f NITED. STATES:

PATENT Grimes.

VILIJIAM DUFF, O'Iii AIITIM'ORVE, MARYLAND.

Specification forming part of Letters Patent No. 4,217, dated September 30, 1845.

T0 all whom it 772/6051/ concern:

Beit known that I, WILLIAM DUFF, of the city and county of Baltimore, and State of Maryland, have invented new and useful Im-` provements in the Method of Arresting and Consuming Sparks in the Chimneys of Locomotives and other Steam-Engines; and I do hereby declare that the following is a full, clear, and exact'description of the principle or character thereof which distinguishes it from all other things before known, and of the manner of making, constructing, and using known consists in makipg the side of the perforated tubes which surround the central tube of the chimney and through which the smoke and other products of combustion have to pass of imperforated sheet metal, to avoid the direct action of the exhaust from carrying sparks through the perforations in the Y tubes, and also in making a communication between the spark-reservoir around the chimney and a space at the lower part of' the smoke-box made by apartition therein, which space communicates with the lire-chamber by means of a tube or tubes corresponding with the ues, but below them, so that the action ofmthe exhaust in producing a draft through the lues partly exhausts the tubes below the ues, and thereby tends to draw all the sparks back into the fire to be consumed, while at the same time this back current tends to keep theperforated surfaces clear for the passage of the smoke, dac.

In the accompanying drawings, A represents a locomotive-boiler of the usual construction with ahrc-chamber or., tlues h, smokebox c, and chimney d. The chimney cl is su rrounded by an outer casing e to form a receptacle for catching the sparks, which is enlarged at the upper end for the reception of a series of tubes f, arranged around the chimney and parallel to it, and extending from a flatring g (that projects from the upper end of thechimney toward the enlarged part of the surrounding case, but leaving'a sufcient space between them for the passage of sparks) to the top or cap-plate h which is pierced with holes to correspond with the' ends of the tubes f, and a central hole immedi-atei y above and of the same size as the chimney, for the escape of smoke, die. The

fiat wing g isperforated with small holes at the ends of the tubesf, and its outerperiphery is cutout to leave a space betweenit and a series of vertical tubes t', attached to the surrounding case c and extending from near the top to within a short distance of the bottom of theenlarged part of the surrounding case. These tubes may be dispensed with and a space between two concentric rings substituted. The central holes in the cap-plate 'h are governed by a damper or valve k Z, the

upper one 7c to close the central hole in the cap-plate, and the iower onelis made with its under face concave, and to it is attached an inverted cone m, the base of which is of less diameter than the damper, and the two are attached together and suspended by a jointedv link n to a lever o, by which they are operated.

The series of tubesf may be made of any desired form in their cross-section, although I prefer that given in the accompanying drawings, which consists in making the face toward the chimney of two planes .at right angles to each other and at an angle of fortyfive degrees with the sides, which are connected together bya semicircle. Theface toward the chimney is to be imperforated and the sides and back perforated in the usual manner, or made of wire-gauze, for the passage of smoke and othergaseons products of, combustion, but to intercept the sparks. In their vertical section I prefer to make them larger 'at top than bottom.

The smoke-boX is divided into two compartments by a horizontal partition p, and a communication is establishedbetween the lower chamber and the receptacle for sparks around the chimney by means of a vertical tube q. This partition is placed just below the lower range of iiues b and above a range of fines or a single flue r, which correspond with and would operate as fiues were it not for the partition p, but which in consequence of this form a communication between the compartment below the partition and the fire box or chamber a to reconduct the sparks from the chamber around the chimney to the fire-box, there to be consumed.

For the purpose of firing up, at which time a free and strong draft is required, the double valve or damper 7c l is .suspended midway between the top of the chimney d and the cap-plate h, so that the smoke and other products of combustion pass directly out the in-l it around the edge of the valve; but when it is desired to arrest the sparks the double valve or damper is drawn up so as to close the central aperture in the cap-plate h. The smoke, sparks, and other products of combustion are carried up by the action of the exhaust-steam as generally employed against the inverted cone and curved surface ofv the damper l, by which they are deflected and thrown against the imperforated surface of the tubes f, thus directing the sparks against the outer casing, from whence they will fall through thespace between it and the edgel of the fiat ring g into the receptacle for them, while the current of smoke and other gases still under the influence of rarefaction, &;c., pass through the perforations in the tubes f, and then through the open ends at top. The few sparks that by the force of 'the current reach the cap-plate are carried into the tubes t', attached to the outer case, or a space formed by two concentric rings as a substitute and equivalent therefor, and thence down into the spark-receptacle. From' this receptacle the sparks are carried down by the vertical tube q into the chamber below the smoke box formed by the partition p, and from this they are drawn by the action of the current into the tire-chamber ct, to be consumed, for it will be evident that the action of the raretied air and the exhaust-steam produces a current into the fire chamber, and that this draft will necessarily cause the sparks to fall into the spark-receptacle, instead of adhering, as they frequently do in other sparkfarresters, to-the perforated surfaces, to the obstruction of the draft. The double damper or valve lo Z is provided with a rod or cord to be at the command of the engineer or fireman.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. The arrangement of thev seriesl of tubesfor conducting the sparks into the receptacleL that-are carried by the force of the current up to the top, as herein described.

4. Connecting the fire-chamber with the receptacle for the sparks made in the lower part of the smoke-box by a partition therein by means of a lower tube or range of tubes corresponding with the flue-tubes, so as to carryl back the sparksto the fire-chamber by an arrangement entirely within the casing of the boiler and furnace and acted upon by the current, as herein described.

WILLIAM DUFF.

Witnesses: y

SHEPARD STAMMERS, PETER MoWEL.