Prior art — US Patent 11871811

Analysis of Prior Art Cited in U.S. Patent 11,871,811

Based on a review of the prior art references cited by the USPTO examiner during the prosecution of U.S. Patent No. 11,871,811, the following patents are identified as most relevant to the claimed invention. This analysis assesses their potential to anticipate claims under 35 U.S.C. § 102, which requires that a single prior art reference disclose each and every element of a claimed invention.

1. U.S. Patent No. 9,629,416 B2 ("'416 Patent")

Full Citation: M.J. Eull, et al., "Slip-on footwear with fit features," U.S. Patent No. 9,629,416 B2, issued Apr. 25, 2017 (filed Oct. 6, 2009).
Assignee: Red Wing Shoe Company, Inc.
Brief Description: The '416 patent describes slip-on footwear, such as a work boot, designed for easy entry and removal while providing a secure fit. It features a heel counter for support and one or more elastic gore panels near the ankle opening. The design aims to provide the convenience of a slip-on with the snug fit of a laced boot.
Potential Anticipation Analysis:
- This reference is highly relevant as it discloses the core concept of combining a supportive heel structure with elastic elements to facilitate entry.
- Claim 1: The '416 patent discloses a "stabilizer" in the form of a heel counter (Fig. 4, element 30) and "a plurality of elastic elements" (Fig. 4, elements 26, 28) positioned forward of the rear portion. The elastic elements are described as gore panels separated by a non-elastic leather upper. An argument for anticipation could hinge on whether the heel counter disclosed in the '416 patent is considered a "unitary structure extending from the sole portion" as recited in the claim. The drawings suggest it is integrated into the upper and sole assembly, but the precise "unitary" nature and extension "from the sole" would be a key point of contention.
- Claim 10: The '416 patent's elastic gores (26, 28) are shown at different positions and potentially different angles to facilitate the opening of the shoe's throat. An argument could be made that these elements allow the forward portion of the upper to flex for entry. Whether they are explicitly disclosed as having longitudinal axes at "different" angles relative to a vertical axis would require detailed interpretation of the figures and specification.

2. U.S. Patent No. 6,877,252 B2 ("'252 Patent")

Full Citation: W.T. Wilkinson, "Slip-on shoe," U.S. Patent No. 6,877,252 B2, issued Apr. 12, 2005 (filed Apr. 19, 2001).
Assignee: William T. Wilkinson
Brief Description: This patent describes a slip-on shoe with a rigid, L-shaped heel member that is pivotally attached to the sole. The heel member is designed to pivot backward to open the shoe for easy entry and then spring back into place. An elastic band connects the upper part of the heel member to the forward part of the shoe, providing tension to keep the shoe on the foot.
Potential Anticipation Analysis:
- This reference is relevant for its focus on a mechanical heel structure for hands-free entry.
- Claim 1 & 10: The '252 patent's heel member acts as a stabilizer, but it is explicitly described as being pivotally attached, which may contradict the "unitary structure" limitation in the '811 patent's claims. Furthermore, it appears to disclose only a single elastic band (element 30) rather than a "plurality of elastic elements" separated by non-elastic material as required by Claim 1. Therefore, this reference is unlikely to anticipate the claims on its own, but it teaches key concepts of a reinforced heel and elastic components for rapid entry.

3. U.S. Patent Application Publication No. 2017/0303632 A1 ("'632 Application")

Full Citation: M. F. Pratt, "Rapid-entry footwear with rebounding fit system," U.S. Patent Application Publication No. 2017/0303632 A1, published Oct. 26, 2017 (filed Apr. 22, 2016).
Assignee: Kizik Design, LLC
Brief Description: This application, from one of the same inventors and a related company, describes a rapid-entry shoe featuring a rebounding heel. The heel portion is designed to deform or collapse when a foot is inserted and then automatically spring back to its original shape. This is achieved through the use of a flexible and resilient heel counter or frame, often made from materials like spring steel. The goal is to allow hands-free entry without damaging the shoe's structure.
Potential Anticipation Analysis:
- This is a very significant piece of prior art. It discloses a "stabilizer" in the form of a resilient heel frame that extends from the sole portion (see Figs. 4A-4C, element 120). The specification describes this frame as a "single continuous piece of material," which aligns with the "unitary structure" requirement of the '811 patent.
- Claim 1 & 10: The primary difference and novelty of the '811 patent over this reference appears to be the specific configuration of the plurality of elastic elements at the forward part of the shoe. While the '632 application focuses heavily on the rebounding heel mechanism, it does not appear to explicitly describe or claim multiple, separate elastic elements positioned forward of the rear portion and separated by non-elastic material, or elastic elements oriented at different angles to facilitate the opening of the vamp and throat area. An argument against anticipation would focus on the absence of these specific elastic element configurations in the '632 application's disclosure.

4. U.S. Patent No. 11,191,320 B2 ("'320 Patent")

Full Citation: T. A. Aveni, et al., "Footwear with vertically extended heel counter," U.S. Patent No. 11,191,320 B2, issued Dec. 7, 2021 (filed Dec. 28, 2018).
Assignee: Nike, Inc.
Brief Description: The '320 patent discloses an article of footwear with a unique heel counter that extends vertically upward from the sole structure. This extended counter is designed to pivot or flex to create a larger opening for easy foot entry. The design often includes a tensioner or strap that helps return the counter to its original position and secure the shoe.
Potential Anticipation Analysis:
- The '320 patent clearly discloses a form of "stabilizer" that extends from the sole and is designed to aid in entry, similar to the '811 patent.
- Claim 1 & 10: The key question for anticipation is whether the '320 patent also discloses the specific "plurality of elastic elements" as claimed in the '811 patent. The '320 patent's mechanism relies more on the pivoting/flexing of the extended counter itself and a tensioner, rather than multiple elastic gores or inserts in the forward portion of the upper. The drawings (e.g., Fig. 2) show a large opening created by the pivoting counter but do not appear to show the distinct, separated elastic elements as required by Claim 1 or the angular arrangement of Claim 10. Therefore, anticipation by this reference appears unlikely.