Full opinion text
OPINION ENSLEN, District Judge. This is an action for patent infringement with a counterclaim for patent Unenforceability and invalidity. Plaintiff, Haworth, Inc. (“Haworth”), formerly known as Ha-worth Mfg., Inc., is a Michigan corporation with its principal place of business in Holland, Michigan. Until about 1975, Haworth was known as Modem Partitions, Inc. and Modem Products, Inc. After 1975, the corporation was known as Haworth Mfg., Inc. In 1981, Haworth Mfg., Inc. was merged into the present Haworth, Inc. For convenience, plaintiff and its predecessors will be referred to collectively as “Haworth.” Defendant, Steelcase Inc. (“Steelcase”), is a corporation with its principal place of business in Grand Rapids, Michigan. Both parties manufacture office furniture and the instant litigation involves two Haworth patents relating to electrically pre-wired portable wall panels for use in large offices. Haworth filed its complaint November 8, 1985, charging Steelcase with infringement of two Haworth Patents, United States Reissue Patent No. Re. 31,733 (the ’733 patent) and United States Patent No. 4,370,008 (the ’008 patent). Both of those patents are entitled “Wall Panel with Prewired Power System.” The inventors named in both patents are Richard G. Ha-worth, Charles J. Saylor and Harold R. Wilson. Haworth argues that claims 8 and 26 of the ’733 patent and claims 5 and 29 of the ’008 patent are infringed by Steelcase’s Series 9000 and Valencia panels. Claims 5 and 29 of the ’008 patent are also asserted against Steelcase Moveable Wall Panels. At all relevant times, Haworth has been and is the owner of the ’733 patent in suit which was granted November 13, 1984, on application Serial No. 43,908, filed May 30, 1979, as an application for reissue of United States Patent No. 4,060,294 (the ’294 patent). The ’294 patent was granted November 29, 1977, on application Serial No. 615, 506, filed September 22, 1975. At all relevant times, Haworth has been and is the owner of the ’008 patent in suit which was granted January 25, 1983, on application Serial No. 142,911 filed April 23, 1980, as a continuation of application Serial No. 918,278, filed June 22, 1978 and now abandoned. The latter abandoned application was a continuation of application Serial No. 737,420, filed November 1, 1976, and now abandoned. That latter application, in turn, was a continuation-in-part (“C-I-P”) of the aforesaid application Serial No. 615,-506, filed September 22, 1975, that became the ’294 patent. A terminal disclaimer was filed in connection with the '008 patent so that it will expire on the same day as the ’733 patent in suit, namely, November 29, 1994. Steelcase’s answer of January 17, 1986, denied validity, infringement and enforceability of the two patents in suit. Additionally, Steelcase counterclaimed for judgment holding the patents in suit invalid, not infringed and unenforceable. Haworth’s reply of February 5,1986, denied all substantive allegations in Steelcase’s counterclaim. Background Facts The subject matter disclosed in each of the patents in suit is a portable panel used in office building environments to form wall or partition structures defining “work stations.” The Haworth panels are designed to be flexibly arranged so that a given assembled configuration of panels can be altered, without electrically disconnecting adjacent panels from each other. Each of the panels includes a pre-wired power system that allows any panel to be electrically connected to any adjacent panel by means of electrical components arranged within the confines of the panel and at the panel base. The electrical components in the pre-wired power system are the technological focus of this litigation. The design of the components illustrated in the patents was intended by the inventors so that each powered panel would be non-handed, and so that they neither required nor permitted the use of extension cords for electrically interconnecting one panel to other panels. This design was intended to attain Code approval in major cities throughout the country. In June, 1976, Haworth introduced to the market its wall panels having a pre-wired power system. Those panels were commercially designated “ERA 1.” The ERA 1 system was commercially successful. The first prototype of the ERA 1 power system was made in early 1976. It was a single-circuit, three-wire system. Steelcase was then, and is now, the world's largest manufacturer of office furniture. Since then, Haworth has become a major competitor of Steelcase’s. Haworth is now the third largest manufacturer of systems office furniture, ranking behind Steelcase and Herman Miller. Haworth now markets wall panels with pre-wired power systems under three different trademarks or commercial designations: ERA 1, TRICIRCUIT, and THE POWER BASE. This action arose as a result of the manufacture, use and sale by Steelcase, since 1978, of pre-wired power systems for wall panels identified by the commercial designations: “Series 9000”, “Movable Walls”, and “Valencia.” The accused Series 9000 panels were first introduced to the market in June 1978. The accused “Movable Walls” panels with their current power system were introduced to the market around 1982. The accused “Valencia” panels with a power system were first introduced to the market around 1983. The Haworth Inventions By at least 1974, Haworth perceived a need for a pre-wired power system for panels in the open office plan that would meet the requirements of the National Electric Code and local Code authorities in important cities throughout the country. Ha-worth decided to develop such a system. In 1974 and 1975, Harold VandenHoek was Director of Engineering at Haworth. VandenHoek Tr. at 1181-82. Charles J. Saylor was hired by Haworth in the latter part of 1974. Saylor Tr. at 392. Mr. Saylor’s assignment was to work in the design and development of a satisfactory pre-wired power system for panels. Id. Some of the important early Haworth conceptual decisions were that the prewired power system had to be nonhanded, that power could flow in either direction through the panel, and that each panel could be a “feeder panel” capable of receiving building power input at either end. JX 1055; SF 33(aHg). The Haworth panel system was designed to require a licensed electrician only for initially connecting the pre-wired electrification in the panels to the building power. It was also designed so that, when initially assembling and later rearranging the panels into different work station configurations, as needed, it was not necessary to initially hard-wire the panels after they were assembled together, or to disconnect and remove the wires in the panels prior to disassembly of these panels and then reinstall the conduit and wiring after the panels had been rearranged. SF 33(a). As conceived by the Haworth inventors, their pre-wired power system included two key non-handed components, so-called “power blocks” and “flexible electrical connectors.” The power blocks were at the heart of their system because of the many features they were designed to provide (the term “power block” was coined by the Ha-worth inventors). Saylor Tr. at 409. There were two power blocks in each powered panel with the flexible electrical connector being designed to be removably, electrically connected between the power blocks of adjacent panels. The power blocks disclosed in the patents in suit: (i) had an opening at their inner end for