 U.S.C. § 103. The resolution of an issue with respect to obviousness requires four factual inquiries as to: (1) the scope and content of the prior art; (2) the differences between the claimed invention and the prior art; (3) the level of ordinary skill in the art at the time of the invention; and (4) objective evidence of obviousness or nonobviousness. See Graham v. John Deere Co., 383 U.S. 1, 17-18, 86 S.Ct. 684, 693-94, 15 L.Ed.2d 545 (1966). The scope of the prior art is evidenced by public information “reasonably pertinent to the particular problem with which the inventor was involved.” Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1535 (Fed.Cir.1983). The problem confronting both parties was how to make the bindery machine faster than the standard in-line gathering machine. The rotary drum insert-er had already achieved an output of 40,000 newspaper copies per hour. Its concept was the obvious point of departure to gatherer-stitching for magazines. Acknowledging its debt to the Reist inserter, Grapha nevertheless asserts that in June 1985, the prior art did not disclose a rotary drum gathererstitcher which deposited, transported, accumulated, and stitched individual folded sheets along the tops of the fins of a drum; and that therefore, the Weber invention was patentable. Ferag counters that the elements of the Weber patent were already disclosed by a combination of the Reist patent or inserting machine, the Macke patent, the Meier ’755 patent, the Meier ’754 patent, and the Meier ’930 patent.2 The Patent and Trademark Office cited and considered the Reist patent during the prosecution of the Weber patent. It apparently did not cite or consider the Macke patent and the Meier ’755 patent. When an accused infringer attacks the validity of the patent on the basis of prior art already considered by the Patent and Trademark Office, as is the case with the Reist patent, the presumption of patent validity is more difficult to overcome because of the deference — 1246 — due to a qualified government agency presumed to have properly done its job. American Hoist & Derrick Co. v. Sowa & Sons, Inc., 725 F.2d 1350, 1359 (Fed.Cir.1984). Nevertheless, I find that the Reist patent clearly and convincingly suggested the Weber device when Reist claimed that the “above-described embodiments may be used for performing a variety of operations,” such as assembling “from the inside to the outside.” Reist patent, col. 8, 11. 34-43. I also find that the Reist patent, the Reist inserter, the Macke patent, and the Meier ’755 patent disclose all the necessary elements of the Weber patent and, furthermore, teach that such elements may be combined in order to produce a rotary drum gatherer-stitcher. The Reist patent and the Reist commercial inserter teach that the speed with which signatures could be assembled on linear carriers would be increased by mounting a plurality of the carriers in a drum-like arrangement and rotating the carriers past signature feeding devices while transporting the signatures axially. This is precisely the principal advantage sought by the Weber patent. Furthermore, although the Reist patent pri-. marily shows a rotary drum machine for inserting folded sheets into newspapers, it also teaches to a person skilled in the art that the invention it described could be configured to gather sheets from “inside-to-outside” in the manner of magazine assembly. See Reist patent, col. 8,11. 36-37, 42-46; May 17, 1996 Trial Tr. at 435-36 (Higgins cross); May 22, 1996 Trial Tr. at 15-16 (Boss cross). The “Macke” patent, U.S. Patent No. 3,938,799, which issued on February 17,1976, discloses an inserting machine for assembling individual folded sheets in which, on a fin shaped like a partial “W”, one can assemble sheets in a side-by-side relationship between two fins, as in figure 3C of the patent, or gather them inside-to-outside on top of one of the fins, as in figure 4C of the patent. Pl.’s Ex. 71. Macke suggests to those skilled in the art to gather signatures on top of the fins in a machine such as the invention described in Reist. Pl.’s Ex. 389. It also shows that for inside-to-outside magazine assembly, an accumulation of sheets in a rotary drum may be placed so that the folded edge of each sheet is astride the fin instead of in a pocket between fins, and each sheet rests fold up with its open ends at the bottom of adjacent pockets. Therefore, when Reist discussed the inside-to-outside assembly as one of its modifications, it suggested a combination of Reist and Macke. Ferag’s “Meier ’755” patent, U.S. Patent No. 4,408,755, which issued on October 11, 1983, discloses a rotary drum gatherer-stitch-er that operates on a continuous web of paper, as distinguished from individual sheets. See Ferag AG v. Grapha-Holding AG, 905 F.Supp. 1 (D.D.C.1995). This patent reinforces the teaching of Reist: a rotating drum used in newspaper assembly in which there was no stitching can be used as a gatherer-stitcher for assembling magazines. By itself, the Meier ’755 patent teaches that a plurality of saddle-stitcher carriers mounted in drum-like fashion and rotated about a common axis, with a complementary rotating drum stitching mechanism for stapling sheet assemblies on the drum after gathering, can convert an inserter into a gatherer-stitcher. The obviousness of the machine claimed by the Weber patent