DCT
1:24-cv-01218
Wirtz Mfg Co Inc v. Mac Engineering Equipment Co Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Wirtz Manufacturing Company, Inc. (Michigan)
- Defendant: MAC Engineering and Equipment Company, Inc. (Michigan)
- Plaintiff’s Counsel: Reising Ethington PC
- Case Identification: Wirtz Manufacturing Company, Inc. v. MAC Engineering and Equipment Company, Inc., 1:24-cv-01218, W.D. Mich., 11/15/2024
- Venue Allegations: Plaintiff alleges venue is proper because Defendant resides in the district, maintains a regular and established place of business in the district, and has committed alleged acts of patent infringement in the district.
- Core Dispute: Plaintiff alleges that Defendant’s automated battery grid pasting machines and systems infringe a patent related to closed-loop feedback control for applying a uniform thickness of paste material to battery grids.
- Technical Context: The technology relates to the industrial manufacture of lead-acid batteries, where precise, automated application of electrochemically active paste is critical for battery performance and cost-effective production.
- Key Procedural History: The complaint alleges that Plaintiff sent a letter to Defendant on April 16, 2024, providing notice of the alleged infringement. This notice may be relevant to any subsequent claims for willful infringement.
Case Timeline
| Date | Event |
|---|---|
| 2012-09-24 | U.S. Patent No. 9,744,552 Priority Date |
| 2017-08-29 | U.S. Patent No. 9,744,552 Issues |
| 2024-04-16 | Plaintiff sends notice letter to Defendant |
| 2024-11-15 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,744,552 - "Battery Grid Pasting Machine and System" (Issued August 29, 2017)
The Invention Explained
- Problem Addressed: The patent describes the challenge of applying a consistent, uniform layer of electrochemically active paste onto lead alloy grids during battery manufacturing (Compl. ¶9; ’552 Patent, col. 1:28-34). Prior methods often required manual adjustments, leading to variations in paste thickness, material waste, and potentially suboptimal battery performance, a particular concern for newer sealed battery technologies (Compl. ¶11; ’552 Patent, col. 7:46-67).
- The Patented Solution: The invention is an automated system that creates a closed-loop feedback mechanism to control paste thickness (’552 Patent, Abstract). A machine dispenses paste from a hopper onto grids carried by a conveyor; a sensing station located "downstream" measures a property of the pasted grid, such as its thickness or weight; and a controller uses this measurement to automatically actuate motors that adjust the gap between the hopper and the conveyor, thereby regulating the amount of paste applied (’552 Patent, col. 2:40-62; Fig. 1).
- Technical Importance: This automated control system was designed to provide a more "accurate, precise, efficient, and consistent" paste application process, which the patent notes was "often required in recently favored battery technologies such as sealed batteries" to improve quality and lower manufacturing costs (’552 Patent, col. 2:50-59).
Key Claims at a Glance
- The complaint asserts independent claim 16 (Compl. ¶22, ¶26).
- The essential elements of independent claim 16 are:
- A battery grid pasting machine comprising a hopper with an orifice plate and a conveying apparatus.
- A first and a second servo rotary actuator, each coupled to the hopper via a connector.
- A sensing station located downstream of the hopper that senses "a value of at least the thickness of the battery paste."
- A controller electrically coupled to the actuators and the sensing station, which receives the sensed value and controls the actuators "based at least in part thereupon" to vary the space between the hopper and conveyor, thus controlling paste application.
- The complaint states that infringement is not necessarily limited to claim 16, reserving the right to assert other claims (Compl. ¶26).
III. The Accused Instrumentality
Product Identification
The accused instrumentality is the "MAC Steel Belt Paster," identified as a type of battery grid pasting machine and system (Compl. ¶24; p. 6).
Functionality and Market Context
The complaint, citing Defendant's brochure, alleges the MAC Steel Belt Paster is an automated system for applying a uniform thickness of paste (Compl. ¶24). Its features are described as including an "independently powered paste dispensing hopper featuring Orifice plate type tooling" and a "stainless steel belt" (Compl. p. 6). Crucially, the complaint alleges the system can be equipped with "optional servos to the hopper" and connected to a "laser thickness gauge," which "will close the loop for total automatic control," functionality that is alleged to map directly onto the patent's claims (Compl. p. 7).
IV. Analysis of Infringement Allegations
The complaint provides a claim chart juxtaposing the language of claim 16 with excerpts from Defendant’s marketing brochure for the "MAC Steel Belt Paster" (Compl. pp. 6-7).