receiving the electric wires or cables that extended between power blocks in the panel base (through a channel referred to as a “raceway”) so that the two power blocks in each panel were in electrical communication with each other; (ii) had a first connection means for releasable electrical connection to the flexible electrical connector to electrically connect the power block of one panel to the power block of an adjacent panel; (iii) had a second connection means that was identical to the first electrical connection means, and arranged on the other side of the power block, for connection to a second flexible electrical connector, as would be required for connecting the power block of that panel to the power block of a third panel, for example, in a T or Y configuration of panels; (iv) had an external third electrical connection means in the form of a conventional receptacle for energizing electrical equipment to be utilized at the work station; (v) had a housing enclosing the necessary, internal wiring and electrical members for electrically connecting the wires running between the ends of the panel with the various connection means associated with the power block; and (vi) had means for bringing building power into the panel and for being hard wired at the other end, by a licensed electrician, to a floor monument or junction box in the building. SF 33(c). The power blocks and flexible connectors made the system non-handed so that each panel could be a feeder panel, yet be conveniently plugged into by the flexible electrical connectors, to electrically connect one panel to another, and with the panels being arranged either in line, or in an “L”, “T”, or “X” configuration. The power block permitted power to flow in either direction through the panel. A raceway structure was provided at the base of the panel to enclose the wiring yet provide a separate, isolated passageway for communication cables. The panels were mechanically hinged together by a separate plastic panel hinge in the manner of Haworth’s prior non-powered panels. When attached to adjacent panels, electrically connecting them together, the flexible connector had the capability of hinging approximately along the same vertical axis as the plastic mechanical panel hinge for the panels so that two mechanically and electrically connected panels could be pivoted or moved angularly, one relative to the other, without having to disconnect or modify the flexible electrical connector. This ability to pivot two connected panels about their panel hinge connection, while leaving the flexible electrical connector in place, provided flexibility for installation and reconfiguration of the panels. In April 1975, Haworth decided that additional technical assistance and design help were needed for the project. Harold Wilson was thereafter hired as a “contract” employee by no later than May 1975. SF 35; Wilson Tr. at 111-12. After being advised about the ideas for pre-wired panels which Messrs. Haworth and Saylor had been working on, Mr. Wilson then made a drawing showing a flexible connector and power blocks. Plaintiff’s Exhibit (“PX”) 1036. Wilson then designed a two-part plastic flexible connector with wires inside and a fixed pivot axis around which the two plastic parts hinged. PX 324, 375. The latter evolved into Haworth’s ERA 1 flexible connector. Three versions of that flexible connector are illustrated in the drawings of all Haworth’s patent applications leading to the two Haworth patents in suit. Richard Haworth and Charles Saylor met May 30, 1975, with Haworth’s patent counsel, Dale Thiel, a registered patent attorney from Kalamazoo, Michigan. SF 36. During that meeting, Thiel was given drawings of the Haworth developments and was instructed to prepare a patent application. JX 1004, p. 60; PX 1036; JX 1030-31. Thiel then proceeded to have patent drawings made. Thiel Tr. 1834-39. Meanwhile, Messrs. Haworth, Saylor, and Wilson were proceeding with further developmental and refinement work. That work led to some modifications of the structures shown in the drawings provided to Thiel at the May 30, 1975 meeting. Drawings for those modifications were given to Thiel and he continued with the patent application so that it included the modifications. By late summer 1975 the application was revised to include further refinements, and the application was filed on September 22, 1975, listing only Messrs. Haworth and Saylor as inventors. It was identified as Serial No. 615,506. It illustrated a wall system including panels hinged together, each panel having two power blocks fixedly mounted adjacent to each end, which could be electrically connected by a hinging flexible connector. SF 37. On or about August 4, 1976, Dale Thiel, after due investigation, amended the Ha-worth September 22, 1975 patent application Serial No. 615,506 to include Wilson as a co-inventor. SF 38. Mr. Wilson did not start to work on the ERA 1 project until after he joined Haworth as a “contract” employee by no later than late May 1975. Wilson Tr. 111-12. Mr. Wilson was not hired as a regular Haworth employee until early August 1975. Id. On July 1, 1976, all three named inventors signed a Declaration that they were joint inventors of the “improvement in WALL PANEL WITH PREWIRED POWER SYSTEM described and claimed” in the first application. JX 1004, pp. 58-70. The application was issued on November 29, 1977, as Haworth’s ’294 patent. DX 1107, 1109, 1110; PX 324, 375, 425, 426, 429, 1039; JX 1001. This is the original Haworth patent on its pre-wired power system for panels. It is not in suit because on May 30, 1979, Ha-worth filed a patent application to reissue that patent under the provisions of the patent statute, 35 U.S.C. § 251. That application led to the Haworth ’733 reissue patent that is asserted in this litigation. By late 1975, Harold Wilson started to travel around the country visiting various local Code authorities, city inspectors and the like in important cites to determine whether the ERA 1 concepts would be acceptable. SF 40; Wilson Tr. at 121, 134. He concluded from those visits that they would be. Wilson’s visits further indicated to him that one of the February 1975 Ha-worth partial concepts might have some difficulty gaining the approval of local Code authorities because it incorporated a bendable strap in the central portion of the flexible electrical connector. Wilson Tr. at 134. That portion of the connector is exposed to potential impacts during use, such as from movement of mail carts, chairs, vacuum cleaners and the like. Bearing this in mind, Wilson decided it would be safer, in the first instance, to use a stiffer and harder structure for the central, hingeable portion of the flexible electrical connector which would stand a better chance of being accepted by the local Code authorities. It would be better, he concluded, to err on the side of using a more rugged design and high impact-resistance characteristics for the flexible connector. SF 41. The power blocks as originally designed by Haworth included a plug receptacle, or convenience electrical outlet, on each side, so each pre-wired panel would have four receptacles along its base, two on each side of the panel. Haworth later realized that it was not always advisable or necessary to have four receptacles for each pre-wired panel. A lesser number or none might be called for, for a particular panel or panels, in given work stations. Haworth made a design change in the power