US1900530A - Grate - Google Patents

Description

March 7, 1933. J. s. THOMPSON GRATE Filed Aug. 19, 1930 INVENT 5, Law: f 5

ATTORNEY5 Patented Mar. 7, 1933 UNITED STATES- PATENT OFFICE JAMES S. THOMIPSON, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO FIREBAR CORPO- RATION, 0F CLEVELAND, OHIO, A CORPORATION, OF DELAWARE GRATE Application filed August 19, 1930. Serial Np. 476,265.

' This invention relates to grate bars, especially adapted for heavy duty purposes, as in locomotives, boiler furnaces, and the like, and it is concerned more particularly with a grate bar which comprises a carrier and a plurality of fuel-supporting units or crossbars removably mounted thereon.

In the co-pending application of Buckley, Serial No. 338,352, filed February 8, 1929, there is disclosed a grate bar of the general construction above referred to, the carrier and fuel-supporting units of the Buckley bar being solid and. ordinarily made of cast iron. The Buckley bar has proven highly successful and satisfactory in use, particularly in locomotives. As the latter have increased in size, however, the weight of the grate structure has required serious consideration and many railroads have adopted steel for their grate bars instead of the usual cast iron in order to lighten the weight. Steel bars of ordinary construction are unsatisfactory-because they sag and become distorted in service but even with that disadvantage the saving in weight has led to their adoption in many instances.

The object of the present invention is to provide a grate bar which affords the advantages of the Buckley construction but is of much lighter weight and this object is attained by making the fuel-supporting units hollow and of sheet stock.

For a better understanding of the invention, reference may be had'to the accompanying drawing, in which Fig. 1 is a sectional view through a grate bar of the invention showing a fuel-supporting unit in side elevation;

Figs. 2 and 8 are sectional views on the lines 22 and 3-3 of Fig. 1, respectively;

1 Fig. 4: is a fragmentary side elevation of the grate bar.

Fig. 5 is a view in perspective of a portion of the unit; and

Fig. 6 is a fragmentary plan view of the unit.

Referring now to the drawing, the grate bar comprises a carrier which includes a web 10 having an. upstanding centering flange 11, a bottom strengthening rib 12, a

shaker arm 13 projecting downwardly from the web, and upstanding arms 14: at the ends of the web provided with supporting means whichmay take the. form of trunnions 15.

Mounted on this carrier is a plurality of fuel-supporting units, each of which is hollow and preferably consists of a pair of steel plates 16, each provided with a peripheral flange 17 and the plates being placed with their concave faces opposed and secured together in any convenient manner, as by having their contacting flanges welded, Each plate is formed on its-outer face with a row of spaced lugs 18 defining passages 19 for the outward flow of air between them and extending upwardly. above the lugs are fuel supporting projections 20 preferably arranged in groups of four and separated by intersecting air channels 21 and 22, the latter communicating with the passages'19 so that air-may flow around all sides of each projection to the fuel, thus aflording wide and uniform air distribution. Preferably the middle lugs are united as indicated at 23 to give additional strength at the middle of the unit. v

In its lower edge, the unit is provided with a recess 24 having the same general shape as the cross-sectional shapeof'the carrier and at the entrance to the recess are spaced lugs 25. Preferably the unit rests on the flat surfaces 26 on the top of the web on either side of the flange 11 and'out of contact with the flange. The shape of the recess is such that the carrier and units have some freedom of relative angular movement when the carrier is rocked in the shaking and dumping operations and when this movement occurs, one or the other of the lugs 25 moves into contact with the under surface of the web so as to prevent further relative 'movement and to lock the unit to the carrier.

The spacing between the lugs 25 may be such that the units are freely removable from the carrier by being lifted 0E, in which case the unit is locked to the carrier only when the relative angular movement occurs,

or the lugs may be closer together than the greatest width of the carrier, in which event, the units cannot become accidentally dislodged. In the latter form, the ends of the web adjacent the trunnion arms are cut away slightly and these arms are made narrower than the distance between the faces of the lugs so that the end units on the carrier may be removed by being swung on an axis transverse to the carrier to free their lugs from beneath the web, the lugs then passing over the side edges of the trunnion arms as the units are removed.

The shaping of the plates 16 to provide the faces of the plates .with spaced lugs 18 and the tops of the plates with projections 20 serves another useful purpose in that the distortion of portions of the top and sides of the fuel-supporting unit adds stiffness and rigidity to those parts and consequently makes it possible to use a sheet stock of lighter gauge than would otherwise be necessary. Also this distortion of such portions of the plates out of their plane overcomes diiiiculties which otherwise might result from cumulative expansion effects. If the flat surfaces of each plate constituting a side of the unit lay substantially in a plane, it will be evident that the greater expansion at the top of the unit than at its bottom due to temperature differences would be likely to result in the side walls of the unit becoming bulged or warped, and such distortion due to temperature differences might result in cracking the welding securing the edge flanges of the two plates together. By distorting portions of the metal inthe two plates out of the plane ofthe top and side surfaces of the unit, cumulative expansion effects are avoided. The expansion of one part of the top now takes place in a direc tion different from that in which another part of the top expands and the same is true of the sides of the unit. By distorting the sheet stock at the top and sides of the unit to provide top projections and side lugs in the manner described, I obtain a'combustion efficiency corresponding to that afforded by the Buckley bar previously mentioned, but the metal constituting the top and sides of the unit may have portions distorted out of the plane thereof in othervways than that disclosed to provide the advantages of increased stiffness and non-cumulative expan sion.

