US2399618A - Grate and grate bars - Google Patents

Description

ay 7, 1946 A. BALMFIRTH 39,6%

GRATE AND GRATE' BARS Filed Feb. 27, 1945 2 Sheets-Sheet l May 7, 1946. A. BALMFIRTH @RATE AND GRATE BARS 2 Sheets-Sheet 2 -i/ l- Tsf Filed Feb. 27, 1945 Q Q LL o Patented May 7, 1946 UNITED STATES PATENT OFFICEv GRATE AND GRATE BARS Ontario, Canada Application February 27, 1943, Serial No. 477,492

9 Claims.

This invention relates to grates, and more particularly to a new and improved grate bar and to novel means for assembling a multiplicity of said grate bars in a grate.

It is one object of the present invention to provide a grate bar of improved construction which will be particularly adapted for use in the burning of low grade and fine fuels such as anthracite coal dust and the like.

Another object is to provide a grate bar which may be used to construct a grate providing maximum cross-draft through the fuel being burned thereon.

A further object is to provide a grate bar which is particularly adapted to assembly in side-by-side or end-to-end relation with other similar grate bars, and which when so assembled will engage and interlock with the similar bars adjacent thereto.

A still further object is to provide a grate bar having the above advantages which has one end provided with a downwardly inclined upper surface and the other end having its lower surface beveled upward and which when supported on complementary sloping surfaces is free to slide as it expands under the heat of use.

A still further object is to provide a grate of the above type with said inclined and beveled end surfaces formed in a plurality of levels arranged in stepped relation to form hook portions adapted to interlock with the corresponding ends of similar grate bars or with correspondingly formed, complementary supporting elements.

A still further object is to provide supporting and retaining elements or blocks for the novel grate bars of the present invention, and particularly to provide such supporting and retaining elements which are adapted to interlock with said grate bars as outlined above and which will nevertheless permit expansion thereof due to heat.

Many other objects and advantages will in part appear and in part be pointed out in the course of the following description of one or more embodiments of the invention, which are givenas non-limiting examples, in connection with the accompanying drawings, in which:

Figure 1 is a plan view of a grate bar embodying a form of the present invention;

Figure 2 is a plan View of three grate bars of the type shown in Fig. 1 assembled in position in a grate, together with a side bar and the novel end-locking blocks of the invention;

Figure 3 is a side view showing a grate bar of the type shown in Fig. 1 assembled in position with the novel end-locking blocks of the invention;

Figure 4 is a section on the line li-Il of Fig. 2;

Figure 5 is a section on the line 5--5 of Fig. 2;

Figure 6 is an elevation of the left-hand end in the drawing of the grate bar shown in Fig. 1;

Figure 7 is a similar view of the opposite end of the grate bar shown in Fig. 1;

Figure 8 is a view similar to Fig. 2 but showing a multiplicity of grate bars assembled both sideby-side and end-to-end;

Figure 9 is a view similar to Fig. 3 but showing a pair of grate bars assembled end-to-end;

Figure 10 is a view in elevation of the front or locking face of the front end-locking block shown in Fig. 9;

Figure 11 is a bottom view of the locking block shown in Fig. 10;

Figure 12 is a view similar to Fig. 10 of the rear end-locking block shown in Fig. 9; and

Figure 13 is a bottom View of the locking block shown in Fig. 12.

Referring particularly to Figs. 1-7, grate bar 2l] comprises essentially a middle portion 22 and two end portions 24 and 25. The upper surface of central portion 22 comprises two areas, a horizontal face 26 and a downwardly inclined face 28. The upper surfaces of end portions 24 and 25 similarly comprise horizontal areas 3G and 32, and downwardly inclined surfaces 345 and 35, which extend in the opposite direction with respect to the length of bar 2!) from downwardly inclined surface 28 of central portion 22. As is shown particularly in Figs. 4 and 5, the lower face of each of upper surfaces 26, 30 and 32 is beveled upward, as indicated at 36, in such manner that when two or more similar bars are assembled in side-by-side relation, inclined surfaces 28, 34 and 35 will pass freely under the corresponding horizontal surfaces of the bars adjacent thereto, as illustrated particularly in Figs. 5 and 6, and will dene therewith a multiplicity of inclined air passages 38. Along its lower side, bar 20 is provided with an integrally formed, depending web 4i] of substantially the same length as bar 2li but of substantially less thickness except at the ends thereof, as is described in more detail hereinafter.

