Lead Opinion
Opinion for the court filed PER CURIAM. Circuit Judge RADER concurs.
The United States District Court for the Central District of California granted the motion of Titan Wheel International, Inc., Dyneer Corp., Transamerica Auto Parts Co., Inc., and Leon Rosser Auto Service, Inc. (collectively Tractech) for summary judgment of non-infringement of U.S. Patent No. 5,413,015 (the ’015 patent), assigned to Vehicular Technologies Corporation (PowerTrax). Bеcause the comparable assembly in the accused E-Z Locker product contains a single spring and a plug, the district court found that it cannot, as a matter of law, infringe the patented double-spring assembly. Because the record supports the district court’s judgment, this court affirms.
I.
This court has previously addressed the issue of the spring limitation in the ’015 patent in its earlier review of a preliminаry injunction. See Vehicular Techs. v. Titan Wheel Int’l, Inc.,
[A] long-standing need has existed for a differential mechanism which permits assembly, maintenance and repair in both manufacture and installation to be as simple as possible so that the likelihood of problems is greatly reduced.
’015 patent, col. 1, 11. 45-49. In its review of the preliminary injunction, this court further explained the assembly problems addressed by the invention:
The spring-disk-pin design of the pri- or art created special installation problems. Many locking differentials are designed as after-market add-ons whose parts can be installed into an existing differential by a do-it-yourself backyard mechanic. However, there is very little space inside a differential to install all the parts. With the spring-disk-pin design, each small part had to be carefully inserted in the tight space between the drive plates and then repositioned, often using a prying tool and a hacksaw blade to hold the parts in place and the spring in a compressed position. The disks were particularly troublesome because they slid around on the end of the spring and often fell off or were lost during installation.
The ’015 patent is directed toward an improved locking differential whose parts are easier to manufacture, install,and maintain than those of prior art locking differentials. The application for the ’015 patent, filed June 28, 1993, and listing John Zentmyer (Zentmyer) as the inventor, focused on three main improvements: (1) window openings in the outside rims of the drive plates, (2) newly dеsigned spring assemblies that use two concentric coil springs and a pin rather than a spring-disk-pin grouping, and (3) spring passageways with oblong cross-sections.
Vehicular Tech.,
1. A differential mechanism comprising:
output means;
driving means in spaced relationship to said output means; driven means operably responsive to said driving means for powering said output means;
said driven means hаving a pair of clutch driving members coaxially disposed with respect to each other and having opposing spaced-apart surfaces faces;
biasing means interposed between said driving surface faces comprising at least a pin in alignment with a spring assembly consisting of two concentric springs bearing against one end of said pin;
said springs and said pin in axial alignment disposed in an elongated passageway jointly provided in each of said pair of clutch drive members;
each of said clutch drive members has inspection and access openings communicating with said passageway so as to expose said springs and said pins respectively; and
said spring passageway is of oblong configuration in transverse cross-section.
’015 patent, col. 4,1. 65 to col. 5,1. 30
Tractech’s acсused device includes all of the claim limitations except the “spring assembly consisting of two concentric springs bearing against one end of said pin.” Tractech has substituted a single spring and a plug fitting into the spring for this limitation. One surface of Trac-tech’s plug bears against one end of the pin. Figure 5 from Tractech’s U.S. Patent No. 5,715,733 shows the concentric spring feature of the ’015 invention - represented as prior art in Tractech’s later patent - and Figure 7 from that patent illustrates Tractech’s accused device:
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In the prior art device of Figure 5, spring 128 fits within spring 124 and the two springs compress against pin 126. In Traetech’s accused device of Figure 7, plug 228 fits within spring 224. The smaller-diameter part of the plug, 228b, is held inside single spring 224 while the larger-diameter part of the plug. 228a, bearsagainst pin 226.
