Tsuyoshi Nakamura | June 19, 2013
Douglas Dynamics LLC v. Buyers Products Co.
May 21, 2013
Panel: Rader, Newman, and Mayer. Opinion by Rader. Dissent by Mayer.
Connection between two elements is relatively clear and does not cast heavy doubt. Adding another element allows possible variations in connections among three elements and requires deeper thoughts of a claim drafter. In this case, the CAFC reversed the district court’s narrower claim interpretation of “connected to” in light of its ordinary meaning and the usage in the specification. Judge Mayer dissented from the majority’s claim construction. Contexts of a claim are source for supporting specific claim interpretation. A functional limitation supported a favorable interpretation for patentee and saved a problematic structural limitation from a pitfall.
Claim at issue
Claim 45 of U.S. Patent No. RE 35,700 recites three frames, a mounting frame, an A-frame and a support frame, and connection relationships among three frames. Specifically, the connection relationships are recited as “a support frame connected to the A-frame, then the A-frame and the support frame are connected to the mounting frame.” What is interpreted from these connections? Should the A-frame should be directly connected to the mounting frame (“direct connection”), or should it be indirectly connected to the mounting frame through the support frame (“indirect connection”), or both?
…a mounting frame…,
a support frame connected to the A-frame, and
wherein the A-frame and the support frame are connected to the mounting frame for pivotable movement of the A-frame about a generally horizontally extending pivot axis and for affording removal of the A-frame and the support frame from the mounting frame as a unit so as to leave the mounting frame on the vehicle and behind the bumper.
Defendant Buyers did not dispute that its accused products included an A-frame connected to a mounting frame through a support frame. The products satisfy the “indirect connection” only.
The district court focused on the recitation of “the A-frame and the support frame are connected to the mounting frame” and stated that if the “indirect connection” is covered, a limitation which requires the A-frame to be connected to the mounting frame is superfluous. In other words, the court pointed out that reciting both the A-frame and the support frame are connected to the mounting frame would be redundant unless “direct connection” was intended. The district court proposed that because claim 45 already recited the connection between the A-frame and the support frame, simply reciting a connection between the support frame and the mounting frame would be enough to imply the “indirect connection.”
The CAFC first pointed out that the ordinary meaning of “connected to” includes indirect linkages. The court next stated that the specification used variations of the term “connect” to describe indirect connections (e.g., the blade… is connectable to the mounting frame…through an A-frame). As to the specification, the court further stated that the district court’s narrower interpretation would exclude a preferred embodiment of the invention such as described in Fig. 6. As to the superfluous argument, the court interpreted the “redundant” limitation in view of the functional limitation directly following that limitation, i.e., pivotal movement of the A-frame and removal of the A-frame and the support frame from the mounting frame as a unit. The court found this functional recitation as “functional requirements” for the connection between the mounting frame and the A-frame/support frame unit, and explained that the “functional requirements” for the connection cover the connection of either the A-frame or the support frame, or both, to the mounting frame.
Judge Mayer took a different view as to the part of the specification “the blade… is connectable to the mounting frame…through an A-frame.” Judge Mayer stated that the specification used the word “through” when it specifically described the “indirect connection,” and on the other hand, for the “direct connection,” it simply used the word “connected,” and thus, the specification did not support majority’s view. Judge Mayer also supported the district court’s superfluous argument.
Effect of contexts of the claim
The district court emphasized the fact that claim 45 already recited the connection between the A-frame and the support frame, and in this context, the court examined the meaning of the recitation of the A-frame and the support frame connected to the mounting frame. It seems that the district court focused solely on “structural limitations.” On the other hand, the CAFC found that the context includes a functional limitation. The result seem to have been affected by the contexts that each court found. Context of a claim has been used to support specific claim interpretation. For example, in Seafoss, the court looked into the context of the claims and found that, if the indirect connection was covered, some claim recitations would not make sense. In Ethicon, the court found that the broader interpretation covering indirect connection allowed the claimed “lock mechanism” to be located anywhere, and thus the “connected to” limitation would be meaninglessly empty. The court acknowledged that it could be broadly interpreted in other contexts.
If claim 45 of the ‘700 patent was drafted in accordance with the proposal of the district court by simply reciting a connection between the support frame and the mounting frame, the patentee could have avoided the issue of superfluousness. However, such a recitation would not allow the other interpretation of the “direct connection” between the A-frame and the mounting frame. If a claim drafter desired to cover both the direct and indirect connections, it would be safer to include a clear definition in the specification. Claim 45 of the ‘700 patent was a new claim added by reissue proceedings. In that sense, adding a new definition into the specification could raise a new matter problem. In this specific case, adding two different claims, one of which covers the direct connection and the other covers the indirect connection, would be practical solution. Anyway, relying on the context of a claim would be the last resort after every opportunity for amendment has been exhausted.