US 1549311

I'll verify this patent number against live sources before summarizing.

Verification Summary — US 1,549,311

Search scope note: I searched for the literal number 1549311 / 1,549,311 in connection with shock absorbers and with CAFC 2026 dockets. USPTO Patent Center, Espacenet, and Google Patents records exist for this number as a 1925 patent. No CAFC 2026 docket, IPR, or appeal activity matched this number — the only non-patent hits for the bare string "1549311" were an unrelated Canadian pesticide registration document number and a Canadian trademark number. That null result is expected, as explained below.

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Bibliographic data

Uncertainty flags:

• No abstract exists. Abstract requirements postdate 1925. The only available "abstract" is the opening paragraph of the specification (quoted below). Do not expect to find a formal abstract in the original document.
• Minor OCR discrepancy on the filing date. The drawing caption text reads "Filed Jan.. 15, 1925," while the specification body and the bibliographic record both read January 13, 1925. The authoritative date is 1925-01-13; the "15" is an OCR artifact.
• The original specification contains significant OCR corruption (e.g., "A scribed consisting of…", "stung box", "dilferent"). I have interpreted these literally as text artifacts, not as different terms, but the underlying claim language should be confirmed against the patent PDF if exact quotation matters.

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Abstract-substitute (opening of the specification)

"My invention relates to hydraulic shock absorbers for motor vehicles and my object is to provide a relatively simple and inexpensive device of this character whereby shocks incident to a vehicle traveling over a rough road may be absorbed or modified to such extent as to be hardly noticeable to passengers riding in said vehicle. In carrying out the invention I employ a piston which acts to circulate oil or other suitable liquid, the flow being regulated by a valve which may be adjusted to retard the speed of circulation to accommodate the load acting on the shock absorber."

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Structure at a glance (for claim context)

Double-cylinder hydraulic damper mounted between chassis side bar A and axle B by universal joints 4 and 6. External cylinder 8 (caps 10, 12) contains a shorter internal cylinder 30, leaving top passageway 29, bottom passageway 31, and annular passageway 32a; cylinders joined by longitudinal tubes 36. Piston 38 (head 40, rod 42 through stuffing box 44) reciprocates in cylinder 30. Adjustment screw 16 is threaded through boss 14 in cap 10, locked by nut 18, carrying ball 22 (joint 4). Floating valve 26 rides on screw head 20 adjacent the top of internal cylinder 30. Member 48 on shoulder 50 carries tapered plungers 52 controlling relief chambers 54 through piston head 40. Filler opening 32 with dust cap 34 is deliberately set below the top of cylinder 8 to prevent overfilling.

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Independent claims — plain language

This patent has three claims, all independent (claim 2 does not depend from claim 1; each is drafted as "A shock absorber of the character described consisting of…"). Claim 1's preamble is OCR-corrupted but follows the identical pattern.

Claim 1 — Cylinder pair + piston + between-cylinder throttling valve + threaded mounting element

• An exterior cylinder and an interior cylinder, spaced apart so as to leave communicating passageways for circulating a liquid;
• a piston reciprocating inside the interior cylinder to circulate that liquid;
• a valve mounted between the cylinders to retard the liquid's circulation through them;
• an element threaded through one end of the exterior cylinder, with the valve operably mounted on that element; and
• means for connecting that threaded element to a vehicle (i.e., the ball 22 / universal joint 4 arrangement).
• In short: the broad genus — two spaced cylinders with circulation passages, a working piston, a flow-retarding valve sitting in the space between the cylinders, and a threaded rod through the cylinder end that both carries the valve and serves as the vehicle mount.

Claim 2 — Piston with relief chambers + plungers on a limited-movement member

• Exterior and interior cylinders spaced apart, leaving communicating liquid-circulation passageways;
• a piston reciprocating in the interior cylinder to circulate the liquid, the piston head being provided with relief chambers that admit a portion of the liquid;
• a member having limited movement on the piston stem; and
• plungers mounted on that member for expelling liquid from the relief chambers.
• In short: the valving-in-the-piston sub-invention — a floating plunger carrier that meters liquid through vertical relief passages in the piston head, alternately sealing and unsealing them as the piston strokes (elements 48, 52, 54). Notably, Claim 2 recites no external valve and no vehicle-mounting element; it is directed purely to the piston/plunger assembly.

Claim 3 — Full assembly: opposed mounting elements at both ends + between-cylinder valve

• Exterior and interior cylinders spaced apart, leaving communicating liquid-circulation passageways;
• a piston reciprocating in the interior cylinder with a stem extending through one end of the exterior cylinder;
• means at the outer end of the piston stem for connecting it to a motor vehicle (ball 46 / joint 6);
• a valve mounted between the cylinders to retard liquid circulation;
• an element extending through the opposite end of the exterior cylinder, the valve being operably mounted on it; and
• means for connecting the outer end of that element to the motor vehicle (ball 22 / joint 4).
• In short: the complete two-ended shock absorber — the narrowest of the three because it requires both the piston-stem vehicle connection at one end and the threaded valve-carrying element with its own vehicle connection at the other end, plus the between-cylinder metering valve.

Claim-drafting observation (interpretive, not authoritative): All three claims use "consisting of"-style language (closed transitional phrasing), which in modern practice would be read as closing the claim to unrecited elements — a significant narrowing relative to "comprising." I flag this because it materially affects scope if anyone were to construe these claims today. I have no authoritative claim-construction record for this patent, and none exists, as it has been expired since 1942.

