The United States District Court for the Western District of Oklahoma granted *1372 summary judgment of noninfringement to Weatherford International, Inc. (Weather-ford). Frank’s Casing Crew & Rental Tools, Inc. v. Weatherford Int’l, Inc., No. CIV-01-104-F (W.D.Okla. May 28, 2003). The district court determined that Weath-erford’s StabMaster, a remotely controlled casing stabbing device mounted in a derrick, does not infringe Frank’s Casing Crew & Rental Tools, Inc.’s (Frank’s) U.S. Patent No. 5,049,020 (the ’020 patent). Because the district court correctly decided that the “meаns for selectively pivoting” clause must necessarily include a lift plate located under the boom (not present in the StabMaster), this court affirms.
I.
The ’020 patent, entitled “Device for Positioning and Stabbing Casing from a Remote Selectively Variable Location,” claims a system for handling (i.e., “positioning and stabbing”) sections of well casing suspended within a derrick during oil field operations. ’020 patent, col. 1, 11. 19-30. Well casing lines a well bore to facilitate removal of oil or gas. During completion of a well, the derrick suspends sections of casing from a pulley, known as a crown block, and then lowers the section for connection to another casing section already in the well bore. Id. at col. 8, 11. 38-44. The test of engineering skill is to align and connect the sections properly. Id. at col. 2, 11. 3-11. Because the sections of casing may be up to thirty-six inches in diameter and weigh 300 pounds per foot, manual alignment is difficult and poses a risk of injury. Id. at col. 6, 11. 8-9; col. 7, 11. 24-25; col. 18, 11. 29-34. The ’020 patent addresses these problems with a remotely controlled device for aligning the casing sections.
The ’020 patent’s stabbing apparatus is less bulky than prior art devices. Thus, the ’020 system mounts the apparatus on the derrick without interfering with other operations. Id. at col. 5, 1. 62 — col. 6, 1. 3. The ’020 patent teaches that the invention has “at least three major interconnectable subassemblies which can be easily taken apart to facilitate transport, storage and operative mounting of the entire apparatus at a selected location in a drilling derrick and above the floor of the derrick.” Id. at col. 7, 11. 1-5. Additionally, the invention has an “extendable boom which carries jaws at one end for engaging the casing, and which is hydraulically movable in an up-and-down pivoting motion or in a side-to-side motion, or both such motions simultaneously.” Id. at col. 7,11. 28-33.
The claimed stabbing apparatus thus raises and lowers the boom holding the casing section. The preferred embodiment for performing this function includes a hydraulic piston and cylinder subassem-bly 96, which is connected to the boom through a plate structure mаde up of a diagonal boom plate 116, a forwardly extending boom plate 118, and a lateral lift plate 120, 1 which are shown in Figures 2 and 3, reproduced below. Id. at col. 11,11. 5-18.
*1373 [[Image here]]
*1374 [[Image here]]
When not in use, an operator may lift the stabbing apparatus up out of the way by activating the boom. Frank’s asserted claims 6, 7, and 8 against Weatherford, each of which involves pivoting the boom up and down but does not require yawing (side-to-side movement).
Claim 6, for instance, states: 2
6. A system for making up a vertically extending string of interconnected casing sections comprising:
a derrick ...
a derrick bracket subassembly detach-ably connected to a side of said derrick; a boom and jaw subassembly detachably connected to said derrick bracket subas-sembly, and including:
means for selectively pivoting said boom about said horizontal axis to raise and lower the second end of said boom which carries said jaws, and to elevate said boom to a location where it extends in a generally vertical direction;
a remote control assembly detachably connected to said boom and jaw subas-sembly ...
Id. at col. 22,1. 20 — col. 23,1. 39 (emphasis added). While none of the foregoing claims requires yawing, other claims of the ’020 patent do include such a limitation. Id. at col. 18,11. 60-64 (claim 1); col. 19, 11. 42-43 (claim 2); col. 20, 11. 45-51 (claim 3); col. 22,11.13-19 (claim 5).