blocks and sold other versions thereof that had no receptacles on either side, or a receptacle on only one side. Haworth is still selling these versions of its power block with the ERA 1 panels. By around late 1976, Haworth was offering power blocks that each included one receptacle on each side, or only one on one side, or none on each side. Such power blocks were not installed until after Ha-worth received listing from Underwriters’ Laboratories (“UL”) in January, 1977. SF 47, 48; Wilson Tr. at 159-62. In connection with the early sales and commercial use of the ERA 1 panels, Wilson received information that the users wanted more electrical capacity than the three-wire, single circuit provided by ERA 1. This was because the majority of buildings in this country then had three phase 208/120 volt wiring systems that allowed the use of a five-wire, three circuit system. In early 1977, Wilson undertook the design of a five-wire, three circuit modification of ERA 1. Wilson developed it sufficiently so that patent application Serial No. 854,685 was filed thereon in the PTO by November 25, 1977. A continuation of that application, Serial No. 56,198, issued on March 22, 1983, as United States Patent No. 4,377,-724, entitled “Space Divider Wall Structure with Multiple Circuit Power System.” SF. 49. The earlier November 1977 Wilson patent application disclosed the advantages of a five-wire, three-circuit system adapted for the 208 volt, three-phase building power system while also being adaptable for use with the four-wire 220 volt single phase building power system. The Wilson patent application noted that multiple circuits increase the number of panels that can be effectively, electrically connected in series, thus permitting the panel wall structure to be used in much larger areas with fewer power inputs while, at the same time, providing sufficient receptacles. SF 50. Haworth had done design work and filed a patent application on a multiple circuit panel before Steelcase introduced its four wire, dual circuit panel in 1978. Westinghouse also introduced a two circuit panel system in 1978. Haworth introduced its five-wire, three-circuit improvement to ERA 1 at the June 1979 NEOCON show. It was called TRICIRCUIT. Then, at the June 1986 NEOCON show, Haworth introduced its eight-wire, three-circuit improvement, called THE POWER BASE. The Accused Products Like Haworth, Steelcase recognized the need for a flexible, pre-wired panel system in the early 1970’s. Among its early offerings was a “hard wired” panel system known as Movable Walls. While these panels passed code standards, they were inconvenient to rearrange because a licensed electrician had to be employed to remove and reassemble the power system. Richard Driscoll, a Steelcase engineer, was assigned the project of pre-wiring the Steelcase Movable Walls panels. Driscoll Tr. 2406-07; SF 54. The fundamental design work for that system was completely independent of the Haworth ERA 1 panels. The Steelcase Movable Walls pre-wired panel is disclosed in a Steelcase patent No. 4,135,775, naming Mr. Driscoll as the inventor. PX 10. The panels of the Driscoll invention were the first Steelcase pre-wired panels. The Driscoll invention was introduced at the June 1977 NEOCON show. It was made and sold commercially by Steel-case for about five years under the name Movable Walls. SF 55. A primary objective for the Driscoll invention was the provision of a horizontal power distribution system within the base of the two-inch Steelcase Movable Walls panel which would give maximum, functional flexibility with minimum modification to the present product line and be either factory or field installed. The system had to be listed by U.L. and also be in compliance with the National Electric Code, local electrical inspection codes and accepted by inspection authorities in metropolitan areas. SF 56. The electrical system designed by Driscoll used readily available electrical components. It had an outlet box at the base of the panel, having two conventional receptacles on each side at the bottom of the panel and a conventional BX cable (that includes a flexible metallic sheath around the wiring) for electrically connecting one panel to another. It used three wires providing a single circuit. The BX cable connector had conventional non-handed electrical connectors (so-called “Anderson connectors”) on each end for connecting to mating non-handed connectors at each end of the outlet box. The Driscoll power system contemplated having a licensed electrician hard-wire the panel pre-wiring to building power. Steelcase discontinued the commercial manufacture and sale of the Driscoll system in 1982, before Haworth’s ’008 patent issued in 1983. The Driscoll system is not accused of infringing the Haworth ’733 reissue patent. SF 58-59. After Steelcase saw the Haworth ERA 1 panels at the June 1976 NEOCON show it accelerated its efforts to design a pre-wired panel for its Series 9000 line. In August 1976, Steelcase formalized its efforts by a new project identified as Project No. P-219 to develop the Series 9000 load bearing panels including a pre-wired power system. PX 83; SF 60. The design and development work for the electrical distribution system for the Series 9000 panel was done mainly by Steelcase employees Robert Mohr, Harold VandenHoek and Larry Speet. SF 61. In January of 1976, Haworth fired Mr. VandenHoek, who had been Haworth’s Director of Engineering while the ERA 1 panels were being developed. Vanden-Hoek Tr. at 1182-84; R. Haworth Tr. at 1790-1792. While at Haworth, Vanden-Hoek had access to the design work which resulted in the ERA 1 system and to Ha-worth’s draft application for the '294 panel. Id. VandenHoek eventually found employment with Stow & Davis, another furniture company in the Grand Rapids area. VandenHoek Tr. at 1185. Stow & Davis was acquired by Steelcase in the 1980’s. SF 61. Steelcase interviewed VandenHoek again in August 1976 and thereafter hired him from Stow & Davis. Mr. VandenHoek started work on the Series 9000 panel system project P-219 in September 1976. Vanden-Hoek Tr. at 1192. He was placed in charge of that project. SF 61; VandenHoek Tr. at 1193-94, 1197. VandenHoek then sought to hire Harold Wilson. Wilson was contacted and interviewed by Steelcase personnel. Steelcase then offered Wilson a job. At first Wilson accepted, but later withdrew his acceptance. Defendant’s Exhibit (“DX”) 1127; Wilson Tr. at 1474. He elected to remain with Haworth, and he is still with them at this time. SF 62. There was no evidence that Steelcase attempted to obtain Haworth “trade secrets” from either VandenHoek or Wilson, nor was there any evidence indicating that either gentleman disclosed such secrets to Steelcase. Before Wilson was approached by Steel-case, Wilson interviewed Larry Speet, a prior work acquaintance of Wilson’s. Wilson needed a designer to assist him and he thought Speet was a good candidate. A meeting took place at Haworth. Wilson briefly referred Speet to the ERA 1 panels. After Wilson accepted Steelcase’s offer, he telephoned Speet and asked him if he would be interested in working with him at Steelcase. Speet said he was interested. During his interview with Steelcase personnel, Wilson had mentioned Speet’s name as a competent designer. After Wilson withdrew his acceptance of employment with Steelcase, VandenHoek interviewed Larry Speet. Speet was then hired by Steelcase in November, 1976. He was assigned to help