Scott Baker v. Billdon LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Scott Baker (California)
  • Defendant: Billdon LLC (dba BILLY FOOTWEAR) (Washington)
  • Plaintiff’s Counsel: Pro Se
• Case Identification: 2:25-cv-10286, C.D. Cal., 02/17/2026
• Venue Allegations: Plaintiff, a California resident, alleges venue is proper in the Central District of California because Defendant, a Washington corporation, has cultivated a significant market presence through strategic "partnerships" with retailers such as Target, Kohl's, and Nordstrom, which have numerous physical stores constituting a "regular and established place of business" within the district.
• Core Dispute: Plaintiff alleges that Defendant’s adaptive footwear products, which feature a wrap-around zipper for ease of entry, infringe six of Plaintiff's U.S. patents directed to this type of footwear technology.
• Technical Context: The technology at issue addresses the adaptive footwear market, specifically for individuals with limited mobility, by enabling a shoe's upper portion to open wide via a zipper, allowing a user to place their foot directly onto the insole rather than sliding it in.
• Key Procedural History: The complaint alleges that Plaintiff sent a series of six cease and desist letters to Defendant, with the first dated January 25, 2019. A new letter was allegedly sent shortly after each of the six patents-in-suit issued, putting Defendant on notice of the patents. This history forms the primary basis for the complaint's allegations of willful infringement.

Case Timeline

Date	Event
2013-06-14	Earliest Priority Date for all Patents-in-Suit (’893, ’796, ’733, ’630, ’806, ’089)
2019-01-15	U.S. Patent No. 10,178,893 Issued
2019-01-25	Cease and Desist Letter Sent Regarding '893 Patent
2020-10-06	U.S. Patent No. 10,791,796 Issued
2020-10-16	Cease and Desist Letter Sent Regarding '796 Patent
2021-11-16	U.S. Patent No. 11,172,733 Issued
2021-11-19	Cease and Desist Letter Sent Regarding '733 Patent
2023-09-12	U.S. Patent No. 11,751,630 Issued
2023-09-18	Cease and Desist Letter Sent Regarding '630 Patent
2023-12-26	U.S. Patent No. 11,849,806 Issued
2024-05-28	U.S. Patent No. 11,992,089 Issued
2024-07-15	Cease and Desist Letter Sent Regarding '089 Patent
2024-08-27	Cease and Desist Letter Sent Regarding '806 Patent
2026-02-17	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,178,893, "SHOE", Issued January 15, 2019

The Invention Explained

• Problem Addressed: The patent describes the difficulty individuals with limited muscular control of their lower extremities face when putting on conventional shoes (U.S. 10,178,893 B1, col. 2:5-11). Forcing a foot into a shoe can cause toes to bend or curl, leading to poor circulation, swelling, and discomfort, particularly for those who may not have the sensation to know their foot is positioned incorrectly (U.S. 10,178,893 B1, col. 2:11-15; U.S. 10,178,893 B1, col. 7:36-40).
• The Patented Solution: The patent proposes a shoe with a unique zipper-based fastener system (U.S. 10,178,893 B1, abstract). The zipper starts at the ankle opening, travels down the side of the shoe, curves around the front toe area near the sole, and continues partially up the other side (U.S. 10,178,893 B1, col. 5:1-8). Unzipping this fastener allows a significant portion of the shoe's upper to fold away from the sole, creating a "large flap" that fully exposes the interior and allows a user to place their foot directly onto the sole from above, ensuring proper toe alignment before closing the shoe (Compl. ¶8; U.S. 10,178,893 B1, col. 5:14-29). The concept is illustrated in the patent's Figures 1 and 2, which show the shoe in closed and open positions (U.S. 10,178,893 B1, figs. 1-2).
• Technical Importance: This design offers a functional solution in the adaptive apparel market, aiming to provide greater independence and health benefits for individuals with mobility challenges (Compl. ¶8).

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. Exhibit 1-CC1).
• Essential elements of Claim 1 include:
  • A sole and a top member defining a space for a foot.
  • A single continuous zipper fastener.
  • The zipper extending from a starting point at a midpoint of the ankle opening on the medial side.
  • The zipper traversing the medial side toward the connection area, continuing across the distal front end portion, and then traversing the lateral side toward the heel.
  • A zipper termination point on the lateral side of the top member.
  • This configuration allows a "fold back portion" of the top member to be folded back to provide foot access when the zipper is open.
• The complaint does not explicitly reserve the right to assert dependent claims, though this is common practice.

