Improvement in Shaking and Chopping Grates for Stationary, Locomotive, or Marine Boilers.
Year: 1899

page_text: Date of Application, 24th Oct., 1899-Accepted, 17th Feb., 1900
COMPLETE SPECIFICATION.
Improvement in Shaking and Chopping Grates for Stationary,
Locomotive, or Marine Boilers.
I, JAMES REAGAN, of No. 237, N, Front Street, in the City and County of
Philadelphia, and State of Pennsylvania, United States of America, Engineer, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement.
My invention relates to that type of furnace grate known as shaking or rocking
grates in which the burning fuel is supported upon a series of longitudinal apertured
fire bars and movable hollow choppers; the office of the bars being to sustain or
bridge the fire when the choppers are operated to remove the ashes or clinkers.
The principal objects of my invention are- -First, to increase the efficiency and
durability of the fire bars, enabling them to resist the action of heat, to avoid
burning out, becoming warped or twisted. Second, to so construct the fire bars
to serve as guides in keeping the choppers in proper alignment and prevent them,
when oscillated, working under and lifting the bars from their seats. Thirdly, to
support the ends of the fire bars upon single lugs instead of the duplex lugs, as
heretofore, by this means the ends of the choppers are permitted to pass between
the sides of the bars without meeting with any obstruction, and at the same
time ashes or clinkers are prevented from accumulating at the extremities of
the bars to interfere with the expansion of the same. Fourthly, to keep the bed of
fuel which is carried by the grate, free from the clinker and ashes that would
retard the admission of air to the combustion chamber and to render the operation
of the choppers which are borne by the rocking bars easy of accomplishment.
The exact nature and details of my invention will be fully understood by the
following description and appended claims, in connection with the accompanying
drawings, in which
Figure 1, is a vertical longitudinal section of a portion of a grate embodying my
improvement.
Figure 2, is a vertical transverse section on the line A-B, of Figure 1, the
choppers and fire bars on the right being omitted.
Figure 3, is a side elevation, enlarged of one of the fire bars, one half of which
is in section and represents them properly seated on the supporting lugs.
Figure 4, is a bottom plan view of the bar, detached from the lugs.
Figure 5, is a vertical cross section on the line C-D, of Figure 3.
Figure 6, is also a vertical cross section on the line E-F, of Figure 3.
Figure 7, is a vertical longitudinal section of a modified arrangement of my
invention and shows the manner of operating the same.
Figure 8, is a cross sectional view on the line G-H, of Figure 7.
Figure 9, represents a chopper, detached from its bar.
Figure 10 & 11, show spanners through the medium of which bars are rocked.
Figure 12, is a view of a portion of one of the rocking bars.
Figure 13, is a cross sectional view of a fragment of a bar and chopper.

page_text: To attain the objects above mentioned the fire bars are each made hollow and
of reduced length with the sides or wings extended downwards to a considerable
depth so as to present relatively large heat radiating surfaces, and provided with
vertical air passages leading through the tops (of the bars) for the admission of air
to the fire, and with latteral openings for air to pass through to prevent them
becoming overheated. The bars are also provided with recesses at each end which
engage with single lugs formed on the transverse bridge bars and on the bearing
bars at the front and rear ends of the grate, so that when the bars are properly
seated on the lugs, the lugs will not extend into the path of and interfere with the
movements of the choppers which oscillate between the bars, and so that, owing
to the fact that the side wings of the fire bars extend below the axis of the
choppers, the tops of the choppers which may have some lateral movement, cannot
swing under and come in contact with the lower edges of the fire bars. The
aforesaid objects are further attained by the use of floating-choppers of peculiar
construction in connection with co-acting elements as will hereinafter appear.
The grate frame proper consists of two side bars, 1 & 2, between which are
journaled the rocking bars or shaft 3, carrying the choppers 4, and two transverse
bearing bars 5 & 6, at the front and rear ends, as shown in Figures 1 & 3 which
are provided with lugs 7, projecting inwardly to support the fire bars 8, at these
points and with cutting edges 9, to co-act with the choppers. Bridge bars 10,
which span the side bars are similarly furnished on both sides thereof with lugs 11,
to sustain the inner ends of the fire bars 8, and with cutting edges 12, to act in
conjunction with the choppers, as shown in Figures 1 & 2.
