Macon Concrete Roller Co. v. Brooks-Callaway Co.

272 F. 341, 1921 U.S. Dist. LEXIS 1343
CourtDistrict Court, N.D. Georgia
DecidedMarch 2, 1921
DocketNo. 141
StatusPublished
Cited by1 cases

This text of 272 F. 341 (Macon Concrete Roller Co. v. Brooks-Callaway Co.) is published on Counsel Stack Legal Research, covering District Court, N.D. Georgia primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Macon Concrete Roller Co. v. Brooks-Callaway Co., 272 F. 341, 1921 U.S. Dist. LEXIS 1343 (N.D. Ga. 1921).

Opinion

SIBDEY, District Judge.

The infringement insisted upon is of claims 5 and 6 of patent No. 1,273,022, granted July 16, 1918, to Ash-more and Morgan, for a device and process for finishing concrete pavements by rolling same when fresh and plastic with a roller of small diameter and relatively great length and light weight, so as to be adapted to float on the semifluid concrete and smooth the same and eliminate excess water. Infringement is also alleged of claims 1, 2, and 3 of patent No. 1,302,275, granted the same persons on April 29, 1919, for a roller to finish pavement between the rails of a railroad track by a roller rolling upon the rails, and finishing the concrete surface, and grooving the same next to the rails. By the evidence and concessions made on the hearing, utility is not disputed, and the use of an infringing device is admitted, and the case turns upon the validity of the patents.

[1] A roller as an instrument and rolling as a method of smoothing and consolidating a soft surface are age-old. They were used upon concrete many years before the granting of the patents in question. First impressions are against the patentability; there seeming but a modification in degree of the old idea and instrument, such as mechanical skill in the art would suggest. Such was the first impression in the Patent Office. The former art in concrete, as other matters, depended for efficacy upon the weight of the roller. If there were inequalities in the surface, the roller, mounting them, imposed a larger part of its weight upon them, and compressed them until they were even with the general surface, which, with the ensuing more general distribution of the weight, would then support the roller. Repeated passage over the surface compressed and smoothed it. The greater the weight, the more efficient the roller. But a weighty roller could not be used upon a very soft surface, because it would simply mire into it, and, if the material rolled had surplus water in it, the rolling would only make the material more plastic and unreliable. So in the art of laying concrete pavement only the very stiff concrete was consolidated by rolling Jn this sense, and it was afterwards finished by an added unrolled coat of mortar.

[343]*343A great economy in the work was then found in using a much, more plastic concrete, and such is alone now used in pavement work; the finishing coat of mortar being also omitted. But this more economical form of concrete carried its disadvantages. The former heavy consolidating rollers were abandoned as unusable and ceased to have any place in the practical art. This concrete, like other, when first laid, was full of air-filled crevices, and unlike the dry concrete had much excess water also included. This, when absorbed or dried out, left the mixture porous and weakened physically, if not damaged chemically. Tamping as a means of solidifying and expelling the water and air was, like the heavy roller, not very effectual, because, while it would drive the solid portions of the mixture together and cause the air and water to rise from it, it did not remove the water, or smooth or straighten the surface of the concrete, and was expensive. It also would leave masses of the coarse aggregates nearer the surface at some points than others, with the result that they would protrude and drag, -when the surface was leveled with a strike board, and their having less shrinkage than other parts of the mixture would make high places in the pavement when dried. Hand floats were used to smooth the surface and bring up the excess water in the surface coat; but this did not remove the water, but allowed it to a great extent to sink back, and the operation itself was difficult on a wide pavement, laborious, and expensive.

Nevertheless wet concrete had established itself as the material for pavements in the face of the difficulties stated. Now, concrete is but a mass of stones, the crevices between which are filled with sand, itself a mass of irregularly shaped solids, whose crevices in turn are filled and- united by fine cement and water, making “mortar." If the larger solids are brought closer together, the intervening crevices are decreased, and the included sand, cement, water, and air are forced out. If, in turn, the grains of sand are themselves brought nearer together, the included cement and water and air will he forced from it, and, being lighter, will tend to rise to the surface. The nearer approach to each other of these solid masses may be compelled by pressure, as in the use of the heavy roller, or by a blow, as in the case of tampinc, where conditions permit. If the solid masses were perfect spheres, like a peck of bullets, the only way to accomplish this would be by crushing or deforming them. But they are irregularly shaped, and as jumbled together indiscriminately may not be at all well packed. But as they partly float in a semifluid mixture, with the assistance of gravity alone, they may be made to pack themselves by agitation. Thus, if a bucket of mortar he set aside for some minutes, water will rise to the surface, and the sand becomes stiff and consolidated. If it be rolled in a wheelbarrow over_a pavement for a less time, the amount of water raised and the consolidation of the sand will he much greater.

The conception that a roller, which in the late development of the concrete art had been abandoned because its weight made it unusable, might be used for every beneficial purpose, if, instead of its weight, its relative lightness were depended on, and consolidation attained more by the gravity of the rolled material than by that of the roller, in [344]*344my judgment was invention. The conception was new. The practical contractor to whom it was first presented very emphatically expressed his contempt of it. The Examiner of Patents, in his first letter of May 2, 1916, rejecting the claims, said:

“Tiie action of the roller is believed to be inconsistent with the applicant’s insistence upon the lightness of the roller.”

Only by the exhibition of numerous testimonials to the actual performance of the method and device was approval secured. The fact is indisputably established that a very great and sudden improvement in the art has followed the use of this idea, an advance resulting, not only in economy of operation, but excellence of product. The insistence of the patent upon “a small diameter and a comparatively great length,” securing thereby a long bearing surface with light weight, is vital to this, bufa reversal of the old heavy roller, where short bearing surface and great weight were sought. So the detail of “comparatively light weight adapted to float on soft, plastic concrete” is expressive of the fundamental idea of this invention, but a reversal of all previous notions of rollers, by which a floating roller would be a foolish paradox and a contradiction in terms. Noting the action of this new “roller” when it passes first over the rough, but soft, mass, in riding upon the high places, it acts as an ordinary roller in pushing them down to a general level, the softness of the mass permitting this, in spite of the light weight of the roller. Additional weight may be given it, if occasionally necessary, by bearing on the handle. Its great length insures that the level established is the general level of the work.

This action on the soft concrete soon causes much air and water and mortar to rise, making a fluid coating over the work.

Free access — add to your briefcase to read the full text and ask questions with AI

Related

Brooks-Callaway Co. v. Macon Concrete Roller Co.
279 F. 114 (Fifth Circuit, 1922)

Cite This Page — Counsel Stack

Bluebook (online)
272 F. 341, 1921 U.S. Dist. LEXIS 1343, Counsel Stack Legal Research, https://law.counselstack.com/opinion/macon-concrete-roller-co-v-brooks-callaway-co-gand-1921.