Ransburg Electro-Coating Corp. v. Proctor Electric Company, Inc., and Ionic Electrostatic Corporation

HAYNSWORTH, Circuit Judge.

In this appeal of a patent case, the defendant principally asserts invalidity of the plaintiff’s patents in light of the prior art, file wrapper estoppel against construction of the patent claims so as to cover the accused devices and methods for electrostatic spray painting and of double patenting arising out of the voluntary separation of method and apparatus claims, with the resultant issue of two separate patents, one of which includes method claims, the other of which includes apparatus claims.

After the trial in the Court below, the District Judge prepared and…