The opinion of the court was delivered by: Jeanne E. Scott, U.S. District Judge
This matter comes before the Court for construction of claims in patents held by the Plaintiff, The GSI Group, Inc. (GSI). The Court held a hearing on August 2, 2006, in which the parties presented their positions on the correct construction of disputed claims in Patents Nos. 5,135,271 (the "271 Patent") and 5,400,525 (the "525 Patent") held by GSI. The parties further filed supplemental memoranda. The Court has reviewed the pleadings, the filings by the parties and considered the evidence presented at the hearing and the arguments of counsel and construes the disputed claims as set forth below.
GSI alleges in its Amended Complaint (d/e 5) that Defendant Sukup Manufacturing Co. (Sukup) is infringing on several of its patents covering:
(1) grain tower dryers (Patents Nos. 6,073,364; 6,073,367; 6,076,276, and 6,233,843 (the Grain Tower Dryer Patents); (2) a latching device for grain bin doors (the 271 Patent); and (3) a flame cone for grain bin dryer (the 525 Patent). The parties disagree on the construction of certain of the claims at issue in the 271 Patent and the 525 Patent. The parties have no disagreement on the construction of any claim at issue in the Grain Tower Dryer Patents, including the additional claims that GSI seeks to add in its Amended Complaint. Joint Statement of Claim Construction (d/e 71) (Joint Statement), Tables A-U; Defendant's Response to Plaintiff's Motion for Leave to File Supplemental Statement of Claim Construction (d/e 91).
LEGAL PRINCIPALS A patent consists of written specifications that describe the invention, detailed drawings of the preferred embodiment, and a list of the claims. 35 U.S.C. §§ 111, 112. The claims set forth, "the subject matter which inventor regards as the invention." 35 U.S.C. § 112 ¶2. The scope of the invention protected by a patent is defined by the claims in the patent.
Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005). In this case, the parties disagree on the construction of certain of the claims at issue in the 271 Patent and the 525 Patent.*fn1 The construction of disputed patent claims is an issue of law for the Court to decide. Markman v. Westview Instruments, Inc., 52 F.3d 967, 979-81 (Fed. Cir. 1995).
In construing claims, the Court must first look to the language of the claim. The language of the claim is generally given its clear, ordinary and customary meaning that the language would have to a person of ordinary skill in the art in question at the time of the invention. Phillips, 415 F.3d at 1312. If the meaning of the language is not apparent, the Court should look at intrinsic evidence and extrinsic evidence to ascertain the meaning of ambiguous terms. Intrinsic evidence is the rest of the patent and the prosecution history before the U. S. Patent Office. Extrinsic evidence is expert testimony, dictionaries, treatises and other specialized writings on the subject matter. See Phillips, 415 F.3d at 1312-19 for a detailed discussion of the process of claims construction. Intrinsic evidence is generally more reliable than extrinsic evidence in construing disputed claims. Id. at 1317- Some patent claims are written in a format called "means-plus-function." These claims do not describe the object, structure, or action that make up the invention; rather, these claims describe the invention in terms of a means used to perform a particular function. See e.g., Lockheed Martin Corp. v. Space Systems/Loral, Inc., 324 F.3d 1308, 1318-20 (Fed. Cir. 2003). When the "means-plus-function" format is used, then the "claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof." 35 U.S.C. § 112 ¶6. For purposes of § 112 ¶6, the specification includes the abstract of the invention, summary of invention, detailed description of the preferred embodiment of the invention, and the detailed drawings of the preferred embodiment. Playtex Products, Inc. v. Procter & Gamble Co., 400 F.3d 901, 909 (Fed. Cir. 2005); see e.g., Kegel Co., Inc. v. AMF Bowling, Inc., 127 F.3d 1420, 1427 (Fed. Cir. 1997). The Court must construe the claim to include enough of the structure described in the specifications to perform the function without adding additional structure that would limit the claim. Acromed Corp. v. Sofamor Danek Group, Inc., 253 F.3d 1371, 1382 (Fed. Cir. 2001). The Court must construe the claim in light of the specifications, but may not import limitations into the claim from the specifications. Phillips, 415 F.3d at 1323. If the specifications include more than one structure to perform the function, the claim must be construed to include all of the structures described. Micro Chemical, Inc. v. Great Plains Chemical Co., 194 F.3d 1250, 1258 (Fed. Cir. 1999). In light of these principles, the Court construes the disputed claims as follows.