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Litigation / docket status

No CAFC appeal, district court action, IPR, or post-grant proceeding involving US 1,549,311 appears in any source I searched, and none is plausible: the patent's term ran out on August 11, 1942, roughly 84 years ago, and it was never assigned away from the individual inventor. Any 2026 hit on the bare numeral "1549311" is a coincidental identifier in an unrelated database (the two I found were a Health Canada pesticide DACO reference number and a Canadian trademark record). I could not locate a copy of the original patent PDF's front page through search, so the assignee line ("Individual") and the exact inventor residence string are taken from the Google Patents bibliographic record rather than from a facsimile of the printed patent.

I'll search for litigation records involving US patent 1549311.

Let me try more targeted searches on litigation databases.

Litigation Search Results — US Patent 1,549,311

No litigation involving US Patent 1,549,311 was found.

Searches performed

• General web search for "US patent 1549311 litigation" — returned unrelated patent cases (Enzo Biochem v. Calgene, Network-1 v. HP) involving entirely different patent numbers.
• Search for "1549311" combined with infringement/lawsuit terms — returned only a Brazilian Superior Tribunal de Justiça docket (REsp 1549311) and a SEC insider-reporting CIK number, neither of which relates to US Patent 1,549,311.
• Search of the Unified Patents litigation portal and for docket/case references to the patent number — no results.
• Search for litigation involving the inventor, Charles F. Hutchings, and early shock-absorber infringement suits — no results matching this patent.

Why no litigation appears

The most likely explanation is chronological rather than substantive:

The patent issued in 1925 and reached the end of its term on August 11, 1942. Any infringement action on this patent would therefore have had to be filed between 1925 and 1942. Modern litigation databases (Unified Patents, PACER/CM-ECF, CourtListener, Darts-IP, Lex Machina) have essentially no systematic coverage of US district court dockets from that era; PACER's electronic records generally begin in the late 1980s–1990s, and the pre-1942 federal case law that has been digitized (e.g., via CourtListener's Harvard-merged PDFs) is a small, selective subset of reported opinions.

Caveats

• Because the relevant records are not digitized, I cannot affirmatively confirm whether a 1925–1942 infringement suit was ever filed concerning this patent. The absence of search hits is not proof that no such suit existed.
• If a suit did occur, it would not have produced a reported appellate decision that surfaced in these searches. Verifying would require archival research in the Federal Reporter/Federal Supplement digests for 1925–1942, USPTO assignment and litigation records, or the National Archives.
• Per the operating rule, I have interpreted the identifier literally as US 1,549,311 and have not substituted any similar number; results for other patents (e.g., the '930 or '931 patents appearing in the searches) are unrelated and are excluded.

Bottom line: Based on available online sources, no litigation is known involving US Patent 1,549,311.

PTAB / AIA Trial Report — US 1,549,311 ("Shock absorber")

Bottom line up front: There are zero AIA trial proceedings on this patent, and there is no realistic possibility of one ever being filed. US 1,549,311 issued in 1925 and reached anticipated expiration on 1942-08-11 — roughly 70 years before the first IPR was ever filed (the AIA trial regime took effect 2012-09-16). Web search surfaced no IPR, PGR, CBM, derivation, or ex parte reexamination record for this patent. The structured "PTAB proceedings on file" block (USPTO ODP, no AIA trials returned) is consistent with that.

Proceedings overview

Total AIA trial proceedings: 0 — no instituted, denied, settled, or terminated proceedings of any kind; consequently there are 0 claims invalidated, 0 claims sustained, 0 appeals. The defensive posture is not "hardened patent" and not "claims canceled" — it is "the patent is a 101-year-old expired artifact." Any demand letter or complaint asserting claims 1–3 of this patent is legally defective on its face (expired patent; no available damages window under 35 U.S.C. § 286), and there is no PTAB proceeding a defendant needs to consult because none exists.

No proceedings to report

Per the canonical structured list from the USPTO Open Data Portal, and confirmed by independent web searching (PTAB petition/decision repositories at ptacts.uspto.gov, CourtListener, and general web), no AIA trial proceeding has ever been filed on US 1,549,311. I did not locate any litigation, ITC investigation, ex parte reexamination (35 U.S.C. § 302), or interference involving this patent either. I am reporting this rather than populating the requested per-proceeding template, because fabricating a docket number, panel, or FWD disposition would be worse than an empty list.

Caveat on completeness: my searches are reliable for modern electronic records (1990s–present). I cannot rule out litigation or interference activity from the patent's 1925–1942 active term, because pre-war district court and Patent Office records are not fully digitized. That caveat is immaterial to today's question, since any such proceeding would be decades stale.

Why AIA trials are unavailable here (the real analysis)

• The patent is expired. Google Patents records "Anticipated expiration" on 1942-08-11 (a 17-year term from the 1925-08-11 grant under the then-governing statute). An expired patent cannot be infringed going forward, and § 286 caps damages recovery at six years before suit — no such window exists.
• IPR (§ 311 et seq.) requires a petition filed within one year of service of an infringement complaint, or by a non-served party at any time — but the Board has no reason and no ability to grant meaningful relief on a patent that expired in 1942. There is no live controversy to preserve.
• PGR (§ 321 et seq.) applies only to patents with an effective filing date on or after 2013-03-16. This patent's effective filing date is 1925-01-13 (Application No. 2,168 / US2168A).
• CBM review is limited to patents claiming a "financial product or service." A 1925 hydraulic automotive shock absorber is facially outside CBM eligibility.

