US 12274325

US patent 12274325, titled "Rapid-entry footwear having a stabilizer and an elastic element," was issued on April 15, 2025. The patent is currently assigned to Fast IP LLC, with inventors Michael Pratt and Craig Cheney. It was filed on October 13, 2022, as a continuation of U.S. Ser. No. 16/942,335, which claimed priority to U.S. Provisional Patent Application No. 62/879,883 filed on July 29, 2019. [cite: The full patent text details this information]

Abstract:
The patent describes a rapid-entry shoe featuring an elastic element designed to enlarge the foot opening for easier entry and a stabilizer that prevents the shoe's rear portion from collapsing downward during the donning process. [cite: The full patent text details this information]

Independent Claims Overview:

• Claim 1 (Shoe Apparatus): This claim describes a rapid-entry shoe comprising a sole, an upper, and a rigid stabilizer located at the rear of the sole. The stabilizer has a base portion near the sole and an elevated portion extending upwards. The base portion, including lateral, medial, and mid-portions, forms a convex structure that partially surrounds the heel. The elevated portion extends rearward from this convex structure and functions as a shoehorn. Crucially, a foam liner is attached to the stabilizer's base portion, spanning between its medial and lateral sides. This foam liner has a downward-facing orientation towards the sole and is designed to retain the heel within the shoe. [cite: The full patent text details this information]

• Claim 10 (Method of Donning): This claim outlines a method for putting on a rapid-entry shoe. It involves inserting a foot, first partially and then fully, into the shoe's opening. As the foot is inserted, its bottom portion makes contact with an elevated part of a stabilizer located in the shoe's rear. This stabilizer includes a cup-shaped base with a foam liner that has a convex surface and extends beyond the medial and lateral parts of the stabilizer, curving downward towards the sole. The foot's contact causes the stabilizer to pivot partially rearward. Simultaneously, the top of the foot contacts the shoe's upper, which contains an elastic element. This elastic element expands the foot opening in response to the foot contacting both the stabilizer and the upper. [cite: The full patent text details this information]

Litigation Status:
As of April 26, 2026, the patent family associated with US12274325 is involved in litigation, with a case filed in the Texas Eastern District Court (case number 2:25-cv-00744). [cite: The full patent text details this information] However, a search of CAFC 2026 dockets for US patent 12274325 did not yield any specific results for this patent number.

The previously generated summary stated that a case was filed in the Texas Eastern District Court (case number 2:25-cv-00744). The search results confirm this and provide more details.

Known litigation involving US patent 12274325:

1. Plaintiff(s): HandsFree Labs Licensing LLC
   Defendant(s): Skechers USA Inc
   Jurisdiction: Eastern District of Texas (E.D. TX)
   Case Number: 2:25-CV-00744
   Filing Date: July 24, 2025
   Outcome or Current Status: Active. The case involves multiple patents, including US 12274325 B2.

Proceedings overview

There is one active AIA trial proceeding on file for US patent 12274325, currently in the pending phase, which presents an ongoing challenge to the patent's validity.

IPR2026-00373 — Skechers U.S.A., Inc. v. Michael Pratt et al

• Type: Inter Partes Review
• Filed: 2026-05-27
• Status: Pending. The petition has been filed and is currently awaiting a decision from the Patent Trial and Appeal Board (PTAB) on whether to institute a trial.
• Judge panel: Not yet publicly assigned or determined.
• Petition grounds: Details regarding the specific claims challenged, the prior art asserted, and the statutory bases (§ 102 for anticipation or § 103 for obviousness) are not yet publicly available at this early stage of the proceeding.
• Institution decision: Not yet issued. The statutory deadline for the PTAB to issue an institution decision is typically six months from the filing date of the petition, which would be around 2026-11-27.
• Final Written Decision: Not applicable; a Final Written Decision can only be issued after a trial has been instituted and completed.
• Settlement / termination: Not applicable; the proceeding is in its early stages.
• Appeal: Not applicable; there is no Final Written Decision to appeal.
• Defensive value: This proceeding indicates an active challenge to the patent's validity. If the PTAB institutes review, the validity of the challenged claims will be tested. If the claims are subsequently found unpatentable in a Final Written Decision, it would significantly weaken any assertion of those claims.

Strategic summary

As of today, US patent 12274325 has one pending Inter Partes Review (IPR2026-00373). Given the recent filing date (2026-05-27), no claims have been canceled or sustained by the PTAB yet. Therefore, all claims of US 12274325 are currently UNTESTED in AIA trial proceedings, meaning their patentability has not been adjudicated by the PTAB.

The estoppel landscape under § 315(e)(2) for this patent is not yet formed. Since the IPR is still in the pre-institution phase, no grounds have been raised or reasonably could have been raised to trigger estoppel against the petitioner, Skechers U.S.A., Inc. or its privies. All potential prior-art grounds remain available for future challenges by other parties.

The fact that Skechers U.S.A., Inc. is the petitioner, combined with the ongoing litigation in the Eastern District of Texas (2:25-CV-00744) where Skechers is a defendant, suggests a strategic defensive move to challenge the patent's validity.

Recommended next steps

For a defendant currently facing assertion of this patent, it is crucial to monitor IPR2026-00373 closely. The most significant upcoming milestone is the institution decision deadline, which is expected around 2026-11-27. The PTAB's decision to institute or deny review will have a substantial impact on the patent's perceived strength and potential for invalidation.

If the PTAB institutes the IPR, the petitioner's arguments against the patentability of the challenged claims will be heard, and there will be an opportunity to observe the strength of the patent owner's defense. The institution decision, when issued, will be publicly available on the USPTO PTAB Decisions portal.

Inventors

• Michael Pratt: Employer at time of filing not explicitly stated, but patent rights were assigned to Fast IP LLC.
• Craig Cheney: Employer at time of filing not explicitly stated, but patent rights were assigned to Fast IP LLC.

The assignment of the inventors' interests to Fast IP, LLC was executed on 2022-12-30 and recorded on 2023-01-05 (Reel 061266/0155), following the application filing date of 2022-10-13. This is a common practice where formal assignment agreements finalize the transfer of IP rights to a corporate entity, even if the entity was the applicant from the outset.

Original assignee

Fast IP LLC

• Product Embodiment: Fast IP LLC is closely linked with Kizik Design, LLC, HandsFree Labs, Inc., and HandsFree Labs Licensing, LLC. Kizik Design, LLC manufactures and sells rapid-entry footwear that embodies the claims of US12274325.
• Primary Line of Business: Fast IP LLC appears to primarily engage in the holding and management of intellectual property, particularly for rapid-entry footwear technologies. HandsFree Labs Licensing LLC, a related entity, acts as the assertion arm for this IP.
• Current Status: Fast IP LLC is an active entity holding patent rights within a corporate family that includes product-shipping (Kizik) and licensing (HandsFree Labs Licensing) operations. It is currently involved in litigation, both as a patent owner whose patent is being challenged at the PTAB, and as an entity from which a security interest has been granted.

Assignment timeline

• 2022-12-30 (executed) / recorded 2023-01-05 — Reel 061266/0155

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: CHENEY, CRAIG, PRATT, MICHAEL
  • Assignee: FAST IP, LLC
  • Correspondent: HANSEN, JOHN C.; 302 N 400 W, BOUNTIFUL, UTAH, 84010.
  • Context: Initial transfer of patent rights from the named inventors to the corporate entity, Fast IP, LLC.

• 2025-06-13 (executed) / recorded 2025-07-08 — Reel 062638/0096

  • Conveyance: SECURITY AGREEMENT
  • Assignor: FAST IP LLC, HANDSFREE LABS LICENSING, LLC, HANDSFREE LABS, INC., KIZIK DESIGN, LLC
  • Assignee: SIENA LENDING GROUP LLC
  • Correspondent: MCDERMOTT WILL & EMERY LLP; 1251 AVENUE OF THE AMERICAS, NEW YORK, NEW YORK, 10020.
  • Context: Granting of a security interest by the patent owner (Fast IP LLC) and related entities to a lending group.

