In our view of the scope of this claim, infringement must be conceded. Defendant urges that the claim is confined to a device where the first magnet of the series does not have its circuit subjected to the throttle by the operation of a preceding magnet, and that the defendant does not infringe because, in its device, the first one of the rheostat magnets is put under the influence of the throttle by the operation of a preceding magnet. This reasoning is not satisfactory. The language of the claim refers only to the series of rheostat magnets, and it is quite obvious that the first one of this series cannot be affected by the earlier operation of any preceding magnet of the same series. In the defendant's device, the preceding magnet is foreign to this series; but when the critical time comes, when the combination of the Carrichoff patent is to be called upon to operate, it is found, in defendant's device, as in Carrichoff's, that the first magnet of this series has its circuit closed ready to be affected by the closing of the throttle, while the remaining magnets have not, but each, except the first, is put under the influence of the throttle only by the operation of the preceding

one.

Neither do we think that infringement is avoided because the throttle takes only a measured portion of the motor current, instead of the whole, nor because the magnets have a slight, but inoperative, current of electricity passing through them before the throttle operates to pass current enough to make them work.

Much is made of a difference between the form shown in the pater: and the defendant's form as to the relative slow and quick action of the throttle and the magnets. This feature is not found in the claim, unless so far as necessarily implied to make the claim operative, and to that degree, and in the sense involved in that implication, defendant's structure does not eliminate this feature.

We conclude that complainant was entitled to the usual decree on claim 7. Under the circumstances of this case, we see no object in determining the validity or infringement of any other claim involved. We have suggested that claims 5 and 6 may be substantially the same as claim 7; of the remaining seven claims declared upon, some seem to be broader and some narrower than claim 7, and yet this superficial appearance may be incorrect. If counsel think that the validity and infringement of other claims should be decided by us upon this record, we will consider suggestions to that effect filed before the mandate goes down; otherwise, and in view of the fact that complainant, in this court, has planted itself substantially upon claim 7, the decree to be entered below for injunction and accounting, will be based upon this claim alone, and, as to the other nine claims, will declare that no adjudication is necessary in order to dispose of the controversy. If, however, defendant desires to insist that any claim is void (for any other reason than because duplicative), so as to get the benefit of the rule that costs will not be awarded under a patent which is void until disclaimer filed (Cummer v. Atlas [C. C. A. 6] 193 Fed. 993, 998, 113 C. C. A. 611), the remanding will be without prejudice to the right of the court below to consider that matter.

Appellant will recover the costs of this appeal.

MELBER V. SCHOOL DIST, OF PITTSBURGH et al.

(Circuit Court of Appeals, Third Circuit. June 2, 1917.)

1. PATENTS

No. 2217.

82-SUIT FOR INFRINGEMENT DATE OF INVENTION-ESTOPPEL. The acquiescence by the applicant for a patent in the citation against him of references by the examiner precludes him in a subsequent suit from carrying back the date of his invention to antedate such references. [Ed. Note.-For other cases, see Patents, Cent. Dig. §§ 105-107.]

2. PATENTS 328-VALIDITY AND INFRINGEMENT-CONCRETE AND STEEL CON

STRUCTION.

The Melber patent, No. 660,518, for concrete and steel construction, as limited to meet citations by the Patent Office must be confined to a narrow range, and, as so limited, held not infringed.

3. PATENTS 328-VALIDITY-CONCRETE AND STEEL CONSTRUCTION.

The Melber patent, No. 672,175, for concrete and steel construction, claims 8, 9, 10, and 11, relating to wall construction, in view of the prior art, held invalid, as too broad.

Appeal from the District Court of the United States for the Western District of Pennsylvania; Charles P. Orr, Judge.

Suit in equity by Frederick Melber against the School District of Pittsburgh and others. Decree for defendants, and complainant appeals. Affirmed.

Frank H. Drury, of Chicago, Ill., and Edward A. Lawrence, of Pittsburgh, Pa., for appellant.

Kay, Totten & Powell, of Pittsburgh, Pa. (Robert D. Totten, J Rodgers McCreery, and John D. Brown, all of Pittsburgh, Pa., of counsel), for appellees.

Before BUFFINGTON, MCPHERSON, and WOOLLEY, Circuit Judges.

