IP Law Daily, PATENT—Fed. Cir.: Hormel Foods defeats patent inventorship ruling on appeal, (May 2, 2023)

By Deirdre Kennedy, J.D.

The contribution of the putative co-inventor was insignificant in quality when measured against the dimension of the full invention.

The federal district court in Wilmington, Delaware, erred in ruling that an individual should be added as a joint inventor of a Hormel Foods Corporation patent directed to methods of precooking bacon and meat pieces, the U.S. Court of Appeals for the Federal Circuit has determined. The specification of the patent, the claims, and the figures provided in the specification all illustrated that the putative co-inventor’s alleged contribution of preheating the bacon or meat pieces with an infrared oven was insignificant when measured against the dimension of the full invention (HIP, Inc. v. Hormel Foods Corporation, May 2, 2023, Lourie, A.).

Hormel Foods Corporation (Hormel) owns U.S. Patent 9,980,498 (the ’498 patent), which is directed to methods of precooking bacon and meat pieces. Specifically, the ’498 patent claims a two-step method that involves a first preheating step using a microwave oven, infrared oven, or hot air, and a second, higher-temperature cooking step. The first step creates a layer of melted fat around the meat pieces, which protects the meat from condensation that may wash away salt and flavor during cooking. The second step prevents the charred, off flavor associated with cooking the meat pieces at higher temperatures.

In early 2005, Hormel embarked on a project to improve on its microwave cooking process for precooked bacon. Then, in July 2007, Hormel planned to meet with David Howard of Unitherm Food Systems, Inc. to discuss the products and processes that Hormel was developing, as well as to discuss Unitherm’s cooking equipment. Appellant’s Unitherm, now HIP, was a company that produced food safety and thermal processing equipment.

Hormel representatives met with Howard in July 2007 and during the subsequent months. The parties eventually entered into a joint agreement to develop an oven to be used in a two-step cooking process. In December 2007, Hormel conducted pork loin testing relating to color development. During this testing, Hormel used both an infrared oven and a more conventional spiral oven. Howard later alleged that it was during these meetings and testing process that he disclosed the infrared preheating concept at issue here.

In January 2008, Hormel conducted additional bacon testing using Unitherm’s mini spiral test oven. After experiencing problems with the spiral oven and testing at Unitherm’s facility, Hormel leased the oven and moved it to its own research and development facility to continue testing. Subsequent testing revealed that turning off internal electrical heating elements in the oven solved the charred, off flavor of the bacon, and preheating the bacon with a microwave oven prevented condensation from washing away the salt and flavor. That testing resulted in a two-step cooking process, the first step involving preheating the bacon and the second step involving cooking the meat in a superheated steam oven. Hormel filed a non-provisional patent application for the two-step cooking process in August 2011, listing Brian J. Srsen, Richard M. Herreid, James E. Mino, and Brian E. Hendrickson as joint inventors. The application issued in May 2018 as the ’498 patent. The four inventors named in the ’498 patent assigned their interests in the patent to Hormel.

In April 2021, HIP sued Hormel in the United States District Court for the District of Delaware, alleging that Howard was either the sole inventor or a joint inventor of the ’498 patent. HIP argued that Howard contributed to at least one of the following: (1) using superheated steam at a level of 90% or more in claims 3 and 12; (2) heating the internal surfaces of the oven to a temperature less than 375º F. in claim 1; (3) preheating by hot air in claim 5; and/or (4) preheating with an infrared oven in claim 5.

After a bench trial, the district court determined that Howard was not the sole inventor of the ’498 patent, but that he was a joint inventor, based solely on his alleged contribution of the infrared preheating in claim 5, which it found to be significant based on the differences between independent claim 1 and independent claim 5. The court ordered the United States Patent and Trademark Office to add David Howard as a joint inventor on the ’498 patent and to issue a Certificate of Correction accordingly.

Hormel appealed.

On appeal, Hormel raised two issues. First, Hormel contended that the district court erred in holding that David Howard is a joint inventor of the ’498 patent because the alleged contribution of preheating with an infrared oven was well known and part of the state of the art and because it was not significant when measured against the scope of the full invention.

Second, Hormel contended that the court erred in holding that HIP met its burden of establishing by clear and convincing evidence that David Howard is a joint inventor of the ’498 patent because Howard’s testimony was insufficiently corroborated.

The court noted that the burden of proving that an individual should have been added as an inventor to an issued patent is a heavy one because the issuance of a patent creates a presumption that the named inventors are the true and only inventors. An alleged joint inventor must prove a claim of joint inventorship by clear and convincing evidence, showing that they made a significant contribution to the invention as claimed.

Pannu test. The parties framed their arguments using the three part test articulated in Pannu, with HIP arguing that David Howard was a joint inventor because he (1) contributed in some significant manner to the conception of the invention; (2) made a contribution to the claimed invention that was not insignificant in quality, when that contribution is measured against the dimension of the full invention; and (3) did more than merely explain to the real inventors well-known concepts and/or the current state of the art.

