US 4936494

I'll verify the details against live sources before summarizing.

One more check for any recent (2026) litigation activity.

Summary — US Patent 4,936,494

Sources used: the full patent text at https://patents.google.com/patent/[US4936494](/patent/US4936494)/en (fetched 2026‑09‑30), the PDF at https://patentimages.storage.googleapis.com/7c/21/16/a1c6f3efff18d0/US4936494.pdf, and the litigation record in Weatherchem Corp. v. J.L. Clark, Inc., 937 F. Supp. 1262 (N.D. Ohio 1996) and 163 F.3d 1326 (Fed. Cir. 1998). All identifiers below are transcribed literally from those sources.

Bibliographic data

Abstract (as printed)

"A shake-and-spoon cap for condiment containers and the like is formed of a one-piece injection-molded body. The cap provides a cylindrical skirt having inwardly projecting thread forms for mating with the male threads of a condiment container or the like. Two flaps are provided for selectively opening and closing a spoon opening and a plurality of shaker openings. The cap is structured so that the exposed end of the cap is a circular, planar surface when the flaps are closed. A sealing land inwardly spaced and concentric with the skirt is positioned to seal with the mouth of a container. The interior and exterior surfaces of the end wall are contoured so that substantially the entire cap has a uniform wall thickness. Peripherally spaced, radially extending ribs stiffen the cap between the land and the skirt to resist deflection and to ensure that the flap latching structure functions reliably."

Plain-language overview of the disclosure

The '494 patent is a design refinement of Weatherchem's own earlier "shake-and-spoon" cap (U.S. 4,693,399, incorporated by reference). The problem addressed is injection-molding quality: thermoplastic shrinks on cooling, and a non‑uniform wall causes ovality, sinkholes, and long "time‑in‑mold." The '494 cap therefore keeps a roughly uniform 0.05 inch wall except at the sealing land (36) and the helical thread projections (32), contoured so the closed flaps give a flat circular top surface. The seal is made by a circular planar sealing land spaced inward from the skirt, rather than at the skirt wall. Because that thin end‑wall region between land and skirt can flex when the cap is torqued onto a container — which would let the flap latches pop open — the patent adds a plurality of closely spaced radial reinforcing ribs (71) between the land and the skirt, characterized as "anchoring" the land/end wall by transferring the skirt's (and threaded container mouth's) inherent stiffness to it. Figures 1–2 also show a gate projection (58) recessed so it does not protrude after break‑off, and the illustrated embodiments are sized for 53 mm and 63 mm container mouths.

Independent claims — plain language

Claim 1 (cap, single-opening variant) — A dispensing cap that is a one‑piece injection‑molded plastic body with a circular end wall and a cylindrical skirt; the end wall has at least one opening through which contents can be removed with the cap left on; a hinged flap closes that opening and cooperates with the end wall to form latch means. A relatively flat sealing land projects from the interior of the end wall, spaced radially inward from the skirt and joined to it by an end‑wall portion, and seals against the container's circular mouth; the skirt has internal threads. Screwing the cap on presses the container mouth against the sealing land, producing forces along the periphery of the end wall normal to it, which would tend to deflect that end‑wall portion and make the latch malfunction. The claimed fix is a plurality of reinforcing ribs that extend below the end‑wall portion radially between the sealing land and the skirt, disposed on the inner periphery of the skirt at a multitude of relatively closely spaced locations, so that the ribs "anchor" the end‑wall portion and land by imparting the skirt's (and indirectly the threaded container mouth's) inherent stiffness to them, resisting deflection and preventing latch malfunction.

Claim 9 (cap, two‑mode variant) — Same one‑piece thermoplastic body/end wall/threaded skirt structure, but claimed as the shake‑and‑spoon cap itself: a spooning opening on one side large enough to pass a spoon, and a shake side with a plurality of small apertures on the other; a first hinged flap for the spooning opening and a second hinged flap for the small apertures; cooperating releasable latch means; the end wall contoured so end wall plus flaps give a substantially planar, circular exterior face when closed. It adds the same inward‑spaced relatively flat sealing land and limited‑thickness wall portion joining land to skirt, the same normal‑to‑end‑wall threading forces that would deflect that wall portion and cause latch malfunction, and the same peripherally spaced radial reinforcing ribs between the land and skirt at a multitude of closely spaced locations providing the anchoring/stiffening action.

Claim 13 (combination claim — container plus cap) — Recites, in combination, a container to be filled with granular material having a threaded mouth, plus a dispensing cap consisting of a one‑piece injection‑molded plastic body with circular end wall and threaded skirt engaging the container threads; at least one opening and a hinged flap with latch means as above; a sealing surface spaced inward from the skirt sealing against the container mouth; tightening the cap subjects the end wall periphery to a normal force that would deflect it and make the latch malfunction. The distinguishing recitation here is that the sealing surface is a circumferentially continuous annulus spaced radially inward of the ribs and lying in a flat plane, with the ribs disposed on the inner periphery of the skirt at a multitude of closely spaced locations and providing the anchoring action.

Claim 14 (cap claim, same subject matter as 13 without the container) — Identical structural recitation except that the container is not part of the claim: cap with a sealing surface along the interior of the end wall spaced inward from the skirt, and reinforcing ribs below the end wall radially between sealing surface and skirt at closely spaced locations on the inner skirt periphery, the sealing surface again being a circumferentially continuous annulus in a flat plane inward of the ribs.

The remaining claims are dependent, all others being dependent on Claim 1 (Claims 2–8) or Claim 9 (Claims 10–12): uniform wall thickness (2, 11); planar exposed surface when the flap is closed (3); recessed flap‑receiving portion with interiorly recessed projections (4); spoon opening plus small shake apertures and two flaps (5); land spaced from the skirt by at least about twice the wall thickness (6, 12); planar sealing surface projecting beyond the rest of the end wall (7); contoured end wall giving a smooth planar exterior and uniform wall (8, 10).

Litigation history (verified)

• Weatherchem Corp. v. J.L. Clark, Inc., No. 1:91‑CV‑0035 (N.D. Ohio), 937 F. Supp. 1262 (Aug. 30, 1996) — After a bench trial, the court held both patents invalid: the '399 patent under the on‑sale bar, and the '494 patent as obvious over the '399 patent combined with the "Rosam II" cap (eight ribs found to be a "plurality" at closely spaced locations). In the alternative the court held the '494 claims not infringed. https://case-law.vlex.com/vid/weatherchem-corp-v-jl-892888261 and https://app.midpage.ai/document/weatherchem-corp-v-j-l-[2250493](/patent/2250493)
• Weatherchem Corp. v. J.L. Clark, Inc., 163 F.3d 1326 (Fed. Cir. Dec. 7, 1998), Nos. 98‑1064, 98‑1078 — The Federal Circuit affirmed the invalidity determination (no clear error in the obviousness findings under the Graham factors) and vacated the non‑infringement portions of the judgment as moot. https://law.justia.com/cases/federal/appellate-courts/F3/163/1326/[494298](/patent/494298)/
• Google Patents carries a "Family has litigation" flag for family ID 22840245, pointing to Darts‑ip. https://patents.darts-ip.com/?family=22840245
• Related instruments worth noting: US RE37,634 E, "Two‑flap closure," is a reissue of the '399 patent (not of the '494), naming Hickman, Weidman and Kriska. U.S. 5,048,730 (Weatherchem, Forsyth et al.), U.S. D331878 and U.S. 5,330,082 list the '494 patent as a reference/related art.

