Robert Bosch Tool Corp v. Delta Power Equipment Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Robert Bosch Tool Corporation (Delaware)
  • Defendant: Delta Power Equipment Corporation (South Carolina)
  • Plaintiff’s Counsel: Nexsen Pruet, LLC; Brooks Kushman P.C.
• Case Identification: 7:21-cv-02107, D.S.C., 11/29/2021
• Venue Allegations: Venue is alleged to be proper in the District of South Carolina because Defendant is a South Carolina corporation headquartered in Spartanburg, within the district.
• Core Dispute: Plaintiff alleges that Defendant’s "CRUZER" line of sliding miter saws, which use a hinged arm mechanism, infringes a patent related to a compact, angled glide hinge assembly.
• Technical Context: The technology at issue involves linkage systems for sliding miter saws, designed to replace traditional guide rods to reduce the tool's weight and operational footprint.
• Key Procedural History: The complaint alleges that Plaintiff formally notified Defendant of its infringement of the patent-in-suit on March 12, 2020, over a year and a half before filing the lawsuit.

Case Timeline

Date	Event
2015-04-17	’345 Patent Priority Date
2019-02-19	’345 Patent Issue Date
2020-03-12	Defendant formally notified of infringement
2021-11-29	Complaint Filing Date

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

U.S. Patent No. 10,207,345 - "Miter Saw Having An Angled Glide Hinge"

• Patent Identification: U.S. Patent No. 10,207,345, "Miter Saw Having An Angled Glide Hinge", issued February 19, 2019.

The Invention Explained

• Problem Addressed: The patent’s background section states that conventional sliding miter saws use linear guide assemblies with rods and bushings that are heavy, expensive, and require significant clearance space behind the saw for the rods to extend ('345 Patent, col. 1:30-50). This increases the saw's overall footprint and limits where it can be placed, such as against a wall ('345 Patent, col. 1:45-50).
• The Patented Solution: The invention is a compact hinge assembly that guides the saw head in a linear path without using traditional slide rods. It employs two pairs of linkages (a "first linkage assembly" and a "second linkage assembly") that connect the saw's base to its upper support assembly ('345 Patent, Abstract). The key innovation is that each linkage assembly is configured to pivot within its own distinct plane, where these planes are angled, or "transverse," to the workpiece surface ('345 Patent, col. 10:13-39). This angled arrangement allows the linkages to fold and unfold efficiently, guiding the saw head linearly while collapsing into a compact form when retracted ('345 Patent, col. 8:10-24).
• Technical Importance: This design allows for a sliding miter saw with a long cutting capacity to have a significantly smaller rear clearance requirement, enabling it to be used in tighter spaces ('345 Patent, col. 9:26-31).

Key Claims at a Glance

• The complaint asserts independent claim 1 and dependent claims 2-9 ('Compl. ¶25).
• Independent Claim 1 of the ’345 Patent recites:
  • A base assembly with a workpiece support surface.
  • An upper support assembly for a saw blade.
  • A hinge assembly with a first and second linkage assembly, each composed of a pivotably connected front and rear linkage.
  • The upper support assembly moves between a first (retracted) position where the linkages are "substantially perpendicular" to the workpiece surface and a second (extended) position.
  • In the first position, the rear linkages extend in a first plane perpendicular to the workpiece surface, and the front linkages extend in a second plane perpendicular to the workpiece surface.
  • Crucially, the first linkage assembly pivots in a "third plane that is transverse to the workpiece surface plane," and the second linkage assembly pivots in a "fourth plane that is transverse to the workpiece surface plane."

III. The Accused Instrumentality

Product Identification

• The complaint identifies Defendant's "dual bevel miter saws under the name 'Delta CRUZER,'" including models 26-2240 and 26-2250/26-2251, as well as certain saws sold under the "Rigid" brand (Compl. ¶15).

Functionality and Market Context

• The Accused Devices utilize a hinged arm mechanism instead of traditional sliding rails to guide the saw head (Compl. ¶26). Plaintiff cites a promotional video by Defendant that describes these as "robotic arms with 12 individual bearings" (Compl. ¶19). Screenshots from this video are included in the complaint to show the hinged arms allowing the saw blade to "move linearly during the cutting of a workpiece" (Compl. ¶20). This visual shows the arm assembly extending to move the saw head forward over the cutting area (Compl. p. 5, ¶20).
• The complaint alleges that the Accused Devices were "specifically designed to compete" with Plaintiff's own miter saws and are sold through the same hardware retail channels, sometimes on shelves "immediately adjacent" to Plaintiff's products (Compl. ¶16, ¶30).

IV. Analysis of Infringement Allegations

The complaint references an exemplary claim chart (Exhibit B) that was not attached to the filing (Compl. ¶27). The following table summarizes the infringement theory for claim 1 based on the narrative allegations and visuals provided in the complaint.