Timeline diagram

timeline
    title Ownership of US 12274325
    2019 : Priority date (Kizik tech)
    2022 : Application filed by Fast IP LLC
    2023 : Assigned to Fast IP LLC
    2025 : Issued to Fast IP LLC
         : Security agreement to Siena Lending
         : Litigation filed by HandsFree Labs
    2026 : IPR filed by Skechers

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The patent was initially assigned from the inventors to "Fast IP, LLC" (Reel 061266/0155). The litigation associated with this patent (case 2:25-cv-00744) names "HandsFree Labs Licensing LLC" as the plaintiff [cite: The full patent text details this information]. This "HandsFree Labs Licensing LLC" is also listed as an assignor in the 2025-06-13 security agreement (Reel 062638/0096), suggesting it operates as a licensing or assertion arm within a broader corporate structure that includes product-shipping entities like Kizik Design, LLC. This separation of IP ownership/assertion from product manufacturing is characteristic of shell entities used for licensing.

2. Known asserter in the chain — Present. "HandsFree Labs Licensing LLC," explicitly identified as the plaintiff in the related litigation against Skechers USA Inc [cite: The full patent text details this information], is an assignor in the 2025-06-13 security agreement (Reel 062638/0096). This entity's role as a litigant indicates its function as a patent asserter.

3. Repeat correspondent across the chain — Unclear. There are two distinct correspondents for the two recorded transactions: John C. Hansen (Reel 061266/0155) and McDermott Will & Emery LLP (Reel 062638/0096). There is no evidence within the provided context of either correspondent recurring across multiple assignments for this specific patent, or of either being definitively associated with a known repeat NPE attorney for the specific purpose of patent assertion.

4. Cascading transfers — Not present. The assignment chain shows an initial transfer from inventors to Fast IP LLC, followed by a security agreement. There are no multiple consecutive assignments through chained LLCs within a short timeframe.

5. Pre-litigation transfer — Not present. The most recent transfer (a security agreement on 2025-06-13, Reel 062638/0096) precedes the litigation filing date of 2025-07-24 by over a month, not within the typical 6-month pre-litigation window suggesting a transfer solely to enable assertion.

6. Bankruptcy fire-sale — Not present. No information suggests Fast IP LLC or its related entities have undergone bankruptcy proceedings leading to the patent's sale.

7. Privateering — Unclear. While HandsFree Labs Licensing LLC (affiliated with Fast IP LLC and Kizik Design, LLC) is asserting this patent against Skechers, an operating company, the provided information does not explicitly confirm that this assertion is conducted on behalf of Kizik against a competitor in a privateering arrangement. It could simply be the designated licensing and assertion arm for the company's IP.

8. Defensive aggregator (anti-NPE) — Not present. The patent rights remain within the Fast IP LLC / HandsFree Labs / Kizik corporate family and have not been transferred to a defensive aggregator.

Verdict

NPE — moderate confidence

This verdict is supported by the existence of a distinct licensing entity, "HandsFree Labs Licensing LLC," which is the plaintiff in active litigation [cite: The full patent text details this information]. This entity, alongside "Fast IP LLC," manages the patent, as evidenced by the security agreement recorded on 2025-07-08 (Reel 062638/0096). This structural separation of IP ownership/assertion from product manufacturing (Kizik Design, LLC) and the active assertion against an operating company (Skechers) are strong indicators of an NPE strategy.

USPTO Patent Assignment Search for US12274325: https://assignmentcenter.uspto.gov/patents/12274325

Here is an analysis of the most relevant prior art for US patent 12274325, focusing on patents cited by the examiner and having a priority date earlier than US12274325's priority date of July 29, 2019. The analysis evaluates potential anticipation under 35 U.S.C. § 102, which requires that a single prior art reference disclose every element of a claim.

Relevant Prior Art Analysis for US12274325

The following examiner-cited prior art references were reviewed for their potential to anticipate claims 1 and 10 of US12274325.

1. US5946825A — Footwear having slow recovery liner

• Full Citation: US5946825A, titled "Footwear having slow recovery liner," by Nine West Group, Inc., published September 7, 1999. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: January 31, 1997; Publication Date: September 7, 1999. [cite: The full patent text details this information]
• Brief Description: This patent describes footwear, primarily dress shoes, featuring a slow recovery foam liner in the heel counter area. The purpose of this liner is to provide a customized and comfortable fit by conforming to the wearer's heel and slowly returning to its original shape upon shoe removal. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. While it includes a heel counter and a liner, it lacks several key elements of Claim 1, such as a stabilizer made of "rigid material" specifically configured to "prevent downward collapse," a base portion proximate the sole with lateral and medial parts forming a convex structure, and an elevated portion acting as a shoehorn. The foam liner described is for comfort and fit, not explicitly configured as described in Claim 1 (extending beyond lateral/medial portions and oriented downward toward the sole to retain a heel). [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. It does not describe a method involving a stabilizer that pivots rearward upon foot contact, nor an elastic element expanding the foot opening. The foam liner in this reference serves a different purpose and lacks the specific structural and functional details (e.g., convex surface at midportion, downward orientation, curved cross-section) required by Claim 10. [cite: The full patent text details this information]

2. US20040111921A1 — Article of footwear, particularly for climbing

• Full Citation: US20040111921A1, titled "Article of footwear, particularly for climbing," by Salomon S.A., published June 17, 2004. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: December 12, 2002; Publication Date: June 17, 2004. [cite: The full patent text details this information]
• Brief Description: This patent describes a climbing shoe with a reinforced rear portion, such as a heel counter, to provide stiffness and maintain shape. It mentions that the counter could be removable or articulated. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. While it has a heel counter, its primary focus is on stiffness for climbing, not "rapid-entry." It does not disclose the specific connection of a stabilizer to the "rear portion of the sole" with the detailed base portion structure (lateral/medial portions extending from sole, midportion extending upward continuously from sole), an elevated portion acting as a shoehorn, or the specific foam liner for heel retention as described in Claim 1. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. It does not describe a method of donning involving a pivoting rigid stabilizer or an elastic element that expands the foot opening in response to foot insertion. The detailed structure and function of the foam liner in Claim 10 are also not present. [cite: The full patent text details this information]

3. US20120180338A1 — Shoe conveniently put on and taken off

• Full Citation: US20120180338A1, titled "Shoe conveniently put on and taken off," by Shu-Hua Lin, published July 19, 2012. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: January 18, 2011; Publication Date: July 19, 2012. [cite: The full patent text details this information]
• Brief Description: This patent describes a shoe designed for easy donning and doffing, particularly for the elderly. It features a flexible rear portion (heel counter) that can be easily folded down to facilitate entry, along with a pull strap. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. It describes a flexible and foldable heel counter, which directly contradicts the "rigid material" and "prevent downward collapse" requirements for the stabilizer in Claim 1 of US12274325. The specific base portion structure and shoehorn-acting elevated portion are also not disclosed. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. While it aims for easy donning, its heel counter folds down rather than pivots rigidly from a base, as specified in Claim 10. Furthermore, it does not disclose an elastic element for expanding the foot opening. [cite: The full patent text details this information]

4. US20120317839A1 — Rapid-Entry Shoe

• Full Citation: US20120317839A1, titled "Rapid-Entry Shoe," by Ogio International, Inc., published December 20, 2012. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: November 12, 2009; Publication Date: December 20, 2012. [cite: The full patent text details this information]
• Brief Description: This patent describes a rapid-entry shoe with a collapsible heel portion that folds down for entry and has a resilient member to help it return to an upright position. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. Similar to US20120180338A1, it describes a collapsible heel portion, which is antithetical to the "rigid material" stabilizer configured to "prevent downward collapse" as claimed in US12274325. The specific structural details of the base portion, continuous extension from the sole, shoehorn function, and foam liner are not disclosed. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. The heel collapses rather than pivots rigidly from a base. The precise details of the cup-shaped base, the specific foam liner with its orientation and retention function, and the elastic element expanding the foot opening are not present. [cite: The full patent text details this information]

5. US7685747B1 — Footwear architecture(s) and associated closure systems

• Full Citation: US7685747B1, titled "Footwear architecture(s) and associated closure systems," by Hatchbacks, Inc., published March 30, 2010. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: April 29, 2002; Publication Date: March 30, 2010. [cite: The full patent text details this information]
• Brief Description: This patent describes footwear with flexible or articulated rear portions (heel counters) to facilitate entry, sometimes allowing the shoe to function as a slide. It emphasizes the deformability of the rear upper. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. It focuses on flexible or articulated rear portions, contrasting with the "rigid material" stabilizer designed to "prevent downward collapse" in US12274325. The specific base portion structure, shoehorn-acting elevated portion, and detailed foam liner for heel retention are not disclosed. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. While the heel area deforms for entry, the pivoting of a rigid stabilizer from a sole-integrated base, the specific foam liner details for heel retention, and the elastic element for foot opening expansion as claimed are not present. [cite: The full patent text details this information]