Explicit uncertainties

1. No 2026 litigation found. I found no Federal Circuit or district court docket activity in 2026 involving 4,936,494. The only litigation I can verify is the 1991–1998 matter above. Given the anticipated expiration of 2008‑07‑26 and the Federal Circuit's 1998 affirmance of invalidity, I would not expect live enforcement activity — but I cannot affirmatively prove the absence of a 2026 docket entry from the sources I consulted, and I did not have direct access to PACER/CAFC docket systems.
2. Claim‑text wording differences. The Claim 9 text as printed on Google Patents differs slightly from the version quoted by the courts (e.g., the court's quotation reads "said end wall also providing a relatively flat sealing land inwardly spaced from said skirt having a region adapted to engage the seal with the mouth of said associated container producing forces…"). These appear to be OCR/transcription variants. The authoritative wording is the granted patent PDF; I have flagged rather than silently "corrected" the difference.
3. Assignee name variants appear in the record ("Weatherchem Corp" vs. "Weatherchem Corporation, a corp. of OH"); both refer to the same Twinsburg, Ohio entity as listed.
4. The patent document itself is marked "Expired – Lifetime" with anticipated expiration 2008‑07‑26; the Darts‑ip litigation flag is a database annotation and not a legal conclusion.

I'll research litigation involving US Patent 4,936,494. Let me run several targeted searches.

Found a strong lead. Let me dig deeper into the specific case and look for any others.

Let me verify the case details and check for any additional litigation (e.g., other defendants or later suits).

Litigation Involving U.S. Patent No. 4,936,494

Bottom line

One litigation is confirmed in which U.S. Patent No. 4,936,494 ("the '494 patent," Two-flap container closure, Craig C. Weidman, assigned to Weatherchem Corp., filed July 26, 1988, issued June 26, 1990) was asserted:

Weatherchem Corporation v. J.L. Clark, Inc.

I could not confirm any other U.S. district court action, ITC investigation, or PTAB proceeding asserting or challenging the '494 patent specifically.

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The case

District court outcome

• '494 patent — held invalid for obviousness over the '399 patent in combination with a spice cap used by the Rosam Spice company (the "Rosam II" cap), which the court found met all '494 claim limitations except that it had two sprinkle openings rather than a sprinkle opening and a spoon opening. 937 F. Supp. at 1286–89.
• '494 patent — alternatively held not infringed (an alternative holding reached "for completeness and in the interest of aiding appellate review"). 937 F. Supp. at 1290–92.
• '399 patent — held invalid under the on-sale bar (commercial activity "at the very latest, in late September 1985").
• '399 patent — held infringed by Clark, and no inequitable conduct found as to either patent.
• Weatherchem's Fed. R. Civ. P. 52(b) motions (on-sale-bar findings and '494 claim construction) were denied.

Federal Circuit outcome

The court affirmed in part, modified in part, and vacated in part. The most significant appellate development was that the Supreme Court decided Pfaff v. Wells Electronics, Inc., 525 U.S. 55 (1998), three weeks before the Federal Circuit's decision; the Federal Circuit accordingly vacated the '399 on-sale-bar determination and remanded for reconsideration under the Pfaff two-condition test (commercial offer for sale + ready for patenting). The Federal Circuit's analysis of the '494 patent's structure — the annular sealing surface (36) spaced inside the skirt (11) plus the peripherally spaced radial reinforcing ribs (71) that stiffen the end-wall portion and prevent flap-latch malfunction — is set out at 163 F.3d at 1328–30.

⚠️ Confidence caveat on the precise appellate disposition of the '494 invalidity ruling. I am confident about the case identity, court, docket number, district court result, and the Federal Circuit's Pfaff-driven vacatur/remand of the '399 on-sale-bar ruling. I am less certain whether the Federal Circuit expressly affirmed the '494 obviousness holding or disposed of it in some other way (e.g., mooting the alternative non-infringement holding). I could not re-verify this because my searches were cut off. This point should be confirmed against the full text of 163 F.3d 1326 before being relied upon.

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Why the '494 patent was at issue

Both patents were Weatherchem's "shake-and-spoon" two-flap condiment caps. Per the Federal Circuit, the '494 cap "differs from the '399 cap primarily in the way the cap forms a seal with the container": the '494 patent uses an annular sealing surface inside the skirt plus radial stiffening ribs to prevent end-wall deflection from causing latch malfunction — exactly the ribs (71) recited in claims 1, 9, 13, and 14 of the patent. The patent's commercial embodiments were sized for 53 mm and 63 mm container mouths, and the patent expired (anticipated) on July 26, 2008.

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Literal-identifier caution (per your strict rule)

Searching the bare string "4936494" returns several different identifiers that are not U.S. Patent 4,936,494 and must not be conflated with it:

• JP 4936494 B1 (Japanese Patent No. 4936494, "宝石の損傷防止方法," registered 2012-03-02) — an unrelated Japanese patent.
• FEI/EIN 99-4936494 — a Florida LLC annual report for Watkins Car Care, LLC; not a patent at all.
• Various design patents (e.g., USD331878, USD537341, USD565408) merely cite US 4,936,494 as a reference — citation is not litigation.

I treated only the literal U.S. Patent No. 4,936,494 as in scope.

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Family-level litigation flag

The Google Patents family record for US 4,936,494 (family ID 22840245) carries a "Family has litigation" flag with a Darts-IP link:
https://patents.darts-ip.com/?family=22840245

This flag is consistent with the Weatherchem v. J.L. Clark action above. Because that family flag aggregates the U.S. patent with its foreign counterparts (AU 33899/89, CA 1324590, GB 2221211, DE 3917057, FR 2634738), it may also reflect non-U.S. proceedings or family-level litigation that I was unable to enumerate. I cannot confirm any specific foreign suit.

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What I could not confirm

• Whether Weatherchem asserted the '494 patent against any defendant other than J.L. Clark (e.g., in the parallel '399/RE37,634 dispute line involving Durkee Foods or other cap makers). No such action surfaced.
• Any ITC Section 337 investigation involving the '494 patent — none found.
• Any PTAB (IPR/PGR/CBM) or reexamination proceeding on the '494 patent — none found (the patent expired in 2008, before the AIA trial regime matured).
• The exact filing date of No. 1:91-CV-35 (1991 based on docket numbering, exact day not verified).
• Any later related cases involving the '494 patent after the 1998 Federal Circuit decision.

Sources

• Google Patents record: https://patents.google.com/patent/US4936494/en
• Weatherchem Corp. v. J.L. Clark, Inc., 937 F. Supp. 1262 (N.D. Ohio 1996) — https://case-law.vlex.com/vid/weatherchem-corp-v-jl-892888261 and https://app.midpage.ai/document/weatherchem-corp-v-j-l-[2250493](/patent/2250493)
• Weatherchem Corp. v. J.L. Clark, Inc., 163 F.3d 1326 (Fed. Cir. 1998) — https://law.justia.com/cases/federal/appellate-courts/F3/163/1326/[494298](/patent/494298)/ ; https://www.courtlistener.com/opinion/[760245](/patent/760245)/weatherchem-corporation-v-jl-clark-inc-defendantcross-appellant/ ; http://www.worldlii.org/us/cases/federal/USCAFED/1998/202.html
• Case-list portals consulted: Unified Patents litigation portal (https://portal.unifiedpatents.com/litigation/caselist), CourtListener, Justia, Casetext, OpenJurist. No '494-specific entry was found in the Unified Patents litigation portal, which is expected given the 1991–1998 vintage of the case (predating that database's coverage).

If you want, I can attempt to retrieve the full text of the 1998 Federal Circuit opinion and the 1996 district court opinion to nail down the exact appellate disposition and the precise filing date — those two items are the remaining open gaps.

I'll verify the absence of PTAB activity against live sources before writing this up.

PTAB / AIA Trial Proceedings — U.S. Patent 4,936,494

Verification basis: the structured "PTAB proceedings on file" block supplied with this prompt (USPTO Open Data Portal ingest: no AIA trial proceedings), cross-checked against live web search of PTAB petition/decision repositories, PTAB E2E public materials, Docket Alarm PTAB dockets, and CAFC opinion databases. I did not have direct API access to PTAB E2E during this pass; the searches were consistent with the ODP result, and the only "494" PTAB hits that surfaced were for a different patent (flagged below).

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Proceedings overview

Total AIA trial proceedings on U.S. Patent 4,936,494: 0 — 0 active, 0 with claims invalidated by the Board, 0 with claims sustained, 0 terminated by settlement, 0 institution denials.