Strategic summary

Claim status. US 1,549,311 issued with three claims, all apparatus claims: claim 1 (externally and internally spaced cylinders with communicating liquid-circulation passageways, a reciprocating piston, a valve between the cylinders, and a threaded element through one end cap with vehicle-attachment means), claim 2 (adds relief chambers in the piston head, a limited-travel member on the piston stem, and plungers for expelling liquid from those chambers), and claim 3 (adds the piston stem extending through one end of the exterior cylinder with vehicle attachment at both the stem end and the opposite-end threaded element). All three claims are UNTESTED at the PTAB — they were never challenged, and none was ever canceled. "UNTESTED" here is, however, a category with no defensive significance: a claim is not "sustained" because it survived a challenge that could not have been brought.

Estoppel landscape. There is no § 315(e)(2) estoppel to analyze — no petitioner exists, so no petitioner or privy is barred from anything. Symmetrically, a defendant today has no IPR-based shortcut and no FWD to point to. The defense is not "the PTAB canceled these claims"; it is a Rule 12(b)(6) / § 101-style threshold attack: the asserted patent expired on 1942-08-11, and any right to exclude ended 84 years ago. Practically, a defendant's IPR-art research on this reference set is unnecessary; the patent is better cited as prior art against someone else's modern shock-absorber or damper claims (its 1925-01-13 priority date gives it broad prior-art sweep in F16F9/00, F16F9/32, and F16F9/342 — the metering-pin throttling passage subclass assigned to it).

Pattern signals. None of the usual indicia appear: no serial petitioner, no Unified Patents or other defensive aggregator, no Patent Owner appeals to the Federal Circuit. Google Patents shows Individual as both original and current assignee, and the family consists of the single application US2168A. The "Similar Documents" list (e.g., US 1,468,652, US 1,519,451, US 1,485,243, US 1,595,330) is contemporaneous 1920s shock-absorber art, not assertion activity — it reflects shared classification, not a litigation cluster.

Recommended next steps

1. If you receive a demand citing US 1,549,311, do not build a PTAB strategy. Reply on expiration alone: the patent's term ended 1942-08-11 (source: Google Patents, US1549311A, "Anticipated expiration / 1942-08-11"), there is no § 286 damages window, and no injunction is available. Preserve the demand letter — asserting an expired patent is a fee-shifting and potentially state-law bad-faith data point under 35 U.S.C. § 285.
2. If the real target is a modern damper patent, pivot: this expired 1925 disclosure is prior art. Note the assigned classes — F16F9/00, F16F9/32, F16F9/34 and, notably, F16F9/342 (throttling passages operating with metering pins) — which map closely onto the tapered-plunger/relief-chamber structure described at claim 2 and the adjustable valve of claim 1.
3. Do not search for a Final Written Decision or Federal Circuit docket. There is none. The correct citations for this patent are the patent itself and the "PTAB proceedings on file" block returning no AIA trials; the PTAB E2E portal (ptacts.uspto.gov) and CourtListener return no proceeding tied to this patent.
4. Treat the absence of PTAB activity as expected, not as a signal about patent strength. The usual heuristic — "well-asserted patents eventually attract IPRs" — does not apply to a patent that expired before the challenged statutory regime existed. Do not read silence here as evidence of validity or as evidence of a hardened patent.

One drafting note for anyone quoting this patent: the USPTO/Google text is OCR-degraded. Claim 1 and claim 3 both open with a garbled phrase ("A scribed consisting of…" / "consisting of exterior and interior shock absorber of the character de-f4 cylinders…"), which reflects the original two-column print layout and the phrase "A shock absorber of the character described," not claim language. Quote only from a clean copy if you are putting claim text in a brief.

I'll verify the assignment record before reconstructing anything.

Assignment & Ownership Analysis — US 1549311 ("Shock absorber")

Method / caveat up front. I was not able to execute a live query against the Assignment Center API (no direct endpoint access in this session). The findings below rest on (a) the authoritative Google Patents record and its legal-events table, which I fetched, and (b) the documented coverage cutoff of the USPTO assignment database. Where I could not verify something, I say so rather than inferring.

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Inventors

• Sole named inventor. The specification and oath are signed in Hutchings' individual capacity ("CHARLES F. HUTCHINGS, a citizen of the United States, residing at San Francisco…"), and the front matter carries no assignee company.
• Signature witnesses: I. Z. Ray and E. R. Byxbee (witnesses only, not inventors or assignees).
• Unusual-pattern check: The flagged pattern — all inventors departing the original assignee within 12 months of filing — is not applicable. There was no corporate assignee at filing, so there was no employer to depart from. Under 1925 practice, an employed inventor's application was almost invariably accompanied by a recorded assignment to the employer; the absence of any such assignment here is consistent with an independent inventor working outside a corporate R&D organization, but the record before me does not affirmatively establish that.

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Original assignee

Individual — Charles F. Hutchings. Both Google Patents fields agree and are corroborated by the printed patent:

• Original Assignee: Individual

• Current Assignee: Individual (this is a carry-through of the original-assignee field, not evidence of a post-issuance transfer — see below)

• Entity type / line of business: None. No corporate entity is named; this is a sole-inventor filing, not a company asset. Assignee is therefore a natural person, which forecloses most of the standard NPE analysis (signal 1 requires an operating assignee to transfer from).

• Shipped a product embodying the claims? Unclear / no evidence. The specification describes the device as installed on a motor vehicle chassis ("Two or four shock absorbers may be applied to a vehicle, as preferred"), but the record contains no manufacturing entity, no product literature, and no commercial-sale evidence.

• Current status: The patent itself expired 1942-08-11 (anticipated expiration per the legal-status heading; "Expired – Lifetime"). The inventor's personal status (deceased, estate, etc.) is not determinable from the patent record. The underlying technology is a 1925 hydraulic lever-style shock absorber; the art field has long since moved on.

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Assignment timeline

There are no recorded assignments for US 1549311.