is buttressed by Ferag’s demonstration of the level of ordinary skill in the art. The parties have stipulated that the level of ordinary skill in the art at the time Weber made his invention was that of a “person skilled in mechanical engineering by education or training, with 10 or more years of experience in designing and building newspaper and/or magazine sheet assembly equipment.” Stip. Fact. ¶ 55. To a person of ordinary skill in the art, the Reist inserter suggested the use of multiple saddles arranged in drum-like fashion and adapted to act as a gathering machine. Indeed, Ferag’s witness George Higgins, a persuasive example of a person of ordinary skill in the art, reached this conclusion when he inspected the Springfield, Illinois, Reist inserter in the early 1980s. May 16, 1996 Trial Tr. at 260 (Higgins direct). Kenneth Field, the chief executive officer of a commercial printer, who has over 20 years of experience in the bindery industry, stated his understanding of the rotary drum gatherer-stitcher to be that the inserter “had just been turned around. Instead of inserting, [Ferag was] using it as — 1247 — a collator, as a gatherer on this drum-” Pl.’s Ex. 395 (Field dep. at 18) (designated by both parties). In addition, three individuals independently conceived of the Weber patented device prior to Weber’s conception of it in 1984. See supra at 1242-1243. Although their work does not constitute “prior art,” these contemporaneous suggestions — the Boss, Muller, and Hansch sketches and engineering notebook pages — provide cumulative evidence probative of the level of knowledge in the art at the time the Weber idea was disclosed, unembellished by hindsight. See In re Merck & Co., Inc., 800 F.2d 1091, 1098 (Fed.Cir.1986); Vandenberg v. Dairy Equipment Co., 740 F.2d 1560, 1567-68 (Fed.Cir.1984). Such sketches confirm a core point: it would have been obvious to one of ordinary skill in the art at that time to use the Reist rotary drum as a gatherer-inserter for individual sheets. See Pl.’s Ex. 391 (tabs 3-15) (Muller drawings); Pl.’s Ex. 392 (Hansch drawings); PL’s Exs. 23, 33 (Boss drawings). Finally, in resolving the question of obviousness, there remains for consideration the objective indicia of non-obviousness. See Graham v. John Deere Co., 383 U.S. 1, 17, 86 S.Ct. 684, 693-94, 15 L.Ed.2d 545 (1966). These are the “secondary considerations” which “give light to the circumstances surrounding the origin of the [patented] subject matter,” such as the commercial success of the patented invention, the long-felt need in the industry for a successful rotary gatherer-stitcher, and the attempts and failures by others to design such rotary gatherer-stitch-er. See Cable Elec. Products, Inc. v. Genmark, Inc., 770 F.2d 1015, 1026 (Fed.Cir.1985). These “objective factors” provide “real world experience” of how the market viewed the patented device. Rosemount, Inc. v. Beckman Instruments, Inc., 727 F.2d 1540, 1546 (Fed.Cir.1984). A product’s commercial success would corroborate a finding of nonobviousness, and vice versa. For evidence about objective considerations to be given substantial weight, a “nexus between the merits of the claimed invention and the evidence of secondary considerations is required. ...” Cable Elec. Products, Inc., 770 F.2d at 1026. Commercial success is defined by a number of factors considered together: namely, number of units sold, market share, growth in market share, replacing earlier units sold by others or of dollar amounts, and evidence of a nexus between the sales and the merits of the invention. See Kansas Jack, Inc. v. Kuhn, 719 F.2d 1144, 1151 (Fed.Cir.1983). On the “totality of the evidence,” I do not find that “commercial success” requires a holding that the Weber patent would have been nonobvious at the time it was invented to one skilled in the art. Grapha contends that Ferag’s marketing materials, in which Ferag states that the IPEX machine is “the first breakthrough in stitching operation in 40 years,” constitutes evidence of commercial success. However, marketing or advertising is not a factor of commercial success as defined by the Federal Circuit in Kansas Jack. Moreover, even if it were, that Grapha has not manufactured any machine covered by any claim of the Weber patent undercuts its assertion that Ferag’s IPEX machine is a commercial success: it is reasonable to infer that if the rotary drum gatherer-stitcher were a commercial success, Grapha would attempt to enter that market by manufacturing its own rotary drum gatherer-stitcher. And indeed, the six IPEX machines, all sold in the U.S., are the only evidence of commercial success (compared with the 60 Reist machines and unnumbered in-line devices sold and operating). There is no evidence of market share, of growth in market share, or of replacing earlier units sold by others or of dollar amounts. The IPEX machine’s relative lack of commercial success buttresses the finding that the Weber patent is obvious, just as the Reist inserter’s commercial success only reinforces that it was, indeed, a groundbreaking and revolutionary advance in the bindery industry. Furthermore, the sales of Ferag’s rotary drum gatherer-stitcher are due, in part, to a feature not claimed in the Weber patent, and therefore, the nexus between the sales and claimed merits of the invention is considerably weak. Kenneth