The bottom-line defensive posture is therefore not a PTAB story at all: this patent is not "hardened" and does not need an IPR to defeat it — it expired on 2008‑07‑26 ("Expired – Lifetime"; anticipated expiration per Google Patents), and its three asserted independent claims (9, 13, and 14) were held invalid for obviousness by a final district court judgment that the Federal Circuit expressly affirmed on 1998‑12‑07. A demand letter citing claims 9, 13, or 14 of the '494 patent is citing claims that have been adjudicated invalid and that no longer exist as enforceable rights. The only residual theory would rest on never-adjudicated claim 1 and its dependents (2–8), and even that is foreclosed in practice by expiration and the six-year damages lookback of 35 U.S.C. § 286.

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No proceedings on file — the (empty) proceeding list

There is no {PROCEEDING_NUMBER} — {Petitioner} v. Weatherchem Corporation to report. Stating the fields anyway, for the record:

• Type: none (no IPR, no PGR, no CBM)
• Filed: N/A
• Status: N/A — ODP returns no AIA trial proceedings
• Judge panel: none empaneled
• Petition grounds: none
• Institution decision: none
• Final Written Decision: none
• Settlement / termination: none
• Appeal (PTAB appeal under 35 U.S.C. § 141): none. The only Federal Circuit appeal touching this patent was from the district court case: Nos. 98‑1064, 98‑1078, Weatherchem Corp. v. J.L. Clark, Inc., 163 F.3d 1326 (Fed. Cir. 1998-12-07).
• Defensive value: High, but not because of the Board — because of Article III. See the strategic summary.

Why the AIA trial toolbox was structurally unavailable: the '494 patent has an effective filing date of 1988‑07‑26, so it is far outside the window for Post-Grant Review (available only for patents with effective filing dates on or after 2013‑03‑16). Covered Business Method review was categorically inapt — the '494 patent claims a condiment-container cap, not a "financial product or service" — and the CBM transitional program sunset for new petitions on 2020‑09‑16 (AIA § 18(a)(3)(A)). IPR did not become available until 2012‑09‑16, more than four years after the patent's 2008‑07‑26 expiration. In practical terms, no AIA petition against this patent could have been worth filing.

Near-misses and literal-identifier traps (do not conflate)

• U.S. Patent 7,265,494 B2 — "Intelligent user interface with touch sensor technology," Global Touch Solutions, LLC. This patent is challenged in IPR2015‑01025 ([Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.) / Microsoft Mobile, Inc., filed 2015‑04‑10), IPR2015‑01616 (Toshiba Corp., Toshiba America Information Systems, Inc., Apple Inc., filed 2015‑07‑23), and IPR2015‑01928 (Microsoft; final written decision 2016‑12‑28 addressing claims 1, 3, and 20). The petitions and decisions repeatedly abbreviate it as "the '494 patent." It is not U.S. 4,936,494. One petition describes "the '494 patent" as a "microchip controlled switch … electronic unit" for flashlights — a tell-tale sign you have the wrong document. See e.g. https://www.docketalarm.com/cases/PTAB/IPR2015-01928/Inter_Partes_Review_of_U.S._Pat._7265494/docs/12-28-2016-Board/Final_Decision-28-Final_Written_Decision.pdf
• JP 4936494 B1 — an unrelated Japanese patent; FEI/EIN 99‑4936494 — a Florida LLC annual report. Neither is a patent proceeding.
• US RE37,634 E — "Two-flap closure," a reissue of the '399 patent, not of the '494 patent. Its claims and file history relate to the '399 disclosure; do not treat its prosecution as '494 activity.
• No ex parte reexamination or reissue application directed to the '494 patent was found. Confidence on this point is medium-high, not certain: my last verification query on reexamination/reissue hit a tool step limit, so I verified the absence via the Google Patents legal-events record ("Expired – Lifetime"; FPAY entries only; no REMI/reexam events beyond maintenance-fee reminders) rather than by an exhaustive ODP "post-grant" query.

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Strategic summary

Claim-level status (statutory cancellation vs. judicial invalidation vs. untested). No claim of the '494 patent was ever canceled — the Board never had jurisdiction over it — but three of the four independent claims were adjudicated invalid. The asserted claims were 9, 13, and 14 (163 F.3d at 1327). The district court held "the asserted claims of the '494 patent invalid for obviousness over the '399 patent in combination with a cap used by the Rosam Spice company" (937 F. Supp. 1262, 1286–89 (N.D. Ohio 1996)), and the Federal Circuit affirmed: "In short, this court does not find clear error in the district court's findings under the Graham factors. Nor can this court say that, based on those findings, the district court erred in determining that the claims would have been obvious." Because it affirmed invalidity, the court vacated the alternative non-infringement judgment as moot. Only independent claim 1 and its dependent claims 2–8 — and, derivatively, dependent claims 10–12 — were never adjudicated. Those claims are untested, but expired (2008‑07‑26).

Correction to the earlier litigation section. That section flagged an unresolved uncertainty about "whether the Federal Circuit expressly affirmed the '494 obviousness holding or disposed of it in some other way." That gap is now closed: the Federal Circuit expressly affirmed the obviousness invalidity determination (¶¶ 42–44) and vacated only the non-infringement portion (¶ 45). The earlier summary's statement — "affirmed the invalidity determination … and vacated the non-infringement portions of the judgment as moot" — is the correct one.

Estoppel landscape. Because there are zero AIA proceedings, there is no § 315(e)(2) estoppel attaching to any party, and no petitioner is barred from any ground. That cuts both ways, and in the end it does not matter: estoppel is a constraint on how you may challenge a patent, not a source of invalidity. The '494 patent's problem is not procedural — it is that its asserted claims are dead by judgment (claim preclusion / collateral estoppel as to Weatherchem and its privies for those claims: 9, 13, 14) and the whole patent is long expired. Nothing in the AIA toolbox adds anything a defendant does not already have from the 1996/1998 judgments and the 2008 expiration date.

Pattern signals. None of the usual PTAB pattern markers are present. No serial petitioner, no defensive aggregator (no Unified Patents or RPX petition appears anywhere in the '494 record), no patent-owner appeal of any Board decision, no reissue or reexam of the '494. Weatherchem's post-issuance enforcement pattern was a single 1991–1998 campaign against J.L. Clark (No. 1:91‑CV‑35, N.D. Ohio) over the '399 and '494 patents together — a commercial-competitor fight, not a monetization program. Weatherchem's later IPR-era activity in the PTAB (if any) involved its other patents, not this one. The absence of PTAB activity is itself the signal here: well-asserted, live patents eventually attract IPRs; a patent that expired in 2008 and whose key claims were invalidated in 1998 never had the profile to attract one.

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Recommended next steps

1. If you have received a demand citing claims 9, 13, or 14: the FWD to cite is not a Board decision — it is the affirmed appellate judgment. Quote it: "Because this court affirms the determination of invalidity, this court vacates those portions of the judgment granting a declaration of noninfringement of the '494 patent…" — 163 F.3d 1326, ¶ 45 (Fed. Cir. 1998-12-07), https://law.justia.com/cases/federal/appellate-courts/F3/163/1326/[494298](/patent/494298)/ and https://www.courtlistener.com/opinion/[760245](/patent/760245)/weatherchem-corporation-v-jl-clark-inc-defendantcross-appellant/. Pair it with the district court's holding at 937 F. Supp. 1262, 1286–89 (N.D. Ohio 1996-08-30) (obviousness over the '399 patent + the Rosam II cap) and the Google Patents status line at https://patents.google.com/patent/[US4936494](/patent/US4936494)/en ("Expired – Lifetime"; anticipated expiration 2008‑07‑26).
2. If the demand cites claim 1 (or claims 2–8): those claims were never adjudicated, so you cannot simply point to the judgment. Your defenses are (a) expiration — there is no injunctive relief and the § 286 six-year recoverable-damages window is long exhausted; (b) the same obviousness theory (the '399 patent + the Rosam II cap) applies with equal force to claim 1 if you ever needed it in a court; and (c) laches/§ 282 invalidity under §§ 102/103. Note the Board cannot help you: a petition filed today would be against an expired patent, with no realistic prospect of institutional interest.
3. Do not file an IPR. There is no reason to. The patent cannot be asserted for injunctive relief, and its asserted independent claims have already been invalidated by an affirmed judgment. Filing would forfeit fees and confer no benefit.
4. If you must confirm the Board's docket yourself (e.g., for a formal opinion or an FTO memo), search PTAB E2E's "Patent Number" field for 4936494 at https://ptacts.uspto.gov/ (Patent Trial and Appeal Board End-to-End). Expect a null result. Cross-check the patent's ODP "Post Grant" documents tab and the Google Patents legal-events table (which shows only assignment, grant, and FPAY/maintenance-fee events through 2002) at https://patents.google.com/patent/US4936494/en.
5. Watch the literal-identifier trap. Any litigation or PTAB report that surfaces for "494" in this technology space is almost certainly U.S. 7,265,494 (Global Touch Solutions, IPR2015‑01025 / ‑01616 / ‑01928) or the unrelated JP 4936494 B1. Neither belongs in an analysis of U.S. 4,936,494.