'345 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a base assembly including a workpiece support surface which defines a workpiece surface plane;	The Accused Devices are miter saws that include a base and table for supporting a workpiece.	¶18	col. 6:8-14
an upper support assembly configured to support a saw blade;	The Accused Devices include an upper assembly that holds the saw blade and motor.	¶18	col. 7:1-3
a hinge assembly including a first linkage assembly and a second linkage assembly... the first front linkage pivotably connected to the first rear linkage...	The Accused Devices have a "hinged arm" connecting the saw blade to the table, which includes a linkage. A visual in the complaint circles this assembly.	¶26	col. 6:20-27
wherein the upper support assembly is configured to move between a first position ... and a second position...	The complaint alleges the hinged arms allow the saw blade to "move linearly during the cutting of a workpiece," which involves movement from a retracted to an extended position. A visual shows the saw in different positions.	¶20	col. 8:3-9
wherein the first front linkage and the first rear linkage pivot in a third plane that is transverse to the workpiece surface plane... and wherein the second front linkage and the second rear linkage pivot in a fourth plane that is transverse to the workpiece surface plane...	The complaint alleges that the "hinged arm" (Compl. ¶26) and "robotic arms" (Compl. ¶19) of the Accused Devices perform the function of the claimed linkage assemblies. The complaint does not contain specific allegations or evidence regarding the precise geometric planes of pivot for these arms.	¶19, ¶26	col. 10:13-39

• Identified Points of Contention:
  • Technical Question: The complaint's infringement theory rests on the allegation that the "hinged arm" of the Delta CRUZER saw is structurally and functionally equivalent to the claimed "hinge assembly." A central question will be whether discovery and expert analysis reveal that the accused arm mechanism actually operates using two distinct linkage assemblies that pivot in separate planes "transverse" to the workpiece surface, as strictly required by the claim. The complaint's visuals show an arm, but do not provide the engineering detail needed to verify this specific geometric constraint.
  • Scope Question: The case may turn on whether the accused "robotic arms" (Compl. ¶19) can be read on the patent's more detailed definition of a hinge assembly comprising specific front and rear linkages. The defense may argue that the overall structure of its arm mechanism differs from the specific two-part linkage assemblies (first and second) recited in the claim.

V. Key Claim Terms for Construction

• The Term: "pivot in a third plane that is transverse to the workpiece surface plane"

• Context and Importance: This limitation appears to be the central inventive concept distinguishing the patent from prior art. The infringement analysis for the entire patent will depend heavily on whether the accused device's linkages are found to pivot in such a "transverse" plane. Practitioners may focus on this term because it is a geometric limitation that is not easily verified from simple product photos and will require technical expert analysis of the accused saw's kinematics.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term "transverse" is not explicitly defined. Plaintiff may argue for a broad, dictionary-style definition, such as any plane that is not parallel or perpendicular. The patent specification contemplates a range of angles, stating the pivot plane can be "between approximately 30 degrees and 60 degrees" ('345 Patent, col. 11:7-13), which may support an interpretation that is not limited to a single, precise angle.
  • Evidence for a Narrower Interpretation: Defendant may argue that the term must be construed in light of the patent's preferred and illustrated embodiments. The specification repeatedly describes and depicts the plane as being at "an angle of approximately 45 degrees" ('345 Patent, col. 11:14-17; col. 6:35-41). This could support an argument that "transverse" requires a substantial angular offset, not just any deviation from parallel or perpendicular.

• The Term: "substantially perpendicular"

• Context and Importance: This term defines the orientation of the linkage assemblies when the saw is in its retracted "first position." The allowable deviation from a true 90-degree angle is critical to determining infringement of this limitation.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The complaint does not provide sufficient detail for analysis of how Plaintiff might argue for a broader interpretation.
  • Evidence for a Narrower Interpretation: The patent specification provides an explicit definition for this term: "substantially perpendicular is defined such that at least 75% of each of the first and second linkage assemblies extend within 10 degrees of perpendicular to the workpiece surface plane" ('345 Patent, col. 2:38-42). This lexicography is likely to be a powerful, if not controlling, piece of intrinsic evidence, limiting the scope of the term to a specific, measurable range.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendant infringes by "promoting or providing for use by others" the Accused Devices (Compl. ¶25). The allegation that Defendant created a YouTube video demonstrating the infringing features could be used to support a claim of induced infringement by showing active encouragement of infringing acts (Compl. ¶19).
• Willful Infringement: The willfulness claim is based on alleged pre-suit knowledge. The complaint asserts that Defendant "was formally notified regarding its infringement of the '345 Patent" on March 12, 2020, and "continued to willfully infringe" thereafter (Compl. ¶22-23).

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

• A core issue will be one of geometric infringement: Will expert evidence demonstrate that the accused Delta CRUZER's "robotic arms" operate with the specific kinematics required by Claim 1, namely two pairs of linkages that each pivot within distinct planes "transverse" to the saw's cutting surface? The general allegations in the complaint will need to be substantiated with detailed technical proof.
• A key evidentiary question will be one of definitional precision: How will the court construe the term "substantially perpendicular"? The analysis will likely focus on the patent's own explicit definition, which requires that at least 75% of the linkage assemblies extend within 10 degrees of perpendicular, a narrow and specific standard that the accused products must meet.