Cat Tech LLC v. Tubemaster, Inc.

• Decision Date: 28 May 2008
• Docket Number: No. 2007-1443.,2007-1443.
• Parties: CAT TECH LLC (successor to Cat Tech, Inc.), Plaintiff-Appellant, v. TUBEMASTER, INC., Defendant-Appellee.
• Court: U.S. Court of Appeals — Federal Circuit

528 F.3d 871

CAT TECH LLC (successor to Cat Tech, Inc.), Plaintiff-Appellant, v. TUBEMASTER, INC., Defendant-Appellee.

No. 2007-1443.

United States Court of Appeals, Federal Circuit.

May 28, 2008.

David M. Gunn, Beck, Redden & Secrest, LLP and B. Todd Patterson, Patterson & Sheridan, LLP, of Houston, TX, argued for plaintiff-appellant. With them on the brief was Henry M. Pogorzelski Patterson & Sheridan, LLP, of Houston, TX.

Dennis D. Murrell, Middleton Reutlinger, of Louisville, KY, argued for defendant-appellee. With him on the brief was Robert J. Theuerkauf.

Before MAYER and SCHALL, Circuit Judges and YOUNG^*, District Judge.

MAYER, Circuit Judge.

Cat Tech LLC ("Cat Tech") appeals the judgment of the United States District Court for the Southern District of Texas holding that none of four configurations of loading devices manufactured by TubeMaster, Inc. ("TubeMaster") infringes U.S. Patent No. 6,905,660 (the "'660 patent"). We conclude that the district court correctly construed the "spacing" element of claims 3-7 of the '660 patent and that the dispute was sufficiently real and immediate to warrant a declaratory judgment of non-infringement. We therefore affirm.

Background

The relevant facts are largely undisputed. The '660 patent describes a method for using loading devices to place catalyst particles into multi-tube chemical reactors. Multi-tube reactors typically contain thousands of long vertical tubes which are held together at either end by a perforated plate called a tube sheet. Cat Tech's claimed method uses a plurality of plates that are positioned to cover the upper tube-sheet of a chemical reactor. Catalyst is poured over these plates and then swept into the reactor tubes.

Catalyst must be loaded into reactor tubes evenly to prevent catalyst particles from wedging together or "bridging." Bridging occurs when particles enter the reactor tube simultaneously and then "wedge together part way down the tube and leave a void space below them—resulting in unevenly and incompletely loaded tubes." '660 patent col. 1, ll. 38-41. The '660 patent teaches a method of loading reactor tubes that minimizes bridging and can be reconfigured to load reactor tubes of varying sizes.

The '660 patent calls for "a spacing between adjacent plates having a width not greater than the smallest dimension of a single particle to be loaded into the multi-tube reactor." Id. col. 6 ll. 57-60, col. 7 ll. 9-22. This spacing is designed "for collecting dust and partial particles." Id. col.6 ll.60-61, col. 7 ll. 22-23. Independent claims 3 and 4 and dependent claims 5, 6 and 7 provide:

3. A method for loading solid particles into a multi-tube reactor, comprising:

a) positioning a plurality of discrete plates on top of an upper tube sheet of the multi-tube reactor, whereby the plates rest on and substantially cover at least a portion of the upper tube-sheet and provide a spacing between adjacent plates having a width not greater than the smallest dimension of a single particle to be loaded into the multi-tube reactor, the spacing for collecting dust and partial particles, wherein each plate comprises: an aperture that corresponds to a corresponding reactor tube and has a diameter not greater than 95% of the inner diameter of the corresponding reactor tube and not smaller than 1.1 times the greatest dimension of a single particle to be loaded into the corresponding reactor tube; and means for holding the aperture in correspondence with the corresponding reactor tube;

b) pouring the particles over at least a portion of the plurality of plates covering the tube-sheet;

c) sweeping the particles through the apertures in the plates into the corresponding reactor tubes, whereby the particles fill the reactor tubes in a uniform manner and bridging is avoided;

d) removing residual particles and any dust remaining on the plates and in the spacing between adjacent plates; and

e) removing the plurality of plates.