I'll research the assignment record and ownership chain. Let me run several targeted searches.

Let me search for Weatherchem's corporate history and any ownership changes.

Let me verify whether any post-issuance assignments were recorded, and check for Mold-Rite/IP transfer records.

Inventors

Pattern notes. This is a classic single-inventor, employer-assigned filing with no inventor-side retention: Weidman executed the assignment to the corporate assignee essentially contemporaneously with filing, and no subsequent inventor-originated conveyance (no later assignment, no license, no release) appears in the record. The prior-art section of the specification refers to U.S. 4,693,399 as "assigned to the assignee of this invention," confirming a single corporate owner across the two-patent Flapper family. I could not determine from the sources consulted whether Weidman remained at Weatherchem 12 months after filing — no departure, no fire-sale signal, and no evidence of the "all inventors leave" pattern.

Original assignee

Weatherchem Corporation, an Ohio corporation, 2222 Highland Road, Twinsburg, OH 44087 (assignee named on the face of the patent and in the recorded assignment; assignment text styles it "WEATHERCHEM CORPORATION, A CORP. OF OH").

• Shipped a product embodying the claims? Yes — strongly indicated. Weatherchem manufactured the "shake-and-spoon" Flapper® dispensing closure, and the patent's own description ties the '494 structure to that product line (integral living-hinged spoon flap + shaker flap, uniform‑wall molding). The '399 patent, expressly incorporated by reference here, recited the same spooning opening and shaker apertures, and Weatherchem's public product literature (Flapper, LiquiFlapper, NutraFlapper, NutraGen II, FlapMate) confirms it was an operating closures manufacturer, not a licensing vehicle. The claims themselves were also commercially practiced by the defendant in the '494 litigation — the district court found the asserted claims were met by a competitor's cap (see Litigation section in the prior summary).
• Primary line of business: design and injection molding of plastic dispensing closures and end closures for food/spice, chemical, personal-care, pet-care and healthcare packaging. Founded 1971 when Albert J. Weatherhead III acquired Ankeny Co. and renamed it Weatherchem Corporation.
• Current status: Acquired — no longer an independent entity. In November 2012 (deal reported 2012‑11‑19 / announced 2012‑11‑30) Weatherchem Corporation was acquired by Mold-Rite Plastics, LLC, a portfolio company of private-equity firm Irving Place Capital (Plattsburgh, NY), which retained the Weatherchem name and brand. Mold-Rite later rebranded/consolidated as MRP Solutions. Weatherchem had ~$55M in 2011 sales. This was an M&A transaction, not a bankruptcy.

Assignment timeline

The USPTO Assignment Center exposes exactly one record for this patent; everything else is corporate-level M&A that was never recorded against US 4,936,494 (the patent had already reached anticipated expiration in 2008, four years before the Mold-Rite deal).

• 1988‑08‑04 (executed) / recorded 1988‑08‑11 — Reel 004929 / 0536
  • Conveyance: Assignment
  • Assignor: Weidman, Craig C. (sole inventor)
  • Assignee: Weatherchem Corporation, a corp. of OH
  • Correspondent: Not exposed in the sources I could retrieve. The Google Patents legal-events record for this patent surfaces only the owner name, assignor name, conveyance type, effective date and reel/frame (004929/0536); the recording correspondent (attorney/firm) is not carried in that feed, and I was unable to render the Assignment Center's results grid for patent 4,936,494 to read the correspondent field. I did not fabricate one.
  • Context: Original inventor-to-employer assignment executed nine days after filing — the standard, unremarkable pre-issuance conveyance by which a sole inventor assigns to his employer; no consideration terms or reversion appear.

No post-issuance assignment, security agreement, merger, change-of-name, or license is recorded against US 4,936,494. Specifically:

• The 2012 Mold-Rite Plastics acquisition of Weatherchem did not generate a recorded assignment on this patent. (Mold-Rite/Weatherchem/Stull security instruments with Wells Fargo, Deutsche Bank, Madison Capital and Acquum/Acquiom — reels 057697/0779, 057726/0681, 057723/0927, 057748/0174, 067679/*, 068568/0247, 068730/0001 — appear on Weatherchem's later, still-live patents such as US 8,205,761, not on the '494 patent, consistent with '494 having already expired.)
• The US RE37,634 E reissue belongs to the '399 patent (Hickman/Weidman/Kriska), not to '494, and creates no assignment entry here.

Verification limitation (stated plainly): assignmentcenter.uspto.gov is a JavaScript-rendered search application that I could not query directly, and the mirrored assignment.uspto.gov index returned no independent record for patent 4,936,494 in the results I obtained. My conclusion that reel 004929/0536 is the sole recorded conveyance rests on the Google Patents legal-events tab for this patent (https://patents.google.com/patent/US4936494/en), which is generated from the same USPTO assignment data. Confirm against the Assignment Center before relying on it in a diligence memo.

Timeline diagram

timeline
    title Ownership of US 4936494
    1971 : Weatherchem founded by Weatherhead
    1988 : Patent application filed July 26
         : Inventor assigns to Weatherchem reel 004929 0536
    1990 : Patent issued June 26
    1991 : Weatherchem sues J L Clark
    1996 : District court holds claims invalid
    1998 : Federal Circuit decision
    2008 : Patent reaches anticipated expiration
    2012 : Weatherchem acquired by Mold-Rite Plastics

NPE / troll-pattern signals

Verdict

Operating-company assertion.

The only recorded conveyance is the original inventor-to-employer assignment (reel 004929/0536, executed 1988‑08‑04, recorded 1988‑08‑11), and the chain never moves — Weatherchem Corporation holds the patent through issuance and through the sole litigation. That litigation, Weatherchem Corp. v. J.L. Clark, Inc., No. 1:91‑CV‑35 (N.D. Ohio 1996), aff'd in relevant part 163 F.3d 1326 (Fed. Cir. 1998), was brought by a product-shipping closures manufacturer against a competing closures manufacturer (J.L. Clark) — the textbook operating-company-versus-competitor posture, and the polar opposite of an NPE campaign. Every one of the eight NPE signals is either not present or (correspondent recurrence) untestable because there is only one link; the 2012 Mold-Rite/Weatherchem deal is unrelated M&A that occurred four years after this patent's 2008 anticipated expiration and was never recorded against it.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 4936494; also mirrored at https://assignment.uspto.gov/patent/index.html) and the patent record at https://patents.google.com/patent/US4936494/en.

Contradictions flagged against the prior sections: (1) The earlier Patent summary states the Federal Circuit "affirmed the invalidity determination," whereas the earlier Litigation summary explicitly flags lower confidence on whether the appellate court affirmed the '494 obviousness holding or only vacated the '399 on-sale-bar finding under Pfaff and mooted the alternative non-infringement ruling. That gap should be closed against the full text of 163 F.3d 1326; it does not affect the ownership analysis above, since neither disposition changes who owned the patent. (2) No substantive bibliographic conflict — the 1988‑08‑11 recording date and 1988‑08‑04 effective date in the prior summary match reel 004929/0536 as reported in the source record.

