Blackbird Tech LLC v. Milwaukee Electric Tool Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Blackbird Tech LLC d/b/a Blackbird Technologies (Delaware)
  • Defendant: Milwaukee Electric Tool Corporation (Delaware)
  • Plaintiff’s Counsel: Stamoulis & Weinblatt LLC
• Case Identification: 1:19-cv-01256, D. Del., 07/03/2019
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because the Defendant is a Delaware corporation and therefore resides in the district.
• Core Dispute: Plaintiff alleges that Defendant’s power source accessories, which adapt power tool batteries for other uses, infringe a patent related to rechargeable battery accessories.
• Technical Context: The technology concerns adapters that enhance the functionality of high-capacity batteries for cordless power tools, allowing them to serve as portable power sources for other electronic devices.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 9,620,989 - “RECHARGEABLE BATTERY ACCESSORIES”

• Patent Identification: U.S. Patent No. 9,620,989, “RECHARGEABLE BATTERY ACCESSORIES,” issued April 11, 2017.

The Invention Explained

• Problem Addressed: The patent’s background section identifies shortcomings with conventional power tool battery packs, such as the inability for a user to easily determine the remaining charge and their limited utility, being usable only with specific power tools (ʼ989 Patent, col. 1:29-38).
• The Patented Solution: The invention is an accessory that mechanically and electrically connects to a power tool battery pack. This accessory provides a first interface to mate with the battery pack and a second interface (e.g., a USB port or AC plug) to connect to and power a separate device, such as a mobile phone (ʼ989 Patent, Abstract; col. 2:20-26). The accessory effectively transforms a proprietary power tool battery into a multi-purpose portable power source (ʼ989 Patent, col. 5:35-46).
• Technical Importance: The technology extends the utility of proprietary, high-capacity power tool batteries, allowing them to be repurposed for charging common consumer electronics or providing other functions, thereby increasing their value and versatility (ʼ989 Patent, col. 1:41-44).

Key Claims at a Glance

• The complaint asserts independent claim 17.
• Claim 17 requires, in essence:
  • A housing.
  • A first interface for connecting to a power tool battery pack, which includes (a) a mechanical interface with an alignment guide for a slidable connection and (b) an electrical interface.
  • A second interface for connecting to an external "device," which includes (a) a mechanical interface and (b) an electrical interface in communication with the first electrical interface.
• The complaint does not explicitly reserve the right to assert dependent claims, but the prayer for relief requests judgment that Defendant infringed "at least claim 17" (Compl. ¶10; Prayer for Relief ¶A).

III. The Accused Instrumentality

Product Identification

The complaint names the Milwaukee 49-24-2371 M18 Power Source and the Milwaukee 49-24-2310 M12 Power Source as the accused instrumentalities (Compl. ¶10).

Functionality and Market Context

The complaint alleges these products are "cordless power tool battery pack accessories" (Compl. ¶10). It asserts that they are marketed, sold, and offered for sale through Defendant’s website and third-party retailers such as Amazon and Home Depot (Compl. ¶6). The complaint does not provide specific details on the technical operation of the accused products beyond the conclusory statement that they include the interfaces recited in claim 17 (Compl. ¶10).

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or provide detailed factual allegations mapping specific features of the accused products to the limitations of claim 17. The infringement theory is stated in a single paragraph, asserting that the accused products meet the claim requirements for a housing and first and second interfaces (Compl. ¶10). The complaint also pleads infringement under the doctrine of equivalents as an alternative to literal infringement (Compl. ¶11).

No probative visual evidence provided in complaint.

Identified Points of Contention

• Evidentiary Questions: A primary issue will be whether the Plaintiff can develop sufficient evidence to demonstrate that the accused M12 and M18 Power Sources embody each limitation of claim 17. The complaint's lack of specific factual allegations shifts the burden of establishing the infringing functionality entirely to the discovery process.
• Technical Questions: A key technical question will be whether the mechanical connection of the accused products to a Milwaukee-brand battery includes a structure that performs the function of an "alignment guide" as required by the claim. The complaint provides no information on this specific structural element.

V. Key Claim Terms for Construction

• The Term: "alignment guide"
• Context and Importance: This term appears in the "first mechanical interface" limitation of independent claim 17 and defines a specific structural requirement for how the accessory connects to the battery pack. Infringement will depend on whether the connection mechanism of the accused products includes a feature that falls within the scope of this term.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term is not explicitly defined in the specification, which may support an argument that it should be given its plain and ordinary meaning, potentially covering any structure that helps a user align the accessory and battery during connection.
  • Evidence for a Narrower Interpretation: The specification, in a passage describing an embodiment related to dependent claim 13, details the guide as an "elongate, flange-like guide member" that mates with a "channel-like guide member on the battery pack" (ʼ989 Patent, col. 8:51-55). A defendant may argue that this more specific disclosure limits the scope of "alignment guide" to a rail- or flange-type structure, as depicted in Figure 10b (items 526a, 526b).

VI. Other Allegations

• Indirect Infringement: The complaint does not allege any specific facts to support a claim for indirect infringement (induced or contributory). The allegations are focused on direct infringement by Defendant’s making, using, and selling of the accused accessories (Compl. ¶10).
• Willful Infringement: The complaint does not allege pre-suit knowledge of the ʼ989 patent or its infringement. It includes a request in the prayer for relief for a finding that the case is "exceptional under 35 U.S.C. § 285 and awarding enhanced damages," which preserves the issue for potential development based on post-filing conduct (Compl. Prayer for Relief ¶D).

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

• A core issue will be one of evidentiary sufficiency: Given the notice-pleading style of the complaint, can the Plaintiff, through discovery, produce sufficient factual evidence to show that the accused products contain every element of claim 17, particularly the specific "alignment guide" structure?
• The case will also likely involve a significant question of claim construction: Can the term "alignment guide", which is described in the specification with some structural specificity, be construed broadly enough to read on the actual mechanical interface of the accused Milwaukee Power Sources, or is there a fundamental structural difference that places the products outside the scope of the claim?