Federal Circuit Vacates PTAB Win for Seed Drill Patent: Drawings Count as Evidence
Photo: RDNE Stock project / Pexels
A drawing in an old patent can be enough to show what the prior art disclosed, even when the written text says nothing about the feature. The US Court of Appeals for the Federal Circuit applied that principle on 30 October 2026 when it vacated a Patent Trial and Appeal Board (PTAB) decision that had upheld an agricultural patent owned by Italian machinery maker Maschio Gaspardo.
The patent and the challenge
Maschio Gaspardo's US Patent 8,770,121 covers a seed distribution element for precision pneumatic seed drills, machines that use air pressure to hold seeds on a rotating sowing disc and drop them one at a time along a row. The claims require a seal on a movable part of the housing and a "thrust-bearing element", supported so that it can rotate in that movable part, to absorb some of the axial load the disc puts on the seal.
After Maschio Gaspardo sued Precision Planting for infringement, Precision Planting petitioned for inter partes review (IPR). The PTAB held all challenged claims not unpatentable. Precision Planting appealed only one ground, which combined an operator's manual for planters, a European patent publication referred to as Fiorido, another US patent and prior art admitted in the patent itself.
The dispute: does Fiorido show a thrust bearing?
The case turned on whether Fiorido's driving disk touches its sowing disk. Both sides' experts agreed that if it did, a skilled person would understand the driving disk to carry some axial load, which would make it a thrust-bearing element.
The Board found that Fiorido did not teach this, for three reasons. The text never says the two disks are in contact. The drawing also shows a seal touching the disk, so the seal might take all the load. And the patent owner's expert doubted that the drawing should be read literally.
Chief Judge Moore, writing for the panel, held that none of these reasons amounted to substantial evidence:
- Silent text does not cancel a clear drawing. Contact may not be needed for the purpose Fiorido describes, but that does not negate contact that Figure 2 plainly shows. Older case law confirms that patent drawings can be decisive, even for features the text does not explain.
- The seal is irrelevant. Contact between the seal and the disk does nothing to disprove contact between the driving disk and the disk.
- Expert testimony against the record. The expert gave a reason to doubt a different contact point in the figure, but none for this one. An alternative embodiment in which the driving disk bears no load cannot override the embodiment shown. Expert testimony plainly inconsistent with the record must be disregarded.
The court therefore vacated the decision on the disputed claims (claims 1 to 3, 7 to 12 and 16) and sent the case back. It did not decide Precision Planting's separate arguments about motivation to combine the references, which the Board will now look at again.
Practical points
- Read the figures. In both prosecution and IPRs, drawings in prior art can disclose features the text never mentions.
- Experts must engage with the figure. Testimony that asks a tribunal to ignore what a drawing clearly shows, without a specific technical reason, carries little weight on appeal.
- Not the end of the patent. A vacatur and remand means a new decision, not automatic cancellation. The Board must still decide whether the claims would have been obvious.
The opinion is nonprecedential.
Sources
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