Full opinion text
MEMORANDUM OPINION AND ORDER REGARDING DEFENDANT’S MOTION FOR SUMMARY JUDGMENT OF PATENT INVALIDITY AND PLAINTIFF’S MOTION FOR SUMMARY JUDGMENT AND TO DISMISS FOR LACK OF CONTROVERSY BENNETT, District Judge. TABLE OF CONTENTS I. INTRODUCTION.946 A. Procedural Background.946 B. Factual Background.949 1. The ’166 'patent.949 2. The ’21p0 and ReU82 patents.950 8. The ’851 patent.951 L The ParenP-Automatic-Dethmers triangle.953 5. Facts relevant to false advertising and false marking claims.955 II. LEGAL ANALYSIS.955 A. The ’851 Patent............955 1. Subject matter jurisdiction.........955 a. The parties’contentions............955 b. Subject matter jurisdiction in patent cases..........956 c. Subject matter jurisdiction here..........957 i. Explicit threat and reasonable apprehension.........957 ii. Present activity of the alleged infringer........960 2. Summary.................960 B. The’166 Patent Revisited..........961 1. Contentions of the parties ..............961 2. Prosecution history estoppel.............961 a. The nature of prosecution history estoppel.........962 b. The Warner-Jenkinson presumption....................964 3. Prosecution histo'ry estoppel here................966 a. Prosecution histoi'y..................966 b. Presumption and rebuttal ...............971 C. False Advertising...............973 1. Which circuit’s law applies? ....................974 2. Summary judgment standards...................974 3. Elements of this “false advertising” claim...........975 A The record evidence..............978 a. The “patented flex joint” representation................978 i. Falsity............979 ii. Injury....................980 b. The infringement representations...............982 D. False Marking..................982 III. CONCLUSION.............984 In ruling on the parties’ first round of dispositive motions, the court found that the “devil was in the details” in granting summary judgment of invalidity of one of the plaintiffs patents in suit, declining to grant summary judgment of non-infringement of the defendant’s patent in suit, and in ruling on various challenges to other patent and non-patent claims. See Dethmers Mfg. Co., Inc. v. Automatic Equip. Mfg. Co., 23 F.Supp.2d 974 (N.D.Iowa 1998). Details appear just as likely to bedevil the second round of dispositive motions in this case, as the court is called upon to consider the invalidity of yet another of the plaintiffs patents, reconsider “equivalents” infringement of the defendant’s patent in suit in light of recent decisions of the Federal Circuit Court of Appeals on prosecution history estoppel, and address a new set of challenges to various other claims. I. INTRODUCTION A. Procedural Background The parties to this lawsuit are both makers of tow bars used to tow an automobile behind a recreational vehicle (R.V.) and the patents in suit relate to such tow bars. Plaintiff Dethmers Manufacturing Company, Inc., filed this action on June 26, 1996, seeking primarily a declaratory judgment, pursuant to 28 U.S.C. §§ 2201 and 2202, of non-infringement of a pátent owned by defendant Automatic Equipment Manufacturing Company and declaratory, injunc-tive, and damages relief for Automatic’s alleged infringement of one of Dethmers’s patents. More specifically, in Count I of its second supplemental amended complaint, filed on November 20, 1997, Dethmers sought declaratory judgment that the tow bars Dethmers manufactures do not infringe one of Automatic’s patents, United States Patent No. 5,356,166 (the ’166 patent or the Automatic patent), that the ’166 patent is invalid and unenforceable, and that Automatic is without right or authority to threaten or to maintain suit against Deth-mers for alleged infringement of the ’166 patent. Count II sought damages for, as well as injunctive and declaratory relief from, infringement by Automatic of Deth-mers’s own patent, United States Patent No. Re32,482 (the Re482 patent or the Dethmers reissue patent), which is a reissue of United States Patent No. 5,232,240 (the ’240 patent or the Johnson patent), a patent Dethmers alleges it acquired from the successors in interest to the inventor, Andrew B.' Johnson of Barton, North Dakota. Count III sought compensatory and punitive damages and injunctive relief for Automatic’s alleged breach of a contract with Dethmers, as the assignee of Richard A. Parent, not to produce products incorporating the “Parent Invention” without permission or payment of consideration. Count IV sought compensatory and punitive damages and injunctive relief for “statutory” misappropriation by Automatic of a trade secret, the “Parent Invention.” Count V was a comparable “common-law” claim of misappropriation of a trade secret, also seeking compensatory and punitive damages and injunctive relief. Count VI alleged conversion of the “Parent Invention” and sought compensatory and punitive damages and injunctive relief. Count VII alleged misappropriation of the “intellectual property” of Dethmers, again identified as the “Parent Invention,” and sought compensatory and punitive damages and injunctive relief. Finally, Count VIII alleged unjust enrichment by Automatic as the result of its use of design concepts of the “Parent Invention” in its products, and sought compensatory and punitive damages and injunctive relief. On December 5, 1997, instead of answering the second supplemental amended complaint, Automatic filed the first of the dispositive motions ruled upon in the court’s prior decision, a motion to dismiss or in the alternative for partial summary judgment, for more definite statement, and to strike. On March 11, 1998, Automatic filed a motion for summary judgment on the invalidity of the Dethmers reissue patent, the Re482 patent. On June 2, 1998, Dethmers took the offensive with its own motion for summary judgment or, in the alternative partial summary judgment, asserting that it was entitled to summary judgment that it is not liable for infringing Automatic’s ’166 patent on grounds of invalidity and unenforceability of the patent itself, and non-infringement of the patent by Dethmers’s tow bars. In its order of September 29, 1998, on the parties’ first round of dispositive motions, the court ruled as follows: 1. Automatic’s December 5, 1997, motion to dismiss or in the alternative for partial summary judgment, for more definite statement, and to strike is granted as to summary judgment on all prayers for punitive damages on state-law claims, but otherwise denied. 2. Automatic’s March 11, 1998, motion for summary judgment on the invalidity of the Re482 patent is denied as to insufficiency of “errors,” and assertion that the reissue patent is not for the “same invention” as the original ’240 patent, but granted as to the inadequacy of the reissue declaration, on the ground that it does not comply with the detail required by the decisions of the Federal Circuit Court of Appeals in Nupla [Corp. v. IXL Mfg. Co., Inc., 114 F.3d 191 (Fed.Cir.1997),] and [In re] Constant, [827 F.2d 728 (Fed.Cir.1987), cert. denied, 484 U.S. 894, 108 S.Ct. 251, 98 L.Ed.2d 209 (1987),] and the former version of 37 C.F.R. § 1.175, and the Re482 patent is hereby declared invalid. 