U.S. Patent No. 10,791,796, "SHOE", Issued October 6, 2020

The Invention Explained

• Problem Addressed: The '796 Patent, a continuation-in-part of the '893 patent family, addresses the same technical problem of enabling easier and safer foot insertion into shoes for individuals with limited mobility (U.S. 10,791,796 B1, col. 1:13-19).
• The Patented Solution: The solution is functionally identical to that of the '893 patent: a wrap-around zipper that allows the shoe's upper to open into a "large flap" (Compl. ¶43; U.S. 10,791,796 B1, abstract). The primary distinction appears to be in the specific path of the zipper as defined in the claims, seemingly to cover an alternative embodiment or product design (U.S. 10,791,796 B1, col. 5:5-11).
• Technical Importance: As with the '893 patent, the invention provides a key innovation for the adaptive footwear market (Compl. ¶8).

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. Exhibit 1-CC2).
• Essential elements of Claim 1 include:
  • A sole and a top member defining a space for a foot.
  • A single continuous zipper fastener.
  • The zipper extending from a starting point at a midpoint of the ankle opening on the lateral side.
  • The zipper traversing the lateral side toward the connection area, continuing across the distal front end portion, and then traversing the medial side toward the heel.
  • A zipper termination point on the medial side of the top member.
  • This configuration allows a "fold back portion" to provide foot access when open.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 11,172,733, "SHOE", Issued November 16, 2021

• Technology Synopsis: The '733 Patent continues the technology of the parent patents, describing a shoe with a wrap-around zipper that allows the upper to open fully, facilitating easy foot placement for users with limited mobility (Compl. ¶49).
• Asserted Claims: Independent Claim 1 (Compl. Exhibit 1-CC3).
• Accused Features: The accused Billy Footwear products are alleged to infringe by incorporating the patented "large flap" opening mechanism, which utilizes a zipper traversing from the ankle down and around the toe portion of the shoe (Compl. ¶50).

U.S. Patent No. 11,751,630, "SHOE", Issued September 12, 2023

• Technology Synopsis: The '630 Patent covers footwear technology that allows the upper portion to open as a "large flap" via a zipper, exposing the internal space of the shoe to assist users with limited or no movement control in placing their feet (Compl. ¶55). A key feature of this patent's claim is the zipper path dropping "below the connection area embedding in the sole" (U.S. 11,751,630 B1, claim 1).
• Asserted Claims: Independent Claim 1 (Compl. Exhibit 1-CC4).
• Accused Features: The accused products are alleged to infringe by utilizing a zipper-based opening system that creates a large flap, consistent with the technology described in the patent (Compl. ¶56).

U.S. Patent No. 11,849,806, "SHOE", Issued December 26, 2023

• Technology Synopsis: The '806 Patent protects a footwear design where a zipper allows the shoe's upper to open into a flap, thereby exposing the shoe's interior for easy "reverse entry" foot placement (Compl. ¶61). This patent family member adds claims related to expandable areas to accommodate ankle braces (U.S. 11,849,806 B1, abstract).
• Asserted Claims: Independent Claim 2 (Compl. Exhibit 1-CC5).
• Accused Features: The complaint alleges that Defendant's footwear products incorporate the patented flap-opening technology enabled by a wrap-around zipper (Compl. ¶62).

U.S. Patent No. 11,992,089, "SHOE WITH EXPANDABLE TOP", Issued May 28, 2024

• Technology Synopsis: The '089 Patent describes a shoe with a wrap-around zipper for creating a "large flap" opening, and further includes claims directed at an expandable top, such as a "vertical split" with expandable material, to accommodate foot or ankle braces (Compl. ¶67; U.S. 11,992,089 B1, claim 13).
• Asserted Claims: Independent Claim 13 (Compl. Exhibit 1-CC6).
• Accused Features: The Defendant's footwear products are accused of infringing by employing the patented zipper-enabled flap opening system (Compl. ¶68).

III. The Accused Instrumentality

Product Identification

• The complaint identifies a wide range of products sold under the "Billy Footwear" brand and various sub-category labels, such as "Billy Classic High," "Billy CS High," "Billy Short wrap Low Tops," "Billy Lugs II," and numerous others (Compl. ¶¶10; Compl. ¶¶13-35).