It will be seen that in the new grate bar a substantial saving of weight is obtained by reason of the substitution of the hollow units of sheet stock for the solid cast units of the prior construction. The plates of which the units are made are produced of sheet steel by a succession of stamping operations and can be made at relatively low cost. These plates may then be welded together electrically so that the cost of the unit is relatively low. The units constructed in the manner described have the required strength in service and burning out or sagging of the units is prevented by reason of the flow of air in contact with all surfaces of each unit. WVhile the carrier bar in the form illustrated is made of cast iron, I contemplate that the carrier may be made of steel in which event the weight of the grate bar will be still further reduced.

I claim:

1. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of hollow fuel supporting units extending beyond the lateral edges of said member, each unit consisting of a pair of plates of sheet stock having portions remote from their edges distorted out of the plane thereof and serving to prevent cumulative expansion effects.

2. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of fuel supporting units extending beyond the lateral edges of said member, each unit being hollow and made up of a pair of connected plates of sheet stock shaped to define the chamber between them, each plate having a plane portion and portions of the plane remote from the edges of the plate distorted out of said plane and serving to prevent cumulative expansion effects.

3. A grate bar comprising a longitudinal member provided with supporting means at itsends and a plurality of fuel supporting units extending beyond the lateral edges of said member, each unitbeing made up of a pair of plates of sheet stock connected together but spaced throughout the major portion of their extent to define a chamber, each plate having portions spaced inwardly from its edges distorted out of the plane thereof and serving to prevent cumulative expansion effects. 7 Y

i. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of hollow steel fuel supporting units extending beyond the lateral edges of said member, each unit being formed of sheet stock, the sides and top surfaces of the units having portions bent out of the plane of the metal and serving to pre- I vent cumulative expansion effects.

5. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of hollow steel fuel supporting units mounted removably thereon, each unit being made of sheet stock with the sides and top of each unit having portions bent out of the plane of the metal and serving to prevent cumulative expansion effects.

6. A grate bar comprising a longitudinal member provided with supporting, means at its ends and a plurality of hollow fuel supporting units mounted thereon and held against accidental displacement, said units having a limited degree of freedom of angular movement relative to said member, and each unit being formed of sheet stock, the

top and sides of each unit having portions bent out of the plane thereof.

7. In a grate bar, a fuel supporting unit made up of a pair of concave plates of sheet stock secured together with their concave faces in opposition, said plates together defining a chamber and each plate having portions spaced inwardly from its edges distorted out of the plane of the plate to stiffen the plate and prevent cumulative expansion efiects.

8. In a grate bar, a fuel supporting unit made up of a pair of sheet steel plates having concave faces, said plates defining a chamber between them, and each plate having portions spaced inwardly from its edges bent out of the plane of the plate, said portions being connected on all sides to the remainder of the plate. I

9. In a grate bar,'a fuel supporting unit made up of a pair of plates of sheet stock Welded together along their outlines, said plates defining a chamber between them and each plate having portions remote from its edges and bent outwardly to prevent cumulative expansion effects. 7

10. In a grate bar, a fuel supporting unit made up of a pair of plates at least one of said plates being formed with spaced vertical lugs projecting from one face and provided with fuel supporting projections at the tops thereof, said plates being secured together to leave a space between them.

11. In a grate bar, a fuel supporting unit made up of a pair of pressed steel plates provided with fuel supporting projections along one edge, said plates having portions in contact but defining a space between them and being united.

12. In a grate bar, a fuel supporting unit comprising a pair of concave steel plates welded together with their concave faces in opposition, said unit having spaced lugs on at least one face extending away from one edge thereof, said lugs terminating in fiattopped fuel supporting projections spaced by air channels communicating with the space between said lugs.

13. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of hollow steel fuel supporting imits mounted removably thereon, each unit being made of sheet stock and having portions spaced inwardly from its edges distorted out of the plane of the metal and serving to prevent cumulative expansion efl'ects, said portions extending across the greatest dimension of the unit.

14. A grate bar comprisinga longitudinal member provided with supporting means at its ends and a plurality of hollow steel fuel supporting units mounted removably thereon, each units being made of sheet stock and having sides and a top, portions of said sides spaced inwardly from the edges thereof being bent out of the plane of the sides and serving to prevent cumulative expansion effects.

15. A grate bar comprising a longitudinal member provided with supporting means at its ends and a plurality of hollow steel fuel supporting units mounted removably thereon, each unit being made of sheet stock and having sides and a top, portions of said top being bent out of the plane of the top and serving to prevent cumulative expansion effects lengthwise and throughout said top.

16. A grate bar comprising a longitudinal member provided with supporting means at its ends and avplurality of hollow steel fuel supporting units mounted removably thereon, each unit being made of sheet stock and having spaced portions bent out of the plane of the sheet and serving to prevent cumulative expansion effects in a direction lengthwise of the unit and throughout the top thereof, each of said portions being connected on all sides of the remainder of the sheet.

In testimony whereof I afllx my signature.

JAMES S. THOMPSON.

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