Stated plainly: the fetched Google Patents legal-events table for this patent contains only four events — application filed by Individual (1925-01-13), priority to US 2168A (1925-01-13), application granted / publication (1925-08-11), and anticipated expiration (1942-08-11). There is no assignment event, no reel/frame entry, no change-of-name, no security interest, and no license record. Target's "Publications," "Applications Claiming Priority," and "Family Applications" tables likewise show a single-member family with no conveyances.

For completeness, the Assignment Center fields would be:

• Execution date: none
• Recording date: none
• Reel/Frame: none — no reel/frame can be cited because no document was recorded
• Conveyance: none
• Assignor / Assignee: none
• Correspondent of record: none. No attorney or recording firm is captured, because no assignment instrument was ever filed.

Structural reason this result may be incomplete (important limitation, not a finding): the USPTO's online Patent Assignment Search database "contains all recorded Patent Assignment information back to August 1980"; assignments recorded prior to 1980 are maintained at the National Archives and Records Administration and are not in the online searchable index. US 1549311 issued in 1925 and expired in 1942 — 38 years before the online database's coverage begins. Therefore:

1. Any assignment executed in 1925–1942 would not appear in Assignment Center regardless of whether it happened.
2. Whether an instrument was recorded in the USPTO's pre-1980 record books (the old Liber volumes) is not verifiable through the sources available to me, and I decline to assert either that one exists or that none exists.
3. Given the patent expired in 1942, no post-1980 assignment could have been recorded against a live patent; any post-1980 entry would be a late or corrective recordation only.

I searched for corroborating coverage (assignment-search literature, inventor-name searches, court records) and found nothing linking this patent to any subsequent owner, litigation, or portfolio.

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Timeline diagram

timeline
    title Ownership of US 1549311
    1925 : Filed by Charles F Hutchings
         : Patent issued Aug 11
    1942 : Patent term expired
         : No assignments of record

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NPE / troll-pattern signals

Every signal is assessed against the same evidence base: zero recorded conveyance instruments, one individual inventor/owner, patent expired 1942.

1. Shell-entity transfer — Not present. No assignment exists at all, so there is no transfer from an operating assignee to a licensing LLC. There is no "IP / Patents / Holdings / Ventures" successor, no registered-agent address, and no single-purpose LLC anywhere in the record. There is no reel/frame to cite because no instrument was recorded.

2. Known asserter in the chain — Not present. The only named owner is Charles F. Hutchings, an individual. No assignee in the chain matches Acacia, Marathon Patent Group, Intellectual Ventures, IPNav, Wi-LAN/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. This is unsurprising: the major NPE entities on that list are post-2000 constructs, and this patent was expired and in the public domain for roughly six decades before any of them existed.

3. Repeat correspondent across the chain — Not present. No correspondent of record exists, because no assignment was filed. There is no attorney name and no firm to check against Unified Patents / RPX / Patent Progress assertion lists.

4. Cascading transfers — Not present. Zero transfers, therefore zero chained LLCs and no shared correspondent address.

5. Pre-litigation transfer — Not present. No infringement suit naming this patent was surfaced, and no pre-suit assignment exists. The patent expired 1942; there is no live enforcement window.

6. Bankruptcy fire-sale — Not present. No corporate assignee ever held the patent, so there is no Chapter 7/11 estate to sell from. (Contrast the Kodak / Nortel / Polaroid-style fact patterns, all of which require a corporate owner.)

7. Privateering — Not present. An operating company would first have to own the patent in order to funnel it to an NPE; no such owner or transfer appears.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at natural expiration.

Net: 0 of 8 signals present. This is not a case of "signals hard to read" — it is a case of the evidentiary prerequisites for all eight signals being absent. Nothing resembling an assertion chain exists in the record.

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Verdict

Insufficient data (no records, or only the original assignment)

Justification. The only ownership facts of record are the original individual filing by Charles F. Hutchings on 1925-01-13 and issuance on 1925-08-11 (US 1549311); there are no reel/frame entries of any kind, and no assignment, license, security interest, merger, or change-of-name. None of the eight NPE signals is supported, because each presupposes at least one recorded conveyance, and the patent — a 1925 hydraulic shock absorber — expired 1942-08-11, roughly 38 years before the USPTO's searchable assignment database begins coverage in August 1980. Accordingly this is Insufficient data, not "Operating-company assertion" and certainly not an NPE call: there is no asserting party, no litigation, and no successor owner to analyze. The residual uncertainty is archival rather than analytical — if a pre-1980 Liber recordation exists, it lives at NARA and outside the online Assignment Center.

Verification links:

• USPTO Patent Assignment Center (search by patent number 1549311): https://assignmentcenter.uspto.gov/
• Legacy Assignment Search (AOTW, coverage Aug 1980–present): https://assignment.uspto.gov/patent/index.html
• Google Patents record with legal-events table: https://patents.google.com/patent/US1549311/en
• Pre-1980 assignment records (National Archives and Records Administration): https://www.archives.gov/

Note on the instruction to "stop after this section" where no records exist: I have completed the timeline diagram, signal table, and verdict because the verdict schema you supplied explicitly defines an "Insufficient data (no records, or only the original assignment)" outcome. No assignment has been fabricated to populate any field.

I'll search for the USPTO record of US 1,549,311 and its cited prior-art references.

USPTO record verification — US 1,549,311

I was able to confirm the bibliographic identity of the target patent in the available record (Google Patents' rendering of USPTO/Espacenet data), literally as US 1,549,311 A. No substitution or auto-correction of the number was made, and no results for the many near-neighbour numbers that appeared in search (e.g., 1,549,905; 1,541,392; 1,549,311's Brazilian REsp 1549311; the '930/'931 patents) were used.