End portion 24 of bar 2i) terminates in a downwardly inclined surface comprising two levels d2 and 44 arranged in stepped relation to form an upwardly projecting horizontal hook portion i5. End portion 25 terminates in a complementary, upwardly beveled surface comprising two levels 46 and 48 substantially parallel to surfaces i2 and 44 and similarly arranged in stepped relation to form a downwardly projecting, horizontal hook portion 50. At each end of bar 20, web 40 is substantially thickened to form a shoulder 52 adapted to maintain said bar in spaced relation with adjacent similar' bars when assembled to form a grate, as illustrated in Figs. 2, 5 and 6. Each of shoulders 52 is cut away at the lower side thereof to form a substantially vertical hook or stop portion 54, 55, the purpose of which will be explained hereinafter.

The preferred mounting means for the novel grate bar of the invention is illustrated particularly in Figs. 3 and 10-13. A pair of angle irons 56 and 58 or similar elements may be mounted in any suitable way within the furnace. Angle iron 56 serves to support one end of grate bar 20 and one or more front-locking blocks may be secured thereto in any suitable way, as by means 0f bolts 62. Angle iron 58 similarly has secured thereto, as by means of bolt 64, one or more rear end-locking blocks 65. Locking block 65 is provided with a downwardly inclined surface comprising two levels 66 and 68 arranged in stepped relation to form an upwardly projecting hook portion 70. Said surfaces are substantially parallel to the upwardly beveled end surfaces 4B and 48 of bar 20, and hook portion 'l0 is adapted to engage hook portion 5!! of said bar, as is shown particularly in Fig. 3. The bottom portion of block 65 is preferably cut away to provide it with a plurality of reinforcing ribs 12, as is shown particularly in Fig. 13. Inner edge '|4 of block 65 comprises a stop portion adapted to engage complementary stop 55 of bar 20.

In operation, end portion 24 of bar 20 preferably rests on angle iron 56 and is retained in position by front-locking block 60. As is shown particularly in Fig. 3, locking block B0 is provided with a downwardly extending hook portion 'l5 adapted to engage hook 45 on bar 20 and formed by upwardly beveled surface 16 adapted to engage complementary surface y42 of bar 20 and a cutaway portion at 18. Preferably the lower side of block 60 is provided with a plurality o-f reinforcing ribs Tl corresponding to ribs 'l2 on block 65.

At the side, grate bars 20 are preferably held in position by a suitable side-locking bar 80, the ends of which conform similarly to those of bars 20, but the outer side of which is provided with a suitable shoulder 82 adapted to engage any suitable support within the furnace. Along its inner side bar 80 has a projecting rim 84 adapted to abut the vertical sides of the adjacent bar 20, but the lower side of which is beveled away at 85 to overlap the downwardly inclined side surfaces of the adjacent bar 20, as is shown particularly in Figs. 4 and 5. It will be understood that when a multiplicity of bars 20 are arranged in the grate, there will be a complementary side-locking bar (not shown) at the other side of the grate.

It is believed that the operation and advantages of the novel grate bar construction of the present invention will largely be apparent from the foregoing description. The construction and use of locking blocks B0 and 65 provide greatly simplified positive mounting means for the grate bars. In particular, their construction and the complementary construction of the ends of said bars permit substantial expansion of said bars as a result of heat, thus preventing buckling and breaking. Referring particularly to Fig. 3, it will be seen that as said bars are heated and expand, they are free to move to the right in the drawing and to slide diagonally upwards along surfaces 66 and S8 of block 65. At the same time, stops 54 and 55 will prevent excessive expansion by moving into engagement with the edge of angle iron 56 and inner edge 'I4 of block 65. On the other hand, after the fire is out and the grate bars cool and contract, the engagement of hooks 45 and 'l5 and hooks 50 and 'I0 will retain the bars in position and prevent excessive contraction. Another advantage resulting from this construction is the ease of removal 0f a broken or defective bar. It will be seen that in order to remove or replace a bar, it is necessary only to unbolt and lift front block 60 and one of side bars 80.

The design of the novel grate bars of the invention is also important by reason of the improved combustion afforded thereby. The relatively wide mesh provided by sloping surfaces 28, 34 an 35 permits even and more effective draft, thus promoting greater elciency of combustion and substantially eliminating the possibility of dead areas in the fire due to insufcient draft. A substantial advantage resulting from these features is the adaptability of the grates of the invention to the burning of low grade and fine fuels, such as anthracite coal dust and the like. Many additional advantages resulting from the novel aspects of the grate bar of the invention will doubtless be apparent to those skilled in the art, and it will be understood that the many modifications which may be made in the above-described embodiment of the invention without detracting from the essentials and advantages thereof are to be construed as coming within the scope of the invention.

