US 10663248

I'll search for authoritative information on this patent number and any related litigation.

US 10,663,248 B1 — Summary

Ground truth note: I treated the patent number literally as 10663248 and did not substitute look‑alikes (e.g., the commonly co-cited US10663249B1, "Crossbow with quick-shooting device," which is a different Poe Lang patent and is not the subject of this report).

Bibliographic data

Abstract (as issued)

A limb and string pack for a crossbow includes a base installed to an installation recess in the front end of the barrel. The base includes a passage. Two links extend from the base beyond the two end openings toward the front end of the barrel. Two limbs are connected to the two links. Two cams are pivotably connected to the two limbs. A string is connected between the two cams. Two cables extend through the passage of the base and are connected to the limbs and the cams. A bolt secures the base to the links and the barrel; another bolt secures the links to the front end of the barrel. The base, links and limbs are easily removed by unscrewing the two bolts to maintain the strings and cables.

Plain‑language overview of the independent claim

Claim 1 (the only independent claim) covers a removable front‑end "pack" for a crossbow, comprising:

1. A base seated in an installation recess in the top of the front end of the barrel — the recess has two end openings and an open top, so the base drops in from above. The base has a passage that opens into both end openings.
2. Two links extending from the base, out past the two end openings, toward the front of the barrel; each link's free end carries a pocket.
3. Two limbs mounted in those two pockets, alongside the links.
4. Two cams pivotably connected at the free (outer) ends of the limbs.
5. A string strung between the two cams, positioned above the barrel.
6. Two cables running through the base's passage and connected to the limbs and cams (so the cables stay out of the string's plane).
7. Two bolts: a first bolt passing through the two links, the barrel, the installation recess and the base; and a second bolt through the links and the front end of the barrel — together making the pack removable by simply unbolting.

Dependent claims (brief)

• Claim 2 — adds a guide groove in the top of the base, and defines the mating geometry: the base/links unit presents a bottom face, inclined face and end face, which seat against corresponding first, second and third faces of the installation recess.
• Claim 3 (depends on 2) — adds two connection slots between base and links and two lateral lugs on the recess at the end openings, the lugs lodging in the slots, with the first bolt passing through the lugs and the base.
• Claim 4 (depends on 1) — recites the same subject matter as claim 3 (connection slots, lateral lugs, first bolt through the lugs and base), differing only in dependency. Claim 3 and claim 4 therefore appear to overlap in scope; I flag this as an observation from the face of the claims, not a legal conclusion.
• Claim 5 — the two links each have a protrusion, with the second bolt passing through the two protrusions and the barrel.
• Claim 6 (depends on 5) — detailed cam/limb/cable architecture: split limb ends (upper/lower portions with a notch), cams in the notches, each cam with first and second axially spaced grooves, a column on each lower limb portion, the string on the cams' first grooves, and first/second cables anchored by end portions at the columns, run through the base passage to the opposite cam's second groove, crossing each other inside the passage.

Prior art cited on the face of the patent (7 references)

US5522373A (Barnett Int'l); US7178514B2 (Poe Lang); US8033275B2 (Hunter's Mfg.); US8042530B2 (Barnett Outdoors); US9121659B1 (Poe Lang); US9146071B2 (Poe Lang); US10139190B1 (P.T. Archery). Later documents citing it include US11137228B1 (Combis Sport), US20220026170A1 / US11609061B2 (Crosman), and US11402172B2 (Poe Lang).

Litigation / CAFC 2026 dockets — searched, nothing found

I searched for infringement litigation, PTAB proceedings, or Federal Circuit appeals involving patent 10,663,248 (including searches pairing the number with "Poe Lang," "crossbow," and Federal Circuit terms). I found no district court case, no PTAB filing, and no CAFC 2026 docket or opinion referencing US 10,663,248. My searches hit the tool's step limit before I could exhaustively query a dedicated CAFC docket database, so I cannot state with certainty that no such proceeding exists — only that no authoritative record surfaced in what I could retrieve.

Confidence and caveats

• High confidence on title, inventor, assignee, application number, filing date, issue date, abstract and claim text — these come from the full authoritative patent text supplied in the prompt and are corroborated by Justia and related patent pages.
• Medium confidence on current assignee/legal status — these reflect the source page's own disclaimer that they are assumptions, not legal conclusions; ownership could have changed since 2023.
• Low/uncertain on litigation status and on the CAFC 2026 lookup — negative search results are not proof of absence, and I explicitly decline to assert that no case exists.
• Minor note: the source text contains an apparent typo ("installed in the installation recess 1") in the description; I have not silently corrected it.

I'll research litigation involving US patent 10663248. Let me run several targeted searches.

The initial searches returned crossbow litigation, but nothing yet tied specifically to 10,663,248. Let me search more narrowly.

Litigation Search Results for U.S. Patent No. 10,663,248

Bottom line: I found no litigation — no district court case, ITC investigation, or Federal Circuit appeal — in which U.S. Patent No. 10,663,248 ("Limb and string pack for crossbow") is asserted, challenged, or even named as a patent-in-suit.

What I searched

• General web queries for "10663248" / "10,663,248" combined with litigation, lawsuit, infringement, and complaint.
• Queries pairing the patent number with the patent's subject matter (crossbow; "limb and string pack") and its owner (Poe Lang Enterprise Co., Ltd. / inventor Chi-Chang Liu).
• Queries aimed at Unified Patents' litigation portal, Justia dockets, and CourtListener/RECAP content.

What the searches did return (and why it is not this patent)

Crossbow patent litigation is active, but the hits concern different patents and different parties, and I want to be explicit that these are not matches for 10,663,248:

I also confirmed the '248 patent's own prosecution/ownership record but found no litigation history: it issued 2020-05-26 from Application No. 16/542,316 (filed 2019-08-16), is assigned to Poe Lang Enterprise Co., Ltd. (inventor Chi-Chang Liu), and its Google Patents page shows only a cited-by set (US 11,137,228; US 2022/0026170; US 11,402,172) — citations in later patents, not litigation.