MCPHERSON, Circuit Judge. Letters patent Nos. 660,518 and 672,175 were issued to the plaintiff, Frederick Melber, on October 23, 1900, and April 16, 1901, respectively. The original application covered both patents and was filed August 14, 1899, but the Office called for a division, and this requirement was complied with on May 5, 1900. [1] A few preliminary words may first be said concerning the date of the invention. In order to avoid certain references, an attempt was made to carry Melber's date back to September 14, 1897; but we think the attempt has failed. Without discussing the plaintiff's evidence on this subject, it is sufficient to say that these references were cited against the applicant by the examiner, and that Melber acquiesced in his decision, without any effort to antedate the invention. In our opinion this was a virtual abandonment of the September date, and prevents the patentee from relying on it now. Maier v. Bloom (C. C.) 95 Fed. 159; rule 75, Patent Office.

[2] Both patents are for improvements in cement and steel construction. The specification of No. 660,518, aided by Figs. 1 and 2, will explain its scope:

For other cases see same topic & KEY-NUMBER in all Key-Numbered Digests & Indexes

"My invention, generally speaking, consists in a new and improved construction, in cement, concrete, and like materials reinforced by the introduction of metal bars, whereby the strains consequent of heavy loads are taken up and injury to the construction avoided. I am aware that it is not new to imbed metal in cement or concrete construction to strengthen the same; but such metal has heretofore been imbedded in the cement without any regard to the lines of application of the resultants of the respective strains, thus confusing the calculation of the existing strains and rendering.the accurate application of the formula of engineering impossible. These crude methods of introducing reinforcing metal also result in the requirement of a larger percentage of metal and cement than by the use of my invention. Thus the expense of manufacture is greatly increased; also many strains are thus undiscovered or unmeasured and accordingly unprovided for.

"By the use of my invention the minimum amount of cement and metal is required to produce the maximum amount of strength.

"The following is a detailed description of my invention, reference being had to the accompanying drawings, which make part of this specification: "Figs. 1 and 2 illustrate my method of introducing the reinforcing metal Suppose a construction-such as a girder, slab, or post A, shown in broken elevation to be supporting a load B, applied from above, as indicated by the arrow in the drawings. This, of course, would cause compression strains to appear above the horizontal neutral axis B' B' and tensile strains below the same. I then calculate the tensile strains and the point of application of the resultant D, and through that point I imbed in constructing A a metal rod or bar of sufficient strength to take up and relieve the cement from the calculated resultant of the tension strains. This bar I have indicated by dotted lines in Fig. 1 and marked 1. I may also calculate the resultant of the compression strains D' and imbed through the same rod 1' of sufficient strength to take up said strains; but, as is well known, material such as cement or concrete is able to provide for ordinary compression strains successfully without the aid of reinforcing metal. If I should imbed bar 1 below point D, the point of application of the resultant of compression strains would correspondingly be raised toward the top of the construction A, thus causing an enlargement of the outer fiber strains, the limit of which is, of course, the determined factor of safety, and correspondingly if bar D were raised the point of the application of compression strains will be lowered toward the center of A. By a well-known rule of engineering, as the distance between the two points D and D' decreased, the force applied would correspondingly increase to maintain the 'couple,' so larger metal rods would be required to take up the increased strains. It will thus be seen that the only proper place for the rod 1 to be Imbedded is through the calculated point of application of the resultant of the tension strains-namely, D. The resultant of tension strains, when applied at point D, is of course equal to the sum of the individual tension strains resulting from load B; but if the resultant were applied at any other point than point D an entirely new set of fiber strains would be produced, thus producing fiber strains at the point of the former neutral axis B' B', and hence the formula used for calculating the strains could not be applied, and the strength of the girder would be an unknown quantity. It will be readily seen from the above that the sole point at which the metal must be placed is exactly through the points of application of the resultant of the fiber strains. In such case the exact strength of metal can be determined to take up the known resultant of the tension strains.

"To resist the calculated horizontal shearing strains, I introduce into the construction A the vertical metal rod 2, Fig. 2, with sufficient cross-section to resist the calculated shearing strains. The vertical shearing strains I also take up by introducing a horizontal metal rod 3 of suflicient strength to take up the calculated vertical shearing strains. I also calculate the resultants of the known vertical and horizontal shearing strains, and at right angles to said resultant I imbed a metal bar 44 of sufficient strength to take up the known resultant strains. As these shearing strains are computable exactly, I imbed the rods at the exact point where the strains are exerted, and thus no excess or insufficiency of reinforcement is incurred, as must necessarily be

the case where the metal is introduced without careful calculation as to the exact position it is to be placed.

"It will readily be seen that where I have imbedded my metal rods in the material I have the equivalent of a vertical girder, I being the lower or tension chord, 1a, or, if no rod be there imbedded, the cement representing the compression chord, and the horizontal component of rod 4 would transmit the horizontal shear strains as compression to the top and as tension to the bottom of the construction. By this method I am enabled to design the girder, slab, post, or other construction so as to avoid excess of cement or concrete by calculating the place of application and strength of strains and placing the material properly reinforced just where the load and strains consequent there to demand."