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Critical finding on the citation question

The authoritative full text of US 1,549,311 contains no "Patent Citations," no "References Cited," and no "Cited By" list.

I checked the complete document text supplied as authoritative, plus targeted searches for US patent 1549311 shock absorber Hutchings USPTO cited references, "1549311" patent prior art citations, and patents.google.com US1549311A cited by references. None returned a citation table for this patent. The only reference-type content on the record is a machine-generated "Similar Documents" list, which Google Patents derives algorithmically from classification/text similarity — it is not an examiner or applicant citation list.

Additional reasons to expect a genuinely empty citation set:

• The specification itself contains no discussion of prior art — no "Prior art" heading, no reference to any earlier patent or publication anywhere in the description.
• The patent issued in 1925, decades before the modern front-page citation format was systematized; Google Patents' data for patents of this vintage frequently has no captured examiner citation list.

I therefore cannot report "each patent citation for 1549311" as requested, because the record as published discloses none. Anyone asserting otherwise would be inventing citations. This is a hard limitation of the record, not a research shortcut.

Contradiction to flag

The task presupposes that a citation list exists ("Look at each patent citation for 1549311"). The authoritative document contradicts that presupposition. I flag this explicitly rather than fabricate references to satisfy the framing. I also note the previous litigation section in this analysis concluded the patent expired 1942-08-11 and had no corporate assignee — consistent with the thin citation record and lack of enforcement history.

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What can legitimately be evaluated as prior art

Because there are no citations, the only defensible thing to analyse is the "Similar Documents" set. Before doing so, one filter must be applied: under the law in force at the 1925 filing date (R.S. § 4886, the pre-1952 statute — not the modern 35 U.S.C. § 102 with its § 102(e) "secret prior art" provision, which did not exist), an anticipating reference must be a patent issued, or a printed publication dated, before the invention date / 1925-01-13 filing date. Critically:

• 19 of the 24 "Similar Documents" were published from 1926 to 1981 — decades after the filing date. Under any § 102 theory these are categorically not prior art to US 1,549,311 (e.g., US 3,117,800 (1964); US 3,062,331 (1962); US 3,297,312 (1967); US 4,251,088 (1981); US 2,410,992 (1946); US 1,970,403 (1934); US 1,868,912 (1932); US 1,792,695 (1931); US 1,615,326 (1927); US 1,635,284 (1927); US 1,605,249 (1926); US 1,595,330 (1926); US 1,572,060 (1926); GB 829,891 (1960)). The fact that a 1964 patent appears in a "similar documents" list for a 1925 patent is itself proof that the list is a similarity artifact, not a citation set.

• Only five documents in the list predate 1925-01-13 and are therefore even eligible as § 102 prior art:

Honest limitation on this analysis

I did not verify the actual disclosure of these five references within the available search budget, and I will not fabricate claim-by-claim anticipation findings. Based on their titles, dates, and USPC/CPC placement they are fluid-actuated shock absorbers of the same era as US 1,549,311, which makes them the only plausible § 102 candidates — but I cannot say with confidence which, if any, discloses each of the novel elements this patent actually claims. Verifying that requires pulling each of the five full texts (patentimages PDFs) and charting them against the claims.

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The claims that would need to be charted (reconstructed)

The OCR of the claim set is garbled (claim 1 reads "A scribed consisting of…"; claim 3 contains a duplicated fragment "…shock absorber of the character de-f4 cylinders…"). Reconstructing from context, the three claims are:

1. Claim 1 — Exterior + interior cylinders spaced apart leaving communicating passageways for liquid circulation; a piston reciprocable in the interior cylinder; a valve mounted between the cylinders to retard circulation; a threaded element passing through one end of the exterior cylinder upon which the valve is operably mounted; and means connecting that threaded element to a vehicle.

   • The load-bearing novel element is the adjustability: the threaded screw 16 lets the retardation be tuned "to accommodate the load," with the express proviso that the screw is never lowered enough to seat valve 26 on the internal cylinder. The five pre-1925 references would need to be checked specifically for (a) an inter-cylinder floating valve and (b) a threaded, vehicle-connected adjuster acting on that valve.

2. Claim 2 — The cylinder/piston combination plus relief chambers in the piston head (54), a member (48) with limited movement on the piston stem, and tapered plungers (52) on that member for expelling liquid from the chambers.

   • This is the most structurally specific and least likely to be anticipated; a pre-1925 reference would have to disclose the limited-travel member + tapered plunger/port valving arrangement.

3. Claim 3 — The full combination: piston stem through one end of the exterior cylinder with vehicle-connecting means, plus an adjuster element extending through the opposite end with the inter-cylinder valve mounted on it and its own vehicle-connecting means (the two universal joints 4 and 6).

Bottom line: US 1,549,311 has no patent citations on its face, and the "Similar Documents" list is not a prior-art citation set — 19 of its 24 entries post-date the patent by up to 56 years. The only genuine § 102 candidates are the five pre-1925-01-13 references tabulated above, led by US 1,519,451 A (1924-12-16), US 1,487,524 A (1924-03-18) and US 1,468,652 A (1923-09-25). Definitive anticipation mapping to claims 1–3 would require retrieving and charting those five full texts, which I have not done and will not guess at.

I'll analyze the prior art listed on this patent's page, but first I need to verify which of those references actually qualify as prior art against a January 13, 1925 filing — and get their substance. Let me pull the candidate references.

I have partial data. Let me pull the remaining pre-1925 references and more detail on the two most substantive candidates.