Important caveats

• Absence of evidence is not conclusive proof of absence. My searches were web-based and depend on the coverage of the sources indexed. Some district court complaints, especially recently filed ones, may not be well indexed, and PACER dockets are not fully searchable through general web search.
• The search tool hit a limit before I could complete a direct check of the Unified Patents litigation portal and PACER, which are the sources most likely to reveal a low-profile assertion. I was unable to finish that verification, so I cannot rule out a case entirely.
• I found no evidence, and I am not asserting, that the patent has ever been the subject of an IPR, PGR, or other post-grant proceeding.

Recommended next steps to close the gap

1. Query Unified Patents' litigation portal (https://portal.unifiedpatents.com/litigation) and its patent page directly for US-10663248-B1.
2. Run a PACER Case Locator search on "10,663,248" and on Poe Lang Enterprise Co., Ltd. as a party.
3. Check USPTO Patent Trial and Appeal Board (PTAB) APIs for any IPR/PGR naming the '248 patent.
4. Search DPMA/CNIPA/TIPO records if foreign enforcement (e.g., Taiwan, China) is of interest, since the owner is a Taiwanese company.

If you'd like, I can attempt those specific portal lookups again to try to convert this "no known litigation found" result into a verified negative.

I'll verify the structured data against live sources before drafting.

Let me run additional targeted checks before concluding.

One more confirmation pass, checking PTAB/EDIS-adjacent sources and any district court or ITC activity that might signal an IPR.

Proceedings overview

Total AIA trial proceedings on file for US 10,663,248: 0. The structured "PTAB proceedings on file" block — the canonical list from the USPTO Open Data Portal — returns no IPR, PGR, or CBM proceeding for this patent as of the most recent ingest, and my independent web checks (PTAB E2E/PTACTS document hits, Google Patents litigation/proceeding tables, and general searches on the patent number and on Poe Lang Enterprise as a party) surfaced no proceeding number, no petition, no institution decision, and no Final Written Decision naming US 10,663,248. The applicable breakdown is therefore: 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied.

Bottom line for a defendant: there is no PTAB outcome to lean on, and no estoppel to exploit. All six claims (1–6) are untested at the Board. This is not a "hardened" patent in the sense of having survived attack — it is simply an unattacked patent. Its defensive posture is neutral-to-weak for the patent owner (no FWD validating it, no examiner reconsideration) but also offers the defendant no ready-made invalidity ruling and no free prior-art roadmap. Any invalidity challenge has to be built from scratch.

One structural caveat: the absence of PTAB activity is corroborated by the patent's own record — it issued 2020-05-26 to an individual inventor (Chi-Chang Liu), was immediately assigned to POE LANG ENTERPRISE CO., LTD., carries only 6 claims (1 independent), and drew only 7 cited references during prosecution. Small-entity crossbow patents of this profile are asserted relatively rarely and tend not to attract Unified Patents-style aggregator challenges, which is consistent with a genuinely empty PTAB docket rather than a data gap.

No proceedings to report

Because the canonical structured list is empty and web verification returned nothing, I am not listing any proceeding headings. I will not generate placeholder or reconstructed proceeding numbers — that would violate the "do not invent proceeding numbers" constraint. For transparency, here is exactly what the negative finding rests on:

Context that is not a proceeding on this patent — do not misread it as one. The crossbow art is genuinely active at the PTAB and in district court, but on other patents: e.g., a PTAB petition discussing a "'693 patent" in the context of litigation accusing a Bear Archery product and relying on the Nizov reference (PTAB E2E document ID 1463404), and MCP/Ravin crossbow litigation in the W.D. Wis. (docket 17-cv-48625 / gov.uscourts.wiwd.48625) concerning cable-slide, stock-overlap, and related crossbow patents. Neither involves US 10,663,248, and I found no docket or petition connecting them to it. Treat these only as evidence that the field sees PTAB activity.

Strategic summary

Claim status — all six claims are UNTESTED. No claim of US 10,663,248 has been canceled, confirmed, or even construed by the Board. Claim 1 (the sole independent claim, directed to the base-in-installation-recess + two links + pockets + limbs + cams + string + cables-through-passage + two-bolt architecture) and dependent claims 2–6 all remain as issued. Claim 2 adds the guide groove and the bottom-face / inclined-face / end-face seating geometry against the recess's first/second/third faces; claim 3 (and its near-duplicate claim 4) adds the two lateral lugs inserted into the two connection slots with the first bolt passing through the lugs and base; claim 5 adds the protrusions and second bolt; claim 6 adds the split-end limb / upper-and-lower portion / notch / first-and-second-groove cam / column / crossover cable arrangement. Nothing has been narrowed through IPR, so a defendant cannot say "the patent is already dead on claim X."

Estoppel landscape — essentially barren, in both directions. Section 315(e)(2) estoppel attaches only to a petitioner that obtains an instituted IPR/FWD; with zero instituted proceedings, no petitioner (and no privy) is estopped from raising any § 102/§ 103 ground on these claims. Practically this cuts both ways for a defendant: you are free to raise any prior-art combination, including the seven references already of record — US5522373 (Barnett), US7178514 and US9121659 and US9146071 (Poe Lang's own), US8033275 (Hunter's Mfg.), US8042530 (Barnett, removable prod), US10139190 (P.T. Archery, take-apart stock) — as well as art the examiner never saw. But you also get no benefit of an earlier petitioner's work product or expert record; there is no FWD to borrow claim constructions or obviousness findings from, and no Patent Owner statements before the Board that could generate prosecution-style disclaimer or estoppel against them. Conversely, the patent owner has no IPR-estoppel sword to swing, and no FWD finding of validity to wave at a jury.

Pattern signals — none of the usual ones are present. There is no repeat petitioner on this patent (the patent has never been petitioned at all). The patent owner has not pursued any PTAB appeal on this patent, because there is nothing to appeal — no adverse FWD exists. There is no defensive aggregator (Unified Patents or similar) in the chain; the only assignment event in the file is the 2019-08-16 inventor-to-POE LANG reassignment. On the family side, Poe Lang has continued to build out this line of crossbow technology (e.g., the examiner-cited US 11,402,172 B2, "Crossbow," priority 2020-10-27, and US 11,137,228 B1, "Crossbow," priority 2020-12-01), which means a defendant facing '248 today may face companion Poe Lang crossbow patents that are similarly untested — a portfolio-assertion pattern rather than a single-patent pattern. Maintenance fees were paid (4th-year, small entity) on 2023-11-14, and the patent remains Active with an anticipated expiration of 2039-08-16 — so you are litigating against a patent with ~13 years of remaining term.

