Improvements in or relating to Furnace Grates.
Year: 1892

page_text: Date of Application, 18th Oct., 1892
Complete Specification Left, 18th July, 1893-Accepted. 19th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Furnace Grates.
A communication from SALVATORE FOSSATI, of Genoa, in the Kingdom of Italy.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Member of the Institution of Mechanical Engineers, do hereby declare the nature
of this invention to be as follows :-
The object of this invention is as far as possible to obtain the complete combustion
of the fuel placed on the grate, so that the heat developed shall be uniformly
distributed over the entire surface of the fireplace, a result not obtained with grates
in common use, because the supply of atmospheric air is not uniform.
.
This inconvenience is generally due to clinker stopping up the air passages of the
grate.
Combustion under these circumstances is very difficult and cannot be complete,
and therefore much waste is the result as the fuel must be stirred very often to
remove the clinker from the grate, or at least detach it from the bars, so as to
revive combustion; such operation is very troublesome and is very sellom properly
attended to.
This invention is devised to overcome the above named objections and for this
purpose two horizontal shafts are provided upon which are mounted tool holders,
the tools of which can be changed with great facility.
Two prongs guide the tool-holders and the horizontal shafts are spirally grooved
or screw-threaded, the distance between the threads corresponding with the distance
between the bars. These shafts are provided with a star or toothed wheel operated
by an arm or lever mounted on the end of the shaft and worked by a handle. On
turning the handle the above mentioned tools describe a semi-circle around the
fulcrum, or support, fixed upon the plate of the fire-place and so remove the clinker
from the grate, breaking it into small pieces, which fall between the bars into the
ash-pan. These special bars placed transversely to the axis of the fire-place are
supported in bearings which are fixed to the front part of the grate, and bridge-
wall so as to allow the atmospheric air to be uniformly distributed over the whole
surface of the grate and in this way better to utilize all the heat developed. By
this arrangement the flames pass over the sides of the fire-place with more regularity
than in other systems.
It follows that by adopting the before-described apparatus great saving in fuel
is obtained, and furthermore there is secured the advantage of the bars being
continually kept at an even temperature, and consequently a reduction in the
expense for the maintenance of the grates and of the whole fire-place.
When the cleaning out of the clinker has been effected, the screw threaded
shaft, on which is screwed the nut carrying the above mentioned prongs, must be
turned.
On this shaft which is preferably enclosed in a tube is also mounted the handle
by means of which a reversed motion is given thus moving the tools until they
reach the back of the fire-place and so prevent the said knives turning in this
position they remain until they are again required for the cleansing out of the
grate.
The above cleaning appliance can be so constructed as to be set in motion by a
pitch chain operated by a steam or other motor, the principle of the invention, the
special bars and the cleaner remaining unaltered.

page_text: The various parts of the before described apparatus may be varied without
departing from the spirit of the invention.
Dated this 18th day of October 1892
ALFRED J. BOULT,
Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Furnace Grates.
A communication from SALVATORE FOSSATI, of Genoa, in the Kingdom of Italy.
I, ALFRED JULIUS BOULT, of 323, High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement :-
The object of this invention is as far as possible to obtain the complete combustion
of the fuel placed on the grate, so that the heat developed shall be uniformly
distributed over the entire surface of the fireplace, a result not obtained with grates
in common use, because the supply of atmospheric air is not uniform.
This inconvenience is generally due to clinker stopping up the air passages of the
grate.
Combustion under these circumstances is very difficult and cannot be complete,
and therefore much waste is the result as the fuel must be stirred very often to
remove the clinker from the grate, or at least detach it from the bars so as to
revive combustion; such operation is very troublesome and is very seldom properly
attended to.
The invention will be best understood by reference to the accompanying drawings,
in which
Figure 1 is an end or front elevation of the apparatus.
Figure 2 part of the apparatus in plan with parts broken away for clearness,
Figure 3 is a longitudinal section of a portion of a furnace tube with the apparatus
fitted, and
Figure 4 shows details.
Like letters represent like parts throughout the drawings.
The apparatus consists broadly of two shafts carrying knives or cutters adapted
to be turned up between the fire bars so as to remove and break the clinkers and
the apparatus for operating this mechanism.
In the drawings I have shown the apparatus applied to a corrugated furnace
tube but this is immaterial as the apparatus works in conjunction with the fire bars
and may be applied in any convenient manner.
A are shafts preferably square upon which are sleeves B carrying the knives or
blades C the shafts being turned or reciprocated by means of the handles A' so as
to move each knife through the arc of a circle from the lowest position shown by
the knife C upon the right hand side of Figure 1 to the furthest position in the
opposite extreme as shown by the dotted lines upon the left hand side of Figure 1.
Each sleeve B is provided with a groove B¹ in which fits a fork D' projecting
from a sleeve D having a projection D2 adapted to engage with a screw or
equivalent thread or groove E¹ formed in the shaft E so that when the shaft E is
turned the sleeve D is moved along E the fork D¹ imparting this movement to the
sleeve B and knife C. To keep it clean the shaft E is preferably enclosed by a
tube F having a longitudinal opening or slot F¹ through which the extension D³ of
the sleeve D passes as will be readily understood. Each shaft A carries an arm G
upon which is pivotted a gravity or spring controlled pawl G' resting against a
stop G2 upon the arm G as indicated in Figure 1 and adapted when the shaft is
being turned in one direction to engage with the arms H of a star wheel secured
upon the shaft E and when moved in the opposite direction to slip past the arms H.
Each shaft E is also provided with arms I or a hand wheel or equivalent device by