3. Dethmers June 2,1998, motion for summary judgment or in the alternative partial summary judgment on patent invalidity, unenforceability, and non-infringement is denied in its entirety. Dethmers Mfg. Co., Inc., 23 F.Supp.2d at 1044. The court subsequently denied Dethmers’ motion to reconsider, but certified its ruling on the first set of dispositive motions for interlocutory appeal pursuant to 28 U.S.C. § 1292(b). Dethmers Mfg. Co., Inc. v. Automatic Equip. Mfg. Co., No. C 96-4061-MWB, Order on Motion to Reconsider or in the Alternative to Certify for Interlocutory Appeal (Nov. 4, 1998). No notice of such an interlocutory appeal was ever filed in this case, however. Following the court’s ruling on the first set of dispositive motions, Automatic answered the second supplemental amended complaint. In that Answer, filed on October 14, 1998, in addition to denials and affirmative defenses, Automatic also asserted several counterclaims. In Count I of its counterclaims, Automatic seeks declaratory judgment that Dethmers’s original ’240 patent and its Re482 patent are invalid, unenforceable, and not infringed by Automatic’s products. In Count II, a “false advertising” claim under the Lan-ham Act, Automatic asserts that Dethmers has violated 15 U.S.C. § 1125(a) by falsely asserting that its tow bar contains a “patented flex joint” and falsely asserting that Automatic is infringing Dethmers’s patent rights. Automatic seeks injunctive relief on this count. In Count III, Automatic accuses Dethmers of “false marking” in violation of 35 U.S.C. § 292 and seeks imposition of an appropriate fine under the statute, as well as an award of one-half of the fine to Automatic pursuant to § 292(b). In Count IV of its counterclaim, Automatic asserts that Dethmers is infringing Automatic’s ’166 patent and seeks appropriate declaratory, injunctive, and damages relief. Finally, in Count V of its counterclaim, Automatic seeks declaratory judgment of non-infringement, invalidity, and unen-forceability of Dethmers’s United States Patent No. 5,765,851 (the Parent patent or the ’851 patent). Dethmers filed its reply to Automatic’s counterclaims on November 6,1998. On March 10, 1999, Dethmers filed its Third Amended and Substituted Complaint. This amended complaint reasserted all counts of the Second Supplemental and Amended Complaint, as detailed above, but added that the claims in Counts III through VIII were governed by Nebraska law, in light of this court’s ruling on the first set of dispositive motions so holding. In addition, this latest amended complaint added two new counts, Counts IX and X, which assert promissory estoppel and quantum meruit, respectively, relating to the “Parent invention.” Automatic answered the Third Amended and Substituted Complaint on March 19, 1999, denying Dethmers’s new claims and reiterating Automatic’s denials, defenses, and counterclaims as stated in answer to Dethmers’s second supplemental amended complaint, as detailed above. Dethmers filed its reply to the renewed counterclaims on April 1,1999. The present round of dispositive motions began on June 15, 1999, when defendant Automatic filed its Motion for Summary Judgment of Invalidity of U.S. Patent No. 5,765,851. Automatic asserts that the ’851 patent is invalid for failure to comply with 35 U.S.C. § 102(b), because the invention was “on sale” and in “public use” more than one year prior to the filing date of the application for the ’851 patent. On June 16, 1999, Dethmers filed its Motion for Summary Judgment and to Dismiss for Lack of Controversy, asserting that there is no present controversy between Automatic and Dethmers regarding the ’851 patent, that Dethmers is entitled to summary judgment on Automatic’s “false advertising” claim under 15 U.S.C. § 1125(a) and “false marking” claim under 35 U.S.C. § 292, and that Dethmers is entitled to summary judgment on both its claim of non-infringement and Automatic’s claim of infringement of the ’166 patent, on the ground that Automatic’s claim of infringement is barred by prosecution history es-toppel. This last contention revisits grounds raised in the prior round of dis-positive motions, but which this court declined to resolve in light of genuiné issues of material fact. Briefs, resistances, and replies have now been filed on the present dispositive motions and the court heard oral arguments on August 26, 1999. Plaintiff Dethmers Manufacturing Company, Inc., was represented at the oral arguments by David Tank of Davis, Brown, Koehn, Shors & Roberts, P.C., in Des Moines, Iowa, and Michael Gilchrist and Brian J. Laurenzo of Dorsey & Whitney, LLP, also in Des Moines, Iowa. Defendant Automatic Equipment Manufacturing Company was represented at the oral arguments by Donald R. Schoonover of Fremont Hills, Missouri, and by Tim Engler of Harding, Shultz & Downs in Lincoln, Nebraska. The briefing in this case was of exceptional quality and the record evidence was well documented. Furthermore, although the issues involved are clearly very contentious, the oral arguments were not only excellent, but were conducted with the utmost civility. Because trial‘in this matter is currently set to begin on October 18, 1999, the court has moved with speed, but not with haste, to provide as prompt a ruling on the present motions as due consideration of the merits would permit. B. Factual Background The court will discuss here only the nucleus of facts pertinent to the present motions for summary judgment, partial summary judgment, or to dismiss. In its legal analysis, the court will address, where necessary, the parties’ arguments concerning the correct treatment of factual allegations or their assertions of genuine issues of material fact, which the parties contend are dispositive of the motions now before the court. As mentioned above, and discussed in greater detail in this court’s ruling on the prior round of dispositive motions, see Dethmers Mfg. Co., Inc., 23 F.Supp.2d at 983-98, both parties make tow bars, based on their respective patents, for towing an automobile behind a recreational vehicle. A comparatively brief reprise of the nature of the patents discussed in more detail in the court’s prior ruling (Automatic’s ’166 patent and Dethmers’s ’240 and Re482 patents) is appropriate here, as is a slightly more detañed discussion of the patent newly introduced into this litigation by Automatic’s counterclaims, the Dethmers ’851 patent. However, it is the history surrounding the application for and issuance of the ’851 patent and the timing of Automatic’s production of allegedly infringing products that is of primary interest here, rather than the question of whether any of Automatic’s products hterahy or equivalently infringes the ’851 patent. Thus, even for this patent, the discussion here will not consider the nature of the invention in as exhaustive detaü as the court gave the patents at issue in the prior round of dispositive motions. 