U.S. Supreme Court KEYSTONE DRILLER CO. v. NORTHWEST ENGINEERING CORP., 294 U.S. 42 (1935)

[Page 294 U.S. 42, 44]

patents were invalid for lack of invention. [Footnote 1] By reason of asserted conflict of decision2 we granted certiorari. [Footnote 3]

[Page 294 U.S. 42, 47]

ability, in view of the prior art, and, in addition, would be contrary to the limitation which the Patent Office file wrapper shows the applicant placed upon his asserted invention.

At the date of filing the application, excavators with pivoted booms, with ditcher sticks pivoted to the booms, with lines attached to the scoop and the ditcher stick, and with sheaves upon the boom and at the upper end of the stick, had been patented, and some had been used. Contrivances of these sorts, in which the same line or cable could be used to elevate the boom and to extend the lower end of the ditcher stick, had been in use and had been patented. [Footnote 4] Prior to Clutter, several excavating machines had embodied the device of attaching a pulley by a link to the top of the ditcher stick of the fixing of a pulley on the end of the stick. [Footnote 5]

[Page 294 U.S. 42, 48]

upon the boom for connecting a pulling member therewith but also for connecting the pulling member with the scoop-carrying member.'

Claims 3 and 4 so phrased were allowed, but the applicant continued, without success, to press other claims not so narrowly limited. [Footnote 6]

We do not attribute the force of an estoppel to what was said by the claimant in seeking to avoid the prior art cited against his broad claims, but we do apply the principle that, where such broad claims are denied and a narrower substituted, the patentee is estopped to read the granted claim as the equivalent of those which were rejected. [Footnote 7] If the claim should be held to comprehend a pulley linked or fixed to the top of the ditcher stick or immovably fastened to the boom, we find such applications in the prior art, upon the basis of which claims worded so broadly as to embrace this method were rejected by the Patent Office and abandoned by the applicant.

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rigidly connected to the lower end of the stick, having a drop bottom to insure accurate discharge of the excavated material, and side rake teeth on the scoop. Only the claims as to the two last-named elements are involved in these cases. It is uncontradicted that prior to Downie's application drop-bottom scoops had been used on out-digging machines. As designed they would probably not have worked upon an indigging machine operated upon Clutter's principle. The question is then, as stated by petitioner's counsel, Was invention involved in taking a known form of out- digging bucket or scoop, rebuilding and applying it to the Clutter in- digging excavator, and making the changes necessary so that it would perform the alleged new functions and results of Downie? We are convinced that the fixation of the scoop to the stick, the pivoting of a drop bottom near the front of the scoop which could be unlatched to drop the contents and closed by checking the momentum of the scoop, and the addition of rake teeth at the sides of the scoop, were all old in the art, and that the combination of them and adaptation of the combined result was a mere aggregation of old elements requiring no more than mechanical skill, and was not, therefore, patentable invention. [Footnote 9]

The judgment are affirmed. Footnotes

Footnote 1 70 F.(2d) 13.

Footnote 2 In Byers Machine Co. v. Keystone Driller Co., 44 F.(2d) 283 (C.C.A. 6) the claims were held valid and infringed. In General Excavator Co. v. Keystone Driller Co., 62 F.(2d) 48; Id., 64 F.(2d) 39, the same court found that the owner of the patents had attempted suppression of evidence of prior use, so as to render more certain the sustaining of the Downie patent which was involved in the Byers Case, and had then used the decree in that case as the basis of application for preliminary injunction in the General Excavator Case. Without passing on the merits, therefore, the court, because of the plaintiff's unclean hands, reversed a decree finding validity and infringement. We affirmed the judgment. 290 U.S. 240, 54 S.Ct. 146. Meantime the Circuit Court of Appeals has permitted reopening of the Byers Case, and the District Court, after considering the proofs as to suppression, has again found the patents valid and infringed. 4 F.Supp. 159, 160. Its decree has been set aside by the Circuit Court of Appeals (71 F.(2d) 1000), but it is not clear whether this action nullifies the finding on the merits. Meantime, also, the District Court which decided the Byers and General Excavator Cases has, in another suit ( against Day & Maddock Company), found validity and infringement, and this cause is now pending on appeal. The petitioner asserts that the original decision of the Circuit Court of Appeals for the Sixth Circuit in the Byers Case has never been set aside so far as concerns the issues of validity and infringement.

Footnote 3 293 U.S. 539, 55 S.Ct. 83, 79 L.Ed. --.

Footnote 4 See the following patents: Rood, 386,438; Cross, 808,345; Benedick, 876,517; Fairbanks, 1,056,268.

Footnote 5 See Benedick, 876,517; Fairbanks, 1,056,268.

Footnote 6 Claims presented and rejected on the prior art embodied such descriptions as: 'Means carried by the boom for connecting the pulling member therewith and with said scoop-carrying member'; 'a pulling member for operating said boom and said scoop-carrying member'; 'pulling means for simultaneously shifting said boom and scoop-carrying member.' They were finally canceled, and effort was abandoned to secure a claim not limited to a pivotal means carried by the boom and connecting the pulling member with the boom and the stick.

Footnote 7 Shepard v. Carrigan, 116 U.S. 593, 597, 6 S.Ct. 493; Crawford v. Heysinger, 123 U.S. 589, 606, 8 S.Ct. 399; Roemer v. Peddie, 132 U.S. 313, 316, 317 S., 10 S.Ct. 98; Royer v. Coupe, , 13 S.Ct. 166; Corbin Cabinet Lock Co. v. Eagle Lock Co., 150 U.S. 38, 14 S.Ct. 28; Hubbell v. United States, 179 U.S. 77, 80, 83 S., 21 S.Ct. 24; I.T.S. Rubber Co. v. Essex Rubber Co., 272 U.S. 429, 443, 47 S.Ct. 136; Smith v. Magic City Kennel Club, 282 U.S. 784, 788, 51 S.Ct. 291.

Footnote 8 See these patents: Williams, 711,449; Benedick, 876,517; Fairbanks, 1,056,268; and Hudson, 1,281,379, granted October 15, 1918, that is, after Clutter and before Wagner.

Footnote 9 See Grinnell Washing Mach. Co. v. E. E. Johnson Co., 247 U.S. 426, 433, 38 S.Ct. 547; Powers-Kennedy Co. v. Concrete Mixing & Conveying Co., 282 U.S. 175, 186, 51 S.Ct. 95.