Field, the chief executive officer of a commercial printing company, stated that he decided to purchase the — 1248 — IPEX machine because it wasted no product. During a four-hour demonstration, the machine never stopped because it has the “intelligence” to recognize a “bad signature” and reject it quickly. See PL’s Ex. 365 (Field dep. at 19). The Weber patent neither claims nor suggests a manner in which the integrity of the accumulation of sheets can be consistently monitored. Grapha also contends that the Weber patent solved a long-felt need in the industry. However, even though there was always a need for more productive bindery equipment, Grapha’s own witness, Heinz Boss, testified that it did not pursue manufacturing and commercializing the Weber patent because the market was not ready for such a machine. May 22, 1996 Trial Tr. at 38 (Boss cross). Grapha also contends that Ferag’s development of the rotary drum gatherer-stitcher from 1982 to 1990 shows prior attempts and failures of others. However, Ferag has established that its activity was intermittent because of company demands for development of other products. See May 16, 1996 Trial Tr. at 203 (Hansch cross). The interrupted development by Ferag’s engineers actually reinforces the finding that there was no significant need for a rotary drum gatherer-stitcher machine; and in fact, there was a two-year hiatus in the design history of a rotary drum gatherer-stitcher by both Ferag and Grapha. The foregoing considered, I find and conclude that on the basis of the obviousness, claim 1 of the Weber patent is invalid. C. Grapha’s Weber patent is also invalid because it does not enable one skilled in the art to make and use the embodiments of the patent depicted in figure 1 or in figures 2-4. At the time the application is filed, the patent specification must “contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art ... to make and use the same.” 35 U.S.C. § 112. To be enabling under § 112, the patent specification must teach those skilled in the art how to make and use the full scope of the claimed invention without “undue experimentation.” In re Wright, 999 F.2d 1557, 1561 (Fed.Cir.1993); see Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1384 (Fed.Cir.1986), cert. denied, 480 U.S. 947, 107 S.Ct. 1606, 94 L.Ed.2d 792 (1987). Factors to be considered in determining whether a disclosure would require undue experimentation include, among other things: (1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, and (6) the relative skill of those in that art. In re Wands, 858 F.2d 731, 737 (Fed.Cir.1988). The embodiments of figures 1 and 2-4 of the Weber patent are nonfunctional as disclosed because one skilled in the art could not get the sheet on the carrier and between the carriers and the guides. Ferag presented the clear and convincing testimony of its independent witness, George Higgins, who stated that the sheet feeding units disclosed in the Weber patent are inherently incapable of opening and inserting sheets between the guides bracketing the carriers, whether the carriers are rotating past the feed units or are stationary. See Pl.’s Ex. 389 at 34-36 (Higgins stmt.). As Ferag argued, that is because, as seen in Grapha’s U.S. Patent No. 3,199,862, which is cited in the patent as exemplary, the panel edges of the folded sheets are pulled far apart before the sheet is released onto a stationary carrier. In order for the feeding units properly to insert the sheets between the guides, the guides would necessarily be so far apart as to be worthless for their intended purpose, i.e., to “confine the panel of folded sheets 5” so as “to prevent uncontrolled further spreading or opening ...” of the sheets. See Weber patent, col. 5, 11. 6-14. Furthermore, if the carriers and guides are rotating past the feeding units, the feeding units could not properly insert sheets in between the carriers and the guides. As Higgins convincingly demonstrated, the signature would “have to get inside of here somehow [a narrow space between the fin and the guide] and then fall down over that fin. It simply can’t be done.” — 1249 — May 15, 1996 Trial Tr. at 250 (Higgins direct). Grapha’s expert witness on engineering, Gary Gabriele, outlined an approach suggests ing how the figure 1 embodiment illustrated in the Weber patent could be made to work provided a number of modifications are made. However, even if, with these modifications, a functional machine could be realized, it would take a skilled engineer in the bindery industry four to six years to carry out Dr. Gabriele’s approach. May 16, 1996 Trial Tr. at 256 (Higgins direct). The years of effort required to discover how to make and use the alleged Weber invention constitutes more than routine or ordinary effort. See White Consol. Indus., Inc. v. Vega Servo-Control, Inc., 713 F.2d 788, 791 (Fed.Cir.1983) (finding 1)6 to 2 man years to develop the invention unreasonable). Given the lack of guidance and direction provided by the specification and the quantity of experimentation required, the Weber patent requires “undue experimentation” to practice the invention and therefore is nonenabling under 35 U.S.C. § 112. The fact that defendant has not made a machine covered by any claim of the Weber patent corroborates this finding. If the patent did disclose an enabling device, and if, as defendant contends, there currently exists a market for the high-speed rotary drum gatherer-stitcher, defendant’s failure to make such a machine leads to the reasonable inference that the patent does not disclose, in “full, clear, concise, and exact terms,” the information as “to enable any person skilled in the art ... to make and use the same.” IV. A. As the Federal Circuit has noted, “when presented with patent validity and infringement issues, trial courts should ... decide both.” Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1540 (Fed.Cir.1983). Therefore, although as a matter of law there can be no infringement of an invalid claim, and Section III of this Memorandum holds that claim 1 of Grapha’s Weber patent is invalid, the infringement issue must be addressed. The difference between the two issues may be stated succinctly: resolving invalidity on the basis of obviousness requires comparing the Weber patent with the prior art; whereas resolving infringement requires comparing the Weber patent with subsequent developments. Treating the Weber patent as valid for purposes of infringement analysis only, I find and conclude that Ferag’s IPEX machine does not infringe the patent. As the patentee, Grapha has the burden of proving by a preponderance of the evidence that the accused devices embodies every element of the claim as properly construed, either literally or by operation of the doctrine of equivalents. Absence of any “element” or “limitation” (the terms are essentially synonymous) requires a finding of non-infringement. Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1389 (Fed.Cir.1992) (“As this court has repeatedly stated, infringement requires that every limitation of a claim be met literally or by a substantial equivalent.”) (emphasis in original). Under the doctrine of equivalents, “infringement may be found ... if an accused device performs substantially the same overall function or work, in substantially the same way, to obtain substantially the same overall result as the claimed invention.” Graver Tank & Mfg. Co. v. Linde Air Products Co., 339 U.S. 605, 607-08, 70 S.Ct. 854, 855-56, 94 L.Ed. 1097 (1950). However, an accused device’s performance of the same function “will not make [it] an infringement under the doctrine of equivalents where it performs the function and achieves the result in a substantially different way.” Perkin-Elmer Corp. v. Westinghouse Elec. Corp., 822 F.2d 1528, 1531 n. 6 (Fed.Cir.1987) (emphasis added). As the Federal Circuit recently observed, “the doctrine of equivalents is the exception, however, not the rule, for if the public comes to believe (or fear) that the language of patent claims can never be relied on, and that the doctrine of equivalents is simply the second prong of every infringement charge, regularly available to extend protection beyond the scope of the claims, then claims will cease to serve their intended purpose.” Lon — 1250 — don v. Carson Pirie Scott & Co., 946 F.2d 1534, 1538 (Fed.Cir.1991). Analysis of a patent infringement claim entails two inquiries: first, the legal interpretation of the scope of the claims; and second, the factual finding of whether the properly construed claims encompass the accused structure. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 976 (Fed.Cir.1995), aff'd, — U.S. —, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996). The issue of infringement in this case centers on claim 1, which is the Weber patent’s only independent claim. To avoid infringement, Ferag need show only the noninfringement of independent claim 1 because a dependent claim cannot be infringed unless the accused device is also covered by the related independent claim. See Wolverine World Wide, Inc. v. Nike, Inc., 38 F.3d 1192, 1199 (Fed.Cir.1994). Weber’s claim 1 describes as an invention: A machine for accumulating folded sheets into brochures and like products, comprising: a sheet transporting device arranged to advance sheets having folded backs in a predetermined direction along a predetermined path and including at least two elongated parallel carriers and discrete conveyor means for each of said carriers, each of said conveyor means having means for advancing sheets along the respective carrier; and means for feeding sheets to said carriers so that the backs of the sheets straddle the respective carriers, comprising a first feeding unit having means for depositing first sheets onto successive carriers in a first portion of said path and at least one additional feeding unit having means for depositing second sheets over successive first sheets in a second portion of said path downstream of the first portion so that the backs of the second sheets straddle the backs of the respective first sheets and form therewith accumulations of the first and second sheets wherein the backs of the second sheets are accessible. Col. 9,11. 