A further important advantage of the grate bars of the invention is illustrated particularly in Figs. 8 and 9, and is their adaptability to use in end-to-end relation to provide grate surfaces of large area. Fig. 9 shows a grate comprising a multiplicity of grate bars |00 and 0| of the same design as grate bar 20 and arranged in both sideby-side and end-to-end relation. As is shown particularly in Fig.9, the engagement between the rear end portion of each of bars |00 and the front end portion of each of grate bars 20| is substantially the same as between rear end portion 25 of grate .bar 20 and locking block 65 described above in connection with Fig. 3. Otherwise the mounting of this grate is substantially the same as when a single series of grate bars is used, with the exception of I-beam |02 which may be conveniently used to support the middle portion of the grate. Angle iron |04 and rear locking block |05 correspond to angle iron 58 and locking block 65 in Fig. 3, and similarly front locking block |06 and angle iron |08 correspond to front locking block 60 and angle iron 56 in Fig. .3'. Side locking bar ||0 corresponds to side locking bar in Figs. 2, 4 and 5, and it will be understood that bar ||0 may be of integral construction throughout or may preferably comprise a series of sections laid end to end in a manner analogous to grate bars |00 and |0|. It will further be apparent that there may be additional series of grate bars laid end to end with .bars |00 or |0|, and that the only additional elements needed in this case will be a further I-beam |02 for each additional series of grate bars.

It will be seen that the grate shown in Fig. 8 affords all of the advantages of the grate described above in connection with Fig. 2. It will be apparent that grate bars |00 and |0| are free to expand longitudinally in the direction of both ends thereof, sliding over locking blocks |05 and at their outer ends and over their engaging end portions in the. middle of said grate. A particularly useful feature. of this construction is that it tendsV to preventv an undesirable feature previously found in grates of analogous construe.- tion, namely, the tendency of the ends of the grate bars to rise vertically and burn as a result of buckling of the bar.

Since certain changes may be made in the above product and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intendedto cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. A grate bar comprising a substantially elongated body comprising a middle portion and two end portions, each of said portions having a portion of the upper surface thereof inclined downwardly in a direction substantially at right angles to the length of said bar, adjacent bar portions having the upper surfaces thereof downwardly inclined in op-posite directions, and each of said bar portions having a portion of the lower face thereof beveled upward on the side opposite said downwardly inclined surface, and a depending web of substantially the same length as said bar integrally formed therewith and of substantially less thickness, the ends of said web being substantially thicker than the remainder thereof and being thereby adapted to maintain said b-ar in spaced relation with adjacent similar bars when assembled in a grate, each of said thickened end portions of said web being notched at the end thereof to form a substantially horizontal supporting surface and a substantially vertical, downwardly extending stop portion.

2.A A grate bar comprising a substantially elongated body comprising a middle portion and two end portions, each of said portions having a portion of the upper surface thereof inclined downwardly in a direction substantially at right angles to the length of said bar, adjacent bar portions having the upper surfaces thereof downwardly inclined in opposite directions, and each of said bar portions having a portion of the lower face thereof beveled upward on the side opposite said downwardly inclined surface, one end portion of said bar terminating in a downwardly inclined surface comprising two levels arranged in stepped relation to form an upwardly projecting hook portion and the other end portion having its lower surface beveled upward in a direction substantially parallel to said downwardly inclined surface of said rstnamecl end portion and comprising two levels arranged in stepped relation to form a downwardly projecting hook portion.

3. A grate bar comprising a substantially elongated body comprising a middle portion and two end portions, each of said portions having a portion of the upper surface thereof inclined downwardly in a direction substantially at right angles to the length cf said bar, adjacent bar portions having the upper surfaces thereof downwardly inclined in opposite directions, and each of said bar portions having a portion of the lower face thereof beveled upward on the side opposite said downwardly inclined surface, and a depending web of substantially the same length as said bar integrally formed therewith and of substantially less thickness, the ends of said web being substantially thicker than the remainder thereof and being thereby adapted to maintain said bar in spaced relation with adjacent similar bars when assembled in a grate, one end portion of said bar terminating in a downwardly inclined surface, said surface comprising two levels arranged in stepped relation to form an upwardly projecting hook portion, and the other end portion having its lower surface beveled upward in a direction substantially parallel to said downwardly inclined surface of said first named end portion, said surface comprising two levels arranged in stepped relation to form a downwardly projecting hook portion;

4. In a grate, the combination comprising a plurality of grate bars laid end to end, each of said bars comprising a substantially elongated body, one end of each of said bars terminating in a downwardly inclined surface, said. surface comprising two levels arranged in stepped relation to form an upwardly projecting hook portion and the other end of each of said bars having its lower surface beveled upward in a direction substantially parallel to said downwardly inclined, iirst named end surface, said surface comprising two levels arranged in stepped relation to form a downwardly projecting hook portion, said beveled surface and downwardly projecting hook being adapted to engage said downwardly inclined surface and upwardly projecting hook of the bar adjacent thereto.