1. The ’166 patent Automatic’s 166 patent, which issued on October 18, 1994, is for an “Arrestably Lockable Telescoping Tow-Bar Assembly.” The Abstract of the patent describes the invention as follows: An improved locking mechanism for an arrestably lockable telescoping tow bar assembly comprises a slidable latch member surrounding balls-containing sideward openings of an outer tube that are radially alignable with an outside groove of a telescopingly associated inner tube, the slidable latch member including a medial cam portion slidably surrounding the outer tube between a surrounding retainer ring augmentation therefor and the balls-containing side-ward openings therefor; a cover slidably surrounding a trailward part of the slid-able latch member and being traüwardly immovable along the outer tube; and a helical spring means actuatably extending between the cover member and the slidable latch member. Patent No. ’166, p. I. In other words, in the invention described in this patent, the inner tube of the telescoping assembly is locked in place when the “balls” align with the “outside groove” on the inner tube and the balls are pushed down into the groove by the “cam portion,” which is in turn pushed into the locking position by the “helical spring.” The claimed invention consists of five claims, only the first of which is “independent,” and all the rest of which are “dependent” upon claim 1. As interpreted in pertinent part by the court in its prior ruling, the ’166 patent is for a locking mechanism for a tow bar arm that involves the following: a groove “circularly surrounding” the inner of two telescoping tubes, that is, a single continuous groove describing a complete circle around the inner tube, Dethmers Mfg. Co., Inc., 23 F.Supp.2d at 1037; a “cam portion” that is a sliding piece that converts linear motion along the longitudinal axis of the telescoping arms of the tow bar into linear motion in a perpendicular direction, ie., “radially” inward and outward from the- longitudinal axis of the inner tube, to push the locking balls or members into locking position in the groove, Id. at 1039; and a helical spring means between a cover member and the slidable latch member medially-located cam portion that pushes the cam portion into the locking position. Id. The court concluded in its prior ruling that Dethmers’s tow bars do not literally infringe these limitations, because they have at least two grooves that together define no more than a 240-degree arc of a circle around the inner tube, see id. at 1037, and the helical spring on the Deth-mers tow bar is not “between” the “cam” and any “cover,” but between the “cam” and a part that is not a “cover,” but instead a part between the “cam” and the inner tube; ie., there is no “cover” in the Dethmers tow bar apart from the “cam” itself. See id. at 1039. The court concluded that summary judgment was not appropriate on the question of infringement under the doctrine of equivalents — although the court was of the opinion that comparable parts of the Dethmers tow bar locking mechanism performed the same function, in the same way, with the same result— because of genuine issues of material fact concerning prosecution history estoppel. See id. at 1038 & 1039-40. Dethmers asks the court to revisit the question of whether the applicability of prosecution history es-toppel is ripe for determination in the present round of dispositive motions. 2. The ’240 and Re482 patents Although not directly at issue in the present motions for summary judgment, the Dethmers ’240 and Re482 patents are nonetheless pertinent to Dethmers’s summary judgment motion concerning Automatic’s “false advertising” and “false marking” counterclaims. As noted in this court’s prior ruling, see id. at 988-93, the ’240 patent is for a “Towing Hitch” involving both a “pivot block,” which allowed the hitch to pivot vertically and horizontally, as well as to swivel about an axis parallel to the ground, and a pair of folda-ble tow arms that could be locked in either the folded or extended positions. Only the first of the three claims of this patent, the claim including a frame, pivot block, and tow arms, is “independent”; the two additional claims, stating a means for locking the pivot block in storage position, and defining the pivotal connection of the pivot block to the forward portion of the tow hitch, respectively, are “dependent” upon the first claim. The Re482 patent is a reissue of the ’240 patent, issued on March 25, 1997, after Dethmers acquired the ’240 patent from the successors in interest to the original inventor, Andrew B. Johnson of Barton, North Dakota, Johnson’s wife and brother. In the Re482 patent, portions of claim 1 of the ’240 patent were deleted, as was any reference in new claim 1 to “arms.” The language of claims 2 and 3 of the ’240 patent was not altered in any way, although those claims were made dependent upon a different, independent claim 1 in the Re482 patent; that is, they are now dependent on a claim with no pivot arms. New claims 4 through 10 were added to the reissue patent. However, the new claims, inter alia, reintroduce the pivot arms formerly part of claim 1 as independent claims. See id. at 991-93. In its prior ruling, the court invalidated the Re482 patent for failure to comply with the detail required for a reissue declaration. See id. at 1022-26. 3. The ’851 patent The patent newly introduced into the litigation by Automatic’s counterclaims is United States Patent No. 5,765,851 (the ’851 patent or the Parent patent), a patent for a “Self-Aligning Towing Apparatus.” It incorporates elements of the invention referred to in the court’s prior decision as the “Parent invention.” See, e.g., Dethmers Mfg. Co., Inc., 23 F.Supp.2d at 993-94. The patent shows that it is a continuation of Ser. No. 285,224, for which application was made on August 3, 1994, but which was later abandoned. Application for the patent was subsequently made on February 21, 1996, and the patent issued on June 16, 1998. The inventor is shown as Richard A. Parent and Dethmers is shown as the assignee. For the present purposes, it will suffice to repeat the description of the invention in the abstract of the patent, and to include the first five figures illustrating the invention. The abstract states the following: A storable self-aligning towing assembly which allows universal pivoting about three axes between a towing vehicle and a towed vehicle. The towing assembly is self-supporting. A hitching member is releasably attached to a towing vehicle at a first end of the hitching member; a first yoke member is pivotally attached to a second end of the hitching member such that the first yoke member pivots about a first axis which is generally horizontal and is normal [sic] an extended longitudinal axis of the hitching member; a second yoke member is connected to the first yoke member such that the second yoke member is free to rotate with respect to the first yoke member about an axis that is generally parallel to an extended longitudinal axis of the hitching member; a towed vehicle attachment means is releasably attached at a first end to a towed vehicle; the towed vehicle attachment means is piv-otally attached to the second yoke member such that the second yoke member pivots with respect to the towed vehicle attachment means about a second axis which is generally vertical and is normal to the extended longitudinal axis of the hitching member. The configuration allows the towing assembly to pivot from a towing position to a storage position on the rear of the towing vehicle. A latching mechanism secures the self-aligning towing assembly in the storage position on the rear of the towing vehicle. The self-aligning towing assembly may be further converted into a shipping position. United States Patent No. 5,765,851, Exhibit H, Plaintiffs Statement of Uncontested Facts in Support of Its Motion for Summary Judgment or in the Alternative Partial Summary Adjudication (Patent No. ’851), p. 1. The invention is illustrated in the patent as follows: 4. The Parent-Automatic-Dethmers triangle The parties still agree that the figure who stands at the nexus between Automatic’s and Dethmers’s development of new generation tow bars is Richard Parent, although they now