APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE DISTRICT OF NEW JERSEY.
MR. CHIEF JUSTICE FULLER, after stating the case as above, delivered the opinion of the court.
Kearney and Tronson applied January 5, 1871, for letters patent for a certain "improvement in spark-arresters for locomotives," which application was rejected on reference to patent to James L. Vauclain, August 20, 1861, and after various amendments was allowed, and the patent issued April 11, 1871. The following is the specification of the application and of the patent as allowed, the parts stricken out by amendment being in brackets and the parts inserted being in italics:
"The improvement relates to effectually preventing hot coals passing from the chimneys of locomotives, [by a peculiar manner of] arresting them before they get to the chimney.
"On the forward end of a locomotive boiler is an extension, on the top of which is the chimney or smoke-stack. This receptacle of all that passes [from the fire] through the boiler flues to the smoke-stack is technically known as the smoke-head; the pipes from the boiler to the engine pass through the smoke-head, and the steam is exhausted thereinto from the cylinders. In the unoccupied space in this smoke-head we place a grate, [formed either with bars or of netting, or perforated plates; the shape is not material; we make them circular, as being most convenient in ordinary cases. It is best there should be a clear space on all sides or around the grate] the peculiar features of which are its perpendicular bars with fixed apertures sufficiently fine to stop the sparks that come from the fire, the size of the grate being determined by the area of opening needed for the regular draft and escape of smoke on kindling the fire, or when the engine is not in motion.
"Upon the top of the grating a tube or pipe is fitted, extending upward a short distance above the top of the smoke-head into the chimney. A space is left around the top of the pipe between the edges of the aperture in the top of the smoke-head and the pipe. This space is covered with netting or grating to prevent sparks or coals from passing through into the chimney.
"In the accompanying drawings, Figure 1 is a view, in section,
of the front of the smoke-head, with the gratings and pipe in position. Figure 2 is a side view of the end of the boiler and of the smoke-head. A is the boiler. B, the flues. C, the smoke-head. D, the grate. E, the pipe on the top of the grate. F is the netting closing the aperture between the pipe and the smoke-head. G is the chimney or smoke-stack; and I, the exhaust pipes from the engines.
"It will be seen that nothing but smoke and gas can pass the top netting F, and that no coals or dangerous sparks can pass into the chimney, they being arrested by the grate D without having received any impulse from the exhaust pipes. The strong draft created by the exhausting steam up the pipe into the chimney brings the coals and sparks to the grating against which they strike and fall harmless into the space in the smoke-head. [The force of coals drawn from the fire when impelled by the exhaust steam up the chimney is such as to cut through netting, and even cast iron over a quarter of an inch thick, in two or three months, in any description of spark-arresters located in the smoke-stack.]
"By our arrangement the gases that are returned by contrivances that turn sparks downward in the smoke-stack, and sometimes force open the fire-door, have a clear passage to the atmosphere.
"[What we claim and desire to secure is --
"1. The grate D, pipe E, the net or grate F, as and for the purpose specified and shown.
"2. Combining a spark-arrester with the smoke-head of a locomotive in the manner and for the purpose hereinabove set forth.]
"We disclaim all draft-regulating contrivances, and also all gratings with lateral adjustable openings. What we do claim as our improvement, and desire to secure, is -- The grate D with longitudinal bars, as and for the purposes specified and shown."
On June 7, 1872, Kearney and Tronson applied for a reissue, which was rejected on reference to James L. Vauclain, smoke-stack, August 20, 1861; Weideman, Major and Sample, spark-arrester, December 20, 1870; and James Smith, speak-arrester,
March 7, 1871; and after amendment was allowed, and the reissue granted December 10, 1872.
The following is the specification of the application and of the reissue as allowed, the parts stricken out being bracketed and the parts inserted italicized:
"Figure 1 is a vertical cross-section of the smoke-box of a locomotive with our improvements attached, and
"Figure 2 is a vertical longitudinal section of the same, and a portion of the boiler.
"The letters of reference indicate the same parts in both figures.
"A represents a portion of the boiler of a locomotive. B is a space, commonly called the smoke-box. CC are the flues at the point where they enter the smoke-box; E is a pipe extending from within the base of the smoke-stack down into the smoke-box, and commonly termed a 'petticoat pipe;' D is a grating placed at the lower part of the petticoat pipe to prevent any cinders or sparks passing into the same; F is a netting or grating placed around the top of the petticoat pipe so as to cover the annular opening caused by the difference in size of the upper part of the petticoat pipe and the bottom of the smoke-stack G. H is a piece of boiler plate or sheet iron placed at the bottom of the smoke-box in order to provide a flat surface for the grate D to rest upon, and is provided with holes, through which the exhaust pipes II pass.
"Our improvements relate to providing locomotives with a suitable device for preventing live coals, cinders, sparks, and like substances, which may leave the furnace, from passing into or out of the smoke-stack, and to retain them in the smoke-box, from which place they may be removed at pleasure.
"It has heretofore been the practice to cover the tops of smoke-stacks of locomotives with a wire netting or grating, for the purpose of preventing the escape of sparks and cinders; and, in some cases, an inverted metal cone is also placed in the centre of such netting or grating to ...