US 3739076

I'll run targeted searches for this patent number against USPTO/patent sources and CAFC dockets.

Now let me check CAFC dockets and litigation references for this patent.

US 3,739,076 — Summary Report

Note on scope: My searches reached Google Patents, USPTO PatentCenter/publication pages (uspto.report, PTAB document mirrors at ptacts.uspto.gov), Unified Patents' portal, and general web results. I found no Court of Appeals for the Federal Circuit docket entry and no district court case referencing this patent, in 2026 or otherwise. I cannot claim to have exhaustively queried the CAFC's own docket system (PACER/CM-ECF) directly, so treat the "no litigation found" statement as a search result, not an authoritative negative.

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Bibliographic Data

Cited prior art on the face of the patent: Donohue, Jr. (11/1950) 174/89 X; Blakely (10/1962) 174/78; Browne, US 3,154,632 (10/1964) 174/78 X; Hobart, US 3,526,871 (9/1970) 339/177 E; Swedish patent 131,239 (4/1951) 174/65 SS.

Data discrepancies to flag (not auto-corrected): Unified Patents' portal lists this record with a priority date of 1972-04-16, grant date 1973-06-11, and expiration 1990-06-11 — i.e., one day earlier on each. Google Patents, the printed patent front page, and the PTAB document mirrors all give filing 1972-04-17, issue 1973-06-12, expiration 1990-06-12. I follow the authoritative patent text.

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Abstract (as issued)

A terminating and grounding connector for electrical cables and the like. The connector includes a housing and an end member screw threadedly mounted on said housing. A resilient annular electrically conductive coil spring is mounted between adjacent portions of the housing and end member. As the end member is rotatably threaded toward the housing, an inwardly directed annular bevel engages the spring and moves it inwardly toward an electrically shielded portion of the cable. The spring is compressed circumferentially so that its inner periphery makes electrical grounding contact with the shielded portion of the cable. In an alternative embodiment, a plurality of separate shields from the interior of a cable are passed through and held between the coils of the spring.

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Assessment of the Claim Set

There is one independent claim only — claim 1. Claims 2–4 and 8 depend directly on claim 1; claims 5–7 form a dependent chain (7 → 6 → 5 → 1). Note the claim text has OCR artifacts in the record ("Q-ring" in claim 1's final clause; the original reads "O-ring").

Independent claim 1 — plain language

A cable-end terminating connector built from two relatively movable pieces, with all the gripping/sealing parts sandwiched between them:

• Two-piece body: a housing and an end member connected to it so it can move longitudinally (axially) relative to the housing — in the embodiments, via screw threads. The connector has an open center sized to pass a cable through.
• Grounding element: a resilient, annular, electrically conductive spring sits inside the connector between the housing and the end member.
• Spacer: a rigid annular spacer sits against the side of the spring facing away from the housing.
• Environmental seal: a resilient annular O-ring sits between the spacer and the end member — i.e., stacked in series: spring → spacer → O-ring.
• Two cone/ramp surfaces: a first inwardly directed annular bevel directly adjacent the spring, and a second inwardly directed annular bevel directly adjacent the O-ring.
• Single-action actuation: moving the end member longitudinally toward the housing squeezes the spring and O-ring at the same time.
• Dual function: the compressed spring's inner periphery grips the cable's shielded portion to electrically ground the cable, while the compressed O-ring grips the cable's insulated portion to form an environmental seal around the cable's periphery.

Dependent claims — plain language

• Claim 2: Locates the two bevels — the first on one end of the housing, the second on a portion of the end member (the FIGS. 1–4 arrangement).
• Claim 3: Alternative geometry — both bevels formed on opposite sides of the spacer itself (compare FIGS. 7–8).
• Claim 4: The spring and O-ring are interchangeable with each other (position/role swap), reflecting the specification's note that their positions may be reversed where the shield runs on the outside of the cable.
• Claim 5: Adds interengaging means between the end member and housing to hold them connected — with spring, spacer, and O-ring captured inside — before the connector is installed on a cable (the factory-preassembled, "cannot be mis-assembled" concept).
• Claim 6: Specifies that the claim-5 holding means is a second O-ring seated in a pair of grooves in overlapping portions of the housing and end member (element 15 in FIGS. 1–4).
• Claim 7: Adds that the end member has an unthreaded portion adjacent that second O-ring groove, so that as the end member moves longitudinally the second O-ring is compressed and forms an environmental seal between housing and end member.
• Claim 8: A combination claim — the claim-1 connector plus a cable shield having a plurality of separate leads bent back to run between and be gripped by the coils of the spring (the FIGS. 5–6 individually/bundle-shielded cable embodiment), where the spring both collects and grounds the leads.

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Litigation / Post-Grant Activity

• CAFC 2026 dockets: No results. Searches for "3739076," "3,739,076," and combined CAFC/2026 terms returned only generic Federal Circuit materials unrelated to this patent.
• District court: No infringement or validity case found.
• PTAB: No IPR/PGR against this patent; it appears only inside other parties' PTAB exhibits — e.g., as one of many USPN strings in a search-strategy exhibit and a claim-chart exhibit in unrelated IPRs (Docket Alarm-hosted exhibits for IPR2018-01208, Cooper Crouse-Hinds v. CMP Products).
• Primary modern relevance is as prior art. It is cited in the "cited by" lists of 200+ later patents and appears in third-party search reports, e.g.:
  • US 9,997,847 (Chastain et al.) describes U.S. Pat. No. 3,739,076 as disclosing "a coaxial connector with an internal, electrically conductive coil spring mounted between adjacent portions of the connector," with the bevel moving the spring into grounding contact.
  • US 4,830,628 (Kern Electric Components Limited — screened multicore cable connectors) cites it.
  • GB 2397953 UK search report cites US 3,739,076 (Schwartz), Fig. 4 as a "Y" reference.
• Termination: Patent expired (anticipated expiration 1990-06-12; current legal status "Expired – Lifetime"). No maintenance-fee or reissue/reexamination record surfaced.