appear to assert more far-reaching factual disputes concerning Parent’s relationship with each company and his impact on the development of each company’s new generation tow bars. Again, the court will not attempt here to resolve — or even identify — all of the factual disputes concerning Parent’s involvement with the litigants, only to provide a context for the legal analysis to follow. It is undisputed that, on about February 28, 1993, in Pomona, California, Parent approached William A. Bachman, an engineer employed by Automatic, with sketches he had made of a new type of tow bar that involved a swivel or universal joint and folding tow bar arms. The tow bar could also be folded up on the back of an R.V. for storage when not in use. These ideas are referred to herein as the “Parent invention.” Parent apparently hoped that Bachman would bring his invention to the attention of Automatic’s management and that some kind of agreement for manufacturing such a tow bar could be worked out. The parties dispute whether the plan envisioned by Parent and/or Bachman was for some kind of “joint” development and production or a “licensing” of Parent’s design. The parties apparently do not dispute that Parent left it to Bachman to decide whether he would show Parent’s design ideas to Jay Hesse, Automatic’s President, but that Parent requested that Bachman keep Parent’s ideas confidential if he decided not to pursue them. However, no written confidentiality or other agreement came out of Parent’s meeting with Bachman. Hesse later declined to sign a non-disclosure letter Parent sent him in May of 1993. Parent did not actually give Bachman his drawings at the time of the meeting in Pomona, although he sent Bachman copies of his drawings on or about March 5,1993. Back in Pender, Nebraska, in Automatic’s R & D shop, Bachman, working from his memory of Parent’s invention, combined some of Parent’s ideas with an idea he and another Automatic engineer had been exploring for telescoping tow bar arms to produce a prototype tow bar, which was shown to Hesse on or about March 4 or 5, 1993. On July 20,1993, Automatic notified Parent that a prototype tow bar embodying his swivel joint would be sent to Blacksburg, Virginia, for trials on the mo-torhome of Ivan Mullenix, an independent sales representative for Automatic. That prototype was installed on Mullenix’s mo-torhome, with Parent present, on August 6, 1993, but Parent and Dethmers assert that the prototype did not embody all of Parent’s ideas and that Parent in fact objected to the development of a prototype in the absence of a licensing agreement for his ideas. Automatic eventually marketed a tow bar based on the prototype tried by Ivan Mullenix as its AVENTA brand in 1994, but Automatic and Parent never came to an agreement on rights to or licensing of Parent’s ideas. The parties dispute the extent to which Bachman’s prototypes or the AVENTA tow bar actually incorporated Parent’s invention. Parent and Automatic were never able to reach a final agreement for joint production, assignment of rights, or licensing of a tow bar including the “Parent invention.” Parent subsequently approached a Deth-mers employee with his design ideas at a recreational vehicle show in the spring of 1994. Dethmers was interested in Parent’s invention, but first initiated a patent search. That search turned up the Johnson ’240 patent. After Dethmers had obtained the rights to the ’240 patent, it concluded negotiations with Parent by entering into a “Patent Assignment-Royalty Agreement.” Dethmers then began prosecuting the Parent ’851 patent as Parent’s assignee, as well as prosecuting a reissue of the Johnson ’240 patent. In support of Petitions to Make Special filed in the prosecution of both the Re482 patent and ’851 patent, Dethmers asserted that prompt processing of its applications was required, because of concerns that Automatic was manufacturing a product that would infringe the claims of the patents. The original ’240 patent was eventually reissued as the Re482 patent on March 25, 1997, and the Parent patent was eventually issued as the ’851 patent on June 16, 1998. About six months prior to issuance of the ’851 patent, Automatic stopped producing the AVENTA tow bar. However, Automatic contends that, because of the long life of its tow bars, it will continue to repair AVENTA tow bars at least through the period the ’851 patent provides protection and that some of those repairs may rise to the level of infringing “re-manufacturing” or “reconstruction.” Dethmers produced its own tow bar with a swivel joint and telescoping arms, rather than square folding arms as shown in the Johnson and Parent patents, during 1995. Dethmers apparently does not dispute that it developed telescoping arms by attempting to “design around” Automatic’s ’166 patent. Dethmers’s tow bars were originally marketed under the brand name “KAR-BAR,” but were later marketed under the brand name “EXCALI-BAR.” 5. Facts relevant to false advertising and false marking claims Although Automatic’s “false advertising” and “false marking” claims do not involve infringement, they nonetheless involve the ’240 patent. Dethmers contends that its executives believed that the ’240 patent covered the EXCALI-BAR tow bars, and thus advertised its EXCALI-BAR as featuring a “patented flex joint.” The EXCA-LI-BAR bore a mark indicating that it was covered by the ’240 patent, and after the Re482 patent was applied for, also bore a mark indicating that the tow bars were made with a patent pending. Deth-mers’s tow bars were advertised in magazines and brochures distributed by dealers or at trade shows. Automatic also alleges that one or more of Dethmers’s sales representatives told customers that Automatic was infringing Dethmers’s patents, that Automatic would not be able to “design around” Dethmers’s patents, and that consequently Automatic would soon be out of the tow bar business. II. LEGAL ANALYSIS In its legal analysis, the court will address first the cross-motions for summary judgment or to dismiss concerning the ’851 patent. The court will then turn to Deth-mers’s motion for summary judgment on both its claim of non-infringement and Automatic’s counterclaim of infringement of the ’166 patent, then finally to Dethmers’s motion for summary judgment on Automatic’s “false advertising” and “false marking” counterclaims. A. The ’851 Patent Although Automatic was the first to move for summary judgment concerning the ’851 patent — seeking summary judgment on Count V of its counterclaim, which alleges that the ’851 patent is invalid under the “on sale” and “public use” bars of 35 U.S.C. § 102(b) — the court must first take up the portion of Dethmers’s motion which seeks to dismiss Automatic’s counterclaim concerning this patent, because Deth-mers’s motion contests the court’s subject matter jurisdiction to hear the pertinent counterclaim at all. If the counterclaim is not properly before the court, of course, the court will not reach Automatic’s assertions of patent invalidity. 