One or more bridge bars may be used and placed so as to divide the grate length-
wise into so many sections as desired, thus permitting short fire bars and choppers
to be used and thereby increasing the efficiency of the grate, inasmuch, as short
bars resist vertical deflection, and are not affected by expansion and contraction to
the same extent as longer ones, they are therefore much stronger and are not liable
to warp, and as the choppers are in short lengths the operation of shaking and
cleaning the fire is rendered easy.
The
The fire or grate bars 8, as stated, are each made in short lengths and consist of
a central longitudinal web 13, Figures 3, 4 & 6, on each side of which are depending
bracing and cooling wings 14, between which and the said web 13, are tapering air
spaces leading up and through elongated slots 15, at the top of the bar, for admis-
sion of air to the fire. The upper portion of the bar is curved and the ends for a
certain distance are made solid and provided with rectangular recesses or cavi-
ties 16 Figures 3, 4 and 5, extending from the bottom upwards to within a short
distance of the top, to accommodate the lugs 7 & 11, upon which they rest.
upper longitudinal edges of the said lugs 7 & 11, instead of being flat are made
angular and the upper portion of the cavities 16 are made to conform therewith;
and to insure a proper seating on the inclined sides 17, a small recess 18, is made
to receive the upper sharp corner on vertex on the lugs, as shown in Figures 2 and 5
The lugs 7 & 11, are narrower than the cavities 16, of the fire bars, and the bars
are so disposed with reference to said lugs that there is normally a space between
the ends of each lug and the inner end of each cavity, the object being to admit
of a universal or floating movement of the bar and to provide for its free longi-
tudinal expansion.
The fire bars 8, at each end were formerly supported upon double lugs spaced so
as to leave a vertical opening between them, into which passed the depending lugs
underneath the bars to retain them in position. These lugs projected somewhat
beyond the sides of the bars and the choppers in their descent were liable to strike
them to such an extent as to interfere with a free movement of the grate; pieces
of hard clinker or ashes also became jammed in the openings in such manner as
to hold the ends of the fire bars in a fixed position so that when expansion of the
bars took place they were liable to warp or curve upward in the middle.
The strength and rigidity of the fire bars are materially increased by the addi-
tion of metal at the wings, which is so distributed as to thoroughly brace all parts

page_text: as well as to expose relatively large areas of the bar to the cooling action of the
air in the ash pit of the furnace, and by making opening transversely through the
same for the passage of air, the cooling effects is enhanced and the possibility of
their becoming overheated, warped or twisted avoided.
The side wings 14, on the fire bars, also form guides for the choppers, which
are loose on the shafts, to prevent them working under the lower edges and lifting
the bars from their seats when the choppers are oscillated in the act of shaking
or dumping the fire. The said depending wings 14, have arches 19, formed on
their lower edges to pass over and clear the rocking shafts 3, when the fire bars
are in position.
The ends of the fire bars are arranged to overlap the bridge bars as well as the
bearing bars to prevent ashes or clinker becoming packed on the upper edges of
the same, and a small cavity or pocket 20, to retain particles of ashes is formed
on the upper surface or crown at or near the extremities, Figures 3 & 5;
as these ashes are non-conductors of heat they will protect the metal and prevent
the bars burning out at these particular points.
The hollow choppers 4, Figures 1, 7, 8 & 9, each consist of an elongated body of
suitable material provided with downwardly flared clearance openings 21, for the
passage of ashes, lateral clinker crushing teeth 22, and end cutters or clinker
cutting knives 23, which in the operation of the choppers co-operate with one of the
upwardly projecting cutting edges 9 & 12, upon the end cross bars and the
bridge bars.
By the use of this construction, I am enabled to readily crush, cut or dislodge
all clinkers which are caught between the choppers themselves, between the
bridge bars and choppers, and also between the end cross bars of the grate frame,
and cut away and remove all ashes and masses of clinker which form in the lower
layers of the incandescent fuel.
Each chopper has a recess 24, which is angular in cross section and corresponds
in shape to the angular portion 25, of the rocking bars 3. This recess 24, is some-
what larger than the angular portion of the bar so as to admit of a considerable
movement on the bar and to receive the floating effect of the chopper to which I
have already referred.
This construction is especially useful in connection with vehicles, such as loco-
motive engines whose movements impart a slight vibratory action to the floating
choppers and cause an automatic sifting out of the ashes as the vehicle pursues its
course. It is also useful in the particular that it admits of universal movements
of the choppers when they are shaken in the usual manner and a consequent
thorough agitation of the fuel in all directions and also because it allows large
pieces of clinker to pass between the choppers which may readily move in opposite
directions to afford a large space between them for that purpose.