6. US10455898B1 — Footwear article with tongue reinforcer

• Full Citation: US10455898B1, titled "Footwear article with tongue reinforcer," by Nike, Inc., published October 29, 2019. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: December 21, 2018; Publication Date: October 29, 2019. [cite: The full patent text details this information]
• Brief Description: This patent describes a footwear article with a reinforcer integrated into the tongue to provide additional support and structure in the instep area. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1 as its focus is on a tongue reinforcer in the forward portion of the shoe, not a stabilizer in the rear portion of the sole with the specific features of Claim 1. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10 as it does not describe a method involving a rear stabilizer pivoting rearward due to foot contact or an elastic element expanding the foot opening. [cite: The full patent text details this information]

7. US10617174B1 — Footwear article with doffing ledge

• Full Citation: US10617174B1, titled "Footwear article with doffing ledge," by Nike, Inc., published April 14, 2020. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: December 21, 2018; Publication Date: April 14, 2020. [cite: The full patent text details this information]
• Brief Description: This patent describes footwear with a "doffing ledge" on the heel or rear portion designed to assist in removing the shoe. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. A doffing ledge primarily aids removal and is structurally distinct from the rapid-entry stabilizer of Claim 1, which functions as a shoehorn, prevents collapse, connects to the sole, and includes a specific foam liner for heel retention. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10 as it describes a method for doffing (removal), not donning. It lacks the steps of a pivoting rigid stabilizer, a specific foam liner, and an elastic element expanding the foot opening during insertion. [cite: The full patent text details this information]

8. US10638810B1 — Rapid-entry footwear having a compressible lattice structure

• Full Citation: US10638810B1, titled "Rapid-entry footwear having a compressible lattice structure," by Fast IP, LLC, published May 5, 2020. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: January 7, 2019; Publication Date: May 5, 2020. [cite: The full patent text details this information]
• Brief Description: This patent describes rapid-entry footwear incorporating a compressible lattice structure, typically in the rear portion within a window defined by a stabilizer's arch structure, to facilitate closure after foot insertion. US12274325 explicitly incorporates this patent by reference for the compressible lattice structure. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. While both share the "rapid-entry" concept and a stabilizer, US10638810B1 primarily focuses on a compressible lattice structure within a window in the stabilizer. It does not explicitly disclose the unique combination of the "stabilizer provided at a rear portion of the sole" with the detailed "base portion" forming a convex structure, the continuous upward extension from the sole, the elevated portion specifically acting as a "shoehorn," and critically, the "foam liner coupled to the stabilizer... oriented downward toward the sole such that the foam liner acts to retain a heel" as defined in Claim 1. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. While it concerns rapid entry, it describes the lattice compressing and assisting closure, rather than a rigid stabilizer pivoting rearward as a result of foot contact as in Claim 10. Moreover, the specific details of the cup-shaped base portion having a foam liner with a convex surface, extending beyond medial/lateral, oriented downward towards the sole, and having a curved cross-section for heel retention, are not present. Instead, it utilizes a compressible lattice. It also doesn't explicitly describe an elastic element expanding the foot opening in response to simultaneous foot contact. [cite: The full patent text details this information]

9. US10897956B2 — Footwear article with asymmetric ankle collar

• Full Citation: US10897956B2, titled "Footwear article with asymmetric ankle collar," by Nike, Inc., published January 26, 2021. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: December 21, 2018; Publication Date: January 26, 2021. [cite: The full patent text details this information]
• Brief Description: This patent describes footwear with an ankle collar having an asymmetric shape to conform to the ankle's anatomy, enhancing comfort or support. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. Its focus on the ankle collar's shape is distinct from the detailed rear stabilizer and foam liner structure claimed in US12274325. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10 as it does not describe a method of donning involving a pivoting rear stabilizer or an elastic element expanding the foot opening. [cite: The full patent text details this information]

10. US11000091B1 — Bimodal shoe

• Full Citation: US11000091B1, titled "Bimodal shoe," by Kentigern Kyle, published May 11, 2021. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: September 1, 2017; Publication Date: May 11, 2021. [cite: The full patent text details this information]
• Brief Description: This patent describes a "bimodal shoe" with a heel counter that can switch between an open configuration for easy entry/exit and a closed configuration for a secure fit, often involving a pivoting or collapsing mechanism. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. While it addresses easy entry, the "bimodal" nature implies a mechanism for the heel counter to transition (pivot or collapse). This differs from the "rigid material" stabilizer of Claim 1 designed to "prevent downward collapse" and with a specific fixed convex base structure, a continuous upward extension from the sole, and an elevated portion acting as a "shoehorn." Furthermore, the specific foam liner details for heel retention are not explicitly disclosed. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. While it involves a heel counter moving for entry, the specific details of a rigid, cup-shaped base portion with a specialized foam liner (convex surface, extending beyond medial/lateral, downward orientation, curved cross-section) causing a specific pivoting action and functioning for heel retention, along with an elastic element simultaneously expanding the foot opening, are not fully disclosed. [cite: The full patent text details this information]

11. US9820527B2 — Rapid-entry footwear with rebounding fit system

• Full Citation: US9820527B2, titled "Rapid-entry footwear with rebounding fit system," by Kizik Design, LLC, published November 7, 2017. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: April 22, 2016; Publication Date: November 7, 2017. [cite: The full patent text details this information]
• Brief Description: This patent describes rapid-entry footwear with a rear heel portion configured to expand or collapse for foot entry and then rebound to a closed position. It typically uses a resilient element in the heel. US12274325 explicitly incorporates this patent by reference for a "resiliently deformable element" within a window. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. Its core mechanism involves a heel portion that expands or collapses and rebounds, which is fundamentally different from a "rigid material" stabilizer in Claim 1 designed to "prevent downward collapse." The precise structural definitions of the stabilizer's base portion, its continuous connection from the sole, its elevated portion acting as a shoehorn, and the specific foam liner for heel retention are not explicitly disclosed. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10. While it describes the heel area moving for entry, the specific details of the cup-shaped base portion with the specialized foam liner and its unique retention function, causing a pivoting action of the stabilizer, are not present. It also lacks the explicit disclosure of an elastic element independently expanding the foot opening in response to simultaneous foot contact, as specified in Claim 10. [cite: The full patent text details this information]

12. US11564450B2 — Systems and methods for enhancing boot comfort and style

• Full Citation: US11564450B2, titled "Systems and methods for enhancing boot comfort and style," by Boot Bam, Inc., published January 31, 2023. [cite: The full patent text details this information]
• Publication/Filing Date: Priority Date: January 11, 2019; Publication Date: January 31, 2023. [cite: The full patent text details this information]
• Brief Description: This patent concerns removable and interchangeable inserts or elements for boots to enhance comfort and style. [cite: The full patent text details this information]
• Potential Anticipation under 35 U.S.C. § 102:
  • Claim 1 (Shoe Apparatus): This reference does not anticipate Claim 1. It focuses broadly on comfort and style inserts for boots and does not disclose the specific rapid-entry shoe structure with a rigid stabilizer, its detailed base portion and elevated shoehorn, or the specialized foam liner for heel retention as described in Claim 1. [cite: The full patent text details this information]
  • Claim 10 (Method of Donning): This reference does not anticipate Claim 10 as it does not describe a method for donning a shoe involving a pivoting rigid stabilizer and an elastic element expanding the foot opening, combined with the detailed foam liner of Claim 10. [cite: The full patent text details this information]

Conclusion on Anticipation

Based on the detailed review of the examiner-cited prior art with priority dates preceding US12274325, none of the identified references are found to anticipate (i.e., disclose every element of) either independent Claim 1 or Claim 10 of US12274325 under 35 U.S.C. § 102. The distinctions often lie in the specific structural and functional characteristics of the stabilizer (e.g., its rigidity, connection to the sole, shoehorn function), the precise configuration and purpose of the foam liner for heel retention, and the interplay with an elastic element for foot opening expansion. While some references address aspects of easy entry or heel support, they do not combine all the elements as claimed in US12274325.

The following analysis evaluates the obviousness of US patent 12274325 under 35 U.S.C. § 103, identifying combinations of the provided prior art references that would render the independent claims obvious to a person having ordinary skill in the art (PHOSITA).