Obviousness Analysis — US 1,549,311 (Hutchings, "Shock Absorber") under 35 U.S.C. § 103

0. Data-integrity flags before the analysis

Per the operating rules, I am flagging inconsistencies rather than papering over them:

1. Date discrepancy. The task header states "Current Date: April 26, 2026," while the session metadata gives 2026-09-29. This does not affect an analysis of 1925-era art, but the dates are inconsistent and are noted here.
2. "Prior Art section" of the page. The Google Patents page for US 1,549,311 does not contain an examiner-citation table or an "Citations" list. The only prior-art-like content is (a) the machine-generated keyword field — liquid, piston, shock absorber, cylinder, valve — and (b) the "Similar Documents" list. "Similar Documents" is a similarity ranking produced by Google, not a list of references cited against the patent. Every combination below therefore has to be built from that list, with the caveat that none of those references is shown to have been before the 1925 examiner.
3. Full texts not retrievable in this session. I recovered bibliographic data and partial text for several of the listed references, but not the complete specifications of all of them. Where I am inferring disclosure from title/classification rather than reading the text, I say so explicitly. I am not asserting disclosure content I could not verify.

This last point matters: a defensible § 103 rejection requires element-by-element quotation from each reference. What follows is the framework and the strongest candidate combinations, with confidence levels marked.

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1. Threshold gate: most of the "Similar Documents" are not prior art

US 1,549,311 was filed January 13, 1925 (application US 2,168) and granted August 11, 1925. This is a pre-AIA patent, so § 102(a)/(b)/(e) and § 103(a) apply as they existed before the AIA.

• § 102(b) art: printed publication or US patent more than one year before filing → before January 13, 1924.
• § 102(a) art: patented/published before the applicant's invention date. Hutchings' invention date is unproven, so § 102(a) art can only be relied on conservatively.
• § 102(e) art: "a patent granted on an application for patent by another filed in the United States before the invention thereof by the applicant." This is the key route — a reference that published after Jan. 13, 1924 can still be art as of its US filing date, provided that filing predates Hutchings' invention date.

Applying that screen to the 25 documents in the "Similar Documents" list:

Consequence: of the 25 listed documents, only five are even arguably available, and only three are clean § 102(b) art. Roughly 80% of the page's "Prior Art" list is chronologically impossible to assert against this patent. Any obviousness rejection must be built on Reynolds '923, Gruss '793, Storey '652, with optional § 102(a)/(e) supplementation from Harris '451 and '524.

This is the single most important finding of this analysis, and it is one that a mechanical application of the Google Patents page would miss.

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2. The claims, decomposed

Claim 1 (OCR-garbled opening read as "A shock absorber of the character described consisting of…"):

Claim 2: elements 1.1–1.2 plus relief chambers (54) through the piston head admitting liquid, a member (48) with limited movement on the piston stem (restricted by piston head 40 and shoulder 50), and tapered plungers (52) on that member for expelling liquid from the chambers.

Claim 3: essentially claims 1 + 2 with the stem passing through one end of the outer cylinder (stuffing box 44 in cap 12) and the threaded adjusting element through the opposite end, each end carrying a vehicle-connecting means.

Three observations on claim construction that bear directly on § 103:

• "Consisting of" is a closed transition. All three claims use it. That excludes unrecited elements and, for § 103 purposes, means a combination need only supply the recited set — but it also means the claims are narrow and easily designed around, which cut against a broad obviousness sweep.
• Claim 1 recites no piston rod, no stem, no second attachment point. Element 1.7 is satisfied by any connection of the threaded screw to a vehicle.
• The claim 1 "valve … between the cylinders" need not be a throttling/proportioning valve. In the spec the floating valve 26 is at the upper end of the inner cylinder and it is actually the pressure-responsive plate that is pushed down onto the screw head 20 by liquid pressure. A check valve or spring-seated relief valve seated at the inner-cylinder mouth would on its face meet 1.4/1.6.

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3. Person of ordinary skill in the art (POSITA)

Circa January 1925: a mechanical engineer or experienced automotive-suspension mechanic with a working knowledge of (i) hydraulic damping by forcing oil through a restricted orifice, (ii) twin-tube vs. single-tube hydraulic damper architecture, (iii) spring-loaded and adjustable bleed/bypass valves, and (iv) the standard practice of attaching such units between frame and axle by ball-and-socket (universal) joints. No advanced degree required. This POSITA is presumed to know the entire body of contemporaneous shock-absorber art — which by 1925 was large and crowded.

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4. Scope and content of the qualifying prior art

4.1 Verified

US 1,468,652 A — Storey, "Shock absorber" — filed 1918-10-11, granted 1923-09-25, app. US 257,710; IPC B60G13/08. Verified bibliographically via FreePatentsOnline (https://www.freepatentsonline.com/1468652.html) and the Google Patents citation table. Clean § 102(b) art. Full text not retrieved in this session — I can confirm title, inventor, dates, and classification (vehicle suspension / fluid damping), but I will not assert its internal disclosure. Given its 1918 filing date and B60G13/08 classification it is a vehicle hydraulic/fluid shock absorber, but the element-by-element mapping must be verified against the specification and drawings.

US 1,135,923 A — Reynolds, "Shock-absorber" — filed 1914-03-17, granted 1915-04-13. Verified via Google Patents citation table. Clean § 102(b) art. Earliest qualifying reference; full text not retrieved.

US 1,446,793 A — Gruss (Roland M.), "Shock absorber" — filed 1922-02-06, granted 1923-02-27. Verified via Google Patents citation tables. Clean § 102(b) art. Full text not retrieved.

US 1,519,451 A — Harris (Albert L.), "Shock absorber" — priority/filed 1923-10-08, granted 1924-12-16. Verified via Google Patents citation table. § 102(e) art as of its Oct. 8, 1923 US filing date (assuming Hutchings invented after that date — very likely, given his Jan. 1925 filing).

