On Tuesday of last week, the Federal Circuit gave Import Global a second chance in district court, reminding practitioners of the importance of careful claim language and a detailed written description. In Socket Solutions, LLC v. Import Global, LLC, the appellate court vacated and remanded a Florida district court’s grant of a preliminary injunction, concluding that the district court had misconstrued the claims and that, as a result, the likelihood of success required for injunctive relief had not been met.
Background
Socket Solutions, LLC, owns U.S. Patent No. 9,509,080 (the ʼ080 patent) — an indoor electrical wall outlet cover that permits functional use of an electrical wall outlet while fully concealing the plug contact openings of the outlet — and sells the patented product under the name Sleek Socket. At issue in this suit is claim 19 of the ʼ080 patent, which requires an apparatus for hiding a wall outlet while affording use of the outlet comprising (emphasis added):
- a cover comprising:
- i. a frontplate; and
- ii. a backplate comprising at least one set of electrical prongs including a hot prong, a neutral prong, and optionally a ground prong, positioned to correspond to a first receptacle of the wall outlet; and
- an electrical cord extending from the backplate, or the cover, said cord comprising at the cord’s proximal end: at least one hot pin, at least one neutral pin and optionally a ground wire positioned on or fastened or attached to the backplate of the cover in such manner as to minimize distance between the front plate and the backplate.
Alleging that Import Global infringed claim 19 of the ʼ080 patent, Socket Solutions sued and moved for a preliminary injunction. The motion was granted after determining Socket Solutions demonstrated a likelihood of success on the merits of its infringement claim. Import Global appealed, and the appellate court reviewed the grant of injunctive relief.
The Federal Circuit’s Analysis
In its review, the Federal Circuit focused on the district court’s construction of two terms as adopted from Socket Solutions’ recommendation: “backplate” and “pin.” The district court had construed “backplate” as the component of the cover, opposite the frontplate, that includes at least one set of electrical prongs. The Federal Circuit held that this construction erroneously imposed a spatial-reference requirement relative to the “frontplate” that the specification does not require. For the same reason, it declined to adopt Import Global’s proposed construction that the “backplate” is the portion of the apparatus closest to the wall outlet once the apparatus is plugged in. Relying on the written description, the Federal Circuit instead construed “backplate” as the component that, together with the frontplate, forms the cover, such that the cover’s maximum thickness is measured at its central portion between the frontplate and that component.
In agreement with Import Global, the Federal Circuit determined the district court incorrectly construed “pin” as a means-plus-function term. Under 35 U.S.C. § 112(f), a patentee may draft claims as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof. When a claim term lacks the word “means,” there is a rebuttable presumption that § 112(f) does not apply. While that presumption can be overcome, the Federal Circuit held it remains intact where, as here, the written description further defines the claim term (“pin”) in structural terms.
Socket Solutions did not dispute that “pin” is a structure but argued that courts have construed structural terms in purely functional language without triggering § 112(f) when the structural element is best defined by its function. The Federal Circuit disagreed, reasoning that a purely functional definition would be overly broad. The appellate court reiterated that it departs from a claim term’s plain and ordinary meaning only through lexicography or disavowal, so, finding no prosecution history here suggesting otherwise, the appellate court gave “pin” its plain and ordinary meaning as understood by a skilled artisan.
Considering this determination, the Federal Circuit vacated the district court’s grant of a preliminary injunction and remanded for the court to reevaluate the likelihood of success of Socket Solutions’ infringement claim under the ʼ080 patent. The appellate court did not reach the merits of Import Global’s irreparable harm arguments.
Key Takeaways
- Courts will not rewrite the claims. A court must look at the written description and patent prosecution to interpret claim language and will not add or omit limitations to reach a favored outcome, so claims should be written as they are intended to be interpreted.
- Functional language doesn’t automatically trigger § 112(f). A broad claim term reciting a function is not converted into a means-plus-function limitation merely because the element could also be described functionally, so if a mean-plus-function is intended, the limitation should include “means.”
- Courts will not read between the lines. Where spatial referencing is important to a product, it should be stated explicitly in the written description, as an appellate court is unlikely to infer product features on its own.










