The Claims Interpreted Report

Eastern District of Texas Clarifies Distinction Between Claim Interpretation and Factual Findings

By Mark St. Amour

Categories: The Claims Interpreted Report

The Court in Dynocom Industries v. Mainline Automotive Equipment (Docket CV 00553-JRG-RSP, EDTX, Memorandum Opinion and Order dated July 15, 2017) found that a proper claim construction of “co-axially rotate” is “rotate on a common axis.”  The plaintiff advanced a broader construction of the term to account for “some degree of tolerance.”  However, the court noted that such an issue is a question of fact that can be considered after the claims are properly construed.

The claim at issue was claim 1 of US Patent 8,505,374, which reads:

1. A portable on vehicle dynamometer for determining power output

from a drive shaft, comprising:

a rigid frame;

a load shaft rotatably coupled to said rigid frame;

an eddy current brake having a stator connected to said rigid

frame, and a rotor connected to said load shaft;

a hub coupling secured to a first end of said load shaft and connected

directly to the drive shaft for transferring power to the

load shaft, wherein said hub coupling, said drive shaft and

said load shaft co-axially rotate;

said rigid frame having two outwardly extending support arms,

and arm locks which secure said outwardly extending support

arms in fixed positions;

support feet assemblies mounting to respective ones of outer

ends of said support arms; and

two roller assemblies mounted to a lower end of said rigid frame,

providing multidirectional movement of said dynamometer. (emphasis added).

The Plaintiff proposed that “co-axially rotate” should be construed as meaning “the axis of rotation of two rotating structures aligned to a degree sufficient to transfer rotation.” The Defendants proposed that the term should be construed as meaning “rotate on a common axis.”

Plaintiff argued that the term “common axis” does not appear in intrinsic evidence. They further argued that some degree of tolerance is required between the axes, and that there is no requirement for the axes to be perfectly aligned.

Defendants argued that their proposed construction was consistent with Figure 4 of the ‘374 Patent, and was supported by the extrinsic record. They further argued that Plaintiff’s construction was not supported by the intrinsic record, and was at odds with the prosecution history in which “co-axially rotate” was specifically added to avoid anticipation by prior art having shafts that were offset.

The Court ultimately adopted Defendant’s proposed claim construction, holding that “co-axially rotate” means “rotate on a common axis” and pointing out that Plaintiff’s proposed construction would encompass both co-axial and non-co-axial rotation. However, the Court did elaborate on the meaning of “common axis,” explaining that such construction does not require perfect alignment of the axes and that an amount of allowable misalignment is a question of fact, i.e., not an issue to be resolved during claim construction.