Patent Claim Preamble Not Limiting, Infringement Not Derailed

Here is a case illustrating the general rule that the preamble of a patent claim is rarely construed as a substantive claim limitation. In Georgetown Rail Equipment Co. v. Holland L.P.¸ No. 2016-2297 (Fed. Cir. Aug. 1, 2017), the Federal Circuit affirmed a claim construction finding that elements of the preamble do not limit the scope of the claimed invention.  

Georgetown owns U.S. Patent 7,616,329, which is directed to digital technology to inspect railroad track tie plates. Georgetown markets products that use lasers and cameras mounted on a rail car to collect and process information about track ties. A jury found that these products infringed claims of the ’329 patent.

Holland purchases track tie and measuring technology from a third party and mounts such equipment on a rail car. Holland collects data with the rail car and stores such data on hard drives. The hard drives are then physically shipped overseas, where the data is processed by a third party.  

Following a claim construction determination by the District Court for the Eastern District of Texas that the preamble did not limit the scope of the claim, a jury found that Holland willfully infringed the ‘329 patent, awarding lost profits and enhanced damages.

Holland appealed the District Court’s claim construction of the preamble of Claim 16 of the ‘329 Patent as not limiting. Claim 16 reads in part:

16. A system for inspecting a railroad track bed, including the railroad track, to be mounted on a vehicle for movement along the railroad track, the system comprising:

at least one processor for analyzing the plurality of images and determining one or more physical characteristics of the said portion of the railroad track bed, the one or more physical characteristics comprising at least a geographic location of the plurality of images along the railroad track bed, …

Holland argued that Claim 16 required that all elements in the claim body be mounted on a vehicle, e.g., that the at least one processor for analyzing the plurality of images must be mounted on the vehicle. Such construction would allow Holland to avoid infringement because its processing was done with a processor separate from the vehicle collecting data. Holland supported its position by pointing to the specification of the ‘329 Patent, which described all embodiments as being vehicle-based. Holland further argued that the preamble was “essential” to understanding the limitations of the claim body. Finally, Holland pointed to statements made during the prosecution of the ‘329 Patent.

The Federal Circuit rejected these arguments. Determining whether the preamble is limiting requires “review of the entire . . . patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim.” Catalina Mktg. Int’l, Inc. v. Coolsavings.com, Inc., 289 F.3d 801, 808 (Fed. Cir. 2002). Generally, the preamble is not a claim limitation. The courts look to a few key principles to determine whether the preamble is an exception to the general rule. These principles include whether the preamble recites an essential structure or step, whether the preamble provides antecedent basis to elements in the claim body, whether the preamble is essential to understand limitations or terms in the claim body, whether the structure or steps in the preamble are underscored as important by the specification, and whether the preamble was relied on to distinguish the invention from prior art during prosecution. Conversely, the preamble is not limiting when it merely states a purpose or intended use for the invention, and where the claim body defines a structurally complete invention.

Here, the Court pointed out that the specification stated that the system can, not must, be mounted to a vehicle, and that the processing and computation of data need not be performed by a device affixed to a vehicle. Further, the court pointed out that the claimed system could be practiced without a vehicle, e.g., by manually carrying the system along the tracks. Finally, the court noted that the prosecution history lacked statements to distinguish the system from the prior art based on mounting the system to a vehicle.

Lessons For Practice

Placing claim elements in the preamble can cause uncertainty in claim scope and provide an area ripe for dispute in litigation. This is not to say that claim elements should never be included in the preamble, but that thorough consideration should be given when doing so, keeping in mind the principles governing when such elements are limiting.