1. Subject matter jurisdiction a. The parties’ contentions In its June 16, 1999, Motion for Summary Judgment and to Dismiss for Lack of Controversy, Dethmers contends that the court should dismiss Automatic’s counterclaim for declaratory judgment concerning the ’851 patent, because there is no explicit threat of action by Dethmers and no present activity by Automatic that could constitute infringement. More specifically, Dethmers contends that there is no explicit threat of action by Dethmers indicating an intent to enforce patent rights, even though, Dethmers filed a statement with the United States Patent and Trademark Office (the PTO) in prosecuting the Parent patent in which Dethmers asserted that Automatic was infringing the claims of the patent application. Dethmers points out that at the time the statement was filed, Automatic was making and selling the AVENTA tow bars, which clearly did fall within the scope of the pending application. However, two things subsequently happened: (1) at least six months before the Parent patent was actually issued, Automatic ceased making the AVENTA tow bar; and (2) the claims of the patent application were amended after the statement was made, limiting its applicability only to the AVENTA tow bar of Automatic’s products. Dethmers suggests that it might have been attempting to enter into licensing negotiations with Automatic, and such negotiations cannot give rise to a litigation controversy until the negotiations break down. Dethmers also contends that its pursuit of non-patent claims concerning the Parent invention does not support an actual controversy concerning the Parent patent, because the trade secrets of the Parent invention were broader than the claims actually allowed in the Parent patent. Automatic counters, however, that there are “explicit threats” sufficient to establish an actual controversy, because of Dethmers’s actions during prosecution of the Parent patent, Dethmers’s present allegations against Automatic, and a threatening letter to Automatic from an attorney representing Parent. Furthermore, Automatic contends that, since 1994, Deth-mers’s sales personnel have made comments to customers that Dethmers was going to stop Automatic from making and offering towing products and accessories. Turning to the second prong of the inquiry, Dethmers contends that there is no present activity by Automatic that could constitute infringement, because Automatic is no longer making the AVENTA tow bar. Dethmers contends that the Parent patent requires that the pivots of the tow bar be in the order vertical, swivel, horizontal, as ordered from the towing R.V. to the towed vehicle, and that only Automatic’s AVENTA tow bar has ever had the pivots in that order. In short, Dethmers contends that Automatic is not currently engaged in making any products that infringe the ’851 patent. Automatic argues, however, that it is or may be engaged in potentially infringing activity, because from time to time it repairs AVENTA tow bars, and such repairs may rise to the level of “re-manufacturing” that constitutes infringement. Automatic also argues that its customers’ continued “use” of AVEN-TA tow bars, which are rugged and long-lived products, may also constitute infringement under 35 U.S.C. § 271, resulting in possible claims back against Automatic by customers Dethmers may charge with infringing its patents. b. Subject matter jurisdiction in patent cases The Federal Circuit Court of Appeals recently reiterated the standards for determining the court’s subject matter jurisdiction over a declaratory judgment action concerning infringement, enforceability, or validity of a patent, such as Count V of Automatic’s counterclaim concerning the ’851 patent: Under the Declaratory Judgment Act, 28 U.S.C. § 2201(a) (1994), a district court has jurisdiction over a declaratory judgment action only when there is an “actual controversy.” “Whether an actual controversy exists upon particular facts is a question of law, and is subject to plenary appellate review.” BP Chems. Ltd. v. Union Carbide Corp., 4 F.3d 975, 978, 28 USPQ2d 1124, 1127 (Fed.Cir.1993). For an actual controversy to exist, “[tjhere must be both (1) an explicit threat or other action by the patentee, which creates a reasonable apprehension on the part of the declaratory plaintiff that it will face an infringement suit, and (2) present activity which could constitute infringement or concrete steps taken with the intent to conduct such activity.” Id. at 978, 4 F.3d 975, 28 USPQ2d at 1126. Amana Refrigeration, Inc. v. Quadlux, Inc., 172 F.3d 852, 855 (Fed.Cir.1999); Hunter Douglas, Inc. v. Harmonic Design, Inc., 153 F.3d 1318, 1326 (Fed.Cir.1998) (same two-step inquiry), cert. denied, — U.S. -, 119 S.Ct. 1037, 143 L.Ed.2d 45 (1999); Fina Research, S.A. v. Baroid Ltd., 141 F.3d 1479, 1481 (Fed.Cir.1998) (same two-step inquiry). “In this inquiry, the ‘first prong looks at the [pat-entholder’s] conduct; [the] second to that of [the declaratory judgment] plaintiff.’ ” Hunter Douglas, Inc., 153 F.3d at 1326 (quoting Arrowhead Indus. Water, Inc. v. Ecolochem, Inc., 846 F.2d 731, 736 (Fed.Cir.1988)). Furthermore, “ ‘[a]n actual controversy must be extant at all stages of review, not merely at the time the complaint is filed.’ ” Quadlux, Inc., 172 F.3d at 855 (quoting Preiser v. Newkirk, 422 U.S. 395, 401, 95 S.Ct. 2330, 45 L.Ed.2d 272 (1975)). The court will explore the requirements of each prong of the inquiry in more detail in its application of the test below. c. Subject matter jurisdiction here i. Explicit threat and reasonable apprehension. On the first prong of the “actual controversy” inquiry, it is not just the patentholder’s conduct that matters, but the effect of that conduct upon the alleged infringer, because this prong requires “‘an explicit threat or other action by the patentee, which creates a reasonable apprehension on the part of the declaratory plaintiff that it will face an infringement suit.’” Hunter Douglas, Inc., 153 F.3d at 1326 (quoting Cygnus Therapeutics Sys. v. ALZA Corp., 92 F.3d 1153, 1159 (Fed.Cir.1996), with emphasis added by the Hunter Douglas court). Thus, this prong is sometimes referred to as the “reasonable apprehension” inquiry. See, e.g., id. at 1327. Nevertheless, as to the patentholder’s conduct, the Federal Circuit Court of Appeals “ha[s] consistently required that, for a district court to exercise jurisdiction over a declaratory judgment action in which the plaintiff complains of noninfringement, invalidity, or unenforceability, the plaintiff must allege ‘acts of defendant indicating an intent to enforce its patent.’ ” Id. (quoting Arrowhead, 846 F.2d at 737). in other words, “for an actual controversy more is required than the existence of an adversely held patent.” BP Chems., 4 F.3d at 978, 28 U.S.P.Q.2d at 1126. We have maintained this requirement, for it “protects quiescent patent owners against unwarranted litigation” under Title 35. Arrowhead, 846 F.2d at 736, 6 U.S.P.Q.2d at 1689. The “reasonable apprehension” prong of the two-part test thus contributes to policing the boundary between a constitutional controversy, which is judicially cognizable under the Declaratory Judgment Act, and “a difference or dispute of a hypothetical or abstract character,” Aetna, 300 U.S. at 240, 57 S.Ct. 461, which is not. Accordingly, because the allegations do not support a reasonable apprehension on Hunter Douglas’s part, there is no actual controversy. Hunter Douglas, Inc., 153 F.3d at 1326-27. In Quadlux, there was no actual controversy extant at the time of appellate review of the declaratory judgment claim— even though an actual controversy had previously existed — because, prior to appellate review, Quadlux had entered into a covenant not to assert a patent infringement claim against Amana, removing any reasonable apprehension that Amana would face an infringement suit based