287 F. 495 | 4th Cir. | 1923
The appellants were defendants in the court below, and they so will be designated in this opinion. The suit was brought for alleged infringement of two patents owned by the plaintiff company, namely, No. 1,152,222, issued August 31, 1915, and No. 1,090,651, issued March 17, 1914, both for improvements in underfeed stokers. The latter patent was withdrawn at the trial, and therefore has not been considered. The bill charges infringement of claims 3, 9, and 10 of patent No. 1,152,222, herein referred to as the Riley patent, and they, are the only claims in controversy. The trial court held these claims valid and infringed, and entered the usual decree for an injunction and accounting. 274 Fed. 864. From this decree the defendants appeal.
The Riley patent, No. 1,152,222, contains a statement to the effect that it is founded on a stoking apparatus of the type shown and described in the patent to Taylor, No. 792,862, and has for its object, among other things, the obtaining of a more complete combustion of the fuel used, and thus avoiding loss of fuel in the ash, which was found to be incidental to the operation of the Taylor stoker. Both the Taylor and Riley patents are fundamentally coking underfeed stokers, and the first of the kind that appears is shown in the patent to Jones, No. 470,052, which was followed by the Daley patent, No. 644,664.
In both the Jones and Daley stokers coal was introduced into a receptacle or retort, which had an open top, was closed at the sides and one end, and had the other end open to permit the entrance of coal. Into the lower part of the receptacle coal was forced through the open end by rams or pushers; the introduction of successive charges acting to force the fuel previously fed into the receptacle to the top of the latter. The upper portion of the body of coal as it emerged from the receptacle was ignited, and combustion of the fuel maintained and promoted, by forcing air under pressure across the fuel, through pipes in the Jones construction, arranged along the sides of the receptacle, and through twyer blocks, similarly arranged, in the Daley construction. In both of these structures the effect of maintaining combustion on the top of the mass of confined coal, from which air of an amount to cause combustion was excluded, was wholly or partially to coke the coal in the retort below the air supply. Consequently volatile gases were liberated from the coal, and these in rising mingled with
The practical defect in the Jones and Daley stokers was that an uninterrupted uniform burning of the fuel to maintain a constant heat could not be carried on, because at frequent intervals it was necessary to expose the fire bed to outside cold air during the removal of ashes. As fresh coal- was fed into the lower part of the retort, the coal previously received was coked, forced upward, and burned. Consequently the ashes from the burning fuel at the top were spread out from tiie sides of the retort and received upon dead plates extending laterally from the sides of the retort, and when the quantity of ashes was such as to interfere with the operation of the furnace rakes introduced through apertures opening into the outer air were used for their removal.
The admission of air in this manner cooled the interior of the furnace and required a large consumption of fuel to bring the temperature back to the required point after each ash removal. Besides, the ash was necessarily raked by hand, and this involved exhausting and expensive labor. The area of the dead plates which could be raked was limited, and consequently the size of the furnace was much restricted, and because of the location of the dead plates,' and the necessity for free access to them, it was impracticable to arrange the retorts in groups.
In the Taylor construction, retorts open at each end, and twyer blocks arranged on' both sides of the retorts for directing air under pressure, which is received from an air trunk, extending beneath and transversely of the retort to the fuel forced upward to the tops of the retorts by successive charges, and dump ash plates, arranged at the rear or discharge ends of the retorts and twyer blocks, are employed. The advantageous and distinguishing feature of the Taylor device is that the retorts and twyer block's are inclined downward from their feed to their discharge ends, and that therefore the fuel is moved from the point of introduction, through the combustion zone and to the point of its discharge upon the dump plates, by the combined action of the pushers and gravity. Moreover, the twyer blocks are of such form and arrangement in respect to the retorts that their upper faces form lateral extensions of the tops of the retorts. Consequently, as the coal is forced into the lower portions of the retorts, the burning coke at their tops flows out over and covers the twyer blocks, resulting in the maintenance of a continuous fire bed extending over the retorts and twyer blocks during the operation of the stoker. This construction permits of unlimited duplication of retorts and twyer blocks, thus allowing *the installation of a furnace of any desired size. The dump plates are inclosed by the walls of the furnace, and are operated from outside the latter, so that, of course, there is no cooling of the furnace incident to ash dumping.
