Toughbuilt Industries Inc v. Meridian Intl Co Ltd

1. Case Identification

• Case #: IPR2025-01461
• Patent #: 11,986,946
• Filed: August 28, 2025
• Petitioner(s): ToughBuilt Industries, Inc.
• Patent Owner(s): Meridian International Co., Ltd.
• Challenged Claims: 1-16

2. Patent Overview

• Title: Stackable Storage Box
• Brief Description: The ’946 patent discloses a modular, stackable storage box system featuring a connection mechanism for attaching boxes together. The core of the invention is a locking mechanism that includes a spring-loaded "stop part" designed to hold the lock in an unlocked state to facilitate the decoupling of the boxes.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-4, 7-12, and 15 over Li

• Prior Art Relied Upon: Li (Application # 2022/0396985).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Li discloses a latch structure for securely connecting stackable carriers that meets every limitation of the challenged independent claims. Li's "elastic pull latch 3" was mapped to the claimed "first connection part," which includes a mounting body (Li's "stop piece 35"), a movable locking buckle (Li's "pull latch cover 32"), and a first resilient member (Li's "first spring 34"). Critically, Petitioner asserted that Li's "elastic boss 33," biased by a "second spring 36," is a direct analog to the claimed "stop part," which is retractable, extends to hold the latch in an unlocked state, and is compressed in a locked state.

Ground 2: Anticipation of Claims 1-4, 7-12, and 15 over Baruch

• Prior Art Relied Upon: Baruch (Application # 2020/0298392).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Baruch, which discloses a latch mechanism for securing containers, anticipates the same set of claims. Baruch's "latch mechanism 310" was argued to be the claimed "first connection part," comprising a mounting body ("pins 334"), a locking buckle ("latch 314"), and a resilient member ("latch bias 320"). Petitioner mapped Baruch's "stopper/holder 370," biased by "stopper bias 376," to the claimed "stop part." It was argued that Baruch's stopper performs the same functions: it extends to hold the latch in an unlocked state, is compressed when locked, and moves perpendicularly to the sliding path of the locking part.

Ground 3: Obviousness of Claims 5-6 and 13 over Li in view of Burchia and Hammond

• Prior Art Relied Upon: Li (Application # 2022/0396985), Burchia (Application # 2020/0329837), and Hammond (Application # 2023/0340804).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addressed dependent claims requiring the second resilient member to be a torsion spring and the stop part to rotate. Petitioner argued Li teaches the primary system with a generic spring-biased stop part ("elastic boss 33" and "second spring 36"). Burchia was cited for its teaching that various spring types, explicitly including "torsion springs," are known and interchangeable for use in locking mechanisms for stackable boxes. Hammond was introduced to provide specific, well-known implementation details for a torsion spring that biases a pawl (a stop part) to rotate about a fixed shaft.
  • Motivation to Combine: Petitioner asserted a POSITA, starting with Li's design, would be motivated to use a torsion spring for Li’s "second spring 36" as a simple design choice, as taught by Burchia. To implement this known substitution, a POSITA would look to references like Hammond, which show how to mount a torsion spring on a shaft to provide rotational bias to a stop part. The combination would have been a predictable application of known elements to achieve the same function of holding a latch in an unlocked state.
  • Expectation of Success: A POSITA would have a high expectation of success because it involved substituting one known type of spring for another in a conventional locking mechanism to achieve its known function, a predictable design modification.

• Additional Grounds: Petitioner asserted alternative obviousness challenges over Li alone and Baruch alone. Further obviousness grounds combined Li with Davidian (Application # 2021/0221561) to add teachings of projections and recesses for stacking stability (addressing claims 14 and 16). Similar combinations of Baruch with Burchia/Hammond and Baruch with Davidian were also asserted to address the same dependent claims.

4. Key Claim Construction Positions

• The petition highlighted a dispute over the term "stop part" from a related district court case.
  • Petitioner's Position: Petitioner proposed construing "stop part" under §112(f) as a means-plus-function term, or alternatively, as a "combination of a rigid blocking part and a resilient member that extends out from a slot... to physically block the locking part... and that is compressed and retracted."
  • Patent Owner's Position: The Patent Owner argued that "stop part" needed no construction or, alternatively, could be construed as "a spring-biased mechanical interference device."
  • Relevance: Petitioner maintained that the prior art discloses the "stop part" under any of the proposed constructions.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-16 of the ’946 patent as unpatentable.