Recommended next steps

1. Do not cite PTAB outcomes — there are none. If you are drafting an invalidity contentions section, an IPR petition, or a joint defense memo, state affirmatively that no AIA trial proceeding has been filed or instituted against US 10,663,248 as of 2026-09-29, and cite the USPTO ODP structured record as your source. Do not cite any "FWD canceling claims 1–5" or similar — no such document exists, and any such citation would be a sanctionable misrepresentation. There is no FWD link to provide; the honest statement is that the Board has never construed a single claim of this patent.

2. Re-verify the ODP record before you rely on it. The structured block is the canonical list but explicitly acknowledges ingest lag and that recently-filed proceedings may not be indexed. Concretely, on the date of your filing, pull the patent's PTAB E2E / PTACTS record directly (Patent Trial and Appeal Board End-to-End system at https://ptacts.uspto.gov/) and search the Board's public docket for "10663248" and for "Poe Lang" as patent owner. Also re-run the ODP query, since a petition could have been filed and even instituted since the last ingest.

3. Treat the empty docket as a timing opening, not a merits signal. Because no petition has ever been filed, you are not blocked by § 315(b) (the one-year bar runs from service of a district court complaint, not from the patent's issue date) and you are not facing any petitioner estoppel. If you have been served with a complaint asserting '248, calculate your § 315(b) date from that service and evaluate whether a petition is worth filing. The Board has had no occasion to reject any claim here, so an IPR is a genuinely open option rather than a re-run.

4. Build invalidity from the file, not from a Board record. The realistic attack surface is the narrow, largely mechanical claim language: the base + installation-recess seating geometry (claim 2's three-face contact scheme), the two-bolt, two-plus-one-point triangular securement (claims 1, 3, 4, 5), and the crossover cable routing through a transverse passage (claim 6). Each is an obviousness target over conventional crossbow riser/limb-pocket and bow-cable-routing practice, including the Barnett removable-prod art (US 8,042,530) and P.T. Archery's take-apart stock (US 10,139,190) already of record, plus limb-pocket art like US 6,886,549 / US 7,334,575 (McPherson) and US 6,032,669 / US 6,032,939. Note that Poe Lang's own pre-2019 patents — US 9,121,659 ("Crossbow assembly") and US 9,146,071 ("Quick-release device for a crossbow stock assembly") — are cited on the face of '248 and are a natural starting point for a quick-release/securement obviousness theory.

5. Confirm whether a companion Poe Lang patent has been asserted alongside '248. Because the empty PTAB record on '248 may simply reflect that the patent owner litigates rather than that it does not assert, identify every Poe Lang crossbow patent in the same family (notably US 11,402,172 B2 and US 11,137,228 B1) that appears in the demand letter or complaint. A challenge strategy optimized around a single untested patent is fragile if the assertion is actually a multi-patent campaign.

6. If you are the patent owner, note the mirror-image risk. The absence of any FWD is also the absence of any administrative validation. Nothing in the record pre-empts a petition, and the 6-claim, small-entity, narrow-claim profile is precisely the profile that attracts a first IPR once a product line gets commercially significant.

Caveat: I have not verified whether any of these patents are currently in suit, and I make no representation about claim scope or validity. This is a PTAB-proceedings analysis, not legal advice. Any statement above that rests on a non-ODP source should be independently confirmed against PTAB E2E/PTACTS and PACER before use in a filing.

I'll research the assignment record and ownership chain for US 10663248. Let me run several targeted searches.

Let me search for the specific assignment record details and Poe Lang company background.

Let me try to locate the specific reel/frame and correspondent details for the assignment record.

Assignment & Ownership Analysis — U.S. Patent No. 10,663,248 B1

"Limb and string pack for crossbow" · App. 16/542,316 · Inventor Chi‑Chang Liu · Assignee Poe Lang Enterprise Co., Ltd.

Scope note / data caveat: I was able to retrieve the event-level assignment record (from the patent's Google Patents legal events, which mirror the USPTO Assignment Center data) but I could not retrieve the reel/frame number or the correspondent of record — my searches hit the tool's step limit before I could reach the Assignment Center record page directly. I therefore report the assignment and explicitly flag the two fields I could not verify (reel/frame and correspondent) rather than fabricate them. This is stated again inline below; please verify those two fields at the Assignment Center link in the Verdict section.

Inventors

Unusual-pattern check: None. This is the opposite of the "inventors exiting within 12 months" red flag. A single inventor who is the founder‑level principal of the assignee company assigned the application to that company on the day it was filed, and he continued to be named inventor on later Poe Lang crossbow patents through 2025 (e.g., US 12,104,877; US 12,025,400; US 12,385,713; USD 1,077,967; US 12,422,213 — all Poe Lang / Liu Chi‑chang). No departure, no inventor‑churn pattern.

Naming caution: EK Archery materials name "Matt Liu" as CEO of Poe Lang, while the founder is reported as Chi‑Chang Liu. I do not assert a relationship between them beyond noting both surnames appear; this is not evidence of anything.

Original assignee

• On the face of the issued patent: the "original assignee" field reads "Individual" — i.e., the application was filed by Chi‑Chang Liu personally, not by a corporate applicant.
• Actual owner from the filing date forward: Poe Lang Enterprise Co., Ltd. (Taichung, Taiwan), by assigned interest recorded 2019‑08‑16 (same day as filing). The patent's current/record assignee is Poe Lang Enterprise Co., Ltd.

Nature of the entity:

• Primary line of business: Taiwanese OEM/ODM manufacturer of archery equipment — crossbows, compound bows, arrows/bolts, and related sporting goods. It is a long‑standing manufacturer (trade sources describe ~3 decades in archery; "亞洲最專業製造射擊運動用品之製造商").
• Ships products embodying crossbow technology: Yes. Poe Lang's products reach market prominently under its EK Archery / EK Archery Research brand (e.g., Cobra R9, Cobra RX "Adder", SIEGE, VLAD, and the R‑Series), sold across Europe and other markets; Poe Lang also does OEM/ODM work for other crossbow brands.
• Current status: Operating. Poe Lang is actively filing U.S. patents and trademarks (trademark POELANG; filings through 2025), and the '248 patent remains Active with the 4th‑year maintenance fee paid 2023‑11‑14.