Functionality and Market Context

• The accused products are a line of adaptive footwear featuring a zipper that traverses from the ankle area, down one side, around the toe box, and partially up the other side (Compl. ¶9). The complaint alleges that when unzipped, the top portion of the shoe "is able to be flipped open...as a 'large flap'," revealing the entire internal area of the shoe (Compl. ¶9). This functionality is central to the infringement allegations and is depicted in several complaint exhibits, such as the photographs of the "Red BILLY Classic DIR II High" shoe shown in both closed and open configurations (Compl. ¶13). Another image of the "Tan BILLY Lug II" boot clearly demonstrates the same flap-opening mechanism (Compl. ¶16). Defendant's products are allegedly sold worldwide through its website and through major U.S. retail partners with a significant presence in California, including Nordstrom and Target (Compl. ¶11). The complaint provides a screenshot from Defendant's website showing a store locator with retail locations in the Central District of California (Compl. ¶11).

IV. Analysis of Infringement Allegations

'893 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a single fastening means in the form of one continuous zipper fastener (5)	The accused products use a single continuous zipper fastener.	Compl. Ex. 1-CC1, p. 36	col. 5:1-8
extending from a starting point (5A) at a midpoint...on the medial side of the ankle opening (4C)	The accused products' zipper starts at the ankle opening on the lateral side, which the complaint alleges is an "insubstantial difference" from the claimed medial side start.	Compl. Ex. 1-CC1, p. 36	col. 9:55-59
traversing the medial side of the top member (2D)...becomes the distal...front end portion (2A)	The accused products' zipper traverses the lateral side, which the complaint alleges is a "mirroring" of the claimed path and an "obvious variation."	Compl. Ex. 1-CC1, p. 36	col. 9:59-64
continuing across the distal front end portion of the shoe (2A) at the connection area...becomes the lateral side of the top member (2C)	The accused products' zipper continues across the front of the shoe to the medial side, which is alleged to be an "insubstantial difference."	Compl. Ex. 1-CC1, p. 36-37	col. 10:1-5
then traversing the lateral side of the connection area...to a zipper termination point (5B) located midway...on the lateral side of the top member (2C)	The accused products' zipper traverses the medial side to a termination point on the medial side, which the complaint alleges is a "mirroring" of the claimed path.	Compl. Ex. 1-CC1, p. 37	col. 10:5-15
such that the fold back portion of the top member (2F) is movable...to provide foot access to the space when the zipper fastener is open,	The zipper allows the fold back portion of the top member to be folded back, providing foot access to the internal space of the shoe.	Compl. Ex. 1-CC1, p. 37-38	col. 10:16-31

• Identified Points of Contention:
  • Scope Questions: The primary point of contention for the '893 Patent is based on the Doctrine of Equivalents. The complaint alleges that the accused product's zipper path is a "mirror image" of the path recited in Claim 1 (starting on the lateral side and terminating on the medial side, rather than the claimed medial-to-lateral path) (Compl. Ex. 1-CC1, p. 36). A central question for the court will be whether this "mirrored" configuration performs substantially the same function in substantially the same way to achieve substantially the same result.

'796 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a single fastening means in the form of one continuous zipper fastener (5)	The accused products use a single continuous zipper fastener.	Compl. Ex. 1-CC2, p. 41	col. 5:2-9
extending from a starting point (5A) at a midpoint...on the lateral side of the ankle opening (4C)	The accused products' zipper starts on the lateral side of the ankle opening, allegedly "forward of the midpoint," which the complaint argues is an "obvious variation."	Compl. Ex. 1-CC2, p. 41	col. 10:3-8
traversing the lateral side of the top member (2D)...becomes the distal front end portion (2A)	The accused products' zipper traverses the lateral side of the shoe from the ankle opening down towards the toe area.	Compl. Ex. 1-CC2, p. 41	col. 10:8-14
continuing across the distal front end portion of the shoe (2A) at the connection area, to where the distal...becomes the medial side of the top member (2D)	The accused products' zipper continues across the front of the shoe and transitions to the medial side of the top member.	Compl. Ex. 1-CC2, p. 41-42	col. 10:15-19
then traversing the medial side above the connection area...to a zipper termination point (5B) located midway...on the medial side of the top member (2D)	The accused products' zipper continues up the medial side to a termination point located on the medial side of the top member.	Compl. Ex. 1-CC2, p. 42	col. 10:19-29
such that the fold back portion of the top member (2F) is movable...to provide foot access to the space when the zipper fastener is open,	The zipper allows a fold back portion of the top member to be folded away from the sole, providing access to the shoe's interior.	Compl. Ex. 1-CC2, p. 42-43	col. 10:30-46

