61 F. 840 | S.D.N.Y. | 1894
This bill in equity is founded upon the alleged infringement of letters patent No. 293,740, dated February 19, 1884, to Isaiah Smith Hyatt, for an improvement in the art of filtering water. The title to the patent has become vested in the complainant. At and prior to the date of the invention, the patentee was connected with a corporation which was endeavoring to introduce to the public filters having a filter bed of sand for the filtration of turbid water, or water which contained suspended impurities. The apparatus was not a success, by reason of its imperfect purification of the water, and the patentee, in his search for an improvement, found a -remedy which is the subject of the patent in suit, and the use of which is not limited to any particular mechanical apparatus. The patentee, in his specification, described his invention as follows:
“The invention relates to improvements in the art of filtration; and it consists in the method hereinafter described of arresting and removing the particles of foreign matter liable to pass through the filter bed with the escaping water during an uninterrupted process of filtration, or one in which a stream of water is passed through a bed of filtering material contained in a filter, the filter being a receptacle containing a bed of filtering material, and-having a supply pipe for the introduction of the water and a pipe for its passage therefrom, the said supply pipe having another pipe, through which I in*841 troduce into the water, simultaneously with its passage into the filter, a substance—such as perehloride or persulphate of iron—for the purpose* of sufficiently coagulating the impurities in the water to admit of their arrest by the bed during the passage of the water through the filter. In practicing the invention, some form of mechanical apparatus must be employed; and, while I do not confine myself to any particular construction, I recommend the apparatus described and claimed in letters patent of the United States No. 273,-542, granted to 3ohn W. ITyatt on the Oth day of March, 1883, which 1 have used with very satisfactory results.”
It further appears from the specification that the particular apparatus which the patentee recommended to he used with his invention consisted, in general, of an upper and lower compartment, separated by a. diaphragm. The lower compartment was provided with a supply pipe and a bed of sand, or other suitable filtering agent. The specification proceeds as follows:
“The supply pipe,-If, has connected with it a pipo, O, which will pass from any suitable supply of persulphate of iron or perehloride of iron, or other coagulating agent, which, by preference, will be in solution. The filter bed and the persulphate or perehloride of iron, or other coagulating agent, will meet at the juncture of the pipes, F and O, and then pass into- the filter together, with the result that the minute particles of foreign matter in the liquid will be sufficiently coagulated to permit tlieir arresta tion by tlie filtering agent. As I have stated, the proportions or quantities of the coagulating agent cannot be accurately defined. It is only necessary that a sufficient quantity be used to effect that degree of coagulation which will admit of the fine impurities being arrested from the water on its passage through the filter bed during a continuous process. It will be understood that in this process the coarse impurities present in the water may be arrested by tbo filter bed without coagulation. I may mention, as an illustration, that I have successfully purified the water of the Mississippi river at Now Orlen,ns by using about one-eighth of a pound of perehloride of iron, of from 50-° to 60° Baume, to- a thousand gallons of water. I do not. coniine myself to the employment of persulphate or perehloride of iron or permanganate of potassa, hut make use of any oilier suitable agent which is capable of coagulating the impurities of the liquid, and preventing their passage through (he filter bed. Neither do T limit myself to any particular proportions or quantities of the coagulating agent, as they may bo varied according to circumstances and the character of the liquid to he treated. Nor do I confine myself to any particular liquid, although I contemplate chiefly the purification of water in large quantities. It is obvious that, by the use of the uninterrupted process hereinbefore described, I entirely dispense with tbo employment of settling basins or reservoirs, as now commonly employed.”
The claim is as follows:
“The method hereinbefore described of arresting and removing the impurities from water during an uninterrupted passage of same from a supply pipe into a filtering apparatus, thence through a filter bed contained therein, and out through a delivery pipe leading therefrom, which method consists in introducing into .the water, simultaneously with its passage to- or into the filter, a substance which will sufficiently coagulate or separate the impurities to facilitate their arrest and removal by the filter bed, thus obviating the necessity of employing settling basins.”
The entire paragraph commencing with the words “I do not confíne myself” was disclaimed by the owner of the patent on July 24, 1889. It had long been known that alum and the salts of alumina and the persalts of iron were coagulants which, when placed in a vessel of turhid or impure water, coagulated or collected together the suspended inorganic or organic, but not the dissolved, impuri
“The filter bed, in the first place, catches along its tortuous passages minute particles of this gelatinous precipitate formed from the iron salt, and then the passages thus lined with this precipitate further catch and arrest other portions of the same, as well as particles of suspended matter. The filter bed likewise aids in the chemical reaction by which the gelatinous precipitate is formed, so that portions of gelatinous precipitate come into existence or are developed during the passage of the liquid through said filter bed, in consequence of the agitation to which said liquid is subjected in flowing through these tortuous passages, and thus the filter bed has its power of catching and arresting particles of suspended matter still further developed.”
It will thus be seen that tke action of the hydrate, in connection with a stream flowing upon a filter bed, was not simply a repetition of the'old process of subsidence or sedimentation. The invention thus used in connection with sand or gravel, or crushed-quartz filter beds, has proved to be exceedingly useful. Large quantities of water can be rendered pure with great expedition and economy. The process not only frees water from suspended impurities,, but greatly aids in freeing, and it is said to entirely free, it from bacteria or living organisms. It is also extremely useful in clarify
The fact of infringement depends upon the question whether the owner, by its disclaimer, so limited the claim as to exclude the use of alum or the salts of alumina from the protection of the patent. All the terms of the disclaimer are not easily to be understood. The patentee had given, no formula of proportions or quantities of the reagent, but had said that a sufficient quantity was to be used, and, by way of illustration, mentioned that a very small quantity, one which would naturally create surprise, was sufficient for the purification of the turbid water of the Mississippi. The disclaimer struck out the clause which stated that the patent was not limited to particular proportions or quantities, but, as, there was nothing in the patent which created a limitation, that part of the disclaimer simply brings into prominence the fact that, in the opinion of the patentees, small quantities only would be requisite for the purposes of the invention. The disclaimer also specified, what should ■never have been in doubt, that water was the only liquid to be purified, but it properly did' not say that the purification was for potable purposes only, nor that sand, or its equivalent granular material, made the only filtering bed suitable to be used. It is the natural, and probably the best, material to be used for the purposes of the invention. The patent was intended, before the disclaimer, to include any sub