I'll verify the citing references and search for any additional prior art, prioritizing live sources.

Prior Art Analysis — U.S. Patent No. 4,936,494

Scope note: This builds on the previously generated bibliographic, claim, and litigation sections. I do not repeat them. Method and caveats first, then the reference-by-reference § 102 analysis.

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1. Method, sources, and two flags

What I actually searched. I re-pulled the patent record from https://patents.google.com/patent/[US4936494](/patent/US4936494)/en (the authoritative full text supplied in the prompt) and verified each citation against independent records: Google Patents full text (e.g. https://patents.google.com/patent/[US4721221](/patent/US4721221)), FreePatentsOnline (https://www.freepatentsonline.com/[4714181](/patent/4714181).html), and the litigation record (CourtListener / midpage / Casetext dockets for Weatherchem v. J.L. Clark).

⚠️ I did not query the USPTO's Patent Public Search (ppubs.uspto.gov) or PatentCenter directly in this session. The full texts I relied on are the USPTO-derived texts mirrored on Google Patents and FPO. If you need the examiner's actual citation sheet and any Rule 1.97/1.98 IDS filings for application 07/224,342, that requires PatentCenter file-wrapper access, which I have flagged rather than assumed.

⚠️ Date inconsistency in the instructions. The operating parameters state today's date is 2026-09-30 (and the fetched patent page is timestamped 2026-09-30T13:42Z), while the task prompt states April 26, 2026. I flag this rather than silently pick one; nothing in the analysis below turns on it.

Literal-ID caution (carrying forward the earlier rule). "4936494" resolves to unrelated records as well — e.g. JP 4936494 B1 (a Japanese patent) and non-patent identifiers such as EIN 99-4936494. Only U.S. Patent No. 4,936,494 is in scope. Likewise, the 113–154 "Cited By" entries (Gateway Plastics, Sonoco, J.L. Clark, Robbins, CSP Technologies, etc.) are later documents citing the '494 patent; they are not prior art to it and I exclude them from the § 102 analysis except where noted.

The § 102 critical-date framework that governs everything below

The '494 application was filed 1988-07-26. The pre-AIA statutes therefore sort the references as follows:

Per the earlier litigation section, the patent's own record date of invention is the filing date, 1988-07-26, with Weidman's actual invention in late May/early June 1988. That matters: US 4,693,399 (issued 1987-09-15) and US 4,714,181 (issued 1987-12-22) fall after the § 102(b) critical date and are therefore available only under § 102(a)/§ 102(e).

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2. The references cited on the face of the '494 patent (the examiner's citations)

The granted patent carries exactly four U.S. references, all "cited by examiner." Every one is a patent, so each is § 102 art as of its issue date, subject to the critical-date sorting above.

2.1 US 3,322,308 A — Foster (J.L. Clark Mfg. Co.)

Description. A one-piece molded plastic container cover with hinged closures — the seminal 1960s art in this line. Its lineage is easy to trace: the same inventor/company design patent, US D301,549 ("Container closure," Foster, J.L. Clark Mfg. Co., filed 1986-01-06, issued 1989-06-13), lists 3322308 first in its own cited references, and the reference is carried forward in J.L. Clark's later work (e.g. US 6,299,033, VerWeyst et al., "Snap-on container closure with hinged flap," which cites "3,322,308 5/1967 Foster").

⚠️ Confidence limit: I could not retrieve the full specification of US 3,322,308 in this session, so the disclosure characterization below is drawn from its title, its citation lineage, and the manner in which later art uses it. I will not assert structural details I have not read.

§ 102 anticipation assessment. Potentially relevant only to the generic elements shared by claims 1, 9, 13, 14 — a one-piece plastic body, a hinged closure/flap, and some form of latch. It cannot anticipate any claim as a whole because nothing in the record suggests it discloses the combination that carried the '494 patent: (i) a flat sealing land spaced radially inward from the skirt and joined to it by a thin end-wall portion, (ii) internal thread means engaging a threaded container mouth such that tightening generates normal-to-end-wall forces, and (iii) a plurality of reinforcing ribs extending below the end-wall portion radially between the land and the skirt, disposed on the inner skirt periphery at a multitude of relatively closely spaced locations. It is § 103 base art, not § 102 art, for this patent.

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2.2 US 4,693,399 A — Hickman et al. (Weatherchem Corporation) ← most relevant patent reference

Description. This is the '494 patent's own parent design and is expressly incorporated by reference into the '494 specification ("Both of such Letters Patent are incorporated herein by reference in their entirety"). Per the district court's construction of the '399 claims in Weatherchem v. J.L. Clark, the '399 cap discloses:

• a one-piece molded cap with a semicircular spooning opening on one side and shaker apertures on the other;
• two living-hinged flaps with cooperating latch/release structure;
• a thin cylindrical skirt with inward helical thread projections (avoiding the thick-threaded-skirt mass of the '4714181 Durkee design);
• a generally uniform wall thickness;
• an annular sealing ledge on the lower side of the end wall interior of the skirt, "having a flat surface extending radially a distance substantially equal to at least twice the nominal wall thickness of the cap" ('399 claim 13, as quoted at 937 F. Supp. 1262), plus a chordal land area between the spoon and shake sides whose lower surface is coplanar with the sealing ledge and adapted to support a paper/foil safety-seal liner ('399 claim 12).

§ 102 anticipation assessment — the pivotal point. For § 102, the reference must disclose every limitation of the claim as a whole, including all limitations carried in from the claims it depends from. The '399 patent discloses everything recited in independent claim 1's preamble and body except one element: the "plurality of reinforcing ribs extending below said end wall portion radially between said sealing land and skirt, said reinforcing ribs being disposed on the inner periphery of the skirt at a multitude of relatively closely spaced locations." That rib/anchoring element is the sole structural point of novelty on which the '494 claims were allowed, and it is absent from the '399 disclosure. Therefore:

• No § 102 anticipation of claims 1, 9, 13 or 14 by the '399 patent.
• Because claims 2–8 and 10–12 all depend from claims 1 or 9, the '399 patent cannot anticipate any of claims 1–14.
• One important near-miss worth flagging for the dependent claims: '494 claim 6 ("said land is spaced from said skirt by a distance at least equal to about twice the thickness of said wall portion") and claim 12 (same, in the two-mode variant) track the '399's own claim 13 recitation ("a flat surface extending radially a distance substantially equal to at least twice the nominal wall thickness of the cap") almost verbatim. That is powerful § 103 ammunition against claims 6 and 12 — and, because the district court treated the '399's ledge as being at the junction of the end wall and skirt while the '494 characterizes the '399 sealing zone as "substantially spaced inward from the inner wall of the cylindrical skirt" (see the '494 specification's background), there is a genuine claim-construction dispute over whether the '399's ledge is the claimed "relatively flat sealing land." If a tribunal reads them as the same structure, the anticipation analysis for claims 6 and 12 alone shifts materially. I flag rather than resolve that.

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2.3 US 4,714,181 A — Kozlowski et al. (Durkee Industrial Foods Corp.) ← most on-point issued patent for the stated problem

Description (verified against the FPO full text). A screw-on condiment cap with a bridge portion 32 crossing the circular end 22 and dividing the top into a large spooning opening 34 on one side and a sift-hole area 36 on the other; a large lid 38 and a smaller sift lid 40, each hinged to the bridge ribs; sift-lid plugs 42 that enter the sift holes; internal threads 30 mating with bottle threads 28. Key to the '494: the patent states that "the major bulk areas of the cap are of equal thickness, so that there is no large mass of plastic greater in one area than in any other area likely to cause distortion of the cap from cooling stresses following cap molding," while an annular flat land area 44 extends entirely around the periphery of the underside of the cap contiguous with the cap skirt 24 and presses an insert liner 16 against the bottle rim; bridge ribs 46 are "flush on the inside with the land area 44" and extend upward above the plane of the top surface to supply rigidity without a thick mass. The locking means for the spoon-hole lid is "a plurality of spaced-apart tabs on the underside of the lid means defining an interference fit."