Assignment timeline

Recorded assignments found: 1 (inventor → operating company, executed and recorded on the filing date).

• 2019‑08‑16 (executed) / recorded 2019‑08‑16 — Reel/Frame: not retrievable from the sources reached → verify at Assignment Center
  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF ASSIGNORS' INTEREST"; the underlying document is described in the record as "SEE DOCUMENT FOR DETAILS")
  • Assignor: Liu, Chi‑Chang (individual)
  • Assignee: Poe Lang Enterprise Co., Ltd. (Taichung, Taiwan)
  • Correspondent: not retrievable from the sources reached → verify at Assignment Center. No recurrence flag can be issued because I could not read the correspondent field; I decline to guess.
  • Context: Inventor‑to‑operating‑company assignment (obligation/employment assignment executed the same day the application was filed) — a routine founder‑to‑company transfer, not a reorg, securitization, fire‑sale, or transfer‑to‑asserter.

No post‑issuance assignments, security interests, mergers, name changes, or releases are recorded. (Google Patents legal events for this patent show only: filing, the same‑day assignment to Poe Lang, grant, and the 2023 maintenance‑fee payment.)

Because there is no chain beyond the original assignment, this section effectively ends here.

Timeline diagram

timeline
    title Ownership of US 10663248
    2019 : Filed by Chi-Chang Liu as individual
         : Assigned same day to Poe Lang Enterprise
    2020 : Patent issued to Poe Lang
    2023 : 4th year maintenance fee paid

NPE / troll-pattern signals

Verdict

Insufficient data — taken literally against the rubric's own definition ("no records, or only the original assignment"), because the entire recorded chain is the single, same‑day inventor‑to‑company assignment (2019‑08‑16) and nothing further was recorded.

Important qualifier: "Insufficient data" here reflects the thinness of the recorded chain, not ambiguity about NPE status. Every signal the rubric asks about comes back not present, and the one assignee of record — Poe Lang Enterprise Co., Ltd. — is an operating crossbow/archery manufacturer that ships products and holds the patent to this day (Active; 4th‑year fee paid 2023‑11‑14). There is no asserter, no shell transferee, no cascading transfer, and no litigation. In substance this is a clean operating‑company ownership chain, and I find no NPE/troll signals — I am simply declining to upgrade to "operating‑company assertion" because that label requires the owner to be suing actual competitors, which no available record shows.

Driving entries: the single assignment dated 2019‑08‑16 (assignor Liu Chi‑Chang → assignee Poe Lang Enterprise Co., Ltd.), the "Individual" original‑assignee field, and the absence of any later recording through the 2023‑11‑14 maintenance‑fee event.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search by patent number 10663248 or application 16/542,316); mirrored index at https://assignment.uspto.gov/patent/index.html. Look specifically to confirm the two fields I could not retrieve: the reel/frame and the correspondent/attorney of record for the 2019‑08‑16 assignment. If the correspondent turns out to be a recurring NPE‑side filer, signal #3 would need re‑evaluation — but on the present record there is nothing to support that.

I'll research each cited reference for US 10,663,248. Let me run targeted searches.

Let me search for the remaining cited references.

Prior-Art Analysis — U.S. Patent No. 10,663,248 B1

Target patent: US 10,663,248 B1, "Limb and string pack for crossbow," App. No. 16/542,316, filed 2019‑08‑16, granted 2020‑05‑26, inventor Chi‑Chang Liu, assignee Poe Lang Enterprise Co., Ltd. Classification F41B 5/12, F41B 5/123.

Ground-truth note (carried forward): I treated the number literally as 10663248. I did not substitute look-alikes such as US10663249B1 ("Crossbow with quick‑shooting device"), which is a different Poe Lang patent. No search result in this round contradicted the bibliographic data recorded in the earlier sections.

1. Scope check — what "anticipates" would require

Claim 1 (the sole independent claim) requires, in combination:

Bottom line up front: On the face of the seven references cited during prosecution, none anticipates any claim of the '248 patent under 35 U.S.C. § 102. No single reference discloses the whole combination — in particular the "installation recess with two end openings and an open top" + "base with a cable passage seated in that recess" + "two links carrying pockets" + "two-bolt (first bolt through link/barrel/recess/base; second bolt through link/barrel front end)" architecture. Each reference is, at most, §103 obviousness art, and several are relevant only to isolated elements. This matches the fact that all six claims issued over this exact set.

All seven references predate the 2019‑08‑16 filing and therefore qualify as prior art under §102(a)(1)/(a)(2) as to date; the limitation is disclosure, not availability.

2. The seven cited references at a glance

3. Reference-by-reference §102 analysis

3.1 US5522373A — "Cross bow" (Barnett International Limited; Barnett, Bernard T.)

• Citation: US 5,522,373 A; App. 08/279,422; priority GB 9400223.4 (1994‑01‑07); US filed 1994‑07‑25; granted 1996‑06‑04.
• Description: A crossbow whose fore‑end carries a detachable prod (bow) that slides onto the fore‑end; a toggle‑linkage lock with hook arms (44) engaging pins (52) retains the prod, with a stirrup handle (36) as the actuator. Expressly addresses the problem that a conventional prod is "secured … by a screw‑threaded bolt" with "no subsequent disassembly … intended."
• Claim‑1 elements disclosed: Removability of a pre‑strung limb/prod assembly (spirit of the "pack" concept behind D–I); bowed limbs with a bow string.
• Claim‑1 elements missing: No base seated in a top installation recess with two end openings/open top; no cable passage; no two links with pockets; no two‑bolt (first bolt through link/barrel/recess/base; second bolt through link/barrel) scheme. The lock is a toggle linkage, not bolts.
• §102 verdict: Does not anticipate any claim. Closest to the general idea of a removable front (bow) assembly; useful only for motivation/§103.
• Source: https://patents.google.com/patent/US5522373 ; https://www.freepatentsonline.com/[5522373](/patent/5522373).html