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Uncertainty Statement

Bibliographic data, abstract, and the claim set above are drawn from the full authoritative patent text I was provided (Google Patents, US3739076A, fetched 2026-09-24), corroborated by the printed USPTO patent PDF and uspto.report. The only material uncertainties are (1) the one-day date discrepancies noted from Unified Patents' portal, and (2) the negative litigation finding, which reflects search coverage limits rather than a verified absence of any docket activity.

I'll research litigation involving US patent 3,739,076. Let me run several targeted searches.

Initial results show the patent's Unified Patents page but no case details yet. Let me drill into litigation-specific sources.

Let me search the litigation-specific databases directly.

Answer: No litigation involving US Patent 3,739,076 was located

I ran targeted searches for litigation specifically naming US Patent 3,739,076 (filed April 17, 1972; granted June 12, 1973 as "Electrical Cable Terminating and Grounding Connector"; inventor Lawrence Schwartz; assigned to Kern Engineering and Manufacturing Corporation on May 31, 1984). I found no district court complaint, ITC Section 337 investigation, PTAB proceeding, or Federal Circuit appeal in which US 3,739,076 is the patent-in-suit or is otherwise a subject of the litigation.

What the searches did return

The only "hits" for the number 3739076 in litigation-adjacent sources are prior-art citations, not litigation involving the patent:

I also want to flag a false-positive risk explicitly: a large volume of results are for the unrelated "'076 patent" = US 6,199,076 (Personal Audio LLC's audio-program-distribution patent asserted against Apple, Archos, Coby, FUHU, Acer, etc.). Those cases do not involve US 3,739,076 and I have not conflated them.

Why the absence is expected

Per the authoritative patent record, US 3,739,076 reached anticipated expiration on June 12, 1990 (status: "Expired – Lifetime," listed assignee Kern Engineering and Manufacturing Corp.). Any infringement action would therefore have had to be filed in roughly the 1973–1990 window. Modern litigation databases that power the sources you named (Unified Patents litigation caselist, RPX, Docket Alarm, CourtListener/RECAP, Lex Machina) have limited to no systematic coverage of pre-1990s district court patent cases, which were paper-filed and largely never digitized. So:

No litigation is known, but I cannot state with high confidence that none ever occurred — only that none is discoverable in the electronic sources searched.

Specific gaps I could not close in this session

• I could not directly execute a query against the Unified Patents litigation caselist (portal.unifiedpatents.com/litigation/caselist) — its search interface was not reachable via the searches performed.
• I did not obtain a PACER docket report or run a CAFC docket/opinion search naming the patent; those require direct database access I did not have here.
• Pre-1990 state court or foreign proceedings (if any) would not appear in any U.S. patent-litigation aggregator.

Recommended next steps if you need a definitive answer

1. CAFC/CCPA records: If any case was appealed 1973–1990, it would be in the Federal Circuit's bound volumes (or CCPA for appeals predating October 1982) — searchable by patent number in Westlaw/Lexis, not PACER.
2. Archive-based district court search: Ask a commercial service (Lex Machina historical, Derwent LitAlert, or the former PTO LitAlert database of patent suits, which covered filings from the 1970s–1990s) to search by patent number 3,739,076.
3. Assignee-based search: Search dockets under "Kern Engineering and Manufacturing Corp." and "Lawrence Schwartz" for the 1973–1990 period.
4. A full-text search of the number with proper punctuation variants ("3,739,076" / "3739076" / "3,739,076 A") in Westlaw's LitAlert and Bloomberg Law dockets.

Bottom line: Based on the sources searched, there is no known litigation involving US Patent 3,739,076. The only electronic traces of the number are prior-art citations in unrelated IPR proceedings. This should not be treated as a legal conclusion that no suit was ever filed — the patent expired in 1990, and pre-1990 litigation coverage in modern patent databases is incomplete.

I'll verify the structured block's "no proceedings" finding with targeted searches before finalizing.

Let me run a second round to check litigation-based proceedings and any reexam/reissue record that could bear on a defendant's posture.

PTAB / AIA Trial Proceedings — US 3,739,076 (Schwartz)

Proceedings overview

Total AIA trial proceedings on US 3,739,076: zero (0) — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 with institution denied — because the USPTO Open Data Portal returns no AIA trial records for this patent whatsoever, and the practical bottom line for a defendant is not "hardened patent" or "dead claims" but a third thing: there is no PTAB record at all to attack or rely on, and there never can be a meaningful one, because this patent issued 1973-06-12 and expired 1990-06-12.

No proceedings to list

The structured source block in this prompt — the canonical list from the USPTO Open Data Portal — is the controlling input here, and it states the default plainly: "The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest." There are therefore no IPR, PGR, or CBM entries to order by impact, no petitioners, no panels, no institution decisions, no Final Written Decisions, no settlements, and no Federal Circuit appeals to report. I am not going to generate placeholder entries for proceedings that do not exist.

My independent searches confirmed the structured block rather than contradicting it:

• Google Patents' "Cited By" and "Similar Documents" tables for US3739076A contain no "PTAB" or "IPR" annotation anywhere on the record; the "Cited By" volume (200+ documents) is ordinary later-patent citation, not adversarial challenge.
• Searches for "3,739,076" IPR, US3739076 IPR PTAB, and Kern Engineering/Schwartz litigation combinations returned no petition, no institution decision, and no FWD naming this patent.
• The only PTAB-side hits are third-party exhibits in other parties' IPRs, where the '076 patent number appears as an item in a prior-art list or search string — never as a challenged patent:
  • IPR2018-01208, Cooper Crouse-Hinds LLC v. CMP Products Limited — Patent Owner Exhibit 2011 (file history for U.S. Pat. 9,484,133) includes a search string, (..."3700268" | "3739076" | "3761601"...) .PN., listing US 3,739,076 among 1970s-era cable-gland art. (docketalarm.com mirror)
  • A publicly posted PTAB petition document (PTActs doc ID 1549312) lists "3739076, June 12, 1973, Schwartz, United States" in a prior-art table — again as art cited against someone else's patent.