A. THE 271 PATENT The 271 Patent describes an improved latching mechanism for grain storage bin doors. Grain storage bins are circular structures made of corrugated metal designed to hold large amounts of grain. When the bins are full, the grain presses outward against the walls of the bin. This pressure is called "hoop stress." The bins have doors on the sides to allow access to the interior of the bins when the bins are empty. The problem is how to construct a door that can withstand the hoop stress when the bin is full and still open and close easily when the bin is empty. Joint Statement, Exhibit 5, Patent No. 5,135,271, Background of Invention.
Prior designs used metal pins pointing inward toward the inside of the bin placed in rows on the vertical sides of the door frame. The door was hinged to swing into the bin to open. The door also had holes on either side that would fit over the pins when the door was shut. In this way, the pins would hold the door in place when the grain was placed into the bin and transfer the hoop stress from one side of the door to the other. Id.
The problem that arose from this prior design was that the hoop stress would cause the pins to press up against the side of the holes in the doors and stick. When the grain bins were then emptied, the doors would stick on the pins and be difficult to open. The 271 Patent describes a latching invention that solves this problem by using a latch that creates leverage to force the door off the pins.
The abstract to the 271 Patent states: In order to help disengage the cover member [of the door] from the adjacent bin wall, the latching apparatus includes cam means for providing a mechanical advantage to force the cover member out of engagement with the pins and thereby permit the cover member to open with reduced effort.
Exhibit 5, 271 Patent, Abstract. The Abstract also states that the 271 Patent discloses an "improved pin structure." Id.
The detailed drawings of the preferred embodiment of the invention show a grain bin door divided into three horizontal panels, or cover members, one above the other. Each cover member is hinged to swing into the bin when open. Each cover member has a series of holes lined up vertically on each side of the cover to fit over the row of pins on each side of the door jamb. Each cover member has two latch bars on the outside of the cover member. The two latch bars run horizontally, one above the other, for the width of the cover member. At either end, the latch bar is connected to the cover member by an "L" shaped hook with the latch bar attached to the top of the capital "L" shape and the cover member attached to the base of the "L" shape by a bolt that acts as a pivot point. When the cover member is closed, the L shaped hook fits over a rod or bolt that sticks out from the exterior portion of the door frame that acts as a catch. The cover member is latched by forcing the L shaped hook over the catch so that the L shape is upside down and the catch is caught in the corner formed by the L shape.
The base of the L shape is flat on the bottom, but the top of the base of the L shape is curved. The curved shape runs next to the catch when the latch is opened and closed. The curve is designed so that the catch is closer to the pivot point on the cover member when the latch is closed and farther from the pivot point when the latch is open. The curve acts as a cam when the door is opened and closed. When the latch is closed, the catch runs along the curve of the cam and pulls the pivot point on the cover member closer to the catch. This forces the cover member closer to the catch on the exterior of the door frame. The effect of this is to force the cover member onto the pins and shut. When the latch is opened, the catch runs along the cam surface and forces the pivot point on the cover member farther away. This forces the cover member away from the catch on the door frame and into the empty bin. The effect is to push the cover member off the pins on the inside of the door frame and allow it to swing open into the empty bin.
The detailed drawings also show the improved pin. The pin is fastened to the door frame by a bolt. The portion of the pin that protrudes into the bin is tapered. The portion of the pin that is next to the wall of the bin has a shoulder with a diameter slightly smaller than the rest of the pin. This shoulder fits into the hole in the wall of the bin so that the wall of the bin abuts the shoulder of the pin rather than the bolt that fastens the pin to the wall. This design keeps the wall from pressing directly against the bolt when the bin hoop stresses from a full bin are pushing against the wall. This design reduces the risk that the bolt will break or shear off from the pressure.
The disputed claims discuss the cover member, the cam, the latch, the catch, and the pins. The Court will construe the disputed claim language in order.
The first disputed portion of the claims states: said bulk storage structure including integrating means for engaging said cover means when said cover means is in a closed position to pass hoop stresses placed upon said storage structure through said cover means.
Joint Statement, Table V, at 58. The parties agree that this portion of the claim is written in the "means-plus-function" format. The function described is to pass the hoop stress through the cover over the grain bin door opening. The means described to accomplish this function is a cover member that is integrated into the side wall of the grain bin. The specifications state that this integration of the cover member with the side wall of the bin is accomplished by a set of pins (or protuberances) set in vertical rows on the inside of each side of the door frame and pointing inward. The cover members have a set of holes or bores that go over the pins to attach the cover to the side wall. Attaching the cover to the pins on either side of the door frame effectively integrates the cover member with the side wall so that the hoop stress ...