Improvements in Movable Furnace Grates.
Year: 1899

page_text: Date of Application, 4th Feb., 1899-Accepted, 8th Apr., 1899
COMPLETE SPECIFICATION.
Improvements in Movable Furnace Grates.
I, ETIENNE THÉODORE MOUTTE, of La Ciotat (Bouches du Rhone), France,
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, reference being had to the accompanying drawings and to
the letters and figures marked thereon, that is to say :-
This invention relates to an improved movable furnace grate which possesses
considerable advantages over all systems now in use.
In order that the said invention may be readily understood, I will describe the
same fully with reference to the accompanying drawings, in which:
Fig. 1 is a longitudinal section of the said grate.
Fig. 2 is a plan thereof.
Figs. 3 and 4 are views in two positions of one form of fire bar employed therein.
Fig. 5 is a transverse section of one of said bars.
Fig. 6 is a side view of a rocking piece hereinafter described.
Fig. 7 is a vertical section taken on the line A B of Fig. 6.
Fig. 8 is a horizontal detail section on the line C, D of Fig. 6.
Fig. 9 is a plan of the rocking piece.
Fig. 10 is a view of another form of fire bar for use with said grate.
Figs. 11 and 12 shew a recessed or notched support for use therewith.
Figs. 13 and 14 shew a front view and a section of a knife edge from which the
support is hung.
Figs. 15 and 16 are longitudinal and plan views of an extension piece for the
operating handle.
Fig. 17 is a face view of an automatic locking arrangement in its two positions
(closed and open).
Fig. 18 is a side view of the same.
The fire bars a, a, of the grate (Figs. 1, 2, 3, 4, 5 and 10) each consist of two or
more lengths of cast or wrought iron, of any suitable section, connected together side
by side by any appropriate means. They are interchangeable and reversible because
only a single type of bar is employed, and because of the simple arrangement of the
recesses b (Figs. 1, 3, and 4). These recesses in the bars fit on the pins d of the
supports e (Figs. 1, 6, 7, 8 and 9.
The various movements these bars are capable of receiving, will be seen from
the following description of the different parts of the mechanism.
The bars are arranged in two sets, those of one set alternating with those of the
other. Fig. 3 shows, for example, an even bar, and Fig. 4 an odd bar. They are
reversible as they can be turned end for end. Fig. 4 would then show the even bar
and Fig. 3 the odd bar. The possibility of being able to turn the bars end for end
allows of their being used for a longer time, experience having demonstrated that
fire bars become worn more rapidly at the front of the furnace than at the
rear.
These bars can be fitted in place through the furnace door, and can also be easily
replaced, in case of damage to one or more, without removing the fire from the grate.

page_text: For this purpose, the area of the grate is completed at the front end by a transverse
portion c (Figs. 1 and 2) which consists of two or three lengths like the fire bars. It
is made up in sections to facilitate handling, and is fixed to the front plate in
any suitable manner. It prevents the bars coming off the pins d of the
supports.
This arrangement permits of a bar being replaced whilst the fire is on the grate,
for which purpose it will only be necessary to effect the following series of
operations
_
1. Remove the fire from the bar,
2. Withdraw the corresponding section of the front portion c.
3. Draw the bar towards the front of the furnace in order to disengage the
pins & from the recesses b,
4. Raise the bar at its end before drawing it out of the furnace,
It is only necessary to reverse the operation at each stage, when a fresh bar is
to be put in.
The form of bar and support shewn in Figs. 10, 11 and 12, is the converse of
that just described, the pins being placed on the bars at 8, and the supports being
provided with recesses t like those in the bars shewn in detail in Figs. 3
and 4.
By this means the bars preserve their original properties, remain interchangeable
and reversible, and can be fitted in place through the furnace door. Their
manufacture is as simple as that of sectional iron hars, and thus they preserve
the whole of their resistance as they are no longer recessed or cut away.
The supports e are capable of sliding on movable bearer bars f (Figs. 6, 7 and 9),
which are made quite straight, and the said supports can be fixed thereto by
means of bolts. This arrangement of supports e permits of the distance between
the bars being regulated and determined according to the fuel employed. Two of
these supports are employed for each bar, and thus the bars a can be positively
connected with the bearer bars f whilst keeping them separated from the said bearer
bars so that the air may freely circulate through all parts of the grate and prevent
any over heating.
The bearer bars f are supported, in their turn, by the rocking pieces 9 (Figs. 1, 6,
7 and 9) which connect them in pairs. These rocking pieces oscillate on knife
edges h (Figs. 1, 13 and 14) which reduce to a minimum the friction and do
away with the inconveniences inherent to plummer-blocks and like bearings. Said
rocking pieces are also connected in pairs by adjustable connecting rods (Figs. 1
and 2). These rods are screw threaded at one of their ends, thus permitting, hy
means of nuts, the adjustment of their point of attachment with the rocking
pieces. They serve to regulate the position of the rocking pieces in such a way
as to obtain a perfectly uniform grate surface. It will be seen that the rods
connecting the rocking pieces at the front with those at the rear of the furnace,
form with the grate bars an arrangement such, that when the even bars are
raised, the odd bars will be lowered, and vice versa. For this purpose, all the
supports of the even bars, for instance, are fixed on the bearers fat the rear
of the rocking pieces g, and all the supports of the odd bars on the bearers f at ·
the front of the rocking pieces, or inversely.
The different movements of which the bars a are capable have thus been
shewn.
The general arrangement is completed by a lever j, connected to the middle of the
front bearer bars (Figs. 1 and 2), which by means of an extension k (Figs. 1 15 and
16) serves to impart movement to the whole grate.
This extension piece k, constitutes, with a catch m, a safety device or locking
arrangement which will now be more fully described. Its objects are to ensure, after
each operation, the exact return of all the bars into the same plane and to keep them
in this position, as well as to limit the working stroke, that is to say, the extent of
movement of the grate, to the amount deemed necessary.