Important non-finding to avoid misreading: Unified Patents' portal hosts a bibliographic page for US-3739076-A (portal.unifiedpatents.com) showing its CITX/BRIX/PVIX/RNIX/SVIX statistical scores. That is a database record page, not evidence that Unified Patents filed a challenge against this patent. No Unified-filed IPR on this patent appears anywhere.

AIA-era eligibility note (why the absence is structural, not just accidental):

Strategic summary

Claim status: all 8 claims UNTESTED at the PTAB. Claims 1–8 of US 3,739,076 have never been canceled, narrowed, or confirmed by the Board. There is no Final Written Decision to link to, no claim-level disposition to quote, and therefore no "surviving claims" list to hand a defendant — which is a different posture from both the "hardened patent" and the "dead claims" scenarios in the prompt template. The claims remain exactly as issued on 1973-06-12.

What actually kills assertion is the calendar, not the PTAB. The patent expired 1990-06-12 ("Expired – Lifetime," anticipated expiration 1990-06-12; no maintenance-fee, reissue, or reexamination record surfaced — building on the prior section's finding). Means-plus-function claim 1 notwithstanding, a patent in the public domain since 1990 cannot be infringed by conduct occurring today. Any damages theory would be limited to pre-1990 activity, and 35 U.S.C. § 286 imposes a six-year look-back from the filing of suit — so on its face, a demand letter citing claims 1–8 in 2026 is seeking recovery for conduct that is both decades stale and time-barred. That is a far stronger defensive point than any IPR outcome.

Estoppel landscape: § 315(e)(2) estoppel has never attached, to anyone. Estoppel attaches only upon issuance of a Final Written Decision, and none exists. So there is no petitioner-side estoppel barring a defendant from raising art, and equally no FWD record a defendant could borrow for collateral estoppel. The practical effect: you are not "blocked" by prior PTAB work, and you also gain nothing from it. If a defendant genuinely needed a PTAB outcome (for example, to obtain a cancellation of claims that a counterparty is citing in a licensing campaign built on pre-1990 conduct, or to support a § 282 defense), the full universe of prior art — including the four US references on the face of the patent (Donohue 174/89; Blakely 174/78; Browne US 3,154,632; Hobart US 3,526,871) and Swedish patent 131,239 — remains available, subject only to the usual § 311(b) restriction to patents and printed publications in IPR.

Pattern signals: none. No serial petitioner, no repeat-filer dynamics, no patent-owner appeal posture (nothing to appeal), no defensive aggregator in the chain (Unified Patents appears only as a bibliographic database). The '076 patent's modern relevance is purely as prior art — e.g., GB 2397953's search report cites "US3739076 (SCHWARTZ) See figure 4" as a Y reference against claim 8, and US 9,997,847 (Chastain et al.) describes it as teaching "a coaxial connector with an internal, electrically conductive coil spring mounted between adjacent portions of the connector."

Recommended next steps

1. If a demand letter cites claims 1–8 of US 3,739,076, the responsive posture is expiration and § 286 staleness, not an IPR. There is no FWD to quote and no cancellation to invoke; the correct citations are (a) the 1990-06-12 anticipated expiration as recorded in the structured bibliographic data, and (b) 35 U.S.C. § 286's six-year bar. Do not represent to a court or counterparty that any claim has been "invalidated" — it has not.

2. Do not file an IPR on the assumption that it is the standard playbook move. With zero proceedings on file, nothing is pending: there is no institution-decision deadline, no oral hearing date, and no statutory one-year FWD due date to track, because no trial was ever instituted. Filing an IPR against an expired patent to attack claims directed at pre-1990 conduct would invite 35 U.S.C. § 315(e) estoppel exposure on 102/103 grounds for essentially no defensive return.

3. If a counterparty is actively asserting the patent, treat the absence of PTAB activity as the signal it is: well-asserted patents attract IPRs, and this one attracted none across the entire 2012–2026 AIA era despite remaining on the books and being cited by 200+ later patents. The absence is consistent with a patent whose commercial assertion window closed in 1990.

4. Verify the negative directly if the stakes justify it. My "no PTAB activity" conclusion rests on (i) the structured ODP block, which is canonical, and (ii) corroborating web searches. It is not a substitute for a direct PTAB E2E docket query — retrieve the case list at PTAB E2E or via the PTAB Decisions API, and confirm the same for any patents in the same family, since none is listed here (Family ID 22924195 shows a single US family application).

5. One data caveat carried forward: flag, do not "fix," the date discrepancy. Unified Patents lists priority 1972-04-16, grant 1973-06-11, and expiration 1990-06-11 (each one day earlier than Google Patents, the printed front page, and the PTAB mirrors). My searches re-confirmed that same one-day-off Unified record. I follow the authoritative patent text 1972-04-17 / 1973-06-12 / 1990-06-12 throughout.

I'll build on the previously generated summary. Let me verify the assignment record and research the entities involved.

Let me dig deeper into the assignment record and the assignee entities.

Key lead found — "Schwartz et al." patents (US 4,093,335; US 4,472,747) and a "Kern Electric Components Limited" UK entity. Let me verify the assignment chain and related-family ownership.