page_text: which it can be turned for the purpose of returning the knives C to the commence-
ment of their journey say at the back of the apparatus after they have finished
their outward journey. The operative parts of the mechanism are so proportioned
that the pawl G' at each reciprocation of the handle A¹ and shaft A turns the star
wheel and consequently the shaft E to the proper extent to cause the sleeve D to
travel the distance necessary to move the knife C from one fire bar to the next and.
it will be observed that this movement only takes place while the knife C is below
the fire bars J and still descending so that there is no danger of the knife striking
the fire bars while it is being moved along. When the knife is being moved in an
upward direction the pawl G¹ slips over the tooth H' of the star wheel without
imparting any movement to the shaft E.
The shafts A may be connected together so that it would only be necessary to
directly operate one of them or they may be operated independently. To prevent
the knives from travelling too far stops of any suitable kind, say the pins or
bolts K may be placed through or upon the shaft E or the screw thread may be
stopped off or filled up at the proper point so as to prevent the sleeve D from.
travelling too far. The shafts A may be allowed to turn to the required extent.
say conveniently to the extent of nearly half a revolution.
To prevent the firebars being lifted off their supports by the action of the
knives it is preferred to form them as shown in Figure 1 with two projections J1 J*
at each end. The projection J' is slanted as is usual with the end of a fire bar
and engages with a correspondingly slanted bearer L as shown; the second
projection J2 is adapted to rest upon any suitable bearer M and also prevents the
bar from being lifted up by engaging with the projecting plate N secured along
the inside of the furnace flue or otherwise according to the application of the
apparatus. Some of the fire bars at the front of the furnace say conveniently the
first two are adapted to be lifted out by reason of the plate N being stopped off at
that part as indicated in dotted lines in the plan Figure 2. These two bars can
therefore be removed and the other bars may then be moved to the front and
successively taken out through the openings provided by the cessation of the
plates N, the knives C being kept out of the way say as indicated in Figure 1
during this operation.
The shafts A and E and the various parts of the apparatus not more specifically
described may be supported upon any suitable brackets standards or other supporting
devices as found most convenient; in the drawings the shafts A are shown
supported by standards O having arms O' which carry the shafts E.
To use this apparatus the operator starts with the knife C at preferably the
back of the apparatus and swinging handle A¹ he turns the shaft A partly round
and back again thus moving the knife C and bringing it up between the bars, the
operation of the pawl G¹ engaging with the star wheel H at each reciprocation of
the handle turning the shaft E intermittently and thus moving the knife C inter-
mittently along from space to space between the bars until the whole of the bars
have been cleared when the operator can move the knife back again to the starting
point by turning the shaft E in the reverse direction by means of the hand wheel
or equivalent I. If the shafts A are coupled together this operation will have
cleared the whole of the bars but if they are independent then having completed
the operation with one half of the apparatus he will go through the same process
with the other and thus remove the whole of the clinkers from the bars.
The above cleaning appliance can be so constructed as to be set in motion by a
pitch chain operated by a steam or other motor, the principle of the invention, the
special bars and the cleaner remaining unaltered.
Although I have described the shaft E as provided with a worm groove E¹ it
will be understood that so long as the necessary movement is imparted to the
sleeve D the actual construction of these parts may be varied; for example, a
twisted square shaft E and a sleeve D with a square opening would produce the
same result, or a helical worm rotating around a fixed central shaft could also be
arranged to produce the same result.

page_text: Having now particularly described and ascertained the nature of the said.
invention (as communicated to me by my foreign correspondent) and in what
manner the same is to be performed I declare that what I claim is :-
:
1. The combination and arrangement of parts constituting the complete clinker
removing device substantially as described and illustrated in the accompanying
drawings.
2. In a clinker removing device the combination with a shaft A of a knife or
blade such as C adapted to be turned by the shaft so as to pass between the fire
bars for the purpose of removing the clinkers and to be intermittently moved
along the shaft so as to clear the bars successively substantially as described and
illustrated in the accompanying drawings.
3. In a clinker removing device the combination with a shaft such as A carrying
a knife or blade such as C adapted to turn with the shaft and to travel along it of
a second shaft or screw such as E intermittently rotated by or from the shaft A
for the purpose of moving the blade along the shaft A substantially as described
and illustrated in the accompanying drawings.
4. In a clinker removing device the combination of shaft A sleeve B knife C
fork D' sleeve D and screwed shaft E substantially as and for the purpose described
and illustrated in the accompanying drawings.
5. In a clinker removing device the combination with a knife_carrying shaft A
and worm shaft E of an arm such as G pawl G¹ and star wheel H H¹ substantially
as and for the purpose described and illustrated in the accompanying drawings.
6. In a clinker removing device and as a means of holding or releasing the fire
bars the combination with the projections J1 J2 of the fire bar of the plate L
stopped off at the end substantially as described and illustrated in the accompanying
drawings.
Dated this 18th day of July 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.