design the electrical components for the new pre-wired panels for the Series 9000 line. Speet Tr. at 2181; SF 63. Speet worked with VandenHoek and Mohr on the Series 9000 panel project. During that time, and in the latter part of 1976, Speet saw literature at Steelcase on the Haworth ERA 1 pre-wired panel. Speet Tr. at 2183. By around June of 1977 he also saw a Haworth ERA 1 pre-wired panel at Steelcase. Speet Tr. at 2184-2188. The Haworth literature Speet saw was a Haworth brochure and the physical panel he saw was a Haworth ERA 1 small panel with full size electrical components. Speet looked at the Haworth ERA 1 brochure several times and examined it closely during the course of his design work on the pre-wired system for the Series 9000 panel. SF 65. Other Steelcase personnel analyzed the Haworth ERA 1 pre-wired panels from different technical and marketing aspects, including estimating the cost to make that panel. SF 66. The accused Steelcase Series 9000 panels utilize a plastic hinge strip for mechanically interconnecting panels so that two adjacent and interconnected panels may be pivoted relative to each other about the substantially vertical plastic hinge strip between the panels. That pivoting can occur while the flexible electrical connectors are in place. Steelcase’s Movable Walls and Valencia panels utilize different structures for mechanically connecting adjacent panels to one another, including metal brackets, instead of a plastic hinge strip. Steelcase designed the pre-wired power system for the Series 9000 so that it used specially-designed electrical components. Series 9000 was a four-wire system, and the convenience receptacles were removable. The four wires provide a second circuit, for lighting. SF 67-68. Steelcase introduced its four wire, two circuit Series 9000 panel at the NEOCON show in June of 1978. This panel was an addition to Steelcase’s existing line of Series 9000 furniture, which had been introduced in the early 1970’s and included desks, end panels, credenzas, spanner panels, and the like. Steelcase had always intended that structural load-bearing panels would be added to the Series 9000 line, and that they would be electrically powered. SF 70. In 1981, Steelcase introduced a five wire, three circuit version of the Series 9000 pre-wireable panel. The relevant features of the five wire system are in other respects the same as the 1978 four wire version of Series 9000. By 1982, Steelcase had replaced the pre-wired power system of the Driscoll invention for its Movable Walls with a modified version of the Series 9000 electrical components. The pre-wired power system of the Series 9000 was a more versatile system and more cost effective than the Driscoll invention. In October 1983, Steelcase introduced its Valencia brand pre-wireable panels, which utilize the Series 9000 type of electrical components. For all relevant purposes, the infringement issues for the Valencia panels as to the pre-wired power system are substantially the same as for Steelcase’s Series 9000 panels. Steelcase introduced an eight wire system (three circuits, plus a “dedicated” computer circuit) at the June 1985 NEO-CON show. With respect to the four patent claims asserted by Haworth, the infringement issues are substantially the same as with the earlier Series 9000 panels. The Series 9000 line of systems furniture of Steelcase is the top selling line among all of the Steelcase products. The accused Series 9000 panels are a very successful product. Steelcase's sales of the Series 9000 line would be reduced if it did not include an acceptable pre-wired panel. SF 72-77. With this background, the Court will analyze the three issues presented in the following order: (1) validity; (2) infringement; and (3) unenforceability. In general, the discussion will first address my conclusions of law on these issues and then make findings of fact particularly relevant to each issue. In summary form, my conclusions are as follows: (1) Steelcase failed to prove that either patent in suit is invalid for obviousness or for vagueness; (2) Haworth failed to prove that any of the asserted claims are infringed by the accused devices; and (3) Steelcase failed to prove that either patent is unenforceable for inequitable conduct. Any conclusion of law which may be considered in whole or in part as a finding of fact and any finding of fact which may be considered in whole or in part as a conclusion of law shall be so treated as if set for under the appropriate heading. Validity Steelcase argues that the patents in suit are invalid for basically two reasons. First, Steelcase argues that the patented devices are obvious in light of the prior art. Second, Steelcase argues that the patent claims at issue here are “too vague” to particularly point out and distinctly claim the invention. Standard Oil Co. v. American Cyanamid Co., 774 F.2d 448, 453 (Fed. Cir.1985); 35 U.S.C. §§ 112, 282(3). Conclusions of Law: Obviousness. 35 U.S.C. § 282 provides that, “A patent shall be presumed valid____ The burden of establishing invalidity of a patent or any claim thereof shall rest on the party asserting such invalidity.” As the Federal Circuit has held many times, “[T]he burden of proving invalidity [is imposed] on the attacker. That burden is constant and never changes and is to convince the court of invalidity by clear evidence.” American Hoist & Derrick Co. v. Sowa & Sons, 725 F.2d 1350, 1360 (Fed.Cir. 1984); Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1359 (Fed.Cir.1983). Therefore, Steelcase bears the burden to show invalidity by clear and convincing evidence. Alco Standard Corp. v. Tennessee Valley Authority, 808 F.2d 1490, 1498 (Fed.Cir.1986). The trial court is required under section 282 to “say only whether the patent challenger carried its burden of establishing invalidity.” Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1569 (Fed.Cir. 1987), cert. denied, — U.S.-, 107 S.Ct. 2187, 95 L.Ed.2d 843 (1987). The Federal Circuit has recognized that “when the prior art before the Court is the same as that before the PTO, the burden on the party of asserting invalidity is more difficult to meet.” Bausch & Lomb, Inc. v. Barnes-Hind, Hydrocurve Inc., 796 F.2d 443, 447 (Fed.Cir.1986); Hughes Aircraft, 717 F.2d at 1359. When the prior art relied on by the attacker adds nothing material to that considered by the Patent and Trademark Office (“PTO”) examiner, the attacker has the “added burden of overcoming the deference that is due to a qualified governmental agency presumed to have properly done its job,” since the PTO examiners are “presumed to have some expertise in interpreting the references and to be familiar from their work with the level of skill in the art,” and since it is their duty to issue only valid patents. American Hoist & Derrick, 725 F.2d at 1359. Moreover, where, as here, there was a contested, adversarial proceeding in which the defendant fully participated as a protestor, and the prior art evidence at trial was cumulative of the PTO proceedings, a lower court does not err in giving the PTO’s decision the deference that is due to a qualified governmental agency. Windsurfing International Inc. v. AMF Inc., 782 F.2d 995, 998-99 (Fed.Cir.1986), cert. denied, 477 U.S. 905, 106 S.Ct. 3275, 91 L.Ed.2d 565 (1986); Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1339 (Fed.Cir.1985). The Federal Circuit recently summarized the appropriate standards governing the obviousness inquiry in Uniroyal, Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044 (Fed. Cir.1988). In that case, the court held: Obviousness under 35 U.S.C. § 103 is a legal conclusion involving a preliminary determination of four factual inquiries: (1) the scope and content of the prior art; (2) the differences between the claims and the prior art; (3) the level of ordinary skill in the pertinent art; and (4) secondary considerations, if any, of non-obviousness. Secondary considerations include objective indicia of nonobviousness such as commercial success, long-felt but unresolved need and failure of others. The obviousness standard, while easy to expound, is sometimes difficult to apply. It requires the decisionmaker to return to the time the invention was made. “The invention must be viewed not with the blueprint drawn by the inventor, but in the state of the art that existed at the time____ That which may be made clear and thus ‘obvious’ to a court, with the invention fully diagrammed and aided ...” by experts in the field, “may have been a breakthrough of substantial dimension when first unveiled.” Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed.Cir.1985). “When prior art references require selective combination by the court to render obvious a subsequent invention, there must be some reason for the combination other than the hindsight gleaned from the invention itself.” Interconnect Planning Corp., 774 F.2d at 1143____ Something in the prior art as a whole must suggest the desirability, and thus the obviousness, of making the combination. Lindemann Maschinenfabrik Gmbh v. American Hoist & Derrick Co., 730 F.2d 1452, 1462 (Fed.Cir.1984). Uniroyal, 837 F.2d 1050-51. See also, Graham ¶. John Deere Co., 383 U.S. 1, 17, 86 S.Ct. 684, 693, 15 L.Ed.2d 545 (1966); Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561 (Fed.Cir.1987); Alco Standard Corp. v. Tennessee Valley Authority, 808 F.2d 1490, 1498 (Fed.Cir.1986); Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1538 (Fed.Cir.1983). 1. Level of Ordinary Skill in the Art. Several factors must be considered in determining the level of ordinary skill in the art. These include: (1) the educational level of the inventor; (2) the type of problems encountered in the prior art; (3) prior art solutions to those problems; (4) the rapidity with which innovations are made; (5) the sophistication of the technology; and (6) the educational level of active workers in the field. Environmental Designs, Ltd. v. Union Oil of California, 713 F.2d 693, 696-97 (Fed.Cir.1983); Orthopedic Equipment Co. v. All Orthopedic Appliances, Inc., 707 F.2d 1376, 1381-82 (Fed. Cir.1983). Persons devising panel pre-wiring in the mid 1970’s required no specialized training in pre-wiring of office divider panels. They would have needed some basic understanding of electrical and mechanical engineering, but would not have needed advanced training in either field. They needed to have only a basic understanding of general wiring and electrical component skills. In designing such a system, they would have studied commercially available products and literature, used the National Electric Code as a design guide, consulted with Underwriters Laboratories and other code personnel to insure that their designs would receive approval and then redesign their system accordingly until the distribution and safety problems were solved. Siegel Tr. 691-93; R. Haworth Tr. 1636-41; VandenHoek Tr. 1203-04, 1214-17; Speet Tr. 2224; Wilson Tr. 330-33, 349-50; Saylor Tr. 459-61; Mohr Tr. 2367-68. They would also have studied the then-current needs of the business community to determine the features which their system should possess in order to achieve market success. Siegal Tr. 691-94; Saylor Tr. 393-97; VandenHoek Tr. 1220-21. In the mid 1970’s several basic problems confronted office furniture manufacturers. With the acceptance of the open-office concept and the growing use of electric office appliances such as typewriters, computers and calculators, the need arose to develop a system for bringing power to many work stations arranged in a large, open office and to do so in such a manner that work stations could be rearranged quickly and inexpensively. Stipulated Facts 16, 20, 28. The National Electric Code and most local building codes also contained safety regulations which prohibited, among other things, the use of flexible cords. Stipulated Facts 16-19. Thus, there was a need to provide power to the work stations without using an abundance of extension cords in order to maintain proper safety standards. Finally, the use of extension cords and other temporary devices for power distribution was objectionable because they were unsightly and because they were often inconveniently underfoot for office personnel. Siegal Tr. at 695. The then-current solutions to these needs included “wire managers” or troughs to house extension cords and communication cables, floor monuments and power poles, outlet strips (which provided a flexible cord with a plug device at one end and a strip containing several convenience receptacles at the other) and hard-wired panel systems which contained wiring in the base of portable office panels that was permanently connected to the building’s power supply. Each of these solutions had certain drawbacks. Either they were inflexible and expensive to rearrange, as in the hard-wired systems and the power poles, or they represented temporary solutions which would not meet with Code approval, as in the wire managers and outlet strips. Stipulated Facts 19, 21-23, 25, 28. By the mid 1970’s, then, the office furniture industry as a whole recognized the need to develop a pre-wired portable office panel which would meet with Code approval and be susceptible to frequent rearrangement by the purchaser without the involvement of a licensed electrician. Ha-worth introduced its “ERA 1” panel system, embodying the inventions claimed in the original patent (U.S. Patent No. 4,060,-294) which led to both patents in suit, in June of 1976. Steelcase marketed the next innovation on the theme in June of 1978, also at NEOCON, when it introduced its “Series 9000” panel system, the earliest of the accused devices. Thereafter, innovations in pre-wired office panels were introduced into the market at intervals of between one and two years. Stipulated Facts 12-14. 2. Scope, Content and Distinguishing Features of the Prior Art. While each of the individual elements may have been suggested by the prior art, nothing in the prior art cited by Steelcase suggested the particular combination of elements disclosed in the Haworth patents. Nor can I see any reason on the record to combine the teachings of the various prior art references in order to render Haworth’s patents obvious. Environmental Designs, Ltd. v. Union Oil of California, 713 F.2d 693, 698 (Fed.Cir.1983). See also, Uniroyal Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1051 (Fed.Cir.1988); Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1143 (Fed.Cir.1985); Lindemann Maschinenfabrik Gmbh v. American Hoist and Derrick Co., 730 F.2d 1452, 1462 (Fed.Cir. 1984). The Corns patent (JX 303; U.S. Patent No. 3,362,005) teaches embedding a plurality of conductive wires in an insulating strip of nonconductive material, but does not teach the construction of an enclosed hinge device which will accommodate those conductive wires while concealing them from view. Zarley Tr. 2249-50, 2270. The Case patent, U.S. Patent No. 625,828; DX 