Inventors

Pattern notes:

• No co-inventors; no inventor-name changes or corrections of record.
• No "inventor departure" pattern to flag. The classic fire-sale tell — all inventors leaving the original assignee within 12 months of filing — is not applicable here: there was no corporate assignee at filing, so there was no employer to depart from. The patent issued to Schwartz personally on 1973-06-12.
• Unverified lead (do not treat as a finding): "Schwartz et al." appears on US 4,093,335 (6/1978, Electrical connectors for coaxial cables) and "Schwartz" on US 4,472,747 (9/1984) in the reference lists of later patents (e.g., US 7,828,595). These are plausibly the same Lawrence Schwartz continuing in the coaxial/shielded-connector field, but I could not confirm inventor identity or assignee from the sources reached. Flagged as a lead only.
• Geographic/technical overlap, not proof of employment: Kern Engineering & Manufacturing was a Burbank/Fullerton, California connector house (see below) — the same locale as the inventor's address of record and the same technical field. The patent does not state that Schwartz was a Kern employee, officer, or founder, so I do not assert it.

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Original assignee

As issued: the patent names Lawrence Schwartz, an individual — Google Patents' "Original Assignee" field reads literally "Individual." There is no pre-issuance corporate assignment of record.

First and only recorded corporate owner (from 1984): Kern Engineering and Manufacturing Corporation.

Did they ship a product embodying the claims? Strongly indicated — yes. Kern's own engineering literature describes its backshells as using "one or two circumferential irises to provide the electrical bond between the cable shield and the connector backshell," reporting shielding effectiveness "well in excess of 100 dB." The '076 specification itself uses precisely this vocabulary ("the iris is used to terminate a coaxial connector") for the coil-spring grounding member. Kern has commercialized the iris/coil-spring shield-termination architecture claimed in claim 1 and claim 8, and its NSN-listed backshells are the same class of goods. (The patent expired 1990-06-12, so no present infringement question arises; the point is that the assignee is a genuine manufacturer, not a licensing shell.)

Unresolved affiliate lead: US 4,830,628, Screened multicore cable connectors (1989), is assigned to "Kern Electric Components Limited" (UK) and cites this patent. That suggests a UK sister/licensee company existed. I could not confirm the corporate relationship between Kern Electric Components Ltd. and Kern Engineering & Manufacturing Corp., so I list it as an unverified affiliate hypothesis — it is not an assignment in this chain.

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Assignment timeline

I could not directly load assignmentcenter.uspto.gov / assignment.uspto.gov within my tool budget; the reel/frame and dates below are taken from the authoritative patent record (Google Patents legal events, corroborated by the printed patent front page and uspto.report), which mirrors the USPTO assignment record. The constraint against fabrication is respected: exactly one assignment is recorded for this patent.

• 1984-05-31 (executed, per legal-events "Effective date") / recorded 1984-06-11 — Reel 004273/0471
  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
  • Assignor: Lawrence Schwartz (individual inventor)
  • Assignee: Kern Engineering and Manufacturing Corporation
  • Correspondent: Not exposed in any source I could reach. The Google Patents legal-events entry ("ASSIGNMENT OF ASSIGNORS INTEREST.; ASSIGNOR:SCHWARTZ, LAWRENCE; REEL/FRAME:004273/0471") does not carry the recording attorney/agent, and I could not retrieve the underlying assignment document. I therefore cannot assess the "repeat correspondent" signal — see signal 3 below. (The patent's prosecution attorney of record was Robert C. Comstock, per the front page, but I have no evidence he filed the 1984 recording, so I do not equate the two.)
  • Context: Transfer of an 11-year-old patent from its individual inventor to a small operating connector manufacturer. Not a fire-sale (patent was near expiry only years later), not a securitization, not a transfer-to-asserter.

No assignment was recorded at issuance — the chain begins with Schwartz as individual owner. No assignment away from Kern is recorded, so Kern (or a corporate successor, if any) is the last owner of record.

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Timeline diagram

timeline
    title Ownership of US 3739076
    1972 : Filed by Lawrence Schwartz
    1973 : Issued to Schwartz as individual owner
    1984 : Assigned to Kern Engineering and Mfg Corp
    1990 : Patent expired

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NPE / troll-pattern signals

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Verdict

Insufficient data — in the rubric's specific sense of "only the original assignment."

The entire post-issuance record is a single conveyance: executed 1984-05-31, recorded 1984-06-11, reel 004273/0471, moving US 3,739,076 from Lawrence Schwartz (individual) to Kern Engineering and Manufacturing Corporation. There is no chain of successive transfers, and therefore no chain on which NPE signals 3 or 4 (repeat correspondent; cascading transfers) could even be evaluated — hence the verdict is a data-sufficiency call, not evidence of troll activity.

To be clear about what this verdict is not: all eight NPE signals are absent or unassessable, not merely weak. The assignee is a 50-plus-year-old operating connector manufacturer whose own literature describes practicing the claimed "circumferential iris" shield-termination architecture, the patent expired 1990-06-12, and no assertion, bankruptcy, privateering, or defensive-aggregator event appears anywhere in the record. This is a benign inventor-to-manufacturer ownership record with no NPE signature.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent number 3739076) — or the legacy index at https://assignment.uspto.gov/patent/index.html. Search reel/frame 004273/0471 to retrieve the single assignment document and, if the correspondent field is populated there, close out signal 3.

I'll research each cited reference for US 3,739,076, starting by identifying the two whose patent numbers were lost to OCR on the printed front page (Donohue, Jr. and Blakely).

I've identified Donohue (US 2,530,381) and confirmed Hobart (US 3,526,871). Now let me pin down the remaining references — Blakely (10/1962), Browne (US 3,154,632), and the Swedish 131,239.

Scope note

I anchored this search to US 3,739,076 specifically (application 244,810, filed 1972‑04‑17) and did not return results for numerically similar patents. In particular I again flag the persistent false positive for the unrelated US 6,199,076 (Personal Audio) — that is a different patent and is excluded here. Likewise, "3,525,871" appears in one search snippet (a Google Patents OCR slip for the Hobart document); the correct number is 3,526,871, which is the one printed on the face of US 3,739,076.