5. In a grate, the combination comprising a plurality of grate bars laid end to end, each oi" said bars comprising a substantially elongated body, one end of each of said bars terminating in a downwardly inclined surface, and the other end of each of said bars having its lower surface beveled upward in a direction substantially parallel to said downwardly inclined, first named end surface, said beveled surface being adapted to engage said downwardly inclined surface of the bar adjacent thereto, supporting means positioned below said engaging b'ar ends, said bars being superimposed on said supporting means and each being slidable in the direction of the length thereof with respect to each other and said supporting means, and stop means on each of said bars cooperating with said supporting means for preventing said sliding movement of said bars from exceeding a predetermined limit.

6. In a grate, the combination comprising a multiplicity of grate bars arranged in side-byside relation, each of said bars comprising a substantially elongated body, means for supporting one end of each of said bars, said bars and said supporting means having complementary bearing surfaces, said bars being superimposed on said supporting means with their respective bearing surfaces in slidable contact in the direction of the ends of said bars supported thereby, said supporting means including means for locking said bars against sliding movement in the opposite direction beyond a predetermined point, the opposite end of each of said bars terminating in a downwardly inclined surface comprising two levels arranged in stepped relation to form an upwardly projecting hook portion, means for supporting said bar ends, and means for retaining said ends in position, said retaining means including an upwardly beveled lower surface having a lower portion thereof cut away to form a downwardly projecting hook portion, said upwardly beveled surface and downwardly projecting hook portion being adapted to engage said downwardly inclined surfaces and upwardly projecting hook portions of said bars, and means for securing said retaining means to said supporting means.

7. In a grate, the combination comprising a plurality of grate bars arranged in side-by-side relation, each of said bars comprising a substantially elongated body, one end of each of said bars terminating in a downwardly inclined surface defining with the plane of the upper surface of said bar an obtuse angle and the other end of each of said bars having its lower surface beveled upward in a direction substantially parallel to said downwardly inclined, first-named end surface, said beveled surface defining with said plane of said upper surface of said bar an acute angle, and means for retaining said bars in position in said grate, said means comprising a plurality of end-locking blocks, one of said blocks being provided with a downwardly inclined surface adapted to engage said beveled end surface of said bars, and the other of said blocks being provided with an upwardly beveled surface adapted to engage said downwardly inclined end surfaces of said bars.

8. In a grate, the combination comprising a multiplicity of grate bars arranged in side-byside relation, each of said bars comprising a substantially elongated body, one end of each of said bars having its lower surface beveled upward, said surface comprising a plurality of levels arranged in stepped relation to form a downwardly projecting hook portion, means for supporting said bar ends, said supporting means being provided with a plurality of downwardly inclined surfaces arranged in stepped relation to form an upwardly projecting hook portion adapted to engage said downwardly projecting hook portion on said bar ends, the opposite end of each of said bars terminating in a downwardly inclined surface comprising two levels arranged in stepped relation to form an upwardly projecting hook portion, means forfsupporting said bar ends, and means for retaining said ends in position, said retaining means including an upwardly beveled lower surface having a lower portion thereof cut away to form a downwardly projecting hook portion, said upwardly beveled surface and downwardly projecting hook portion being adapted to engage said downwardly inclined surfaces and upwardly projecting hook portions of said bars, and means for securing said retaining means to said supporting means.

9. In a grate, the combination comprising a multiplicity of grate bars arranged in side-by-side relation, each of said bars comprising a substantially elongated body, means for supporting one end of said multiplicity of said bars, the opposite end of each of said bars terminating in a downwardly inclined surface, a second multiplicity of grate bars similar to said first named multiplicity and arranged in end-to-end relation therewith, the end of each bar in said second multiplicity adjacent said first multiplicity havin-g the lower surface thereof beveled upward substantially parallel to and superimposed upon said downwardly inclined end surface of one of said rst multiplicity of bars, supporting means positioned below said engaging bar ends, said bars being superimposed on said supporting means and each being slidable in the direction of the length thereof with respect to each other and said supporting means, stop means on each of said bars normally spaced from said supporting means and cooperating therewith for preventing said sliding movement of said bars from exceeding a predetermined limit, and means for supporting the opposite end of said second multiplicity of bars.

DOROTHY B. BALMFIRTH, Heir and Acting Attorney in Behalf of All the Other Heirs of the Estate of Alfred Balmfirth, Deceased.

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