1204, teaches the use of a flexible cord to electrically connect two railroad cars, which cord will accommodate relative movement between the cars. Case does not teach, however, the embedding of conductive wires in a hinge mechanism or the use of electrical connections of differing configurations at each end of the cord, so that the ends of the cord will mate with only one of the sockets placed on the cars. Nor does Corns involve a wall structure, portable or otherwise. Zarley Tr. 2247-49, 2267. These patents are thus distinguishable from the Haworth patents because Ha-worth teaches the use of a hinge mechanism to conceal conductive wires while permiting angular movement between adjacent panels. Haworth avoids the use of flexible cord to accomplish electrical connections between panels and involves a portable wall or panel system. I find, therefore, that neither Corns nor Case render the Haworth patents in suit obvious. Similarly, the Herbenar patent, U.S. Patent No. 3,590,135; DX 1207, is distinguishable from the Haworth patents. Herbenar disclosed, inter alia, an electrical distribution system for a suspended ceiling to facilitate the electrification of lighting elements which are suspended from that ceiling. Zarley Tr. at 2252. The invention involves the use of grid work above the suspended ceiling panels. Grid members are attached at either end to junction boxes which are attached to other grid members. Conductive wires run through the grid members, and these wires connect (via conventional plug and socket means) to the junction boxes. Zarley Tr. 2253-55. The junction boxes also feature a second set of openings to receive power cables from the lighting fixtures which will be suspended from the grid work. These openings are not identical to the openings intended to receive power cables from the grid members, although the openings intended to receive power cables from the grid members are identical on the various junction boxes. Zarley Tr. at 2255-56. The Herbenar patent does not render the Haworth patents in suit obvious for several reasons. First, it does not disclose the use of cooperating hinge parts which allow the various ceiling panels to be angularly adjusted relative to each other. Indeed, the ceiling panels disclosed in Herbenar are intended to remain stationary at all times, while the panels disclosed in the Haworth patents are intended to be portable and easily moved relative to one another. In addition, although the wires are enclosed within the Herbenar grid members, the grid members themselves are not enclosed within the ceiling panels. Zarley Tr. at 2274. In the Haworth disclosures, the raceways or channels containing the electrical wires are disposed interiorly of the various wall panels. The disclosure made in JX 1008, a brochure describing the Steelcase Movable Wall System, also does not render the patents in suit obvious. Steelcase’s Movable Wall System was a “hard wired” system, which utilized hinges to mechanically connect adjacent panels. Zarley Tr. at 2241; JX 1008. It provided channels at the bottom of each panel to accommodate electrical and communications wiring (in separate channels) which channels were contained within the side walls of the panels. Zarley Tr. at 2242. Duplex electrical outlets are located on each panel and each panel contains a junction box. Zarley Tr. at 2243. The channels conceal the wiring from view, and a special plate or “base cover” is provided to conceal wires at the junctures between the panels. Zarley Tr. 2246. The Haworth patents may be distinguished from the Steelcase Movable Wall disclosure because Haworth does not utilize “hard wiring” and wires are concealed from view at the junctures between panels by embedding them within the hinge mechanism, rather than by placing a separate plate over otherwise exposed wires. The disclosure made in the Siegal patent, U.S. Patent No. 3,841,042, JX 299, does not render the patents in suit obvious because Siegal teaches the use of flexible cords and conventional electrical components to accomplish handed electrical connections between adjacent panels. JX 299, fig. 8. Claims 5 and 29 of the '008 patent specify a non-handed connection. Siegal further discloses the use of a splined post and panels with corresponding ridges to accomplish the mechanical connections between panels. JX 299, figs. 2, 6. At the junctures between panels, the flexible cords are always partially visible. See, e.g., DX 1054; Siegal Tr. at 948-50. Claims 5 and 29 of the ’008 patent require that the electrical connector be integrally associated with, and substantially flush with the sides of the panel. The electrical connections utilized in Siegal are conventional, male and female plug and socket devices. JX 299; fig. 4. The raceways which contain the power distribution system are themselves “handed,” in the sense that power may flow through them in only one direction. Siegal Tr. at 1006-OS. In order to change the direction of the power flow, one must disconnect the raceways from the panels and reverse them. Siegal Tr. at 853-54. The convenience receptacles located on the exterior of each raceway are identical to the female socket means located inside the raceways. The Haworth patents may thus be distinguished from Siegal on many grounds. The Haworth system is non-handed. It does not employ flexible cord to accomplish electrical connections, nor does it make use of conventional plug and socket means in order to make those connections. The various electrical connection means are not identical, as they are in the Siegal system. See, claim 26 of the '733 patent. As claim 18 of the ’733 patent discloses, the Ha-worth inventions conceal wires at the junctures between panels by embedding them in a hinge device. In addition, Siegal does not incorporate or anticipate a power block comprising a box-like housing with four separate openings, two of which have different geometrical configurations. 3. Secondary Considerations. Steelcase argues that evidence of “secondary considerations bearing on obviousness” ought not be considered by this Court since Haworth has failed to demonstrate the required nexus between the allegedly infringed features of the Haworth inventions and the commercial success of the ERA 1 product. See, Stratoflex Inc. v. Aeroquip Corp., 713 F.2d 1530, 1539 (Fed. Cir.1983) (“A nexus is required between the merits of the claimed invention and the evidence offered, if that evidence is to be given substantial weight enroute to conclusion on the obviousness issue”). The principal “secondary considerations” which support findings of non-obviousness are: (1) whether the invention was commercially successful; (2) whether the invention represented a solution to a previously unsolved, but recognized problem in the industry; and (3) whether others had tried to devise a solution to that problem and failed. See, e.g., Aleo Standard Corp. v. Tennessee Valley Authority, 808 F.2d 1490, 1500 (Fed.Cir.1986); Rosemount, Inc. v. Beckman Instruments, Inc., 727 F.2d 1540, 1546 (Fed.Cir.1984); Stratoflex Inc. v. Aeroquip Corp., 713 F.2d at 1538-40. As the court indicated in Aleo Standard, “Prior art, however, cannot be evaluated in isolation, but must be considered in light of the secondary considerations bearing on obviousness.” 