The district court initially granted Pow-erTrax’s motion for a preliminary injunction, finding that PowerTrax had shown a reasonable likelihood of success in proving Tractech’s spring-and-plug assembly
On appeal, this court vacated the preliminary injunction. In its analysis of the role played by each limitation in the context of the claim, see Warner-Jenkinson Co. v. Hilton Davis Chem. Co.,
SUMMARY OF THE INVENTION
Another object of the present invention is to provide a differential mechanism wherein сomponent parts of the assembly, such as clutch members, are joined together by a resilient means comprising a pair of oppositely-wound concentric springs bearing against a pin so that the strength of the spring and reliability of the resilient means are increased.
’015 patent, col. 2,11.14-20.
DESCRIPTION OF THE INVENTION
[Because of the dual spring feature], should one spring break or become weakened, the mechanism will cоntinue to function as the second spring will bear the load and prevent the broken spring from exiting the assembly.
Id., col. 4,11. 26-29.
Thus, this court read the specification to endow the dual-concentric spring assembly with “the ability to stay centered on the end of the pin and to continue functioning” even when one spring breaks. See Vehicular Tech.,
On remand, the district court, after hearing аdditional evidence, granted Trac-tech’s motion for summary judgment. The trial court reasoned that “the patent contains unmistakable assertions disavowing all devices without a double-spring assembly.” Vehicular Techs. Corp. v. Titan Wheel Int'l, Inc., No. SA CV 96-216 AHS
II.
This court reviews the district court’s summary judgment ruling de novo, reapplying the summary judgment standard. See Conroy v. Reebok Int'l, Ltd.,
In assessing issues of material fact to determine whether a “reasonable jury” could disagree on them, this court identifies facts pоsing a potential dispute and then examines those facts in the context of the legal criteria by which a fact finder would resolve the dispute. The only material facts potentially in dispute in this case involve the question of whether Trac-tech’s spring-plus-plug, which bears against the end of a pin, infringes under the doctrine of equivalents the claimed “spring assembly comprising two concen-trie springs bearing against one end of said pin.”
Infringement under the doctrine of equivalents requires an intensely factual inquiry. See Warner-Jenkinson,
Infringement - either literal or by equivalents - depends on the meaning and scope of the claimed invention. Markman v. Westview Instruments, Inc.,
The record does contain some evidence that inventors and artisans of ordinary skill discounted the importance of the reliability objective. For example, the designer of Tractech’s accused product did not list redundancy or reliability as a function of the two-spring design. Indeed, Trac-tech’s effort to design around thе invention does not document any reliability function for the concentric spring feature. The inventor of the ’015 product later disavowed the “increased reliability” objective, asserting that his objectives included only those relating to ease of assembly and expense of manufacture. This court must inquire whether this evidence creates a genuine issue of material fact or suffices to permit a reasonable jury to discount the importance of the reliability function and find infringement.
This court agrees with the district court that this record does not create a genuine issue of material fact, for several reasons. The specification of the ’015 patent, as noted above, mentions “reliability of the resilient means” as “[ajnother objective” - listed first after the “primary objeсt” of simplifying manufacture and installation. Further, as already noted, the specification discusses that the claimed invention with two springs will “continue to function” after one spring breaks. In other words, the extrinsic evidence invoked by Power-Trax to show a potential issue of fact relating to the importance of the reliability issue does not trump the clear disclosures and assertions in the patent itself. This court’s assessment of this same extrinsic evidence in the preliminary injunction review shows that this evidence is insufficient to‘Create a genuine issue of material fact:
[W]e reject PowerTrax’s argument that undisputed testimony from both parties’ witnesses established that the cap of the E-Z Locker is equivalent to the spring assembly claimed in the ’015 patent. First, we are not persuaded by the litigation-induced рronouncements of the inventor, Zentmyer, and other Pow-erTrax witnesses, because the written description clearly states the importance of the back-up function performed by the claimed dual spring assembly.... Second, much of the cited testimony by Tractech employees is not directed to the back-up function of the inner spring. This testimony, which PowerTrax submitted as admissions of equivalence, does not speak directly to the issue of equivalence of the claim limitations, but rather speaks to the overall structure and function of the E-Z Locker differentials .... Finally, to the extent that Tractech employees may have testified that they did not believe a back-up spring was necessary for satisfactory performance, that testimony is contradicted by the cleаr statements to the contrary in the ’015 patent.
