Conveyor Belt Fastener Design Held Not Eligible for Trade Dress Protection

Intellectual Property Law

In Flexible Steel Lacing Co. v. Conveyor Accessories Inc.,1 the Seventh Circuit Court of Appeals ruled that a conveyor belt fastener’s “beveled center scallop” design was not entitled to trade dress protection because it was utilitarian.

Flexible Steel Lacing Co. (Flexco) and Conveyor Accessories Inc. (CAI) were competitors in the belt conveyor industry. Belt conveyors are used in a wide variety of material handling applications, ranging from transporting coal from a mine shaft to moving groceries at the checkout lane. Many belt conveyor systems employ an endless flexible rubber belt comprised of multiple high-strength rubber belt segments that are spliced together, and mechanical belt fasteners can be used to splice the segments together.

In 1999, Flexco introduced the Scalloped Edge fastener, a mechanical belt fastener featuring leading edges that are scalloped. “Compared to a straight-edged fastener, the Scalloped Edge fastener displaces and compresses less rubber when it is installed because less plate material is being imbedded in the belt,” the court said.

Flexco received utility and design patents for the fastener. After the patents expired, Flexco applied for and received federal trade dress protection for the fastener’s beveled center scallop. Flexco’s U.S. Trademark Registration No. 4,971,326 (Flexco’s registered trade dress, or the beveled center scallop) claimed only the beveled concave curve of the leading edge, as indicated by the darkened outline border in the illustration below:

Flexco sued CAI for trade dress infringement based on fasteners that Flexco said were confusingly similar to its trade dress. CAI argued the design was not eligible for trade dress protection because it was functional. The district court agreed with CAI, and the Seventh Circuit affirmed.

If a product’s functional feature were permitted to be used as a trademark, competition would be unduly stifled because a trademark can be “renewed in perpetuity,” the Seventh Circuit observed. Five factors are generally considered in the determination of whether a design is functional:

(1) the existence of a utility patent, expired or unexpired, that involves or describes the functionality of an item’s design element; (2) the utilitarian properties of the item’s unpatented design elements; (3) advertising of the item that touts the utilitarian advantages of the item’s design elements; (4) the dearth of, or difficulty in creating, alternative designs for the item’s purpose; and (5) the effect of the design feature on an item’s quality or cost.

The court rejected Flexco’s argument that the utility patent referred solely to the two convex curves of the fastener’s leading edge as utilitarian features that improved the fastener’s bite and profile, finding it was “simply not supported by the plain language” of the relevant patent claim. The court also disagreed with Flexco’s argument that the center scallop was not a functional element of the utility patent. There was “clear language in the utility patent disclosing the utilitarian advantages” of the scallop, the court reasoned.

“The utility patent clearly discloses that the beveled center scallop improves the bite and reduces the profile of the fastener’s leading edge,” the court explained. “This is functional because consumers would pay to have it rather than be indifferent toward or pay to avoid it.” The court also indicated that the utility patent’s strong evidence of functionality was bolstered by Flexco’s own advertisements, internal communications and statements to the U.S. Patent Office. The court said Flexco’s marketing brochures “emphasize the utilitarian advantages of the beveled center scallop” and that Flexco stated during patent prosecution that the scallop “reduces the exposure to cleaner blades, skirt rubber, and return idlers” and “reduces the effects of impact between the fasteners and belt cleaners.”

The court also rejected Flexco’s argument that the scalloped design was not functional because CAI did not show that the scallop’s utilitarian properties could not be attained via other designs. After CAI put forth evidence of the utility patent, the “heavy burden” shifted to Flexco to show that the scallop was not functional. “Where functionality is established, there is no need to consider alternative design possibilities,” the court said.2 Accordingly, the court held the following:

Here, . . . there well may be numerous alternative designs for the space between the two convex curves of the metal fastener. But because Flexco has claimed the beveled center scallop as a solution to a problem in its patents, in its statements to the [U.S. Patent Office], and in its advertisements, the beveled center scallop properly remains in the world of patents.

Consequently, the court held that Flexco’s registered trade dress was functional and therefore invalid as a trademark.


There are significant limits to trade dress protection particularly. Here, Flexco appears to have done the most it could to protect the functional features of its intellectual property. Once utility and design patents expire, however, the success of attempts to protect functional aspects of inventions becomes severely limited, reflecting the fact that the Constitution secures for inventors the rights to their discoveries only for “limited times.” In the words of Socrates, “The secret of change is to focus all of your energy, not on fighting the old but on building the new.”

1 Flexible Steel Lacing Co. v. Conveyor Accessories Inc., 955 F.3d 632, 2020 USPQ2d 10298 (7th Cir. 2020).

2 Id., 955 F.3d at 650 (citing TrafFix Devices, Inc. v. Mktg. Displays, Inc., 532 U.S. 23, 33, 58 USPQ2d 1001, 1007 (2001); Specialized Seating Inc. v. Greenwich Indus. L.P., 616 F.3d 722, 726-27, 96 USPQ2d 1580, 1583-84 (7th Cir. 2010) (stating that “claims in an expired utility

Irah Donner is a partner in Manatt’s intellectual property practice and is the author of Patent Prosecution: Law, Practice, and Procedure, Eleventh Edition, and Constructing and Deconstructing Patents, Second Edition, both published by Bloomberg Law.


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