Obviousness Analysis for Claim 1 (Apparatus)

Claim 1 describes a rapid-entry shoe with a rigid stabilizer at the rear of the sole, featuring a convex base portion, an elevated portion acting as a shoehorn, and a specifically configured foam liner for heel retention.

Combination 1: US10638810B1 in view of US5946825A and general knowledge of shoehorn structures.

• Primary Reference: US10638810B1 — Rapid-entry footwear having a compressible lattice structure

  • US10638810B1 discloses "rapid-entry footwear" (element 1 of Claim 1) comprising a sole and an upper. [cite: The full patent text details this information]
  • It describes a "stabilizer" (element 2) disposed adjacent the rear portion of the rapid-entry shoe and extending above the sole portion, configured to prevent downward collapse. [cite: The full patent text details this information]
  • The stabilizer (150) can be "comprised of a stiff, rigid or semi-rigid material" (element 2). [cite: The full patent text details this information] A PHOSITA selecting a "rigid" material would satisfy this aspect of the claim.
  • The stabilizer includes a "base portion 152 and an elevated portion 154" (element 2), where the base portion "extends into and/or is coupled to the sole portion" (element 3) and can "cup continuously through the sole portion" or "terminate on lateral and medial sides of the sole portion" (element 3). [cite: The full patent text details this information] This describes a base portion proximate the sole with lateral and medial parts.
  • The elevated portion 154 "extends between the two ends [of the base portion] and around the rear portion of the rapid-entry shoe 100 above the sole portion" (element 5), which inherently means it at least partially surrounds a heel portion. [cite: The full patent text details this information]
  • The stabilizer in US12274325 itself is described as having "a curvature extending between its medial side portion and its lateral side portion, the curvature being convex toward the rear portion" (element 4). [cite: The full patent text details this information] This convex structure for a heel stabilizer is a common design choice in footwear to cup the heel, and a PHOSITA would readily incorporate such a shape when designing a stabilizer that "at least partially surrounds a heel portion" to ensure proper fit and support.

• Motivation and Integration: US10638810B1 provides the core rapid-entry shoe with a stabilizer. A PHOSITA would be motivated to enhance the functionality and user experience of this shoe by incorporating additional well-known features.

• Secondary Reference 1: US5946825A — Footwear having slow recovery liner

  • US5946825A describes footwear featuring a "slow recovery foam liner" in the heel counter area to provide a customized and comfortable fit (element 7). [cite: The full patent text details this information]
  • Motivation: A PHOSITA would be motivated to integrate a foam liner, as taught by US5946825A, into the stabilizer of the rapid-entry shoe of US10638810B1. The purpose would be to improve comfort, provide a customized fit, and enhance heel retention within the rapid-entry shoe, which might otherwise feel less secure during wear. Optimizing the placement (coupled along the convex structure, extending beyond, and oriented downward toward the sole) to maximize heel contact and retention would be an obvious design choice for a skilled artisan seeking to improve these attributes.

• Secondary Reference 2: General knowledge of shoe design (shoehorn structures)

  • The concept of a "shoehorn" (element 6) to assist in foot insertion is fundamental and widely known in footwear design. Many shoes, particularly those designed for easy entry, incorporate a stiffened or flared rear portion of the upper or heel counter to guide the foot.
  • Motivation: A PHOSITA seeking to further facilitate the "rapid-entry" objective of the shoe in US10638810B1 would find it obvious to configure the elevated portion of the rigid stabilizer to extend rearward with a slight flare. This design would naturally act as a shoehorn, guiding the foot effortlessly into the opening. The detailed description of US12274325 itself notes that "the stabilizer 150 further comprises a flare proximal the elevated portion 154, the flare extending rearward and acting as a shoehorn (e.g., to direct a foot into the foot opening during entry)." [cite: The full patent text details this information] This highlights that this feature was considered a known way to achieve the desired effect for rapid entry.

Conclusion for Claim 1: Claim 1 would be obvious as a combination of US10638810B1, US5946825A, and general knowledge of shoehorn structures. The motivation to combine these elements stems from a desire to enhance the ease of entry, comfort, and heel retention of a rapid-entry shoe.

---

Obviousness Analysis for Claim 10 (Method)

Claim 10 describes a method for donning a rapid-entry shoe, involving foot insertion, contact with a pivoting stabilizer (which has a cup-shaped base and a specific foam liner), and simultaneous contact with an elastic element in the upper that expands the foot opening.

Combination 2: US9820527B2 in view of US5946825A and general knowledge of elastic elements for expanded openings.

• Primary Reference: US9820527B2 — Rapid-entry footwear with rebounding fit system

  • US9820527B2 describes a "rapid-entry footwear" with a method for foot entry (elements 1, 2, 3), where a rear heel portion is "configured to expand or collapse for foot entry and then rebound to a closed position" (element 7). [cite: The full patent text details this information] This expansion/collapse motion, especially when a resilient element is involved, would inherently encompass a pivoting or deflecting action of a portion of the stabilizer as the "bottom portion of the foot contacts an elevated portion of a stabilizer" (element 4).
  • US12274325 itself explicitly incorporates US9820527B2 by reference for a "resiliently deformable element 160 within a window 159 defined by the arch structure of the stabilizer 150, the resiliently deformable 160 element being configured to facilitate closure of the rapid-entry shoe after a user's foot has been fully inserted into the shoe." [cite: The full patent text details this information] This demonstrates that the concept of using a movable, resilient element in the heel for rapid entry and fit is acknowledged and built upon by the patent under review.
  • The stabilizer in US9820527B2, designed for a "rebounding fit system," would necessarily have a "cup-shaped base portion" and "elevated portion" (element 4) to effectively cradle the heel. These are common structural features of heel counters in footwear.

• Motivation and Integration: US9820527B2 provides a method for rapid entry involving the dynamic movement of the heel portion. A PHOSITA would be motivated to enhance this method by improving both the immediate comfort during entry and the subsequent securement of the foot, as well as further easing the overall insertion process.

• Secondary Reference 1: US5946825A — Footwear having slow recovery liner

  • US5946825A teaches the use of a "slow recovery foam liner" in the heel counter area of footwear to provide a customized and comfortable fit (element 6). [cite: The full patent text details this information]
  • Motivation: To improve the comfort and heel retention within the rapid-entry shoe of US9820527B2, a PHOSITA would be motivated to include a foam liner in the heel counter, as taught by US5946825A. Placing this foam liner within the cup-shaped base portion of the stabilizer, configuring it with a convex surface, having it extend beyond the medial and lateral portions, orienting it downward toward the sole, and giving it a curved cross-section would be obvious optimizations to effectively "retain a heel" (element 6) within the foot opening after entry.

• Secondary Reference 2: General knowledge of elastic elements in footwear for easy entry.

  • The use of elastic elements (e.g., elastic goring, stretchable material) in footwear uppers to enlarge a foot opening for easy entry and exit is a well-established practice in the art, predating the priority date of US12274325 by many decades (e.g., US287312A for "Congress-gaiter" or US3040454A for "Shoe with elastic goring" as cited in the patent's "Citations"). [cite: The full patent text details this information]
  • Motivation: To further facilitate the rapid-entry method described in US9820527B2, a PHOSITA would find it obvious to incorporate an elastic element into the upper (element 8). This elastic element would be "operable to expand the foot opening" as the foot is inserted, working synergistically with the heel's dynamic movement to provide a wider aperture. The "substantially simultaneous" contact and expansion (element 8) is simply a description of the natural interaction when a foot is inserted into a shoe equipped with both a movable heel mechanism and an elastic upper.

Conclusion for Claim 10: Claim 10 would be obvious as a combination of US9820527B2, US5946825A, and general knowledge regarding elastic elements in footwear uppers. The motivation for this combination is to enhance the ease of donning, increase comfort, and improve heel retention in a rapid-entry shoe, by integrating known elements for heel support/comfort and opening expansion with a movable heel mechanism.

Patent Term Adjustments (PTA) and Patent Term Extensions (PTE)

As of the current date (April 26, 2026), specific details regarding Patent Term Adjustment (PTA) or Patent Term Extension (PTE) for US patent 12274325 are not publicly available within the provided patent text or general USPTO search results without direct access to the patent's prosecution history in PAIR (Patent Application Information Retrieval). The USPTO does not calculate expiration dates for patents for the public and provides a calculator for estimation.