page_text: In order that the function of the automatic catch m may be readily understood,; I
will now describe it with reference to Figs. 15 to 18.
The said catch is provided with a counterweight n, and is jointed on a bracket po
(Figs. 17 and 18) which is itself fixed to the front plate of the furnace, (Fig. 1).
This bracket o has cut in it a slot and has also a notch p. The length of the slot
corresponds to the stroke of the lever j. The notch is to allow of the nib or projection q
of the extension k (Figs. 15 and 16) passing through. This extension can, by means
of a projection or socket k¹ it carries, be fitted to the lever j, but only when this lever
properly occupies the locked position shewn in Figs. 17 and 18, this being the only
position in which the bars are in a uniform plane, and in which the notch p in the
bracket is opposite the nose or projection q of the extension at the moment that the
latter is introduced, or withdrawn.
It will be seen that on fitting the said extension to the lever j, the catch m will
slide over the inclined face of the nose q and the lever ; will be disengaged so that it
can be depressed in the slot, thus operating the bars. On the lever ; being restored
to the position corresponding to the uniform plane of the bars, and the extension
being withdrawn, the hook m engages, by its own weight, with the lever j, which
becomes absolutely fixed in the desired position.
It will be seen, from the preceding description and the drawings, that this grate is
perfectly balanced and that it is only necessary to use a very slight force to impart
the necessary movements to it.
It will also be seen that by working the lever j up and down, the alternating and
parallel reciprocating movement of the bars is obtained. This operation being
repeated at suitable intervals, will ensure the fall of the ashes and cinders, and will
maintain a perfect air supply over the grate area.
The improved movable grate renders the cleaning of the
caked clinkers can be separated and removed from the bars
lever i, by means of the extension k.
This said grate thus has the following advantages :-
grate easier, and any
by a few jerks of the
1. Simplicity of operation, and particularly the suppression of friction by the
suspension on the knife edges.
2. Facility for regulating the grate surface and the distance between the bars.
3. Interchangeability of all the parts, thus giving the greatest facility for its
installation and reducing the costs of maintenance to a minimum.
4. Ease of taking out and replacing the bars, even whilst the fire is on the grate.
5. The certainty that after each operation the bars will all be restored to the same
plane and consequently will not be liable to be burnt, this being effected by means of
the automatic locking arrangement.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. My improved construction of movable grate in which the fire bars are inter-
changeable and reversible, and the distance between which can be varied and regulated
by means of supports (having pins, or recesses,) mounted on bearer-bars, said grate
being also provided with an automatic arrangement for locking the bars in a uniform
plane after each operation, substantially as described.
2. In a movable grate as characterized in the preceding claim, the arrangement
whereby the fire bars can be set in place through the furnace door, and replaced in
the same way without drawing the fire from the grate, substantially as described.
3. The arrangement for enabling the surface of the grate to be regulated by .
means of the adjustable rods connecting the rocking pieces which give to the bars
their reciprocal movements, substantially as described.
4. The arrangement for obviating friction, by mounting the rocking pieces on knife
edges, in combination with the means for communicating movement to the whole of
the bars by a lever and an extension piece, which latter automatically effects the
engagement and disengagement of the locking device, substantially as described.

page_text: 5. The arrangement of the bearer bars on which the supports e can be adjusted so
as to vary the distance between the fire bars, substantially as described.
6. My improved movable grate constructed and arranged to operate substantially
as herein before described with reference to the accompanying drawings, and for the
purposes set forth.
Dated this 4th day of February 1899.
ERNEST DE PASS,
Chartered Patent Agent, 78, Fleet Street, London, and
5ª, Market Street, Nottingham, Agent for the Applicant.