In Hip, Inc. v. Hormel Foods Corp.,¹ the U.S. Court of Appeals, Federal Circuit, held that there was no joint inventorship when the contribution of preheating meat pieces using an infrared oven was insignificant in quality because it was mentioned only once in the patent specification as an alternative heating method to a microwave oven and was recited only once as part of a Markush group in a claim. The court ruled that the use of infrared heating appeared to be an afterthought in the creation of the main claimed invention, which was a two-step precooking method. The court also noted that it would seem to be absurd for joint inventorship and ownership to be held by an equipment manufacturer when significant discoveries and refinements of the cooking procedure were made without the manufacturer present.

Hormel Foods Corp. owned U.S. Patent 9,980,498 (the ’498 patent), relating to methods of precooking bacon and meat samples. The ’498 patent claimed a two-step method, including a first preheating step employing a microwave oven, infrared oven or hot air, and a second higher-temperature cooking step. The first step produced a coating of melted fat around the meat samples that prevented condensation from the meat that could remove salt and flavor during cooking.²

The ’498 patent included three independent claims, claims 1, 5 and 13. Claims 1 and 5 recited the following:

1. A method of making precooked bacon pieces using a hybrid cooking system, comprising:

preheating bacon pieces with a microwave oven to a temperature of 140º F. to 210º F. to create preheated bacon pieces, the preheating forming a barrier with melted fat around the preheated bacon pieces and reducing an amount of condensation that forms on the preheated bacon pieces when transferred to a cooking compartment of an oven, the barrier preventing any condensation that forms from contacting the preheated bacon pieces under the melted fat and diluting flavor in the preheated bacon pieces;

transferring the preheated bacon pieces to the cooking compartment of the oven, the cooking compartment heated with steam from an external steam generator, the external steam generator being external to the cooking compartment, the steam being injected into the cooking compartment and being approximately 400º F. to 1000º F. when the steam leaves the external steam generator, the cooking compartment including internal surfaces, the steam assisting in keeping the internal surfaces at a temperature below 375 ºF. thereby reducing off flavors during cooking in the cooking compartment; and

cooking the preheated bacon pieces in the cooking compartment to a water activity level of 0.92 or less to create precooked bacon pieces.³

5. A method of making precooked meat pieces using a hybrid cooking system, comprising:

preheating meat pieces in a first cooking compartment using a preheating method selected from the group consisting of a microwave oven, an infrared oven, and hot air to a temperature of at least 140º F. to create preheated meat pieces, the preheating forming a barrier with melted fat around the preheated meat pieces and reducing an amount of condensation that forms on the preheated meat pieces when transferred to a second cooking compartment, the barrier preventing any condensation that forms from contacting the preheated meat pieces under the melted fat and diluting flavor in the preheated meat pieces;

transferring the preheated meat pieces to the second cooking compartment, the second cooking compartment heated with an external heating source, the external heating source being external to the second cooking compartment, the second cooking compartment including internal surfaces, the external heating source assisting in keeping the internal surfaces at a temperature below a smoke point of fat from the meat pieces thereby reducing off flavors during cooking in the second compartment; and

cooking the preheated meat pieces in the second cooking compartment to a water activity level of 0.92 or less to create precooked meat pieces.⁴

In 2005, Hormel initiated a plan to improve its microwave cooking process for precooked bacon. In 2007, Hormel arranged to meet with David Howard of Unitherm Food Systems, Inc., now HIP, to review the cooking equipment and methods that Hormel was working on as well as to review Unitherm’s cooking equipment. Hormel performed pork loin testing relating to color development, which used both an infrared oven and a more typical spiral oven. Howard claimed that during meetings and the testing process he divulged the infrared preheating idea.⁵

After encountering difficulties with the spiral oven and testing at Unitherm’s facility, Hormel rented the oven and moved it to its own location for further testing. The additional testing disclosed that switching off the interior electrical heating components in the oven resolved the burned, inedible flavor of the bacon, and preheating the bacon with a microwave oven avoided condensation from removing the salt and flavor. The additional testing was the basis of the inventive two-step cooking process, with the first step preheating the bacon and the second step heating the bacon in a superheated steam oven. Hormel filed a non-provisional patent application for the two-step cooking process, identifying Brian J. Srsen, Richard M. Herreid, James E. Mino and Brian E. Hendrickson as co-inventors, all of whom assigned their interest in the invention to Hormel. The non-provisional patent application was granted as the ’498 patent.