In 1908 several of the Taylor stokers were placed with the Electric Corporation, of Lowell, Mass., and were used in connection with its plant for generating electricity for lighting purposes, etc., where the requirement for increased power at certain times of the day was imperative, Failure of the stokers properly to function under excess load conditions naturally led to the serious consideration of means for curing their inherent defects.
Riley, who was employed by the then owners of the Taylor patent, had several conferences with'representatives of-the Electric Corporation, among them James H. Wood, who was the engineer in charge of the plant of the corporation, at which conferences the defects of the stoker were discussed. Numerous suggestions as to changes , and additions were made, but, 'as the problem presented was difficult of solution, no remedy was quickly found. The requirements were many. A mere lengthening of the retorts ajid of the coacting elements would not avail, because in the end, under feed of large amounts of fuel, clogging would ensue. What was needed was some means whereby the partly consumed fuel 'which was deposited upon the dump plates, when large quantities of fuel were introduced, would entirely be consumed; to aid in producing the additional heat and to avoid waste-of fuel. For this purpose the dump plates had to be changed in form, so as to become in effect grates on which burning could take place, and air under pressure had to be supplied to promote combustion on them. Furthermore, the air had to be supplied to the grates in a manner to vary in quantity with that of the air which was supplied to the fuel at the tops of the retorts and on the twyer blocks, in order that it might be efficient during the feeding of either small or large quantities of fuel to the retorts, and the grates had to be capable of heing agitated to break up their load to permit the penetration of the air.
Riley had been trying since 1907 to devise means for overcoming the defects in the Taylor stoker above outlined, and at one of the conferences submitted a blueprint illustrating! a construction .he had thought of for the purpose. At this cpnference it appears that Wood indicated bn the blueprint some ideas which he had of additions in the. nature of improvements on the stoker. It may well be that the suggestions made by Wood were adopted by Riley and ultimately incor
This addition or improvement consists of a fuel support provided with an .interior air chamber mounted adjacent to the discharge ends , of the retorts in a manner to permit oscillation; the supporting surface being in the form of steps with air spaces between them communicating with the, air chamber, a connection between the air trunk and the air chamber, and means for oscillating the support. After passing through the usual preliminary stages necessary to ascertain its best operation and manipulation under varying conditions, it gave eminently satisfactory results.
“In reducing an idea of means to practice, an inventor Las a right to avail himself of the constructive skill and ingenuity of others; and the suggestions which he may derive from them, and the improvements which he may adopt in consequence of these suggestions, belong to the embodiment of his invention and not to' its essential character. Hence no notice is taken by the law either of the suggestions or their author.” The Law of Patents for Useful Inventions, Robinson, § 393.
The authority given, among others, for this statement, is the ruling of Mr. Justice Clifford in the leading case of Agawam Co. v. Jordan, 7 Wall. 583, 19 L. Ed. 177. The principle there laid down has, so far as we are aware, uniformly been adopted in subsequent decisions on the subject of suggestions to inventors.
In Keystone Mfg. Co. v. Adams, 151 U. S. 139, 14 Sup. Ct. 295, 38 L. Ed. 103, the court says:
“But when, in a class of machines so widely used as those in question, it is made to appear that at last, after repeated and futile attempts, a machine has been contrived which accomplishes the result desired, and when the Patent Office has granted a patent to the successful inventor, the court should not be ready to adopt a narrow or astute construction, fatal to the grant.”