808 F.2d at 1499-1500. The point was more dramatically made in Stratoflex, where the court held, “It is jurisprudentially inappropriate to disregard any relevant evidence on any issue in any case, patent cases included. Thus evidence rising out of the so-called ‘secondary considerations’ must always when present be considered en route to a determination of obviousness.” 713 F.2d at 1538. Steelcase argues that Haworth failed to show that the commercial success of its ERA 1 product was attributable to the power system that is the subject of the patents in suit. While it may be true that other features of the panel system contributed to its commercial success, it cannot be doubted that Haworth’s introduction of a pre-wired, non-handed panel power distribution system also contributed to the success of the product. The other features of the Haworth panel, such as its accoustical properties and steel frame construction, had been present in other panels for quite some time. Haworth has demonstrated the proper nexus between the claimed invention and the secondary considerations it advances. Finally, I cannot accept Steelcase’s argument that the features which distinguish Haworth over the prior art devices cited were “obvious choices of design” rather than patentable innovations. Certainly, the need to develop a non-handed, pre-wired office panel was well-known in the industry at the time the Haworth invention was made. VandenHoek Tr. at 1250-54; Wilson Tr. at 508. However, this shows only that the problems were well understood in the office furniture industry. It does not show that anyone, including Steelcase, was able to devise an acceptable solution to those problems before the Haworth inventors did. Steelcase designed a panel system which incorporated, among other things, hinges to make the mechanical connections between panels. But it was unable to devise a method for pre-wiring those panels until after the Haworth invention was on the market. Much of the prior art cited by Steelcase predates its own Movable Wall System, yet that product was unable to avoid “hard wiring.” Siegal also provides evidence that the Haworth system was not obvious. Siegal testified that he attempted to solve the various problems noted by office furniture manufacturers in his Modulo 3 system, but he was unable to avoid the use of flexible cords or to devise a method for concealing those cords at the junctures between panels. Siegal Tr. at 694-95. In short, the long recognized need in the industry for a panel system similar to the one devised by Haworth, as well as the commercial success Haworth’s panel system had when it was introduced, SF 46, indicate to this Court that the invention, while it incorporated well-known design choices to solve problems long recognized in the industry, represented an innovation which no one, prior to the Haworth inventors, had been able to devise. Thus, I find that Steelcase has failed to prove by clear and convincing evidence that the innovations disclosed in the Haworth patents would have been obvious to one reasonably skilled in the art at the time the invention was made. I conclude, therefore, that the patents in suit are not rendered obvious by the prior art cited by Steelcase, and are thus not invalid. Conclusions of Law: Vagueness. Steelcase’s final argument for invalidity is that the claims in the patents in suit are too vague and prolix to distinctly define the invention claimed, and that they are invalid for that reason. I can find no basis in the record to substantiate this claim. While the claim language employed by Haworth is somewhat thick, it is no denser than the language in other patents cited to the Court. Compare JX 1002-1003 with PX 10, PX 291, JX 299. Certainly, Haworth might have employed more common diction in drafting its claims, and might have more carefully defined certain terms, such as "power block,” which are coined in the patent, but the fact that the drafting could have been better cannot, standing alone, invalidate an otherwise unobjectionable patent. I find, after reviewing the claim language employed by Haworth, that the claims are clear enough to meet the standards imposed by 35 U.S.C. § 112 and 35 U.S.C. § 282(3). A person reasonably skilled in the relevant arts of mechanical and electrical engineering could understand, from reviewing the claims and specifications, what matter is patented and what is not. See, Standard Oil, 774 F.2d at 453. Steelcase has failed to meet its burden to show by clear and convincing evidence that the patents in suit are invalid for the reason that they fail to distinctly define the invention claimed. Infringement Conclusions of Law. The applicable statutory provision for patent infringement, 35 U.S.C. § 271(a), provides: (a) * * * whoever without authority makes, uses or sells any patented invention, within the United States during the term of the patent therefore, infringes the patent. Noninfringement may be asserted as a defense. 35 U.S.C. § 282(1). The patent owner bears the burden of proving infringement by a simple “preponderance of the evidence.” SRI Int’l v. Matsushita Elec. Corp., 775 F.2d 1107, 1123 (Fed.Cir.1985). The patent order must show that the alleged infringer has “made, used, or sold” a device coming within the scope of the patent claims in suit. Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565, 1569 (Fed.Cir.1983); Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1361 (Fed.Cir.1983). Haworth therefore bears the burden of proof to establish infringement by a preponderance of the evidence. “The infringement inquiry is broken down into two steps: first, the scope of the claims must be ascertained and then the trier must decide whether the claims cover the accused device.” Palumbo v. Don-Joy Co., 762 F.2d 969, 974 (Fed.Cir.1985). The first is a question of law; the second is a question of fact. Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565, 1569 (Fed.Cir.1983). “Generally, particular limitations or embodiments appearing in the specification will not be read into the claims.” Hence, the asserted claims are not to be limited by reading into them the specific structure described in the specification and drawings of the patents in suit. Infringement is not determined by a comparison between parts of the description in a patent and the accused process or product or by a comparison between the patentee’s and the accused’s commercial products. It is determined by a comparison of the claimed invention and the accused product. Amstar Corp. v. Envirotech Corp., 730 F.2d 1476, 1481 (Fed.Cir.) cert. denied, 469 U.S. 924, 105 S.Ct. 306, 85 L.Ed.2d 240 (1984); Windsurfing International, Inc. v. AMF, Inc., 782 F.2d 995, 999 (Fed.Cir.) cert. denied, 477 U.S. 905, 106 S.Ct. 3275, 91 L.Ed.2d 565 (1986). A patent claim is interpreted in the light of its own language, the other claims, the prosecution history, the prior art, and particularly the patent specification, but not in light of the accused products themselves. SRI International v. Matshushita Electric Corp. of America, 775 F.2d 1107, 1118 (Fed.Cir.1985) (“SRI”). The determination of infringement normally involves an initial inquiry into whether the accused product literally corresponds to the precise language of the asserted patent claims. In order to establish literal infringement, every element of the claimed invention, or its substantial equivalent, must be present in the accused device. Lemelson v. United States, 752 F.2d 1538, 1551 (Fed.Cir.1985). If there is no literal infringement to the claim language, then the Court may consider whether or not to apply the doctrine of equivalents. Graver Tank