US 1,487,524 A — "Shock absorber" — published 1924-03-18 (listed on the page; full bibliographic data not independently retrieved). § 102(a)/(e) only.

4.2 Additional art I located that is not on the page's list but is squarely relevant and available

I am flagging these separately because the task directs me to the page's Prior Art section, but omitting them would give a false picture of the 1925 state of the art:

US 1,494,135 A — Robison & Merkell, "Shock Absorber for Use on Automobiles" — filed 1923-08-31 (Ser. 660,316), granted 1924-05-13. Text retrieved (https://patentimages.storage.googleapis.com/ff/0c/ca/f322578c1e470a/US1494135.pdf). Discloses, in terms remarkably close to claim 1:

• an outer cylindrical casing 1 and an interior cylinder 4 mounted in and between the caps and spaced from the casing (i.e., elements 1.1–1.2);
• a piston 5 with rod 6 slidable in the inner cylinder (1.3);
• swivel connections 8 and 10 at top and bottom, with brackets 9 and 11 for attachment to the frame and to the main spring or axle (1.7 and, if used against claim 3, the dual-attachment structure);
• annular chambers 12 and 16 communicating with the inner cylinder and, through bleed holes 13, 17 and passages 14, 18, with the casing — the passages 14/18 being normally closed by automatically seating ball check valves 15 and 19 (this is a "valve mounted between the cylinders to retard the circulation of the liquid therethrough," element 1.4);
• orifices 20 in the wall of the inner cylinder, graduated along its length.

US 1,457,122 A — Ree, "Shock Absorber" — filed 1920-04-13, granted 1923-05-29. Text retrieved (https://patentimages.storage.googleapis.com/2c/5c/7d/2f532a596c2389/US1457122.pdf). Clean § 102(b) art. Discloses a container filled with air and a light non-compressible oil, a piston 4 with fluid passages 6 extending therethrough and enlarged at their lower ends to accommodate check valves 7, plus by-passes 8 open at all periods of operation, and a spring-supported plate 9 that closes the piston passages at the end of a long stroke. This is directly probative of the claim 2 concept of piston relief chambers that admit and control a portion of the liquid — though not of the tapered-plunger mechanism specifically.

Both are more on point than most of the page's list, and both are § 102(b)/§ 102(e) available. Their absence from the "Similar Documents" list is a limitation of Google's similarity ranking, not of the prior art.

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5. The obviousness combinations

Combination A — Claim 1: Robison '135 (or Storey '652) in view of an adjustable-throttle reference (Gruss '793 / Reynolds '923 / Harris '451)

Proposed primary: Robison & Merkell '135 (alternatively Storey '652).
Proposed secondary: a reference disclosing a valve whose damping rate is varied by an externally threaded, vehicle-attached adjusting member.

Rationale. Robison '135 supplies elements 1.1, 1.2, 1.3, and — via ball check valves 15/19 seated between the inner cylinder and the casing at the caps — arguably 1.4. What it does not clearly show is 1.5/1.6: an externally threaded element passing through the wall/end of the outer casing, carrying the valve, and serving simultaneously as the vehicle attachment point. That is the only structural idea distinguishing claim 1, and it is a pure arrangement-of-parts feature with no new function: making a valve load-adjustable by threading it through a housing end is the archetypal "known element performing its known function" modification.

Motivation to combine (KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007)). A POSITA in 1925 confronting the known problem that a fixed damping orifice cannot accommodate varying vehicle loads had a finite number of identified, predictable solutions: enlarge/shrink the orifice, add a spring-loaded blow-off valve, or make the valve seat adjustable by a screw. All three were in the art of record by 1923. The spec itself confirms the motivation, describing the screw 16 as being adjusted "to accommodate the load acting on the shock absorber" and "to regulate the flow of liquid by the valve 26 … to suit the load." That is the artisan's own statement of the problem the prior art already addressed. Under KSR, where a technique is known and the improvement is a predictable use of prior-art elements according to their established functions, the combination is obvious. Confidence: moderate-to-high that claim 1 would be held obvious, contingent on verifying that at least one available reference discloses the threaded-through-the-casing-end adjusting element. If Gruss '793 or Harris '451 does, the rejection becomes strong. If none does, claim 1 may survive on the "element threaded through one end of the exterior cylinder" limitation — narrow but real.

Anticipation note. If any single reference (Gruss '793 and Storey '652 are the candidates) discloses a twin-cylinder hydraulic absorber with an adjustable valve threaded through the outer casing end and a vehicle attachment on that element, claim 1 is anticipated under § 102, not merely obvious. Verify first.

Combination B — Claim 2: Ree '122 (or Robison '135) in view of a piston-relief/plunger reference

Proposed primary: Ree '122 (piston passages 6 with check valves 7, by-passes 8, spring plate 9) or Robison '135.
Proposed secondary: the reference(s) among Reynolds '923 / Gruss '793 / '524 / Harris '451 that discloses plungers or tapered pins on a lost-motion carrier on the piston rod controlling flow through piston ports.

Rationale. Claim 2 is the least likely to fall on the art I verified. Ree '122 gets you relief chambers with check valves and by-passes in the piston (a substantial part of element 2.2), but the tapered plungers 52 on a member 48 having limited movement on the stem is a specific structure — a lost-motion, tapered-needle metering arrangement — for which I found no verified disclosure. If any of Reynolds '923, Gruss '793, '524, or Harris '451 discloses tapered needles on a lost-motion sleeve for piston-port metering, claim 2 falls; if not, claim 2 likely survives § 103 on this record. Confidence: low-to-moderate, and driven entirely by references I could not read. I will not manufacture a disclosure that I have not seen.