31-49. The parties agree that the following elements of Weber’s claim 1 are in dispute: (1) the “sheet transporting device ... to advance sheets ... (2) in a predetermined direction along a predetermined path; (3) “means for feeding sheets”; (4) “discrete conveyor means”; and (5) “means for advancing sheets”. See Pl.’s Concl. of Law at ¶¶ 19-26; Def.’s Concl. of Law at ¶¶ 48-77. Of these five disputed elements in the Weber patent, only one of the five is offended by the Ferag products. As the Federal Circuit has repeatedly held that infringement requires that every limitation of a claim be met literally or by a substantial equivalent, and because the other four disputed elements or limitations in the Weber patent are either not performed by or not incorporated in the structure of the Ferag products at issue here, the Ferag rotary drum gatherer-stitchers do not infringe the Weber patent. See Intellicall, Inc., 952 F.2d at 1388-89. B. Claim 1 of the Weber patent discloses a “sheet transporting device arranged to advance sheets having folded backs in a predetermined direction along a predetermined path and including at least two elongated parallel carriers and discrete conveyor means for each of said carriers, each of said conveyors having means for advancing sheets along the respective carrier....” Ferag contends that the “sheet transporting device” should be construed as having six elements: a shaft, a hub, carriers, plate-like guides, chain conveyors, and pushers. These are the elements numbered 1 to 6 in figure 1 of the patent. Ferag states that this construction finds support in the Weber patent specification, which in the “description of the preferred embodiments” refers to “sheet transporting device” as follows: “The guides 4, chain conveyors and pushers (not specifically shown) are identical with or analogous to the parts 4, 5 and 6 of the sheet transporting device 1-6 in the machine of FIG. 1.” See Weber patent, col. 7,11.13-15 (emphasis added). To buttress this interpretation, Ferag refers to the prosecution history of the Weber patent, in which the attorney prosecuting the Weber patent application before the U.S. Patent and Trademark Office referred to the sheet transporting device “as the device 1-6 of Fig. 1.” Pl.’s Ex. 2 at 77. In construing the specific language of a claim, “[w]ords ... “will be given their ordi — 1251 — nary ... meaning, unless it appears that the inventor used them differently.’” Envirotech Corp. v. Al George, Inc., 730 F.2d 753, 759 (Fed.Cir.1984). “[C]laims are not to be interpreted by adding limitations appearing only in the specification.... [Although the specification may well indicate that certain embodiments are preferred, particular embodiments appearing in a specification will not be read into the claims when the claim language is broader than such embodiments.” Electro Medical Systems, S.A. v. Cooper Life Sciences, Inc., 34 F.3d 1048, 1054 (Fed.Cir.1994). Ferag’s proposed interpretation of “sheet transporting device” fails to overcome the clear language in the claim as to the meaning of the term. The language in the specification and the reference in the prosecution history describing the sheet transporting device as including elements “1-6” simply describe two embodiments of the claimed invention, i.e., that shown in figure 1, and that shown in figures 2 to 4. These references do not control the meaning of “sheet transporting device,” which is defined in the claim: it covers a drum and “includes at least two elongated parallel carriers, each carrier having discrete conveyor means.” Ferag’s proposed interpretation would violate the rule that particular embodiments appearing in a specification should not be read into the claims when the claim language is broader than such embodiments, and it would also violate the rule of claim construction prohibiting “double inclusion.” Ex parte Kristensen, 10 U.S.P.Q.2d 1701, 1703 (Bd. Pat. Appeals 1989). If “sheet transporting device” is interpreted as proposed by Ferag, that is, as including elements 1 to 6 described in the specification — shaft, hub, carriers, guides, endless chain conveyors, and pushers — then the subsequent language in claim 1 defining the elements of the sheet transporting device as including carriers, conveyors, and advancing means would be “doubly included” and superfluous. As interpreted, the “sheet transporting device” element of claim 1 literally reads onto Ferag’s IPEX machine because Ferag’s IPEX machine has a drum and “at least two elongated parallel carriers, each carrier having discrete conveyor means.” C. The clause of claim 1 set forth above also requires that each deposited sheet move in a “predetermined direction along a predetermined path.” Weber patent, col. 9,11. 34r-35. Grapha asserts that this phrase means only that the sheets must travel on the drum axially from one end to the other along a “non-random” path, and that the plain meaning of this language does not require that the path be helical. A “non-random” path ensures that each sheet will be properly positioned with respect to subsequent sheet feeding units or other elements of the machine, and arrives at the proper time and in the proper alignment. Hence, the path may be, but is not required to be, helical. Ferag reads this language in the Weber patent as requiring a helical path because the only path described in the Weber patent is a helical path, and in fact, no other path could be created because in the Weber machine, there is constant axial and rotational movement. Ferag points out that the patent specification states, “a sheet transporting device which serves to advance folded sheets in a predetermined direction (preferably along a helical path)” and further states, “moving the sheets on the carriers in parallelism with the axis so that the sheets advance along the aforementioned helical path.” Weber patent, col. 3,11.11-14,48-50. Grapha responds that Ferag’s reading violates the doctrine of claim differentiation, which requires that claims should be presumed to cover different inventions. Claim 20 of the Weber patent claims “[t]he machine of claim 1, wherein said path is a helical path.” Because Claim 20 claims a “helical path,” the “predetermined path” in Claim 1 cannot mean “helical”: “ ‘[A]n interpretation of a claim should be avoided if it would make the claim read like another one.’ ” Laitram Corp. v. Rexnord, Inc., 939 F.2d 1533, 1538 (Fed.Cir.1991). The doctrine of claim differentiation is not a hard and fast rule, however; indeed, “ ‘[i]f a claim will bear only one interpretation, similarity will have to be tolerated.’ ” Id. In — 1252 — the Weber patent, a “helical” path is the only-interpretation the element “predetermined path” can bear. The Weber patent teaches against changing the direction of the sheets, and therefore, requires a continuous rotational and axial movement, which results in a helical path. Although the patent does state that a helical path is “preferable,” there is no other path that could be created by application of the Weber patent. As interpreted, this element does not read onto the IPEX machine either literally or under the doctrine of equivalents. Ferag’s IPEX machine moves sheets in a stepwise fashion, not helical. The axial motion of the sheets is not continuous in the IPEX machine. Indeed, during 75% of a revolution, the sheets do not move axially, only circularly. Axial and circular motion occur together in less than 25% of a revolution, which creates only a small section of a helix. May 15, 1996 Trial Tr. at 48 (Felix direct). Therefore, there is no literal infringement. Even under the doctrine of equivalents, there is no infringement because there are substantial differences between a stepwise path and a helical path. Principally, the stepwise path allows for the alignment of sheets because the absence of continuous axial movement permits the operator of the IPEX machine to monitor the quality of the gathered product. One of the major advantages of the IPEX machine is its ability to monitor product integrity throughout the binding process. See Pl.’s Ex. 395 (Field dep. at 20-21). Furthermore, the stepwise path avoids the problem of having axial movement on the bottom side of the drum, where the sheet would rub against the belts. Therefore, Grapha’s helical path and Ferag’s stepwise path are substantially different in manner and in result. D. Claim 1 also requires that each carrier include “discrete conveyor means.” When a claim element is expressed as a means or step for performing a specified function without the recital of structure, material, acts, or acts in support thereof, the element is interpreted pursuant to 35 U.S.C. § 112, ¶ 6. This paragraph states that a means-plus-function clause covers the structure disclosed in the patent and any equivalent of the structure which is described in the patent specification as performing that function. Valmont Indus., Inc. v. Reinke Mfg. Co., 983 F.2d 1039, 1043 (Fed.Cir.1993). For a means-plus-function limitation to read literally onto Ferag’s accused devices, the accused device must (1) employ means identical or equivalent to the structure, material, or acts described in the Weber patent specification, and (2) perform the identical function specified in the asserted claims. King Instruments Corp. v. Perego, 65 F.3d 941, 945-46 (Fed.Cir.1995), cert. denied, — U.S. —, 116 S.Ct. 1675, 134 L.Ed.2d 778 (1996). The structure in the Weber specification for performing the “discrete conveying means” function (conveying each sheet along the carrier) is the “discrete endless chain conveyor” numbered 5 in figure 1 of the patent. Weber patent, col. 5,11.15-16. This chain conveyor is similar to the sprockets and chains used on a bicycle and is located inside the carrier. In order to maintain the helical movement of the sheets, the chain must move continuously along the axis of the drum. The chain cannot stop and restart or reverse directions. Each carrier has its own separate and discrete chain conveyor, and each chain conveyor operates with pushers which advance deposited sheets in a predetermined direction. Unlike the Weber patent’s chain conveyor, Ferag’s IPEX machine does not use a chain conveyor, but rather conveys sheets by a reciprocating control slide. The control slide is a piece of metal that rides on the side of the fins of the drum. As the drum rotates, the control slide starts, pauses, and reverses axial direction movement, whereas the chain conveyor continuously moves axially without stopping or reversing direction. Given these differences, the control slide is not “identical” to the chain conveyor. Nevertheless, there can be literal infringement of the means-plus-function clause if there is an “equivalent” to the chain conveyor in the IPEX machine. In the context of section 112, “an equivalent results from an insubstantial change which adds nothing of significance to the structure, material, or acts disclosed in — 1253 — the patent specification.” Valmont Indus., Inc., 983 F.2d at 1043. The IPEX machine’s control slide is not the mechanical equivalent of the Weber patent’s chain conveyor; nor under the doctrine of equivalents is the IPEX machine’s control slide substantially similar in