on its activities before the date the covenant was filed. Quadlux, Inc., 172 F.3d at 855. The Federal Circuit Court of Appeals held further that the declaratory plaintiff could not assert reasonable apprehension of being sued with regard to products “in the pipeline,” but not advertised, manufactured, marketed, or sold before the filing date, because “an actual controversy cannot be based on a fear of litigation over future products.” Id. Similarly, in Hunter Douglas, the court found that the declaratory action had been properly dismissed, because “Hunter Douglas did not allege that the Defendants have signaled an intention, in any way, to file suit claiming infringement of the Harmonic patents by Hunter Douglas’s future product.” Hunter Douglas, Inc., 153 F.3d at 1326. Furthermore, threats before a patent issues are of no moment, because the Federal Circuit Court of Appeals has held “that a threat is not sufficient to create a case or controversy unless it is made with respect to a patent that has issued before a complaint is filed.” GAF Building Materials Corp. v. Elk Corp. of Dallas, 90 F.3d 479, 482 (Fed.Cir.1996) (holding that the district court correctly dismissed the case for lack of a justiciable controversy where the patent in question had not issued at the time the declaratory judgment complaint was filed, and subsequent issuance of the patent did not cure the defect, because the alleged infringer failed to seek leave to amend the pleadings). In contrast, in Dainippon Screen Manufacturing, the Federal Circuit Court of Appeals found sufficient evidence of “threats” by the patentholder to satisfy this prong of the inquiry. See Dainippon Screen Mfg. Co., Ltd., 142 F.3d at 1273. In that case, there had been a meeting between representatives of the alleged in-fringer, Dainippon, and the patentholder, CFMT, both makers of semiconductors, at which Dainippon presented information relating to its apparatus and indicated an intention to display the apparatus at a trade show. Id. at 1268. After Dainip-pon’s presentation, representatives of CFMT “asserted that there was an ‘infringement problem.’ ” Id. Further, Shortly thereafter, Heinrich Parker, outside counsel for both CFM and CFMT, telephoned Roderick Thompson, Dainippon’s outside counsel, in San Francisco and left a message which stated in relevant part: We believe that we’ve got good, strong, multiple patents in this field. I have been told that [Dainippon] has known about them for years. We are a well-funded/capitalized company and we intend to protect our rights.... We do not think your client should be proceeding unilaterally to show at this show and if they do of course we’re going to have to consider how we will handle that. We will not be afraid to protect our rights. Thompson’s Transcription of Parker’s Voice Mail Message, June 23, 1995. Parker thereafter reiterated that his clients would not agree to refrain from suing Dainippon and that Dainippon would exhibit the FL-820L “at its peril.” Dainippon did not display the FL-820L at SEMICON West. Dainippon Screen Mfg. Co., Ltd., 142 F.3d at 1268. During the course of further licensing negotiations between Dainippon and CFMT, CFMT initiated infringement actions against other competitors over the same patent in question between Dainip-pon and CFMT. Id. When licensing negotiations failed, Dainippon brought a declaratory judgment action. Id. In light of these facts, the Federal Circuit Court of Appeals found that the district court properly exercised subject matter jurisdiction over the declaratory judgment action. See id. at 1273. Here, none of the alleged “threats” by Dethmers is sufficient to create in Automatic a “reasonable apprehension” of being sued for infringement of the ’851 patent. Quadlux, Inc., 172 F.3d at 855; Hunter Douglas, Inc., 153 F.3d at 1326. First, nothing in the application and prosecution of the ’851 patent constitutes the requisite threat, because “a threat is not sufficient to create a case or controversy unless it is made with respect to a patent that has issued before a complaint is filed.” GAF Building Materials Corp., 90 F.3d at 482. Although the ’851 patent issued before Automatic filed its declaratory judgment claim, the statements upon which Automatic relies as creating its “reasonable apprehension” were made prior to issuance of the patent — that is, the “threats” were not made with respect to a patent that had issued. Cf. id. Just as “an actual controversy [requires] more ... than the existence of an adversely held patent,” Hunter Douglas, Inc., 153 F.3d at 1326-27 (quoting BP Chems., 4 F.3d at 978), this court believes an actual controversy requires more than statements made in support of an application for the patent in question. Furthermore, there is nothing in Deth-mers’s conduct since the ’851 patent issued that “signaled an intention, in any way, to file suit claiming infringement of the [’851 patent] by [Automatic’s] product.” Hunter Douglas, Inc., 153 F.3d at 1326. Although Automatic makes much of Deth-mers’s prosecution of non-patent claims related to the Parent invention in this litigation, those claims clearly do not relate to infringement of the ’851 patent, but to Automatic’s allegedly wrongful acquisition of Parent’s trade secrets, which were broader than the patent ultimately issued. The first prong of the “actual controversy” inquiry for a patent claim is not satisfied by threats of litigation of any kind between the parties, but by threats creating “a reasonable apprehension on the part of the declaratory plaintiff that it will face an infringement suit.’ ” Id. (quoting Cygnus Therapeutics Sys., 92 F.3d at 1159) (emphasis added); accord Quadlux, Inc., 172 F.3d at 855. Dethmers has studiously avoided asserting that any current product made by Automatic infringes the ’851 patent; indeed, Dethmers has repeatedly maintained in this litigation that the only product made by Automatic that could have infringed the ’851 patent, the AVEN-TA tow bar, is no longer in production. Although Automatic asserts that Deth-mers’s non-patent claims are an attempt to obtain patent-like protection three years or more prior to issuance of the patent, Automatic’s argument seeks to strip away all trade secret protection — common-law and statutory — prior to issuance of a patent, as well as excuse overreaching or trickery in negotiations concerning use or licensing of unpatented inventions. Patent law preemption clearly does not reach so far. Automatic also points to evidence, in the form of testimony of Jay Hesse, that Deth-mers’s representatives have told Automatic’s customers that Automatic will be put out of business by this litigation. However, even according to Hesse’s testimony, such comments occurred from about 1994 until about July of 1996, before the ’851 patent was issued, and thus cannot constitute á threat to pursue an action for infringement of the ’851 patent. Cf. GAF Building Materials Corp., 90 F.3d at 482. Furthermore, these comments to customers do not resemble the explicit warnings of intention and ability to enforce patent rights made to the alleged infringer found in Dainippon Screen Mfg. Co., Ltd., 142 F.3d at 1268. Finally, Automatic relies on a “threatening” letter from Parent’s Canadian attorney, App. IV, Tab 6. That letter, dated March 11, 1994, from Douglas B. Thompson, states that “I cannot help but feel that Mr. Parent was duped into signing the documents [executed by Parent and Bach-man disclosing