The contention of defendants that the words “mechanism for operating the grate,” in claim 3, and “means for giving a limited oscillative movement to said support,” in claim 9, imply that such “mechanism” and “means” should be limited, and be effective only when construed to have read with and limiting them some words indicating that the operation is by and with the feeding ram, to cause the grate or support to feed the fuel, is not well founded. A reading of the specification of the patent shows that there is sufficiently dear disclosure of a construction to serve as a foundation for the claims as written. Two forms of oscillating means are described; one operated and timed by the movement of the feeding ram, and one operated by hand. The fact that two forms of oscillating means are described, one by hand, and one-by a connection with the feed plunger, and then in the claims terms covering both are used, does not warrant a construction of the claims limiting them to either form alone.
The record contains nothing to indicate that ample feed of fuel was lacking in the Taylor stoker. What was wanted was a more complete burning of the fuel. Hence the primary reason for oscillating the adjunctive overfeed grate was to agitate the fuel to allow air to pass from the interior of the grate up through the fuel to promote combustion on it, and not to aid in feeding the fuel by a continued movement.
“It is manifest, therefore, that it was not meant to decide that only pioneer patents are entitled to invoke the doctrine of equivalents, but that it was decided that the range of equivalents depends upon and varies with the degree of invention.”
The claims 3 and 9 as they appear in the Riley patent fairly well cover the features of the stoker to which they are directed, and it is not necessary to import to them the language of any of the claims stricken from the application by amendments in order that they may cover defendants’ stoker.
Claim 10 is a narrow one, which is directed particularly to the boxlike fuel supports in the form of steps, with air passages between the steps, and the brackets having conduits which communicate both with the air trunk and the interior of the fuel supports. The specific forms and arrangements of the parts as claimed are novel, so far as anything before us showing the prior state of the art is concerned, and the claim needs no forced construction to be held to cover the corresponding feature of the stoker produced by defendants.
Their stoker is made up of a number of retorts and twyer boxes alternately arranged and inclined downwardly from front to rear, an air chamber extending below and transversely of the retorts and twyer boxes, and inclined overfeed boxlike grates secured by brackets to the rear ends of the twyer boxes, in positions to receive fuel from the retorts and tops of the twyer boxes. The upper faces of the grates are stepped, and air openings are formed between the steps to allow air to pass upward from the interiors of the grates through the fuel on the grates. The brackets are hollow, and form conduits from the air chamber to the interiors of the grates. The grates are so disposed on the brackets as to allow them to oscillate. A shaft extends through the grates, and means for oscillating the grates through the shaft are •provided. The substitution of the air chamber for the air trunk of
In Winans v. Denmead, 15 How. 330, at page 343 (14 L. Ed. 717) the Supreme Court, in considering a patent having essentially narrow claims, says:
“Where form and substance are inseparable, it is enough to look at the form only. Where they are separable, where the whole substance of the Invention may be copied in a different form, it is the duty of courts and juries to look through the form for the substance of the invention, for that which entitled the inventor to his patent, and which the patent was designed to secure. Where that is found, there is an infringement, and it is not a defense that it is embodied in a form not described and in terms claimed by thé patentee.”
This case is cited with approval, among others, in Sewall v. Jones, 91 U. S. 171, 23 L. Ed. 275; Eddy v. Dennis, 95 U. S. 560, 24 L. Ed. 363; and Hoyt v. Horne, 145 U. S. 302, 12 Sup. Ct. 922, 36 L. Ed. 713.
The stoker art is an old one, and many forms of overfeed grates .are public property, which could have been used by defendants without infringing any existing patent. The fact that under these conditions they adopted a structure so very nearly resembling that of Riley is proof of the excellence of his improvement, and it also indicates the difficulty of devising means for reaching the desired end in any other way.
For these reasons we are of opinion that claims 3, 9, and 10 of the Riley patent are valid, and that, giving to their language its ordinary meaning, they are infringed by the defendants.
It follows that the decree appealed from should be affirmed.