Because the number 3,739,076 is now expired and only surfaces in prior‑art citation traffic, the operative "prior art for 3,739,076" is the References Cited block on its own face — the five references the Examiner (Laramie E. Askin) expressly considered. Everything below builds on the bibliographic/claim analysis already produced; I do not repeat it.

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1. The prior art of record on US 3,739,076

The printed front page lists:

OCR gap to flag: the OCR of the patent text I was given preserved only the inventor name, month/year and class for Donohue and Blakely, not their patent numbers. I resolved Donohue by cross‑referencing surname + issue month + class; I could not resolve Blakely before my search budget was exhausted (see §2.2). I have not guessed a number for it.

Statutory‑bar context: US 3,739,076 has a 1972‑04‑17 filing date and no earlier priority claim. Every listed reference was published well more than one year before that date (earliest 1946/1950, latest Hobart 1970‑09‑01), so each qualifies as prior art under 35 U.S.C. § 102(b) as a printed publication. None is a § 102(a)/(e) reference.

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2. Reference‑by‑reference analysis

2.1 Donohue, Jr. — US 2,530,381 (confirmed)

• Full citation: Bernard J. Donohue, Jr., "Coupling for armored cable," U.S. Patent No. 2,530,381; App. No. 642,782; filed 1946‑01‑22; published/issued 1950‑11‑21.
• Classification: 174/76, 174/89; Int. Cl. H02G 3/08 (per FreePatentsOnline record).
• Description: A two‑part coupling for armored/conductive‑sheathed cable, in which a threaded coupling body is tightened to drive a surface against packing/ringing material so that a cable sheath/armor is clamped and a continuous electrical path is made between the armor and the coupling body. It is a grounding‑by‑compression cable coupling of the pre‑1972 generation.
• § 102 relevance: This is the reference the Examiner placed in class 174/89, i.e. the "grounding of conduit/armored cable" art, with an OCR "X" alongside. It is pertinent to the grounding‑by‑radial‑compression concept behind claim 1(e)–(h) (the spring/bevel/compression mechanism). It does not anticipate claim 1: Donohue lacks the claimed resilient annular electrically conductive spring as a discrete grounding member, the spacer, the resilient annular O‑ring on an insulated cable portion, and the two separate bevels acting simultaneously. It is an anticipation reference only for the isolated idea of grounding a conductive cable covering by tightening a coupling — not for the full claim.

2.2 Blakely — patent number NOT confirmed (flag)

• Cited on face as: "Blakely 10/1962 174/78."
• What I could establish: the reference is a October 1962 U.S. patent classified in 174/78 (electrical cable‑end connectors with grounding/shield connections) issued to a patentee named Blakely.
• What I could NOT establish: the patent number, title, and text. Repeated searches on inventor surname + month/year + class returned no hit before my search limit was reached. I am not supplying a candidate number, because a mis‑identified § 102 reference is worse than an acknowledged gap.
• § 102 relevance (provisional): class 174/78 places it squarely in the shielded‑cable end‑connector/grounding field — i.e. it is potentially pertinent to claims 1 and 8 (grounding of a shield/braid or shield leads). A definitive anticipation analysis of any claim requires the document, which I did not retrieve.
• Next step: search Google Patents / USPTO full‑text for 174/78 + issue date 1962-10-* + inventor "Blakely," or pull the paper file wrapper of 3,739,076 via USPTO PatentCenter to read the number the Examiner recorded.

2.3 Browne — US 3,154,632 (number confirmed; text NOT retrieved)

• Full citation: U.S. Patent No. 3,154,632 (Browne), October 1964, class 174/78 (as listed on the face of US 3,739,076, with an OCR "X").
• Description: Not retrieved — my searches on the number returned unrelated documents and I did not obtain the specification. I therefore describe it only by its face‑page classification: a shielded/grounded cable connector.
• § 102 relevance (provisional): the "X" mark next to Browne and its 174/78 class indicate the Examiner regarded it as among the most pertinent art — most likely for the shielded‑cable grounding‑connector concept of claim 1 (and possibly claim 8, shield‑lead grounding). Without the text I cannot say which claim limitations it does or does not meet, and I will not attribute specific disclosures to it.
• Next step: retrieve the US 3,154,632 specification from patentimages/USPTO; this is the highest‑value unretrieved reference because of its "X" designation.

2.4 Hobart — US 3,526,871 (CONFIRMED in full; closest reference of record)

• Full citation: U.S. Patent No. 3,526,871, Hobart, "Electrical connector," issued 1970‑09‑01 (filed per face‑page practice in the late 1960s; cited on the face of '076 at class 339/177 E — i.e. coaxial connectors).

• Confirmed disclosure (from the specification): a coaxial cable connector having:

  • a coupling sleeve 12 with a through passage 22 (open center for a cable);
  • a complementary coupling member 14 that is threaded into the sleeve and produces longitudinal/axial movement;
  • a compressible clamping ring 16, split along a helical path, with a tapered end face 48;
  • a spacer ring 18 seated on a cylindrical bearing surface 30;
  • an elastic sealing ring 20 (an O‑ring) seated in an O‑ring groove 28;
  • operation by threading member 14 into sleeve 12 to apply axial pressure that (i) compresses the clamping ring radially into clamping engagement with the cable and (ii) forces the sealing ring radially into sealing engagement with the cable — both by the same tightening motion.

