Federal Circuit Finds New Rationale Constituted New Ground of Rejection on Appeal

A unanimous panel of the Federal Circuit has found that yet another decision by the USPTO Patent Trial and Appeal Board (PTAB) improperly made a new ground of rejection in “affirming” the examiner’s rejections. The court’s decision in In re Biedermann follows similar rulings in Rambus, Stepham, and Leithem, and raises questions as to whether the USPTO’s focus on reducing the appeal and examination backlogs has caused it to lose regard for applicants’ due process rights.

The Application at Issue

The application at issue was Biedermann’s U.S. patent application 10/306,057. As summarized by the court, the claimed subject matter is directed to a bone screw with “an inner thread … that cooperates with the outer thread … of a locking element or screw… to hold [a] rod securely in place.” The threads are “at a 90˚ angle to the central axis … having a substantially rectangular cross-section” that is “sometimes referred to as square threads.” As noted by the court, “[t]he ‘057 Application describes these 90˚-oriented flat threads as advantageously obviating the generation of outward radial forces,” which “avoids splaying of the holding portion’s legs and eliminates the need for an additional element applied to the outside of the legs to avoid splaying,” and “also describes these threads as advantageous because they are easy to produce.”

The Rejections on Appeal

The claims were rejected over U.S. Patent 5.005,562 (Cotrel), U.S. Patent 4,846,614 (“Steinbock”), and U.S. Patent 4,688,832. Cotrel discloses a bone screw with the same general configuration as claimed, while Steinbock “discloses a machining arrangement for moving heavy loads,” with a discussion of “different thread configurations.” Steinbock indicates that square threads are “generally regarded as most efficient” in the context of threads that “are used to repeatedly move or translate machine parts against heavy loads.” Ortloff was cited for teaching another feature of the claims.

The Examiner explained the rejection as follows:

It is noted that there are a limited number of thread profile choices available to a person of ordinary skill in the art for providing a threaded connection. In this regard it is noted that Steinbock teaches different types of threads with a square thread being the most efficient for load transfer (col. 1, lines 14–44).

Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to have provided threads with a square profile on the Cotrel legs, as taught by Steinbock, for efficient load transfer.

(Emphases as added by the Federal Circuit).

The PTAB Decision

In affirming the rejections, the PTAB found:

The fact that Steinbock groups square, Acme, and buttress threadforms would at least suggest their interchangeability. . . . Cotrel already recognized the desirability of eliminating the radial component of the load on screwing and the suitability of a threadform, the saw-tooth or buttress form, that may have typically been used for translational applications to do so. Thus, one of ordinary skill in the art would have a reasonable expectation that a square threadform, which, like the buttress thread is also typically used for axial translation, would function in a manner similar to a saw-tooth or buttress thread to eliminate the radial component of a load on screwing, thereby discouraging spreading of Cotrel’s flanks . . . , or splaying.

Biedermann requested rehearing, arguing that the PTAB had raised a new ground of rejection by changing the rationale behind the rejection. The PTAB denied the request for rehearing, and Biedermann appealed.

The Federal Circuit Decision

The Federal Circuit decision was authored by Judge Linn and joined by Judge Moore and Judge O’Malley. The court framed the issue as follows:

The central question in the present case is whether the Board and the examiner properly relied on the same articulated reasoning and factual underpinnings in rejecting Biedermann’s claims or whether the Board made new findings and adopted different reasons to support a new ground of rejection, thus depriving Biedermann of both notice and an opportunity to respond.

In this regard, “Biedermann argue[d] that the Board did not rely on the examiner’s efficient load transfer rationale … and instead issued a new ground of rejection by adopting a rationale based on newly found facts relating to the avoidance of splaying.” The USPTO argued that “the Board did not issue a new ground of rejection,” but “simply provided a more detailed explanation,” and “respond[ed] to or rel[ied] on Biedermann’s arguments or statements.”

The Federal Circuit saw it this way:

Here, the examiner’s reasoning in support of combining the square thread of Steinbock with the device of Cotrel was that there were a limited number of threads that could be used and that a square thread was the most efficient. …. The Board, on the other hand, found new facts as the basis for concluding that the combination of Cotrel and Steinbock would have been obvious: that Cotrel teaches avoiding splaying with sawtooth threads; that saw-tooth threads are buttress threads; that Steinbock groups together the square threads and buttress threads; and that square threads avoid splaying. The principal reason the examiner combined the references was the efficiency of a square thread. The principal reason the Board affirmed the combination of the references was the avoidance of splaying by using square threads. These are different grounds and form the bases or underpinnings of different rejections.

The court also explained, “A new ground of rejection is not negated by the fact that the Board is responding to an appellant’s argument”

The court noted two other aspects of the PTAB decision that formed a part of the new ground of rejection: its citation of an additional reference that “played an important role … in the Board’s new reasoning” and its discussion of “machinability as another factor” supporting its rationale for combining the references.

Thus, the court vacated the PTAB decision and remanded for further proceedings.

Is the PTAB Learning its Lesson?

The PTAB decisions in this case came nearly a year or more after the Federal Circuit decisions in Stepham, and Leithem, so the PTAB should have had time to study those cases and take care not to enter new grounds of rejection in an “affirmance.” While the PTAB may feel pressured by its backlog to dispose of cases expediently, it cannot overlook its obligations to respect the due process of all applicants when carrying out its obligations to examine patent applications.