The parties presented the trial court two limitations for claim construction: “means for selectively pivoting said boom about said horizontal axis to raise and lower the second end of said boom which carries said jaws, and to elevate said boom to a location where it extends in a generally vertical direction” and “detachably.” Frank’s Casing Crew & Rental Tools, Inc. v. Weatherford Int'l Inc., No. CIV-01-104-F, slip. *1375 op. at 2-8 (W.D.Okla. July 22, 2002). The parties and the district court agreed that the “means for selectively pivoting” limitation is in means-plus-function format, governed by 35 U.S.C. § 112, ¶ 6. The parties also agreed on the function of the means-plus-function limitation, namely “selectively pivoting said boom about said horizontal axis to raise and lower the second end of said boom which carries said jaws, and to elevate said boom to a location where it extends in a generally vertical direction.” ’020 patent, col. 22,11. 61-66. The parties disputed, however, the structure corresponding to the claimed function disclosed in the specification. For Frank’s, the corresponding structure is the piston and cylinder subassembly; for Weather-ford, the structure includes the lift and boom plates disclosed in the preferred embodiment of the invention. The district court agreed with Weatherford:
[The “means for selectively pivoting”] must necessarily include a lift plate located under the boom. The boom rests on the lift plate, and the boom is not connected to the lift plate. The boom moves back-and-forth across the lift plate. The boom is raised and lowered by a piston and cylinder that operate against the lift plate, and not directly against the boom.
Frank’s Casing Crew, No. CIV-01-104-F, slip. op. at 14 (W.D.Okla. July 22, 2002). Frank’s disagrees, arguing the district court improperly imported structure unnecessary to рerform the recited function of pivoting the boom about the horizontal axis. Instead, as noted, Frank’s asserts that the relevant corresponding structure is the piston and cylinder subassembly.
In reaching its interpretation, the district court also examined the prosecution history of the ’020 patent. Id. The ’020 patent is a continuation of Application Ser. No. 203,252, which issued as Patent No. 4,921,386 (the ’386 patent). During prosecution of thе ’386 patent, the examiner required the applicant to distinguish the invention from the casing handling device described in U.S. Patent No. 3,840,128 issued to Swoboda, Jr. et al. (Swoboda). The Swoboda device used a cylinder attached and under the boom for the lifting function. To distinguish the Swoboda device, the applicant noted that its position compromises its use: “[a lifting cylinder,] located directly below the boom and directly connected thereto, [that includes] a yawing piston and cylinder subassembly which extends at an acute angle to the longitudinal axis of the boom, and is attached at one end to a different part of the boom and jaw subassembly, and can cause the boom to cant or swing from side-to-side, simply cannot be used.” May 19, 1989 Amendment in response to March 3, 1989 PTO action in Application No. 203,252, at 41 (emphasis in original) (Amendment). In other words, a lifting cylinder direсtly connected to and located below the boom cannot be used with the ’020 patent. The applicant also argued that the “spatial and positioning limitation” in Swoboda “is overcome in the present invention by connecting the [cylinder which lifts the boom] not directly to the boom, but by connecting it indirectly to the boom through securement” to the lifting plate. Id. (emphasis in original).
With respect to the claim term “detach-ably,” Frank’s would give the word no special meaning, but read it to include no limitation involving the ease of detaehability. Conversely, Weatherford argued “de-tachably” should be limited to parts that can be easily and quickly taken apart or disconnected. The district court ruled “detachably” “means that the component or subassembly in question may be readily disconnected.” Frank’s Casing Crew, No. CIV-01-104-F, slip. op. at 16 (W.D.Okla. July 22, 2002).
*1376 Following the district court’s claim constructiоn, Frank’s filed a motion for summary judgment of infringement. Weath-erford filed a cross motion for summary judgment of non-infringement. In granting summary judgment of no literal infringement, the district court found “that no reasonable jury could find an insubstantial difference between the two raising and lowering mechanisms” of claims 6, 7, and 8, and of Weatherford’s StabMaster. Frank’s Casing Crew, No. CIV-01-104-F, slip. op. at 26 (W.D.Okla. May 28, 2003). The court concluded: “The two mechanisms represent two distinct structural aрproaches to performing essentially the same function [and] [e]ach approach has its advantages and disadvantages.” Id. The district court also found no infringement under the doctrine of equivalents for the same reasons and no literal infringement under § 112, ¶ 6. Finally, the district court expressly noted that the raising and lowering mechanism of the StabMaster was not based on “after-developed technology.” Id. The district court also held that the prosecution history of the ’386 patent “amounted to a disclaimer” of the “below-mounted and directly-attached lifting means.” Id. On appeal, Frank’s challenges the district court’s interpretation of the claimed “means for selectively pivoting” clause and the term “detachably” as well as the summary judgment of non-infringement.
In a separate ruling, the district court denied Weatherford’s request for attorney fees and costs, declining to find the case “exceptional” under 35 U.S.C. § 285. Frank’s Casing Crew, No. CIV-01-104-F (WD.Okla. July 18, 2003). Weatherford cross appeals the district court’s finding that this case was not exceptional.
II.
This court reviews a district court’s grant of a motion for summary judgment without deference.
Kemco Sales Inc. v. Control Papers Co.,
III.