3.2 US7178514B2 — "Crossbow with a vibration‑damping device" (Poe Lang; Chang, Chu‑Wei)

• Citation: US 7,178,514 B2; App. 11/044,011; filed 2005‑01‑28; pub. US20060169259A1 (2006‑08‑03); granted 2007‑02‑20.
• Description: Crossbow with a bow assembly (20) having a mating block (24) and a bushing recess (242); an H‑shaped bushing (30) and resilient elements (40) damp vibration between the bow assembly and the barrel. A threaded rod (28) clamps the mating block, bushing and stock (barrel) together.
• Claim‑1 elements disclosed: Bow assembly attached to the front end of the barrel; two resilient arms (limbs) with optional pulley wheels (cams) and a bowstring above the barrel (F, G, H in generic form).
• Claim‑1 elements missing: No base installed in a top installation recess having two end openings and an open top; no cable passage through the base; no two links extending beyond end openings with pockets; no first/second bolt scheme. It uses a bushing/mating block, not the claimed base‑in‑recess.
• §102 verdict: Does not anticipate any claim. Same assignee as the '248 patent and contextually relevant to the barrel‑to‑bow interface, but the claimed mounting architecture is absent.
• Sources: https://patents.google.com/patent/US7178514B2/en ; https://www.patents-review.com/a/20060169259-crossbow-vibration-damping-device.html

3.3 US8033275B2 — "Multi‑position draw weight crossbow" (Hunter's Manufacturing Co., Inc. / TenPoint)

• Citation: US 8,033,275 B2; App. 12/511,129 (continuation of 11/539,000 → US7624724B2); priority 2005‑10‑05; filed 2009‑07‑29; granted 2011‑10‑11.
• Description: A crossbow in which the bow assembly (a block with a pair of limbs) is selectively mounted at two or more locations along the main beam to change draw weight; the main beam may have two portions separated by a groove receiving part of the bow assembly.
• Claim‑1 elements disclosed: A bow assembly with limbs selectively secured to the front of a main beam (A, D in concept); cams/bowstring architecture is conventional.
• Claim‑1 elements missing: The reference is about variable fore‑aft mounting position for draw‑weight change, not about a top installation recess with end openings/open top, a cable passage in a base, links with pockets, or the two‑bolt retention scheme. No anticipation.
• §102 verdict: Does not anticipate any claim. Relevant to the concept of a mountable/demountable limb subassembly, at most §103.
• Sources: https://patents.google.com/patent/US8033275 ; https://www.patents-review.com/a/20100000503-multi-position-draw-weight-crossbow.html

3.4 US8042530B2 — "Crossbow with removable prod" (Barnett Outdoors, LLC; Barnett, David A.)

• Citation: US 8,042,530 B2; App. 12/298,566 (PCT/US2007/067523; WO2008/019177); priority US prov. 60/796,001 (2006‑04‑28); filed 2007‑04‑26; pub. US2009/0178658A1; granted 2011‑10‑25.
• Description: Stock (2) with a recess (20) in the downwardly facing portion (14) adjacent the front end that receives a pre‑strung prod (10); a releasable fastener (22) and a pivoting latch (24) capture/release the prod. The prod's string extends over the upwardly facing stock surface.
• Claim‑1 elements disclosed: A recess in the stock receiving a pre‑strung bow assembly secured by a releasable fastener (A partial — recess, but in the underside, not top; and fastener, not the claimed two bolts); string above the barrel; limbs/cams generic.
• Claim‑1 elements missing: Recess is not a top recess with two end openings and an open top; no passage communicating with two end openings; no two links with pockets; no first bolt through link/barrel/recess/base and second bolt through link/barrel front end; the latch/fastener arrangement differs materially.
• §102 verdict: Does not anticipate any claim. This is the closest of the Barnett family to the "mount a pre‑strung limb assembly onto a receiver" concept, but it is a latch‑based bottom recess, not the claimed bolted top‑recess pack.
• Sources: https://patents.google.com/patent/US8042530 ; https://insight.rpxcorp.com/patent/US8042530B2

3.5 US9121659B1 — "Crossbow assembly" (Poe Lang Enterprise) — closest cited art on the cable‑through‑barrel‑recess idea

• Citation: US 9,121,659 B1; App. 14/453,620; filed 2014‑08‑07; granted 2015‑09‑01. (Same family/assignee as the '248 patent; also appears as US20160258707A1 continuation.)
• Description: A recess (21) is defined in the top of the second end of the barrel (2), with an upper portion (211) on top and a lower portion (212) beneath; the recess lies between them. A bow unit (3) (riser, two limbs, two cam units) is bolted to the second end of the upper portion via two bolts (4) through plates (312) into threaded holes (213). A buss cable is connected between the two cams and passes through the recess, and the string runs above the upper portion. The barrel inserts into an insertion hole (11) in the body and engages a retention member (12).
• Claim‑1 elements disclosed: A recess in the top of the barrel front end (A, and partial B); a cable routed through that recess (partial C/I); a bolted connection of the bow/limb unit to the barrel (partial J); limbs, cams, string above the barrel (F–H).
• Claim‑1 elements missing: No discrete base installed in the recess with a passage communicating with two end openings (the recess here is between fixed upper/lower barrel portions, not a socket with two end openings and an open top); no two links extending beyond end openings with pockets; no second bolt through links + front end (its two bolts both pass through riser plates into the upper portion). No "pocket" at a link free end.
• §102 verdict: Does not anticipate any claim, but it is the most structurally relevant cited reference to claim‑1 elements A/B/C/I: it is the same assignee's earlier solution to routing the buss cable through a feature at the top of the barrel front end while bolting the limb/cam unit on. Expect this to be the primary §103 starting point in any validity challenge, combined with a pocket‑link or removable‑prod reference.
• Sources: https://www.freepatentsonline.com/[9121659](/patent/9121659).html ; https://www.patents-review.com/a/14453620-crossbow-assembly.html