§ 102 anticipation assessment. This is the closest issued patent to the '494 disclosure, and it maps onto several dependent claims — claim 2 (uniform wall thickness), claims 3 and 5 (planar exposed surface; spoon opening plus small apertures and two flaps), claims 9 and 10 (the two-mode cap with first and second hinged flaps and a uniform-thickness end wall), and arguably claim 7 (a planar sealing surface). But it cannot anticipate because the geometries are inverted:

1. Its land 44 is contiguous with the skirt, not "spaced radially inwardly from said skirt and connected to said skirt by an end wall portion";
2. Its ribs 46 run across the cap in a bridge and are flush with the land, not "extending below said end wall portion radially between said sealing land and skirt" at "a multitude of relatively closely spaced locations" on the inner skirt periphery;
3. Its interior surface over the projections is not recessed to hold thickness constant in the '494 sense (it does the reverse — it lets the ribs project above the top surface).

No § 102 anticipation of claims 1–14. This is nevertheless the single best § 103 partner for the '494 claims, because it independently teaches the underlying problem (mold-shrinkage distortion remedied by equal bulk thickness) and the underlying solution concept (a land-plus-rib stiffening structure inside a threaded cap).

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2.4 US 4,721,221 A — Owens-Illinois Closure Inc.

Description (verified against Google Patents). A molded beverage closure (injection- or compression-molded shell) with a soft organic sealing liner laid against the underside of the top panel and preferably compression-molded in situ from the container rim's perspective. Its distinguishing feature is "a downwardly depending annular flange whose inside diameter is only slightly greater than the outside diameter of the container rim… positioned within the closure radially inwardly of the inside of the closure skirt to define an annular space therebetween," which restrains the liner's outside diameter and lets the liner be molded small — i.e. an inwardly spaced annular wall (dam) inside a threaded skirt, optionally with radial recesses forming a dovetail lock. Embodiments are given for top-seal-only and top-plus-side-seal beverage packaging.

§ 102 anticipation assessment. This reference is pertinent to exactly one limitation family: claim 1's and claim 9's "relatively flat sealing land extending from the interior surface of said end wall and being spaced radially inwardly from said skirt and connected to said skirt by an end wall portion," and to claims 13/14's "sealing surface … spaced radially inward of the ribs… a circumferentially continuous annulus … lying in a flat plane." But the '221 flange is a liner-retention dam, not a container-mouth sealing land — the liner performs the sealing, and the container rim seals against the liner top, not the flange. It also has no opening, no hinged flap, no latch, and no ribs, since it is a linerless-tamper-band beverage closure rather than a dispensing cap. No § 102 anticipation of any claim 1–14. Its only real role is § 103: it shows that an inward-spaced annular land inside a skirt was known closure geometry.

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3. Second-tier references: the "Family Cites Families" citations

Google Patents lists four additional references in the family citation set (i.e. cited against the '494's foreign counterparts AU 33899/89, CA 1324590, GB 2221211, DE 3917057 C2, FR 2634738 B1). They are not on the U.S. face but are citable against the same disclosure. All four are § 102(b) art.

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4. The prior art that actually decided the patent: the Rosam II cap

This is the most important entry for your purposes and it is non-patent prior art, so it does not appear in any citation table on the patent.

What it discloses. Per the district court's findings: a screw-on spice cap whose sealing land is spaced inward of the skirt, with eight ribs extending between the sealing land and the skirt, on the inner periphery of the skirt, "(7) serving to stiffen the entire cap, thereby limiting the problems of ovality and flap latch release when the cap is screwed onto a container." The court found the Rosam II cap "fully discloses the use of stiffening ribs in the same manner, with the same peculiar geometry, and to achieve the same function as described in the '494 patent."

§ 102 analysis — with a caveat I want to state plainly. The district court held the asserted claims (9, 13, 14) invalid for obviousness under § 103, not anticipation, on the ground that Rosam II "meets all the limitations of the '494 patent claims except that it has two sprinkle openings instead of a sprinkle opening and a spoon opening," with the '399 patent supplying the spoon opening. Two observations follow:

1. Claims 1, 13 and 14 do not require a spoon opening. Claim 1 requires only "at least one opening," and claims 13/14 likewise recite only "at least one opening" / "a dispensing cap." If Rosam II in fact meets all other limitations — including the spaced sealing land, the internal threads, and the plurality of closely spaced radial ribs "providing an anchoring action" — then on its face Rosam II is a § 102(a)/(b) anticipation candidate for claim 1 (and arguably 13/14), not merely § 103 art. The only reason the district court's "except" clause mattered is that the asserted claims (9, 13, 14) were tried and claim 9 is the one that specifies spoon-versus-sprinkle.
2. This was never adjudicated, because Weatherchem asserted only claims 9, 13 and 14. So the § 102 question on claims 1–8 and 14 is open as a matter of the reported record.

⚠️ Confidence caveat: I am working from the reported opinions and summaries (CourtListener/midpage/Casetext reproductions), not the full 75-page district court opinion. The exact limitations the court mapped onto Rosam II, and whether the two-sprinkle-openings objection was applied to claims 13/14 as well as claim 9, should be confirmed against the full text of 937 F. Supp. 1262 at 1286–89 before anyone relies on this point. I flag it as an analytical observation, not a holding.

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5. Bottom line: § 102 anticipation, claim by claim

Net finding: Of the four references on the face of the patent, none anticipates any of claims 1–14. The two genuinely dispositive pieces of prior art for this patent are (a) US 4,693,399 — the same-assignee, incorporated-by-reference parent that supplies every element of the '494 claims but the radial rib array — and (b) the Rosam II cap, which supplies precisely the missing rib array with "the same peculiar geometry," which is why the patent was held invalid for obviousness in 1996 (affirmed 1998, as covered in the earlier sections).

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6. Explicit uncertainties

1. US 3,322,308's disclosure was not verified in full text this session; my mapping of it rests on title, assignee/inventor lineage and later-art citations. Treat it as a characterization, not a quotation.
2. US 4,722,221's inventor is not confirmed — Google Patents did not surface the inventor field in my retrieval, and I will not infer one.
3. CA 1,122,924's publication date (as distinct from its 1982-05-04 grant date) was not verified; the § 102(b) analysis holds either way, but the precise printed-publication date matters if the reference is ever cited formally.
4. The Rosam II prior-use date is not established by the sources I retrieved; it determines whether it is § 102(a) or § 102(b) art.
5. The full texts of 937 F. Supp. 1262 and 163 F.3d 1326 were not retrieved in full in this session (only extensive reproduced passages). The claim-6/claim-12 "twice the thickness" cross-reference to '399 claim 13 and the Rosam II limitation-by-limitation mapping should both be confirmed against the complete opinions.
6. The Federal Circuit's precise disposition of the '494 obviousness holding remains flagged from the earlier litigation section; it does not affect the prior-art identification in this section but does affect the weight to give the Rosam II analysis.
7. I did not access ppubs.uspto.gov / PatentCenter. To confirm the examiner's citation sheet, any IDS submissions, and whether the four face citations were accompanied by an examiner's search-note classification (B65D 47/08 et seq.), the file wrapper for application 07/224,342 should be pulled directly.

I'll ground the obviousness analysis in the actual prior-art references and the court's own § 103 findings. Let me verify key facts.

Good — I have the court's own § 103 reasoning. Let me verify the remaining prior-art references cited on the face of the patent and close the appellate-disposition gap.

Two gaps remain: the identity of the "Cribb patent" (US 4,545,508) and the Rosam design patent, plus confirmation of the appellate disposition.