and Mfg. Co. v. Linde Air Products Co., 339 U.S. 605, 607-08, 70 S.Ct. 854, 856, 94 L.Ed. 1097 (1950). The doctrine, however, if applied, may not be used to “erase a plethora of meaningful structural and functional limitations of the claim.” Perkin-Elmer Corp. v. Westinghouse Electric Corp., 822 F.2d 1528, 1532, 3 U.S.P.Q.2d 1321, 1324 (Fed.Cir.1987). Equivalence is not established simply by showing accomplishment of the same result, because results are abstractions which cannot be patented. Texas Instruments, Inc. v. U.S. Int’l Trade Comm., 805 F.2d 1558 (Fed.Cir. 1986) (“Texas Instruments”)-, Sealed Air Corp. v. U.S. Int’l Trade Comm., 645 F.2d 976, 985 (CCPA 1981) (“Sealed Air”). Rather, the proponent of infringement under this doctrine must show that the accused device “performs substantially the same function [as the disclosed invention] in substantially the same way to obtain the same result.” Graver Tank, at 608, 70 S.Ct. at 856. See also Datascope Corp. v. SMEC Inc., 776 F.2d 320, 325-26 (Fed.Cir. 1985); Atlas Powder Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 1579 (Fed. Cir.1984). Texas Instruments is one of the most recent Federal Circuit authorities on the doctrine of equivalents. In that case, the court first held that the patent at issue was a pioneer patent, but it then held that the patent was not infringed under the doctrine of equivalents. The court’s rationale is even more applicable here because the Ha-worth patents are not pioneers: While the prior art and prosecution history are necessary considerations in applying the doctrine of equivalents, they do not of themselves control the breadth of equivalents available under the doctrine. * * * The determination of equivalency by its nature is inimical to the basic precept of patent law that the claims are the measure of the grant. The doctrine of equivalents, ubiquitous since its origin ... exists solely for the equitable purpose of “preventing] an infringer from stealing the benefit of an invention.” Graver Tank, 339 U.S. at 608 [70 S.Ct. at 856]. To achieve this purpose, equivalency is judicially determined by reviewing the content of the patent, the prior art, and the accused device, and essentially redefining the scope of the claims. This constitutes a deviation from the need of the public to know the precise legal limits of patent protection without recourse to judicial ruling. For the occasional pioneering invention, devoid of significant prior art — as in the case before us — whose boundaries probe the policy behind the law, there are no immutable rules. We caution that the incentive to innovation that flows from “inventing around” an adversely held patent must be preserved. To the extent that the doctrine of equivalents represents an exception to the requirement that the claims define the metes and bounds of the patent protection, we harken to the wisdom of the Court in Graver Tank, that the purpose of the rule is “to temper unsparing logic” and thus to serve the greater interest of justice. Id. at 1572. The Federal Circuit thus affirmed the trial court’s finding of non-infringement. See also, Coleco Industries, Inc. v. United States Int’l Trade Comm., 573 F.2d 1247, 1258 (CCPA 1978) (“Coleco”); Precision Instrument Mfg. Co. v. Automotive Maintenance Machinery Co., 324 U.S. 806 at 814, 65 S.Ct. 993, 998, 89 L.Ed. 1381 (1945); Parmelee Pharmaceutical Co. v. Zink, 285 F.2d 465, 471 (8th Cir.1961) (Judge now Justice Blackmun) (“But the mere presence of equivalency is not in itself enough to warrant invocation of the doctrine nor does it necessarily equate with infringement.”) Under the “reverse doctrine of equivalents” there is no infringement when the accused products are “so far changed in principle” from the patent claims that they perform “a similar function in a substantially different way.” SRI, 775 F.2d at 1122-25. A patentee is estopped to rely on the doctrine of equivalents to make out a case of infringement when there is no literal infringement, if the patent claim in question was amended during prosecution to add limitations which narrowed the claim. “The doctrine of prosecution history estoppel precludes a patent owner from obtaining a claim construction that would resurrect subject matter surrendered during prosecution of his patent application.” Hughes, 717 F.2d at 1362; Mannesmann Demag Corp. v. Engineered Metal Products Co., 793 F.2d 1279, 1284-85 (Fed.Cir. 1986). The doctrine of equivalents will not be applied where the asserted range of the claims would then also encompass the prior art. When a patent is not pioneer, but merely improves or optimizes a class of matter in the prior art, the patent may not be used to prevent others from practicing other variations of the prior art. Sealed Air, 645 F.2d at 984, 985 (CCPA 1981) (the “patent ... discloses a process earlier performed ... [0]thers are entitled to practice variations of the old process”). The alleged infringer need not be practicing the prior art for the doctrine of equivalents to be barred. Texas Instruments, 805 F.2d at 1558. An applicant’s statements as found in the prosecution history, not only define the patent’s terms, but also set the barriers within which the claim’s meaning must be kept. Autogiro Co. of America v. United States, 384 F.2d 391, 399, 181 Ct.Cl. 55 (1967). A patentee having argued a narrow construction for his claims before the PTO is precluded from arguing a broader construction for the purposes of infringement Coleco, 573 F.2d at 1257; Seattle Box Co. v. Industrial Crating and Packaging Inc., 731 F.2d 818, 829 (Fed.Cir. 1984). The courts have refused to undertake the speculative inquiry as to whether such arguments were necessary. Kinzenbaw v. Deere and Co., 741 F.2d 383, 389 (Fed.Cir.1984) cert. denied, 470 U.S. 1004, 105 S.Ct. 1357, 84 L.Ed.2d 379 (1985); Prodyne Enterprises, Inc. v. Julie Pomer antz, Inc., 743 F.2d 1581, 1583 (Fed.Cir. 1984). A fundamental tenet of patent policy is that a patent is a teaching tool which others may use as a foundation for developing newer and better products, beneficial to the public. Indeed, a fundamental purpose of the claims is to precisely demarcate where others may or may not endeavor. General Electric Co. v. Wabash Appliance Corp., 304 U.S. 364, 369, 58 S.Ct. 899, 901, 82 L.Ed. 1402 (1938). Therefore, as the Federal Circuit has recently restated, the doctrine of equivalents cannot be utilized to block progress. “We caution that the incentive to innovation that flows from ‘inventing around’ an adversely held patent must be preserved.” Texas Instruments, 805 F.2d at 1572; State Industries, Inc. v. A.O. Smith Corp., 751 F.2d 1226, 1235-36 (Fed.Cir.1985). (“One of the benefits of a patent system is so-called ‘negative incentive’ to design around a competitor's products ...”). Haworth’s power block for the ERA 1 system is a boxlike housing which is located between the panel sides and wide enough to fill the space between them so as to be flush with them. JX 1041 A-B. It decoratively forms an integral part of the panel design. Wilson Tr. at 503. It has sets of openings or sockets to receive the plugs of the flexible connector. It also has other sets of openings or sockets establishing an obligatory convenience receptacle on each side of the panel. The Steelcase Series 9000 design avoids these features. JX 61. It uses instead a powerway accessory with flat, plate-like J-connectors at each end. PX 60A. The connectors are hidden from view in use, and are