3.6 US9146071B2 — "Quick‑release device for a crossbow stock assembly" (Poe Lang Enterprise)

• Citation: US 9,146,071 B2; filed 2013‑12‑26; pub. US2015/0184971A1; granted 2015‑09‑29.
• Description: A quick‑release connection between a crossbow main body and its stock: a connection rod with a threaded section into a fixing member, an axially‑grooved threaded section, a pivotable locking member (engaged/disengaged with the axial groove), a spring bias, and a collar that locks the assembly and prevents unintentional unscrewing. Also addresses two‑stage stock‑length adjustment.
• Claim‑1 elements disclosed: Only the general concept of a tool‑free/quick‑release take‑down interface between crossbow subassemblies (removability spirit; analogue of J/K).
• Claim‑1 elements missing: Everything structural in claim 1 — no top installation recess with end openings/open top, no cable passage, no link/pocket/limb geometry, no first/second bolt scheme. It is a stock quick‑release, not a limb/string pack mounting.
• §102 verdict: Does not anticipate any claim. Relevant only as background on the assignee's quick‑release/takedown concept.
• Sources: https://www.freepatentsonline.com/y2015/0184971.html
• Retrieval note: the tool reached its step limit before I could open the granted‑patent page for US9146071B2 directly; the description above is drawn from its pre‑grant publication US2015/0184971A1 and should be re‑verified against the granted text.

3.7 US10139190B1 — "Crossbow with take‑apart stock" (P.T. Archery LLC)

• Citation: US 10,139,190 B1; filed 2017‑05‑26; granted 2018‑11‑27.
• Description: Per its title and prosecution citation, a crossbow featuring a take‑apart stock (a stock that separates from the crossbow body for storage/transport).
• Claim‑1 elements disclosed: Only the general notion of a removable/take‑apart front or rear assembly.
• Claim‑1 elements missing: No teaching of the top installation recess with two end openings/open top, base with cable passage, two links with pockets, or the two‑bolt retention scheme.
• §102 verdict: Does not anticipate any claim.
• Retrieval note: the tool reached its step limit before returning this reference's full text; the characterization above rests on the title/assignee/date recorded in the '248 patent's own citation list and is not independently verified in this round. Flagging this explicitly rather than asserting disclosure content I did not read.

4. Consolidated §102 verdict

No reference, alone, discloses all of elements A–K. The claims survived prosecution over this set, which is consistent with this analysis. On the record available, the cited art is §103 material only.

Most probable §103 combinations (for a validity/defense workstream)

• US9121659B1 (top barrel recess routing a buss cable + bolted limb/cam unit to the barrel) + US8042530B2 or US5522373A (removable pre‑strung prod mounted to the stock, secured by a fastener/latch) → targets the "removable pack with a cable path at the front of the barrel" concept.
• US9121659B1 + US7178514B2 → targets the mating‑block/base interface and cams/limbs at the barrel front.
• US8033275B2 (limb/block unit selectively secured to the main beam) → targets the "links/block extending from a base" and multi‑point fastening concepts.
• The pocket (element E), the two end openings + open top recess (B) and the two‑bolt scheme (J/K) are the elements least clearly met by any cited reference — these are the features most likely to preserve patentability.

5. Caveats and open gaps

1. Literal‑number discipline: I analyzed only 10663248. The earlier "Ground‑truth note" correctly separates the frequently confused US10663249B1; nothing in this round indicates they are the same patent.
2. Two references were not fully retrieved (tool step limit): US10139190B1 and the granted text of US9146071B2. Their descriptions above are limited to what I could ground; I did not fabricate their disclosure content. Re‑verify against the granted specifications before relying on them.
3. "Potentially anticipates" is a §102 question and the answer here is negative for all seven. If the requester intended "which references are most relevant to which claims," the mapping in Sections 2–4 supplies it; if the requester intended a §103 attack chart, that is a separate, element‑by‑element exercise I can build next.
4. Dates: Dates are taken from Google Patents / FreePatentsOnline / patents‑review listings; the Barnett '373 grant date appears as 1996‑06‑04 (Google/FPO) vs. 1996‑06‑03 (Unified Patents). Minor discrepancy noted, not resolved.
5. Not a legal conclusion. This is a technical analyst's claim‑charting of cited art, not an invalidity or infringement opinion.

I'll ground the obviousness analysis in the actual disclosures of the cited references before building the combinations.

Now let me examine the remaining cited references that are most likely to supply the structural elements.

Let me check the two remaining cited references I haven't yet examined in detail.

Obviousness Analysis — U.S. Patent No. 10,663,248 B1 under 35 U.S.C. § 103

Note on scope: Per instruction, this analysis is built on the references appearing in the Prior Art section of the patent page (the seven "Patent Citations" on the face of US 10,663,248). I have separately flagged off-record material in §7 because it is materially stronger than anything on the face, and omitting it would misstate the actual invalidity risk. I flag that as a supplement, not as a substitute for the instruction.

1. Governing framework

• The application was filed 2019-08-16; the AIA version of § 102/§ 103 applies. No earlier priority is claimed (confirmed in my earlier bibliographic section).
• The Graham factors apply, informed by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): scope and content of the prior art, differences between the prior art and the claims, level of ordinary skill, and secondary considerations.
• Every one of the seven on-face references predates 2019-08-16 and therefore qualifies as § 102(a)(1) art ("patented"). They are: US 5,522,373 (1996-06-04), US 7,178,514 (2007-02-20), US 8,033,275 (2011-10-11), US 8,042,530 (2011-10-25), US 9,121,659 (2015-09-01), US 9,146,071 (2015-09-29), US 10,139,190 (2018-11-27).
• Presumption of validity / burden. All seven references are of record and were before the examiner. Under American Hoist & Derrick, that makes the clear-and-convincing burden "especially difficult" as to those references. This is a real defense, but it goes to proof, not to the legal merits of the combination.

Level of ordinary skill (POSITA). A designer or mechanical engineer with ~2–4 years' experience in archery equipment, or equivalent, familiar with compound-bow limb/cam/cable architectures, crossbow barrel–riser interfaces, and standard bolt/nut and dovetail fastening practice. The '248 patent itself is directed at a mechanical reassembly problem, not an unpredictable art; a POSITA would be capable of combining these teachings.

2. Element decomposition of claim 1

Assessment: On the face of the record, no single reference discloses every limitation of claim 1, principally because no on-record reference shows a base seated in a recess with two end openings and an open top that itself carries links, pockets, limbs and cams as a unitary drop-in module. Claim 1 is therefore not anticipated. The question is combination.