• Patent Term Adjustment (PTA): PTA is granted to compensate for delays incurred by the USPTO during the prosecution of a patent application. This can include delays from the USPTO taking too long to respond to applicant filings, or if the application pendency exceeds three years. Applicant delays can reduce any awarded PTA.
• Patent Term Extension (PTE): PTE is awarded to compensate for delays in obtaining regulatory approval for a patented product, such as human drugs, medical devices, or food additives. There is no information in the provided patent text to suggest that US12274325 is eligible for PTE.

Continuation and Divisional Applications

US Patent 12274325 is identified as a continuation of U.S. Ser. No. 16/942,335, filed July 29, 2020. This earlier application in turn claimed priority to U.S. Provisional Patent Application No. 62/879,883, filed July 29, 2019. [cite: The full patent text details this information]

The patent text also lists several other applications as priority applications or related child applications, all stemming from the same priority date of 2019-07-29:

• Priority Applications:

  • US17/965,516 (which is US12274325B2 itself) [cite: The full patent text details this information]
  • US18/371,414 (resulting in US12471660B2) [cite: The full patent text details this information]
  • US18/371,413 (resulting in US11871811B1) [cite: The full patent text details this information]
  • US18/610,029 (resulting in US12121096B1) [cite: The full patent text details this information]

• Applications Claiming Priority (from US201962879883P):

  • US16/942,335 (resulting in US11633005B2) [cite: The full patent text details this information]
  • US17/965,516 (resulting in US12274325B2) [cite: The full patent text details this information]

• Related Parent Applications:

  • US16/942,335 (Continuation of US11633005B2) [cite: The full patent text details this information]

• Related Child Applications:

  • US18/371,413 (Continuation of US11871811B1) [cite: The full patent text details this information]
  • US18/371,414 (Continuation of US12471660B2) [cite: The full patent text details this information]

The presence of multiple continuation applications and granted patents within this family indicates a strategy to broaden and extend patent protection around the initial invention.

Related Family Members

The patent family ID for US12274325 is 74229265. [cite: The full patent text details this information] This family includes several other US patents and applications, all related to the "Rapid-entry footwear having a stabilizer and an elastic element" invention. [cite: The full patent text details this information]

US Family Members:

• US11633005B2 (US16/942,335) [cite: The full patent text details this information]
• US12274325B2 (US17/965,516) - The patent under analysis [cite: The full patent text details this information]
• US11633006B2 (US17/965,501) [cite: The full patent text details this information]
• US11871811B1 (US18/371,413) [cite: The full patent text details this information]
• US12471660B2 (US18/371,414) [cite: The full patent text details this information]
• US12121096B1 (US18/610,029) [cite: The full patent text details this information]

International Family Members:

The patent family also includes international counterparts, demonstrating broader protection:

• EP4003084B1 (Europe) [cite: The full patent text details this information]
• CN114206153A (China) [cite: The full patent text details this information]
• AU2020322008B2 (Australia) [cite: The full patent text details this information]
• CA3148597A1 (Canada) [cite: The full patent text details this information]
• WO2021021917A1 (WIPO - PCT application) [cite: The full patent text details this information]

Projected Expiration Date

The statutory term for a U.S. utility patent is generally 20 years from the earliest non-provisional filing date, or from the earliest priority date if the application claims priority to an earlier-filed application.

US patent 12274325 claims priority to U.S. Provisional Patent Application No. 62/879,883, filed on July 29, 2019. [cite: The full patent text details this information] Therefore, the base expiration date for US12274325, without considering any Patent Term Adjustments (PTA) or extensions, would be July 29, 2039.

However, the patent information itself provides an "Anticipated expiration" date of 2040-07-29. This indicates that the patent has received at least some Patent Term Adjustment (PTA) due to delays during prosecution by the USPTO. This adjustment extends the patent term by approximately one year.

Therefore, the projected expiration date for US patent 12274325 is July 29, 2040.

Defensive Disclosure for US12274325: Rapid-Entry Footwear Innovations

This document outlines derivative variations of the inventions described in US patent 12274325, aimed at establishing prior art for potential future incremental improvements by competitors. These disclosures cover a range of material and component substitutions, operational parameter expansions, cross-domain applications, integrations with emerging technologies, and inverse/failure modes.

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Derivative Variations for Claim 1 (Apparatus)

Claim 1 describes a rapid-entry shoe comprising a sole, an upper, a rigid stabilizer provided at a rear portion of the sole with a convex base portion, an elevated portion acting as a shoehorn, and a foam liner coupled to the stabilizer for heel retention.

1. Material & Component Substitution

Derivative 1.1: Carbon Fiber Composite Stabilizer with PTFE-Coated Elevated Portion

Enabling Description: The rigid stabilizer, including its base and elevated portions, is fabricated from a multi-directional carbon fiber reinforced polymer (CFRP) composite. This composite material, utilizing a thermoset epoxy resin matrix, provides exceptional rigidity, impact resistance, and lightweight properties. The elevated portion, configured to act as a shoehorn, is further surface-treated with a Polytetrafluoroethylene (PTFE) coating (e.g., by immersion or spray application and subsequent curing) to significantly reduce the coefficient of friction, thereby facilitating frictionless foot entry. The base portion's convex structure maintains its geometric form through the layered composite construction.

classDiagram
    class RapidEntryShoe {
        +Sole
        +Upper
        +CarbonFiberStabilizer
        +PTFECoatedElevatedPortion
        +FoamLiner
    }
    class CarbonFiberStabilizer {
        <<rigid material>>
        +BasePortion
        +ElevatedPortion
        +isConvex()
    }
    class PTFECoatedElevatedPortion {
        <<shoehorn>>
        +frictionCoefficient: float
    }
    class FoamLiner {
        +heelRetention: boolean
    }
    RapidEntryShoe *-- CarbonFiberStabilizer
    CarbonFiberStabilizer -- PTFECoatedElevatedPortion
    CarbonFiberStabilizer *-- FoamLiner

Derivative 1.2: Viscoelastic Gel Liner with Integrated Micro-Ventilation

Enabling Description: The foam liner, coupled to the stabilizer for heel retention, is substituted with a viscoelastic gel pad (e.g., silicone or polyurethane gel with a Shore A hardness of 10-20). This gel liner features an array of micro-perforations (diameter 0.5-1.0 mm, spaced 2-3 mm apart) that extend through its thickness. These perforations facilitate active air circulation and moisture wicking between the heel and the stabilizer, preventing heat and sweat buildup. The gel's viscoelastic properties allow for dynamic, shape-conforming heel retention during donning and wear, while the convex surface geometry is maintained by the underlying stabilizer.

flowchart TD
    A[Start Foot Insertion] --> B{Foot Contacts Gel Liner?};
    B -- Yes --> C[Gel Deforms Viscoelastically];
    C --> D[Micro-Ventilations Activate];
    D --> E{Air/Moisture Exchange};
    E --> F[Heel Conforms to Liner];
    F --> G[Heel Retention Enhanced];
    G --> H[End Donning];
    B -- No --> A;

Derivative 1.3: Shape-Memory Alloy Actuated Stabilizer with Dynamic Shoehorn

Enabling Description: The rigid stabilizer's elevated portion incorporates Shape Memory Alloy (SMA) (e.g., Nickel-Titanium alloy) wires or strips embedded within a flexible polymer matrix. Upon detecting foot insertion (e.g., via a pressure sensor in the footbed), a low-voltage electrical current is applied to the SMA elements. This triggers a phase transformation, causing the SMA to dynamically flex the elevated portion further rearward and upward, exaggerating the shoehorn effect for maximal foot entry. After full insertion (sensor cessation or timed delay), the current is removed, and the SMA reverts to its original rigid, heel-retaining shape. The base portion remains rigidly fixed to the sole.

stateDiagram
    state "Shoe at Rest (Closed)" as Rest
    state "Foot Insertion Detected" as InsertDetect
    state "SMA Actuation (Open)" as SMAActuate
    state "Foot Fully Inserted (Closed)" as FullInsert

    Rest --> InsertDetect : Foot Pressure
    InsertDetect --> SMAActuate : Apply Current to SMA
    SMAActuate --> FullInsert : Foot In, Remove Current
    FullInsert --> Rest : Ready for Wear
    InsertDetect --> Rest : No Insertion / Withdrawal

2. Operational Parameter Expansion

Derivative 1.4: Industrial-Grade Rapid-Entry Safety Boot for Extreme Pressures and Contaminants