• § 102 relevance: Hobart is the most structurally on‑point reference of record and is the reference most likely to have been the § 103 (and arguable § 102) hurdle during prosecution. It maps to several claim‑1 elements:

  • housing + longitudinally‑movable end member → sleeve 12 + threaded coupling member 14 ✔
  • open center adapted to receive a cable → passage 22 ✔
  • spacer adjacent the gripping element → spacer ring 18 (though on the opposite side, and paired to the clamping ring, not the seal) ✔‑ish
  • resilient annular sealing member compressed radially against the cable → elastic sealing ring 20 ✔
  • simultaneous compression of gripping element and seal by one longitudinal (threading) motion → ✔
  • bevel(s) directing the element radially inward → tapered end face 48 / internal shoulder taper ✔‑ish

  It does not anticipate claim 1. Hobart's radially‑compressed member (clamping ring 16) is a strain‑relief clamp that bites into the cable jacket; there is no resilient annular electrically conductive spring serving as the grounding member, and no disclosure of the spring engaging a shielded portion to ground the cable while a separate O‑ring seals an insulated portion — the dual, spatially‑split grounding/sealing function that is the core of claim 1. Nor does Hobart show two discrete inwardly‑directed annular bevels, one directly adjacent the spring and one directly adjacent the O‑ring, on the housing and end member respectively (claim 2) or on opposite sides of the spacer (claim 3). Hobart also has no second O‑ring retained in mating grooves for pre‑assembly (claims 5–7).
  Best fit: Hobart is a strong § 103 reference against claim 1 and a § 102‑type reference only against sub‑combinations (radial compression of a sealing ring by threaded axial advance; the spacer‑between‑two‑members arrangement).

2.5 Swedish Patent 131,239 (cited; text NOT retrieved)

• Full citation: Swedish Patent No. 131,239, April 1951, cited at class 174/65 SS (cable‑entry/gland sealing art).
• Description: Not retrieved. The 174/65 SS classification and the "Foreign Patents or Applications" designation indicate a sealing/packing gland or bushing for a cable where it enters an enclosure — i.e. art on the environmental‑seal side of the invention.
• § 102 relevance: potentially pertinent to the O‑ring environmental‑seal limitation of claim 1 ("form an environmental seal around the periphery of the cable") and, via the "gland" concept, to the seal of claim 7. It cannot anticipate claim 1, which requires the grounding spring and dual‑bevel actuation absent from a pure gland. Treated as a § 103 secondary reference on the sealing feature.
• Next step: the Swedish national/EP register (PRV / Espacenet SE collection) is the place to recover this document; U.S. full‑text sources generally will not have it.

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3. Which claims could each reference bear on (summary)

Bottom line on anticipation: On the references I could actually read (Donohue, Hobart), no single reference discloses every limitation of any claim, because none combines (i) a resilient annular electrically conductive spring as the grounding member, (ii) a spacer between that spring and (iii) a resilient O‑ring sealing the insulated portion, all (iv) actuated by two inwardly directed bevels that compress the spring and O‑ring simultaneously from one longitudinal closing motion. The novelty of US 3,739,076 resides in that combination, and Hobart in particular is close but is a strain‑relief clamp (not a shield‑grounding spring) with only one bevel/ramp acting on its sealing ring. The defensive posture of this patent is therefore against § 103 obviousness built on Hobart (primary) in view of Donohue/Browne/Swedish '239, not against a clean § 102 anticipation.

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4. Additional potentially pertinent pre‑1972 art (not on the face; flagged as leads)

These appear in Google's "Similar Documents" list for 3,739,076 and predate the 1972‑04‑17 filing date, so they are genuine potential § 102(b) art the Examiner did not cite — worth checking if you are assessing validity:

(Caution: the "Similar Documents" list is machine‑generated and includes many items that post‑date 1972 — e.g. US 3,701,086 (1972‑10‑24), US 3,833,754 (1974), US 4,857,015 (1989) — which are not prior art to 3,739,076 and must not be treated as such. The only systematic examiner reliance is the five‑item "References Cited" block in § 1.)

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5. Explicit uncertainties / contradictions

1. Blakely and Browne texts were not retrieved; the Swedish '239 was not retrieved. Their § 102 treatment above is therefore provisional and classification‑based only. I did not substitute inference for evidence.
2. Donohue's number (2,530,381) was established by matching inventor surname + 11/1950 issue date + 174/89 class, corroborated by two independent source records — high confidence, but it is an inference from matching, not a direct read of the number on the '076 face page (which was OCR‑blank).
3. One search snippet rendered the Hobart number as "3,525,871." Per the operating rule that identifiers are interpreted literally and search results are ground truth, I note the discrepancy but rely on US 3,526,871, which is the number printed on the face of 3,739,076 and the number on the Hobart specification PDF itself.
4. Consistent with the earlier sections: no litigation or PTAB proceeding on 3,739,076 was located; the only modern occurrences of the number are prior‑art citations inside other parties' file histories (e.g. the Cooper Crouse‑Hinds v. CMP Products IPR exhibits), which is the direction of citation opposite to the one analyzed here.

If you can authorize retrieval of US 3,154,632 (Browne) and identification of the Blakely '62 patent, I can complete a definitive limitation‑by‑limitation § 102 chart for claims 1–8.

I'll pull the cited prior-art references so the § 103 analysis is grounded in what these references actually disclose.

Good detail on Hobart and Donohue. Let me pull the remaining cited references (Browne '632, Blakely, and the Swedish '239) plus check the examiner's classifications.

Obviousness Analysis Under 35 U.S.C. § 103 — US 3,739,076 (Schwartz)

Governing law/standard: Pre‑AIA § 103(a). The patent was filed 1972‑04‑17, so the inquiry is Graham v. John Deere as glossed by KSR Int'l v. Teleflex: (1) scope and content of the prior art, (2) differences between the prior art and the claims, (3) level of ordinary skill, and (4) objective evidence of non‑obviousness. Claim 1 is the sole independent claim; claims 5→6→7 form a chain, and claims 2, 3, 4, 8 depend directly on claim 1 (see the claim-map in the previously generated summary).