an invention for a self-aligning tow bar with a swivel joint invented by Parent in combination with a locking mechanism invented by Bachman] without fully appreciating their legal significance,” and that “[w]e will communicate with you further when Mr. Parent’s patent issues.” However, the first “threat,” or reference to misconduct by Automatic does not suggest a claim for infringement, but a claim of overreaching or trickery. As to the reference to the forthcoming Parent patent, this evidence again suffers from the defect that it is a threat that antedates issuance of the patent by some four years, GAF Building Materials Corp., 90 F.3d at 482, and it is not from the assignee of the patent as issued, such that it does not constitute conduct of the patentholder indicating any basis for a present apprehension of an infringement suit. Hunter Douglas, Inc., 153 F.3d at 1326 (the first prong requires “an explicit threat or other action by the patentee”). Thus, Automatic has failed to satisfy the first prong of the inquiry concerning subject matter jurisdiction over its declaratory judgment counterclaim regarding the ’851 patent. ii. Present activity of the alleged in-fringer. Even supposing that Automatic had satisfied the first prong of the “actual controversy” inquiry, it has not satisfied the second — the prong considering whether there is “present activity [of the alleged infringer] which could constitute infringement or concrete steps taken with the intent to conduct such activity.” Quadlux, Inc., 172 F.3d at 855. Dethmers contends that Automatic is not currently engaged in making any products that infringe the ’851 patent. Automatic contends, however, that it is or may be engaged in potentially infringing activity, because from time to time it repairs AVENTA tow bars, and such repairs may rise to the level of “re-manufacturing” or “reconstruction” that constitutes infringement. Automatic also argues that its customers’ continued “use” of AVENTA tow bars, which are rugged and long-lived products, may also constitute infringement, resulting in possible claims back against Automatic by customers Dethmers may charge with infringing Dethmers’s patents.' As to this prong of the inquiry, the Federal Circuit Court of Appeals has explained, “The residual possibility of a future infringement suit based on [the alleged infringer’s] future acts is simply too speculative a basis for jurisdiction over [the alleged infringer’s] counterclaim for declaratory judgments of invalidity.” Super Sack Mfg. Corp. v. Chase Packaging Corp., 57 F.3d 1054, 1060 (Fed.Cir.1995), cert. denied, 516 U.S. 1093, 116 S.Ct. 815, 133 L.Ed.2d 760 (1996); cf. Quadlux, Inc., 172 F.3d at 855 (“an actual controversy cannot be based on a fear of litigation over future products”). Thus, speculation that Automatic might repair AVENTA tow bars and that such repairs might rise to the level of infringing “re-manufacturing” or “reconstruction” simply is “too speculative a basis for jurisdiction over [Automatic’s] counterclaim for declaratory judgmen[t] of invalidity.” Id. Likewise, Automatic’s assertions that it might reintroduce the AVENTA tow bar into the market in the future are insufficient for two reasons: First, under Quadlux, 172 F.3d at 855, a declaratory plaintiff cannot assert a reasonable apprehension of being sued with regard to products “in the pipeline,” but not yet advertised, manufactured, marketed, or sold, because “an actual controversy cannot be based on a fear of litigation over future products”; and, second, Automatic has presented no evidence of any “ ‘concrete steps taken with the intent to conduct such activity,’ ” see id. (quoting BP Chems. Ltd., 4 F.3d at 978, for this alternative for the second prong of the actual controversy inquiry). Finally, an assertion that Automatic’s customers might be the target of “use” infringement suits and Automatic might then be subject to claims from its customers is also entirely speculative. Cf. Quadlux, Inc., 172 F.3d at 855; Super Sack Mfg. Corp., 57 F.3d at 1060. The record includes no evidence that Dethmers is contemplating or pursuing such “use” infringement suits. Indeed, at oral arguments, counsel for Deth-mers represented that Dethmers would not be instituting such suits against Automatic’s customers. Thus, Automatic has also failed to satisfy the second prong of the “actual controversy” inquiry, such that this court does not have subject matter jurisdiction over Automatic’s declaratory judgment counterclaim regarding the ’851 patent. 2. Summary The court concludes that it does not have subject matter jurisdiction over Count V of Automatic’s counterclaim concerning non-infringement, unenforceability, and invalidity of the ’851 patent, because Automatic has failed to establish either prong of the “actual controversy” requirement for such a claim. Quadlux, Inc., 172 F.3d at 855. There is no actual controversy extant at this time. See id. Thus, Dethmers’s motion to dismiss Automatic’s counterclaim regarding the ’851 patent must be granted. Because the court does not have subject matter jurisdiction over Automatic’s counterclaim, the court cannot properly reach Automatic’s motion for summary judgment asserting that the ’851 patent is invalid under 35 U.S.C. § 102(b), because the invention was “on sale” and in “public use” more than one year prior to the filing date of the application for the ’851 patent. Consequently, Automatic’s motion for summary judgment will be denied for lack of subject matter jurisdiction and Count V of Automatic’s counterclaim will be dismissed. B. The T66 Patent Revisited The court turns next to Dethmers’s request that the court revisit its conclusions, found in its ruling on the first round of dispositive motions, that genuine issues of material fact preclude summary judgment as to “equivalents” infringement by Deth-mers of Automatic’s T66 patent. See Dethmers, 23 F.Supp.2d at 1038 & 1039-40. In its June 16, 1999, motion for summary judgment, Dethmers argues that it is entitled to summary judgment on both its claim of non-infringement and Automatic’s claim of infringement of the ’166 patent on the ground that Automatic’s claim of infringement is barred by prosecution history estoppel in light of recent decisions of the Federal Circuit Court of Appeals. 1. Contentions of the parties Although this court previously found genuine issues of material fact as to the applicability of prosecution history estop-pel to “equivalents” infringement of the “groove” and “spring location” limitations of the ’166 patent, Dethmers points to more recent decisions of the Federal Circuit Court of Appeals “clarifying” that whether prosecution history estoppel applies is a question of law. Dethmers contends that the record on prosecution history estoppel is complete and that there is no reason to ask the jury to make any factual determinations, because Automatic has no chance of satisfying the legal requirements for overcoming prosecution history estoppel. Somewhat more specifically, Dethmers contends that Automatic amended its patent claims in a manner that responded to rejection of the claim based on prior art, and thus prosecution history estoppel applies. In the alternative, Dethmers argues that Automatic has failed to overcome the “Warner-Jenkinson presumption” that Automatic made the amendments in question in response to prior art rejection, and thus prosecution history estoppel applies. Automatic argues that prosecution history estoppel is not applicable to the particular amendments in question, because neither amendment was made in response to prior art, but only voluntarily to clarify the claims of the T66 patent. 