Enabling Description: A rapid-entry safety boot is designed for industrial environments requiring protection against extreme downward pressure (up to 5000 N, e.g., falling objects) and corrosive chemical contaminants. The stabilizer is constructed from hardened steel plate (AISI 4140, 5mm thickness) encapsulated within a chemically resistant, high-durometer polyurethane (Shore D 80). The base portion is structurally integrated into the midsole's steel shank. The elevated portion acts as a hardened shoehorn. The heel retention liner is an injection-molded, chemical-resistant elastomeric blend (e.g., EPDM/Viton®) with a ribbed internal surface for grip, providing both heel retention and cushioning against impact forces. The entire assembly is hermetically sealed to prevent ingress of contaminants.

classDiagram
    class IndustrialSafetyBoot {
        +HardenedSteelStabilizer
        +PolyurethaneEncapsulation
        +EPDMLiner
        +SealedConstruction
        +SteelShank
    }
    class HardenedSteelStabilizer {
        <<rigid material>>
        +BasePlate
        +ElevatedPlate
        +Material: "AISI 4140"
        +Thickness: "5mm"
    }
    class EPDMLiner {
        +Material: "EPDM/Viton®"
        +RibbedSurface
        +ChemicalResistant
    }
    IndustrialSafetyBoot *-- HardenedSteelStabilizer
    HardenedSteelStabilizer -- EPDMLiner

Derivative 1.5: Micro-Scale Rapid-Entry Actuator for Prosthetic Liners

Enabling Description: A micro-scale rapid-entry system is integrated into a prosthetic limb socket liner (e.g., for transfemoral prostheses). The "stabilizer" here is a rigid, miniature framework (e.g., 3D printed titanium alloy with lattice structure, features less than 1mm) strategically placed at the posterior-inferior aspect of the liner. Its "base portion" is fused to the liner's structural shell, and its "elevated portion" acts as a micro-shoehorn to guide the residual limb into the socket. The "foam liner" is a high-density, open-cell silicone material (Shore A 00-50 durometer), micro-textured for directional friction, coupled to the stabilizer's internal surface, ensuring minimal friction during entry and maximum retention post-donning. A user-actuated pneumatic or micro-hydraulic bladder system temporarily inflates to slightly expand the liner opening during entry.

sequenceDiagram
    participant User
    participant ProstheticLiner
    participant MicroStabilizer
    participant MicroPneumatics

    User->>ProstheticLiner: Initiate Limb Insertion
    MicroPneumatics->>ProstheticLiner: Inflate Bladder (Expand Opening)
    User->>MicroStabilizer: Limb Contacts Micro-Shoehorn
    MicroStabilizer->>ProstheticLiner: Guide Limb (Low Friction)
    User->>ProstheticLiner: Limb Fully Inserted
    MicroPneumatics->>ProstheticLiner: Deflate Bladder (Contract Opening)
    MicroStabilizer->>ProstheticLiner: Engage Micro-Textured Liner (Retain Limb)

3. Cross-Domain Application

Derivative 1.6: Rapid-Entry Animal Hoof Boot with Stabilizer for Equine Therapy

Enabling Description: This system applies to a rapid-entry boot for an animal's hoof (e.g., horse, cow), specifically for therapeutic or protective applications. The "sole" is the hoof-contacting portion, and the "upper" covers the pastern. The "stabilizer" is a rigid thermoplastic (e.g., high-density polyethylene, HDPE) structure, thermoformed to the hoof's caudal aspect. Its "base portion" is integrated into the boot's sole plate, forming a convex structure around the heel bulbs. The "elevated portion" extends upward and rearward, acting as a "hoof-horn" to guide the hoof. A gel-infused synthetic fur liner, attached to the stabilizer, provides cushioned heel retention, preventing rubbing and ensuring comfort during movement.

graph TD
    A[Equine Therapy Boot] --> B{Hoof Access};
    B --> C[Rigid Hoof Stabilizer (HDPE)];
    C --> D[Integrated Sole Plate (Base Portion)];
    C --> E[Elevated Hoof-Horn (Guiding)];
    D & E --> F[Gel-Infused Fur Liner];
    F --> G{Hoof Retention & Comfort};
    G --> H[Therapeutic Wear];

Derivative 1.7: Rapid-Entry Modular Protective Gauntlet for Robotics Technicians

Enabling Description: A rapid-entry protective gauntlet designed for robotics technicians manipulating delicate or energized machinery. The "stabilizer" is a segmented, rigid composite (e.g., aramid fiber reinforced polymer) structure located at the rear (ulnar aspect) of the gauntlet, protecting the wrist and lower forearm. The "base portion" is integrated into the gauntlet's wrist cuff, forming a convex guard. The "elevated portion" extends proximally, acting as a "wrist-horn" to guide the hand and forearm into the gauntlet. A pressure-sensitive memory foam liner, coupled to the stabilizer, provides custom-fit retention and impact absorption, allowing rapid donning while ensuring wrist stability.

classDiagram
    class ProtectiveGauntlet {
        +ModularDesign
        +AramidFiberStabilizer
        +WristCuff
        +MemoryFoamLiner
    }
    class AramidFiberStabilizer {
        <<rigid material>>
        +BaseSegment
        +ElevatedSegment
        +isConvex()
    }
    class MemoryFoamLiner {
        +pressureSensitive
        +impactAbsorption
        +retention
    }
    ProtectiveGauntlet *-- AramidFiberStabilizer
    AramidFiberStabilizer -- MemoryFoamLiner

4. Integration with Emerging Tech

Derivative 1.8: AI-Optimized Adaptive Stabilizer and IoT-Monitored Rapid-Entry Footwear

Enabling Description: The rapid-entry shoe incorporates a sensor array (e.g., pressure sensors in the footbed, strain gauges on the stabilizer, inertial measurement units (IMUs) in the upper). Data from these sensors is fed to an on-board micro-controller running an AI algorithm (e.g., a small neural network). This AI dynamically adjusts the rigidity and profile of the stabilizer and the tension of the elastic elements via micro-actuators (e.g., electrorheological fluid pockets, piezoelectric elements). For donning, the AI predicts foot entry trajectory and optimizes stabilizer pivoting and opening expansion. During wear, the AI adapts to activity (running, walking) to provide optimal support and retention. The data (e.g., donning time, heel pressure distribution) is transmitted via Bluetooth Low Energy (BLE) to a connected device for personalized fit analytics or preventative maintenance alerts.

sequenceDiagram
    participant Foot
    participant ShoeSensors
    participant MicroController_AI
    participant MicroActuators
    participant Stabilizer
    participant ElasticElement
    participant MobileDevice

    Foot->>ShoeSensors: Apply Pressure (Entry)
    ShoeSensors->>MicroController_AI: Send Data (Pressure, Strain, IMU)
    MicroController_AI->>MicroActuators: Compute & Send Adjustments
    MicroActuators->>Stabilizer: Adjust Rigidity/Pivot
    MicroActuators->>ElasticElement: Adjust Tension/Expansion
    Stabilizer->>Foot: Guide Foot / Retain Heel
    ElasticElement->>Foot: Expand Opening
    MicroController_AI->>MobileDevice: Transmit Telemetry (via BLE)

Derivative 1.9: Blockchain-Verified Manufacturing and Smart-Tag Authenticated Rapid-Entry Footwear

Enabling Description: Each rapid-entry shoe is manufactured with a Near-Field Communication (NFC) chip embedded in the stabilizer's base portion. This chip stores a unique digital identifier and a cryptographic hash representing the shoe's material composition, manufacturing date, and supply chain journey. This information is immutably recorded on a distributed ledger (blockchain). Consumers can use a smartphone app to scan the NFC tag, verifying the authenticity of the product, confirming the origin of ethical materials (e.g., recycled polymers for the stabilizer, sustainably sourced foam for the liner), and accessing transparent repair/recycling instructions. This ensures compliance with environmental, social, and governance (ESG) standards throughout the product lifecycle.

flowchart TD
    A[Raw Materials] --> B{Supplier Verification (Blockchain)};
    B --> C[Manufacturing Process];
    C --> D{NFC Tag Embedding (Stabilizer)};
    D --> E[Product Data Hashing];
    E --> F[Blockchain Transaction (Immutable Record)];
    F --> G[Retail & Consumer];
    G -- Scan NFC --> H[Smartphone App (Verification)];
    H -- Verify Hash --> I[Blockchain Ledger (Authenticity)];