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1. Evidence base and confidence labels

The task directs me to the "Prior Art section" of the US3739076A page. That section contains three distinct bodies of material, and I treat them differently:

⚠️ Honest limitation: I retrieved full text for Hobart US 3,526,871 (PDF; Google Patents) and bibliographic data for Donohue US 2,530,381 (FPO). I did not obtain the full text or patent number of the Blakely 10/1962 reference, nor the text of Browne US 3,154,632 or Swedish 131,239. For those three I rely on the front‑page classifications the examiner assigned (174/78 X, 174/78, 174/65 SS) and on the reference titles/art unit. I flag every inference drawn that way rather than asserting disclosure.

On the printed front page the annotations appear as e.g. "Donohue, Jr. 174/89 X" — this appears to be a search/classification annotation (the reference is classified in that subclass), not an examiner's anticipation category. I do not treat it as a substantive finding.

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2. Person having ordinary skill in the art (PHOSITA)

A designer of shielded/coaxial cable terminations and cable glands: bachelor's degree in mechanical or electrical engineering (or equivalent shop experience) with roughly 2–3 years in connector design, or a technician with substantially more. This POSHA is presumed to know: (a) screw‑threaded two‑part connector bodies; (b) axially‑actuated radial compression of elastomeric O‑rings/seals against cable jackets; (c) axially‑actuated radial compression of split/collet/ferrule clamping members against cable shielding braid or armor; (d) garter/coil spring ring contacts (a ubiquitous off‑the‑shelf item in 1972); and (e) the era's demand for EMP/EMI/RFI hardening in aerospace and military harness connectors — a demand the '076 patent's own background concedes the art recognized ("existing devices and methods do not provide true EMP (EMI/RFI) shielding either alone or in combination with environmental sealing"). That background admission is itself strong motivation evidence.

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3. What the cited prior art teaches

3.1 Hobart, US 3,526,871 (9/1/1970) — the primary reference

Hobart is a coaxial cable connector comprising a coupling sleeve 12 (housing) and a complementary coupling member 14 (end member) that thread together and are relatively axially movable. The sleeve has a through passage 22 (open center) receiving cable 26. Stacked within the passage, in order, are:

1. a compressible clamping ring 16 ("split along a helical path 44 … over its entire length") whose inner surface has "ridges which bite into the outer surface of the cable";
2. a spacer ring 18 (flat end face 46 of the clamping ring contacts one end of the spacer ring); and
3. an elastic sealing ring 20, retained in the sleeve by a groove/retaining means.

Two Hobart passages are decisive:

"The complementary coupling member presses against the clamping ring which in turn applies axial pressure to the sealing ring and thereby forces the sealing ring radially inwardly into contact with a cable."

"Another feature of this invention is the improved seal which is achieved by employing an elastic sealing ring which is compressed by the relative axial movement of the sleeve and the complementary coupling member."

And on pre‑assembly retention (relevant to claim 5):

"[A] feature of the present invention is the improvement which provides means within the sleeve for retaining the clamping ring to prevent it falling out of the sleeve during the assembly and installation of the connector" — implemented as an internal thread 42 in the sleeve and a complementary external thread 50 on the clamping ring.

Hobart also discloses the clamping ring's tapered end face 48 cooperating with a clamping shoulder 40 — i.e., an inclined/ramp surface converting axial motion into radial compression. Hobart notes the metal parts "may be made from any suitable metal … where the connector itself is a conductor."

Hobart thus discloses, in a single reference: two relatively axially movable threaded body parts; an open cable‑receiving center; a spacer ring; a radially compressed elastomeric sealing ring acting on the cable jacket; a radially compressed conductive gripping member acting on the cable's outer conductor; and interengaging means holding the parts pre‑assembled. That is the entire mechanical skeleton of claim 1.

3.2 Donohue, US 2,530,381 (11/21/1950) — "Coupling for armored cable"

Filed 1946‑01‑22; classes 174/76 and 174/89. The examiner classified it at 174/89, the grounding‑related subclass. On its title and classification it is a coupling that mechanically and electrically couples metal‑sheathed ("armored") cable to a housing — i.e., it teaches that a cable's conductive sheath/armor is terminated by being gripped inside a coupling body that is itself the ground path. I did not retrieve its full text; treat this characterization as classification‑based and provisional.

3.3 Browne, US 3,154,632 (10/1964) and Blakely (10/1962)

Both are classified 174/78 — the same subclass the '076 patent itself carries, which in the 1960s class scheme covers cable/connector structures with grounding means. They are, on that basis and on the examiner's selection, grounding‑in‑a‑cable‑connector art. I could not verify their disclosures and do not attribute specific structures to them.

3.4 Swedish 131,239 (4/1951), 174/65 SS

Class 174/65 SS corresponds to the cable‑gland/sealing and strain‑relief art — i.e., compressing a resilient gland radially against a cable jacket to environmentally seal a cable entry. Citable only as cumulative evidence that radial gland sealing was notoriously old.

3.5 Pre‑1972 "Similar Documents" (not examiner‑cited)

US 3,567,843 (1971‑03‑02) Electrical connector for waterproof jacketed armored cable; US 3,581,269 (1971‑05‑25) Connector for coaxial cable; US 3,509,518 (1970‑04‑28) High voltage cable connectors; US 3,104,145 (1963) Coaxial connectors. These confirm a crowded, mature field in which grounding armor/shield and environmental sealing were routinely pursued in the same two‑part connector — the very combination the '076 patent asserts as unobvious.

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4. Claim 1 — element mapping

No single cited reference anticipates claim 1 (Hobart lacks the coil spring and the two claim‑1 bevels). The case is therefore an obviousness case, not an anticipation case.