The claims now in controversy are as follows:

"1. In cement or concrete construction, metal reinforcing bars, unattached at their ends to other metal reinforcing bars, imbedded therein transversely to the calculated shearing strains.

"2. In cement or concrete construction, metal reinforcing bars, unattached at their ends to other metal reinforcing bars, imbedded therein transversely to the resultant of the calculated shearing strains.

"3. In cement or concrete construction, metal reinforcing bars, unattached at their ends to other metal reinforcing bars, imbedded therein transversely to the calculated shearing strains, and other metal reinforcing bars imbedded in said construction to resist the tension strains.

"4. In cement or concrete construction, metal reinforcing bars, unattached at their ends to other metal reinforcing bars, imbedded therein transversely to the resultant of the calculated shearing strains, and other metal reinforcing bars imbedded in said construction to resist the tension strains."

7. In cement or concrete construction, metal reinforcing bars, imbedded therein to resist the calculated shearing strains, and other metal reinforcing bars, imbedded in said construction to resist the calculated tension strains, all of said bars being mutually unconnected and two or more of said bars, resisting like strains, having their ends overlapping within the construction."

In their original form, the claims were too broad; e. g.:

"(1) In cement or concrete construction, metal imbedded therein in such a position as to resist the calculated strains."

"(3) In cement or concrete construction, metal bars imbedded therein transversely to the calculated shearing strains."

The examiner rejected these and other claims, citing the patents to Waite, No. 606,696, July, 1898; to De Man, Nos. 607,223 and 607,224, July 12, 1898; to Hennebique, Nos. 611,907 and 611,908, October 3, 1898; and to others. And, as the claims gradually became more limited, he continued to reject them, until they finally took on their present form. As the result of this process, the first four claims are now restricted, instead of fundamental, and must be confined to a narrow range. Claim 7 is even narrower than the first four; it not only requires all the bars to be mutually unconnected, but requires also

that any two or more that resist a like strain shall have their ends overlapping "within the construction." We see no need to pass upon the validity of these five claims, for, without taking time to discuss the evidence, we think it clear that the defendants have not trespassed on the particular domain to which alone these claims can assert an exclusive right. Melber concedes that he was not the first to discover strains in concrete, or to meet them by the use of metal; his criticism of the earlier construction is that the metal had been combined without regard to "lines of application of the resultants of the respective strains, thus confusing the calculations of the existing strains and rendering the accurate application of the formula of engineering impossible,' the result being a wasteful use of metal and cement. He therefore puts much weight on his method of calculating the lines of strain and of locating them accurately, saying:

"It will be readily seen from the above that the sole point at which the metal must be placed is exactly through the points of application of the resultant of the fiber strains."

It is especially to this point that his patent is directed, and obviously his bars can be more readily placed if they are detached than if they are part of a fixed latticelike structure. In the defendants' construction these calculations have not been made, and the bars have not been laid on any such theory. On the contrary, the bars are laid near the surface of the concrete, being merely covered thereby for protection against fire. There are some other differences also that need not be dwelt upon; in our opinion the defendants do not infringe the specified claims of the first patent.

[3] The only claims of the second patent, No. 672,175, that are now insisted on, are Nos. 5, 8, 9, 10, and 11:

"5. In cement or concrete construction, two or more girders, metal rods imbedded in said girder along the lines of the tension strains, other metal rods, unattached at their ends, imbedded in said girders transversely to the shearing strains, and floor slabs connecting said girders."

"8. In cement or concrete construction, a wall of cement or concrete, brackets attached to said wall, and metal reinforcing rods imbedded in said construction.

9. In cement or concrete construction, a wall of cement or concrete, brackets attached to said wall, metal reinforcing rods imbedded in said wall and said brackets, and means for anchoring said construction.

"10. In cement or concrete construction, a wall, brackets attached to said wall, flanges on said wall and said brackets, and means for anchoring said construction.

"11. In cement or concrete construction, a wall, brackets attached to said wall, flanges on said wall and said brackets, means for anchoring said structure, and metal reinforcing rods imbedded in said structure."

The new feature of claim 5 is the "floor slabs connecting said girders"; the other features belonging to the earlier patent. It is not easy to see the importance of the slabs, and so little attention has been paid to this claim in argument that we shall pass it without further comment. The other claims-8, 9, 10, and 11-relate to wall construction and cannot be sustained. In view of the prior art, they are too broad, and were properly declared invalid.

The decree is affirmed.