■devices in figure 9 of the patent drawings, the pipe supports used during installation are not a detail of the claimed invention. The Goff claims in suit define an installed system rather than a ■method of installation or the supplemental structures used to aid in making the installation. We believe that the defendant’s use of spaced concrete blocks to •support the pipe during the installation •does not warrant a conclusion that such blocks are the only support for the pipes .after the insulating concrete has set and •does not provide a sufficient distinction from the Goff patent to avoid infringement.
In determining whether an ac•cused installation infringes a valid patent, resort must be had in the first instance to the words of the claims. If the accused matter falls clearly within the claim, infringement is made out and that is the end of it. Graver Tank & Mfg. Co. v. Linde Air Products Co., 1950, 339 U.S. 605, 607, 70 S.Ct. 854, 94 L.Ed. 1097.
Patent specifications and drawings are not to be read so as to limit the scope of the claim recital where the claim recital is clear and unambiguous. While claims should be construed in the light of the specifications and drawings to obtain an understanding thereof, the illustrative embodiments specified are not to be read into the claims. See
White v. Dunbar, 1886, 119 U.S. 47, 51-52, 7 S.Ct. 72, 30 L.Ed. 303. The claims alone define what is covered by the patent. See Kuhne Identification Systems, Inc. v. United States, 1936, 82 Ct.Cl. 237, 258.
We note that the contract under which •the accused installation was made at Mc■Guire Air Force Base specified that the ■underground conduit be formed of a mixture consisting of Portland cement, .aggregate, admix and water in proportions substantially identical with the proportions taught by the specification of the Goff patent. The contract specified that the insulating concrete have a density of approximately 23 pounds per cubic Toot. Claim 2 of the Goff patent recites ■that the insulating concrete weighs approximately 23 pounds per cubic foot. There is no question that the accused installation infringes upon the claims in the Goff patent. However, in those portions of the accused installation where a structural concrete encasement or preformed vermiculite planks were used to enclose the heat-insulating concrete, there was no infringement of the Goff patent invention.
We conclude and held, therefore, that claims 1, 2, 3, 5, 6, and 7 of Goff patent No. 2,355,966 are valid and have been infringed by the accused underground pipe system installed at defendant’s McGuire Air Force Base, and judgment will be entered to that effect.
The extent of liability will be determined in further proceedings before the Commissioner.
It is so ordered.
JONES, Chief Judge, and WHITAKER and LITTLETON, Judges, concur.
MADDEN, Judge
(dissenting).
I think the Government’s structure did not infringe the plaintiff’s patent. The essence of the plaintiff’s discovery is that cell-concrete, though necessarily weaker than ordinary structural concrete, may, if mixed in the right proportions be light enough to be a good insulating material, but heavy enough to bear the weight of the pipe without being crushed by that weight. The plaintiff’s discovery thus makes it possible to eliminate the metal roller or rocker supports for the pipe which were thought to be necessary when the pipes were surrounded by a light substance such as mineral wool or cell-concrete.
The court’s opinion says that there was skepticism in the trade as to whether the plaintiff’s discovery was practicable, i. e., whether if the cell-concrete was really made light enough to make good insulation, it would bear the weight of the pipes without crushing. If the Government’s installation operates satisfactorily for 100 years, it will still prove