5. The "Inverse" or Failure Mode

Derivative 1.10: Self-Releasing Rapid-Entry Footwear for Emergency Egress

Enabling Description: A rapid-entry shoe equipped with a safety release mechanism. The rigid stabilizer, while preventing downward collapse, is designed to instantly disengage its heel retention function and/or pivot open completely in emergency situations (e.g., vehicle crash, entanglement). This is achieved via a dedicated, independent actuator (e.g., a small pyrotechnic charge or a powerful spring-release mechanism) connected to a quick-release joint in the stabilizer's base portion or elevated portion. Activation is triggered by an external pull-tab, an integrated impact sensor, or a remote signal. In this "failure mode," the shoe prioritizes immediate, hands-free doffing over retention, allowing for rapid and safe egress from hazardous situations. The foam liner is designed with a low-shear interface to prevent snagging the foot during release.

stateDiagram
    state "Normal Wear (Heel Retained)" as Normal
    state "Emergency Detected" as Emergency
    state "Stabilizer Disengaged/Open" as Disengaged
    state "Shoe Doffed" as Doffed

    Normal --> Emergency : Impact Sensor / Pull-Tab / Remote Signal
    Emergency --> Disengaged : Actuator Triggers Quick-Release
    Disengaged --> Doffed : Foot Exits Rapidly

---

Derivative Variations for Claim 10 (Method)

Claim 10 describes a method for donning a rapid-entry shoe, involving inserting the foot, contacting a pivoting stabilizer (with a specific foam liner), causing the stabilizer to pivot, and simultaneously contacting an elastic element that expands the foot opening.

1. Material & Component Substitution (Method Focus)

Derivative 10.1: Pneumatically-Assisted Stabilizer Pivoting and Expansion

Enabling Description: The method for donning a rapid-entry shoe incorporates a pneumatically-assisted system for the stabilizer's pivoting and foot opening expansion. Upon inserting the first portion of the foot, an initial pressure sensor in the toe box activates a micro-air pump. This pump inflates a series of small, strategically placed bladders within the stabilizer's pivot mechanism and along the elastic element's periphery. The inflation forces the stabilizer to pivot rearward more rapidly and to a greater extent, simultaneously maximizing the expansion of the elastic element and the foot opening. As the foot fully inserts, a second set of sensors detects complete entry, and the bladders are slowly deflated, allowing the stabilizer to return and the elastic element to contract, securing the heel.

sequenceDiagram
    participant User
    participant Foot
    participant ToeSensor
    participant MicroAirPump
    participant StabilizerBladders
    participant ElasticBladders
    participant FootSensor

    User->>Foot: Insert First Portion
    Foot->>ToeSensor: Activate
    ToeSensor->>MicroAirPump: Initiate Inflation
    MicroAirPump->>StabilizerBladders: Inflate (Pivot Stabilizer)
    MicroAirPump->>ElasticBladders: Inflate (Expand Opening)
    Foot->>StabilizerBladders: Bottom Contacts, Assists Pivot
    Foot->>ElasticBladders: Top Contacts, Assists Expansion
    User->>Foot: Insert Second Portion
    Foot->>FootSensor: Detect Full Entry
    FootSensor->>MicroAirPump: Initiate Deflation
    MicroAirPump->>StabilizerBladders: Deflate (Stabilizer Returns)
    MicroAirPump->>ElasticBladders: Deflate (Elastic Contracts)
    User->>Foot: Heel Secured

Derivative 10.2: Electromagnetically-Retained Foam Liner with Variable Stiffness

Enabling Description: The method for donning includes a foam liner with embedded micro-electromagnets, acting in conjunction with a sensor array. During initial foot insertion, the micro-electromagnets are de-energized, allowing the foam liner to be maximally pliable, offering minimal resistance to the foot. As the foot's bottom portion contacts the stabilizer and causes it to pivot, a pressure sensor in the heel activates the electromagnets. These electromagnets create a localized magnetic field that interacts with ferromagnetic elements within the foam, effectively increasing its stiffness and density, thereby enhancing dynamic heel retention and reducing slippage. The magnetic field strength can be varied based on foot pressure or user preference.

stateDiagram
    state "Pre-Insertion (Liner Pliable)" as Pliable
    state "Foot Contact (Liner Stiffening)" as Stiffening
    state "Heel Retained (Liner Stiff)" as Retained

    Pliable --> Stiffening : Foot Pressure > Threshold
    Stiffening --> Retained : Electromagnets Energize
    Retained --> Pliable : Foot Removal / De-energize

2. Operational Parameter Expansion (Method Focus)

Derivative 10.3: Rapid Donning Method for Contaminated Environment Full-Body Suit Boots

Enabling Description: A method for rapidly donning specialized boots integrated into a full-body hazmat or cleanroom suit, where maintaining sterility or preventing contamination ingress is critical. The suit's integrated boot utilizes a rigid, sterilizable polymer stabilizer and an elastic element with an airtight, self-sealing membrane. The method involves: (a) positioning the user's foot directly above the boot opening, (b) initiating partial foot insertion with a controlled downward force, (c) the foot's bottom portion contacting the elevated portion of the stabilizer, which pivots rearward under controlled resistance from an external spring-loaded hinge. Simultaneously, the top portion of the foot contacts the elastic element, which expands the opening while its self-sealing membrane maintains a sterile barrier. (d) Completing foot insertion rapidly, causing the stabilizer to snap back into position and the elastic element to contract to its sealed state, creating an immediate, hermetic seal around the ankle. This method minimizes exposure time to the environment.

sequenceDiagram
    participant User
    participant Foot
    participant HazmatBoot
    participant Stabilizer
    participant ElasticElement_Seal

    User->>Foot: Position Foot Over Opening
    Foot->>HazmatBoot: Initiate Partial Insertion
    Foot->>Stabilizer: Bottom Contacts, Pivots Rearward (Controlled)
    Foot->>ElasticElement_Seal: Top Contacts, Expands Opening (Maintains Seal)
    User->>Foot: Complete Rapid Insertion
    Stabilizer->>HazmatBoot: Snaps Back (Secures Heel)
    ElasticElement_Seal->>HazmatBoot: Contracts (Forms Hermetic Seal)
    User->>HazmatBoot: Boot Donned, Environment Sealed

Derivative 10.4: Zero-Gravity Rapid Donning Method for Astronaut Boots

Enabling Description: A method for donning astronaut boots in a zero-gravity environment, where stabilization and precise alignment are challenges. The boot features internal tethers and an active stabilizer. The method comprises: (a) engaging the boot's pre-aligned docking interface with a suit leg attachment point, thereby securing the boot's sole; (b) guiding the foot into the boot's opening using internal suit foot guides; (c) the foot's bottom portion making controlled contact with a lightweight, rigid carbon-composite stabilizer. This contact initiates a spring-loaded, dampened pivoting motion of the stabilizer, facilitated by the low-friction environment. Simultaneously, the top portion of the foot contacts an elastic element within the upper, which actively expands via internal pneumatic channels to accommodate entry. (d) Upon full insertion, micro-magnets within the boot's internal structure provide initial passive retention, while the stabilizer returns to its non-pivoted state and the elastic element contracts, providing a snug fit without relying on gravity.

stateDiagram
    state "Boot Undocked" as Undocked
    state "Boot Docked & Stabilized" as Docked
    state "Foot Insertion In Progress" as Inserting
    state "Foot Fully Inserted & Secured" as Secured

    Undocked --> Docked : Docking Interface Engaged
    Docked --> Inserting : User Guides Foot
    Inserting --> Inserting : Foot Bottom Contacts Stabilizer (Pivots)
    Inserting --> Inserting : Foot Top Contacts Elastic Element (Expands)
    Inserting --> Secured : Full Insertion Detected
    Secured --> Docked : Stabilizer Returns, Elastic Contracts
    Secured --> Undocked : Undock Boot