Hormel challenged the district court’s holding, under the third Pannu factor, that Howard was a joint inventor of the ’498 patent, arguing that the alleged contribution of preheating with an infrared oven was well known and part of the state of the art. Hormel contended that Howard’s alleged contribution to claim 5 (preheating meat pieces with an infrared oven) was disclosed in a prior printed publication, U.S. Patent App. Pub. 2004/0131738 (Holm publication), which, Hormel argued, the court erred in failing to consider. Hormel also contended that the Holm publication was directed to a method and apparatus for browning and cooking food products with steam, expressly providing that one of the cooking sources can be an infrared oven. Hormel pointed to its expert testimony which established that browning is preheating, and thus the Holm publication addressed using an infrared oven to preheat meat pieces three years before Howard’s and Hormel’s 2007 discussions.

Additionally, Hormel argued that the district court failed to analyze the significance of the alleged contribution in light of the full invention (the second Pannu factor) and also erred in its conclusion that the infrared preheating language in claim 5 was significant (the first Pannu factor).

Significance of contributions. Hormel asserted that the court’s findings that Howard was not the sole inventor made it clear that he did not contribute to the overall conception of the claimed method, but at most suggested the use of a piece of equipment. Hormel concluded that this contribution was not significant, and further that there was no indication that infrared preheating solved any specific problem in the field of the ’498 patent. Hormel also pointed out that the specification of the ’498 patent mentions infrared ovens only once, in contrast to microwave ovens, which are mentioned throughout the specification, including in the figures. Hormel finally asserted that the court erred in its claim differentiation analysis between claim 1, which does not include the infrared preheating limitation, and claim 5, which does, because infrared preheating is not what made claim 5 patentable. Hormel concluded that the mere inclusion of the infrared oven language in a claim is not sufficient to label that contribution significant.

HIP, on the other hand, asserted that Hormel was attempting to improperly equate information that is well known in the art with anything in the prior art, however obscure. HIP argued that the Holm publication is obscure, was never commercialized, and had never been described in a marketing or sales brochure or in a textbook. The infrared preheating claim limitation, HIP argued, does not become current state of the art merely because it is mentioned in a single patent publication. HIP also argues that its inventor testimony established that infrared preheating was not the state of the art.

HIP further argued that the district court did not err in determining that Howard’s infrared preheating contribution was not insignificant in view of the whole invention. Nor did the court err in determining that Howard contributed in some significant way to the invention (the first Pannu factor). HIP argued that Hormel improperly attempted to frame the inquiry under the third Pannu factor as one of nonobviousness. HIP also agreed with the district court’s comparison of the claim language in claims 1 and 5 and its determination that the added infrared preheating in claim 5 was significant.

Howard’s contribution was insignificant in quality. The Federal Circuit court agreed with Hormel that Howard was not a joint inventor of the invention claimed in the ’498 patent. The court, in citing the second Pannu factor, noted that an inventor must “make a contribution to the claimed invention that is not insignificant in quality, when that contribution is measured against the dimension of the full invention.” Here, the court found, Howard’s alleged contribution of preheating meat pieces using an infrared oven is “insignificant in quality” to the claimed invention. The concept of preheating with an infrared oven is mentioned only once in the ’498 patent specification as an alternative heating method to a microwave oven, the court noted. Further, the alleged contribution is recited only once in a single claim of the ’498 patent.

The court highlighted the contrast between the insignificant disclosure of preheating with an infrared oven and the prominent featuring of preheating with microwave ovens throughout the specification, claims, and figures. The summary of the invention itself mentions preheating with a microwave oven, but never mentions infrared preheating. Furthermore, the court noted that the examples and corresponding figures employed procedures using preheating with a microwave oven, but not preheating with an infrared oven. In fact, it said, not one example describes preheating with an infrared oven. The figures in the specification further emphasized the centrality of the microwave oven, and the corresponding insignificance of the infrared oven, to the current invention.

Because the specification, claims, and figures all illustrate that Howard’s alleged contribution of preheating the bacon or meat pieces with an infrared oven is “insignificant.

In quality” when “measured against the dimension of the full invention,” the court concluded that Howard was not a joint inventor of the ’498 patent.

Noting that the failure to meet any one Pannu factor is dispositive on the question of inventorship, the Federal Circuit did not address the other factors. The court also did not need to address Hormel’s arguments that the alleged disclosure of infrared preheating in Holm constitutes a well-known concept and/or the state of the art or Hormel’s arguments on whether the district court erred in its conclusion that the infrared preheating language in claim 5 was a significant contribution to the conception or reduction to practice of the invention.

The Case is No. 2022-1696.

Attorneys: Jerry Robin Selinger (Patterson & Sheridan LLP) for HIP Inc. Timothy Michael O’Shea (Fredrikson & Byron, PA) for Hormel Foods Corporation.

Companies: HIP Inc.; Hormel Foods Corporation

Cases: Patent FedCirNews DelawareNews GCNNews