Even if claim 2 survives, note the design-around problem: the closed "consisting of" transition and the very specific plunger geometry make claim 2 narrow, but correspondingly hard to invalidate and easy to avoid.

Combination C — Claim 3: Combination A extended with a dual-attachment reference

Claim 3 adds only (i) the piston stem passing through one end of the outer cylinder via a stuffing box, and (ii) a vehicle-connecting means at the stem's outer end, alongside the same at the adjusting element's end. Robison '135 discloses exactly this architecture: rod 6 through stuffing box 7 in the upper cap 2 with swivel connection 8 above it, and a second swivel connection 10 on the lower cap 3 with a saddle 11 for the axle/spring. That is the two-ended attachment claimed.

Motivation. Once claim 1's unit exists, mounting it between two relatively movable vehicle parts is not merely obvious — it is the only way such a damper can function. The spec states the balls 22 and 46 "are adjusted … according to the normal distance between the side bar A and the axle B," i.e., the dual attachment is dictated by the environment of use. Confidence: high that claim 3 is obvious over Combination A + Robison '135 (or equivalent). Indeed, claim 3 is arguably anticipated by Robison '135 alone if the adjusting-element limitation is met.

5.4 Why the pre-1925 hydraulic-damper art was a "predictable" art

The critical § 103 point is the state of the art. By January 1925, the following were all long-established, individually and in combination:

• twin-tube (inner cylinder within an outer casing, communicating passageways) hydraulic dampers;
• pistons with check-valve-controlled passages and permanent by-pass orifices;
• spring-loaded blow-off and relief valves in the piston or the head;
• variable damping by an adjustable orifice or spring preload;
• graduated/tapered orifices and metering pins; and
• ball-and-socket mounting between frame and axle.

The '311 patent's own background concedes this: the stated object is merely "a relatively simple and inexpensive device," and the stated advance is that "the flow being regulated by a valve which may be adjusted to retard the speed of circulation to accommodate the load." "Simple and inexpensive" framing is a design objective, and under KSR "the mere existence of an additional [design] objective does not render the resulting combination nonobvious." The claim set, read against that art, recites combinations of known elements performing known functions — the classic case for § 103.

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6. Secondary considerations (§ 103 objective indicia)

On the record available to me, none of the classic Graham v. John Deere secondary considerations is evidenced:

• Commercial success: No assignee is listed (the patent shows "Individual," original and current). No licensing, product-embodiment, or sales evidence appears on the page or in any search I ran.
• Long-felt need / failure of others: The crowding of the field itself (25+ similar shock-absorber patents in the 1915–1930 window, several pre-dating '311) argues widespread, successful prior activity, not failure of others.
• Praise / unexpected results: The specification claims no unexpected result. It asserts only that shocks "may be absorbed or modified to such an extent as to be hardly noticeable" — a restatement of the intended function.
• Skepticism / teaching away: None found. The art uniformly taught toward hydraulic damping with adjustable valves.

If objective indicia are to be relied on, they must be supplied by the patentee; nothing in the record supports them.

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7. Conclusion

Bottom line. The single largest § 103 hazard for this patent is not a clever multi-reference combination — it is a threshold problem the page itself conceals: 20 of the 25 "Similar Documents" are chronologically incapable of being prior art. Within the five that survive the date screen, claim 1 and claim 3 are very probably obvious (and possibly anticipated), while claim 2 is the only claim with a genuine, verifiable prospect of surviving. The reason is not the depth of the inventive concept but the narrowness of its drafting — closed "consisting of" transitions and a highly specific tapered-plunger geometry.

Recommended next steps before any rejection is finalized:

1. Retrieve the complete specifications and claims of US 1,468,652 (Storey), US 1,446,793 (Gruss), US 1,135,923 (Reynolds), US 1,519,451 (Harris), and US 1,487,524, and build an element-by-element claim chart. Nothing in this analysis should be treated as a final conclusion until that is done — I have deliberately declined to attribute disclosure content to references I could not read.
2. Confirm Hutchings' actual invention date (e.g., from any surviving assignment, interference, or drafting file). This determines whether Harris '451, '524, and the § 102(e) art are available at all; it also governs whether pre-filing § 102(a) art can be asserted.
3. Add US 1,494,135 (Robison & Merkell) and US 1,457,122 (Ree) to the search portfolio. Both are § 102(b)/(e) available and are materially closer to the claims than most of the page's list; both were surfaced only because I searched beyond the page.
4. Run a proper U.S. classification search in the 1925-era subclasses for hydraulic shock absorbers (the page classifies this patent at F16F9/00, 9/32, 9/54, 9/342 — whose modern equivalents are B60G, F16F) against the 1880–1925 window. The pre-1925 hydraulic-damper art is dense and quick to search by classification.
5. Note the drafting defects for the file record but do not conflate them with § 103: the closed transitions and the OCR-corrupted claim 1 opening ("A scribed consisting of…" for "A shock absorber of the character described consisting of…") affect claim scope and indefiniteness, not the obviousness analysis, and would be addressed under § 112.

Sources relied on: Google Patents US 1,549,311 (full text, classifications, "Similar Documents" list) — https://patents.google.com/patent/US1549311/en; FreePatentsOnline US 1,468,652 — https://www.freepatentsonline.com/1468652.html; US 1,494,135 Robison & Merkell — https://patentimages.storage.googleapis.com/ff/0c/ca/f322578c1e470a/US1494135.pdf; US 1,457,122 Ree — https://patentimages.storage.googleapis.com/2c/5c/7d/2f532a596c2389/US1457122.pdf; bibliographic data for US 1,135,923, US 1,446,793, US 1,519,451 from their Google Patents citation tables.