Fernandez

Appellees are co-owners, in trust, of Day reissue patent number 18,755. They brought this action in the District Court for infringement of claims 3, 4, 5 and 6 thereof, and the court, holding the patent valid and infringed, gayp its interlocutory decree enjoining further infringement and ordering an accounting. On this appeal from that decree both validity and infringement of the patent are in issue.

The patent in suit is for a means of precooling railway refrigerator cars. The standard refrigerator car is cooled by ice contained in the ice bunkers at either end of the car. The ice bunkers are separated from the balance of the car by bulkheads. Air may circulate between each ice bunker and the body of the car by means of openings extending across the bulkhead, one at the top of the bulkhead and the other at the bottom of the bulkhead which rests upon a slatted false floor extending the length of the car. Circulation of the air is normally produced by convection, the air moving downward through the ice bunkers as it is cooled by the ice, and upward in the body of the car as it absorbs heat from the contents of the car. This convection circulation is sufficient to maintain an…