US25258A - Hollow grate-bab fob steam-boilers - Google Patents

Description

A B. L. GRIFFITH, HOLLOW GRATBBAR FOR STEAM BOILERS.

vNn. 25,258.,l Patented Aug-30, 1859.

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BENJAMIN L. GRIFFITH, OF READING, PENNSYLVANIA.

HOLLOW GBATE-BAR FOB. STEAM-BOILERS.

Specification of Letters Patent No. 25,258, dated August 30, 1859.

To all whom it may concern:

Be it known that I, BENJN. L. GRIFFITH, of Reading, Berks county, State of Pennsylvania, have invented a new and useful Improvement in Hollow Grate-Bars for Steam- Boilers; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing and to the letters of reference marked thereon.

y invention relates to an improvement in the construction of hollow grate bars for steam boilers, and my improvement consists in two or more t-ubes connected at each end to the hollow boxes which are attached to the irebox of the boiler by means of hollow screw plugs as described hereafter, so that the water in the boiler' can have a free circulation through thebars, and so that the latter can be readily removed and replaced in sections.

In order to enable others to make and use my invention I will now proceed to describe its construction and operation.

On reference to the accompanying drawing which forms a part of this specification, Figure l, is the sectional plan of the fire-box of a locomotive boiler with my improved hollow grate bars. Fig. 2, a sectional elevation of part of the fire box. Fig. 3, a transverse section of the same. Fig. 4, a detached view illustrating a modified plan of securing the grate bars to the lire box.

Similar letters refer to similar parte throughout the several views.

A, is the exterior, and B, the interior plate of a locomotive fire box, the usual water space intervening between the plates and the latter, being connected together by the ordinary stay bolts.

The grate bars consist of tubes o o, three four or more, of which, are connected at each end to and communicate with a hollow metal box D. Three or more sets of these bars, according to the size of the lire box, arc attached to the latter in the following manner. Each of the boxes D, have two openings on the outside and near each end, and each opening is counter-sunkso as to receive the bevel ed end of a hollow tapering screwplug G. The latter is screwed into the firebox through both plates, and has any convenient number of openings at a point between the inner and outer casing of the fire box, so that the water in the intervening space can pass through the hollow plugs into the boxes D, and thence into the pipes C, through which a circulation of water is constantly maintained.

Vhen one of the tubes becomes worn, burnt or otherwise damaged, the whole set of tubes to which the damaged tube may be connected is removed by partially unscrewing the plugs G, when the whole of the tubes with their boxes will drop to the ground, and a new set of tubes can be readily introduced. The damaged set may then be repaired at pleasure ready to take the place of another damaged set when necessary.

vInstead of connecting each set of hollow grate bars by screw plugs at both ends, they may be connected at one end by a simple tube o., Fig. 4l, which is screwed into the inner casing of the lire box, and which is beveled at the outer end so as to lit into the countersunk opening of the box D.

I am aware that hollow grate bars communicating with the water spaces have been heretofore used, also that hollow screw plugs have been employed for connecting detachable linings to the lire boxes of locomotives. I therefore do not claim the separate use of such devices, but

I claim as my invention and desire to secure by Letters Patent- Two or more, tubes C, att-ached to hollow boxes D, connected to the irebox, by mea-ns of hollow perforated screw-plugs G, and arranged in sets to complete t-he grate as and for the purpose herein set forth.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

B. L. GRIFFITH.

fitnesses HENRY HowsoN, JNO. B. KENNEY.

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