• Identified Points of Contention:
  • Scope Questions: While Claim 1 of the '796 Patent appears to track the lateral-to-medial path of the accused products, the complaint alleges infringement for the starting point under the Doctrine of Equivalents, stating the accused product's zipper begins "forward of the midpoint" of the ankle opening (Compl. Ex. 1-CC2, p. 41). This raises the question of whether "at a midpoint" requires a precise location or can be interpreted to cover a location in the general vicinity of the middle.

V. Key Claim Terms for Construction

'893 Patent, Claim 1

• The Term: "extending from a starting point...on the medial side of the ankle opening"
• Context and Importance: This term is critical because the complaint alleges infringement under the Doctrine of Equivalents by a product that allegedly starts on the opposite (lateral) side (Compl. Ex. 1-CC1, p. 36). The construction of "on the medial side" will determine whether this is a strict locational requirement that forecloses literal infringement and frames the equivalents analysis.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party may argue that the specification's focus is on the overall function of creating a "flap" to "provide easy access to the space from the front of the shoe" ('893 Patent, col. 4:33-36). This purpose-oriented language could suggest that the specific starting side is a less critical detail than the overall result.
  • Evidence for a Narrower Interpretation: The claim language is specific, and the patent's figures consistently depict the zipper originating on the medial side (e.g., '893 Patent, fig. 1). A party may argue that this consistent disclosure defines the scope of the invention and limits the term to its plain meaning.

'796 Patent, Claim 1

• The Term: "at a midpoint"
• Context and Importance: The complaint alleges the accused product's zipper starts "forward of the midpoint," making this an infringement dispute under the Doctrine of Equivalents (Compl. Ex. 1-CC2, p. 41). The case may turn on whether "at a midpoint" means precisely at the geometric center or more generally in the middle region of the ankle opening's side.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term is not explicitly defined in the patent. A party could argue that in the context of a flexible item like a shoe, "at a midpoint" should be given a practical, less-rigid interpretation meaning "in the vicinity of the middle."
  • Evidence for a Narrower Interpretation: A party could argue that "midpoint" has a plain and ordinary meaning of a precise central point. The patent's drawings, such as Figure 1 of the parent '893 patent, show the zipper starting roughly in the middle of the side of the ankle opening, which could be argued to support a more specific location.

VI. Other Allegations

• Indirect Infringement: The complaint does not contain separate counts for indirect infringement. However, it requests an order enjoining Defendant's "agents, ... retailers, wholesalers, and all other persons acting in concert with any of them," which suggests a potential basis for an indirect infringement theory (Compl. ¶92).
• Willful Infringement: The complaint alleges willful infringement for all six asserted patents (Compl. ¶¶72-89). The allegations are based on Defendant's alleged pre-suit knowledge of the patents. The complaint claims that Plaintiff sent Defendant a cease and desist letter after each patent issued, beginning with a letter dated January 25, 2019, regarding the '893 Patent (Compl. ¶74). The complaint alleges that Defendant's continued infringement despite this series of notices was deliberate and constitutes reckless disregard of Plaintiff's patent rights (Compl. ¶¶74; Compl. ¶¶77; Compl. ¶¶80; Compl. ¶¶83; Compl. ¶¶86; Compl. ¶¶89).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue for the '893 patent will be one of infringement by equivalents: can the accused product's lateral-to-medial zipper path be found to be an insubstantial variation of the claimed medial-to-lateral path, or did the patentee limit the invention to the specific "un-mirrored" configuration?
• A key question for the '796 patent and its successors will be one of literal scope: does the term "at a midpoint," as used to describe the zipper's starting point, require a precise geometric location, or can it be construed to cover a starting point "forward of the midpoint" as alleged in the complaint?
• A central evidentiary question will concern willfulness: given the documented history of six separate cease and desist letters sent over a multi-year period, what evidence will be presented regarding Defendant's state of mind and any good-faith belief of non-infringement or invalidity it may have held?