manner to Weber’s chain conveyor. The chain conveyor moves continuously without stopping or reversing direction, which allows for no time in which the product can be properly aligned and the integrity of the product cheeked. In contrast, the control slide starts, pauses, and reverses axial movement, which creates time to align the product and to monitor the product’s integrity. Moreover, this movement also enables the IPEX machine to move sheets into and out of the stitching station, in which time is needed for stapling, because the axial movement is not constant. Weber’s chain conveyor cannot achieve these advantages. E. Claim 1 further requires that “each of said conveyor means hav[e] means for advancing sheets along the respective carrier.” (emphasis added). Each conveyor includes a series of pushers such as pins, blocks, or other suitable means for advancing sheets along a respective carrier. These are defined in the specification as pins located at the top of the carrier, number 6 in figure 1 of the patent. Each pin touches a collection of sheets and actually pushes them along the length of the carrier in a helical path until the sheets reach the stapler, at which point the pin rotates down and returns to the beginning of the carrier. Because the pins are continuously moving, they cannot travel into or beyond the stapler. The patent states that “the pushers [ ] are designed to advance sheets [] all the way to but not beyond the [stapling] station,” Weber patent, col. 8,11. 32-34; and figure 1 shows that the pushers travel along paths which terminate at the stapling station. The pushers are the only structure disclosed as an advancing means in Weber. For a means-plus-function limitation to read literally onto Ferag’s accused devices, the accused device must (1) employ means identical or equivalent to the structure, material, or acts described in the Weber patent specification, and (2) perform the identical function specified in the asserted claims. King Instruments Corp. v. Perego, 65 F.3d 941, 945-46 (Fed.Cir.1995), cert. denied, — U.S. —, 116 S.Ct. 1675, 134 L.Ed.2d 778 (1996). Ferag’s IPEX machine does not employ “means identical or equivalent to the structure, material, or acts described in the Weber patent specification.” The IPEX machine does not have such pushers but rather, reciprocating wedges, which are only on one side of the fin, move back and forth, and do not travel the entire length of the machine. May 15, 1996 Trial Tr. at 50 (Felix direct). They drive a sheet for approximately one-fourth of a revolution and do not travel from one feeder to the next. In comparison, a pin on the Weber patent moves with the sheet or collection of sheets down the length of the entire carrier. With the IPEX machine, to advance a sheet from one feeder to the next or from the feeder to the stapler takes two different wedges and two drum revolutions. Hence, there is no identity or equivalence between the pushers of the Weber patent and the reciprocating wedges of the IPEX machine. There is also no infringement under the doctrine of equivalents because the IPEX machine’s wedges operate in a manner and obtain results substantially different from the manner and results that would attend the Weber pushers. On the IPEX machine, as the sheets move along the fin, a different wedge moves the sheet through each section of the machine and consequently beyond the stapler. A wedge goes into the stapler and another wedge goes beyond the stapler. This structure accomplishes a number of results not obtained in the Weber patent: first, because the wedges do not continuously move axially, there is no axial movement when the stapling takes place; second, the wedges are able to move axially after stapling, which allows the IPEX machine to have an exit station that is axially after the stapling section. There is no such exit station in the Weber patent. Indeed, if the Weber pushers moved into the staple section, the machine could not operate. — 1254 — F. Claim 1 of the Weber patent requires “means for feeding sheets to said carriers ..., comprising a first feeding unit having means for depositing first sheets onto successive carriers in a first portion of said path.” Weber patent, col. 9,11. 39-40. Because this is a means-plus-function clause, one must go to the specification to determine what the claimed “means” are and their equivalents. Weber has two different means for feeding sheets. The first feeding means, shown in figure 1, uses conventional drum feeders, such as that disclosed in the Muller ’862 patent, U.S. Patent No. 3,199,862. The second, shown in figure 3, has a ring of pockets with opening devices that rotate around the same axis as the drum. These are the only opening means disclosed in the Weber. The conventional drum feeder means is identified by number 7 or 8 in figure 1 of the Weber patent. Known in the bindery industry since the 1930s, these feeders use rotating drums to withdraw sheets from a stack. One of the drums grabs the sheet, takes it from the stack, and rotates it around until the grippers on the other drums grab it and change its direction. These grippers drop the sheets onto the carrier. These openers and depositors do not move with the rotating carriers and do not rotate around the axis of the drum. See May 30, 1996 Trial Tr. at 59 (Gabriele cross). Figure 3 of the Weber