IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES AND OTHER FIRE-PLACES
Year: 1877

page_text: LETTERS PATENT to Bernard Peard Walker, of Birmingham, in the County of
Warwick, Engineer, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
SUPPLYING FUEL TO FURNACES AND OTHER FIRE-PLACES."
Sealed the 6th November 1877, and dated the 11th May 1877.
PROVISIONAL SPECIFICATION left by the said Bernard Peard Walker at the
Office of the Commissioners of Patents on the 11th May 1877.
BERNARD PEARD WALKER, of Birmingban, in the County of Warwick, Engineer.
"IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES AND OTHER
FIRE-PLACES."
My Invention relates to that description of furnaces or fire-places in which the
fuel is supplied from below, and consists of an improved apparatus for automatically
feeding the furnace or other fire-place in a more simple and efficient manner than
has been heretofore attainable in fire-places of this class, whilst at the same time
the whole of the advantages secured by supplying fuel from underneath the burning
mass in fire-grates are retained.
In carrying out my Invention, the fuel, which is contained in a bunker or hopper
placed at a suitable distance outside the fire-place, is conveyed therefrom into the
grate from below by means of an archimedian screw of uniform diameter through-
out its length, and of coarse pitch, working in a tube, one end of which cominunicates
with the bunker or hopper, whilst the other end, viz., that from which the fuel is
ejected into the fire, is bent upwards, and terminates in a bell mouth underneath
the fire-grate, so that the upper edge or lip of the bell mouth is level with the
surface of the grate, the bell mouth being so formed as to allow the fuel to rise into
the fire without jamming.
In cases where, the thickness of the grate bar, and consequently the height to
which the fuel has to be lifted, is too great to admit of its introduction into the fire
by the simple propulsion of the screw before mentioned alone, I employ a second
screw working in a case, and arranged vertically or at any suitable angle to the first,
the case in which such second screw works forming a branch or T tube connected
with. and leading from the first tube.

page_text: The two screws are driven by hand or power by means of pawls and ratchet
wheels, links, and spur or bevel or other gearing at the required speed, and at
such a relative velocity as to deliver the fuel into the fire without wedging or
jamming.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Bernard Peard Walker in the Great Seal Patent Office on the 9th
November 1877.
BERNARD PEARD WALKER, of Birmingham, in the County of Warwick, Engineer.
"IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES AND OTHER
FIRE-PLACES:"
My said Invention relates to that description of furnaces or fire-places in which
the fuel is supplied from below, and consists of an improved apparatus for auto-
natically feeding the furnace or other fire-place in a more simple and efficient
manner than has been heretofore attainable in fire-places of this class, whilst at the
same time the whole of the advantages secured by supplying fuel from underneath
the burning mass in fire-grates are retained.
In carrying out my said Invention, the fuel, which is contained in a bunker or
hopper placed at a suitable distance outside the fire-place, is conveyed therefrom
into the grate from below by means of two archimedian screws or sets of
archimedian screws, one of which is horizontal, or nearly so, whilst the other is
vertical, or nearly so, the horizontal screw or screws receiving the fuel from the
bunker or hopper, and conveying it to the vertical screw or screws, which elevate it
on to the fire-bars.
The screws (which work in tubes connected with and leading the one from the
other) are driven by hand or power by means of spur, bevel, or other gearing, or
pawls and ratchet wheels, links, or other suitable devices at the required speed, and
at such a relative velocity as to deliver the fuel into the fire without wedging or
jamming.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the two
Figures on the annexed Sheet of Drawings, the same letters of reference indicating
corresponding parts in both the Figures.
Figure 1 of the Drawings represents a vertical section of a furnace, with the
improved feeding apparatus applied thereto, and Figure 2 is a diagram plan
illustrating a modification.
A is the fire-grate (which may be either square, circular, or of any other shape
best adapted for the purpose for which the fire is required) below which grate
(formed with an aperture at that part) there is provided a vertical tube or case B
containing a screw C, and having connected and communicating therewith a hori-
zontal tube or case B¹ enclosing a screw C¹. The latter screw carries on the
extremity of its stem, which passes through and projects beyond the end of the
tube or case, a spur wheel D engaging with a pinion D¹ on one end of a shaft E,
which is mounted in hanging bearings F, F, and driven either by hand or from any
suitable prime mover, whereby a rotary motion is imparted to the screw C¹. Motion
is also simultaneously transmitted to the screw C by means of a bevel pinion G
mounted on the opposite end of the shaft to that on which the spur pinion D¹ is
carried, which bevel pinion is in gear with a bevel wheel G₁ formed on the screw C,
the gearing being so proportioned that the screw C is caused to move at a slightly
greater speed than the screw c¹. The fuel to be supplied to the grate A is contained
in a hopper H situate over the tube B¹, which is provided with an opening a at
that part, so as to admit of the fuel descending into the threads of the screw.
On the apparatus being set in motion the fuel is carried along by the screw C¹

page_text: and delivered to the screw C, by the simultaneous motion of which the fuel will be
gradually elevated on to the bars underneath the fire, the relatively higher speed of
the screw C having the effect of obviating any liability to the jamming or wedging
of the fuel at the point where the two screws meet.
In some cases, in lieu of employing bevel and spur gearing, as shewn, I use
ratchet wheels and pawls, so as to drive both screws with intermittent motion
independently, by which means any stoppage of the working of the apparatus by
the introduction of a large piece of hard material along with the fuel is limited to
one only of the screws.
In soine cases also when the door of the furnace is situate immediately over the
horizontal or feeding screw C', and thereby interferes with the shoot from the
hopper, or prevents it from being placed vertically over the feeding screw, I
arrange the vertical or raising screw C on one side of the feeding screw C¹, as shewn
in the diagram plan Figure 2.
When the fire-place is required to be of such a length that one vertical or raising
screw is insufficient I employ two or more, the tubes of which may be connected
with the tube B₁ of the feeding screw C¹, on either side of it (an example of such
an arrangement being shewn by dotted lines in Figure 2), in which case I construct
the feeding screw C₁ of smaller diameter beyond the first raising screw C, so as to
carry forward one half or some suitably reduced quantity of the fuel brought
out of the hopper, for the supply of the second raising screw C² working in the
tube B².
By the use of my said Invention a uniform heat is obtained, with non-liability to
the production of smoke and a minimum consumption of fuel, the supply being
gradual and constant, and the fuel (delivered underneath the fire) being distributed
laterally, so as to obtain an approximately uniform thickness of fire over the whole
surface of the grate.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into effect,
I would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the combination of two screws or sets of screws arranged
respectively in horizontal, or approximately horizontal and vertical, or approximately
vertical planes, the horizontal screw or screws feeding the fuel to the vertical screw
or screws, which elevate it into the fire, substantially as herein-before described.
In witness whereof, I, the said Bernard Peard Walker, have to this my Speci-
fication set my hand and seal, this Ninth day of November, One thousand
eight hundred and seventy-seven.
BERN. P. WALKER. (L.S.)