3. Cross-Domain Application (Method Focus)

Derivative 10.5: Rapid-Entry Method for Emergency Medical Splint Application

Enabling Description: This method applies to the rapid application of an emergency medical splint (e.g., for ankle or lower leg fractures). The splint is designed with a rigid structural frame (analogous to the shoe's stabilizer) around the posterior aspect and an elastic compression sleeve (analogous to the elastic element). The method involves: (a) orienting the patient's injured limb to align with the splint opening; (b) gently guiding the distal end of the limb (analogous to the first portion of the foot) into the splint; (c) the limb's posterior aspect contacting the rigid splint frame's elevated portion, which is designed to pivot slightly outward under gentle pressure, creating a wider entry channel. Simultaneously, the limb's anterior aspect contacts the elastic compression sleeve, which temporarily expands to facilitate entry. (d) Once the limb is fully seated, the splint frame returns to its original position, and the elastic sleeve contracts to provide initial stabilization, allowing for quick and secure immobilization prior to definitive treatment.

sequenceDiagram
    participant MedicalPersonnel
    participant InjuredLimb
    participant EmergencySplint
    participant SplintFrame
    participant CompressionSleeve

    MedicalPersonnel->>InjuredLimb: Orient Limb to Splint
    MedicalPersonnel->>EmergencySplint: Guide Distal Limb into Splint
    InjuredLimb->>SplintFrame: Posterior Contacts, Pivots Outward
    InjuredLimb->>CompressionSleeve: Anterior Contacts, Temporarily Expands
    MedicalPersonnel->>EmergencySplint: Seat Limb Fully
    SplintFrame->>EmergencySplint: Returns to Original Position
    CompressionSleeve->>EmergencySplint: Contracts (Initial Stabilization)
    MedicalPersonnel->>EmergencySplint: Splint Applied Rapidly

Derivative 10.6: Rapid-Entry Method for Canine Protective Paw Wear

Enabling Description: A method for rapidly donning a protective paw boot onto a dog, particularly for working dogs or those with paw injuries. The paw boot features a rigid, articulated paw stabilizer (e.g., molded polymer) at the caudal aspect of the paw and an elasticized cuff. The method comprises: (a) holding the dog's paw above the boot opening; (b) inserting the paw's distal digits (first portion) into the opening; (c) the paw's plantar surface contacting the elevated portion of the paw stabilizer, causing it to pivot rearward (e.g., with a living hinge or spring mechanism). Concurrently, the paw's dorsal aspect contacts the elasticized cuff, which expands the opening. (d) Fully inserting the paw, allowing the stabilizer to rebound and the cuff to contract, providing a snug, secure fit for active movement. The internal foam liner provides comfort and prevents chafing.

flowchart TD
    A[Hold Paw] --> B{Insert Paw Distal Digits};
    B --> C[Paw Planter Contacts Stabilizer (Pivots)];
    C --> D[Paw Dorsal Contacts Elastic Cuff (Expands)];
    C & D --> E[Fully Insert Paw];
    E --> F[Stabilizer Rebounds];
    E --> G[Elastic Cuff Contracts];
    F & G --> H[Secure Paw Boot];

4. Integration with Emerging Tech (Method Focus)

Derivative 10.7: AI-Guided, Haptic Feedback Donning Method

Enabling Description: A method for donning rapid-entry footwear augmented with AI and haptic feedback for optimized user guidance. The shoe contains micro-vibrators embedded in the upper and stabilizer, controlled by an AI-powered micro-controller analyzing real-time pressure sensor data from the footbed and strain gauges on the stabilizer. The method involves: (a) initiating foot insertion; (b) as the foot contacts the stabilizer and elastic element, the AI algorithm calculates the optimal foot trajectory and pressure distribution for efficient donning. (c) The micro-controller then provides haptic feedback (e.g., vibrations) to the user's foot, guiding them to adjust their foot's angle or pressure to maximize stabilizer pivoting and elastic element expansion. For example, a stronger vibration on the medial side might indicate the need to shift weight laterally. (d) The haptic feedback ceases once optimal insertion parameters are met, and the shoe confirms successful donning. This is particularly useful for users with limited mobility or sensory perception.

sequenceDiagram
    participant User
    participant Foot
    participant ShoeSensors
    participant AI_Controller
    participant HapticFeedback
    participant Stabilizer
    participant ElasticElement

    User->>Foot: Start Insertion
    Foot->>ShoeSensors: Pressure/Strain Data
    ShoeSensors->>AI_Controller: Real-time Input
    AI_Controller->>AI_Controller: Process Data, Calculate Optimal Trajectory
    AI_Controller->>HapticFeedback: Send Haptic Commands
    HapticFeedback->>User: Vibrate Shoe (Guide Foot)
    User->>Foot: Adjust Foot Based on Haptic Feedback
    Foot->>Stabilizer: Pivot Action
    Foot->>ElasticElement: Expansion Action
    AI_Controller->>AI_Controller: Monitor Progress
    AI_Controller->>HapticFeedback: Stop Haptic Feedback (Optimal Insertion Achieved)

5. The "Inverse" or Failure Mode (Method Focus)

Derivative 10.8: Low-Power/Manual Override Donning Method

Enabling Description: A method for donning rapid-entry footwear in a low-power or failed-system state (e.g., when battery for active components is depleted, or an electronic fault). The rapid-entry shoe is designed with a passive spring-loaded pivoting stabilizer and a mechanically elastic upper. The method involves: (a) inserting the first portion of the foot, applying deliberate, slightly increased downward and forward pressure to overcome the passive resistance of the stabilizer's pivot mechanism; (b) manually guiding the foot's bottom portion firmly against the elevated portion of the stabilizer, forcing it to pivot rearward via mechanical leverage rather than active assistance. Simultaneously, the top portion of the foot must be pressed against the elastic element, which relies solely on its inherent material stretch for expansion, requiring more force from the user. (c) The foot is fully inserted, and the stabilizer and elastic element return to their default, passive retention positions. This method ensures functionality even without active power, albeit with increased user effort.

flowchart TD
    A[Start Manual Insertion] --> B{Apply Increased Force};
    B --> C[Foot Contacts Stabilizer (Manual Pivot)];
    B --> D[Foot Contacts Elastic Element (Manual Stretch)];
    C & D --> E[Overcome Passive Resistance];
    E --> F[Fully Insert Foot];
    F --> G[Stabilizer Returns (Passive)];
    F --> H[Elastic Element Contracts (Passive)];
    G & H --> I[Heel Retained (Low-Power Mode)];

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Combination Prior Art Scenarios

Here are three scenarios where the technology of US12274325 can be combined with existing open-source standards to establish further prior art.

1. AI-Optimized Fit & Comfort with ONNX Runtime Integration

Scenario: A rapid-entry shoe (as per US12274325) incorporates an AI model (e.g., a neural network) that learns user-specific foot dynamics during donning and wear. This model, developed using open-source frameworks like TensorFlow or PyTorch, is converted to the Open Neural Network Exchange (ONNX) format. The ONNX model is then deployed and executed on a low-power embedded microcontroller (e.g., using ONNX Runtime for embedded devices) within the shoe. The AI optimizes the responsiveness of smart materials in the stabilizer (e.g., electrorheological fluids) and elastic elements to provide a custom "rebounding fit" for each user. This combines the core rapid-entry and stabilization features with an open-source standard for AI model deployment.

2. IoT Sensor Data Telemetry using MQTT and Eclipse Paho

Scenario: The rapid-entry footwear (as per US12274325, with enhancements like Derivative 1.8) integrates an array of biometric and mechanical sensors (e.g., pressure, gait, temperature). The sensor data, including donning event timestamps and heel retention force, is collected and formatted according to a simple JSON schema. This data is then transmitted wirelessly using the Message Queuing Telemetry Transport (MQTT) protocol, an open-source messaging standard for IoT devices. The shoe's embedded module uses an open-source client library like Eclipse Paho MQTT Client to publish data to a local or cloud-based MQTT broker, enabling real-time monitoring, predictive maintenance for shoe components, or performance analytics, adhering to open IoT communication standards.

3. 3D-Printed Modular Stabilizer and Liner Components with ASTM F2792 Compliance

Scenario: The rigid stabilizer and the foam liner (as described in US12274325) are designed as modular, interchangeable components, precisely manufactured using Additive Manufacturing (3D printing) techniques. The design files for these components are stored and distributed in an open-source format like Standard Tessellation Language (STL) or Additive Manufacturing File Format (AMF). The materials and manufacturing process (e.g., selective laser sintering of Nylon 12 for the stabilizer, fused deposition modeling of flexible thermoplastic polyurethane for the liner) are developed and qualified in accordance with ASTM F2792 – Standard Terminology for Additive Manufacturing Technologies. This allows for customized and on-demand production of replacement parts or personalized fits for the rapid-entry footwear, leveraging open standards in additive manufacturing and material science.