’552 Patent Infringement Allegations
| Claim Element (from Independent Claim 16) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a battery grid pasting machine comprising: a hopper having a dispensing end with an orifice plate having an orifice that dispenses battery paste onto and through a grid; and a conveying apparatus moving grids through a space under and across said orifice... | The accused "MAC Steel Belt Paster" uses a "paste dispensing hopper featuring Orifice plate type tooling" and a "stainless steel belt [that] pulls the strip through the hopper." | ¶26, p. 6 | col. 5:45-6:14 |
| a first servo rotary actuator coupled to a first connector coupled to said hopper; | The accused system allegedly offers the option to "[a]dd the optional servos to the hopper." | ¶26, p. 7 | col. 6:15-24 |
| a second servo rotary actuator coupled to a second connector coupled to said hopper; | The accused system allegedly offers the option to "[a]dd the optional servos to the hopper." | ¶26, p. 7 | col. 6:15-24 |
| a sensing station located downstream of said hopper... said sensing station sensing a value of at least the thickness of the battery paste of a pasted battery grid; | The accused system can allegedly "connect... to a laser thickness gauge." | ¶26, p. 7 | col. 4:1-12 |
| a controller electrically coupled to said first and second servo rotary actuators and electrically coupled to said sensing station, and said controller receiving said sensed value and controlling actuation of said servo rotary actuators based at least in part thereupon to vary said generally vertical extent of said space... | The combination of optional servos and a laser thickness gauge "will close the loop for total automatic control." | ¶26, p. 7 | col. 7:1-28 |
Identified Points of Contention
- Scope Questions: The complaint's evidence describes the servo actuators and laser thickness gauge as "optional" components that can be "add[ed]" to the hopper (Compl. p. 7). A primary point of contention may be whether Defendant offers for sale or sells a single, integrated system that contains all the elements of claim 16, or if the allegedly infringing configuration only exists when a customer separately purchases and combines these optional features.
- Technical Questions: The complaint alleges that connecting the servos and gauge "will close the loop for total automatic control" (Compl. p. 7). A factual question for the court will be whether the accused system's controller, when connected to these components, actually performs the claimed function of receiving a sensed thickness value and, based on that value, controlling the actuators to vary the paste application space.
V. Key Claim Terms for Construction
The Term: "controller... controlling actuation... based at least in part thereupon [the sensed value]"
- Context and Importance: This limitation defines the core feedback loop of the invention. The dispute will likely center on whether the accused controller inherently performs this function or is merely capable of being configured by a user to do so. Practitioners may focus on this term because it is central to proving that the accused system functions as the claimed automated, closed-loop system.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the controller in general terms as potentially being a "programmable logic controller (PLC), a digital computer, a programmable microchip, or the like" that can "automate operation" (’552 Patent, col. 7:8-12), which could support a construction that does not require a highly specialized or pre-configured unit.
- Evidence for a Narrower Interpretation: The detailed description explains that the controller "compares the thickness measurement to a predetermined reference thickness value" to determine how to adjust the actuators (’552 Patent, col. 8:31-49). A party could argue this comparative logic is a required function for "controlling... based at least in part" on the sensed value.
The Term: "a sensing station"
- Context and Importance: The infringement allegation relies on a "laser thickness gauge" meeting this limitation. The definition of "station" will be important—whether it requires a particular structure or if any device that performs the sensing function qualifies.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification discloses multiple types of sensors that could comprise a sensing station, including thickness, weight, and moisture sensors, suggesting the term is not limited to a single technology or configuration (’552 Patent, col. 3:56-4:54).
- Evidence for a Narrower Interpretation: Claim 16 specifically requires the station to sense "at least the thickness," and Figure 1A depicts a "thickness sensing station 30" with a specific two-part structure (’552 Patent, Fig. 1A). A party could argue that this context from the preferred embodiment narrows the scope of what constitutes a "station."
VI. Other Allegations
Indirect Infringement
The complaint alleges both induced and contributory infringement. The inducement claim is based on Defendant allegedly "knowingly inducing... its customers to make or use the claimed pasting system" (Compl. ¶29). This theory may rely on evidence from user manuals or marketing materials, such as the cited brochure, that instruct customers on how to combine the "optional" components to create the infringing system. The contributory infringement claim alleges Defendant provides a component "especially made or adapted for infringement" that is not a "staple article of commerce" (Compl. ¶30).
Willful Infringement
The complaint alleges that Defendant had "prior knowledge of the '552 Patent" and that its infringement has been knowing and intentional (Compl. ¶32). This allegation is supported by the specific claim that Defendant was put on notice via a letter dated April 16, 2024 (Compl. ¶33).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central question of product configuration will be whether the "MAC Steel Belt Paster" is offered for sale as a system that meets all limitations of Claim 16 out of the box. The case may turn on whether the "optional" servos and thickness gauge are part of a standard, albeit configurable, offering, or if they are separate products, which would shift the focus to indirect infringement.
- A key issue for indirect infringement will be one of intent and action: if the components are sold separately, what evidence demonstrates that Defendant's marketing, instructions, or support actively encourages customers to combine them in a manner that directly reads on the patented closed-loop control system?
- A core issue for claim construction will be one of functional scope: does the claim limitation "controlling... based at least in part" on a sensed value require an inherent, pre-programmed feedback logic within the controller, or is it met by a system where a general-purpose controller is merely capable of being connected to and configured by a user to perform the claimed function?