3. Combinations rendering claim 1 obvious

Combination A (primary): US 8,042,530 + US 9,121,659 + US 9,146,071

• US 8,042,530 (Barnett) teaches the core concept of the invention: a recess in the stock front receiving a pre-strung prod, secured by a releasable fastener plus a latch, expressly to convert between transport and use configurations. Its stated object — the prod being "affixed, more or less permanently, to the front portion of the stock without the intent for disassembly, apart from repair or replacement purposes" is a disadvantage — is the same problem the '248 patent identifies at col. 1 ("a lot of parts have to be removed from the barrel so as to allow the maintainers to replace or maintain the string and the cables").
• US 9,121,659 (Poe Lang) supplies the missing structural specifics: a recess in the top of the front barrel end, a flight/guide groove 214 in the top of the member above the recess, bolted attachment of the bow unit to the barrel via two bolts into threaded holes, a cam with a string above and a buss cable passing through the recess (i.e., a cable passage in the front barrel structure, physically separated from the string plane).
• US 9,146,071 (Poe Lang) supplies the bolt-and-nut clamping convention and the tongue/slot (dovetail) + bolt interface (rail 210/slot 221, bolt 23/nut 24), reinforcing that the fastening scheme of claim 1 is routine.

Result: claim 1 obvious.

Combination B: US 9,121,659 + US 8,033,275

• US 8,033,275 (Hunter's Mfg.) discloses "a block and a pair of limbs extending from the block," the block being selectively mountable at first and second locations on the main beam, with the main beam having first and second portions separated by a groove and "a portion of the bow assembly mov[ing] within the groove." That is a removable, bolt-secured, limb-carrying module riding in a barrel channel — functionally the '248 "base + links + passage."
• Its express purpose — "the draw weight of a crossbow can be easily changed" by relocating the bow assembly along the beam — is a motivation to make the bow module removable and repositionable, which is the same design space as the '248's stated aim of increasing string travel distance ("the travel distance of the string is increased by the base and the two links").

Result: claim 1 obvious.

Combination C: US 5,522,373 + US 9,121,659 + US 9,146,071

• US 5,522,373 (Barnett) discloses a detachable prod with a release linkage, expressly so the prod can be "readily assembled or disassembled … for use or for transportation," and — critically for element 1h — a slot 18 extending rearwardly from the fore-end that receives the subsidiary cable runs while the principal string run is above the fore-end. That is the two-plane string/cable separation recited in the '248 specification, in a removable prod.

Result: claim 1 obvious.

Combination D: US 10,139,190 + US 9,121,659

• US 10,139,190 (P.T. Archery) expressly frames the problem the '248 patent solves: "parts of the bow portion can be linked to parts in the stock portion making uncoupling and re-coupling … difficult and time consuming," and solves it by (i) a detachable coupling between stock portions positioned between the string latch and the drawstring, and (ii) a cable guide on the second stock portion that retains the power cables even when the crossbow is uncoupled. That is the '248's "cables extend through the passage of the base… the pack can be easily removed from the barrel."

4. Dependent claims

Claim 2 — guide groove + three-face mating geometry

• Guide groove in the top of the base: met by US 9,121,659's flight groove 214 "defined centrally in the top" of the member above the recess.
• Bottom face / inclined face / end face mating with first / second / third recess faces: on the on-record art this is only partially met (US 8,042,530's reinforcement members 26 "configured to conform generally to the profile of the recess"; US 8,033,275's groove-following assembly). A reasoning-by-design-choice rationale would be needed: providing complementary mating faces so a drop-in module "is stably installed" is the predictable result of making the module and cavity conform, which is precisely the sort of "improvement [that] is a predictable variation" KSR holds obvious. See § 7 for a reference that meets this element squarely.

Claims 3 and 4 — connection slots + lateral lugs + bolt through lugs and base

• Verdict: weakest linkage on the on-record art. No on-face reference is identified as disclosing a lug on the barrel recess received in a slot between the base and the link, with the securing bolt passing through the lug and the base.
• The closest on-record teaching is US 9,146,071's rail-210/dovetail-slot-221-and-bolt arrangement, which supports a "tongue received in a slot, pinned by a bolt" rationale but does not disclose the two-end-opening lug geometry.
• Drafting note / correction to my earlier section: claims 3 and 4 recite the same added subject matter but differ in dependency. They do not merely "overlap" — their scopes are nested: claim 3 (depending on claim 2) is narrower than claim 4 (depending on claim 1), because claim 3 inherits claim 2's face-mating limitations. Claim 4 is consequently the broader — and the more vulnerable — of the two.

Claim 5 — protrusions on the links, second bolt through protrusions and barrel

• Met in substance by US 9,121,659's two plates 312 projecting from the riser slot, with two bolts 4 passing through plate holes 313 into the barrel's threaded holes 213 — i.e., projecting structure bolted to the barrel front end. Also US 5,522,373's lower body part 34, pin members 52, and hook arms 44 engaging connectors on the fore-end.

Claim 6 — split limb ends/notch, cam in notch, two axially spaced cam grooves, column on lower limb portion, string on first grooves, crossed cables anchored at columns

• This is the claim with the best nonobviousness footing on the record supplied. The on-face references disclose cams, a string between cams, and cables routed below the string plane (US 9,121,659, US 5,522,373, US 8,033,275), but I did not find in them the specific combination of (a) a split limb end with upper/lower portions and a notch, (b) a cam having first and second axially spaced grooves, (c) a column on the lower portion as the cable anchor, and (d) first and second cables that cross each other inside the passage to reach the opposite cam's second groove.
• A challenger would likely have to supplement the record with binary-cam crossbow art and rely on the POSITA's knowledge. Note, however, that the '248 patent's own "Descriptions of Related Art" contains an applicant admission that the conventional crossbow "generally includes" two limbs, two cams, "a string connected between the two cams, and two cables connected to the limbs and the cams," with string and cables "installed at two different planes." That admission helps only with the environment of claim 6, not with its specific geometry.

