Moon

Plaintiffs Moon, Wagner, and Subkow, as owners of Letters Patent No. 2,671,537, brought this action for damages and injunctive relief against Cabot Shops, Inc., and Howard Supply Company, claiming infringement of their patent. 1 Defendants denied infringement and affirmatively pleaded that the patent is invalid. The patent is invalid, defendants alleged, because the claims of the patent do not evidence invention over the prior art. As additional reasons for challenging the validity of the patent, defendants alleged that the material elements and combination of elements recited in the claims had been disclosed in prior publications and patents, and were in public use for more than one year pri- or to the filing date of the Moon patent.

The court, after hearing, adjudged the patent valid but not infringed and dismissed the action. Plaintiffs have appealed from that portion of the judgment holding the patent not infringed; defendants have cross-appealed from that portion of the judgment holding the patent to be valid.

The patent in suit involves a portable derrick of the type used for drilling and servicing oil wells. A telescopic derrick is mounted above the driver’s cab at the…