No-Joint Concrete Pipe Co., a Corporation v. R. A. Hanson, an Individual, R. A. Hanson Co., Inc., a Corporation

Appellant has brought this suit for infringement of patent. Appellees defended upon the grounds, first, that appellant’s patent was invalid for lack of invention, and, second, that there was no infringement. The District Court for the Eastern District of Washington, Northern Division, held the patent to be valid but not infringed. Appellees challenge the first holding. Appellant appeals from the second.

The device in question is for the forming of concrete pipe in place for use in irrigation and drainage systems. By means of the device pipe is formed by the following method: A ditch is dug, conforming to the outer dimensions of the pipe. Concrete is fed into the ditch around an inner core or form which is removed after the concrete has set. This method, in general, is not new in the art. What is new is the fact that the device permits a continuous operation. New pipe is continuously poured while the already formed pipe, is still hardening. Thus it is not necessary to permit one section of the pipe to harden before passing on to the pouring of a new section. Also, the top, bottom and sides of the pipe are formed simultaneously. This is accomplished by pouring concrete through a…