The claim may be divided as follows: A sheet metal elbow having (a) a lapped joint at its inner or throat side; (b) corrugations which extend without break, circumferentially around the elbow at the outer curve thereof, and which are pressed against each other at the inner or throat side of the elbow; and—as a result—-(c) the fact that the two thicknesses of the lapped joint are thereby clamped close together, while the elbow remains composed of a single thickness of corrugated metal at the outer side.

The prior art shows that a sheet metal elbow having a lapped joint is not new, and that a lapped joint, at the inner or throat side of the elbow, is not new. The novelty of appellants’ device, then, if it have any, consists in the specific way the lapped joint is fastened or held, viz.: by the corrugations being pressed together at the inner or throat side of the elbow.

Corrugations, extending without break circumferentially around the elbow at the outer curve, were not new. Such corrugations appear in the Eawrence elbow, patent No. 485,124; also in the second Deickmann elbow, patent No. 500,119. In each of these elbows the corrugations are pressed together at the inner or throat side of the elbow. In the Kemp patent, however, after the coi'rugations are made, the corrugated part of the pipe is pressed in the axial direction of the pipe, where by the corrugations are brought closely together, and the lapped parts, along the joint, are secured together. This is done before the bending takes places, so that when the pipe is finally bent, the compression on the inner side of the elbow is not changed, the elbow being obtained by spreading or distending the corrugations on the outer side. It is not shown that this process is pursued in the making of the elbows of the prior árt; and it is on this specific method or process of making the elbow, that the chief claim of novelty is predicated.

It is to be noted, however, that these elbows are intended to carry off smoke; and that smoke, under draft, unlike gas or other substances acting under pressure, will carry, without leakage, through a pipe that is loosely jointed. There is no functional purpose, therefore, in the closeness of the compression obtained. The functional purpose aimed at is, not imperviousness, but strength.

Keeping this in mind, we cannot escape the conclusion that, except possibly the process, Kemp has disclosed nothing really useful that was not known before. He lays no claim to a process patent; nor does appellee follow his process. The appellee’s elbow is manufactured by a machine that, instead of in one act compressing the corrugations axially, as Kemp does, crimps or corrugates the elbow, serially—corrugation' upon corrugation—until the elbow is completed. True the articlé, as an article, is perhaps nearly the same as Kemp’s. The same kind of close contact of corrugations *403is obtained. But Kemp has not obtained a patent on the process; nor does appellee employ the process; and Kemp has no patent on the mere closeness of the corrugations. So in any view that can be taken, Kemp has no right to prevent appellee from manufacturing and selling the article.

The decree of the Circuit Court will be

Affirmed.