A still further advantage of the universal and free mounting of the choppers
is that, when not wanted they do not have to be moved together as a dead weight,
for as they will necessarily stand in various slightly different positions, motion
will be necessarily imparted to them as the operating lever is actuated. This fact
renders the shaking of the grate comparatively easy of accomplishment.
The rocking bars or shaft 3, carrying the hollow choppers 4, are each provided
with a cylindrical portion 26 whose diameters are smaller than the entrance 27, of
any of the recesses 24, of the choppers so that the choppers may be placed upon
the angular rocking bars 3, and slipped into engagement with the angular
portions 25, thereof.
To actuate the grate, spanners of an ordinary type are used, the long ones 28,
being connected with the usual shaking lever 29, and the short ones 30, being
united to the long ones 28, by links 31, all of the spanners are provided with
recesses 32, which adapt them to be locked upon the angular portions 25, of the
5 rocking bars in the same manner that the choppers are held thereon, with them
however there is little or no play or looseness upon the bars as in the case of the
choppers.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
First: A fire or grate bar having a body portion provided with a plurality of
perforated bracing webs or wings, the said.webs or wings-having a relatively larger
area of exposed surface and being provided with recesses for the reception of rock
shafts.
Second: A grate or fire bar consisting of a body portion having a curved top, a
central longitudinal web, and depending wings adjacent to said web, the bars
having tapering air ports or slots arranged in parallel order and extending ver-
tically through the same on each side of the central web, and provided with a series
of openings or air passages extending latterly through the side wings and central
web, and the said wings or webs having a relatively larger area of exposed surface.
Third: The combination of fire bars having their body portion made solid at each
end and provided with recesses or cavities extending inwards from the ends and
open at the bottom, supporting lugs for the fire bars, and choppers lying between
said fire bars.
Fourth The combination in a rocking or shaking grate of fire bars, end bars
or supports provided on their inner sides with single lugs, arranged the proper dis-
tance apart to sustain the front and rear extremities of the fire bars, bridge bars
placed intermediate of said end bars and furnished on both sides thereof with
similar lugs to support the abutting ends of the fire bars, said fire bars having
longitudinal disposed recesses at the ends adapted to rest upon said lugs, and
Choppers situated between the said fire bars.
Fifth The combination in a rocking or shaking grate of side bars, bridge
and end bars provided on their inner faces with single independent angular lugs;
fire bars constructed to admit of longitudinal expansion on said lugs, and movable
hollow choppers located intermediate of said fire bars.
Sixth: A fire bar consisting of a main body portion, depending wings and a web
disposed between the wings, the body portion having vertical air passages which
are in communication with the open spaces between the wings and the web and
the wings and the web having transverse air passages which communicate with
said spaces.
Seventh: A fire bar having depressions or pockets in its ends for the reception
of ashes, and provided with end sockets below said depressions, in combination with
supporting bars having lugs on their inner faces extending into the sockets and
supporting the bars, the bars being shorter than the distance between the faces of
the supporting bars, and adapted to have a longitudinal expansive movement upon
said lugs.
Eighth The combination of a series of angular rocking bars, a set of spaced
hollow choppers mounted on each of said bars, stationary fire bars retained between
the choppers and means connected with the rocking bars for oscillating said
choppers.
Ninth A chopper for grates consisting of an elongated body having at its
ends downwardly projecting cutters and interior clearing spaces, an open socket
conforming to the angular portion of the rocking bars, the entrance to said socket
being wider than the diameter of the reduced or cylindrical part and narrower than
a diagonal of the bars.
Tenth: The combination of a series of angular rocking bars each provided at
intervals with reduced or cylindrical portions, and a series of hollow choppers and
spanners mounted on said bars, the choppers and spanners each having an open
socket conforming to the shape of the bars, the entrance to said sockets being
wider than the diameters of the reduced or cylindrical portions, and narrower than
a diagonal of the bars.
Eleventh A chopper for grates consisting of an elongated body having at its
ends downwardly projecting cutters, and interior clearance spaces, in combination

page_text: with a grate frame provided with intermediate and end bearing bars having
upwardly projecting cutters, and stationary fire bars located longitudinally be-
tween said choppers.