Vehicular,
Turning to the question of whether no reasonable jury could find infringement by equivalents, this court notes that the range of equivalents cannot be divorced from the scope of the claims. See Warner-Jenkinson,
As this court noted in Vehicular, the drafter’s choice of the phrase “consisting of’ does not foreclose infringement under the doctrine of equivalents. This court clarified in Vehicular that “the claims specifically require that an infringing device consist of two springs (either literally or equivalently).” Vehicular,
COSTS
Each party shall bear its own costs.
AFFIRMED.
Concurrence Opinion
concurring.
This case presents the difficult problem of performing a doctrine of equivalents analysis on the limited facts available for a motion of summary judgment. However, because this case fits well within this court’s reasoning in Sage Products, Inc. v. Devon Industries,
In Sage,
[t]he case raise[ed] the question of why the law restricts application of the doctrine of equivalents without further fact finding in some cases, see, e.g., Conopco, Inc. v. May Dep’t Stores Co.,46 F.3d 1556 , 1562, 32 USPQ2d 1225, 1228 (Fed.Cir.1994); Dolly,16 F.3d at 400 , 29 USPQ2d at 1771, while in other cases the law imposes no such restriction, see, e.g., Hilton Davis Chem. Co. v. Warner-Jenkinson Co.,114 F.3d 1161 , 1163-64, 43 USPQ2d 1152, 1154-55 (Fed.Cir.1997) (in banc) (after remand from the Supreme Court; order permitting factual analysis of equivalence to stand). The claim at issue define[d] a relatively simple structural device. A skilled patent drafter would foresee the limiting potential of the “over said slot” limitation. No subtlety of language or complexity of the technology, nor any subsequent change in the state of the art, such as later-developed technology, obfuscated the significance of this limitation at the time of his incorporation into the claim. See, e.g., Pennwalt,833 F.2d at 938 , 4 USPQ2d at 1742 (“[T]he facts here do not involve later-developed computer technology which should be deemed within the scope of the claims to avoid the pirating of an invention.”). If Sage desired broad patent protection for any container that performed a function similar to his claimed container, it could have sought claims with fewer structural encumbrances. Had Sage done so, then the Patent and Trademark Office (PTO) could have fulfilled his statutory role in helping to ensure that exclusive rights issue only to those who have, in fact, contributed something new, useful, and unobvious. Instead, Sage left the PTO with manifestly limited claims that it now seeks to expand through the doctrine of equivalents. However, as between the patentee who had a clear opportunity to negotiate broader claimsbut did not do so, and the public at large, it is the patentee who must bear the cost of his failure to seek protection for this foreseeable alteration of his claimed structure.
Sage,
In this case as in Sage, a skilled patent drafter would readily foresee the limiting potential of the “consisting of two concentric springs” limitation. Again, the drafter would not confront the need for particularly subtle or ambiguous language to describe inventive features that are complex, or were never described before in scientific discourse. Moreover, this limitation does not call into question issues of after-arising technology which, by definition, cannot be foreseen at the time of claim drafting. Here, a skilled patent drafter could have reasonably foreseen potential substitutes for two concentric springs, such as the accused spring and plug structure, but nonetheless chose limited claim terms. In such a сase as this, this court does not employ the doctrine of equivalents to alter the limitations the drafter chose to prosecute in the Patent and Trademark Office.
In this case, the principles enunciated in Sage are particularly applicable because the patent owner learned of the alleged infringement within the two-year period allowed for reissuing a patent under 35 U.S.C. § 251 (1994). Section 251 permits a patentee, whо “through error without any deceptive intent ... claimfs] more or less that he had a right to claim,” to enlarge the patent claims within two years of the grant of the original patent. Id.; Hewlett-Packard Co. v. Bausch & Bomb, Inc.,