(after stating the facts as above). There is no issue here as to the right to use a metal door frame having vertical ribs or flanges extending inwardly from the door jambs. The claims in issue are for metal door frames of such construction, “in combination with a bracing cross-bar of solid construction extending transversely from one jamb of said door frame to the other,” etc., as stated in claim 1, and “in combination with bracing cross-pieces of solid construction extending transversely from one jamb of said frame to the other,” etc., as described in claim 2.

The claims make no reference to the use of the cross-bar or crosspieces in relation to anchorage of the frame to the wall. Claims- 4 and 5, which are not in issue, refer to slots in the cross-pieces adapted to receive the ends of a “hold-fast” in the wall, but even if these claims were in issue, no such alleged infringing structure is here claimed,

The expert testifying for appellant construes claims 1 and 2 as having reference to means for anchoring the door frame into the adjacent wall, and he attaches little importance to the expressions “solid construction” and “bracing” as employed in the claims, stating that the phrase “solid construction” is a curious one, and he could not, in the absence of the file history, state what it means. The same expert says that the specification of the patent throws little light on this language of the claims, and in his opinion the alleged “bracing” action seems to be of very little practical importance.

,But it might be of considerable importance’if the material of the frame itself were not stiff enough to afford the necessary resistance to shocks. Erames may be of thick or of thin material. The specification and drawings of the patent do not indicate what is there contemplated. The thinner the material the greater utility will be found in the bracing action of solid metal cross-pieces. The thicker and stiffer the material of the frames the less necessity would there be for additional bracing. There seems to be nothing complicated or mysterious about this. The language of the claims is such that if there is nothing novel or useful in the “bracing” cross-pieces of “solid construction” the patentee takes nothing by these claims.

[1] The fact that door frames can be made of metal thick and stiff enough to obviate the necessity for the additional bracing afforded *639by metal cross-pieces of solid construction cannot authorize abandonment of the claims in this connection, and a revival of them as an element in some anchoring device, merely because they might also be useful in such a function. The monopoly of the patent is limited in its scope to the claims thereof. White v. Dunbar, 119 U. S. 47, 7 Sup. Ct. 72, 30 L. Ed. 303; Cimiotti, etc., Co. v. Am. Fur Ref. Co., 198 U. S. 399, 25 Sup. Ct. 697, 49 L. Ed. 1100; McClain v. Ortmayer, 141 U. S. 419, 12 Sup. Ct. 76, 35 L. Ed. 800; Harder v. U. S. Piling Co., 160 Fed. 463, 87 C. C. A. 447 (7th Circuit); Wolff Truck Frame Co. v. Am. Steel Foundries, 195 Fed. 940, 115 C. C. A. 628 (7th Circuit).

[2] It is claimed for appellant that any metal, however thin, placed in the frame extending from one side to the other, would have some bracing effect, and would therefore be readable on claims 1 and 2. The file history which is in evidence shows that claims 1 and 2 were originally drawn to cover any iron or steel that might be employed for a cross-piece, but that the claims were not thus broadly allowed. The terms “bracing” and “of solid construction” were afterwards inserted. This was done to avoid conflict with the prior Shean patent, No. 978,948, for wall-tie, granted December 20, 1910. This patent shows a metal door frame, and extending into and adjustably attached to it a corrugated sheet metal piece extending also into the wall, for the purpose of anchoring the frame to the wall. Referring to this invention Buchholz said in a letter to the Commissioner of Patents November 6, 1911, that the Shean construction had no bracing crossbar, and cannot brace the door frame; and as to the words “bracing” and “of solid construction,” which the said letter adopts by way of amendment to the claims, it is stated in the letter, “We have inserted a few words to make the differences more salient,” thus indicating that the inventor differentiated between his solid bracing bar or cross-piece and the corrugated sheet metal of the Shean patent.

The specification of the patent seems to contemplate just such a function of the cross-piece as is stated in claims 1 and 2, wholly independent of the function of anchorage. It is there said:

“Tlie arrangement of parts as described secures a considerable strengthening of the door frame so that any shocks or the like happening against one side are taken up by the other and thus reduced in action, so that the door frame is kept securely in place and position, oven in case of excessive strain.”

If the purpose to be accomplished is, as expressed in these claims and specification, to increase the resisting power of the frame itself as against any shock applied to one side, by communicating the shock through means of the solid bracing piece to the other side, it is manifest that nothing short of a solid piece of metal or its equivalent would do this. It seems clear to us that the structure complained of is an anchor pure and simple. It is not a cross-piece of “solid construction,” nor does it have a “bracing” effect within the purview of-claims 1 and 2 of the patent.

The transverse corrugations of the sheet metal would, in some degree, add to the stiffness of it if pressure were brought against its edges, but we believe that as a resisting agent in a metal door frame *640this would be quite negligible. The purpose and effect of the corrugation was well, and probably truthfully, expressed by witness Men-denhall, who said “it was in order to have a better bond in the mortar joint.”

Being of the opinion that appellee’s device does not infringe claims 1 and 2 of the patent in issue, it will not be necessary to determine whether the Shean patent and the German patent referred to show prior invention by others than Buchholz.

The decree of the District Court dismissing the bill for want of equity is affirmed.