Obviousness Analysis — U.S. Patent 4,936,494 under 35 U.S.C. § 103

Scope note. This section analyzes the '494 claims against the prior art of record on the patent's own Google Patents page — the four "Patent Citations" listed under "Citations (4)," the four "Family Cites Families" references, and the prior art discussed in the specification — together with the non‑patent (public‑use) art that was actually litigated. I do not repeat the bibliographic, litigation, assignment or NPE material from the earlier sections; where those sections flagged an open question, I close it below.

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0. Contradiction closed (and one residual gap)

The earlier Patent summary said the Federal Circuit "affirmed the invalidity determination"; the earlier Litigation summary flagged lower confidence on whether the '494 obviousness holding was affirmed or whether only the '399 on‑sale‑bar finding was vacated/remanded under Pfaff.

The retrieved opinion text resolves the '494 half of that conflict in favor of the Patent summary. The panel's own disposition language reads: "Because this court affirms the determination of invalidity, this court vacates those portions of the judgment granting a declaration of noninfringement of the '494 patent and dismissing Clark's counterclaim for a declaration of noninfringement of the '399 patent." That is an express affirmance of the § 103 holding on the '494 patent and a vacatur of the alternative non‑infringement holding as moot. Source: Weatherchem Corp. v. J.L. Clark, Inc., 163 F.3d 1326 (Fed. Cir. 1998) — https://storage.courtlistener.com/harvard_pdf/[760245](/patent/760245).pdf and http://www.worldlii.org/us/cases/federal/USCAFED/1998/202.html

Residual gap: the same opinion contains a section headed "A. The '399 Patent and the On‑Sale Bar" in which the panel itself applies Pfaff ("The only remaining question is whether the invention was ready for patenting…"). That reads as an affirmance-by-application rather than the vacate-and-remand the Litigation summary described. I could not fully reconcile the two accounts within this analysis and flag it as unresolved; it has no bearing on the § 103 analysis below, because the '494 half is squarely affirmed.

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1. Legal framework applied

The controlling framework is Graham v. John Deere Co., 383 U.S. 1 (1966) (scope and content of the prior art; differences between the prior art and the claims; level of ordinary skill; secondary considerations), as qualified by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (a combination is obvious where the improvement is a "predictable variation," a "known technique to improve similar devices in the same way," or the product of "identified, predictable solutions" to a known problem; a formal "teaching, suggestion, or motivation" is not required).

Admissions in the '494 specification are treated as prior art. The specification states that the spooning opening and shaking apertures "are substantially identical to corresponding parts disclosed and claimed in the '399 patent, supra," and expressly incorporates U.S. 4,693,399 "in [its] entirety." It further admits that the '399 cap "provide[s] a cylindrical skirt having a thin wall thickness and a helical, inwardly projecting thread form," and derives from that admission a design constraint: "the cap must provide a sealing zone within the cap which is substantially spaced inward from the inner wall of the cylindrical skirt." These are applicant admissions usable for both the prior-art and motivation prongs.

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2. Level of ordinary skill in the art (Graham factor 3)

Based on the references themselves and the specification's assumed knowledge (injection molding, sinkholes, time‑in‑mold, shrink-induced ovality, living hinges, helical thread projections vs. cut threads), a person of ordinary skill in the art at the July 26, 1988 filing date would be:

• a designer/engineer of injection-molded container closures, typically with a mechanical or plastics-engineering degree plus roughly 1–3 years of closure-design experience, or several years of equivalent shop/mold-design experience in that field;
• familiar with the standard trade-off between wall uniformity and cycle time, with the known remedies for shrink distortion (uniform nominal wall, freeze points, ribs/gussets), and with closure sealing schemes (skirt-adjacent lands, inward lands, liners, plug seals); and
• familiar with the art of living-hinge two-flap dispensing caps for condiments — the field in which both the '399 and '181 patents sit.

This is a modest level of skill, and both asserted and unasserted claims must be judged against it.

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3. The prior-art corpus on the page, and what each reference supplies

3.1 The four cited references (face of the patent)

3.2 The four "Family Cites Families" references

3.3 Non‑patent / public‑use prior art (the art that actually decided the case)

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4. The actual differences: what the '494 claims add to the art

Reading the granted claims against the above, the '494's asserted advance over its own prior '399 patent reduces to exactly two structural changes, which the Federal Circuit itself described:

"The '494 cap differs from the '399 cap primarily in the way the cap forms a seal with the container… an annular sealing surface (36) inside the cap's skirt (11)… Because the portion of the container's end wall (12) between the sealing surface (36) and the skirt (11) may deflect slightly when the cap is threaded tightly onto the container, the cap also includes a plurality of peripherally spaced, radially extending ribs (71)." — 163 F.3d at 1328–29

And the district court, as quoted by the Federal Circuit:

"The principal difference between the '494 patent and the '399 patent is the addition of the radial ribs… The function of these ribs is to stiffen the entire cap and limit flaps from popping open when the cap is screwed onto a container."

So the two differences are:

1. Relocation of the sealing land radially inward of the skirt (with a thin end-wall portion joining them), and
2. A plurality of closely spaced radial ribs below that end-wall portion, between the land and the skirt.

Everything else in claims 1, 9, 13 and 14 — one-piece injection-molded body, circular end wall, cylindrical skirt, internal threads, opening(s), hinged flap(s), latch means, sealing against the container mouth — is undisputedly in the '399 (and largely in the '181), which the '494 expressly incorporates.

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5. Combination A — the primary combination: '399 + Rosam II (renders claims 1, 9, 13, 14 obvious)

This is the combination that was adjudicated, and the Federal Circuit affirmed it.

5.1 Element chart

5.2 Motivation to combine (why a POSITA would have done it)

1. Same field, same problem, same class. Both are injection-molded, two-flap, screw-on caps for spice/condiment containers (B65D 47/08). KSR, 550 U.S. at 415 (familiar elements, known methods).
2. The problem was expressly identified in the art. The '399 patent's own background (as summarized by the Federal Circuit) states that disfigured/oval caps "rarely achieve a good seal," and that "disfigured oval flaps often pop open when the cap is screwed onto the container during manufacture." Rosam II had solved that exact problem by putting ribs between the skirt and the sealing ledge — and Mrs. Rosenstein testified that it worked. The '494's stated goal (prevent latch malfunction from end-wall deflection) is thus the same problem, addressed by the same known technique.
3. The '494 patentee's own admissions supply the bridge. The specification states that with the '399's thin skirt and helical projections, "the cap must provide a sealing zone within the cap which is substantially spaced inward from the inner wall of the cylindrical skirt." Having told the examiner why the land must be moved inward, the patentee cannot contend that moving it inward was nonobvious.
4. The ribs are the ordinary expedient for the resulting thin-wall deflection. Ribs/gussets spanning a skirt-to-inner-structure gap to rigidify a thin molded wall were old and well known in this exact art: '181 (ribs whose undersides are flush with the land), '508 ("Cribb") (triangular gussets from the skirt to a circular reinforcing projection), '221 ("ribs reinforcing said annular member against deformation"), and '280 ("reinforce and rigidify the annular lip"). KSR at 417: "a known technique to improve similar devices in the same way."
5. Finite, predictable solutions with a reasonable expectation of success. Stiffening a thin annular web with N radiating ribs is a predictable mechanical exercise; Rosam II demonstrated that as few as eight ribs sufficed. No new or unexpected result is obtained — the Federal Circuit so held.
6. No teaching away. The '399's statement that the flaps are "devoid of heavy stiffening ribs" concerns the flaps (to preserve the progressive "peeling" latch release), not the end wall; the '494's ribs are on the end wall, not the flaps. Weatherchem's "more than ten ribs are necessary" argument was a fact question resolved against it. The '280 stripping trade-off is a manufacturing consideration that a POSITA weighs and, at eight ribs on an 53/63 mm cap, plainly tolerates.

5.3 Claim 1 in particular — a fortiori

Claim 1 requires only "at least one opening" and a hinged flap, not a spoon opening. The district court found Rosam II differs from the claims only in having "two sprinkle openings instead of a sprinkle opening and a spoon opening." Claim 1, therefore, reads directly on Rosam II — making claim 1 obvious a fortiori, and, if the Rosam II caps were in public use or on sale before July 26, 1987 (the critical date), a serious § 102(b) anticipation candidate for claim 1 as well. The "millions per year" finding is strong evidence of pre-critical-date public use, though I have not independently dated Rosam II's first use, and Weatherchem itself was litigated as an obviousness (not anticipation) case on this reference.

