Year: 1886

page_text: Date of Application, 22nd May, 1886.
Complete Left, 21st Feb., 1887.
Complete Accepted, 22nd Mar., 1887,
I, EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and Engineers,
of 35, Southampton Buildings, Chancery Lane in the County of Middlesex do hereby
declare the nature of this invention to be as follows:—
The improved firegrate applicable to furnaces of all kinds has cylindrical firebars
and consists of a horizontal and an inclined part and its shape and method of fixing
and operation are applicable to the furnaces of steam boilers and to other furnaces.
It does not form as is ordinarily the case a perforated or slotted partition to the
heating chamber but is placed entirely outside the latter in the space which forms
the ashpit.
The firegrate consists of heavy cylindrical iron bars of suitable length the ends of
which are reduced so as to form pivots which rest in notches or bearings on the
upper edge of parallel or other iron bars connected together so as to form a frame
which together with the bars is supported upon guides upon which it can be pushed
in or out the bars being arranged transversely across the furnace.
The surface of the cylindrical bars may be smooth or they may be provided with a
sufficient number of dove-tailed shape projections or teeth round their periphery so
that those upon one cylinder correspond with the spaces upon the adjoining cylinders.
The cylinders can therefore be turned round when necessary upon their pivots
without the teeth upon one cylinder catching those upon the adjoining cylinders, and
in this way they serve to scrape off any scale or scoria which may be formed upon the
adjoining bars by too strong a fire. This operation takes place when the fire is stirred
by turning the bars round with a suitable poker.
The diameter and length of these cylindrical bars will be varied according to the
kind of stove or furnace to which they are applied and the purpose for which they are
to be used and also to the kind of fuel which is to be burned. The ends of the bars
°

page_text: inside the pivots are made slightly conical so that they do not rub against the frame,
and in this way while the bars can turn easily they cannot vary their relative
positions.
The form and arrangement of the circular pivotted bars is the same on the inclined
part of the grate which is in the front of the furnace as in the horizontal part, and
instead of these two parts the entire grate may be made curved but the advantages of
combining the inclined part with the horizontal part are that the thickness of the fuel at
the front is reduced, sufficient entrance is given for the air for combustion, and the
ashpit is made more accessible.
It is important that the space between the lowest bar of the inclined grate and the
bars of the horizontal grate as well as that between the highest bar of the inclined
grate and the edge of the stove above should be sufficient to allow the introduction of
a suitable poker.
For cleaning the grate a fork may be introduced between the bars and the fuel so
as to allow the lower frame and bars to be withdrawn.
The grate being entirely separate from the combustion chamber renders possible
the admission of air to the fire round the whole of the grate between the latter and
the sides of the combustion chamber, this air current passing the part which is exposed
to the strongest heat and keeping it relatively cool. The circular bars facilitate the
fall of small particles of ashes between them. If such circular bars are placed in an
inclined or curved grate they will reject ashes nearly automatically by partially
revolving them. Moreover, by the cylindrical form of the bars in combination with.
the facility for turning them the step form. of the inclined grate is changed into a
single inclined face having few supports and friction points.
The advantages of the improved grate constructed and arranged as described are the
following:
It is easily adjusted in its place and removed; It is not liable to bend or break;
cannot injure the adjoining parts of the stove by expansion or alteration of shape;
Any parts requiring to be changed can be easily removed and others substituted ;
there is a sure and sufficient admission of air; the fire is easily stirred and the parts
of the grate readily cleaned and the particles of ashes do not accumulate on the bars.
Moreover, the grate is simple in construction and can be readily applied to existing
stoves or furnaces.
The 19th
A
100

page_text: These grate bars remain with their pivots in the notches which form bearings
for them.
The notches fit freely but closely against the pivots, so that the latter can easily
turn in them but that they cannot vary their position in the direction of the length of
the support.
An essential condition for the construction and the combination of a sloping grate
with cylindrical bars (as shewn in figure 1) is, that the spaces between its lowest bar
and the first bar of the horizontal grate, as well as the space between its highest bar and
the lower end of the exterior casing of the stove at this part, remain of such a width
that a poker of any suitable form can be introduced.
The isolation of the grate from the walls of the fireplace as shewn renders possible
the admission of air to the fuel round through the opening or space between the edge
of the grate and the fireplace sides. In this way also the sides of the fireplace, which
are exposed to the strongest fire, are preserved because through this part a
comparatively cool current of air passes.
The circular bars facilitate the fall of small particles of ashes and dross between
them.
If such circular bars are placed in a sloped or curved grate, they will reject ashes
and dross nearly automatically if caused to make a partial revolution. Another
advantage of the cylindrical form of such bars in combination with its easy turning is
that the stair form of the sloping grate (if flat bars are used) is changed to a single
inclined face having very few projecting parts and friction points.
A firegrate with circular bars constructed and arranged as described and shewn has
the following advantages.
It is easily adjusted in its place and removed.
It is not liable to bend or break.
It cannot injure the adjoining part of the stove by expansion or alteration of form.
Any parts requiring to be changed can be easily removed and others substituted;
There is a sure and sufficient admission of air; the fire is easily stirred and the parts
of the grate readily cleaned and the particles of ashes do not accumulate on the bars.
Moreover the grate is simple in construction and can be readily applied to existing
stoves or furnaces.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, I declare that what I claim is :-
The combined grate, applicable to furnaces and fireplaces of all kinds and consisting
of moveable cylindrical bars, arranged supported and operating substantially in the
manner and for the purpose described and shewn in the drawing.
This 91st dor of Fahr 1887