HIP sued Hormel, asserting that Howard was either the only inventor or a co-inventor of the ’498 patent. HIP contended that Howard invented 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 5.⁶

The district court decided that Howard, by providing a contribution to the preheating with the infrared oven idea in independent claim 5, was a joint inventor of the ’498 patent. The court ordered the United States Patent and Trademark Office to include Howard as a coinventor on the ’498 patent and to issue a Certificate of Correction to publish Howard’s coinventor status.

Hormel appealed, and the Federal Circuit reversed. On appeal, Hormel argued that the district court incorrectly held that Howard was a joint inventor of the ’498 patent because the asserted contribution of preheating with an infrared oven was public knowledge and was not substantial when compared to the entire invention.

The court initially explained that to be considered a joint inventor, a person must make a substantial contribution to the claimed invention. HIP contended that 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 is 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.⁷

Hormel countered that the district court did not evaluate the importance of the asserted contribution in view of the complete invention and also incorrectly held that the infrared preheating feature in claim 5 was important. Hormel also argued that simply incorporating the infrared oven language in claim 5 was not enough for the contribution to be considered significant.

The Federal Circuit agreed with Hormel that Howard was not a joint inventor because Howard’s asserted contribution of preheating meat pieces using an infrared oven was insignificant in quality when compared to the claimed invention. The court reasoned that Howard’s contribution of preheating using an infrared oven was indicated only once in the ’498 patent specification as a substitute heating method to a microwave oven and was recited only once in a single claim in a Markush group consisting of a microwave oven, an infrared oven and hot air in the ’498 patent.  

Instead of the insignificant description of preheating using an infrared oven, preheating using a microwave oven was discussed significantly throughout the specification, claims and figures. Specifically, the disclosed examples and relevant figures used procedures employing preheating with a microwave oven, not preheating with an infrared oven. The drawings also highlighted the significance of the microwave oven and the unimportance of the infrared oven. Therefore, the Federal Circuit held:

In summary, 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,” … which squarely focuses on a preheating step using a microwave oven. Thus, we conclude that Howard is not a joint inventor of the ’498 patent.⁸

The court noted that the other Pannu factors need not be considered because the failure to satisfy any single Pannu factor was dispositive regarding the determination of inventorship.

Takeaways

In evaluating the second Pannu factor, the Federal Circuit held that the use of an infrared oven to preheat the meat pieces was insignificant because it was stated only once in the specification as an alternative heating method and was recited in a Markush group as an alternative to other preheating methods. The court remarked that it would be “absurd” to allow joint ownership by a manufacturer when the significant discoveries and refinements of the methods were made in a research facility separate from the manufacturer.

The HIP v. Hormel decision emphasizes the importance of drafting the specification and claims properly in the first instance when deciding individuals to include as joint inventors. Thus, this case is a lesson for individuals working with others on a potentially patentable project that it is important to make sure significant contributions to the conception of the claimed invention are thoroughly described in the specification and recited in the claims when considering the overall claimed invention features to be considered eligible as a joint inventor.

The court was also clear that to be a joint inventor, the individual must satisfy all three Pannu factors, and failure to satisfy even just one of the factors will disqualify the individual from being considered a joint inventor. That is, to be a joint inventor, the individual must have:

1. contributed in some significant manner to the conception of the claimed invention;
2. made a contribution to the claimed invention that is not insignificant in quality when that contribution is measured against the dimension of the full invention; and
3. done more than merely explain to the real inventors well-known concepts and/or the current state of the art.

¹ Hip, Inc. v. Hormel Foods Corp., 66 F.4th 1346, 2023 USPQ2d 521, 2023 WL 3184358 (Fed. Cir. 2023).

² Id., 66 F.4th at 1348.

³ Id., 66 F.4th at 1348.

⁴ Id., 66 F.4th at 1348.

⁵ Id., 66 F.4th at 1349.

⁶ Id., 66 F.4th at 1349.

⁷ Id., 66 F.4th at 1350 (citing Fina Oil & Chem. Co. v. Ewen, 123 F.3d 1466, 1473, 43 USPQ2d 1935 (Fed. Cir. 1997)).

⁸ Id., 66 F.4th at 1352–53 (quotation marks omitted).