4. A method for loading solid particles into a multi-tube reactor, comprising:

a) positioning a plurality of discrete plates on top of an upper tube sheet of the multi-tube reactor, whereby the plates substantially cover at least a portion of the upper tube-sheet and each plate has a shape that provides a spacing between adjacent plates having a width not greater than the smallest dimension of a single particle to be loaded into the multi-tube reactor, the spacing for collecting dust and partial particles;

b) pouring the particles over at least a portion of the plurality of plates covering the tube-sheet;

c) sweeping the particles through apertures in the plates into reactor tubes of the multi-tube reactor, whereby a size of the apertures is selected for filling the reactor tubes with the particles in a uniform manner and avoiding bridging;

d) removing residual particles and any dust remaining on the plates and in the spacing between adjacent plates; and

e) removing the plurality of plates.

5. The method of claim 4, wherein the positioning the plurality of plates comprises inserting fixing means of the plates into a top of reactor tubes of the multi-tube reactor to provide for alignment of apertures in the plates with corresponding reactor tubes.

6. The method of claim 4, wherein the sweeping the particles is performed mechanically.

7. The method of claim 4, wherein the sweeping the particles is performed manually.

'660 patent col.6 ll.52-67, col.7 ll.1-23, col.8 ll.1-21.

The '660 patent is a divisional of a parent application which was issued as U.S. Patent No. 6,409,977 (the "'977 patent"). Initially, the independent claims of the '977 patent did not contain a spacing element. Instead, a single dependent claim contained a limitation requiring the distance between neighboring plates to be "smaller than the greatest dimension of a single particle to be loaded." In addition to rejecting the independent claims, the examiner rejected the dependent claim stating:

[P]roviding a distance between the neighboring segmented plates was well known in the analogous art at the time of the invention for the purpose of allowing for plate expansion. It would have been obvious to one of ordinary skill in the art at the time the invention was made to provide a distance between the neighboring polygonal plates, for the purpose of allowing for plate expansion. As the specification is silent to unexpected results it would have been obvious to one of ordinary skill in the art at the time the invention was made to provide any distance between the neighboring plates, including a distance being smaller than the greatest dimension of a single particle to be loaded.

Office Action of the Patent and Trademark Office 8 (May 23, 2000).

Cat Tech then canceled the dependent claim and amended the independent claims to include a limitation requiring "an inter-plate spacing having a width not greater than the smallest dimension of a single particle to be loaded into said reactor, said inter-plate spacing effective in collecting dust and partial particles." In distinguishing its invention from the prior art, Cat Tech stated:

Adjacent plates do not touch fully, but are separated by a gap, each gap having a width that is less than the smallest dimension of a particle to be loaded. The gaps are highly effective in collecting dust and partial particles, both of which are undesirable....

None of the prior art teach or disclose dust collection.... The present invention is able to collect dust and chips because multiple channels are formed when the plates are pieced together. The smaller the plates, the greater the number of channels per template.

Remarks Accompanying Preliminary Amendment 3 (Aug. 20, 2001).

The claims were thereafter allowed. In explaining the reason for allowance, the examiner stated: "The prior art neither teaches nor suggests a loading device, as claimed, wherein each plate is displaced from adjacent plates by spacing having a width not greater than the smallest dimension of a single particle to be loaded wherein said spacing function [is] to collect dust and partial particles."

When Cat Tech filed its application for the '660 patent, it was preliminarily amended to contain four independent claims, each containing a requirement for spacing having a width "not greater than the smallest dimension of a single particle." The examiner allowed one independent claim, which limited the loading device to a polygonal shape, but rejected the remaining independent claims, stating that the "specification, while being enabling for a loading device having a polygonal shape, does not reasonably provide enablement for any shape." In response, Cat Tech argued:

[T]he claims define the invention based on spacing between adjacent plates and not whether the shape of the plate used to achieve this spacing is, or is not, polygonal.... [T]he present application contemplates this aspect of the invention by stating that "a small inter-plate space is convenient for ease of handling and for accommodating the dust which inevitably develops during the loading work, thus avoiding that the dust is swept into the reactor pipes." Additionally, the specification ... states that "the gap was sufficiently small as not to allow any whole catalyst particles to enter, but allow small chips and broken pieces of catalyst." Moreover, Applicants note that the Examiner has indicated in the reasons for allowance that this spacing is not taught or suggested by the prior art.

Response to Aug. 16, 2004 Patent and Trademark Office Action 7 (Nov. 11, 2004).

Thereafter, the application was allowed. The '660 patent issued on June 14, 2005.

I. TubeMaster's Accused Method

TubeMaster has developed a method of putting catalyst into reactor tubes using loading devices known as Outage Loading Equipment ("OLE'^TM"). TubeMaster has designed four different configurations for its OLE'^TM devices, and has generated AutoCAD® drawings for each of its configurations. While all four...