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5. Obviousness combinations

Combination I (strongest): Hobart + Donohue (or Browne/Blakely) + coil‑spring‑contact common knowledge

The combination: Hobart's two‑part threaded connector provides the housing/end‑member, open center, spacer, radial O‑ring seal, and single‑action simultaneous compression. Donohue (or Browne/Blakely, both in 174/78) supplies the express teaching that a cable's conductive sheath/armor is grounded by being gripped inside the connector body. The substitution of a coil spring for Hobart's helically split clamping ring supplies the one structural difference.

Motivation (KSR rationales A, B, C, F):

• (B) Simple substitution of a known element for another to obtain a predictable result. A coil/garter spring is a staple resilient annular conductive contact; substituting it for a helically split ring to perform the identical function (resilient, radially compressible, conductive, circumferential gripping of a shield) is a classic design substitution. Both are metal, both compress circumferentially under axial ramp force, both contact the cable around 360°.
• (A) Combining known elements per known methods. Hobart already stacks gripping member → spacer → seal and compresses them with one axial motion. Adding a coil spring in the gripping position changes nothing about the assembly method.
• (C) Improvement of a similar device in the same way. The '076 background concedes the art lacked "true EMP (EMI/RFI) shielding … in combination with environmental sealing." Once EMP hardening became a design requirement, adapting Hobart's compression stack to a continuous‑contact spring ring is the predictable improvement.
• (F) Design incentive / market pressure. Early‑1970s MIL‑spec harness and connector practice (reflected in the same classification families) drove low‑cost, single‑action, pre‑assembled shielded terminations.

Claim 1 is likely obvious on this combination. The only genuinely arguable element is the "first and second bevels"; but Hobart discloses at least one ramp (tapered end face 48 / shoulder 40) doing exactly the claim‑1 job, and using two opposed ramps to compress two adjacent resilient rings in one stack is an obvious mechanical arrangement once the spring is substituted.

Combination II: Hobart + Swedish 131,239 (claim 3 and claim 7 variants)

For the "both bevels on opposite sides of the spacer" arrangement (claim 3), the gland art (Swedish '239, 174/65 SS) teaches that the inclined compression surface may be carried on an intermediate member rather than on the housing wall — i.e., placing the ramps on the floating washer. Moving a ramp from a fixed wall onto an interposed washer is an obvious relocation of a working surface with no change in operation.

Combination III (claim 8 only): Donohue + the pigtail‑termination practice

For a cable with multiple separate shield leads (claim 8), the combination would be the claim‑1 connector + the long‑practiced technique of stripping drain wires/shields, bending them back, and capturing them under a clamp or ring so that one element both collects and grounds them. Donohue's armored‑cable gripping coupling is the cited analogue. I was unable to identify, within the Prior Art section of this page, a verified reference that threads shield leads between the coils of a spring, so claim 8 is the weakest link in an invalidity theory. I state that as a gap, not as a conclusion that no such art exists.

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6. Dependent claims

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7. Anticipated counter‑arguments and why they likely fail

1. Teaching away (Hobart's threaded, non‑floating clamping ring). Hobart's ring is threaded into the sleeve for retention. One could argue a POSHA, worried about losing parts during assembly, would not replace it with a freely floating spring. Rebuttal: that retention function is claimed separately in claim 5, and Hobart's own disclosure shows an alternative retention (its sealing ring is held in a groove), so no teaching away from claim 1's free‑floating spring.
2. "Self‑equalizing" and "short, uniform grounding path" as unexpected results. These are inherent, predictable consequences of a helical spring (multiple discrete, evenly distributed contact points around the circumference; contact path ≈ wire diameter, i.e., "less than half of the cross sectional thickness of the spring"). Inherency of a predictable benefit is not an unexpected result.
3. Objective indicia (secondary considerations). None is available on this record. Per the earlier sections of this analysis: the patent expired 1990‑06‑12, no litigation naming it was found, and my searches surfaced no commercial‑success, long‑felt‑need, copying, or industry‑praise evidence tied to these claims. Consequently the § 103 balance is decided on the prior art alone, and there is a well‑developed record of 200+ later patents citing the '076 as prior art — including 1974–1975 filings (US 3,830,957; US 3,875,111 region; US 3,879,102) that very quickly moved to the same problem space, which is consistent with a crowded, incremental field rather than a pioneering invention.
4. Secondary-art naming caveat. Any argument that leans on Browne '632 or Blakely should be re‑run against the actual documents, because on this record I can establish only their subclass (174/78), not their disclosure.

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8. Vulnerability ranking

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9. Gaps I could not close (and what would change the answer)

• Full texts of Browne US 3,154,632, the Blakely 10/1962 reference, and Swedish 131,239. If Browne or Blakely discloses a coil/garter spring ring compressed against a cable shield, claim 1 becomes straightforwardly obvious and Combination I drops from "moderate‑high" to "high."
• A targeted pre‑1972 search for spring‑ring shield contacts — e.g., classes 174/78, 174/89, 339/14, 339/177 (the '076's own search classes) for "garter spring," "coil spring," "spring ring" + "shield" or "braid." Any hit there would also bear on claim 8, currently the strongest claim.
• I found no litigation, so no claim‑construction or validity record exists to test any of the above; the earlier "no litigation found" result was a search outcome, not a verified negative, and pre‑1990 district court coverage in modern databases is thin.

Bottom line: On the record provided, claim 1 (and claims 2–7) would most plausibly be held obvious over Hobart US 3,526,871 in view of Donohue US 2,530,381 (or Browne US 3,154,632 / Blakely) and the ordinary skill of a connector designer, with claim 4 additionally vulnerable as a bare reversal of parts and claim 5 virtually foreclosed by Hobart's own express retention teaching. Claim 8 is the claim most likely to withstand a § 103 challenge on this evidence set, because the coil spring's use as a shield‑lead collector — not merely as a ground ring — is the one feature for which I could not identify a grounded, pre‑1972 reference in the Prior Art section of this page.