5.4 Result

Under Combination A, claims 1, 9, 13 and 14 are obvious, and each of the dependent claims falls with them (see § 8).

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6. Combinations B–D — independent alternative routes (useful if Rosam II is disqualified)

If Rosam II were excluded (e.g., if Weatherchem's "25% unusable" attack had succeeded on operability or public-accessibility grounds), the same claims remain obvious on the printed prior art alone. These are independent alternative holdings, not cumulative add-ons.

Combination B — '399 + '221 (+ optionally '280)

• '399 supplies everything except the inward land and ribs.
• '221 supplies the inward land structure in a threaded one-piece injection-molded plastic closure: an annular flange depending from the underside of the top panel, positioned radially inward of the closure skirt, separated from the skirt and forming an annular space therebetween, with the container rim seating inside it — plus claim 20's express recitation of "ribs reinforcing said annular member against deformation."
• '280 supplies the teaching that vertical projections spanning the top wall and the annular lip "reinforce and rigidify the annular lip."
• Motivation: '221 states an express reason for placing the seal radially inward of the skirt (reducing liner diameter; enabling in-situ liner molding) and an express reason for adding ribs to the inner annular member (reinforcement against deformation). Combining that sealing architecture with the '399's two-flap dispensing end wall is the substitution of one known sealing arrangement for another in the same cap type, with predictability, on a line of caps that must remain thin-walled for molding economics. KSR at 416–17; In re Fout / In re Kemps line (substitution of known equivalents).
• Counter-caveat: '221's flange exists to dam a liner; the '494 eliminates the liner. That is a difference in purpose, not in structure, and the '494 claims recite no liner. The '221 geometry is nonetheless squarely on point as the claimed land-plus-annular-space-plus-reinforcing-ribs structure.

Combination C — '399 + '181 (for the uniform-wall and planar-top dependent claims, and for claims 9/13/14's "end wall contoured" limitations)

• '181 independently teaches, in a screw-on two-flap spoon-and-sift condiment cap: (i) equal wall thickness across the major bulk areas to avoid cooling distortion; (ii) a flat interior land pressing the seal against the bottle rim; (iii) reinforcing ribs flush with that land so rigidity is obtained without thick masses; and (iv) lids hinged on upstanding ribs giving a smooth closed top.
• Motivation: same problem ('181's stated objects: "free of dimensional distortions," "absence of large masses… likely to cause dimensional distortion"), same field, same cap type.
• Caveat I will not paper over: the '494 specification disparages '181 — but only its "relatively thick skirt having female thread grooves" and the resulting material/shrink problems. It does not disparage '181's uniform-wall or rib teachings, and a reference is prior art for all that it discloses, not only for the aspect the applicant chose to criticize. In re Lamberti; MPEP 2125.

Combination D — '399 + '181 + '508 ("Cribb")

Where Combination A is unavailable and the motivation is framed narrowly around ribs, '508 supplies triangular gussets connecting the skirt of a cheese/spice cap to the end wall, or to a ledge at the junction of the skirt and end wall, "to rigidify the entire structure." The district court found exactly that disclosure in '508. (An accused infringer would argue '508's gussets terminate at a projection near the aperture rather than at a land spaced inward from the skirt — a genuine structural distinction the '494's rib claims do not require be measured against; the ribs need only lie "radially between said sealing land and skirt.")

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7. Motivation to combine — consolidated rationale

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8. Dependent claims — claim-by-claim

Note that claims 1, 9, 13 and 14 were the assertions in Weatherchem; the district court's reasoning, quoted by the Federal Circuit, addressed claims 9, 13 and 14. Claims 1–8 and 10–12 were not asserted but are no stronger: claims 2–8 all depend from claim 1, which as shown is met by Rosam II save for the (absent) spoon-opening requirement.

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9. Counterarguments, and why they fail

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10. Secondary considerations (Graham factor 4)

• Commercial success: real and substantial (Flapper line; ~$1M/yr by 1988, ~$16M in 1995). But the district court found the success flowed from the '399 design elements (large spoon opening, latch design), not the inward land/ribs — so no presumption of nexus, and the evidence cannot rebut the strong prima facie case.
• Copying: not established as to the claimed structure (see above).
• Failure of others: no evidence credited.
• Unexpected results: not shown; the asserted "more than ten ribs" necessity was a fact question lost on the merits.
• Skepticism / industry disbelief — cuts the wrong way here: the record contains a July 23, 1986 Weatherchem internal memorandum in which a marketing manager indicated that at least some Weatherchem personnel "believed the Flapper was not patentable." That is evidence of the patentee's own contemporaneous view that the design did not rise to invention — the opposite of a secondary consideration supporting validity.
• Licensing / industry praise: no evidence located bearing on the land/rib feature specifically.

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11. Bottom line

The '494 patent is not a case of a crowded, unpredictable art requiring hindsight. It is a textbook KSR case: the patentee identified its own prior patent as the starting point, admitted the design constraint that pushed the seal inward, and solved the resulting thin-wall deflection with the single oldest and most predictable stiffening expedient in molded-plastics design — closely spaced radial ribs — which a commercial competitor's cap (Rosam II) had already used, in the same cap type, for the same purpose. A person of ordinary skill would have combined these teachings with a reasonable expectation of success.

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12. Caveats on sourcing and identifiers

1. Full text not retrieved for US 3,322,308, US 3,323,671 and CA 1,122,924; I characterize them from the record's title/assignee/date only and do not build any element of the analysis on them.
2. US 4,545,508 is listed on the Google Patents family record as assigned to Kraft, Inc. with the title "Plastic closure for grated cheese or the like," while the district court refers to it as "the Cribb patent." I did not verify the inventor of record; the citation is reproduced literally as it appears in each source and not harmonized.
3. US Design Patent 278,602 (the "Rosam I" cap) — I could not verify its issue date; my search on that identifier returned no result. The Rosam II cap's pre‑critical‑date status therefore rests on the district court's public‑use findings, not on the design patent's date.
4. Prior-art status of '221: issued 1988‑01‑26 — after the '399's issue but before the '494's 1988‑07‑26 filing. It is therefore available under § 102(a)/(e) and combinable under § 103(a), but not § 102(b) art.
5. Non-substantive date discrepancy: the source page header is timestamped 2026‑09‑30 while the task prompt states April 26, 2026. I have used neither date other than for citation recency; nothing in this analysis turns on it.
6. Contradiction closed / residual gap: as set out in § 0, the Federal Circuit's express language ("this court affirms the determination of invalidity… vacates those portions of the judgment granting a declaration of noninfringement of the '494 patent") resolves the earlier sections' disagreement in favor of the Patent summary as to the '494. The '399 on‑sale‑bar disposition remains the one point I could not fully reconcile from the retrieved text.

Sources: https://patents.google.com/patent/[US4936494](/patent/US4936494)/en · https://patentimages.storage.googleapis.com/7c/21/16/a1c6f3efff18d0/US4936494.pdf · https://patents.google.com/patent/[US4693399A](/patent/US4693399A) · https://patents.google.com/patent/US4714181 · https://patents.google.com/patent/US4721221 · https://patentimages.storage.googleapis.com/99/41/db/8d7ddc346c06ec/US4714181.pdf · https://patentimages.storage.googleapis.com/fc/ff/29/6a87febd41b235/US4721221.pdf · https://patents.justia.com/patent/4545508 · https://www.courtlistener.com/opinion/2250493/weatherchem-corp-v-jl-clark-inc/ · https://storage.courtlistener.com/harvard_pdf/760245.pdf · http://www.worldlii.org/us/cases/federal/USCAFED/1998/202.html · https://app.midpage.ai/document/weatherchem-corporation-v-j-l-760245