2. Prosecution history estoppel Even prior to the decisions upon which Dethmers relies, it was clear that the applicability of prosecution history estoppel is a question of law, and this court’s prior ruling finding underlying genuine issues of material fact concerning the reasons for the amendments in question suggested nothing different. Rather, even on this question of law, the record before the court at the time a party raises the issue may not be sufficiently well developed to permit the necessary legal determinations, because the determination must be made in light of the prosecution history and the totality of the circumstances. See, e.g., Loral Fairchild Corp. v. Sony Corp., 181 F.3d 1313, 1327 (Fed.Cir.1999). Similarly, because the applicability of prosecution history estoppel in this case depends upon underlying facts, only if this court finds that the record is now sufficiently well developed will the court be able to answer the question of law of the applicability of prosecution history estoppel; Dethmers’s mere assertion of the issue does not force the court to make that determination at this time. a. The nature of prosecution history estoppel Prosecution history estoppel, as the Federal Circuit Court of Appeals recently explained, is a limitation on the scope of infringement under the “doctrine of equivalents”: In Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997), the Supreme Court endorsed the continued vitality of the doctrine of equivalents. Because the doctrine of equivalents “has taken on a life of its own, unbounded by the patent claims,” the Court held that the doctrine must be applied as an objective inquiry on an element-by-element basis. Id. at 28-29, 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146. More importantly to this case, the Court affirmed that prosecution history estoppel continues to be a defense to infringement. Id. at 40, 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146 (“Prosecution history estoppel continues to be available as a defense to infringement ... ”). The touchstone of prosecution history estoppel is that a patentee is unable to reclaim through the doctrine of equivalents what was surrendered or disclaimed in order to obtain the patent. Warner-Jenkinson, 520 U.S. at 30, 117 S.Ct. 1040; see also Cybor Corp. v. FAS Tech. Inc., 138 F.3d 1448, 1460, 46 USPQ2d 1169, 1178 (Fed.Cir.1998) (in banc); Hughes Aircraft Co. v. United States, 140 F.3d 1470, 1476, 46 USPQ2d 1285, 1290 (Fed.Cir.1998); Litton Systems, Inc. v. Honeywell, Inc., 140 F.3d 1449, 1456, 46 USPQ2d 1321, 1325 (Fed.Cir.1998); Pall Corp. v. Micron Separations, Inc., 66 F.3d 1211, 1219, 36 USPQ2d 1225, 1231 (Fed.Cir.1995), cert. denied, 520 U.S. 1115, 117 S.Ct. 1243, 137 L.Ed.2d 326 (1997). Prosecution history estoppel applies to matter surrendered as a result of amendments to overcome patentability rejections, see Warner-Jenkinson, 520 U.S. at 30-31, 117 S.Ct. 1040; Cybor, 138 F.3d at 1460, 46 USPQ2d at 1178, and as a result of argument to secure allowance of a claim. See, e.g., Wang Lab., Inc. v. Mitsubishi Elec., Inc., 103 F.3d 1571, 1578, 41 USPQ2d 1263, 1269 (Fed.Cir.1997); Hoganas AB v. Dresser Indus., Inc., 9 F.3d 948, 952, 28 USPQ2d 1936, 1939 (Fed.Cir.1993); Texas Instruments Inc. v. United States Int’l Trade Comm’n, 988 F.2d 1165, 1174-75, 26 USPQ2d 1018, 1025 (Fed.Cir.1993). Loral Fairchild Corp. v. Sony Corp., 181 F.3d 1313, 1322 (Fed.Cir.1999) (emphasis added); Pall Corp. v. Hemasure, Inc., 181 F.3d 1305, 1310 (Fed.Cir.1999) (“Prosecution history estoppel bars a patentee from imposing liability for infringement by an otherwise equivalent device or method, when the claim scope that would have reached the accused device or method was relinquished by the patentee in order to avoid the prior ait.”); Augustine Med., Inc. v. Gaymar Indus., Inc., 181 F.3d 1291, 1297-98 (Fed.Cir.1999) (prosecution history estoppel, like the “all elements” rule, is a limitation on undue expansion of the doctrine of equivalents that “prevents a patentee from recapturing subject matter surrendered during prosecution of the patent”); Sextant Avionique, S.A. v. Analog Devices, Inc., 172 F.3d 817, 826 (Fed.Cir.1999); Pharmacia & Upjohn Co. v. Mylan Pharmaceuticals, Inc., 170 F.3d 1373, 1376 (Fed.Cir.1999). As noted above, “[pjrosecution history estoppel is a legal question subject to de novo review on appeal.” Id. at 1323; Pall Corp., 181 F.3d at 1311; Augustine Med., Inc., 181 F.3d at 1297-98. Prosecution history estoppel arises from amendments that were required to be made for reasons of “patentability.” Warner-Jenkinson, 520 U.S. at 30-31, 117 S.Ct. 1040; Loral Fairchild Corp., 181 F.3d at 1321. The Federal Circuit Court of Appeals has concluded that the meaning of the word “patentability,” from its context in Warner-Jenkinson, means “patentability over prior art.” Bai v. L & L Wings, Inc., 160 F.3d 1350, 1355 (Fed.Cir.1998). However, the specific question of whether amendments related to “patentability” is limited to those amendments made to overcome prior art under §§ 102 and 103, or any reason affecting the issuance of a patent, is now before the Federal Circuit Court of Appeals for en banc determination. See Festo Corp., 187 F.3d at 1381-82. For now, this court will follow the narrower construction of “patentability” adopted by a panel of the Federal Circuit Court of Appeals in Bai, that is, that “pat-entability” means “patentability over prior art.” See Bai, 160 F.3d at 1355; accord Pall Corp., 181 F.3d at 1310-11 (“Prosecution history estoppel bars a patentee from imposing liability for infringement by an otherwise equivalent device or method, when the claim scope that would have reached the accused device or method was relinquished by the patentee in order to avoid the prior art.”) (emphasis added). In addition to arising from surrender of subject matter as a result of amendments to overcome patentability rejections, and as a result of argument to secure allowance of a claim, see Loral Fairchild Corp., 181 F.3d at 1321, prosecution history es-toppel is generated when a claim limitation is added in order to overcome a specific reference by the submission of new claims containing the limitation. Pall Corp., 181 F.3d at 1311; see also Pharmacia & Upjohn Co., 170 F.3d at 1376-77 (identifying some of the activities giving rise to prosecution history estoppel, and citing cases). Furthermore, “[f]or an estoppel to apply, the assertions in favor of patentability must ‘evince a clear and unmistakable surrender of subject matter,’ ... not an ‘equivocal’ one.” Pharmacia & Upjohn Co., 170 F.3d at 1377 (citations omitted). As to determining the scope of the es-toppel, prior art may be of some aid, although it is not dispositive, but the ultimate test is an objective one: “whether a competitor would reasonably conclude that an applicant’s prosecution conduct had surrendered the disputed subject matter.” Augustine Med., Inc., 181 F.3d at 1298-99 (citing Cybor, 138 F.3d at 1457); Sextant Avionique, S.A., 172 F.3d at 826-27 (“The scope of estoppel, ie., what subject matter has been surrendered during prosecution by the patentee, is to be viewed from the vantage point of a reasonable competitor of the patentee, .... and is determined with reference to the prior art and any ame