patent discloses a different feeding means. Here, sheets move into a rotating pocket; the openers rotate around the axis of the drum; and the sheets are pinched and then thrust onto a carrier. Each carrier has its own opening and depositing means which travel along the axis of the carrier. ■ Ferag’s IPEX machine does not use a drum feeder as shown in figure 1 of the Weber patent nor a mechanical equivalent to a drum feeder. Rather, IPEX uses gripper conveyors, a star wheel opener, and a feeder screw to position the sheets in the path of the fin on the drum. See PL’s Exs. 362,363, 425. In the IPEX feeding mechanism, one gripper conveyor carries a single sheet to the star wheel. This is essentially the same type of feeding mechanism Ferag uses for its commercial inserter. At the star wheel, the longer edge of the sheet is pushed into an open clamp, which then closes. A finger on the star wheel, called the “unpeeler”, opens the sheets. Once the sheet is opened, the feeder screw and the gripper conveyor move the opened sheet towards the drum. The fin rotates into the opened sheet, and the gripper then releases it. Unlike the feeding means disclosed in figure 1, the IPEX feeding mechanism is a fluid, smooth, continuous motion, and the sheets do not stop or start or change directions. Also, the fin touches the open sheet while the sheet is still controlled by the gripper conveyor, thereby greatly increasing sheet control and production rates. Hence, the IPEX machine does not employ means identical or equivalent to the structure, material, or acts described in figure 1 of the Weber patent specification, nor does the IPEX machine’s feeding mechanism operate in substantially the same way as does the means described in figure 1. Weber’s figure 3 embodiment of the feeding means rotates around the drum and along the length of the drum. See May 30, 1996 Trial Tr. at 60 (Gabriele cross). Accordingly, for there to be identity or equivalence between the figure 3 embodiment and the IPEX machine, the IPEX machine must also have a device for depositing sheets which moves along the length of the drum with the carriers. The means on the IPEX machine do not move along the length of the drum with the carriers; hence, there is no literal infringement. Moreover, under the doctrine of equivalents, substantial differences exist between how the product is gripped and opened in the respective machines. The IPEX machine grips the signature by the folded edge so the fin can enter the opened signature. The feeding means in Weber’s figure 3 grips the signature by the cut edge. Furthermore, Grapha’s witness acknowledged that the opener in the IPEX machine does not work similarly to the way in which the openers in figure 3 work; Gra-pha’s witness also testified that one of ordinary skill in the art would not think to substitute the opener in the IPEX machine for the opener of figure 3. May 30, 1996 Trial Tr. at 69-70 (Mayer direct). Accordingly, there is no infringement under the — 1255 — doctrine of equivalents of the means for feeding sheets element in the Weber patent. G. Because infringement requires that the accused device embody every element of the claim as properly construed, either literally or under the doctrine of equivalents, and because the IPEX machine does not embody the “predetermined direction in a predetermined path” element, the “discrete conveyor means” element, the “means for advancing sheets” element, and the “means for feeding sheets” element, the IPEX machine does not infringe claim 1 of the Weber patent. V. An accompanying Order grants judgment to Ferag that Grapha’s patent-in-suit is invalid and unenforceable, and that the patent-in-suit is not infringed by Ferag. ORDER For the reasons stated in the accompanying Memorandum, it is this 22 day of July 1996 hereby DECLARED: that defendant’s patent-in-suit is invalid and unenforceable; and it is further DECLARED: that plaintiffs’ rotary drum gatherer-stitchers would not infringe defendant’s patent-in-suit if it were valid; and it is further ORDERED: that, on plaintiffs’ complaint and defendant’s counterclaim, JUDGMENTS shall be entered for PLAINTIFFS and against DEFENDANT. — 1256 — APPENDIX A [[Image here]] [[Image here]] — 1257 — [[Image here]] — 1258 — [[Image here]] — 1259 — [[Image here]] — 1260 — [[Image here]] — 1261 — [[Image here]] — 1262 — [[Image here]] — 1263 — [[Image here]] — 1264 — [[Image here]] — 1265 — [[Image here]] — 1266 — [[Image here]] — 1267 — APPENDIX B [[Image here]] [[Image here]] — 1268 — [[Image here]] — 1269 — [[Image here]] — 1270 — [[Image here]] — 1271 — [[Image here]] — 1272 — [[Image here]] — 1273 — [[Image here]] — 1274 — [[Image here]] — 1275 — [[Image here]] — 1276 — [[Image here]] — 1277 — [[Image here]] — 1278 — [[Image here]] — 1279 — [[Image here]] — 1280 — [[Image here]] — 1281 — [[Image here]] — 1282 — [[Image here]] — 1283 — [[Image here]] Footnotes [1] For purposes of this litigation, the IPEX machine is representative of Ferag’s rotary-drum gatherer-stitchers. [2] As stated earlier, see supra at 1242-1243, in 1982 and in 1984, before Weber filed his Swiss application in June 1985, Ferag engineers had already drafted drawings of rotary drum gatherer-stitchers that were later used in the design and manufacture of the IPEX machine. These drawings were not public and therefore do not constitute "prior art.”