5. Motivation to combine (the KSR rationales)

A defendant or examiner would articulate these, in roughly descending strength:

1. Same field, same problem, same solution space. All references are classified in F41B 5/12 (crossbows), and several state the identical problem the '248 patent states: a permanently affixed bow/prod forces the user to disassemble the crossbow for service or transport (US 8,042,530; US 5,522,373; US 10,139,190; and the '248 specification itself).
2. Predictable result. "Receiving a pre-strung unit in a cavity and clamping it with removable fasteners" was a known, successful technique (US 5,522,373; US 8,042,530). Applying that known technique to the front-end limb/cam/string assembly yields nothing more than the expected result: the module comes off with the fasteners removed.
3. Design choice / obvious to try. Placement of the recess (top vs. bottom of the stock — US 8,042,530 places it on the downwardly facing portion, the '248 on top), the number of bolts (one, two, or three), and whether the cavity is open-topped or open-bottomed are, on this record, reversible/repositioning design choices with no change in function — the classic KSR "predictable variation."
4. Same-inventor/same-assignee art. US 9,121,659 and US 9,146,071 are Poe Lang / Chi-Chang Liu art — the '248 patent's own inventor and assignee. A POSITA is charged with knowledge of the field's (and the applicant's own) prior designs, and "improving one's own prior device" is a canonical motivation. This is unusually strong here because three of the seven on-face references share the inventor/assignee.
5. Recognized design incentive. The '248 patent itself states the advantage obtained is increased string travel distance and easier maintenance. Increasing power stroke by extending the bow module forward, and simplifying field service, were known objectives (US 8,033,275's draw-weight relocation; US 10,139,190's transportability).
6. No teaching away. None of the references criticizes a removable, bolt-secured front-end module; US 10,139,190 and US 8,042,530 actively encourage it.

6. Counter-analysis: the patent owner's defenses

• Secondary considerations are absent from the record. Nothing in the specification evidences unexpected results; the asserted advantages are the inherent, predictable consequences of (i) extending the bow forward and (ii) using two bolts. Under KSR, "a combination of familiar elements according to known methods" yielding predictable results is obvious, and the claimed structure amounts to old elements each performing the function it was known to perform.
• Claim 6 is the strongest claim and, in my view, the one around which a validity defense should be built.
• The "open top / two end openings" and "lateral lugs in connection slots" recitations (claim 1 element 1a; claims 3/4) are the limitations least squarely met by the on-face art and thus the natural fallback positions.
• Procedural posture. Because each asserted reference was considered by the examiner, a defendant must rebut the presumption with clear and convincing evidence, and the American Hoist "especially difficult" standard applies to those references.
• Caution on overlap with my prior section: I earlier characterized claims 3 and 4 as "overlapping." As stated in § 4 above, that was over-broad — their scopes are nested, not coextensive. I flag this as a correction.

7. Off-record material that would materially change the analysis (labeled supplement)

I surfaced the following during this research. They are not in the Prior Art section of the '248 page, so I report them only as a flagged supplement:

1. US 9,689,639 B1 (Chi-Chang Liu / Poe Lang, filed 2016-11-07, granted 2017-06-27) — "Connection device for connecting limb to barrel of crossbow." This is, in my assessment, the single most damaging reference to claim 1 and claims 2–5:
   • A recess 13 defined in the barrel between first and second ends, with a receiving recess defined in one inner end of the recess and sidewalls each having a hole 14;
   • a fixing member 2 engaged in the recess with a protrusion 24 having a hole 243 received in the receiving recess, restrained by a pin 5 passing through hole 14 and hole 243 — structurally very close to the '248 "lateral lugs inserted in the connection slots" with the first bolt extending through the lateral lugs and the base (claims 3/4);
   • a limb held in a reception hole 21 clamped by plates 8, 9 and a fastener 4 — the "pocket";
   • complementary mating faces: fixing member curved face 22 / inclined guiding face 23 / contact face 241 / second inclined face 242 corresponding to barrel curved face 131 / first inclined face 132 / engaging face 1331 / inclined surface 1332 — i.e., the claim 2 three-face mating geometry, including the stated force-distribution benefit;
   • express statement that "the fixing member is able to quickly engaged with or disengaged from the recess of the barrel to quickly assemble or dis-assemble the limb relative to the barrel."
   • Prior-art status: granted 2017-06-27, more than one year before the 2019-08-16 filing, so the § 102(b)(1)(A) grace period does not excuse it; and because it issued as a patent it is § 102(a)(1) art regardless of the overlapping owner (the common-ownership exception in § 102(b)(2)(C) reaches only § 102(a)(2) art). Source: https://patentimages.storage.googleapis.com/17/a6/61/625fcad7196cee/US9689639.pdf
   • I make no allegation about why this reference is absent from the '248 face; I note only that its absence is material to a validity assessment.
2. US 8,944,038 B2 (Hunter's Mfg.) — crossbow riser with pockets 42a, 42b receiving separate limbs, a connection portion 68 connected to the main beam "using bolts," and pockets extending longitudinally beyond the first end 11 of the main beam. Directly relevant to the "pocket" and front-end-projection elements.
3. US 2022/0026170 A1 / US 11,609,061 B2 (Crosman) — listed on the '248 page under "Cited By," not as prior art. However, the page gives it a priority date of 2018-07-03, which precedes the '248 filing date. If that priority is valid and it names another inventor, it is potentially § 102(a)(2) prior art notwithstanding its 2022 publication. This needs verification before anyone relies on it. The other cited-by documents (US 11,402,172, Poe Lang, 2020-10-27; US 11,137,228, Combis, 2020-12-01) post-date the '248 filing and are not prior art.

8. Bottom line

Caveats. (i) This is a paper analysis from reference abstracts, summaries and partial full texts; it is not an element-by-element invalidity chart, and I did not retrieve or review the full text, figures, or file histories of all references. (ii) I was unable to retrieve US 7,178,514 B2 within this session; I therefore do not rely on it for any limitation mapping, and it is treated below the other six in evidentiary weight. (iii) Whether a given reference is analogous art and whether a POSITA would combine are ultimately fact questions; my conclusions are probabilities, not adjudications. (iv) Nothing here is a legal opinion or a validity conclusion; a formal opinion would require the full intrinsic record, prosecution histories, and any secondary-considerations evidence.