As noted, the claim element “means for selectively pivoting” is in means-plus-function format and governed by § 112, ¶ 6. A means-plus-function limitation requires a court first to identify the claimed function and then to determine the structure in the specification that corresponds to that function.
Omega Eng’g, Inc. v. Raytek Corp.,
The district court determined that the structure for this function necessarily includes a lift plate under the boom. The specification amply supports the trial court’s identification of corresponding structure. The only structure identified in the ’020 patent for performing the pivoting function is the lift plate under the boom. Id. at Figures 3-5, col. 11, 11. 5-18. The ’020 patent discloses a piston and cylinder subassembly, but any mention of that subassembly in connection with the lifting function includes a connection to the lift plate. Id. at Figures 3-5, col. 11,11. 5-18. In other words, the specification on occasion refers to the piston and cylinder subassembly without mentioning the lift plate, id. at Abstract; col. 10, 11. 44-50; col. 11, 11. 21-23; col. 17, 11. 15-22, but the only embodiment showing use of the piston and cylinder subassembly discloses a direct connection to the lift plate. The district court correctly identified the lift plate as necessary structure for the lifting function.
The prosecution history supports the district court’s reading of the claims. In distinguishing the Swoboda device, the applicant stated that the lifting cylinder “simply cannot be used” when directly connected to the boom. Amendment at 41 (emphasis in original). This statement underscores the essentiality of the lift plate to the claimed function.
A consistent reading of the claims also supports the trial court’s claim construction. In other words, “the same terms appearing in different portions of the claims should be given the same meaning unless it is clear from the specification and prosecution history that the terms have different meanings at different portions of the claims.”
Fin Control Sys. Pty, Ltd. v. OAM, Inc.,
In this case, this court observes that the patent includes claims with a yawing function. The term “means for selectively pivoting” should have the same meaning in these claims as in claims 6 through 8, unless the specification gives some reason to expect otherwise. Because the specification does not suggest any reason to depart from a сonsistent meaning, the pivoting limitation includes a lift plate located under the boom. Otherwise the device could not perform a yawing function.
This court recognizes that the principle of consistency within claims operates within the framework of related claims.
Epcon Gas Sys. Inc. v. Bauer Compressors, Inc.,
Turning now to the infringement inquiry, literal infringement requires that each and every limitation set forth in a claim appear in an accused product.
Becton Dickinson & Co. v. C.R. Bard, Inc.,
Because structural equivalents under § 112, ¶ 6 are included within literal infringement of means-plus-function claims, “the court must compare the accused structure
with the disclosed structure,
and must find equivalent
structure
as well as
identity
of claimed
function
for the structure.”
Pennwalt Corp. v. Durand-Wayland, Inc.,
There is also no possible equivalent under the doctrine of equivalents. The primary difference between structural equivalents under § 112, ¶ 6 and the doctrine of equivalents is a question of timing.
Al-Site Corp. v. VSI Int’l, Inc.,
Because affirming the district court’s claim construction of “means for selectively pivoting” and its finding of no infringement based оn that construction, this court need not address the district court’s claim construction of “detachably.”
IV.
Weatherford’s cross-appeal challenges the district court’s denial of attorney fees. This court reviews the district court’s denial of attorney fees under 35 U.S.C. § 285 for an abuse of discretion.
Va. Panel Corp. v. MAC Panel Co.,
This court detects no abuse of discretiоn in the district court’s ruling on attorney fees. In denying Weatherford’s motion for attorney fees and costs, the district court weighed a variety of factors, including the adequacy of Frank’s investigation before it sued Weatherford and the allegations of litigation misconduct based on its decision to persist in offering arguments dismissed by the district court’s July 22, 2002 Markman Order. Frank’s Casing Crew, No. CIV-01-104-F, slip. op. at 1-6 (W.D.Okla. July 18, 2003). On review of the record, this court agrees with the trial court that “[t]his is simрly not a case in which the conduct of the plaintiff, in filing and prosecuting the action, was offensive to the court (even mildly so).” Id. at 5.
V.
In sum, this court affirms the district court’s conclusion that the “means for selectively pivoting” must include a lift plate located under the boom and also affirms *1380 the district court’s summary judgment of non-infringement. In addition, this court affirms the district court’s denial of Weatherford’s request for attorney fees.
COSTS
Each party shall bear its own costs.
AFFIRMED
Notes
. The district court and the parties referred to these plates collectively as a "lift plate."
. The "means for selectively pivoting” limitations in claims 6, 7, and 8 are identical with the exception that the location where the boom "extends in a vertical direction” is identified as a "parked” location in claim 8. Because the parties agree that the addition of "parked” does not affect the claim construction of the limitations in a way that is pertinent to this case, this court treats these limitations identically.